Reconstruction of Knee Defects Using Pedicled Gastrocnemius Muscle Flap with Split-Thickness Skin Grafting: A Single Surgeon's Experience with 21 Patients.

PubMed

Kilic, Ali; Denney, Brad; de la Torre, Jorge

2018-05-31

Generally, reconstruction of knee defects with exposed bone, joint, tendon, and/or hardware requires a vascularized muscle flap for coverage. Although there are several surgical options for a knee defect reconstruction, the pedicled gastrocnemius muscle still remains the workhorse flap. Although this flap is commonly used for knee defect reconstruction and the technique is described very well, there is an absence of information in the literature detailing the technique of harvesting and insetting of the gastrocnemius flap step by step with illustrations. The purpose of this article is to describe in detail the technique to reconstruct defects of the knee with pedicled gastrocnemius muscle flap as well as to present demographics and surgical results of 21 patients who had knee reconstruction with a pedicled gastrocnemius muscle flap and split-thickness skin grafting. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Prefabricated scalping forehead flap with skeletal support.

PubMed

Fujiwara, Masao; Suzuki, Ayano; Mizukami, Takahide; Terai, Tsutomu; Fukamizu, Hidekazu

2009-07-01

It is difficult to reconstruct a nose with adequate shape, color, and texture in patients who have full-thickness nasal defects with extensive loss of skeletal support. The scalping forehead flap is a reliable technique for nasal reconstruction. To our knowledge, however, there have been no reports about a prefabricated scalping forehead flap with a bone graft as skeletal support. In the case reported here, a prefabricated scalping forehead flap combined with an iliac bone graft as skeletal support was used to successfully reconstruct a full-thickness defect of the nose associated with partial frontal bone loss and complete loss of the nasal bones. Acceptable functional and aesthetic results were achieved. This method may be a good alternative for reconstruction of full-thickness nasal defects with extensive loss of skeletal support.

Laser in situ keratomileusis enhancements with the Ziemer FEMTO LDV femtosecond laser following previous LASIK treatments.

PubMed

Pietilä, Juhani; Huhtala, Anne; Mäkinen, Petri; Uusitalo, Hannu

2013-02-01

The aim of this paper is to present the accuracy, predictability, and safety outcomes of LASIK enhancements performed with the FEMTO LDV femtosecond laser (Ziemer Ophthalmic Systems, Port, Switzerland) and the Allegretto Wave Concerto 500 Hz excimer laser (Wavelight AG, Erlangen, Germany), following previous LASIK treatments. FEMTO LDV was used for flap creation in 85 previously LASIK-treated eyes of 62 patients. The intended flap thickness was 90 μm in 81 eyes and 140 μm in 4 eyes. The size of the suction ring was 9.0 mm in 72 eyes and 9.5 mm in 13 eyes. Flap dimensions were measured and correlated to preoperative characteristics. With the intended flap thickness of 90 μm in previously LASIK-treated eyes, the actual flap thickness was 90.2 ± 6.6 μm (range 80-122), and the flap diameter was 9.2 ± 0.2 mm (range 8.7-9.9). The mean hinge length was 4.0 ± 0.2 mm (range 3.0-4.8). Flap thickness correlated positively with patient age and hinge length. Complications were reported in 12 eyes (14.1 %). Most of the complications were very mild, and none of them prevented further refractive laser treatment. One eye lost two Snellen lines of best spectacle-corrected visual acuity. Femtosecond LASIK enhancement is warranted only in rare cases. Surgical experience is needed and special caution must be practiced. For cases of a primary free cap, femtosecond LASIK is not recommended.

Biochemical and Cellular Assessment of Acetabular Chondral Flaps Identified During Hip Arthroscopy.

PubMed

Hariri, Sanaz; Truntzer, Jeremy; Smith, Robert Lane; Safran, Marc R

2015-06-01

To analyze chondral flaps debrided during hip arthroscopy to determine their biochemical and cellular composition. Thirty-one full-thickness acetabular chondral flaps were collected during hip arthroscopy. Biochemical analysis was undertaken in 21 flaps from 20 patients, and cellular viability was determined in 10 flaps from 10 patients. Biochemical analysis included concentrations of (1) DNA (an indicator of chondrocyte content), (2) hydroxyproline (an indicator of collagen content), and (3) glycosaminoglycan (an indicator of chondrocyte biosynthesis). Higher values for these parameters indicated more healthy tissue. The flaps were examined to determine the percentage of viable chondrocytes. The percentage of acetabular chondral flap specimens that had concentrations within 1 SD of the mean values reported in previous normal cartilage studies was 38% for DNA, 0% for glycosaminoglycan, and 43% for hydroxyproline. The average cellular viability of our acetabular chondral flap specimens was 39% (SD, 14%). Only 2 of the 10 specimens had more than half the cells still viable. There was no correlation between (1) the gross examination of the joint or knowledge of the patient's demographic characteristics and symptoms and (2) biochemical properties and cell viability of the flap, with one exception: a degenerative appearance of the surrounding cartilage correlated with a higher hydroxyproline concentration. Although full-thickness acetabular chondral flaps can appear normal grossly, the biochemical properties and percentage of live chondrocytes in full-thickness chondral flaps encountered in hip arthroscopy show that this tissue is not normal. There has been recent interest in repairing chondral flaps encountered during hip arthroscopy. These data suggest that acetabular chondral flaps are not biochemically and cellularly normal. Although these flaps may still be valuable mechanically and/or as a scaffold in some conductive or inductive capacity, further study is required to assess the clinical benefit of repair. Copyright © 2015 Arthroscopy Association of North America. Published by Elsevier Inc. All rights reserved.

Bilateral superiorly based full-thickness nasolabial island flaps for closure of residual anterior palatal fistulas in an unoperated elderly patient.

PubMed

Erçöçen, A R; Yilmaz, S; Saydam, M

2003-01-01

Unoperated bilateral complete cleft lip and palate in an adult or elderly patient is seen rarely, and the existence of unoperated clefts is a result of unfavorable economic and social circumstances. We report an unoperated 65-year-old patient with bilateral complete cleft lip and palate and present our preference for the surgical management. Repair of the bilateral complete cleft lip and palate was successfully carried out using straight-line closure for the bilateral cleft lip and two-flap pushback palatoplasty with superiorly based lateral port control pharyngeal flap for the wide cleft palate at the first stage, and large residual anterior palatal fistulas were closed using bilateral superiorly based (retrograde flow) full-thickness nasolabial island flaps at the second stage. To our knowledge based on a review of the literature, this is the first report of an elderly patient with bilateral complete cleft lip and palate and the first application of bilateral superiorly based (retrograde flow) full-thickness nasolabial island flaps for closure of large residual anterior palatal fistulas or alveolar clefts. The bilateral superiorly based (retrograde flow) full-thickness nasolabial island flap may be a good solution in large anterior palatal defects using unilaterally or bilaterally in a single stage with minimal donor site morbidity, in which there is not enough tissue for local repair or if previous attempts are unsuccessful.

Tissue-engineered oral mucosa grafts for intraoral lining reconstruction of the maxilla and mandible with a fibula flap.

PubMed

Sieira Gil, Ramón; Pagés, Carles Martí; Díez, Eloy García; Llames, Sara; Fuertes, Ada Ferrer; Vilagran, Jesús Lopez

2015-01-01

Many types of soft tissue grafts have been used for grafting or prelaminating bone flaps for intraoral lining reconstruction. The best results are achieved when prelaminating free flaps with mucosal grafts. We suggest a new approach to obtain keratinized mucosa over a fibula flap using full-thickness, engineered, autologous oral mucosa. We report on a pilot study for grafting fibula flaps for mandibular and maxilla reconstruction with full-thickness tissue-engineered autologous oral mucosa. We describe 2 different techniques: prelaminating the fibula flap and second-stage grafting of the fibula after mandibular reconstruction. Preparation of the full-thickness tissue-engineered oral mucosa is also described. The clinical outcome of the tissue-engineered intraoral lining reconstruction and response after implant placement are reported. A peri-implant granulation tissue response was not observed when prelaminating the fibula, and little response was observed when intraoral grafting was performed. Tissue engineering represents an alternative method by which to obtain sufficient autologous tissue for reconstructing mucosal oral defects. The full-thickness engineered autologous oral mucosa offers definite advantages in terms of reconstruction planning, donor site morbidity, and quality of the intraoral soft tissue reconstruction, thereby restoring native tissue and avoiding peri-implant tissue complications. Copyright © 2015 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Dry eyes and corneal sensation after laser in situ keratomileusis with femtosecond laser flap creation Effect of hinge position, hinge angle, and flap thickness.

PubMed

Mian, Shahzad I; Li, Amy Y; Dutta, Satavisha; Musch, David C; Shtein, Roni M

2009-12-01

To determine whether corneal sensation and dry-eye signs and symptoms after myopic laser in situ keratomileusis (LASIK) surgery with a femtosecond laser are affected by varying hinge position, hinge angle, or flap thickness. University-based academic practice, Ann Arbor, Michigan, USA. This prospective randomized contralateral-eye study evaluated eyes after bilateral myopic LASIK with a femtosecond laser (IntraLase). Superior and temporal hinge positions, 45-degree and 90-degree hinge angles, and 100 microm and 130 microm corneal flap thicknesses were compared. Postoperative follow-up at 1 week and 1, 3, 6, and 12 months included central Cochet-Bonnet esthesiometry, the Ocular Surface Disease Index questionnaire, a Schirmer test with anesthesia, tear breakup time (TBUT), corneal fluorescein staining, and conjunctival lissamine green staining. The study evaluated 190 consecutive eyes (95 patients). Corneal sensation was reduced at all postoperative visits, with improvement over 12 months (P<.001). There was no difference in corneal sensation between the different hinge positions, angles, or flap thicknesses at any time point. The overall ocular surface disease index score was increased at 1 week, 1 month, and 3 months (P<.0001, P<.0001, and P = .046, respectively). The percentage of patients with a TBUT longer than 10 seconds was significantly lower at 1 week and 1 month (P<.0001). Dry-eye syndrome after myopic LASIK with a femtosecond laser was mild and improved after 3 months. Corneal flap hinge position, hinge angle, and thickness had no effect on corneal sensation or dry-eye syndrome.

Comparison of Sub-Bowman Keratoplasty Laser In situ Keratomileusis Flap Properties between Microkeratome and Femtosecond Laser.

PubMed

Fazel, Farhad; Ghoreishi, Mohammad; Ashtari, Alireza; Arefpour, Reza; Namgar, Mohammad

2017-01-01

Since thin and high-quality flaps produce more satisfactory surgical outcomes, flaps created by mechanical microkeratomes are more economical as compared with femtosecond lasers, and no Iranian study has concentrated laser in situ keratomileusis (LASIK) flap peculiarities between Moria Sub-Bowman keratoplasty (SBK) microkeratomes and LDV femtoseconds, the present study compares and contrasts them. This cross-sectional study was done on all patients who underwent LASIK surgery 1-month before this study. Thirty eyes were divided into per group. Flaps in the first group and second group were created, respectively, using Moria SBK microkeratome and LDV femtosecond laser. The other stages of LASIK were done equally in both groups. One month after surgery, the thickness of flaps was measured by anterior segment optical coherence tomography in five regions of flaps. Corneal anterior density was calculated and recorded 1-month after surgery using pentacam and by employing optical densitometry in a distance in the limit range of 0-6 mm from cornea center. Densitometry measurements were obtained and expressed in standardized grayscale units (GSUs). Postsurgery densitometry results reveal that anterior densities of cornea in limit range of 0-2 mm in groups of LDV femtosecond laser and Moria microkeratome are 21.35 ± 0.87 GSU and 22.85 ± 1.25 GSU, respectively. Accordingly, these two groups are significantly different in this regard ( P < 0.001). Moreover, anterior densities of the cornea in the limit range of 2-6 mm in these groups are 19.66 ± 0.99 GSU and 20.73 ± 1.24 GSU, respectively. Accordingly, these two groups are significantly different in this regard ( P = 0.04). There is a lower mean of flap thickness in the case of LDV femtosecond laser. Femtosecond laser method is greatly preferred as compared with Moria microkeratome because of greater homogeneity in flap thickness, smaller thickness, and lower density in optical zone.

Effects of Skin Thickness on Cochlear Input Signal using Transcutaneous Bone Conduction Implants

PubMed Central

Mattingly, Jameson K.; Greene, Nathaniel T.; Jenkins, Herman A.; Tollin, Daniel J.; Easter, James R.; Cass, Stephen P.

2015-01-01

Hypothesis Intracochlear sound pressures (PIC) and velocity measurements of the stapes, round window, and promontory (VStap/RW/Prom) will show frequency dependent attenuation using magnet-based, transcutaneous bone-conduction implants (TCBCI) in comparison to direct-connect, skin-penetrating implants (DCBCI). Background TCBCIs have recently been introduced as alternatives to DCBCIs. Clinical studies have demonstrated elevated high-frequency thresholds for TCBCIs as compared to DCBCIs; however, little data exists examining the direct effect of skin thickness on the cochlear input signal using TCBCIs. Methods Using seven cadveric heads, PIC was measured in the scala vestibuli and tympani with fiber-optic pressure sensors concurrently with VStap/RW/Prom via laser Doppler vibrometry. Ipsilateral titanium implant fixtures were placed and connected to either a DCBCI or TCBCI. Soft tissue flaps with varying thicknesses (no flap, 3, 6, and 9 mm) were placed successively between the magnetic plate and sound processor magnet. A bone-conduction transducer coupled to custom software provided pure tone stimuli between 120 to 10240 Hz. Results Stimulation via the DCBCI produced the largest response magnitudes. The TCBCI showed similar PSV/ST and VStap/RW/Prom with no intervening flap, and a frequency-dependent, non-linear reduction of magnitude with increasing flap thickness. Phase shows a comparable dependence on transmission delay as the acoustic baseline, and the slope steepens at higher frequencies as flap thickness increases suggesting a longer group delay. Conclusions Proper soft tissue management is critical to optimize the cochlear input signal. The skin thickness related effects on cochlear response magnitudes should be taken into account when selecting patients for a TCBCI. PMID:26164446

The changes in resting anal pressure after performing full-thickness rectal advancement flaps.

PubMed

Balciscueta, Zutoia; Uribe, Natalia; Mínguez, Miguel; García-Granero, Eduardo

2017-09-01

Advancement flap is an accepted approach for treating complex fistula-in-ano.The purpose was to evaluate the changes in resting pressure along the anal canal after performing a full-thickness flap. Manometric review of patients who have undergone a full-thickness rectal advancement flap procedure for complex anal fistulas of cryptoglandular origin. Recurrence and continence were evaluated. Resting Anal Pressure was assessed along the anal canal by two measures: maximum resting pressure(MRP) and inferior resting pressure(IRP) at 0.5 cm from the anal verge. 119 patients were evaluated. Overall recurrence rate was5.9%. Anal continence was maintained intact in 76.5%. Manometric study showed a significant decrease in postoperative MRP(90.6 ± 31.9 to 45.2 ± 20 mmHg; p < 0.001), while IRP values did not differ significantly(28.2 ± 18.3 to 23.2 ± 13.5 mmHg; p = 0.1). Performing a full-thickness rectal flap causes a decrease of the MRP in the middle third of the anal canal, due to the inclusion of the internal sphincter in flap. It seems crucial to preserve the distal internal sphincter intact as it helps both to maintain the resting pressure in the lower third and avoid deformities of the anal margin. Copyright © 2017 Elsevier Inc. All rights reserved.

LASIK flap characteristics using the Moria M2 microkeratome with the 90-microm single use head.

PubMed

Aslanides, Ioannis M; Tsiklis, Nikolaos S; Astyrakakis, Nikolaos I; Pallikaris, Ioannis G; Jankov, Mirko R

2007-01-01

To evaluate the accuracy and consistency of corneal flap thickness, horizontal diameter, and hinge size with the Moria M2 90-microm single use head. Fifty-two myopic patients (104 eyes), mean age 32.6 years, underwent bilateral LASIK with a superior hinged flap using the Moria M2 microkeratome (90-microm single use head). Prospective evaluation included flap thickness (subtraction method), diameter, hinge size, interface particles, intraoperative complications, and visual recovery. The mean preoperative spherical equivalent refraction was -5.72 +/- 2.59 diopters (D) (range: -2.88 to -10.75 D) and -5.84 +/- 2.73 D (range: -3.13 to -9.38 D) for right and left eyes, respectively. The mean preoperative central corneal thickness was 548 +/- 24 microm and 547 +/- 25 microm for right and left eyes, respectively. The mean preoperative steepest K was 44.12 +/- 1.28 D and 44.41 +/- 1.27 D for right and left eyes, respectively. Corneal diameter (white-to-white) was 12 +/- 0.4 mm and 11.9 +/- 0.4 mm for right and left eyes, respectively. The mean postoperative flap thickness was 109 +/- 18 microm (range: 67 to 152 microm) and 103 +/- 15 microm (range: 65 to 151 microm) for right and left eyes, respectively. The mean postoperative flap diameter was 9.4 +/- 0.3 mm (expected mean according to the nomogram given by the company was 9.5 mm). The mean postoperative hinge chord was 4.4 +/- 0.4 mm (expected mean 4.2 mm). No interface particles were detected on slit-lamp examination. The Moria M2 90-microm single use head is safe with reasonable predictability for LASIK flap creation.

Tracheal reconstruction with a pleuroperiosteal flap.

PubMed

Krespi, Y P; Biller, H F; Baek, S M

1983-12-01

Reconstruction of extensive tracheal defects remains a difficult surgical problem. In many experiments restoration of tracheal mucosa by autogenous or homologous soft tissue grafts has usually failed because of rejection or tracheal obstruction. This experimental work employed a two-stage surgical procedure that allowed reconstruction of extensive circumferential full-thickness defects of the trachea. Stage I involved the creation of a vascularized pleuroperiosteal flap that was formed into a rigid tube around a Silastic stent. Stage II consisted of creation of a full-thickness circumferential tracheal defect and repair with the flap in those animals in which a suitable rigid tube had been formed. The results of these experiments argue strongly that a vascularized composite pleuroperiosteal flap can produce an adequate tracheal replacement.

Comparative study of 2 commissural dorsal flap techniques for the treatment of congenital syndactyly.

PubMed

Mallet, Cindy; Ilharreborde, Brice; Jehanno, Pascal; Litzelmann, Estelle; Valenti, Philippe; Mazda, Keyvan; Penneçot, Georges-François; Fitoussi, Franck

2013-03-01

Many commissural reconstruction techniques have been described for the treatment of syndactyly. This study is the first to compare long-term results of 2 commissural dorsal flap procedures (T-flap and omega-flap). Fifty-nine web-spaces in 39 patients, operated on between 1991 and 2008, were retrospectively analyzed. Thirty-six T-flap and 23 omega-flap procedures were performed using full-thickness skin graft in every case for digital resurfacing. Factors that could affect the long-term outcome were collected, including development of web-creep, clinodactyly, and flexion contracture. Patients were reviewed with a mean follow-up of 5 years and 8 months. Preoperative complexity of syndactyly influenced the development of clinodactyly and flexion contracture. Among the patients who developed clinodactyly, 96% had surgery for complex syndactyly. No difference was found between the 2 flap methods concerning digital deformation and mobility. However, web-creep occurred more frequently after T-flap than after omega-flap procedures (17% vs. 5%). The combination of either dorsal commissural T-flaps or omega-flaps with full-thickness graft to resurface digits is a reliable technique for the treatment of syndactyly with satisfactory functional and cosmetic results. Long-term results are not influenced by the type of flap. Nevertheless, the omega-flap technique, using 2 triangular lateral-palmar flaps, avoids use of skin graft to cover lateral-palmar aspects of the new commissure, consequently reducing the incidence of web-creep. In cases of syndactyly, the primary prognostic factor is whether the patient has simple or complex syndactyly. In complex syndactyly, the risk of long-term unfavorable results is higher. When complex complicated syndactyly is involved, postoperative complication rates increase. Level III.

Development of a primary melanoma in situ within a full-thickness skin graft overlying a free muscle flap: a case report.

PubMed

Dabek, Robert J; Baletic, Nemanja; McUmber, Harrison; Nahed, Brian; Haynes, Alex; Eberlin, Kyle R; Bojovic, Branko

2018-01-01

The development of a primary melanoma within the confines of free tissue transfer is a rare occurrence. In this report, we describe the development of a primary melanoma in situ within a full-thickness skin graft overlying a free latissimus dorsi muscle flap used to cover a scalp defect.

Visumax femtolasik versus Moria M2 microkeratome in mild to moderate myopia: efficacy, safety, predictability, aberrometric changes and flap thickness predictability.

PubMed

Torky, Magda A; Al Zafiri, Yousif A; Khattab, Abeer M; Farag, Rania K; Awad, Eman A

2017-07-17

This is an interventional prospective clinical study which was conducted to evaluate the efficacy, safety, predictability, ocular aberrations, and flap thickness predictability of Visumax femtosecond laser (FSL) compared to Moria M2 microkeratome (MK) in mild to moderate myopia. This study included 60 eyes who were divided into two groups. Thirty eyes in group (I) in which the flap was created with Visumax FSL, while in group II (30 eyes) the Moria M2 MK was used. Keratometric, refractive, and aberrometric measurements were compared preoperatively and 3 months postoperatively. The intraoperative subtraction pachymetry (the SP 100 Handy pachymeter (Tomey, Nagoya, Japan) was used for preoperative pachymetry and flap thickness measurement. No significant difference was found between the two groups in regards to postoperative manifest sphere, spherical equivalent, astigmatism, safety indices nor ocular aberrations. Twenty six eyes (86.6%) in group I and 23 eyes in group II (76.6%) were within ±0.5D of the intended correction and 23 eyes (76.6%) in group I and 15 eyes in group II (50%) were within ±0.25D of the intended correction. In group I, the mean postoperative actual flap thickness was 100.12 ± 16.1 μm (81 to 122 μm), while in group II, it was 104.6 ± 20.1 μm (62 to 155 μm). The difference was statistically significant (p = 0.001). Both Visumax and Moria M2 MK are safe and effective in treating myopia with no statistically significant difference in induction of ocular aberrations but with potential advantage for Visumax regarding predictability. More accurate flap thickness is achieved with Visumax femtolasik. This study was retrospectively registered on 19/6/2017. Trial registration number NCT03193411 , clinicalTrials.gov .

The revascularization of pedicle skin flaps in pigs: a functional and morphologic study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Young, C.M.

1982-10-01

Functional and morphologic changes occurring during the revascularization of pedicle flaps have been investigated in the skin of pigs. The skin flaps, 16 cm long by 4 cm wide, were based on a row of segmental vessels arising from the internal mammary artery. Comparative measurements were made in flapped and normal skin. The inherent blood supply in the pedicle of the flap was unable to maintain the whole of the flap in a viable state. Flap viability was ascertained at surgery by the use of the intravital dye Disulphine blue. Injections of the dye after surgery gave a less accuratemore » prediction of viability than when dye was injected prior to surgery. Revascularization between the flap and surrounding skin was evident 3 to 4 days postoperatively at the distal, most hypoxic part of the viable flap. The whole flap had a collateral vascular supply 7 to 10 days after surgery. Isotope clearance studies showed that the greatest functional changes occurred in the distal third of the viable flap, where, after initially slowing, the clearance rate became faster than in normal skin (day 5). Potassium extraction studies indicated similar changes. However, an increase in the red-cell volume on day 1 suggested that vascular shunting was occurring. The results of the morphologic studies indicated a correlation between the number of blood vessels per unit area, the thickness of the dermis, and the recorded functional changes. Seven days after surgery, when isotope clearance rates were very rapid, there was a significant increase in the vascular density and dermal thickness.« less

Numerical and experimental investigations on unsteady aerodynamics of flapping wings

NASA Astrophysics Data System (ADS)

Yu, Meilin

The development of a dynamic unstructured grid high-order accurate spectral difference (SD) method for the three dimensional compressible Navier-Stokes (N-S) equations and its applications in flapping-wing aerodynamics are carried out in this work. Grid deformation is achieved via an algebraic blending strategy to save computational cost. The Geometric Conservation Law (GCL) is imposed to ensure that grid deformation will not contaminate the flow physics. A low Mach number preconditioning procedure is conducted in the developed solver to handle the bio-inspired flow. The capability of the low Mach number preconditioned SD solver is demonstrated by a series of two dimensional (2D) and three dimensional (3D) simulations of the unsteady vortex dominated flow. Several topics in the flapping wing aerodynamics are numerically and experimentally investigated in this work. These topics cover some of the cutting-edge issues in flapping wing aerodynamics, including the wake structure analysis, airfoil thickness and kinematics effects on the aerodynamic performances, vortex structure analysis around 3D flapping wings and the kinematics optimization. Wake structures behind a sinusoidally pitching NACA0012 airfoil are studied with both experimental and numerical approaches. The experiments are carried out with Particle Image Velocimetry (PIV) and two types of wake transition processes, namely the transition from a drag-indicative wake to a thrust-indicative wake and that from the symmetric wake to the asymmetric wake are distinguished. The numerical results from the developed SD solver agree well with the experimental results. It is numerically found that the deflective direction of the asymmetric wake is determined by the initial conditions, e.g. initial phase angle. As most insects use thin wings (i. e., wing thickness is only a few percent of the chord length) in flapping flight, the effects of airfoil thickness on thrust generation are numerically investigated by simulating the flow fields around a series of plunging NACA symmetric airfoils with thickness ratio ranging from 4.0% to 20.0% of the airfoil chord length. The contribution of viscous force to flapping propulsion is accessed and it is found that viscous force becomes thrust producing, instead of drag producing, and plays a non-negligible role in thrust generation for thin airfoils. This is closely related to the variations of the dynamics of the unsteady vortex structures around the plunging airfoils. As nature flyers use complex wing kinematics in flapping flight, kinematics effects on the aerodynamic performance with different airfoil thicknesses are numerically studied by using a series of NACA symmetric airfoils. It is found that the combined plunging and pitching motion can outperform the pure plunging or pitching motion by sophisticatedly adjusting the airfoil gestures during the oscillation stroke. The thin airfoil better manipulates leading edge vortices (LEVs) than the thick airfoil (NACA0030) does in studied cases, and there exists an optimal thickness for large thrust generation with reasonable propulsive efficiency. With the present kinematics and dynamic parameters, relatively low reduced frequency is conducive for thrust production and propulsive efficiency for all tested airfoil thicknesses. In order to obtain the optimal kinematics parameters of flapping flight, a kinematics optimization is then performed. A gradient-based optimization algorithm is coupled with a second-order SD Navier-Stokes solver to search for the optimal kinematics of a certain airfoil undergoing a combined plunging and pitching motion. Then a high-order SD scheme is used to verify the optimization results and reveal the detailed vortex structures associated with the optimal kinematics of the flapping flight. It is found that for the case with maximum propulsive efficiency, there exists no leading edge separation during most of the oscillation cycle. In order to provide constructive suggestions to the design of micro-air-vehicles (MAVs), 3D simulations of the flapping wings are carried out in this work. Both the rectangular and bio-inspired wings with different kinematics are investigated. The formation process of two-jet-like wake patterns behind the finite-span flapping wing is found to be closely related to the interaction between trailing edge vortices and tip vortices. Then the effects of the wing planforms on the aerodynamics performance of the finite-span flapping wings are elucidated in terms of the evolution and dynamic interaction of unsteady vortex structures.

An experimental study of pressures on 60 deg Delta wings with leading edge vortex flaps

NASA Technical Reports Server (NTRS)

Marchman, J. F., III; Terry, J. E.; Donatelli, D. A.

1983-01-01

An experimental study was conducted in the Virginia Tech Stability Wind Tunnel to determine surface pressures over a 60 deg sweep delta wing with three vortex flap designs. Extensive pressure data was collected to provide a base data set for comparison with computational design codes and to allow a better understanding of the flow over vortex flaps. The results indicated that vortex flaps can be designed which will contain the leading edge vortex with no spillage onto the wing upper surface. However, the tests also showed that flaps designed without accounting for flap thickness will not be optimum and the result can be oversized flaps, early flap vortex reattachment and a second separation and vortex at the wing/flap hinge line.

Avoiding secondary skin graft donor site morbidity in the fibula free flap harvest.

PubMed

Kim, Paul D; Fleck, Terry; Heffelfinger, Ryan; Blackwell, Keith E

2008-12-01

To compare donor site morbidity in patients who have undergone fibula free flap reconstruction in which the skin graft was taken from the expected cutaneous paddle of the fibula with the known complications of the popular technique of obtaining a split-thickness skin graft (STSG) from a secondary donor site. Cohort study. The tertiary care centers at Loma Linda University Medical Center and University of California, Los Angeles, Medical Center. From September 1, 2006, to March 30, 2007, 30 patients underwent fibula free flap harvest by 2 surgeons at separate tertiary care centers. Twenty-one of those procedures took place at the University of California, Los Angeles, and 9 at Loma Linda University. Patients included 15 men (50%) and 15 women (50%), with a mean age of 58 (range, 19-88) years. All 30 patients underwent fibula free flap harvest with a split-thickness skin graft (graft thickness, 0.04 cm), obtained from osteocutaneous paddle using a 5.1-cm-wide dermatome, as well as oral cavity and oropharyngeal reconstruction with the de-epithelialized skin paddle. Measures of donor site morbidity, including graft failure and wound breakdown, and measures of recipient site morbidity, including flap failure, hardware complications, intraoral complications, and the need for additional surgery. Of the 30 patients who underwent this procedure, 4 had partial skin graft failures, for a complete skin graft survival of 87%. There were no complete skin graft losses. Regarding the fibula osteocutaneous free flap, there were no complete flap losses, 1 skin paddle necrosis that required debridement, 2 postoperative orocutaneous fistulas, 1 case of infected/extruded hardware, and 1 adhesion formation that required additional surgery for lysis of adhesion and placement of the split-thickness skin graft. The outlined novel technique has similar rates of free flap survival and skin graft take compared with previously described methods. Harvesting the skin graft over the expected osteocutaneous paddle results in decreased lower extremity morbidity by providing equivalent graft tissue for donor site closure and eliminating the morbidity of a secondary donor site. As long as there will not be 2 large opposing grafted surfaces, this technique should be considered when harvesting fibula free flaps for reconstruction of oromandibular resection defects, especially in cancers of the alveolar ridge and floor of the mouth.

Face resurfacing using a cervicothoracic skin flap prefabricated by lateral thigh fascial flap and tissue expander.

PubMed

Li, Qingfeng; Zan, Tao; Gu, Bin; Liu, Kai; Shen, Guoxiong; Xie, Yun; Weng, Rui

2009-01-01

Resurfacing of facial massive soft tissue defect is a formidable challenge because of the unique character of the region and the limitation of well-matched donor site. In this report, we introduce a technique for using the prefabricated cervicothoracic skin flap for facial resurfacing, in an attempt to meet the principle of flap selection in face reconstructive surgery for matching the color and texture, large dimension, and thinner thickness (MLT) of the recipient. Eleven patients with massive facial scars underwent resurfacing procedures with prefabricated cervicothoracic flaps. The vasculature of the lateral thigh fascial flap, including the descending branch of the lateral femoral circumflex vessels and the surrounding muscle fascia, was used as the vascular carrier, and the pedicles of the fascial flap were anastomosed to either the superior thyroid or facial vessels in flap prefabrication. A tissue expander was placed beneath the fascial flap to enlarge the size and reduce the thickness of the flap. The average size of the harvested fascia flap was 6.5 x 11.7 cm. After a mean interval of 21.5 weeks, the expanders were filled to a mean volume of 1,685 ml. The sizes of the prefabricated skin flaps ranged from 12 x 15 cm to 15 x 32 cm. The prefabricated skin flaps were then transferred to the recipient site as pedicled flaps for facial resurfacing. All facial soft tissue defects were successfully covered by the flaps. The donor sites were primarily closed and healed without complications. Although varied degrees of venous congestion were developed after flap transfers, the marginal necrosis only occurred in two cases. The results in follow-up showed most resurfaced faces restored natural contour and regained emotional expression. MLT is the principle for flap selection in resurfacing of the massive facial soft tissue defect. Our experience in this series of patients demonstrated that the prefabricated cervicothoracic skin flap could be a reliable alternative tool for resurfacing of massive facial soft tissue defects. (c) 2009 Wiley-Liss, Inc. Microsurgery, 2009.

A two-year prospective study of coronally positioned flap with or without acellular dermal matrix graft.

PubMed

de Queiroz Côrtes, Antonieta; Sallum, Antonio Wilson; Casati, Marcio Z; Nociti, Francisco H; Sallum, Enilson A

2006-09-01

Evaluation of the treatment of gingival recessions with coronally positioned flap with or without acellular dermal matrix allograft (ADM) after a period of 24 months. Thirteen patients with bilateral gingival recessions were included. The defects were randomly assigned to one of the treatments: coronally positioned flap plus ADM or coronally positioned flap alone. The clinical measurements were taken before the surgeries and after 6, 12 and 24 months. At baseline, the mean values for recession height were 3.46 and 3.58 mm for the defects treated with and without the graft, respectively (p>0.05). No significant differences between the groups were observed after 6 and 12 months in this parameter. However, after 24 months, the group treated with coronally positioned flap alone showed a greater recession height when compared with the group treated with ADM (1.62 and 1.15 mm, respectively--p<0.05). A significant increase in the thickness of keratinized tissue was observed in the group treated with ADM as compared with coronally positioned flap alone (p<0.05). ADM may reduce the residual gingival recession observed after 24 months in defects treated with coronally positioned flap. In addition, a greater gingival thickness may be achieved when the graft is used.

Pressure investigation of NASA leading edge vortex flaps on a 60 deg Delta wing

NASA Technical Reports Server (NTRS)

Marchman, J. F., III; Donatelli, D. A.; Terry, J. E.

1983-01-01

Pressure distributions on a 60 deg Delta Wing with NASA designed leading edge vortex flaps (LEVF) were found in order to provide more pressure data for LEVF and to help verify NASA computer codes used in designing these flaps. These flaps were intended to be optimized designs based on these computer codes. However, the pressure distributions show that the flaps wre not optimum for the size and deflection specified. A second drag-producing vortex forming over the wing indicated that the flap was too large for the specified deflection. Also, it became apparent that flap thickness has a possible effect on the reattachment location of the vortex. Research is continuing to determine proper flap size and deflection relationships that provide well-behaved flowfields and acceptable hinge-moment characteristics.

Pressure Distributions for the GA(W)-2 Airfoil with 20% Aileron, 25% Slotted Flap and 30% Fowler Flap

NASA Technical Reports Server (NTRS)

Wentz, W. H., Jr.; Fiscko, K. A.

1978-01-01

Surface pressure distributions were measured for the 13% thick GA(W)-2 airfoil section fitted with 20% aileron, 25% slotted flap and 30% Fowler flap. All tests were conducted at a Reynolds number of 2.2 x 10 to the 6th power and a Mach number of 0.13. Pressure distribution and force and moment coefficient measurements are compared with theoretical results for a number of cases. Agreement between theory and experiment is generally good for low angles of attack and small flap deflections. For high angles and large flap deflections where regions of separation are present, the theory is inadequate. Theoretical drag predictions are poor for all flap-extended cases.

Osteoradionecrosis of the olecranon: treatment by radial forearm flap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thornton, J.W.; Stevenson, T.R.; VanderKolk, C.A.

1987-12-01

Osteoradionecrosis of the olecranon is an unusual pathologic entity, treated best by debridement and wound closure using vascularized tissue. Local skin is often unavailable for flap design and transposition. The radial forearm flap can be isolated on a proximal vascular pedicle and transposed to cover the wound. In the case presented, healing was brisk and complete, allowing early elbow mobilization. Although the donor site is not easily concealed, no functional impairment results from flap elevation and all full-thickness wounds are confined to the involved extremity.

The Relevance of Hyperbaric Oxygen to Combat Medicine

DTIC Science & Technology

2001-06-01

poorly vascularized tissue, infected tissue, osteomyelitis, and irradiated tissue4𔃿. In full thickness, skin grafts and flaps, hyperbaric oxygen has...required for wound closure12ൕ" 4. The salvaging effect of hyperbaric oxygen on failing flaps and full thickness skin grafts has been demonstrated... skin grafts , Lancet 1967 Apr 22: 868-87 1. 7 McFarlane, R. M., Wermuth, R. E., The use of hyperbaric oxygen to prevent necrosis in experimental

Study on airflow characteristics of rear wing of F1 car

NASA Astrophysics Data System (ADS)

Azmi, A. R. S.; Sapit, A.; Mohammed, A. N.; Razali, M. A.; Sadikin, A.; Nordin, N.

2017-09-01

The paper aims to investigate CFD simulation is carried out to investigate the airflow along the rear wing of F1 car with Reynold number of 3 × 106 and velocity, u = 43.82204 m/s. The analysis was done using 2-D model consists of main plane and flap wing, combined together to form rear wing module. Both of the aerofoil is placed inside a box of 350mm long and 220mm height according to regulation set up by FIA. The parameters for this study is the thickness and the chord length of the flap wing aerofoil. The simulations were performed by using FLUENT solver and k-kl-omega model. The wind speed is set up to 43 m/s that is the average speed of F1 car when cornering. This study uses NACA 2408, 2412, and 2415 for the flap wing and BE50 for the main plane. Each cases being simulated with a gap between the aerofoil of 10mm and 50mm when the DRS is activated. Grid independence test and validation was conduct to make sure the result obtained is acceptable. The goal of this study is to investigate aerodynamic behavior of airflow around the rear wing as well as to see how the thickness and the chord length of flap wing influence the airflow at the rear wing. The results show that increasing in thickness of the flap wing aerofoil will decreases the downforce. The results also show that although the short flap wing generate lower downforce than the big flap wing, but the drag force can be significantly reduced as the short flap wing has more change in angle of attack when it is activated. Therefore, the type of aerofoil for the rear wing should be decided according to the circuit track so that it can be fully optimized.

Flap Gear for Airplanes : A New Scheme in Which Variation is Automatic

NASA Technical Reports Server (NTRS)

Tiltman, A Hessell

1927-01-01

A variable flap gear, which would function automatically and require no attention during flight appeared to be an attractive idea even in its early stages of development. The advantages of variable camber are described as well as the designs of these automatic flaps.

Hydroxyapatite paste Ostim, without elevation of full-thickness flaps, improves alveolar healing stimulating BMP- and VEGF-mediated signal pathways: an experimental study in humans.

PubMed

Canuto, R A; Pol, R; Martinasso, G; Muzio, G; Gallesio, G; Mozzati, M

2013-08-01

Tooth extraction is considered as the starting point of jaw atrophy via osteoclast activity stimulation. The maintenance of dental alveolar bone depends on surgery procedure and use of materials to maintain prior space favoring bone regeneration. Among substitutes used in dentistry to fill bone defects, Ostim-Pastes (Ostim) is a nanocrystalline paste tested for treatment of severe clinical conditions. This research first investigated the effect of Ostim on alveolar healing, comparing in the same healthy subjects, an Ostim-filled socket with a not-filled one. Moreover, it also proposed a new surgical protocol for the post-extractive socket treatment using the graft materials without elevation of full-thickness flaps. Fourteen patients were enrolled to bilateral maxillary or mandibular extraction that was performed without elevation of full-thickness flaps. In each patient, one socket was filled using Ostim, and the other one was allowed to undergo natural healing. No suture was carried out. Clinical and biologic parameters were screened at 1, 7, and 14 days. Obtained results evidenced that nanocrystalline hydroxyapatite supports bone regeneration, increasing the synthesis of pro-osteogenic factors as bone morphogenetics protein (BMP)-4, BMP-7, alkaline phosphatase, and osteocalcin. Moreover, filling post-extractive socket with nanocrystalline hydroxyapatite paste leads to a complete epithelialization already at 7 days after extraction, despite the fact that the teeth were extracted without elevation of full-thickness flaps . The improved epithelialization is mediated by increased vascular endothelial growth factor (VEGF) expression. No significant change was observed in inflammatory parameters, with exception of an early and transient IL-1β induction, that could trigger and improve alveolar healing. Clinical and biomolecular observations of this explorative study evidenced that nanocrystalline hydroxyapatite improves alveolar socket healing, increasing angiogenesis, epithelialization, and osteogenesis, also in absence of elevation of full-thickness flaps. © 2011 John Wiley & Sons A/S.

[Ablation on the undersurface of a LASIK flap. Instrument and method for continuous eye tracking].

PubMed

Taneri, S; Azar, D T

2007-02-01

The risk of iatrogenic keratectasia after laser in situ keratomileusis (LASIK) increases with thinner posterior stromal beds. Ablations on the undersurface of a LASIK flap could only be performed without the guidance of an eye tracker, which may lead to decentration. A new method for laser ablation with flying spot lasers on the undersurface of a LASIK flap was developed that enables the use of an active eye tracker by utilizing a novel instrument. The first clinical results are reported. Patients wishing an enhancement procedure were eligible for a modified repeat LASIK procedure if the flaps cut in the initial procedure were thick enough to perform the intended additional ablation on the undersurface leaving at least 90 microm of flap thickness behind. (1) The horizontal axis and the center of the entrance pupil were marked on the epithelial side of the flap using gentian violet dye. (2) The flap was reflected on a newly designed flap holder which had a donut-shaped black marking. (3) The eye tracker was centered on the mark visible in transparency on the flap. (4) Ablation with a flying spot Bausch & Lomb Technolas 217z laser was performed on the undersurface of the flap with a superior hinge taking into account that in astigmatic ablations the cylinder axis had to be mirrored according to the formula: axis on the undersurface=180 degrees -axis on the stromal bed. (5) The flap was repositioned. Detection of the marking on the modified flap holder and continuous tracking instead of the real pupil was possible in all of the 12 eyes treated with this technique. It may be necessary to cover the real pupil during ablation in order not to confuse the eye tracker. Ablation could be performed without decentration or loss of best spectacle-corrected visual acuity. Refractive results in minor corrections were good without nomogram adjustment. Using this novel flap holder with a marking that is tracked instead of the real pupil, centered ablations with a flying spot laser on the undersurface of a LASIK flap are feasible. Thus, the additional risk of iatrogenic keratectasia associated with stromal enhancement ablations is avoided.

Dynamic perfusion assessment during perforator flap surgery: an up-to-date

PubMed Central

MUNTEAN, MAXIMILIAN VLAD; MUNTEAN, VALENTIN; ARDELEAN, FILIP; GEORGESCU, ALEXANDRU

2015-01-01

Flap monitoring technology has progressed alongside flap design. The highly variable vascular anatomy and the complexity associated with modern perforator flaps demands dynamic, real-time, intraoperative information about the vessel location, perfusion patterns and flap physiology. Although most surgeons still assess flap perfusion and viability based solely on clinical experience, studies have shown that results may be highly variable and often misleading. Poor judgment of intraoperative perfusion leads to major complications. Employing dynamic perfusion imaging during flap reconstruction has led to a reduced complication rate, lower morbidity, shorter hospital stay, and an overall better result. With the emergence of multiple systems capable of intraoperative flap evaluation, the purpose of this article is to review the two systems that have been widely accepted and are currently used by plastic surgeons: Indocyanine green angiography (ICGA) and dynamic infrared thermography (DIRT). PMID:26609259

Histologic change of arteriovenous malformations of the face and scalp after free flap transfer.

PubMed

Tark, K C; Chung, S

2000-07-01

In three patients with long-standing vascular malformations of the face and scalp, radial forearm free flaps were transferred after a near-total excision of the lesion. All patients had typical high-flow malformations with thrill and bruit. The onset and progression of the malformations were analyzed through clinical and histologic studies. After free flap transfer, the vascular malformations were followed up grossly and histologically for between 4 and 9 years. There was no recurrence of arteriovenous malformation after free flap transfer. The portion of the residual lesion adjacent to the transferred free flap disappeared, and the remaining discoloration also vanished grossly. Histologic comparison of immediate postoperative and 4-month postoperative specimens from the margin and residual lesion using Victoria blue staining showed that the typical preoperative findings for arteriovenous malformation-an intermingling of thick-walled vessels with abundant elastic fibers and thin-walled vessels without elastic fibers-had undergone change, resulting in the disappearance of the thick-walled vessels and leaving only homogeneous, thin-walled vasculature. The highly vascularized free flap, which does not contain abnormal fistulas, impacted the histologic change of the arteriovenous malformation by blocking the vicious cycle of ischemia and anatomic replacement of disfigured skin and subcutaneous tissues.

[The cutaneous groin flap for coverage of a full-thickness abdominal wall defect].

PubMed

Doebler, O; Spierer, R

2010-08-01

A full-thickness defect of the abdominal wall is rare and may occur as a complication of extended abdominal surgery procedures. We report about a 69-year-old patient who was presented to our department with a full-thickness abdominal wall defect and a fully exposed collagen-mesh for reconstructive wound closure. 13 operations with resections of necrotic parts of the abdominal wall were performed following a complicated intraabdominal infection. After debridement and mesh explantation, closure of the remaining defect of the lower abdominal region was achieved by a cutaneous groin flap. Georg Thieme Verlag KG Stuttgart New York.

Evaluation of the cranial rectus abdominus muscle pedicle flap as a blood supply for the caudal superficial epigastric skin flap in dogs.

PubMed

Degner, D A; Walshaw, R; Arnoczky, S P; Smith, R J; Patterson, J S; Degner, L A; Hamaide, A; Rosenstein, D

1996-01-01

This study evaluates the cranial rectus abdominus muscle pedicle flap as the sole blood supply for the caudal superficial epigastric skin flap. This flap was composed of a cranially based rectus abdominus muscle pedicle flap that was attached to the caudal superficial epigastric island skin flap (including mammary glands 2 to 5) via the pudendoepigastric trunk. Selective angiography of the cranial epigastric artery in eight cadaver dogs proved that the arterial vasculature in the cranial rectus abdominus was contiguous with that in the caudal superficial epigastric skin flap. In the live dog study, three of six of the flaps failed because of venous insufficiency. Necrosis of mammary gland 2 occurred in two of six flaps. One of six flaps survived with the exception of the cranial most aspect of mammary gland 2. Angiography of the cranial epigastric artery proved that arterial blood supply to these flaps was intact. Histological evaluation of the failed flaps showed full-thickness necrosis of the skin and subcutaneous tissues, the presence of severe congestion, and venous thrombosis. Retrograde venous blood flow through the flap was inconsistent, and hence resulted in failure of this myocutaneous flap. Use of this flap for clinical wound reconstruction cannot be recommended.

Full-Thickness Reconstruction with Pedicle Flap and Diced Homologous Cartilage Over the Pericardium Complicated. Cardiac Arrest

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rees, Thomas D.

1961-01-01

Successful repair by plastic surgery of nonhealing ulceration of the chest wall, induced by radiotherapy for breast cancer, is described. Reconstruction of the chest wali defect by pedicle flap coverage was carried out. Radiation injury extended through the entire thickness of the chest wall and osteoradionecrosis of the ribs was present. Reconstruction with thoracoabdominal tube was considered to be the best technique, so a 4- by 9-in. tube pedicle was constructed. The underlying donor wound of the pedicle was covered with a split- thickness skin graft. Healing was without incident, and approximates 3 weeks after formation, the inferior end ofmore » this tube pedicle was migrated to the left epigastrium as an intermediate step. Healing was uncomplicated, and the lateral attachment of the pedicle was partially severed. Three weeks later, resection of all avascular tissue along with portions of the fourth and fifth ribs was carried out. This created a full-thickness chest wall defect measuring 4 by 8 in., with the anterior surface of the pericardial sac exposed in the wound. The end of the abdominal tube pedicle was elevated from its bed, rotated into position, and sutured to the healthy margins of the chest wall defect. The exposed subcutaneous fat of the undersurface of the pedicle was placed in juxtaposition to the pericardium. A split-thickness skin graft was cut from the skin of the left thigh and draped over the pedicle flap donor wound. All sutured wounds healed per primum and the entire skin graft survived. The inferior inset of the tube pedicle was cut free and the pedicle flap was tailored into position 6 weeks later. The patient was discharged from the hospital in good condition and engaged in normal activities. An attempt was made to provide protection for the heart beneath the pedicle inset by introduction of diced homologous cartilage grafts, just beneath the skin of the pedicle flap. This healed with the formation of a thick fibrocartilaginous structure providing some protection for the pericardial contents beneath.« less

The radix nasi island flap: a versatile musculocutaneous flap for defects of the eyelids, nose, and malar region.

PubMed

Seyhan, Tamer

2009-03-01

A versatile musculocutan flap from the radix nasi region, the radix nasi island flap, is described. The flap has an axial blood supply derived from the dorsal nasal branch of the ophthalmic artery which is anastomosed to the terminal branch of the facial artery. The flap includes the skin, subcutaneous tissue, and procerus muscle. Ten patients, aged 50 to 86 years, have been reconstructed with this flap for defects in the nose (in 4 cases), midface (in 4 cases) and lower eyelids (in 2 cases). The mean flap size was 17 x 23 mm (range: 15 x 20 to 20 x 27 mm). All flaps fully survived. Additional complications and morbidity were not observed. The donor sites were closed a primarily closure in all cases. Follow-up ranged from 3 to 12 months (mean: 8.2 months). The radix nasi flap is a safe flap, has minimal donor site morbidity, and is especially suited for nasal and midface reconstruction in terms of attaining a suitable color and thickness.

A study of the variable impedance surface concept as a means for reducing noise from jet interaction with deployed lift-augmenting flaps

NASA Technical Reports Server (NTRS)

Hayden, R. E.; Kadman, Y.; Chanaud, R. C.

1972-01-01

The feasibility of quieting the externally-blown-flap (EBF) noise sources which are due to interaction of jet exhaust flow with deployed flaps was demonstrated on a 1/15-scale 3-flap EBF model. Sound field characteristics were measured and noise reduction fundamentals were reviewed in terms of source models. Test of the 1/15-scale model showed broadband noise reductions of up to 20 dB resulting from combination of variable impedance flap treatment and mesh grids placed in the jet flow upstream of the flaps. Steady-state lift, drag, and pitching moment were measured with and without noise reduction treatment.

Single perforator greater saphenous neuro-veno-fasciocutaneous propeller flaps for lower extremity reconstructions.

PubMed

Zhong, Wanrun; Lu, Shengdi; Wang, Chunyang; Wen, Gen; Han, Pei; Chai, Yimin

2017-07-01

The lack of soft tissue that is available for medial leg and foot defect reconstructions presents a challenge for plastic surgeons. The saphenous neurofasciocutaneous perforator flap application presents an effective alternative to local flap transfers. However, the venous flow and pedicle twisting problems are still disputed. Here, we present our experiences with modified cutaneous pedicles with a single perforator pedicle, which improves the venous flow and the pedicle twisting problem. This study was conducted from June 2007 through September 2011, and a total of 15 patients with lower medial leg and foot defects were included. There were 11 men and four women. An asymmetric 'propeller' flap was planned around a perforator that was adjacent to the defects, which was preoperatively confirmed by Doppler. The perforator was sufficiently dissociated to allow for the flap to be turned towards the defects. We preserved some distal skin and subcutaneous tissue from the short side of the 'propeller' to cover some donor site regions, and other regions were covered with split thickness skin grafts. The follow-up period ranged from 3 to 12 months. An infection occurred in one case. Partial flap necrosis was noted in two cases. The other 12 flaps completely survived and matched the recipient sites with regard to colour, texture and thickness. The single perforator greater saphenous neuro-veno-fasciocutaneous propeller flap is an effective solution for medial leg and foot defects, and it has a large rotation arc and a satisfactory aesthetic result. © 2015 Royal Australasian College of Surgeons.

Analysis of non-linear aeroelastic response of a supersonic thick fin with plunging, pinching and flapping free-plays

NASA Astrophysics Data System (ADS)

Firouz-Abadi, R. D.; Alavi, S. M.; Salarieh, H.

2013-07-01

The flutter of a 3-D rigid fin with double-wedge section and free-play in flapping, plunging and pitching degrees-of-freedom operating in supersonic and hypersonic flight speed regimes have been considered. Aerodynamic model is obtained by local usage of the piston theory behind the shock and expansion analysis, and structural model is obtained based on Lagrange equation of motion. Such model presents fast, accurate algorithm for studying the aeroelastic behavior of the thick supersonic fin in time domain. Dynamic behavior of the fin is considered over large number of parameters that characterize the aeroelastic system. Results show that the free-play in the pitching, plunging and flapping degrees-of-freedom has significant effects on the oscillation exhibited by the aeroelastic system in the supersonic/hypersonic flight speed regimes. The simulations also show that the aeroelastic system behavior is greatly affected by some parameters, such as the Mach number, thickness, angle of attack, hinge position and sweep angle.

Large-Scale Wind-Tunnel Tests of an Airplane Model with an Unswept, Aspect-Ratio-10 Wing, Two Propellers, and Blowing Flaps

NASA Technical Reports Server (NTRS)

Griffin, Roy N., Jr.; Holzhauser, Curt A.; Weiberg, James A.

1958-01-01

An investigation was made to determine the lifting effectiveness and flow requirements of blowing over the trailing-edge flaps and ailerons on a large-scale model of a twin-engine, propeller-driven airplane having a high-aspect-ratio, thick, straight wing. With sufficient blowing jet momentum to prevent flow separation on the flap, the lift increment increased for flap deflections up to 80 deg (the maximum tested). This lift increment also increased with increasing propeller thrust coefficient. The blowing jet momentum coefficient required for attached flow on the flaps was not significantly affected by thrust coefficient, angle of attack, or blowing nozzle height.

Scalp Reconstruction With Free Latissimus Dorsi Flap in a Patient With Giant Cutis Verticis Gyrata.

PubMed

Mutlu, Ozay Ozkaya; Colak, Ozlem; Canli, Mert; Akcay, Ayberk

2016-09-01

Cutis verticis gyrata is a rare skin disorder characterized by formation of thick skin folds and grooves. Because of the risk of malignant transformation, these lesions must be surgically excised. In this study, the authors aimed to present a successful reconstruction of scalp with free latissimus dorsi musculocutaneous flap after total excision of giant cerebriform intradermal nevus that causes cutis verticis gyrata. An 18-year-old male patient attended to our clinic with a large tumor that covers almost 80% of his scalp. Lesion is diagnosed as cerebriform intradermal nevus. Excision of the tumor and scalp reconstruction with free latissimus dorsi musculocutaneous flap is planned and the patient is operated. Free tissue transfer is one of the best choices for full thickness defects that covers 80% of scalp with its excellent reconstructive and aesthetical results. Reconstruction with free flaps reduces the number of operations necessary to cover the defect unlike serial tissue expansion or staged excision methods. Free flaps are also a good alternative when the patient has not enough hair-bearing tissue to expand. Low donor site morbidity also makes free latissimus dorsi musculocutaneous flaps excellent choice. Cerebriform intradermal nevus is one of the most common causes of cutis verticis gyrata and has an importance due to the current risk of malign transformation. Latissimus dorsi musculocutaneous free flap is a reliable and aesthetically acceptable reconstruction option in the patients of giant cutis verticis gyrata due to sufficient pedicle length, reliable vascularized tissue volume, and large surface area.

Resurfacing the Penis of Complex Hypospadias Repair ("Hypospadias Cripples").

PubMed

Fam, Mina M; Hanna, Moneer K

2017-03-01

After the creation of a neourethra in a "hypospadias cripple," resurfacing the penis with healthy skin is a significant challenge because local tissue is often scarred and unusable. We reviewed our experience with various strategies to resurface the penis of hypospadias cripples. We retrospectively reviewed the records of 215 patients referred after multiple unsuccessful hypospadias repairs from 1981 to 2014. In 130 of 215 patients we performed resurfacing using local penile flaps using various techniques, including Byars flaps, Z-plasty or double Z-plasty, or a dorsal relaxing incision. Of the 215 patients 85 did not have adequate healthy local penile skin to resurface the penis after urethroplasty. Scrotal skin was used to resurface the penis in 54 patients, 6 underwent tissue expansion of the dorsal penile skin during a 12 to 16-week period prior to penile resurfacing, 23 underwent full-thickness skin grafting and another 4 received a split-thickness skin graft. Of the 56 patients who underwent fasciomyocutaneous rotational flaps, tissue expansion or a combination of both approaches 54 (96.4%) finally had a successful outcome. All 6 patients who underwent tissue expansion had a successful outcome without complications and were reported on previously. All 23 full-thickness skin grafts took with excellent results. All 4 patients who underwent fenestrated split-thickness skin grafting had 100% graft take but secondary contraction and ulceration were associated with sexual activity. In our experience scrotal skin flaps, tissue expansion of the dorsal penile skin and full-thickness skin grafts serve as reliable approaches in resurfacing the penis in almost any hypospadias cripple lacking healthy local skin. Copyright © 2017 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Static internal performance of single-expansion-ramp nozzles with various combinations of internal geometric parameters

NASA Technical Reports Server (NTRS)

Re, R. J.; Leavitt, L. D.

1984-01-01

The effects of five geometric design parameters on the internal performance of single-expansion-ramp nozzles were investigated at nozzle pressure ratios up to 10 in the static-test facility of the Langley 16-Foot Transonic Tunnel. The geometric variables on the expansion-ramp surface of the upper flap consisted of ramp chordal angle, ramp length, and initial ramp angle. On the lower flap, the geometric variables consisted of flap angle and flap length. Both internal performance and static-pressure distributions on the centerlines of the upper and lower flaps were obtained for all 43 nozzle configurations tested.

The Lymphatic Response to Injury with Soft-Tissue Reconstruction in High-Energy Open Tibial Fractures of the Lower Extremity.

PubMed

van Zanten, Malou C; Mistry, Raakhi M; Suami, Hiroo; Campbell-Lloyd, Andrew; Finkemeyer, James P; Piller, Neil B; Caplash, Yugesh

2017-02-01

Severe compound tibial fractures are associated with extensive soft-tissue damage, resulting in disruption of lymphatic pathways that leave the patient at risk of developing chronic lymphedema. There are limited data on lymphatic response following lower limb trauma. Indocyanine green fluorescence lymphography is a novel, real-time imaging technique for superficial lymphatic mapping. The authors used this technique to image the superficial lymphatic vessels of the lower limbs in patients with severe compound tibial fracture. Baseline demographics and clinical and operative details were recorded in a prospective cohort of 17 patients who had undergone bone and soft-tissue reconstruction after severe compound tibial fracture between 2009 and 2014. Normal lymphatic images were obtained from the patients' noninjured limbs as a control. In this way, the authors investigated any changes to the normal anatomy of the lymphatic system in the affected limbs. Of the 17 patients, eight had free muscle flaps with split-thickness skin grafting, one had a free fasciocutaneous flap, one had a full-thickness skin graft, six had local fasciocutaneous flaps, and one had a pedicled gastrocnemius flap. None of the free flaps demonstrated any functional lymphatic vessels; the fasciocutaneous flaps and the skin graft demonstrated impaired lymphatic vessel function and dermal backflow pattern similar to that in lymphedema. Local flaps demonstrated lymphatic blockage at the scar edge. Severe compound fractures and the associated soft-tissue injury can result in significant lymphatic disruption and an increased risk for the development of chronic lymphedema.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miyamoto, Y.; Hattori, T.; Niimoto, M.

In 15 patients chest walls were excised because of recurrent breast cancer, radiation ulcer, or rib tumor. In most cases the full-thickness defect of the chest wall was about 10 x 10 cm. Reconstruction was performed using only a rectus abdominis musculocutaneous flap. No patient developed circulation problems in the flap or severe flail chest, and we had successful results in all our cases. These results show that the rectus abdominis musculocutaneous flap is quite effective and safe to use in the reconstruction of chest wall defects.

Free-style free flaps.

PubMed

Wei, Fu-Chan; Mardini, Samir

2004-09-15

Free-tissue transfer has become the accepted standard for reconstruction of complex defects. With the growth of this field, anatomic studies and clinical work have added many flaps to the armamentarium of the microvascular surgeon. Further advancements and experience with techniques of perforator flap surgery have allowed for the harvest of flaps in a free-style manner, where a flap is harvested based only on the preoperative knowledge of Doppler signals present in a specific region. Between June of 2002 and September of 2003, 13 free-style free flaps were harvested from the region of the thigh. All patients presented with an oral or pharyngeal cancer and underwent resection and immediate reconstruction of these flaps. All flaps were cutaneous and were harvested in a suprafascial plane. The average size of the flaps was 108 cm2 (range, 36 to 187 cm2), and the average length of the vascular pedicle was 10 cm (range, 9 to 12 cm). All flaps were successful in achieving wound coverage and functional outcomes without any vascular compromise necessitating re-exploration. Free-style free flaps have become a clinical reality. The concepts and techniques used to harvest a free-style free flap will aid in dealing with anatomic variations that are encountered during conventional flap harvest. Future trends in flap selection will focus mainly on choosing tissue with appropriate texture, thickness, and pliability to match requirements at the recipient site while minimizing donor-site morbidity.

Prefabricated bone flap: an experimental study comparing deep-frozen and lyophilized-demineralized allogenic bones and tissue expression of transforming growth factor β.

PubMed

Rodrigues, Leandro; dos Reis, Luciene Machado; Denadai, Rafael; Raposo-Amaral, Cassio Eduardo; Alonso, Nivaldo; Ferreira, Marcus Castro; Jorgetti, Vanda

2013-11-01

Extensive bone defects are still a challenge for reconstructive surgery. Allogenic bones can be an alternative with no donor area morbidity and unlimited amount of tissue. Better results can be achieved after allogenic bone preparation and adding a vascular supply, which can be done along with flap prefabrication. The purpose of this study was to evaluate demineralized/lyophilized and deep-frozen allogenic bones used for flap prefabrication and the tissue expression of transforming growth factor β (TGF-β) in these bone fragments. Fifty-six Wistar rat bone diaphyses were prepared and distributed in 4 groups: demineralized/lyophilized (experimental group 1 and control group 2) and deep freezing (experimental group 3 and control group 4). Two bone segments (one of each group) were implanted in rats to prefabricate flaps using superficial epigastric vessels (experimental groups) or only transferred as grafts (control groups). These fragments remained in their respective inguinal regions until the death that occurred at 2, 4, and 6 weeks after the operation. Semiquantitative histologic (tetracycline marking, cortical resorption, number of giant cells, and vascularization) and histomorphometrical quantitative (osteoid thickness, cortical thickness, and fibrosis thickness) analyses were performed. Transforming growth factor β immunohistochemistry staining was also performed. Group 1 fragments presented an osteoid matrix on their external surface in all periods. Cartilage formation and mineralization areas were also noticed. These findings were not observed in group 3 fragments. Group 1 had more mineralization and double tetracycline marks, which were almost not seen in group 3. Cortical resorption and the number of giant cells were greater in group 3 in all periods. Vascularization and fibrosis thickness were similar in both experimental groups. Group 1 had more intense TGF-β staining within 2 weeks of study. Nevertheless, from 4 weeks onward, group 3 presented statistically significant stronger staining. Although there are some differences between the preparation methods of allogenic bone, it is possible to prefabricate flaps with demineralized/lyophilized and deep-frozen bones.

Wound complications and clinical results of electrocautery versus a scalpel to create a cutaneous flap in thyroidectomy: a prospective randomized trial.

PubMed

Uludag, Mehmet; Yetkin, Gurkan; Ozel, Alper; Ozguven, M Banu Yilmaz; Yener, Senay; Isgor, Adnan

2011-08-01

The use of electrocautery for tissue dissection is becoming increasingly popular, despite the associated risk of poor wound healing and excessive scarring. We conducted this study to compare the wound complications and early and late clinical results resulting from electrocautery versus the scalpel to create a cutaneous flap during thyroidectomy. The subjects of this study were 100 patients, randomized prospectively to either a scalpel group (group S, n = 50) or an electrocautery group (group E, n = 50). Thickness of tissue damage, postoperative thickness of the flap, discomfort in the neck 7 days after surgery, and hypoesthesia and paresthesia in the neck 3 months after surgery were significantly higher in group E than in group S. There were no significant differences in overall postoperative wound complications, postoperative pain, satisfaction with the cosmetic result, or overall outcome of the operation between the groups. Although the incidence of seroma was higher in group E (20%) than in group S (8%), the difference was not significant. Although electrocautery was associated with increased histological tissue damage, postoperative flap edema, discomfort, and other complications in the early stage, the clinical and cosmetic results of flaps made using electrocautery or a scalpel were similar and satisfactory 6 months after surgery.

Combined V-Y Fasciocutaneous Advancement and Gluteus Maximus Muscle Rotational Flaps for Treating Sacral Sores

PubMed Central

Choi, Eun Jeong; Moon, Suk Ho; Lee, Yoon Jae

2016-01-01

The sacral area is the most common site of pressure sore in bed-ridden patients. Though many treatment methods have been proposed, a musculocutaneous flap using the gluteus muscles or a fasciocutaneous flap is the most popular surgical option. Here, we propose a new method that combines the benefits of these 2 methods: combined V-Y fasciocutaneous advancement and gluteus maximus muscle rotational flaps. A retrospective review was performed for 13 patients who underwent this new procedure from March 2011 to December 2013. Patients' age, sex, accompanying diseases, follow-up duration, surgical details, complications, and recurrence were documented. Computed tomography was performed postoperatively at 2 to 4 weeks and again at 4 to 6 months to identify the thickness and volume of the rotational muscle portion. After surgery, all patients healed within 1 month; 3 patients experienced minor complications. The average follow-up period was 13.6 months, during which time 1 patient had a recurrence (recurrence rate, 7.7%). Average thickness of the rotated muscle was 9.43 mm at 2 to 4 weeks postoperatively and 9.22 mm at 4 to 6 months postoperatively (p = 0.087). Muscle thickness had not decreased, and muscle volume was relatively maintained. This modified method is relatively simple and easy for reconstructing sacral sores, provides sufficient padding, and has little muscle donor-site morbidity. PMID:27366755

Delayed grafting for banked skin graft in lymph node flap transfer.

PubMed

Ciudad, Pedro; Date, Shivprasad; Orfaniotis, Georgios; Dower, Rory; Nicoli, Fabio; Maruccia, Michele; Lin, Shu-Ping; Chuang, Chu-Yi; Chuang, Tsan-Yu; Wang, Gou-Jen; Chen, Hung-Chi

2017-02-01

Over the last decade, lymph node flap (LNF) transfer has turned out to be an effective method in the management of lymphoedema of extremities. Most of the time, the pockets created for LNF cannot be closed primarily and need to be resurfaced with split thickness skin grafts. Partial graft loss was frequently noted in these cases. The need to prevent graft loss on these iatrogenic wounds made us explore the possibility of attempting delayed skin grafting. We have herein reported our experience with delayed grafting with autologous banked split skin grafts in cases of LNF transfer for lymphoedema of the extremities. Ten patients with International Society of Lymphology stage II-III lymphoedema of upper or lower extremity were included in this study over an 8-month period. All patients were thoroughly evaluated and subjected to lymph node flap transfer. The split skin graft was harvested and banked at the donor site, avoiding immediate resurfacing over the flap. The same was carried out in an aseptic manner as a bedside procedure after confirming flap viability and allowing flap swelling to subside. Patients were followed up to evaluate long-term outcomes. Flap survival was 100%. Successful delayed skin grafting was done between the 4th and 6th post-operative day as a bedside procedure under local anaesthesia. The split thickness skin grafts (STSG) takes more than 97%. One patient needed additional medications during the bedside procedure. All patients had minimal post-operative pain and skin graft requirement. The patients were also reported to be satisfied with the final aesthetic results. There were no complications related to either the skin grafts or donor sites during the entire period of follow-up. Delayed split skin grafting is a reliable method of resurfacing lymph node flaps and has been shown to reduce the possibility of flap complications as well as the operative time and costs. © 2016 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Wind-Tunnel Investigation of the Effect of Angle of Attack and Flapping-Hinge Offset on Periodic Bending Moments and Flapping of a Small Rotor

NASA Technical Reports Server (NTRS)

McCarty, John Locke; Brooks, George W.; Maglieri, Domenic J.

1959-01-01

A two-blade rotor having a diameter of 4 feet and a solidity of 0.037 was tested in the Langley 300-MPH 7- by 10-foot tunnel to obtain information on the effect of certain rotor variables on the blade periodic bending moments and flapping angles during the various stages of transformation between the helicopter and autogiro configuration. Variables studied included collective pitch angle, flapping-hinge offset, rotor angle of attack, and tip-speed ratio. The results show that the blade periodic bending moments generally increase with tip-speed ratio up into the transition region, diminish over a certain range of tip-speed ratio, and increase again at higher tip-speed ratios. Above the transition region, the bending moments increase with collective pitch angle and rotor angle of attack. The absence of a flapping hinge results in a significant amplification of the periodic bending moments, the magnitudes of which increase with tip-speed ratio. When the flapping hinge is used, an increase in flapping-hinge offset results in reduced period bending moments. The aforementioned trends exhibited by the bending moments for changes in the variables are essentially duplicated by the periodic flapping motions. The existence of substantial amounts of blade stall increased both the periodic bending moments and the flapping angles. Harmonic analysis of the bending moments shows significant contributions of the higher harmonics, particularly in the transition region.

Cost-effectiveness of Early Division of the Forehead Flap Pedicle.

PubMed

Calloway, Hollin E; Moubayed, Sami P; Most, Sam P

2017-09-01

The paramedian forehead flap is considered the gold standard procedure to optimally reconstruct major defects of the nose, but this procedure generally requires 2 stages, where the flap pedicle is divided 3 weeks following the initial surgery to ensure adequate revascularization of the flap from the surrounding recipient tissue bed, which can cost a patient time out of work or away from normal social habits. It has previously been shown that the pedicle may be safely divided after 2 weeks in select patients where revascularization from the recipient bed was confirmed using intraoperative laser fluorescence angiography to potentially save the patient time and money. To demonstrate the cost-effectiveness of takedown of the paramedian forehead flap pedicle after 2 weeks using angiography with indocyanine green (ICG). Retrospective cohort study of all patients who underwent 2-week division of the forehead flap after nasal reconstruction. Patient, tumor, defect, and outcomes data were collected. Cost-minimization analysis was performed by comparing the overall costs of 2-week takedown with angiography to a hypothetical patient undergoing 3-week takedown without angiography. Two-week division of the forehead flap after nasal reconstruction. Cost-minimization analysis performed by calculating the total variable costs for a patient in our cohort vs costs to a theoretical patient for whom angiography was not performed and the pedicle was divided at the 3-week mark. A total of 22 patients were included (mean [SD] age, 70.3 [10.0] years; 8 women [36.4%] and 14 men [63.6%]). The selection criteria for 2-week division of the pedicle are a wound bed with at least 50% vascularized tissue present, partial-thickness defects, and absence of nicotine use. All were divided at the 2-week mark with no instances of flap necrosis. One patient had a squamous eccrine carcinoma histology before reconstruction, all other patients had basal cell carcinoma, squamous cell carcinoma, and melanoma. Cost-minimization analysis showed that the use of angiography with ICG results in cost savings of $177 per patient on average. Two-week takedown of select paramedian forehead flap patients can be performed safely with verification using angiography with ICG. Although this technology inherently adds cost, it is cost-effective, saving a total of $177 per patient. NA.

Experimental studies of flow separation and stalling on two-dimensional airfoils at low speeds. Phase 2: Studies with Fowler flap extended

NASA Technical Reports Server (NTRS)

Seetharam, H. C.; Wentz, W. H., Jr.

1975-01-01

Results were given on experimental studies of flow separation and stalling on a two-dimensional GA(W)-1 17 percent thick airfoil with an extended Fowler flap. Experimental velocity profiles obtained from a five tube probe survey with optimum flap gap and overlap setting (flap at 40 deg) are shown at various stations above, below, and behind the airfoil/flap combination for various angles of attack. The typical zones of steady flow, intermittent turbulence, and large scale turbulence were obtained from a hot wire anemometer survey and are depicted graphically for an angle of attack of 12.5 deg. Local skin friction distributions were obtained and are given for various angles of attack. Computer plots of the boundary layer profiles are shown for the case of the flap at 40 deg. Static pressure contours are also given. A GA(W)-2 section model was fabricated with 30 percent Fowler flaps and with pressure tabs.

Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK.

PubMed

Xia, Li-Kun; Yu, Jie; Chai, Guang-Rui; Wang, Dang; Li, Yang

2015-01-01

To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P<0.01). The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P<0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome treated eyes at postoperative 1, 3mo (P<0.01). Both the femtosecond laser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer TBUT.

Comparison of the femtosecond laser and mechanical microkeratome for flap cutting in LASIK

PubMed Central

Xia, Li-Kun; Yu, Jie; Chai, Guang-Rui; Wang, Dang; Li, Yang

2015-01-01

AIM To compare refractive results, higher-order aberrations (HOAs), contrast sensitivity and dry eye after laser in situ keratomileusis (LASIK) performed with a femtosecond laser versus a mechanical microkeratome for myopia and astigmatism. METHODS In this prospective, non-randomized study, 120 eyes with myopia received a LASIK surgery with the VisuMax femtosecond laser for flap cutting, and 120 eyes received a conventional LASIK surgery with a mechanical microkeratome. Flap thickness, visual acuity, manifest refraction, contrast sensitivity function (CSF) curves, HOAs and dry-eye were measured at 1wk; 1, 3, 6mo after surgery. RESULTS At 6mo postoperatively, the mean central flap thickness in femtosecond laser procedure was 113.05±5.89 µm (attempted thickness 110 µm), and 148.36±21.24 µm (attempted thickness 140 µm) in mechanical microkeratome procedure. An uncorrected distance visual acuity (UDVA) of 4.9 or better was obtained in more than 98% of eyes treated by both methods, a gain in logMAR lines of corrected distance visual acuity (CDVA) occurred in more than 70% of eyes treated by both methods, and no eye lost ≥1 lines of CDVA in both groups. The difference of the mean UDVA and CDVA between two groups at any time post-surgery were not statistically significant (P>0.05). The postoperative changes of spherical equivalent occurred markedly during the first month in both groups. The total root mean square values of HOAs and spherical aberrations in the femtosecond treated eyes were markedly less than those in the microkeratome treated eyes during 6mo visit after surgery (P<0.01). The CSF values of the femtosecond treated eyes were also higher than those of the microkeratome treated eyes at all space frequency (P<0.01). The mean ocular surface disease index scores in both groups were increased at 1wk, and recovered to preoperative level at 1mo after surgery. The mean tear breakup time (TBUT) of the femtosecond treated eyes were markedly longer than those of the microkeratome treated eyes at postoperative 1, 3mo (P<0.01). CONCLUSION Both the femtosecond laser and the mechanical microkeratome for LASIK flap cutting are safe and effective to correct myopia, with no statistically significant difference in the UDVA, CDVA during 6mo follow-up. Refractive results remained stable after 1mo post-operation for both groups. The femtosecond laser may have advantages over the microkeratome in the flap thickness predictability, fewer induced HOAs, better CSF, and longer TBUT. PMID:26309880

Magnetic Configurations of the Tilted Current Sheets and Dynamics of Their Flapping in Magnetotail

NASA Astrophysics Data System (ADS)

Shen, C.; Rong, Z. J.; Li, X.; Dunlop, M.; Liu, Z. X.; Malova, H. V.; Lucek, E.; Carr, C.

2009-04-01

Based on multiple spacecraft measurements, the geometrical structures of tilted current sheet and tail flapping waves have been analyzed and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1) The magnetic field lines (MFLs) are generally plane curves and the osculating planes in which the MFLs lie are about vertical to the magnetic equatorial plane, while the tilted current sheet may lean severely to the dawn or dusk side. (2) The tilted current sheet may become very thin, its half thickness is generally much less than the minimum radius of the curvature of the MFLs. (3) In the neutral sheet, the field-aligned current density becomes very large and has a maximum value at the center of the current sheet. (4) In some cases, the current density is a bifurcated one, and the two humps of the current density often superpose two peaks in the gradient of magnetic strength, indicating that the magnetic gradient drift current is possibly responsible for the formation of the two humps of the current density in some tilted current sheets. Tilted current sheets often appear along with tail thick current sheet flapping waves. It is found that, in the tail flapping current sheets, the minimum curvature radius of the MFLs in the current sheet is rather large with values around 1RE, while the neutral sheet may be very thin, with its half thickness being several tenths ofRE. During the flapping waves, the current sheet is tilted substantially, and the maximum tilt angle is generally larger than 45

Changes in Keratocyte Density and Visual Function Five Years After Laser In Situ Keratomileusis: Femtosecond Laser Versus Mechanical Microkeratome.

PubMed

McLaren, Jay W; Bourne, William M; Maguire, Leo J; Patel, Sanjay V

2015-07-01

To determine the effects of keratocyte loss on optical properties and vision after laser in situ keratomileusis (LASIK) with the flap created with a femtosecond laser or a mechanical microkeratome. Randomized clinical paired-eye study. Both eyes of 21 patients received LASIK for myopia or myopic astigmatism. One eye of each patient was randomized by ocular dominance to flap creation with a femtosecond laser and the other eye to flap creation with a mechanical microkeratome. Before LASIK and at 1, 3, and 6 months and 1, 3, and 5 years after LASIK, keratocyte density was measured using confocal microscopy, and high-contrast visual acuity and anterior corneal wavefront aberrations were measured by standard methods. At each visit, all variables were compared between methods of creating the flap and to the same variable before treatment using paired tests with Bonferroni correction for multiple comparisons. Keratocyte density in the flap decreased by 20% during the first year after LASIK and remained low through 5 years (P < .001). High-order wavefront aberrations increased and uncorrected visual acuity improved immediately after surgery, but these variables did not change further to 5 years. There were no differences in any variables between treatments. A sustained reduction in keratocyte density does not affect vision or optical properties of the cornea through 5 years after LASIK. The method of creating a LASIK flap does not influence the changes in keratocyte density in the flap. Copyright © 2015 Elsevier Inc. All rights reserved.

[Comparison of pedicle and free tissue transfers in the German DRG system].

PubMed

Lotter, O; Stahl, S; Hohenstein, C; Schaller, H-E; Jaminet, P

2011-12-01

Diagnosis-Related Groups (DRGs) are a patient classification system grouping related types of patients to the resources they have consumed. In this analysis, we compared pedicle and free flaps in plastic and reconstructive surgery in the actual German DRG system. After grouping common flaps while systematically modifying the diagnosis, the operative procedure(s), and the receptor site, reimbursement and thresholds of length of stay were identified. The mean value of the average length of stay was higher in free flaps as compared to pedicle flaps (15 vs. 9 days) and the mean reimbursement in free flaps was almost twice as high as in pedicle flaps (8 936 € vs. 4 582 €). Regarding the diagnosis, third-grade open fractures in pedicle flaps and full-thickness burns in free flaps are in the vanguard of reimbursement. Higher DRG conformity is generally found with free flaps. Different possibilities in coding the procedures and the strong dependence on the underlying diagnosis lead to variations of remuneration and length of stay, which are not explainable and sometimes even seem paradoxical. Furthermore, mixed calculation creates DRGs that lose the ability to describe the real effort. © Georg Thieme Verlag KG Stuttgart · New York.

Unit Advancement Flap for Lower Lip Reconstruction.

PubMed

Ogino, Akihiro; Onishi, Kiyoshi; Okada, Emi; Nakamichi, Miho

2018-05-01

Lower lip reconstruction requires consideration of esthetic and functional outcome in selecting a surgical procedure, and reconstruction with local tissue is useful. The authors reconstructed full-thickness defects with a unit advancement flap. Reconstruction was performed using this method in 4 patients with lower lip squamous cell carcinoma in whom tumor resection with preservation of the mouth angle was possible. The lower lip resection width was 30 to 45 mm, accounting for 50% to 68% of the entire width of the lower lip. The flap was prepared by lateral extension from above the mental unit and matched with the potential wrinkle line of the lower lip in order to design a unit morphology surrounded by the anterior margin of the depressor labii inferioris muscle. It was elevated as a full-thickness flap composed of the orbicularis oris muscle, skin, and mucosa of the residual lower lip from the bilateral sides, and advanced to the defect. Flap transfer was adjusted by small triangular resection of the skin on the lateral side of the mental unit. The postoperative scar was inconspicuous in all patients and there was no impairment of the mouth opening-closing or articulation functions. This was a relatively simple surgical procedure. A blood supply of the flap was stable, and continuity of the orbicularis oris muscle was reconstructed by transferred the residual lower lip advancement flap from the bilateral sides. The postoperative mouth opening-closing function was sufficient, and dentures could be placed from an early phase in elderly patients. The postoperative scar was consistent with the lip unit morphology, being esthetically superior. This procedure may be applicable for reconstruction of defects approximately 1/3 to 2/3 the width of the lower lip where the mouth angle is preserved.

Suprascarpal fat pad thickness may predict venous drainage patterns in abdominal wall flaps.

PubMed

Bast, John; Pitcher, Austin A; Small, Kevin; Otterburn, David M

2016-02-01

Abdominal wall flaps are routinely used in reconstructive procedures. In some patients inadequate venous drainage from the deep vein may cause fat necrosis or flap failure. Occasionally the superficial inferior epigastric vessels (SIEV) are of sufficient size to allow for microvascular revascularization. This study looked at the ratio of the sub- and suprascarpal fat layers, the number of deep system perforators, and SIEV diameter to determine any correlation of the fat topography and SIEV. 50 abdominal/pelvic CT angiograms (100 hemiabdomens) were examined in women aged 34-70 years for number of perforators, SIEV diameter, and fat pad thickness above and below Scarpa's fascia. Data was analyzed using multivariate model. The average suprascarpal and subscarpal layers were 18.6 ± 11.5 mm and 6.2 ± 7.2 mm thick, respectively. The average SIEV diameter was 2.06 ± 0.81 mm and the average number of perforators was 2.09 ± 1.03 per hemiabdomen. Hemiabdomens with suprascarpal thickness>23 mm had greater SIEV diameter [2.69 mm vs. 1.8 mm (P < 0.0001)] The fat layer thickness did not correlate with the number of perforators. Neither subscarpal fat thickness nor suprascarpal-to-subscarpal fat layer thickness correlated significantly with SIEV caliber or number of perforators in multivariate model. Suprascarpal fat pad thicker than 23 mm had larger SIEVs irrespective of the number of deep system perforators. This may indicate a cohort of patients at risk of venous congestion from poor venous drainage if only the deep system is revascularized. We recommend harvesting the SIEV in patients with suprascarpal fat pad >23 mm to aid in superficial drainage. © 2015 Wiley Periodicals, Inc.

The Postauricular Helix-based Adipodermal-pedicle Turnover (PHAT) Flap: An Original Single-Stage Technique for Antihelix and Scapha Reconstruction.

PubMed

Beustes-Stefanelli, Matthieu; O'Toole, Greg; Schertenleib, Pierre

2016-01-01

In reconstructing anterior defects of the ear, postauricular flaps represent a popular option. The pedicle of such transauricular flaps can be superior, inferior, medial, or lateral. The postauricular helix-based adipodermal-pedicle turnover (PHAT) flap is an original single-stage transauricular technique for defects of the antihelix and scapha. Its skin paddle is on the posterior aspect of the ear. Its lateral de-epithelialized pedicle in front of the helix allows for it to easily reach peripheral anterior defects. In cases in which the underlying cartilage is involved, the extended PHAT (ePHAT) flap allows for restoring the contours of the ear without a cartilage graft. Between 2009 and 2011, a PHAT flap was used in 5 cases of defects of the antihelix or the scapha after tumor resection, 3 of which are in an extended version (ePHAT flap). There were no complications and a satisfactory aesthetic result was achieved in all cases. The PHAT flap is an original single-stage procedure for anterior auricular defects located on the antihelix or scapha. The single-layer PHAT flap is indicated in purely skin defect. The triple-layer ePHAT flap includes two subcutaneous extensions which increase its thickness and is indicated to restore the ear contours when cartilage has been removed.

Levator alae nasi muscle V-Y island flap for nasal tip reconstruction.

PubMed

La Padula, Simone; Abbate, Vincenzo; Di Monta, Gianluca; Schonauer, Fabrizio

2017-03-01

Nasal tip reconstruction can be very challenging. It requires close attention to skin texture, colour and thickness matching, with the respect of the nasal aesthetic units and symmetry. Flaps are usually preferred to skin grafts where possible. Based on different donor areas, various flaps have been described for reconstruction of this region. Here we present a new V-Y myocutaneous island flap based on the levator alae nasi muscle (LAN muscle) blood supply. This flap may represent an alternative to the nasalis myocutaneous sliding V-Y flap previously described by Rybka. As its pivot point it is located more cranially than the nasalis flap, and it can advance more medially than the Rybka flap, with the possibility of covering larger defects of the nasal tip area, up to 1.8 cm in diameter. Over the past 5 years, 24 patients received nasal tip reconstruction with this flap following the resection of basal cell carcinomas. Good tip projection was maintained, and the aesthetic outcome was satisfactory, with well healed scars. We recommend this technique as an alternative to other flaps for nasal tip defects, especially if paramedian. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Pectoralis Major Musculocutaneous Flap With a Midline Sternal Skin Paddle for Head and Neck Reconstruction: A New Design.

PubMed

Oh, Jeongseok; Ahn, Hee Chang; Youn, Seungki; Tae, Kyung

2018-05-14

The pectoralis major musculocutaneous (PMMC) flap is a classic flap for head and neck reconstruction, relatively unpopular with the advancement of microsurgery and free flaps. The classic parasternal paddle design provided a thick flap with a small rotation arch leaving objectionable scarring. Our new symmetric midsternal design overcomes these problems. Chart review was done from the years 2000 to 2017. Flap skin paddle was placed symmetrically on both sides of the midsternal line. The pectoralis major (PM) muscle and aponeurosis were attached in the lateral half of the skin paddle. Most of PM muscle was elevated with the thoracoacromial vessel and dissected to the main trunk, where the PM muscle was cut and used for bulk. The flap was transferred to the neck and lower mandibular area. The flap was inset either supraclavicularly, covering the anterior neck, or subclavicularly, for intraoral/maxillary defects. Eight patients underwent head and neck reconstruction using the new design of PMMC flap between the years 2000 and 2017. The etiologies of the defect were radiation necrosis in 3 patients, repair of cutaneous fistulas in 3, recurrent hypopharyngeal cancer in 1, and recurrent tongue cancer in 1 patient. There were no flap losses or major complications. With the advancement of free-flap techniques, the classic flaps have become less popular. Our new design supplements the PMMC flap by providing a thin pliable flap with a long pedicle and rotation arc, allowing a combination of different types of flaps to cover composite head and neck defects, especially in cases that lack a reliable recipient vessel due to radiation.

A New Technique for Coronaplasty in Penile Reconstruction.

PubMed

Sommeling, Casper E; De Wolf, Edward J; Salim, Ali; Monstrey, Stan; Opsomer, Dries; Claes, Karel; D'Arpa, Salvatore

2018-06-01

The coronaplasty is an important step of the phalloplasty procedure as it creates a prominent coronal ridge and a constricted coronal sulcus, resulting in the transformation of a regular skin flap into a flap resembling a circumcised penis. The aim of this article is to describe our new coronaplasty technique that exploits opposing contracting forces of 2 different skin grafts to hold the shape of a thick, distally based skin flap, resulting in a natural looking neo-phallus. A distally based flap is raised at the junction of the middle and distal thirds of the neo-phallus. The dissection continues until adequate mobilization is obtained, so the flap can stand almost perpendicular to the axis of the shaft. 2 separate full-thickness skin grafts are harvested and placed: the first at the raw undersurface of the flap, the second at the flap's donor site. To make the sulcus deeper and to define the ridge, the lower part of the graft placed on the undersurface of the distal flap is sutured with tacking sutures. Depending on the type of flap used this procedure can be done during the phalloplasty procedure itself (axial flaps) or at least 1 week later (perforator flaps). The new technique that we developed shows a more distinct coronal sulcus and coronal ridge, long-lasting results, and a more aesthetically pleasing and natural-appearing glans penis. The harvested distal flap is progressively thicker and not folded, resulting in a more naturally looking ridge. The donor site is deeper than other techniques, creating a well-defined sulcus. By using 2 skin grafts the opposing force vectors increase the projection of the ridge and the deepness of the sulcus. This technique results in a more prominent glans penis and is an important step in creating an almost naturally looking neo-phallus. This procedure can be applied to all different kind of flaps used for phalloplasty, both in an immediate or delayed fashion. As grafts are used, partial or complete graft lost can appear. Furthermore, attention must be paid not to incise the distal flap too deep so vascularity to the distal part of the flap will not be impaired. A continuous search to optimize the aesthetic outcome of the phalloplasty procedure is necessary and with this new coronaplasty technique we hope to raise attention and take another step toward creating "the real thing." Sommeling CE, De Wolf EJ, Salim A, et al. A New Technique for Coronaplasty in Penile Reconstruction. J Sex Med 2018;15:920-923. Copyright © 2018 International Society for Sexual Medicine. Published by Elsevier Inc. All rights reserved.

A Mission-Adaptive Variable Camber Flap Control System to Optimize High Lift and Cruise Lift-to-Drag Ratios of Future N+3 Transport Aircraft

NASA Technical Reports Server (NTRS)

Urnes, James, Sr.; Nguyen, Nhan; Ippolito, Corey; Totah, Joseph; Trinh, Khanh; Ting, Eric

2013-01-01

Boeing and NASA are conducting a joint study program to design a wing flap system that will provide mission-adaptive lift and drag performance for future transport aircraft having light-weight, flexible wings. This Variable Camber Continuous Trailing Edge Flap (VCCTEF) system offers a lighter-weight lift control system having two performance objectives: (1) an efficient high lift capability for take-off and landing, and (2) reduction in cruise drag through control of the twist shape of the flexible wing. This control system during cruise will command varying flap settings along the span of the wing in order to establish an optimum wing twist for the current gross weight and cruise flight condition, and continue to change the wing twist as the aircraft changes gross weight and cruise conditions for each mission segment. Design weight of the flap control system is being minimized through use of light-weight shape memory alloy (SMA) actuation augmented with electric actuators. The VCCTEF program is developing better lift and drag performance of flexible wing transports with the further benefits of lighter-weight actuation and less drag using the variable camber shape of the flap.

Gurney flap—Lift enhancement, mechanisms and applications

NASA Astrophysics Data System (ADS)

Wang, J. J.; Li, Y. C.; Choi, K.-S.

2008-01-01

Since its invention by a race car driver Dan Gurney in 1960s, the Gurney flap has been used to enhance the aerodynamics performance of subsonic and supercritical airfoils, high-lift devices and delta wings. In order to take stock of recent research and development of Gurney flap, we have carried out a review of the characteristics and mechanisms of lift enhancement by the Gurney flap and its applications. Optimum design of the Gurney flap is also summarized in this paper. For the Gurney flap to be effective, it should be mounted at the trailing edge perpendicular to the chord line of airfoil or wing. The flap height must be of the order of local boundary layer thickness. For subsonic airfoils, an additional Gurney flap increases the pressure on the upstream surface of the Gurney flap, which increases the total pressure of the lower surface. At the same time, a long wake downstream of the flap containing a pair of counter-rotating vortices can delay or eliminate the flow separation near the trailing edge on the upper surface. Correspondingly, the total suction on the airfoil is increased. For supercritical airfoils, the lift enhancement of the Gurney flap mainly comes from its ability to shift the shock on the upper surface in the downstream. Applications of the Gurney flap to modern aircraft design are also discussed in this review.

"All-laser" endothelial corneal transplant in human patients

NASA Astrophysics Data System (ADS)

Rossi, Francesca; Menabuoni, Luca; Malandrini, Alex; Canovetti, Annalisa; Lenzetti, Ivo; Pini, Roberto

2012-03-01

Femtosecond laser sculpturing of corneal tissue is commonly used for the preparation of endothelial flaps. Diode laser welding of ocular tissues is a procedure that enables minimally invasive suturing of tissues. The combination of these laser based techniques results in a new approach to minimally invasive ophthalmic surgery, such as in endothelial corneal transplant (or endothelial keratoplasty - EK). In this work we present the "all laser" EK performed in human subjects. 24 pseudophakic patients with bullous keratopathy underwent EK: the femtosecond laser was used to prepare the 100 ìm thick and 8.5 mm diameter donor Descemet endothelial flap. After staining the stromal layer of the donor flap with a liquid ICG solution, the donor flap was inserted in the recipient eye by the use of the Busin injector. Then, the endothelial layer was laser-welded to the recipient eye (10 laser spots around the periphery of the flap), in order to reduce the risk of postoperative dislocation of the transplanted flap. A transplanted flap engraftment was observed in all the treated eyes. The staining procedure used to perform laser welding also enabled to evidence the stromal side of the donor flap, so as the flap was always placed in the right side position. The endothelial cells counts in both the laserwelded flaps and in a control group were in good agreement. The proposed technique is easy to perform and enables the reduction of postoperative endothelial flap dislocations.

Wall Boundary Layer Measurements for the NASA Langley Transonic Dynamics Tunnel

NASA Technical Reports Server (NTRS)

Wieseman, Carol D.; Bennett, Robert M.

2007-01-01

Measurements of the boundary layer parameters in the NASA Langley Transonic Dynamics tunnel were conducted during extensive calibration activities following the facility conversion from a Freon-12 heavy-gas test medium to R-134a. Boundary-layer rakes were mounted on the wind-tunnel walls, ceiling, and floor. Measurements were made over the range of tunnel operation envelope in both heavy gas and air and without a model in the test section at three tunnel stations. Configuration variables included open and closed east sidewall wall slots, for air and R134a test media, reentry flap settings, and stagnation pressures over the full range of tunnel operation. The boundary layer thickness varied considerably for the six rakes. The thickness for the east wall was considerably larger that the other rakes and was also larger than previously reported. There generally was some reduction in thickness at supersonic Mach numbers, but the effect of stagnation pressure, and test medium were not extensive.

Biomechanical Changes After LASIK Flap Creation Combined With Rapid Cross-Linking Measured With Brillouin Microscopy.

PubMed

Randleman, J Bradley; Su, Johnny P; Scarcelli, Giuliano

2017-06-01

To evaluate the biomechanical changes occurring after LASIK flap creation and rapid corneal cross-linking (CXL) measured with Brillouin light microscopy. Porcine eyes (n = 11) were evaluated by Brillouin light microscopy sequentially in the following order: virgin state, after LASIK flap creation, and after rapid CXL. Each eye served as its own control. Depth profile of the Brillouin frequency shift was computed to reveal the depth-dependent changes in corneal stiffness. There was a statistically significant reduction of Brillouin shift (reduced corneal stiffness) after LASIK flap creation compared to virgin corneas across total corneal thickness (-0.035 GHz, P = .0195) and within the anterior stromal region (-0.104 GHz, P = .0039). Changes in the central (-0.029 GHz, P = .0391) and posterior (-0.005 GHz, P = .99) stromal regions were not significant. There was a small increase in Brillouin shift after rapid cross-linking that was not statistically or clinically significant across total corneal thickness (0.006 GHz, P = .4688 for any specific stromal region; 0.002 to 0.009 GHz, P > .46 for all). LASIK flap creation significantly reduced Brillouin shift in the anterior third of the stroma in porcine eyes. Rapid corneal cross-linking had no significant effect on Brillouin shift after LASIK flap creation in porcine eyes. With further validation, non-contact, non-perturbative Brillouin microscopy could become a useful monitoring tool to evaluate the biomechanical impact of corneal refractive procedures and corneal cross-linking protocols. [J Refract Surg. 2017;33(6):408-414.]. Copyright 2017, SLACK Incorporated.

Medial sural artery perforator flap: a challenging free flap.

PubMed

Toyserkani, Navid Mohamadpour; Sørensen, Jens Ahm

Oral and extremity defect reconstruction can often require a flap that is thin, and traditionally, the radial forearm free flap has been used, however, this has significant donor site morbidity. Over the last decade, the medial sural artery perforator (MSAP) flap has emerged as a possible alternative with lower donor site morbidity. We present our experiences and review the literature regarding this promising but challenging flap. The study was a retrospective case series in a university hospital setting. All patients who had a MSAP flap performed at our institution were included until March 2015, and their data was retrieved from electronic patient records. In total, ten patients were reconstructed with a MSAP flap for floor of mouth (eight) and lower extremity (two) defect reconstruction. The median flap dimensions were as follows: 10 cm (range 7-14 cm), width 5 cm (range 3.5-8 cm), thickness 5 mm (range 4-8 mm), and pedicle length 10 cm (range 8-12 cm). In one case, the procedure was abandoned because of very small perforators and another flap was used. In two cases, late onset of venous congestion occurred which could not be salvaged. There were no donor site complaints. The MSAP flap is an ideal flap when a thin free flap is needed with lower donor site morbidity than alternative solutions. There seems to be a higher rate of late onset of venous thrombosis compared with more established flaps. Therefore, this flap should be monitored more closely for venous problems and we recommend performing two venous anastomoses when using this flap. Level of Evidence: Level IV, therapeutic study.

Histological case-control study of peeling-induced skin changes by different peeling agents in surgically subcutaneous undermined skin flaps in facelift patients.

PubMed

Gonser, P; Kaestner, S; Jaminet, P; Kaye, K

2017-11-01

A histological evaluation of peeling-induced skin changes in subcutaneous undermined preauricular facial skin flaps of nine patients was performed. There were three treatment groups: Trichloroacetic acid (TCA) 25%, TCA 40% and phenol/croton oil; one group served as control. Two independent evaluators determined the epidermal and dermal thickness and the depth of necrosis (micrometre). The percentual tissue damage due to the peeling was calculated, and a one-sample t-test for statistical significance was performed. On the basis of the histomorphological changes, peeling depth was classified as superficial, superficial-partial, deep-partial and full thickness chemical burn. The histological results revealed a progression of wound depth for different peeling agents without full thickness necrosis. TCA peels of up to 40% can be safely applied on subcutaneous undermined facial skin flaps without impairing the vascular patency, producing a predictable chemical burn, whereas deep peels such as phenol/croton oil peels should not be applied on subcutaneous undermined skin so as to not produce skin slough or necrosis by impairing vascular patency. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Changes in Keratocyte Density and Visual Function Five Years after Laser in situ Keratomileusis: Femtosecond Laser vs Mechanical Microkeratome

PubMed Central

McLaren, Jay W.; Bourne, William M.; Maguire, Leo J.; Patel, Sanjay V.

2015-01-01

Purpose To determine the effects of keratocyte loss on optical properties and vision after laser in situ keratomileusis (LASIK) with the flap created with a femtosecond laser or a mechanical microkeratome. Design Randomized clinical paired-eye study. Methods Both eyes of 21 patients received LASIK for myopia or myopic astigmatism. One eye of each patient was randomized by ocular dominance to flap creation with a femtosecond laser and the other eye to flap creation with a mechanical microkeratome. Before LASIK and at 1, 3, 6 months and 1, 3, and 5 years after LASIK, keratocyte density was measured by using confocal microscopy, and high-contrast visual acuity and anterior corneal wavefront aberrations were measured by standard methods. At each visit, all variables were compared between methods of creating the flap and to the same variable before treatment by using paired tests with Bonferroni correction for multiple comparisons. Results Keratocyte density in the flap decreased by 20% during the first year after LASIK and remained low through 5 years (p<0.001). High-order wavefront aberrations increased and uncorrected visual acuity improved immediately after surgery but these variables did not change further to five years. There were no differences in any variables between treatments. Conclusions A sustained reduction in keratocyte density does not affect vision or optical properties of the cornea through 5 years after LASIK. The method of creating a LASIK flap does not influence the changes in keratocyte density in the flap. PMID:25868758

Clinical applications of perforator-based propeller flaps in upper limb soft tissue reconstruction.

PubMed

Ono, Shimpei; Sebastin, Sandeep J; Yazaki, Naoya; Hyakusoku, Hiko; Chung, Kevin C

2011-05-01

A propeller flap is an island flap that moves from one orientation to another by rotating around its vascular axis. The vascular axis is stationary, and flap movement is achieved by revolving on this axis. Early propeller flaps relied on a thick, subcutaneous pedicle to maintain vascularity, and this limited the flap rotation to 90°. With increasing awareness of the location and the vascular territory perfused by cutaneous perforators, it is now possible to design propeller flaps based on a single perforator, so-called "perforator-based propeller flaps." These flaps permit flap rotation up to 180°. We present the results of upper limb soft tissue reconstruction using perforator-based propeller flaps. We constructed a treatment strategy based on the location of the soft tissue defect and the perforator anatomy for expedient wound coverage in 1 stage. All perforator-based propeller flaps derived from 3 institutions that were used for upper limb soft tissue reconstruction were retrospectively analyzed. The parameters studied included the size and location of the defect, the perforator that was used, the size and shape of the flap, the direction (ie, clockwise or counter-clockwise) of flap rotation, the degree of twisting of the perforator, the management of the donor site (ie, linear closure or skin grafting), and flap survival (recorded as the percentage of the flap area that survived). Twelve perforator-based propeller flaps were used to reconstruct upper limb soft tissue defects in 12 patients. Six different perforators were used as vascular pedicles. The donor defects of 11 flaps could be closed primarily. One flap was partially lost in a patient with electrical burns. Perforator-based propeller flaps provide a reliable option for covering small- to medium-size upper limb soft tissue defects. Copyright © 2011 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Computational Study of Porous Treatment for Altering Flap Side-Edge Flowfield

NASA Technical Reports Server (NTRS)

Choudhari, Meelan; Khorrami, Mehdi R.

2003-01-01

Reynolds-averaged Navier-Stokes calculations are used to investigate porous side-edge treatment as a passive means for flap noise reduction. Steady-state simulations are used to infer effects of the treatment on acoustically relevant features of the mean flow near the flap side edge. Application of the porous treatment over a miniscule fraction of the wetted flap area (scaling with the flap thickness) results in significantly weaker side-edge vortex structures via modification of the vortex initiation and roll-up processes. At high flap deflections, the region of axial flow reversal associated with the breakdown of the side-edge vortex is also eliminated, indicating an absence of vortex bursting in the presence of the treatment. Potential ramifications of the mean-flow modifications for flap-noise reduction are examined in the light of lessons learned from recent studies on flap noise. Computations confirm that any noise reduction benefit via the porous treatment would be achieved without compromising the aerodynamic effectiveness of the flap. Results of the parameter study contribute additional insight into the measured data from the 7x10 wind tunnel at NASA Ames and provide preliminary guidance for specifying optimal treatment characteristics in terms of treatment location, spatial extent, and flow resistance of the porous skin.

[Free gracilis muscle flap with plantar intermediate thickness skin graft: case report, review of anatomy and functional reconstruction of the palm].

PubMed

Engelhardt, T O; Rieger, U M; Baltaci, M; Pierer, G; Schwabegger, A H

2011-08-01

Skin and soft-tissue architecture of the palm are unique. Coverage of extensive soft-tissue defects restoring the functional capacity of the palm remains a challenging task. Anatomic restoration with skin from another area is hardly possible. In manual labourers, reconstruction of mechanical soft-tissue stability is required in addition to sensation, range of motion and grip strength. Sensate fasciocutaneous flaps bear disadvantages of tissue mobility, shifting and bulkiness. Published criteria for defect-related flap selection are sparse. Defect analysis (anatomy, units of tactile gnosis, individual parameters) provides information to weigh needs for sensation or tissue stability, influencing selection of most appropriate procedures. We distinguished 4 units: hypothenar (H), thenar (T) and central palm (Z). (Z) consists of a central palmar unit (c') and the distal palm (d'). Individual parameters (age, profession, dominant hand, psychosocial aspects) were also considered. Units (T) and (H), regions of secondary touch, demand protective sensation by applying sensate fasciocutaneous flaps. In labourers tactile gnosis in (Z) is of less, tissue stability of greater value. An extensive palmar defect (9×13 cm, affecting unit (Z), partially affecting units (T) and (H), of the dominant hand) with combined vessel, nerve, tendon injuries (male labourer, 21 years) was covered after defect analysis with a free gracilis muscle flap and a glabrous intermediate (0.5 mm) thickness skin graft from the instep region. 29 months postoperatively anatomic conditions of palmar soft tissue (Vancouver scar scale: 1), high mechanical soft-tissue stability including normal hand function were evident. Semmes Weinstein testing showed positive pressure sensation. Professional reintegration after 5 months was possible. Defect coverage of the palm must not consist of merely providing sensate vascularised tissue. The most appropriate procedure can be derived from careful defect analysis focusing on the affection of units of tactile gnosis to achieve near to anatomic reconstruction. In labourers, patient- and defect-related demands need close correlation with the value of the selected flaps regarding the sensation and mechanical stability to be expected. In selected cases (mechanical irritation, affection of unit (Z), younger age) by combining microvascular muscle flaps with plantar intermediate thickness skin grafts promising functional results with early professional reintegration can be achieved by reconstructing like with like. © Georg Thieme Verlag KG Stuttgart · New York.

[Pedicled versus free TRAM flap for breast reconstruction].

PubMed

Galla, T J; Lukas, B; Feller, A M

1999-03-01

In breast reconstruction, the free TRAM-flap offers many advantages over the pedicled TRAM-flap. Due to its superior perfusion, the free flap rarely develops necrosis. Shaping of the flap is easier due to the lack of the thick muscle pedicle. Because the rectus muscle is spared, there is minimal donor site morbidity. However, the necessary microvascular anastomoses reduced the acceptance of the free TRAM-flap. During a 13-months period, 51 breast reconstructions were performed in 41 patients, 31 unilateral and ten bilateral. 45 flaps served for delayed reconstruction and six flaps for immediate reconstruction. The operations were performed by two teams working simultaneously. The average operating time was 3.9 hours for unilateral and 6.9 hours for bilateral delayed reconstruction. For immediate reconstruction, 6.2 and 6.3 hours were required for uni- and bilateral procedures, respectively. In 38 flaps, the thoracodorsal vessels served as recipient vessels; 13 flaps were anastomosed to the internal mammary artery and vein. Postoperative complications were observed in 13 patients. Three vessel anastomoses had to be revised. In one flap, a partial necrosis occurred; in two flaps hematoma evacuation was necessary. Two patients suffered from fat necroses at the abdomen and one umbilicus was lost. Skin irritations and seromas at the abdomen occurred in five patients. Pulmonary embolism was diagnosed in one patient three weeks postoperatively. Abdominal hernias or bulging in the epigastric area were not observed up to 15 months after reconstruction. These results reveal a low complication rate for breast reconstruction with the free TRAM-flap. The advantages of this technique as compared to the pedicled technique are discussed.

Analysis of high aspect ratio jet flap wings of arbitrary geometry.

NASA Technical Reports Server (NTRS)

Lissaman, P. B. S.

1973-01-01

Paper presents a design technique for rapidly computing lift, induced drag, and spanwise loading of unswept jet flap wings of arbitrary thickness, chord, twist, blowing, and jet angle, including discontinuities. Linear theory is used, extending Spence's method for elliptically loaded jet flap wings. Curves for uniformly blown rectangular wings are presented for direct performance estimation. Arbitrary planforms require a simple computer program. Method of reducing wing to equivalent stretched, twisted, unblown planform for hand calculation is also given. Results correlate with limited existing data, and show lifting line theory is reasonable down to aspect ratios of 5.

The clinical effect of acellular dermal matrix on gingival thickness and root coverage compared to coronally positioned flap alone.

PubMed

Woodyard, James G; Greenwell, Henry; Hill, Margaret; Drisko, Connie; Iasella, John M; Scheetz, James

2004-01-01

The primary aim of this randomized, controlled, blinded, clinical investigation was to compare the coronally positioned flap (CPF) plus an acellular dermal matrix (ADM) allograft to CPF alone to determine their effect on gingival thickness and percent root coverage. Twenty-four subjects with one Miller Class I or II buccal recession defect of > or = 3 mm were treated with a CPF plus ADM or a CPF alone. Multiple additional recession sites were treated with the same flap procedure, and all sites were studied for 6 months. Tissue thickness was measured at the sulcus base and at the mucogingival junction of all teeth, with an SDM ultrasonic gingival thickness meter. For the ADM sites, mean initial recession of 3.46 mm was reduced to 0.04 mm for defect coverage of 3.42 mm or 99% (P < 0.05). For the CPF group, mean initial recession of 3.27 mm was reduced to 1.08 mm for defect coverage of 2.19 mm or 67% (P < 0.05). The difference between ADM and CPF groups was statistically significant (P < 0.05). Marginal soft-tissue thickness was increased by 0.40 mm (P < 0.05) for the ADM group, whereas the CPF group remained essentially unchanged. Keratinized tissue was increased for the ADM group by 0.81 mm (P < 0.05), whereas the CPF group increased by 0.33 mm (P > 0.05). No additional root coverage was gained due to creeping attachment between 2 and 6 months for either group. Treatment with a CPF plus an ADM allograft significantly increased gingival thickness when compared with a CPF alone. Recession defect coverage was significantly improved with the use of ADM.

Variable area nozzle for gas turbine engines driven by shape memory alloy actuators

NASA Technical Reports Server (NTRS)

Rey, Nancy M. (Inventor); Miller, Robin M. (Inventor); Tillman, Thomas G. (Inventor); Rukus, Robert M. (Inventor); Kettle, John L. (Inventor); Dunphy, James R. (Inventor); Chaudhry, Zaffir A. (Inventor); Pearson, David D. (Inventor); Dreitlein, Kenneth C. (Inventor); Loffredo, Constantino V. (Inventor)

2001-01-01

A gas turbine engine includes a variable area nozzle having a plurality of flaps. The flaps are actuated by a plurality of actuating mechanisms driven by shape memory alloy (SMA) actuators to vary fan exist nozzle area. The SMA actuator has a deformed shape in its martensitic state and a parent shape in its austenitic state. The SMA actuator is heated to transform from martensitic state to austenitic state generating a force output to actuate the flaps. The variable area nozzle also includes a plurality of return mechanisms deforming the SMA actuator when the SMA actuator is in its martensitic state.

Factors influencing flap and INTACS decentration after femtosecond laser application in normal and keratoconic eyes.

PubMed

Ertan, Aylin; Karacal, Humeyra

2008-10-01

To compare accuracy of LASIK flap and INTACS centration following femtosecond laser application in normal and keratoconic eyes. This is a retrospective case series comprising 133 eyes of 128 patients referred for refractive surgery. All eyes were divided into two groups according to preoperative diagnosis: group 1 (LASIK group) comprised 74 normal eyes of 72 patients undergoing LASIK with a femtosecond laser (IntraLase), and group 2 (INTACS group) consisted of 59 eyes of 39 patients with keratoconus for whom INTACS were implanted using a femtosecond laser (IntraLase). Decentration of the LASIK flap and INTACS was analyzed using Pentacam. Temporal decentration was 612.56 +/- 384.24 microm (range: 30 to 2120 microm) in the LASIK group and 788.33 +/- 500.34 microm (range: 30 to 2450 microm) in the INTACS group. A statistically significant difference was noted between the groups in terms of decentration (P < .05). Regression analysis showed that the amount of decentration of the LASIK flap and INTACS correlated with the central corneal thickness in the LASIK group and preoperative sphere and cylinder in the INTACS group, respectively. Decentration with the IntraLase occurred in most cases, especially in keratoconic eyes. The applanation performed for centralization during IntraLase application may flatten and shift the pupil center, and thus cause decentralization of the LASIK flap and INTACS. Central corneal thickness in the LASIK group and preoperative sphere and cylinder in the INTACS group proved to be statistically significant parameters associated with decentration.

Variable Camber Continuous Aerodynamic Control Surfaces and Methods for Active Wing Shaping Control

NASA Technical Reports Server (NTRS)

Nguyen, Nhan T. (Inventor)

2016-01-01

An aerodynamic control apparatus for an air vehicle improves various aerodynamic performance metrics by employing multiple spanwise flap segments that jointly form a continuous or a piecewise continuous trailing edge to minimize drag induced by lift or vortices. At least one of the multiple spanwise flap segments includes a variable camber flap subsystem having multiple chordwise flap segments that may be independently actuated. Some embodiments also employ a continuous leading edge slat system that includes multiple spanwise slat segments, each of which has one or more chordwise slat segment. A method and an apparatus for implementing active control of a wing shape are also described and include the determination of desired lift distribution to determine the improved aerodynamic deflection of the wings. Flap deflections are determined and control signals are generated to actively control the wing shape to approximate the desired deflection.

Effect of topically applied minoxidil on the survival of rat dorsal skin flap.

PubMed

Gümüş, Nazım; Odemiş, Yusuf; Yılmaz, Sarper; Tuncer, Ersin

2012-12-01

Flap necrosis still is a challenging problem in reconstructive surgery that results in irreversible tissue loss. This study evaluated the effect of topically applied minoxidil on angiogenesis and survival of a caudally based dorsal rat skin flap. For this study, 24 male Wistar rats were randomly divided into three groups of eight each. A caudally based dorsal skin flap with the dimensions of 9 × 3 cm was raised. After elevation of the flaps, they were sutured back into their initial positions. In group 1 (control group), 1 ml of isotonic saline was applied topically to the flaps of all the animals for 14 days. In group 2, minoxidil solution was spread uniformly over the flap surface for 7 days after the flap elevation. In group 3, minoxidil solution was applied topically to the flap surface during a 14-day period. On day 7 after the flap elevation, the rats were killed. The average area of flap survival was determined for each rat. Subdermal vascular architecture and angiogenesis were evaluated under a light microscope after two full-thickness skin biopsy specimens had been obtained from the midline of the flaps. The lowest flap survival rate was observed in group 1, and no difference was observed between groups 1 and 2. Compared with groups 1 and 2, group 3 had a significantly increased percentage of flap survival (P < 0.05). Intense and moderate angiogenesis also was observed respectively at the proximal and distal areas of the flaps in group 3. The results of this experiment seem to show that the early effect of minoxidil is vasodilation and that prolonged use before flap elevation leads to angiogenesis, increasing flap viability. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Complex posterior thoracic wall reconstruction using a crossover combined latissimus dorsi and serratus anterior free flap.

PubMed

Bodin, Frédéric; Dissaux, Caroline; Steib, Jean-Paul; Massard, Gilbert

2016-03-01

Radical resection of an extended malignant sarcoma of the chest wall requires full-thickness thoracic chest wall reconstruction. Reconstruction is tedious in the case of posteriorly located tumours, because the ipsilateral pedicled myocutaneous latissimus dorsi flap is involved and hence not usable for soft tissue coverage. We report an original case of a left giant dorsal chondrosarcoma originating from the 11th costovertebral joint. After extended resection and skeletal reconstruction, soft tissue coverage was achieved with an original contralateral free flap encompassing both latissimus dorsi and serratus anterior muscles. The flap pedicle was anastomosed to the ipsilateral thoracodorsal vessels. © The Author 2015. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery. All rights reserved.

Elbow reconstruction with a pedicled thoracodorsal artery perforator flap after excision of an upper-extremity giant hairy nevus.

PubMed

Oksüz, Sinan; Ulkür, Ersin; Tuncer, Serhan; Sever, Celalettin; Karagöz, Hüseyin

2013-04-01

The complexity of managing large soft-tissue defects at the elbow region by conventional techniques arises from the difficulty of providing sufficient tissue with adequate elasticity and durability. Reconstruction options that allow early mobilisation and avoid the risk of functional loss should be considered to achieve defect closure at the elbow region. A 21-year-old man presented with a congenital giant hairy nevus on his left upper extremity. The nevus was excised and the resulting raw surface after the excision was covered with a split-thickness skin graft except for the elbow region. The elbow was covered in one stage with an ipsilateral 24 cm long pedicled thoracodorsal artery perforator (TDAP) flap. The follow-up examination 3 years after total reconstruction demonstrated durable elbow support provided by the TDAP flap. The patient revealed no complaint considering pain or sensitivity even when exposed to mechanical stress. Split-thickness skin grafting of the large superficial defects is almost always possible; however, impairment of the function on joint areas due to gradual contraction and skin graft propensity to ulcers under mechanical stresses can be devastating. The elbow is a weight-bearing area of the body. Elbow defects require durable and thin soft-tissue coverage and the tissue cover must possess excellent elastic properties to re-establish elbow mobility. The TDAP flap is an ideal choice for elbow soft-tissue defects. The longest pedicle length reported for the TDAP flap is 23 cm. In our case, the pedicle length was 24 cm and it was possible to transfer this flap to the elbow on its pedicle. A pedicled TDAP skin flap so as to provide elbow coverage in one stage is a useful choice to retain in one's armamentarium. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Reconstruction of a traumatic plantar foot defect with a novel free flap: The medial triceps brachii free flap.

PubMed

Leclère, Franck Marie; Casoli, Vincent

2015-01-01

Lower extremity defects may account for 14.6% of the approximately 117 million visits to emergency departments in the U. S. in 2007. In this article, we present a reconstruction of a traumatic plantar foot defect with a medial triceps brachii (MTB) free flap. A 53-year-old man sustained an accidental gunshot wound to the right foot. The patient was admitted after the failure of a sural flap procedure performed in another hospital. He presented with a soft-tissue defect with calcaneal exposition and osteomyelitis. The defect was reconstructed with a MTB free flap anastomosed to his dorsalis pedis vessels. Flap raising time was 52 min. There were no intraoperative complications. The total flap surface was 38.5 cm². The pedicle length was 3 cm. The diameters of the artery and vein of the flap pedicle were 1.1 mm and 1.4 mm, respectively. Ischemia time was 28 min. His donor site healed uneventfully without any morbidity, and the scar was well concealed. The flaps survived and there was no partial flap necrosis. A split-thickness skin graft was performed 12 days postoperatively. Two months later, he had a completely healed wound with no contour abnormality. The total follow-up was 24 months. The patient was able to walk normally. MTB free flap appears to be an excellent option for plantar foot defects in patients with preserved vascularization of the foot. Due to the anatomical shape of the flap, the position of its pedicle, and the moldability of the muscle, we predict that the use of the MTB free flap will grow and develop rapidly for reconstruction of ankle and foot defects.

Temporalis myo-osseous flap: an experimental study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Antonyshyn, O.; Colcleugh, R.G.; Hurst, L.N.

1986-03-01

The present paper investigates the anatomy and vascularization of the temporalis myo-osseous flap. This is a calvarial bone flap that employs temporalis muscle and its distal pericranial extension as a pedicle. In six human cadavers the flap was raised as an island on the anterior deep temporal artery after transecting the zygomatic arch and coronoid process. Maximal mobilization was thus obtained, allowing rotation of the flap into the mouth for intraoral reconstruction. The arc of rotation and potential surgical applications were noted. A comparative study of the temporalis myo-osseous flap and free calvarial bone graft was then conducted in amore » rabbit model. Vascularization of the calvarial bone flap was confirmed by technetium scintigraphy performed on the first postoperative day. The uptake of fluorochrome labels immediately after transfer verified the adequacy of the periosteal circulation in maintaining viability and new osteoid formation throughout the full thickness of calvarial bone. The transplantation of free calvarial bone grafts was followed by necrosis of most cellular elements. This was demonstrated by an absence of fluorochrome uptake up to 19 days postoperatively and a predominance of empty lacunae and nonviable marrow.« less

Nasofacial defect following fibrosarcoma excision and radiotherapy.

PubMed

Burget, G L; Panje, W R; Krause, C J

1988-01-01

For initial reconstruction, Dr. Burget suggests that he would have advanced the cheek flap medially toward the nasal septum and, subsequently, reconstructed the missing right half of the nose with a forehead flap and cartilage grafts. Dr. Panje suggested early prosthetic rehabilitation, while Dr. Krause's concepts were similar to Dr. Burget's, with forehead flap nasal reconstruction, after cheek reconstruction to the nasofacial and nasolabial lines with a medially advanced cheek flap. Dr. Panje recommended an immediate maxillary denture prosthesis, as did Dr. Krause (who supplemented this with foam rubber). Dr. Burget placed the prosthesis 3 weeks after tumor ablation. For skin grafts, Drs. Panje and Burget suggested split thickness grafts to all new surfaces to decrease wound contracture, while Dr. Krause used dermis grafts for the same purpose. Other reconstructive methods mentioned were the (1) cervical tubed flap, (2) free scapular flap, (3) Washio flap, (4) tissue expansion, and (5) nasolabial flap. Suggestions for isolated defects included: Lower eyelid--increase internal support by building up the prosthesis; release lower lid from deltopectoral flap and V-Y advancement; support graft or irradiated cartilage (1-2 mm sheet) under orbicularis oculi. Nasal ala--bring present ala down and insert cartilage graft; turn internal skin down and fill the resulting defect with a composite graft. Upper lip--multiple Z-plasty. Retrodisplacement of cheek due to maxillectomy--release buccal scar; skin graft the raw internal surface and build up prosthesis.

SWEPT-SOURCE OPTICAL COHERENCE TOMOGRAPHY ANGIOGRAPHY REVEALS INTERNAL LIMITING MEMBRANE PEELING ALTERS DEEP RETINAL VASCULATURE.

PubMed

Michalewska, Zofia; Nawrocki, Jerzy

2018-04-30

To describe morphology of retinal and choroidal vessels in swept-source optical coherence tomography angiography before and after vitrectomy with the temporal inverted internal limiting membrane (ILM) flap technique for full-thickness macular holes. Prospective, observational study of 36 eyes of 33 patients with full-thickness macular holes swept-source optical coherence tomography angiography was performed in patients before and 1 month after vitrectomy. Vitrectomy with the temporal inverted ILM flap technique was performed. In this method, ILM is peeled only at one side of the fovea. An ILM flap is created to cover the macular hole. Comparison of retina vasculature in the areas of ILM peeling vs. no ILM peeling at 1 and 3 months after successful vitrectomy was performed. The study demonstrated lower density of vessels in the deep retinal plexus in the area where ILM was peeled as compared to the rest of the fovea. Visual acuity and central retinal thickness 1 month after surgery correlates with fovea avascular zone diameter in deep retinal layers at the same time point (P = 0.001). This study confirmed that ILM peeling might alter blood flow in deep retinal vessels below the peeling area in the early postoperative period. The area of the fovea avascular zone corresponds to functional results at the same time point.

Reverse pedicle-based greater saphenous neuro-veno-fasciocutaneous flap for reconstruction of lower leg and foot.

PubMed

Kansal, Sandeep; Goil, Pradeep; Agarwal, Vijay; Agarwal, Swarnima; Mishra, Shashank; Agarwal, Deepak; Singh, Pranay

2014-01-01

Paucity of soft tissue available locally for reconstruction of defects in leg and foot presents a challenge for reconstructive surgeon. The use of reverse pedicle-based greater saphenous neuro-veno-fasciocutaneous flap in reconstruction of lower leg and foot presents a viable alternative to free flap and cross-leg flap reconstruction. The vascular axis of the flap is formed by the vessels accompanying the saphenous nerve and the greater saphenous vein. We present here our experience with reverse saphenous neurocutaneous flap which provides a stable cover without the need to sacrifice any important vessel of leg. The study is conducted from March 2003 through Dec 2009 and included a total of 96 patients with defects in lower two-thirds of leg and foot. There are 74 males and 22 females. Distal pivot point was kept approximately 5-6 cm from tip of medial malleolus, thus preserving the distal most perforator, and the flap is turned and inserted into the defect. Donor site is covered with a split thickness skin graft. Postoperative follow-up period was 6 weeks to 6 months. The procedure is uneventful in 77 cases. Infection is observed in 14 cases. Partial flap necrosis occurs in 2 cases. Total flap necrosis is noted in 3 cases. Reverse pedicle saphenous flap can be used to reconstruct defects of lower one-third leg and foot with a reliable blood supply with a large arc of rotation while having minimal donor site morbidity.

"Palmar pivot flap" for resurfacing palmar lateral defects of the fingers.

PubMed

Yam, Andrew; Peng, Yeong-Pin; Pho, Robert Wan-Heng

2008-12-01

Soft tissue defects on the lateral borders of the digits are difficult to reconstruct using local or local-regional flaps. We describe a "palmar pivot flap" to resurface an adjacent defect on the palmar-lateral aspect of the digit. The surgical technique is described. This flap is an axial pattern flap based on the subcutaneous transverse branches of the digital artery. The flap is pivoted up to 90 degrees on the neurovascular bundle in its base, into an adjacent defect. The flap can be raised from either the proximal or the middle phalangeal segments. It can cover defects sited from the level of the proximal interphalangeal joint up to the fingertip. The donor defect is limited to the same digit and is covered with a full-thickness skin graft. We have used this flap on 3 patients with defects at the middle phalangeal segment, the distal interphalangeal joint, and the fingertip. All healed primarily. One patient had a mild flexion contracture of the proximal interphalangeal joint, whereas the other 2 had no complications. The patients with distal interphalangeal joint and fingertip defects had excellent sensation in the flap (2-point discrimination of 5-6 mm). The palmar pivot flap is useful for resurfacing otherwise difficult defects on the lateral borders of the digits around and distal to the proximal interphalangeal joint, including those at the fingertip. It provides sensate, glabrous skin. The donor defect is on the same digit and is well hidden, producing an aesthetic and functional reconstruction.

Low-Speed Wind-Tunnel Investigation to Determine the Aerodynamic Characteristics of a Rectangular Wing Equipped with a Full-Span and an Inboard Half-Span Jet-Augmented Flap Deflected 55 deg

NASA Technical Reports Server (NTRS)

Gainer, Thomas G.

1959-01-01

An investigation to determine the aerodynamic characteristics of a rectangular wing equipped with a full-span and an inboard half-span jet-augmented flap has been made in the Langley 300 MPH 7- by 10-foot tunnel. The wing had an aspect ratio of 8.3 and a thickness-chord ratio of 0.167. A jet of air was blown backward through a small gap, tangentially to the upper surface of a round trailing edge, and was separated from the trailing edge by a very small flap at an angle of 55 deg with respect to the wing-chord plane. The results of the investigation showed that the ratio of total lift to jet-reaction lift for the wing was about 35 percent less for the half-span jet-augmented flap than for the full-span jet-augmented flap. The reduction of the span of the jet-augmented flap from full to half span reduced the maximum value of jet-circulation lift coefficient that could be produced from about 6.8 to a value of about 2.2. The half-span jet- augmented flap gave thrust recoveries considerably poorer than those obtained with the full-span jet-augmented flap. Large nose-down pitching- moment coefficients were produced by the half-span flap, with the greater part of these being the result of the larger jet reactions required to produce a given lift for the half-spin flap compared with that required for the full-span flap.

Risk Factor Analysis of Freestyle Propeller Flaps.

PubMed

Paik, Joo Myong; Pyon, Jai-Kyong

2017-01-01

Background  Freestyle propeller flaps have been widely used as a reconstructive option for both trunk and extremities. It offers the advantage of "like-with-like" reconstruction with an adjacent tissue with no dissection to the source vessels. However, there is the risk of vascular complications. In the present study, the authors investigated the incidence of vascular complications and their risk factors following freestyle propeller flap in the trunk and extremities. Methods  The authors conducted a retrospective review of 50 patients who underwent soft tissue reconstruction of the trunk and the extremities with 55 freestyle propeller flaps from 2004 to 2015. Data regarding patient demographics, surgical details, including the arc of rotation, and flap complications were collected from a prospectively maintained database and analyzed. Results  There were 10 flap complications (18.2%), including 7 superficial partial necrosis, 2 full-thickness partial necrosis, and 1 total necrosis from the 55 freestyle propeller flaps harvested. Previous irradiation was a significant risk factor for flap complications and the propeller flap harvested from the extremities showed a significantly higher rate of complications compared with those harvested from the trunk. Complication rates were higher in flaps with the arc of rotation between 150 and 180 degrees with marginal significance compared with flaps with the arc of rotation less than 150 degrees. Conclusions  Freestyle propeller flaps proved to be a valid and reliable option for reconstruction of defects in the trunk, while complication rate was quite high in the extremities. A prudent preoperative evaluation and preparation may be necessary before performing this surgical technique in the extremities. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Functional and esthetic outcome enhancement of periodontal surgery by application of plastic surgery principles.

PubMed

Hürzeler, M B; Weng, D

1999-02-01

The closure of surgical wounds in a layer-by-layer fashion, a common principle of plastic surgery, is applied in this article to the field of periodontal surgery with the introduction of a new flap design. The suggested technique is indicated with all periodontal procedures that aim for hard and soft tissue augmentation (guided bone regeneration, mucogingival surgery, or plastic periodontal surgery) where passive, tension-free wound closure is fundamental for wound healing and a successful functional and esthetic outcome. By means of a series of incisions, buccal and lingual flaps are split several times; this results in a double-partial thickness flap and a coronally positioned palatal sliding flap, respectively. Thus, several tissue layers are obtained and the passive advancement of flaps becomes possible for the coverage of augmented areas. Wound closure with microsurgical suture material is accomplished in a multilayer approach, which ensures adaptation and closure of the outer tissue layers without any tension. Two case reports demonstrate the new plastic periodontal approach.

Full Scale Span Load Distribution on a Tapered Wing with Split Flaps of Various Spans

NASA Technical Reports Server (NTRS)

Parsons, John F; Silverstein, Abe

1937-01-01

Pressure-distribution tests were conducted in the full-scale wind tunnel on a 2:1 tapered U.S.A. 45 airfoil equipped with 20 percent chord split trailing-edge flaps of various spans. A special installation was employed in the tests utilizing a half-span airfoil mounted vertically above a reflection plane. The airfoil has a constant chord center section and rounded tips and is tapered in thickness from 18 percent c at the root to 9 percent c at the tip. The aerodynamic characteristics, given by the usual dimension less coefficients, are presented graphically as functions of flap span and angle of attack as well as by semispan load diagrams. The results indicate, in general, that only a relatively small increase in the normal-force coefficient is to be expected by extending the flap span of an airfoil-flap combination, similar to the one tested, beyond 70 percent of the wing span.

The investigation of a variable camber blade lift control for helicopter rotor systems

NASA Technical Reports Server (NTRS)

Awani, A. O.

1982-01-01

A new rotor configuration called the variable camber rotor was investigated numerically for its potential to reduce helicopter control loads and improve hover performance. This rotor differs from a conventional rotor in that it incorporates a deflectable 50% chord trailing edge flap to control rotor lift, and a non-feathering (fixed) forward portion. Lift control is achieved by linking the blade flap to a conventional swashplate mechanism; therefore, it is pilot action to the flap deflection that controls rotor lift and tip path plane tilt. This report presents the aerodynamic characteristics of the flapped and unflapped airfoils, evaluations of aerodynamics techniques to minimize flap hinge moment, comparative hover rotor performance and the physical concepts of the blade motion and rotor control. All the results presented herein are based on numerical analyses. The assessment of payoff for the total configuration in comparison with a conventional blade, having the same physical characteristics as an H-34 helicopter rotor blade was examined for hover only.

Versatility of the Angularis Oris Axial Pattern Flap for Facial Reconstruction.

PubMed

Losinski, Sara L; Stanley, Bryden J; Schallberger, Sandra P; Nelson, Laura L; Towle Millard, Heather A M

2015-11-01

To describe the versatility of the axial pattern flap based on the cutaneous perforating branch of the angularis oris artery for reconstruction of large facial defects in dogs, including complications and clinical outcomes. Retrospective clinical case series. Client-owned dogs (n = 8). Facial flaps (n = 9) based at the commissure of the lip with a caudodorsal orientation were utilized, with established anatomical borders. Flaps were elevated deep to the panniculus carnosus in a caudal to rostral direction, preserving the angularis oris artery, its cutaneous perforator, and surrounding cutaneous vasculature. Flaps were rotated dorsally or ventrally to cover the defect. Primary closure of the donor site was by direct apposition in all cases. Angularis oris axial pattern flaps were most commonly used to close large defects of the nasomaxillary area rostral to the eyes (6 dogs), followed by orbital (2) and intermandibular (1) defects. Defects occurred because of tumor resection (6 dogs), trauma (2), and a chronic, non-healing wounding (1). All flaps healed with acceptable functional and cosmetic outcomes without major complications. Followup ranged from 10 days to 16 months. Minor postoperative complications included flap edema (8 dogs), partial incisional dehiscence (3), distal tip necrosis (2), and oroantral fistula recurrence (1). Angularis oris axial pattern flaps provided hirsute, full-thickness skin coverage of a variety of large facial defects with minor complications, and should be considered when restructuring large defects of the rostral face or chin. © Copyright 2015 by The American College of Veterinary Surgeons.

Digital Image Correlation of Flapping Wings for Micro-Technologies

DTIC Science & Technology

2011-08-01

polyethylene ( LDPE ) 0.03-mm-thick plastic was used for the wing skin, which was tautly stretched and taped to a solid surface. The LDPE is adhered to the wing...simplicity purposes and to maintain minimal skin thickness. Unfortunately, the effect of adding the paint to the LDPE is unknown since the wing must

Sternocleidomastoid myofascial flap for reconstruction after composite resection of invasive squamous cell carcinoma of the tonsillar region: technique and outcome.

PubMed

Laccourreye, Ollivier; Ménard, Madeleine; Behm, Eva; Garcia, Dominique; Cauchois, Régis; Holsinger, F Christopher

2006-11-01

To present the surgical technique and determine the efficacy of sternocleidomastoid myofascial (SCMF) flap reconstruction after composite resection with intent to cure. Retrospective review of 73 consecutive patients with a previously isolated and untreated moderately to well-differentiated invasive squamous cell carcinoma of the tonsillar region and a minimum of 3 years follow-up, managed at a tertiary referral care center during the years 1970 to 2002, with an ipsilateral superiorly based SCMF flap after composite resection. The surgical procedure is presented in detail. Potential technical pitfalls are highlighted. Survival, mortality, and morbidity are documented. Univariate analysis for potential correlation between the incidence for postoperative flap complications and various variables is also performed. The 1, 3, and 5 year Kaplan-Meier actuarial survival estimates were 82.2%, 64.4%, and 49.3%, respectively. Death never appeared to be related to the completion of the SCMF flap. Thirty-three (45.2%) patients had some kind of significant postoperative surgical complication, and nine (12.3%) patients had some kind of significant postoperative medical complication. The most common significant postoperative complication was partial SCMF flap necrosis and pharyngocutaneous fistula noted in 30.1% and 10.9% of patients, respectively. Complete SCMF flap necrosis was never encountered. No patient developed carotid artery rupture or died as a result of the SCMF flap, and none required additional surgery. In univariate analysis, no significant statistical relation was noted between the significant postoperative surgical complications related to the use of the SCMF flap and the variables under analysis. The superiorly based SCMF flap appears to be simple to perform and useful for reconstruction of defects after composite resection.

Prefabricated Cervical Skin Flaps for Hemi-Facial Resurfacing: Elucidating the Natural History of Postoperative Edema Using Indocyanine Green.

PubMed

Li, Ke; Min, Peiru; Sadigh, Parviz; Grassetti, Luca; Lazzeri, Davide; Torresetti, Matteo; Marsili, Riccardo; Feng, Shaoqing; Liu, Ningfei; Zhang, Yi Xin

2018-02-01

The increases in capillary wall permeability and capillary hydrostatic pressure are considered to be the causes for the acute swelling seen in flaps; however, disruption of the circulating flap lymphatics could be another contributory factor. In this study we monitor the development of flap edema in a series of 18 prefabricated flaps and aim to delineate the natural history of this phenomenon by use of lymphography. Postoperative swelling was monitored in a series of 18 pre-expanded prefabricated cervical skin flaps used for hemi-facial burns-scar resurfacing. Time to spontaneous resolution, presence or absence of venous congestion, and clinical outcome were recorded. In two cases, indocyanine-green (ICG) lymphography was used to monitor the dermal backflow pattern until swelling had completely resolved. Average moving velocity of ICG after injection as well as flap thickness was also recorded over the follow-up period. The average moving velocity of ICG in the flap lymphatics improved from 0.48 cm/min to 1.5 cm/min in the first 12 days after flap transfer. The dermal backflow pattern was stardust in the first 12 days, indicating moderate lymphedema, transforming to splash from week three, and a robust collecting lymphatic vessel occurring from the fifth month, indicating mild lymphedema and lymphatic channel recovery, respectively. Transient swelling was observed in all prefabricated flaps in our series. We postulate that this is mostly secondary to lymphatic disruption that subsides as lymphangiogenesis takes place. ICG lymphography is an inexpensive, safe, and easy-to-use imaging technology that could be used in the monitoring of postoperative lymphedema seen in prefabricated flaps.

The Effects of Blowing Over Various Trailing-edge Flaps on an NACA 0006 Airfoil Section, Comparisons with Various Types of Flaps on other Airfoil Sections, and an Analysis of Flow and Power Relationships for Blowing Systems

NASA Technical Reports Server (NTRS)

Dods, J. B., Jr.; Watson, E. C.

1976-01-01

The results are presented of a two-dimensional investigation conducted to determine the effect of blowing over various types of trailing-edge flaps on a wing having the NACA 0006 airfoil section and a drooped-nose flap. The position and profile of the trailing-edge flap, the nozzle height, and the location of the flap with respect to the nozzle were found to be important variables. Data from many investigations were used to make an evaluation of the effects of blowing on lift. An analysis was made of flow and power relationships for blowing systems.

Use of the pericranial flap in medial canthal reconstruction: another application for this versatile flap.

PubMed

Leatherbarrow, Brian; Watson, Adam; Wilcsek, Geoffrey

2006-01-01

To describe the use and outcomes of a versatile surgical technique in the reconstruction of deep soft tissue and bony defects of the medial canthus. A retrospective review of consecutive cases requiring reconstruction of medial canthal defects involving loss of periosteum or bone by a median forehead pericranial flap and full-thickness skin grafting in a tertiary referral hospital setting. Two techniques were used: an open technique, using a midline forehead incision; and an endoscopic technique, using 2 incisions behind the hairline. Twenty-one cases were identified: 19 open and 2 endoscopic. The average length of follow-up was 13 months (range, 6-50 months). Ten cases required additional oculoplastic procedures including local periosteal flaps and mucous membrane grafts. Two cases (10%) had complete flap failure; one of these was caused by infection. Five (24%) had partial (< 50%) skin graft necrosis. Two cases (10%) have required further surgery. Our experience shows the pericranial flap to be versatile, robust, and easy to manipulate, offering advantages over alternative techniques when used for the repair of deep medial canthal defects. It is a valuable reconstructive technique that can yield good cosmetic and functional results.

Using a cross-cheek anterolateral thigh flap for simultaneous correction of trismus and oral cancer.

PubMed

Chen, Chun-Chia; Wong, Tung-Yiu; Ou, Chun-Yen; Lee, Jing-Wei

2010-01-01

Oral cancers in association with trismus are commonly seen in clinical practice. Such a situation deserves special attention as it may complicate the tumour-ablative surgery and interfere with postoperative cancer surveillance. It follows that the simultaneous tackling of oral cancer and trismus should be pursued at any rate. In this presentation, a novel surgical approach using a cross-cheek anterolateral thigh (ALT) flap is introduced. With the special design in length, shape and orientation, this flap is capable of closing a wider defect area, sometimes extending across two functional regions (viz., posterior palate and trigonal area) without resort to two free flaps. As such, complex defects resulting from trismus release and tumour ablation can be readily repaired in a single stage. The advantages of such a technique include abundance in soft-tissue resources, proper flap quality and thickness, reliable blood supply, long and sizeable pedicle, ease in flap inset, need for only one recipient rather than two and the eradication of large area of mucosa that is predisposed to malignant transformation. The favourable outcome implicates that this innovative design could be a viable option in the management of such a clinical problem. Copyright (c) 2009. Published by Elsevier Ltd.

Pressure distributions on a rectangular aspect-ratio-6, slotted supercritical airfoil wing with externally blown flaps

NASA Technical Reports Server (NTRS)

Johnson, W. G., Jr.

1976-01-01

An investigation was made in the 5.18 m (17 ft) test section of the Langley 300 MPH 7 by 10 foot tunnel on a rectangular, aspect ratio 6 wing which had a slotted supercritical airfoil section and externally blown flaps. The 13 percent thick wing was fitted with two high lift flap systems: single slotted and double slotted. The designations single slotted and double slotted do not include the slot which exists near the trailing edge of the basic slotted supercritical airfoil. Tests were made over an angle of attack range of -6 deg to 20 deg and a thrust-coefficient range up to 1.94 for a free-stream dynamic pressure of 526.7 Pa (11.0 lb/sq ft). The results of the investigation are presented as curves and tabulations of the chordwise pressure distributions at the midsemispan station for the wing and each flap element.

Effect of intradermal human recombinant copper-zinc superoxide dismutase on random pattern flaps in rats.

PubMed

Schein, Ophir; Westreich, Melvyn; Shalom, Avshalom

2013-09-01

Studies have focused on enhancing flap viability using superoxide dismutase (SOD), but only a few used SOD from human origin, and most gave the compound systemically. We evaluated the ability of SOD to improve random skin flap survival using human recombinant copper-zinc superoxide dismutase (Hr-CuZnSOD) in variable doses, injected intradermally into the flap. Seventy male Sprague Dawley rats were randomly assigned into 4 groups. Cephalic random pattern flaps were elevated on their backs and intradermal injections of different dosages of Hr-CuZnSOD were given 15 minutes before surgery. Flap survival was evaluated by fluorescein fluorescence. Analysis of variance (ANOVA) and t test statistical analyses were performed. Flap survival in all treated groups was significantly better than in the controls. The beneficial effect of HR-CuZnSOD on flap survival is attained when it is given intradermally into the flap tissue. Theoretically, Hr-CuZnSOD delivered with local anesthetics used in flap elevation may be a valuable clinical tool. Copyright © 2012 Wiley Periodicals, Inc.

Numerical analysis of a variable camber rotor blade as a lift control device

NASA Technical Reports Server (NTRS)

Awani, A. O.; Stroub, R. H.

1984-01-01

A new rotor configuration called the variable camber rotor was numerically investigated as a lift control device. This rotor differs from a conventional (baseline) rotor only in the blade aft section. In this configuration, the aft section or flap is attached to the forward section by pin joint arrangement, and also connected to the rotor control system for the control of rotor thrust level and vectoring. Pilot action to the flap deflection controls rotor lift and tip path plane tilt. The drag due to flaps is presented and the theoretical result correlated with test data. The assessment of payoff for the variable camber rotor in comparison with conventional (baseline) rotor was examined in hover. The variable camber rotor is shown to increase hover power required by 1.35%, but such a minimal power penalty is not significant enough to be considered a negative result. In forward flight, the control needs of the variable camber rotor were evaluated.

Reconstruction of anterior auricular conchal defect after malignancy excision: revolving-door flap versus full-thickness skin graft.

PubMed

Dessy, Luca Andrea; Figus, Andrea; Fioramonti, Paolo; Mazzocchi, Marco; Scuderi, Nicolò

2010-05-01

Skin tumours of the anterior auricular concha are not uncommon. Wider excision and immediate reconstruction are required to reduce the risks of recurrence of the disease, cartilage infection and external ear distortion. Many surgical methods have been described for reconstruction of conchal defects. Post-auricular island flaps, such as the revolving-door (RD) flap, and full-thickness skin grafts (FTSGs) are the most-performed procedures. Although the RD flap has been fully described, it is not widely accepted and many surgeons, in their daily practice, prefer to use FTSG. It is a common experience that FTSGs are more subjected to centripetal contraction, decreasing the structural firmness of the conchal cavity and affecting functional and aesthetic outcomes. Furthermore, FTSGs are more prone to delay in wound healing due to the difficult access to this region that hinders adequate tie-over dressings. Between March 2003 and January 2007, 40 patients affected by T1 and T2 non-melanotic skin cancer and T1 melanoma of the anterior conchal surface of the external ear were included in a prospective study and randomly assigned to the RD reconstructed group or to the FTSG reconstructed group to investigate, compare and define advantages and disadvantages of both the techniques. Visual Analogue Scale (VAS) was used to evaluate the overall outcome and the colour and texture match. No flap or skin graft total loss was observed. Six patients (30%) showed partial failure of FTSG. The RD group demonstrated excellent cosmetic outcome, ideal colour match, adequate structure of external ear, projection and shape. Wilcoxon matched-pairs rank-sum test demonstrated statistically significant higher scores for the RD group compared to the FTSG group (p<0.0001). The RD harvesting technique is easy and quicker than the FTSG technique. RD flap should be considered as the first choice for reconstruction of anterior auricular conchal defects following wider excision of skin tumours. Copyright (c) 2009. Published by Elsevier Ltd.

Successful Excision of Gynecomastia with Nipple Repositioning Technique Utilizing the Dermoglandular Flap

PubMed Central

Motamed, Sadrollah; Hassanpour, Seyed Esmail; Moosavizadeh, Seyed Mehdi; Heidari, Ataollah; Rouientan, Abdoreza; Nazemian, Mahmood

2015-01-01

There are many surgical techniques for treating gynecomastia. We report a new surgical technique in an adolescent with fatty glandular gynecomastia grade III, who was referred from an endocrinologist to our clinic. We excised the gynecomastia with nipple repositioning utilizing the dermoglandular flap (about 1 cm thickness and 10 cm width). After one month, no complication was detected and the patient was satisfied with his new breasts. We suggest this technique for fatty glandular gynecomastia grade III. PMID:26284186

External tissue expansion for difficult wounds using a simple cost effective technique.

PubMed

Nandhagopal, Vijayaraghavan; Chittoria, Ravi Kumar; Mohapatra, Devi Prasad; Thiruvoth, Friji Meethale; Sivakumar, Dinesh Kumar; Ashokan, Arjun

2015-01-01

To study and discuss role of external tissue expansion and wound closure (ETEWC) technique using hooks and rubber bands. The present study is a retrospective analysis of nine cases of wounds of different aetiology where ETEWC technique was applied using hooks and rubber bands. All the wounds in the study healed completely without split thickness skin graft (SSG) or flap. ETEWC technique using hooks and rubber bands is a cost-effective technique which can be used for wound closure without SSG or flap.

Improving the colour match of free tissue transfers to the face with non-cultured autologous cellular spray--a case report on a chin reconstruction.

PubMed

Hivelin, M; MacIver, Colin; Heusse, J L; Atlan, M; Lantieri, L

2012-08-01

Animal bites can result in extensive avulsion injuries of the face justifying microsurgical replantation attempts. Reconstruction using local tissue harvesting increases the local morbidity while distant tissues can result in colour and skin texture mismatching. Skin grafting of the skin paddle by a split-thickness skin graft is a conventional approach to help overcome this problem. An 18-year-old patient was treated for a chin avulsion after a dog bite injury. The avulsed segment included the whole chin aesthetic unit and one-fifth of the lower lip. The segment was replanted on the inferior labial artery. The replantation failed and a reconstruction with a parascapular free flap was performed. Despite a debulking at 1 month, the aesthetic result had a poor colour match. The technique used to improve this was to de-epithelialise the skin and apply non-cultured autologous epidermal cells (NCAECs) 100 days after the reconstruction. The reconstruction was uneventful. At 3 months follow-up, the patient was able to purse her lips and had regained sensation. After 5 months, the free flap paddle was consistent in colour, pigmentation and texture with the surrounding skin. At 10 months, the patient's only complaint was residual firmness in her scar and flap. The long-term follow-up, over 23 months, confirmed the stability of the results. The use of an NCAEC spray to treat the dyschromia on a parascapular flap used for facial reconstruction is less invasive than split-thickness overgrafting and could extend the use of distant flaps that have been avoided due to poor colour match. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Routine closure of the donor site with a second dorsal metacarpal artery flap to avoid the use of a skin graft after harvest of a first dorsal metacarpal artery flap.

PubMed

Chi, Zhenglin; Lin, Damu; Chen, Yiheng; Xue, Jixin; Li, Shi; Chu, Tinggang; Li, Zhijie

2018-06-01

Closure of the donor site on the index finger after raising a first dorsal metacarpal artery (DMA) flap harvest is challenging. The conventional choice is to use a full-thickness skin graft. However, this procedure is associated with several complications and a second donor site to harvest the skin graft is inevitable. The aim of this study was to design a modified incision to allow harvest of a first DMA flap without skin graft. From 2015 to 2016, 18 patients with a soft tissue defect of the thumb had reconstruction of the defect using a first DMA flap. A modified incision was used and a relaying perforator flap pedicled on the second DMA was raised through the same incision to cover the donor site. Patient satisfaction, appearance of the injured hand, and the active range of motion (ROM) were assessed. The sensitivity was evaluated by the 2-point discrimination (2-PD) test. All flaps survived completely without complications. Good coverage was obtained with only one linear scar in the dorsum of the hand and no skin grafts. All patients recovered full range of movement in their fingers and regained sensitivity of the flaps. All patients were satisfied with their hand function according to the Michigan Hand Outcomes Questionnaire (MHQ). The mean cosmetic score for the appearance of the injured hand was 8.2 out of 10. Using our modified incision, it was possible to harvest a second DMA flap at the same time as a first DMA flap allowing simultaneous coverage of the donor defect on the index finger. This prevented the need for a skin graft with all of the associated disadvantages. Copyright © 2018. Published by Elsevier Ltd.

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function.

PubMed

Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

2011-01-01

To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. At 6 months, mean values for UDVA (logMAR) were -0.043 ± 0.668 and -0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications.

A prospective, contralateral comparison of photorefractive keratectomy (PRK) versus thin-flap LASIK: assessment of visual function

PubMed Central

Hatch, Bryndon B; Moshirfar, Majid; Ollerton, Andrew J; Sikder, Shameema; Mifflin, Mark D

2011-01-01

Purpose: To compare differences in visual acuity, contrast sensitivity, complications, and higher-order ocular aberrations (HOAs) in eyes with stable myopia undergoing either photo-refractive keratectomy (PRK) or thin-flap laser in situ keratomileusis (LASIK) (intended flap thickness of 90 μm) using the VISX Star S4 CustomVue excimer laser and the IntraLase FS60 femtosecond laser at 1, 3, and 6 months postoperatively. Methods: In this prospective, masked, and randomized pilot study, refractive surgery was performed contralaterally on 52 eyes: 26 with PRK and 26 with thin-flap LASIK. Primary outcome measures were uncorrected distance visual acuity (UDVA), corrected distance visual acuity (CDVA), contrast sensitivity, and complications. Results: At 6 months, mean values for UDVA (logMAR) were −0.043 ± 0.668 and −0.061 ± 0.099 in the PRK and thin-flap LASIK groups, respectively (n = 25, P = 0.466). UDVA of 20/20 or better was achieved in 96% of eyes undergoing PRK and 92% of eyes undergoing thin-flap LASIK, whereas 20/15 vision or better was achieved in 73% of eyes undergoing PRK and 72% of eyes undergoing thin-flap LASIK (P > 0.600). Significant differences were not found between treatment groups in contrast sensitivity (P ≥ 0.156) or CDVA (P = 0.800) at postoperative 6 months. Types of complications differed between groups, notably 35% of eyes in the thin-flap LASIK group experiencing complications, including microstriae and 2 flap tears. Conclusion: Under well-controlled surgical conditions, PRK and thin-flap LASIK refractive surgeries achieve similar results in visual acuity, contrast sensitivity, and induction of HOAs, with differences in experienced complications. PMID:21573091

[The sural medial perforator flap: Anatomical bases, surgical technique and indications in head and neck reconstruction].

PubMed

Struk, S; Schaff, J-B; Qassemyar, Q

2018-04-01

The medial sural artery perforator (MSAP) flap is defined as a thin cutaneo-adipose perforator flap harvested on the medial aspect of the leg. The aims of this study were to describe the anatomical basis as well as the surgical technique and discuss the indications in head and neck reconstructive surgery. We harvested 10 MSAP flap on 5 fresh cadavers. For each case, the number and the location of the perforators were recorded. For each flap, the length of pedicle, the diameter of source vessels and the thickness of the flap were studied. Finally, we performed a clinical application of a MSAP flap. A total of 23 perforators with a diameter superior than 1mm were dissected on 10 legs. The medial sural artery provided between 1 and 4 musculocutaneous perforators. Perforators were located in average at 10.3cm±2cm from the popliteal fossa and at 3.6cm±1cm from the median line of the calf. The mean pedicle length was 12.1cm±2.5cm. At its origin, the source artery diameter was 1.8mm±0.25mm and source veins diameters were 2.45mm±0.9mm in average. There was no complication in our clinical application. This study confirms the reliability of previous anatomical descriptions of the medial sural artery perforator flap. This flap was reported as thin and particularly adapted for oral cavity reconstruction and for facial or limb resurfacing. Sequelae might be reduced as compared to those of the radial forearm flap with comparable results. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Case Report Reconstruction of Exposed Ilium With Reverse Turnover Latissimus Dorsi Muscle Flap

PubMed Central

Hayashida, Kenji; Endo, Yoshie; Kamebuchi, Katsuhiko

2011-01-01

Objective: It is difficult to cover a large skin and soft tissue defect with exposure of the ilium. We therefore performed a new reconstruction technique, using a reverse latissimus dorsi muscle flap fed by perforating branches of only the 10th intercostal artery. Methods: A 45-year-old man had a large traumatic defect located on the hip with exposure of the iliac crest. After confirming and preserving perforating branches of the 10th intercostal artery, the latissimus dorsi muscle flap was turned over just proximal to the perforating branch, and a split-thickness skin graft was performed over the flap. Results: The skin graft took place well and there were no circulation problems. Conclusions: This flap covered a larger area on the hip than the musculocutaneous flap. Furthermore, this is easier to perform and is less invasive than a vascularized free flap. Skin and soft tissue defects that expose bones of the lumbar or hip region can be reconstructed with a local flap; however, the deficit is small for this coverage and usually there is little skin and soft tissue to cover the wound defect in the surrounding area. Thus, it is often difficult to deal with large defects. We performed a reconstruction, using a reverse latissimus dorsi flap fed by perforating branches of the 10th intercostal artery for a large skin and soft tissue defect of the hip with exposure of the iliac crest, resulting in a good outcome. This technique is thought to be useful for reconstruction when the ilium is exposed, and we report the case and surgical procedure. PMID:21559059

Expanded Transposition Flap Technique for Total and Subtotal Resurfacing of the Face and Neck

PubMed Central

Spence, Robert J.

2007-01-01

Background: The reconstruction of major burn and other deformities resulting from significant soft tissue deficits of the face and neck is a continuing challenge for surgeons who wish to reliably restore facial function and aesthetic appearance. A primary problem is deficiency of well-matched donor skin. Other problems include the unique characteristics of facial skin, the fine anatomic nuances, and the unique functional demands placed on the face. This article describes an expanded shoulder transposition flap that can provide a large amount of both flap and full-thickness skin graft for total and subtotal reconstruction of the face. Methods: An expanded shoulder transposition flap has been used since 1986 for head and neck resurfacing 58 times in 41 patients ranging in age from 2 to 62 years. The details of the technique and the results of the flap including complications are described. Results: The flap proved remarkably reliable and reproducible in resurfacing the peripheral facial aesthetic units. The pedicle skin is often used for grafting of the central face with its finer features. The donor site of the flap is closed primarily. Conclusions: Twenty years' experience with expanded transposition flaps has shown it to be reliable and versatile in the reconstruction of major soft tissue deficits of the face and neck. It is a technique that provides economy of tissue, versatility, and is well within the skill, patience, and courage of most reconstructive surgeons. PMID:17534420

V-Y and rotation flap for reconstruction of the epicanthal fold.

PubMed

Shin, Yong Ho; Hwang, Pil Joong; Hwang, Kun

2012-07-01

Epicanthoplasty is commonly performed on Asian eyelids. Consequently, overcorrection may appear. The aim of this study was to introduce a method of reconstructing the epicanthal fold and to apply this method to the patients. A V flap with an extension (eagle beak shaped) was designed on the medial canthal area. The upper incision line started near the medial end of the double-fold line, and it followed its curvature inferomedially. For the lower incision, starting at the tip (medial end) of the flap, a curvilinear incision was designed first diagonally and then horizontally along the lower blepharoplasty line. The V flap was elevated as thin as possible. Then, the upper flap was deeply undermined to make it thick. The lower flap was made a little thinner than the upper flap. Then, the upper and lower flaps were approximated to form the anteromedial surface of the epicanthal fold in a fashion sufficient to cover the red caruncle. The V flap was rotated inferolaterally over the caruncle. The tip of the V flap was sutured to the medial one-third point of the lower margin. The inferior border of the V flap and the residual lower margin were approximated. Thereafter, the posterolateral surface of the epicanthal fold was made. From 1999 to 2011, 246 patients were operated on using this method. Among them, 62 patients were followed up. The mean intercanthal distance was increased from 31.7 to 33.8 mm postoperatively. Among the 246 patients operated on, reoperation was performed for 6 patients. Among the 6 patients reoperated on, 3 cases were due to epicanthus inversus, 1 case was due to insufficient reconstruction, 1 case was due to making an infold, and 1 case was due to reopening the epicanthal fold.This V-Y and rotation flap can be a useful method for reconstruction of the epicanthal fold.

Analysis of high-aspect-ratio jet-flap wings of arbitrary geometry

NASA Technical Reports Server (NTRS)

Lissaman, P. B. S.

1973-01-01

An analytical technique to compute the performance of an arbitrary jet-flapped wing is developed. The solution technique is based on the method of Maskell and Spence in which the well-known lifting-line approach is coupled with an auxiliary equation providing the extra function needed in jet-flap theory. The present method is generalized to handle straight, uncambered wings of arbitrary planform, twist, and blowing (including unsymmetrical cases). An analytical procedure is developed for continuous variations in the above geometric data with special functions to exactly treat discontinuities in any of the geometric and blowing data. A rational theory for the effect of finite wing thickness is introduced as well as simplified concepts of effective aspect ratio for rapid estimation of performance.

Static and wind tunnel model tests for the development of externally blown flap noise reduction techniques

NASA Technical Reports Server (NTRS)

Pennock, A. P.; Swift, G.; Marbert, J. A.

1975-01-01

Externally blown flap models were tested for noise and performance at one-fifth scale in a static facility and at one-tenth scale in a large acoustically-treated wind tunnel. The static tests covered two flap designs, conical and ejector nozzles, third-flap noise-reduction treatments, internal blowing, and flap/nozzle geometry variations. The wind tunnel variables were triple-slotted or single-slotted flaps, sweep angle, and solid or perforated third flap. The static test program showed the following noise reductions at takeoff: 1.5 PNdB due to treating the third flap; 0.5 PNdB due to blowing from the third flap; 6 PNdB at flyover and 4.5 PNdB in the critical sideline plane (30 deg elevation) due to installation of the ejector nozzle. The wind tunnel program showed a reduction of 2 PNdB in the sideline plane due to a forward speed of 43.8 m/s (85 kn). The best combination of noise reduction concepts reduced the sideline noise of the reference aircraft at constant field length by 4 PNdB.

A comparison of two implant techniques on patient-based outcome measures: a report of flapless vs. conventional flapped implant placement.

PubMed

Lindeboom, Jerome A; van Wijk, Arjen J

2010-04-01

Flapless implant surgery is considered to offer advantages over the traditional flap access approach. There may be minimized bleeding, decreased surgical times and minimal patient discomfort. Controlled studies comparing patient outcome variables to support these assumptions, however, are lacking. The objective of this clinical study was to compare patient outcome variables using flapless and flapped implant surgical techniques. From January 2008 to October 2008, 16 consecutive patients with edentulous maxillas were included in the study. Patients were randomly allocated to either implant placement with a flapless procedure (eight patients, mean age 54.6 + or - 2.9 years) or surgery with a conventional flap procedure (eight patients, mean age 58.7 + or - 7.2 years). All implants were placed using a Nobel guide CT-guided surgical template. Outcome measures were the Dutch version of the Impact of Event Scale-Revised (IES-R), dental anxiety using the s-DAI and oral health-related quality of life (OHIP-14). Ninety-six implants were successfully placed. All implants were placed as two-phase implants and the after-implant placement dentures were adapted. No differences could be shown between conditions on dental anxiety (s-DAI), emotional impact (IES-R), anxiety, procedure duration or technical difficulty, although the flapless group did score consistently higher. The flap procedure group reported less impact on quality of life and included more patients who reported feeling no pain at all during placement. Differences found in the patient outcome variables do suggest that patients in the flapless implant group had to endure more than patients in the flap group.

Static and Dynamic Aeroelastic Tailoring With Variable Camber Control

NASA Technical Reports Server (NTRS)

Stanford, Bret K.

2016-01-01

This paper examines the use of a Variable Camber Continuous Trailing Edge Flap (VCCTEF) system for aeroservoelastic optimization of a transport wingbox. The quasisteady and unsteady motions of the flap system are utilized as design variables, along with patch-level structural variables, towards minimizing wingbox weight via maneuver load alleviation and active flutter suppression. The resulting system is, in general, very successful at removing structural weight in a feasible manner. Limitations to this success are imposed by including load cases where the VCCTEF system is not active (open-loop) in the optimization process, and also by including actuator operating cost constraints.

Clinical Comparison of Full and Partial Double Pedicle Flaps with Connective Tissue Grafts for Treatment of Gingival Recession

PubMed Central

Ranjbari, Ardeshir; Gholami, Gholam Ali; Amid, Reza; Kadkhodazadeh, Mahdi; Youssefi, Navid; Mehdizadeh, Amir Reza; Aghaloo, Maryam

2016-01-01

Statement of the Problem Gingival recession has been considered as the most challenging issue in the field of periodontal plastic surgery. Purpose The purpose of this study was to evaluate the clinical efficacy of root coverage procedures by using partial thickness double pedicle graft and compare it with full thickness double pedicle graft. Materials and Method Eight patients, aged 15 to 58 years including 6 females and 2 males with 20 paired (mirror image) defects with class I and II gingival recession were randomly assigned into two groups. Clinical parameters such as recession depth, recession width, clinical attachment level, probing depth, and width of keratinized tissue were measured at the baseline and 6 months post-surgery. A mucosal double papillary flap was elevated and the respective root was thoroughly planed. The connective tissue graft was harvested from the palate, and then adapted over the root. The pedicle flap was secured over the connective tissue graft and sutured. The surgical technique was similar in the control group except for the prepared double pedicle graft which was full thickness. Results The mean root coverage was 88.14% (2.83 mm) in the test group and 85.7% (2.75 mm) in the control group. No statistical differences were found in the mean reduction of vertical recession, width of recession, or probing depth between the test and control groups. In both procedures, the width of keratinized tissue increased after three months and the difference between the two groups was not statistically significant in this respect. Conclusion Connective tissue with partial and full thickness double pedicle grafts can be successfully used for treatment of marginal gingival recession. PMID:27602394

Sutureless Corneal Transplantation Apparatus And Method

DOEpatents

Rowsey, J. James

1996-12-17

An eye with a cornea repaired without sutures comprising a donor material in the shape of a partial sphere having a generally central extent, the central extent being of the size and shape of the central portion of a cornea of an eye, the central extent having a periphery of a fixed diameter with an exterior surface in a convex configuration and an interior surface in a concave configuration and with an essentially common thickness throughout, the central extent having a plurality of corneal flaps extending radially from the periphery of the central extent, the flaps having exterior surfaces as a continuation of the exterior surface of the central extent; and a recipient eye in the shape of a partial sphere having a circular aperture in the cornea at its central portion, the central aperture being of a size and shape essentially that of the periphery of the central extent of the donor material, the aperture being of a common thickness at the periphery of the aperture, the central portion having pockets and with the central extent of the donor material located within the aperture of the recipient eye and with the flaps of the central extent being imbricated into the pockets of the recipient eye.

Femtosecond lasers for laser in situ keratomileusis: a systematic review and meta-analysis

PubMed Central

Huhtala, Anne; Pietilä, Juhani; Mäkinen, Petri; Uusitalo, Hannu

2016-01-01

Purpose The aim of this study was to review and meta-analyze whether there are differences between reported femtosecond (FS) lasers for laser-assisted in situ keratomileusis (LASIK) in terms of efficacy, predictability, and safety as primary outcomes and corneal flap thickness measurements and pre- and postoperative complications as secondary outcomes. Methods A comprehensive literature search of PubMed, Science Direct, Scopus, and Cochrane CENTRAL Trials Library databases was conducted to identify the relevant prospective randomized controlled trials of FS lasers for LASIK. Thirty-one articles describing a total of 5,404 eyes were included. Results Based on efficacy, IntraLase FS 10 and 30 kHz gave the best results. Based on predictability and safety, there were no differences between various FS lasers. FEMTO LDV and IntraLase FS 60 kHz produced the most accurate flap thicknesses. IntraLase and Wavelight SF200 had the fewest intraoperative complications. IntraLase, Visumax, and Wavelight FS200 had the most seldom postoperative complications. Conclusion There were dissimilarities between different FS lasers based on efficacy and intraoperative and postoperative complications. All FS lasers were predictable and safe for making corneal flaps in LASIK. PMID:27022236

Femtosecond lasers for laser in situ keratomileusis: a systematic review and meta-analysis.

PubMed

Huhtala, Anne; Pietilä, Juhani; Mäkinen, Petri; Uusitalo, Hannu

2016-01-01

The aim of this study was to review and meta-analyze whether there are differences between reported femtosecond (FS) lasers for laser-assisted in situ keratomileusis (LASIK) in terms of efficacy, predictability, and safety as primary outcomes and corneal flap thickness measurements and pre- and postoperative complications as secondary outcomes. A comprehensive literature search of PubMed, Science Direct, Scopus, and Cochrane CENTRAL Trials Library databases was conducted to identify the relevant prospective randomized controlled trials of FS lasers for LASIK. Thirty-one articles describing a total of 5,404 eyes were included. Based on efficacy, IntraLase FS 10 and 30 kHz gave the best results. Based on predictability and safety, there were no differences between various FS lasers. FEMTO LDV and IntraLase FS 60 kHz produced the most accurate flap thicknesses. IntraLase and Wavelight SF200 had the fewest intraoperative complications. IntraLase, Visumax, and Wavelight FS200 had the most seldom postoperative complications. There were dissimilarities between different FS lasers based on efficacy and intraoperative and postoperative complications. All FS lasers were predictable and safe for making corneal flaps in LASIK.

Comparison of the Multidetector-row Computed Tomographic Angiography Axial and Coronal Planes' Usefulness for Detecting Thoracodorsal Artery Perforators

PubMed Central

Kim, Jong Gyu

2012-01-01

Background During the planning of a thoracodorsal artery perforator (TDAP) free flap, preoperative multidetector-row computed tomographic (MDCT) angiography is valuable for predicting the locations of perforators. However, CT-based perforator mapping of the thoracodorsal artery is not easy because of its small diameter. Thus, we evaluated 1-mm-thick MDCT images in multiple planes to search for reliable perforators accurately. Methods Between July 2010 and October 2011, 19 consecutive patients (13 males, 6 females) who underwent MDCT prior to TDAP free flap operations were enrolled in this study. Patients ranged in age from 10 to 75 years (mean, 39.3 years). MDCT images were acquired at a thickness of 1 mm in the axial, coronal, and sagittal planes. Results The thoracodorsal artery perforators were detected in all 19 cases. The reliable perforators originating from the descending branch were found in 14 cases, of which 6 had transverse branches. The former were well identified in the coronal view, and the latter in the axial view. The location of the most reliable perforators on MDCT images corresponded well with the surgical findings. Conclusions Though MDCT has been widely used in performing the abdominal perforator free flap for detecting reliable perforating vessels, it is not popular in the TDAP free flap. The results of this study suggest that multiple planes of MDCT may increase the probability of detecting the most reliable perforators, along with decreasing the probability of missing available vessels. PMID:22872839

Factors Influencing Intraocular Pressure Changes after Laser In Situ Keratomileusis with Flaps Created by Femtosecond Laser or Mechanical Microkeratome.

PubMed

Lin, Meng-Yin; Chang, David C K; Shen, Yun-Dun; Lin, Yen-Kuang; Lin, Chang-Ping; Wang, I-Jong

2016-01-01

The aim of this study is to describe factors that influence the measured intraocular pressure (IOP) change and to develop a predictive model after myopic laser in situ keratomileusis (LASIK) with a femtosecond (FS) laser or a microkeratome (MK). We retrospectively reviewed preoperative, intraoperative, and 12-month postoperative medical records in 2485 eyes of 1309 patients who underwent LASIK with an FS laser or an MK for myopia and myopic astigmatism. Data were extracted, such as preoperative age, sex, IOP, manifest spherical equivalent (MSE), central corneal keratometry (CCK), central corneal thickness (CCT), and intended flap thickness and postoperative IOP (postIOP) at 1, 6 and 12 months. Linear mixed model (LMM) and multivariate linear regression (MLR) method were used for data analysis. In both models, the preoperative CCT and ablation depth had significant effects on predicting IOP changes in the FS and MK groups. The intended flap thickness was a significant predictor only in the FS laser group (P < .0001 in both models). In the FS group, LMM and MLR could respectively explain 47.00% and 18.91% of the variation of postoperative IOP underestimation (R2 = 0.47 and R(2) = 0.1891). In the MK group, LMM and MLR could explain 37.79% and 19.13% of the variation of IOP underestimation (R(2) = 0.3779 and 0.1913 respectively). The best-fit model for prediction of IOP changes was the LMM in LASIK with an FS laser.

Factors Influencing Intraocular Pressure Changes after Laser In Situ Keratomileusis with Flaps Created by Femtosecond Laser or Mechanical Microkeratome

PubMed Central

Lin, Meng-Yin; Chang, David C. K.; Shen, Yun-Dun; Lin, Yen-Kuang; Lin, Chang-Ping; Wang, I-Jong

2016-01-01

The aim of this study is to describe factors that influence the measured intraocular pressure (IOP) change and to develop a predictive model after myopic laser in situ keratomileusis (LASIK) with a femtosecond (FS) laser or a microkeratome (MK). We retrospectively reviewed preoperative, intraoperative, and 12-month postoperative medical records in 2485 eyes of 1309 patients who underwent LASIK with an FS laser or an MK for myopia and myopic astigmatism. Data were extracted, such as preoperative age, sex, IOP, manifest spherical equivalent (MSE), central corneal keratometry (CCK), central corneal thickness (CCT), and intended flap thickness and postoperative IOP (postIOP) at 1, 6 and 12 months. Linear mixed model (LMM) and multivariate linear regression (MLR) method were used for data analysis. In both models, the preoperative CCT and ablation depth had significant effects on predicting IOP changes in the FS and MK groups. The intended flap thickness was a significant predictor only in the FS laser group (P < .0001 in both models). In the FS group, LMM and MLR could respectively explain 47.00% and 18.91% of the variation of postoperative IOP underestimation (R2 = 0.47 and R2 = 0.1891). In the MK group, LMM and MLR could explain 37.79% and 19.13% of the variation of IOP underestimation (R2 = 0.3779 and 0.1913 respectively). The best-fit model for prediction of IOP changes was the LMM in LASIK with an FS laser. PMID:26824754

Feasibility of Human Skin Grafts on An Isolated But Accessible Vascular Supply on Athymic Rats As a System to Study Percutaneous Penetration and Cutaneous Injury

DTIC Science & Technology

1986-06-01

percutaneous toxicity, microcirculation of skin, nude rat 20. A.LSTICIACT (Carfrguje .r r *fd It n~e"ary7 d dn"fI b , block nyrnbor) ~Te bjctve of this researc...significant differences. An..iysis of the blood flow to the flap as a function of flap age , as well as the effect of cyclosporine, demonstrated that the...particular flap on a week to week basis. This was not related to administration of cyclosporine, body temperature, or age of the flap. The variability

Creation of a Bioengineered Skin Flap Scaffold with a Perfusable Vascular Pedicle.

PubMed

Jank, Bernhard J; Goverman, Jeremy; Guyette, Jacques P; Charest, Jon M; Randolph, Mark; Gaudette, Glenn R; Gershlak, Joshua R; Purschke, Martin; Javorsky, Emilia; Nazarian, Rosalynn M; Leonard, David A; Cetrulo, Curtis L; Austen, William G; Ott, Harald C

2017-07-01

Full-thickness skin loss is a challenging problem due to limited reconstructive options, demanding 75 million surgical procedures annually in the United States. Autologous skin grafting is the gold standard treatment, but results in donor-site morbidity and poor aesthetics. Numerous skin substitutes are available on the market to date, however, none truly functions as full-thickness skin due to lack of a vascular network. The creation of an autologous full-thickness skin analogue with a vascular pedicle would result in a paradigm shift in the management of wounds and in reconstruction of full-thickness skin defects. To create a clinically relevant foundation, we generated an acellular skin flap scaffold (SFS) with a perfusable vascular pedicle of clinically relevant size by perfusion decellularization of porcine fasciocutaneous flaps. We then analyzed the yielded SFS for mechanical properties, biocompatibility, and regenerative potential in vitro and in vivo. Furthermore, we assessed the immunological response using an in vivo model. Finally, we recellularized the vascular compartment of an SFS and reconnected it to a recipient's blood supply to test for perfusability. Perfusion decellularization removed all cellular components with preservation of native extracellular matrix composition and architecture. Biaxial testing revealed preserved mechanical properties. Immunologic response and biocompatibility assessed via implantation and compared with native xenogenic skin and commercially available dermal substitutes revealed rapid neovascularization and complete tissue integration. Composition of infiltrating immune cells showed no evidence of allorejection and resembled the inflammatory phase of wound healing. Implantation into full-thickness skin defects demonstrated good tissue integration and skin regeneration without cicatrization. We have developed a protocol for the generation of an SFS of clinically relevant size, containing a vascular pedicle, which can be utilized for perfusion decellularization and, ultimately, anastomosis to the recipient vascular system after precellularization. The observed favorable immunological response and good tissue integration indicate the substantial regenerative potential of this platform.

Reconstruction of the Foot and Ankle Using Pedicled or Free Flaps: Perioperative Flap Survival Analysis

PubMed Central

Li, Xiucun; Cui, Jianli; Maharjan, Suraj; Lu, Laijin; Gong, Xu

2016-01-01

Objective The purpose of this study is to determine the correlation between non-technical risk factors and the perioperative flap survival rate and to evaluate the choice of skin flap for the reconstruction of foot and ankle. Methods This was a clinical retrospective study. Nine variables were identified. The Kaplan-Meier method coupled with a log-rank test and a Cox regression model was used to predict the risk factors that influence the perioperative flap survival rate. The relationship between postoperative wound infection and risk factors was also analyzed using a logistic regression model. Results The overall flap survival rate was 85.42%. The necrosis rates of free flaps and pedicled flaps were 5.26% and 20.69%, respectively. According to the Cox regression model, flap type (hazard ratio [HR] = 2.592; 95% confidence interval [CI] (1.606, 4.184); P < 0.001) and postoperative wound infection (HR = 0.266; 95% CI (0.134, 0.529); P < 0.001) were found to be statistically significant risk factors associated with flap necrosis. Based on the logistic regression model, preoperative wound bed inflammation (odds ratio [OR] = 11.371,95% CI (3.117, 41.478), P < 0.001) was a statistically significant risk factor for postoperative wound infection. Conclusion Flap type and postoperative wound infection were both independent risk factors influencing the flap survival rate in the foot and ankle. However, postoperative wound infection was a risk factor for the pedicled flap but not for the free flap. Microvascular anastomosis is a major cause of free flap necrosis. To reconstruct complex or wide soft tissue defects of the foot or ankle, free flaps are safer and more reliable than pedicled flaps and should thus be the primary choice. PMID:27930679

Optimal placement of trailing-edge flaps for helicopter vibration reduction using response surface methods

NASA Astrophysics Data System (ADS)

Viswamurthy, S. R.; Ganguli, Ranjan

2007-03-01

This study aims to determine optimal locations of dual trailing-edge flaps to achieve minimum hub vibration levels in a helicopter, while incurring low penalty in terms of required trailing-edge flap control power. An aeroelastic analysis based on finite elements in space and time is used in conjunction with an optimal control algorithm to determine the flap time history for vibration minimization. The reduced hub vibration levels and required flap control power (due to flap motion) are the two objectives considered in this study and the flap locations along the blade are the design variables. It is found that second order polynomial response surfaces based on the central composite design of the theory of design of experiments describe both objectives adequately. Numerical studies for a four-bladed hingeless rotor show that both objectives are more sensitive to outboard flap location compared to the inboard flap location by an order of magnitude. Optimization results show a disjoint Pareto surface between the two objectives. Two interesting design points are obtained. The first design gives 77 percent vibration reduction from baseline conditions (no flap motion) with a 7 percent increase in flap power compared to the initial design. The second design yields 70 percent reduction in hub vibration with a 27 percent reduction in flap power from the initial design.

Characterization of Flap Edge Noise Radiation from a High-Fidelity Airframe Model

NASA Technical Reports Server (NTRS)

Humphreys, William M., Jr.; Khorrami, Mehdi R.; Lockard, David P.; Neuhart, Dan H.; Bahr, Christopher J.

2015-01-01

The results of an experimental study of the noise generated by a baseline high-fidelity airframe model are presented. The test campaign was conducted in the open-jet test section of the NASA Langley 14- by 22-foot Subsonic Tunnel on an 18%-scale, semi-span Gulfstream airframe model incorporating a trailing edge flap and main landing gear. Unsteady surface pressure measurements were obtained from a series of sensors positioned along the two flap edges, and far field acoustic measurements were obtained using a 97-microphone phased array that viewed the pressure side of the airframe. The DAMAS array deconvolution method was employed to determine the locations and strengths of relevant noise sources in the vicinity of the flap edges and the landing gear. A Coherent Output Power (COP) spectral method was used to couple the unsteady surface pressures measured along the flap edges with the phased array output. The results indicate that outboard flap edge noise is dominated by the flap bulb seal cavity with very strong COP coherence over an approximate model-scale frequency range of 1 to 5 kHz observed between the array output and those unsteady pressure sensors nearest the aft end of the cavity. An examination of experimental COP spectra for the inboard flap proved inconclusive, most likely due to a combination of coherence loss caused by decorrelation of acoustic waves propagating through the thick wind tunnel shear layer and contamination of the spectra by tunnel background noise at lower frequencies. Directivity measurements obtained from integration of DAMAS pressure-squared values over defined geometric zones around the model show that the baseline flap and landing gear are only moderately directional as a function of polar emission angle.

The Effectiveness at High Speeds of a 20-Percent-Chord Plain Trailing-Edge Flap on the NACA 65-210 Airfoil

NASA Technical Reports Server (NTRS)

Stivers, Louis S., Jr.

1947-01-01

An analysis has been made of the lift control effectiveness of a 20-percent-chord plain trailing-edge flap on the NACA 65-210 airfoil section from section lift-coefficient data obtained at Mach numbers from 0.3 to 0.875. In addition, the effectiveness of the plain flap as a lift-control device has been compared with the corresponding effectiveness of both a spoiler and a dive-recovery flap on the NACA 65-210 airfoil section. The analysis indicates that the plain trailing-edge flap employed on the 10-percent-thick airfoil at Mach numbers as high as 0.875 retains at least 50-percent of its low-speed lift-control effectiveness, and is sufficiently effective in lateral control application, assuming a rigid wing, to provide adequate airplane rolling characteristics. The plain trailing-edge flap, as compared to the spoiler and the dive-recovery flap, appears to afford the most favorable characteristics as a device for controlling lift continuously throughout the range of Mach numbers from 0.3 to 0.875. At Mach numbers above those for lift divergence of the wing, either a plain flap or a dive-recovery flap may be used on a thin airplane wing to provide auxiliary wing lift when the airplane is to be controlled in flight, other than in dives, at these Mach numbers. The choice of a lift-control device for this use, however, should include the consideration of other factors such as the increments of drag and pitching moment accompanying the use of the device, and the structural and high-speed aerodynamic characteristics of the airplane which is to employ the device.

Three-dimensional model simulation and reconstruction of composite total maxillectomy defects with fibula osteomyocutaneous flap flow-through from radial forearm flap.

PubMed

He, Yue; Zhu, Han Guang; Zhang, Zhi Yuan; He, Jie; Sader, Robert

2009-12-01

A total maxillectomy always causes composite defects of maxilla, zygomatic bone, orbital floor or rim, and palatal and nasal mucosa lining. This leads to significant functional and cosmetic consequences after ablative surgery. The purpose of this clinical study was to preliminarily 3-dimensionally reconstruct the defect of total maxillectomy with sufficient bone support and soft tissue lining. Three-dimensional model simulation technique and free fibula osteomyocutaneous flap flow-through from radial forearm flap were used to reconstruct a total maxillectomy defect for a 21-year-old female patient. Preoperatively, the 3-dimensional (3D) simulated resin models of skeleton and fibula were used to design the osteotomies and bone segment replacement. At surgery, a 22-cm-length free fibula was divided into 4 segments to make 1 maxilla skeletal framework in the schedule of the preoperative model surgical planning with a radial forearm flap flow-through for the free fibula flap with skin paddle to repair the palatal and nasal region. Free fibula and radial forearm flap were alive, and the patient was satisfied with the results both esthetically and functionally after dental rehabilitation which was carried out 6 months after surgery. This preliminarily clinical study and case demonstrated that: the fibula osteomyocutaneous flap is an ideal donor site in 3D total maxillectomy defect reconstruction, because of its thickness, length, and bone uniformity which makes ideal support for dental rehabilitation; the flow-through forearm radial flap not only serves as the vascular bridge to midface reconstruction, but also provides sufficient soft tissue cover for the intraoral defect; and the 3D model simulation and preoperative surgical planning are effective methods to refine reconstruction surgery, shorten the surgical time, and predict the outcome after operation.

Probe Without Moving Parts Measures Flow Angle

NASA Technical Reports Server (NTRS)

Corda, Stephen; Vachon, M. Jake

2003-01-01

The measurement of local flow angle is critical in many fluid-dynamic applications, including the aerodynamic flight testing of new aircraft and flight systems. Flight researchers at NASA Dryden Flight Research Center have recently developed, flight-tested, and patented the force-based flow-angle probe (FLAP), a novel, force-based instrument for the measurement of local flow direction. Containing no moving parts, the FLAP may provide greater simplicity, improved accuracy, and increased measurement access, relative to conventional moving vane-type flow-angle probes. Forces in the FLAP can be measured by various techniques, including those that involve conventional strain gauges (based on electrical resistance) and those that involve more advanced strain gauges (based on optical fibers). A correlation is used to convert force-measurement data to the local flow angle. The use of fiber optics will enable the construction of a miniature FLAP, leading to the possibility of flow measurement in very small or confined regions. This may also enable the tufting of a surface with miniature FLAPs, capable of quantitative flow-angle measurements, similar to attaching yarn tufts for qualitative measurements. The prototype FLAP was a small, aerodynamically shaped, low-aspect-ratio fin about 2 in. (approximately equal to 5 cm) long, 1 in. (approximately equal to 2.5 cm) wide, and 0.125 in. (approximately equal to 0.3 cm) thick (see Figure 1). The prototype FLAP included simple electrical-resistance strain gauges for measuring forces. Four strain gauges were mounted on the FLAP; two on the upper surface and two on the lower surface. The gauges were connected to form a full Wheatstone bridge, configured as a bending bridge. In preparation for a flight test, the prototype FLAP was mounted on the airdata boom of a flight-test fixture (FTF) on the NASA Dryden F-15B flight research airplane.

Tunnel technique with connective tissue graft versus coronally advanced flap with enamel matrix derivative for root coverage: a RCT using 3D digital measuring methods. Part II. Volumetric studies on healing dynamics and gingival dimensions.

PubMed

Rebele, Stephan F; Zuhr, Otto; Schneider, David; Jung, Ronny E; Hürzeler, Markus B

2014-06-01

The aim of this randomized clinical trial (RCT) was to compare the clinical performance of the tunnel technique with subepithelial connective tissue graft (TUN) versus a coronally advanced flap with enamel matrix derivative (CAF) in the treatment of gingival recession defects. The use of innovative 3D digital measuring methods allowed to study healing dynamics at connective tissue (CT)-grafted sites and to evaluate the influence of the thickness of the root covering soft tissues on the outcome of surgical root coverage. Twenty-four patients contributed a total of 47 Miller class I or II recessions for scientific evaluation. Precise study models collected at baseline and follow-up examinations were optically scanned and virtually superimposed for digital evaluation of clinical outcome measures including mean marginal soft tissue thickness (THK). Healing dynamics were measured in a defined region of interest at CT-grafted sites where volume differences between time points were calculated. At 12 months, recession reduction as well as mean root coverage were significantly better at CT-grafted sites treated in the TUN group (1.94 mm and 98.4% respectively) compared to the non-augmented sites of the CAF group (1.17 mm and 71.8% respectively) and statistical analysis revealed a positive correlation of THK (1.63 mm TUN versus 0.91 mm CAF, p < 0.0001) to both these variables. Soft tissue healing following surgical root coverage with CT-grafting was mainly accomplished after 6 months, with around two-thirds of the augmented volume being maintained after 12 months. The TUN resulted in thicker gingiva and better clinical outcomes compared to CAF. Increased gingival thickness was associated with better surgical outcomes in terms of recession reduction and root coverage. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Analogy between a flapping wing and a wind turbine with a vertical axis of revolution

NASA Astrophysics Data System (ADS)

Gorelov, D. N.

2009-03-01

Based on an analysis of available experimental data, the hypothesis about an analogy between a flapping wing and a wind turbine of the Darrieus rotor type is justified. It is demonstrated that the torque on the shaft of the Darrieus rotor is generated by thrust forces acting on the blades in a pulsed flow. A conclusion is drawn that it is necessary to perform aerodynamic calculations of blades on the basis of the nonlinear theory of the wing in an unsteady flow with allowance for the airfoil thickness.

Vertical Profunda Artery Perforator Flap for Plantar Foot Wound Closure: A New Application.

PubMed

Alfonso, Allyson R; Mayo, James L; Sharma, Vishal K; Allen, Robert J; Chiu, Ernest S

2018-02-01

Plantar foot reconstruction requires special consideration of both form and function. There are several fasciocutaneous flap options, each with indications and reservations. This case presents a new application of the vertical profunda artery perforator flap for definitive closure of a neuropathic foot ulcer in a young woman with spina bifida. The postoperative course was uneventful, and the flap survived completely. The surgical and donor sites were without wound recurrence at 5-month follow-up. Understanding the variability of foot flap options is important because of unique cases such as the one presented where the wound was caused by specific and less commonly observed foot anatomy. The specific choice to use the vertical profunda artery perforator flap for this patient and her neuropathic wound type was made based on its excellent flexibility, durability, and donor site appeal. The vertical profunda artery perforator flap has adequate surface area and bulk and a favorable pedicle length and caliber, can be thinned, and leaves a donor scar in a less conspicuous area than other popular free flaps for lower-extremity reconstruction. For these reasons, it should be considered a first-line therapy for free flap coverage of selected foot wounds.

Production frequency effects in perception of phonological variation

NASA Astrophysics Data System (ADS)

Connine, Cynthia M.; Ranbom, Larissa J.

2004-05-01

Two experiments were conducted that investigated the relationship between phonological variant occurrence frequency (based on a corpus analysis of conversational speech) and auditory word recognition. The variant investigated was an alternation between the presence of [nt] and a nasal flap (e.g., center, cen'er). The corpus analysis showed that 80% of productions are nasal flaps, with wide variability across words (from 0% for ``enter'' to 100% for ``twenty''). In a production goodness rating experiment, listeners rated [nt] productions as better than their nasal flap counterparts. For individual items, a strong positive correlation was found between nasal flap frequency and goodness ratings: words typically produced with nasal flaps were rated as better productions. A lexical decision experiment showed that nasal flap variants were recognized more slowly and less accurately than [nt] versions. The rated quality of the nasal-flapped production was strongly correlated with the results of the lexical decision task: nasal-flapped words considered highly acceptable were recognized more quickly and accurately than words rated as poor nasal flap productions. The results demonstrate a strong relationship between experienced variant frequency and auditory word recognition and suggest that phonological variation is explicitly represented in the mental lexicon.

Aerodynamic characteristics of the ventilated design for flapping wing micro air vehicle.

PubMed

Zhang, G Q; Yu, S C M

2014-01-01

Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the "ventilation" in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds.

Aerodynamic Characteristics of the Ventilated Design for Flapping Wing Micro Air Vehicle

PubMed Central

Zhang, G. Q.; Yu, S. C. M.

2014-01-01

Inspired by superior flight performance of natural flight masters like birds and insects and based on the ventilating flaps that can be opened and closed by the changing air pressure around the wing, a new flapping wing type has been proposed. It is known that the net lift force generated by a solid wing in a flapping cycle is nearly zero. However, for the case of the ventilated wing, results for the net lift force are positive which is due to the effect created by the “ventilation” in reducing negative lift force during the upstroke. The presence of moving flaps can serve as the variable in which, through careful control of the areas, a correlation with the decrease in negative lift can be generated. The corresponding aerodynamic characteristics have been investigated numerically by using different flapping frequencies and forward flight speeds. PMID:24683339

Static internal performance of a single expansion ramp nozzle with multiaxis thrust vectoring capability

NASA Technical Reports Server (NTRS)

Capone, Francis J.; Schirmer, Alberto W.

1993-01-01

An investigation was conducted at static conditions in order to determine the internal performance characteristics of a multiaxis thrust vectoring single expansion ramp nozzle. Yaw vectoring was achieved by deflecting yaw flaps in the nozzle sidewall into the nozzle exhaust flow. In order to eliminate any physical interference between the variable angle yaw flap deflected into the exhaust flow and the nozzle upper ramp and lower flap which were deflected for pitch vectoring, the downstream corners of both the nozzle ramp and lower flap were cut off to allow for up to 30 deg of yaw vectoring. The effects of nozzle upper ramp and lower flap cutout, yaw flap hinge line location and hinge inclination angle, sidewall containment, geometric pitch vector angle, and geometric yaw vector angle were studied. This investigation was conducted in the static-test facility of the Langley 16-Foot Transonic Tunnel at nozzle pressure ratios up to 8.0.

Reconstructive Surgery in the Thermally Injured Patient

DTIC Science & Technology

2012-01-01

Pedicle flaps • Reconstructive Surgery • Thermal injury • Z-plasties • Skin grafting AN INCREASED NEED FOR RECONSTRUCTIVE SURGERY Reconstruction is a...dermal structure and include the tendency for recurrent contractures. full-thickness skin graft s are usually reserved for reconstructions with...dermatologic surgery: review and update on full- and split thickness skin grafts , free cartilage grafts, and composite grafts. Dermatol Surg 2005;31

Correction of the bilateral question mark ear deformity using double-opposing z-plasty and a chondrocutaneous flap.

PubMed

Bastidas, Nicholas; Taylor, Jesse A

2013-03-01

To describe an alternative technique for correcting a rare and complex ear deformity. The question mark ear deformity has been described as a congenital cleft between the helix and the lobule in addition to a prominent ear. Here we describe a novel technique using double-opposing Z-plasty and a chondrocutaneous flap to correct the deformity without significant reduction in auricle height or creation of a donor-site defect. An anterior/posterior double-opposing Z-plasty and a superiorly based chondrocutaneous flap were designed at the level of the cleft. Flaps were raised full thickness, and Mustarde and Furnas sutures were placed to reduce the prominence. The flaps were then transposed and reapproximated. Of note, all anterior and posterior skin flaps were used in the repair to minimize diminution of ear height. Pre- and postoperative measurements and photographs of the ears were taken. Postoperatively, all flaps were viable, and there was no evidence of skin necrosis. The total length of the left ear was reduced by only 3 mm (53 to 50 mm), and the right ear was reduced by 1 mm (52 to 51 mm). The patient's pain was successfully managed as an outpatient, and there were no infectious complications. The resultant scars healed aesthetically and are minimally visible. The patient and her parents are satisfied with the results. Our technique addresses all components of the question mark ear deformity and does not create a visible donor-site deformity.

[DORSALIS PEDIS FLAP SERIES-PARALLEL BIG TOE NAIL COMPOSITE TISSUE FLAP TO REPAIR HAND SKIN OF DEGLOVING INJURY WITH THUMB DEFECT].

PubMed

Shi, Pengju; Zhang, Wenlong; Zhao, Gang; Li, Zhigang; Zhao, Shaoping; Zhang, Tieshan

2015-07-01

To investigate the effectiveness of dorsalis pedis flap series-parallel big toe nail composite tissue flap in the repairment of hand skin of degloving injury with tumb defect. Between March 2009 and June 2013, 8 cases of hand degloving injury with thumb defect caused by machine twisting were treated. There were 7 males and 1 female with the mean age of 36 years (range, 26-48 years). Injury located at the left hand in 3 cases and at the right hand in 5 cases. The time from injury to hospitalization was 1.5-4.0 hours (mean, 2.5 hours). The defect area was 8 cm x 6 cm to 15 cm x 1 cm. The thumb defect was rated as degree I in 5 cases and as degree II in 3 cases. The contralateral dorsal skin flap (9 cm x 7 cm to 10 cm x 8 cm) combined with ipsilateral big toe nail composite tissue flap (2.5 cm x 1.8 cm to 3.0 cm x 2.0 cm) was used, including 3 parallel anastomosis flaps and 5 series anastomosis flaps. The donor site of the dorsal flap was repaired with thick skin grafts, the stumps wound was covered with tongue flap at the shank side of big toe. Vascular crisis occurred in 1 big toe nail composite tissue flap, margin necrosis occurred in 2 dorsalis pedis flap; the other flaps survived, and primary healing of wound was obtained. The grafted skin at dorsal donor site all survived, skin of hallux toe stump had no necrosis. Eight cases were followed up 4-20 months (mean, 15.5 months). All flaps had soft texture and satisfactory appearance; the cutaneous sensory recovery time was 4-7 months (mean, 5 months). At 4 months after operation, the two-point discrimination of the thumb pulp was 8-10 mm (mean, 9 mm), and the two-point discrimination of dorsal skin flap was 7-9 mm (mean, 8.5 mm). According to Society of Hand Surgery standard for the evaluation of upper part of the function, the results were excellent in 4 cases, good in 3 cases, and fair in 1 case. The donor foot had normal function. Dorsalis pedis flap series-parallel big toe nail composite tissue flap is an ideal way to repair hand skin defect, and reconstructs the thumb, which has many advantages, including simple surgical procedure, no limitation to recipient site, soft texture, satisfactory appearance and function of reconstructing thumb, and small donor foot loss.

The plane problem of the flapping wing

NASA Technical Reports Server (NTRS)

Birnbaum, Walter

1954-01-01

In connection with an earlier report on the lifting vortex sheet which forms the basis of the following investigations this will show how the methods developed there are also suitable for dealing with the air forces for a wing with a circulation variable with time. The theory of a propulsive wing flapping up and down periodically in the manner of a bird's wing is developed. This study shows how the lift and its moment result as a function of the flapping motion, what thrust is attainable, and how high is the degree of efficiency of this flapping propulsion unit if the air friction is disregarded.

Magnitude of Myocutaneous Flaps and Factors Associated With Loss of Volume in Oral Cancer Reconstructive Surgery.

PubMed

Sakamoto, Yuki; Yanamoto, Souichi; Ota, Yoshihide; Furudoi, Shungo; Komori, Takahide; Umeda, Masahiro

2016-03-01

Myocutaneous flaps are often used to repair oral and maxillofacial defects after surgery for oral cancer; however, their volume decreases during the postoperative period. To facilitate treatment planning, the authors measured the extent of such postoperative flap volume loss and identified associated factors in patients who underwent oral reconstruction with myocutaneous flaps. The authors designed and performed a retrospective observational study of patients who underwent reconstructive procedures involving rectus abdominal myocutaneous (RAM) or pectoralis major myocutaneous (PMMC) flaps at Tokai University Hospital, Kobe University Hospital, or Nagasaki University Hospital from April 2009 through March 2013. Flap type and other clinical variables were examined as potential predictors of flap loss. The primary outcome was flap loss at 6 months postoperatively. Correlations between each potential predictor and the primary outcome were examined using multiple regression analysis. The subjects were 75 patients whose oral defects were reconstructed with RAM flaps (n = 57) or PMMC flaps (n = 18). RAM flaps exhibited a mean volume shrinkage of 22% at 6 months postoperatively, which was less than the 27.5% displayed by the PMMC flaps, but the difference was not important. Renal failure, previous surgery of the oral region, postoperative radiotherapy, and postoperative serum albumin level were found to be meaningful risk factors for postoperative flap volume loss. The results of this study suggest that larger flaps should be used in patients who possess these risk factors or are scheduled to undergo postoperative radiotherapy. Future studies should examine the utility of postoperative nutritional management for preventing flap volume loss. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Aerodynamic effects of flexibility in flapping wings.

PubMed

Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P

2010-03-06

Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re approximately 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small robotic insects and, to a limited extent, in understanding the aerodynamics of flapping insect wings.

Aerodynamic effects of flexibility in flapping wings

PubMed Central

Zhao, Liang; Huang, Qingfeng; Deng, Xinyan; Sane, Sanjay P.

2010-01-01

Recent work on the aerodynamics of flapping flight reveals fundamental differences in the mechanisms of aerodynamic force generation between fixed and flapping wings. When fixed wings translate at high angles of attack, they periodically generate and shed leading and trailing edge vortices as reflected in their fluctuating aerodynamic force traces and associated flow visualization. In contrast, wings flapping at high angles of attack generate stable leading edge vorticity, which persists throughout the duration of the stroke and enhances mean aerodynamic forces. Here, we show that aerodynamic forces can be controlled by altering the trailing edge flexibility of a flapping wing. We used a dynamically scaled mechanical model of flapping flight (Re ≈ 2000) to measure the aerodynamic forces on flapping wings of variable flexural stiffness (EI). For low to medium angles of attack, as flexibility of the wing increases, its ability to generate aerodynamic forces decreases monotonically but its lift-to-drag ratios remain approximately constant. The instantaneous force traces reveal no major differences in the underlying modes of force generation for flexible and rigid wings, but the magnitude of force, the angle of net force vector and centre of pressure all vary systematically with wing flexibility. Even a rudimentary framework of wing veins is sufficient to restore the ability of flexible wings to generate forces at near-rigid values. Thus, the magnitude of force generation can be controlled by modulating the trailing edge flexibility and thereby controlling the magnitude of the leading edge vorticity. To characterize this, we have generated a detailed database of aerodynamic forces as a function of several variables including material properties, kinematics, aerodynamic forces and centre of pressure, which can also be used to help validate computational models of aeroelastic flapping wings. These experiments will also be useful for wing design for small robotic insects and, to a limited extent, in understanding the aerodynamics of flapping insect wings. PMID:19692394

Aesthetic Penoscrotal Resurfacing: Creating Propeller Flaps from Gluteal Folds.

PubMed

Han, So-Eun; Kim, Eun-Ji; Sung, Hyun Hwan; Pyon, Jai-Kyong

2018-04-01

Reconstruction of extensive penoscrotal defects is a surgical challenge. Resurfacing defects in highly complex three-dimensional structures and restoring their function are an essential part of the reconstruction of penoscrotal regions. We describe a technique using internal pudendal artery perforator (IPAP) pedicled propeller flaps created from the gluteal fold. This could be a reliable surgical option that maintains a natural looking scrotal pouch with minimal donor site morbidity and optimal sexual activity. We retrospectively reviewed data for 10 consecutive patients who had undergone penoscrotal reconstruction using IPAP pedicled propeller flaps between January 2011 and March 2015. The IPAP was identified using a hand-held Doppler ultrasound device. This was the pivot around which the flap was internally rotated more than 90° in a tension-free manner. The long axis of the flap was centred on the gluteal fold to provide a better-orientated donor site scar. Complications and patient satisfaction with respect to size, colour match, scar appearance, and sexual activity were evaluated. Anatomic and aesthetic penoscrotal reconstruction was performed without any major complications in the follow-up period (mean, 19.7 mo). The mean width of the IPAP pedicled propeller flaps was 6.7cm, and the mean length was 11.7cm. Partial distal flap necrosis occurred in only one case, and healed spontaneously. All of the patients were satisfied with the cosmetic and functional results. On the basis of reliable perforators, donor site morbidity, flap thickness, and a better orientated scar, our technique using IPAP pedicled propeller flaps created from the gluteal fold could be a reasonable surgical option for extensive penoscrotal reconstruction. The creation of pedicled propeller flaps using an internal pudendal artery perforator could be a reliable surgical option for reconstruction of extensive penoscrotal defects. The approach yields functional and aesthetically acceptable surgical results. Copyright © 2016. Published by Elsevier B.V.

Magnetic configurations of the tilted current sheets in magnetotail

NASA Astrophysics Data System (ADS)

Shen, C.; Rong, Z. J.; Li, X.; Dunlop, M.; Liu, Z. X.; Malova, H. V.; Lucek, E.; Carr, C.

2008-11-01

In this research, the geometrical structures of tilted current sheet and tail flapping waves have been analysed based on multiple spacecraft measurements and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1) The magnetic field lines (MFLs) in the tilted current sheet are generally plane curves and the osculating planes in which the MFLs lie are about vertical to the equatorial plane, while the normal of the tilted current sheet leans severely to the dawn or dusk side. (2) The tilted current sheet may become very thin, the half thickness of its neutral sheet is generally much less than the minimum radius of the curvature of the MFLs. (3) In the neutral sheet, the field-aligned current density becomes very large and has a maximum value at the center of the current sheet. (4) In some cases, the current density is a bifurcated one, and the two humps of the current density often superpose two peaks in the gradient of magnetic strength, indicating that the magnetic gradient drift current is possibly responsible for the formation of the two humps of the current density in some tilted current sheets. Tilted current sheets often appear along with tail current sheet flapping waves. It is found that, in the tail flapping current sheets, the minimum curvature radius of the MFLs in the current sheet is rather large with values around 1 RE, while the neutral sheet may be very thin, with its half thickness being several tenths of RE. During the flapping waves, the current sheet is tilted substantially, and the maximum tilt angle is generally larger than 45°. The phase velocities of these flapping waves are several tens km/s, while their periods and wavelengths are several tens of minutes, and several earth radii, respectively. These tail flapping events generally last several hours and occur during quiet periods or periods of weak magnetospheric activity.

Chest wall reconstruction using iliac bone allografts and muscle flaps.

PubMed

Garcia-Tutor, Emilio; Yeste, Luis; Murillo, Julio; Aubá, Cristina; Sanjulian, Mikel; Torre, Wenceslao

2004-01-01

Technically we can divide full-thickness thoracic reconstruction into 2 parts: providing a rigid support and ensuring well-vascularized coverage. Since 1986, the authors' center has had ample experience with bone banks and the use of cryopreserved bone grafts, which led them to consider the possibility of using these grafts for full-thickness chest wall reconstruction. They describe 3 patients in whom resection of the tumor and reconstruction of the thorax were carried out using iliac bone allografts covered with muscle flaps (1 pectoralis major and 2 rectus abdominis). None of the patients experienced breathing difficulties, pain, or instability after 14 months, 18 months, and 11 years of follow-up. The result of the reconstruction was excellent in all 3 patients in terms of function and aesthetics. The advantage of allografts compared with synthetic materials is their potential integration; they can become part of the host patient's living tissue.

The proximally based long peroneal muscle turnover flap: A novel salvage flap for small to medium-sized defects of the knee.

PubMed

Wagner, Till; Hupkens, Pieter; Slater, Nicholas J; Ulrich, Dietmar J O

2016-04-01

Coverage of soft-tissue defects of the knee due to multiple operations, trauma, and infection remains a surgical challenge. Often, these defects are repaired using free tissue transfer. The aim of this study was to find an easy and reliable local method of repair for small to medium-sized defects. The authors describe a new surgical option for tissue coverage using a proximally based long peroneal muscle turnover flap (LPTF) with split-thickness skin graft. Proximally based LPTFs were harvested and transposed into same-size created defects in five cadavers. After optimizing this technique, it was clinically used in two patients with defects secondary to total knee replacement revisions. Average cadaver flap size was 4.7 × 15.8 cm allowing reach of all knee joint areas and was based consistently on a sufficient (2-mm-diameter average) proximal arterial branch of the anterior tibial artery. Donor sites were closed without tension. Subsequent application of the flap on two patients resulted in good functional outcome. The proximally based LPTF is a new option available in the reconstruction of knee defects and should be added to the reconstructive surgeon's armamentarium of pedicled flaps, providing short operating time and promising clinical outcome. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Relative Composition of Fibrous Connective and Fatty/Glandular Tissue in Connective Tissue Grafts Depends on the Harvesting Technique but not the Donor Site of the Hard Palate.

PubMed

Bertl, Kristina; Pifl, Markus; Hirtler, Lena; Rendl, Barbara; Nürnberger, Sylvia; Stavropoulos, Andreas; Ulm, Christian

2015-12-01

Whether the composition of palatal connective tissue grafts (CTGs) varies depending on donor site or harvesting technique in terms of relative amounts of fibrous connective tissue (CT) and fatty/glandular tissue (FGT) is currently unknown and is histologically assessed in the present study. In 10 fresh human cadavers, tissue samples were harvested in the anterior and posterior palate and in areas close to (marginal) and distant from (apical) the mucosal margin. Mucosal thickness, lamina propria thickness (defined as the extent of subepithelial portion of the biopsy containing ≤25% or ≤50% FGT), and proportions of CT and FGT were semi-automatically estimated for the entire mucosa and for CTGs virtually harvested by split-flap (SF) preparation minimum 1 mm deep or after deepithelialization (DE). Palatal mucosal thickness, ranging from 2.35 to 6.89 mm, and histologic composition showed high interindividual variability. Lamina propria thickness (P >0.21) and proportions of CT (P = 0.48) and FGT (P = 0.15) did not differ significantly among the donor sites (anterior, posterior, marginal, apical). However, thicker palatal tissue was associated with higher FGT content (P <0.01) and thinner lamina propria (P ≤0.03). Independent of the donor site, DE-harvested CTG contained a significantly higher proportion of CT and a lower proportion of FGT than an SF-harvested CTG (P <0.04). Despite high interindividual variability in terms of relative tissue composition in the hard palate, DE-harvested CTG contains much larger amounts of CT and much lower amounts of FGT than SF-harvested CTG, irrespective of the harvesting site.

[Aesthetic reconstruction strategy for postburn facial scar and its clinical effect].

PubMed

Ma, X J; Li, W Y; Liu, C H; Li, Y

2016-08-20

To explore the aesthetic reconstruction strategy for postburn facial scar and its clinical effect. Three hundred and forty-two patients with postburn facial scars were hospitalized from January 2000 to December 2015. Local expanded flap or deltopectoral expanded flap was used for reconstruction according to the location and size of the facial scar. The forehead expanded flap could be chosen for the scar in dorsum nasi or inferior eyelid. The local expanded flap was chosen when the scar width was smaller than 5 cm in cheek, chin, and marginal mandible region. The expanded deltopectoral flap was chosen when the scar width was larger than 5 cm in cheek, chin, and marginal mandible region or the scar contracture was too serious to cause displacement of lips, nose, or eyelid, and the wound width was larger than 5 cm after release. The facial scars of 82 patients, with size ranged from 6.0 cm×2.5 cm to 15.0 cm×10.0 cm, were reconstructed with expanded local flaps. The facial scars of 260 patients, with size ranged from 8.0 cm×7.0 cm to 38.0 cm×13.0 cm, were reconstructed with expanded deltopectoral flaps. After expansion of 2 to 6 months, the facial scars were excised and completely released first of all. The transfer way of local flap and size of deltopectoral flap with pedicle were designed according to the size and shape of the wound. Three weeks after transfer of deltopectoral flap, flap delay procedure was conducted. One week later, the pedicle was severed from the flap to reconstruct the remaining scar. Anti-scar medicine, laser therapy, and elasticized fabric were used postoperatively on the scars in both donor and recipient sites. During the postoperative follow-up for 3 to 12 months, the flaps of 40 out of 82 cases reconstructed with expanded local flaps were in good color and texture. Before 2008, mild scar hyperplasia was observed in the incision of 19 patients; with application of laser after 2008, the number of patients with scar hyperplasia was decreased. During the postoperative follow-up for 3 to 12 months, the flaps of 90 out of 260 cases reconstructed with expanded deltopectoral flaps were in good color and texture. The expander was exposed from the incision in 15 patients, while it did not affect the later treatment. Nine unilateral flaps showed poor blood circulation at the distal end, and they were healed after dressing change. In the early phase, necrosis was observed in one flap after transfer, and it was healed after transplantation of free skin graft. Scar hyperplasia was observed in the chest donor site of one patient, and it was improved after laser therapy. Postburn facial scar could be reconstructed with local or deltopectoral flaps, following the principle of similarity. The expansion could increase the size of the flaps, reduce the thickness of the flaps, and lower the donor site damage.

The myocutaneous trapezius flap revisited: a treatment algorithm for optimal surgical outcomes based on 43 flap reconstructions.

PubMed

Can, Anil; Orgill, Dennis P; Dietmar Ulrich, J O; Mureau, Marc A M

2014-12-01

Because the vascular anatomy of the trapezius flap is highly variable, choosing the most appropriate flap type and design is essential to optimize outcomes and minimize postoperative complications. The aim of this study was to develop a surgical treatment algorithm for trapezius flap transfers. The medical files of all consecutive patients with a myocutaneous trapezius flap reconstruction of the head, neck, and upper back area treated at three different university medical centers between July 2001 and November 2012 were reviewed. There were 43 consecutive flaps performed in 38 patients with a mean follow-up time of 15 months (range, 1-48 months). Eleven patients had a mentosternal burn scar contracture (12 flaps), 12 patients (13 flaps) presented with cancer, and 15 patients (18 flaps) were suffering from chronic wounds due to failed previous reconstruction (n = 6), osteoradionecrosis (n = 1), chronic infection (n = 3), bronchopleural fistula (n = 3), and pressure sores (n = 2). The mean defect size was 152 cm(2). Sixteen flaps were based on the superficial cervical artery (SCA; type 2), 16 were based on the dorsal scapular artery (DSA; type 3), one was based on the intercostal arteries (type 4), and 10 flaps were based on both the DSA and SCA. Recipient-site complications requiring reoperation occurred in 16.3%, including one total flap failure (2.6%). The trapezius myocutaneous flap is a valuable option to reconstruct various head and neck and upper back defects. Based on our data, a surgical treatment algorithm was developed in an attempt to reduce variation in care and improve clinical outcomes. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Variable camber rotor study

NASA Technical Reports Server (NTRS)

Dadone, L.; Cowan, J.; Mchugh, F. J.

1982-01-01

Deployment of variable camber concepts on helicopter rotors was analytically assessed. It was determined that variable camber extended the operating range of helicopters provided that the correct compromise can be obtained between performance/loads gains and mechanical complexity. A number of variable camber concepts were reviewed on a two dimensional basis to determine the usefulness of leading edge, trailing edge and overall camber variation schemes. The most powerful method to vary camber was through the trailing edge flaps undergoing relatively small motions (-5 deg to +15 deg). The aerodynamic characteristics of the NASA/Ames A-1 airfoil with 35% and 50% plain trailing edge flaps were determined by means of current subcritical and transonic airfoil design methods and used by rotor performance and loads analysis codes. The most promising variable camber schedule reviewed was a configuration with a 35% plain flap deployment in an on/off mode near the tip of a blade. Preliminary results show approximately 11% reduction in power is possible at 192 knots and a rotor thrust coefficient of 0.09. The potential demonstrated indicates a significant potential for expanding the operating envelope of the helicopter. Further investigation into improving the power saving and defining the improvement in the operational envelope of the helicopter is recommended.

Osteoradionecrosis of the chest wall. Management of postresection defects using Marlex mesh and a rotated latissimus dorsi myocutaneous flap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hines, G.L.; Lee, G.

1983-11-01

Full thickness chest wall resection and single stage reconstruction for osteoradionecrosis of the chest wall was performed on five patients. All patients had undergone radical mastectomy and radiation therapy from 5 to 18 years prior to chest wall resection. Defects varied from 12 X 5 cm to 15 X 15 cm, and included from two to four ribs. Reconstruction was performed using Marlex mesh to reconstruct the bony thorax and a rotated latissimus dorsi myocutaneous flap. Coverage was successfully performed in all cases, and no patient experienced postoperative pulmonary dysfunction. There were no complications related to either the bony thoraxmore » reconstruction or the latissimus flap. The use of this technique has provided a safe, convenient, and reliable method of chest wall reconstruction.« less

Free anterolateral thigh flap for reconstruction of major craniofacial defects.

PubMed

Amin, Ayman; Rifaat, Mohammed; Civantos, Francisco; Weed, Donald; Abu-Sedira, Mohammed; Bassiouny, Mahmoud

2006-02-01

Free-tissue transfer has revolutionized skull-base surgery by expanding the ability to perform cranial base resection and by improving the quality of reconstruction. The anterolateral thigh flap has come recently into use in the field of head and neck reconstruction. Its role in craniofacial and midface reconstruction has not been specifically defined. This study involved a total of 18 patients who were treated over a 5-year period from 1998 to 2003. Seventeen patients had locally advanced head and neck cancer, requiring craniofacial resection, and one patient had a complicated gun shot wound of the forehead. Thirteen patients were treated at the National Cancer Institute, Cairo University, Egypt, and five patients at the University of Miami, Florida. The patients presented with defects of the anterior skull base (5), lateral skull base (3), scalp and calvarium (3), and the midface (7). The anterolateral thigh flap was used as a myocutaneous flap in 11 cases and as a perforator fasciocutaneous flap in seven cases. Musculocutaneous perforators supplied the majority of flaps (17/18). Total flap survival occurred in 17 cases; one patient developed complete flap necrosis. The most commonly used recipient vessels were the facial vessels and the external jugular vein. Major complications included one case with meningitis; the patient died after failure of treatment. Another patient died 6 weeks postoperatively from pulmonary embolism. One patient developed CSF leak that stopped spontaneously. In addition, two patients developed minor wound dehiscence that healed spontaneously. The donor-site wound healed without problems except in two cases. One patient had an incomplete take of the skin graft; the other developed wound infection and superficial sloughing. Both wounds healed spontaneously. In addition to the feasibility of simultaneous flap harvesting with tumor resection, the flap's advantage in skull base reconstruction is its reliable blood supply, which can provide adequate dural cover and protection of the brain. Its size and moderate thickness are suitable for reconstruction of scalp and calvarial defects. The abundance of reliably vascularized fat in the flap may be an advantage in long-term maintenance of the volume of the flap in midface reconstruction. Similar to other soft tissue flaps, additional skeletal reconstruction may still be required to achieve an optimal functional and aesthetic result.

Contrast-enhanced magnetic resonance angiography for preoperative imaging of deep inferior epigastric artery perforator flaps: advantages and disadvantages compared with computed tomography angiography: a United Kingdom perspective.

PubMed

Schaverien, Mark V; Ludman, Catherine N; Neil-Dwyer, Jason; McCulley, Stephen J

2011-12-01

The anatomy of the anterior abdominal wall is highly variable and leads to uncertainty when harvesting a deep inferior epigastric artery perforator flap. Presurgical imaging has been shown to reduce the operating time, as well as reduce the rates of flap and donor site complications. The importance of imaging of the venous system has also been recognized for reducing the risk of venous congestion. The modalities currently available for presurgical imaging include handheld Doppler ultrasound, duplex ultrasound, computed tomographic angiography (CTA), and contrast-enhanced magnetic resonance angiography (CE-MRA). Of these, the most promising are CTA and CE-MRA, and advantages and disadvantages exist for both modalities. In this article, we review the use of CE-MRA for preoperative flap imaging and report our experience with its use in deep inferior epigastric artery perforator flap harvest, as well as compare it with CTA. We also explore the future directions for presurgical flap imaging.

Reconstruction of deformities resulting from penile enlargement surgery.

PubMed

Alter, G J

1997-12-01

More than 30 patients presented for reconstruction of penile deformities secondary to penile enlargement surgery performed by other physicians. Lengthening was performed by releasing the suspensory ligament of the penis and advancing pubic skin with a V-Y advancement flap. Girth was increased by injecting autologous fat. Specific complaints relating to the lengthening procedure involve hypertrophic and/or wide scars, a proximal penile hump from a thick, hair-bearing V-Y flap, and a low hanging penis. Complications relating to autologous fat injections include disappearance of fat, penile lumps and nodules, and shaft deformities. The repair of these deformities is described. From 1994 through October 1996, 19 men underwent 24 various combinations of reconstructive operations, such as scar revisions, V-Y advancement flap reversal, and removal of fat nodules and asymmetrical fat deposits. Penile appearance and function were improved. Complications include 1 hematoma requiring drainage, minor wound complications and 1 inadequately reversed V-Y flap. The methods of various repairs are discussed, including reconstructive limitations, timing and staging. Significant improvement can be achieved with proper reconstruction of penile deformities.

Reduced In-Plane, Low Frequency Helicopter Noise of an Active Flap Rotor

NASA Technical Reports Server (NTRS)

Sim, Ben W.; Janakiram, Ram D.; Barbely, Natasha L.; Solis, Eduardo

2009-01-01

Results from a recent joint DARPA/Boeing/NASA/Army wind tunnel test demonstrated the ability to reduce in-plane, low frequency noise of the full-scale Boeing-SMART rotor using active flaps. Test data reported in this paper illustrated that acoustic energy in the first six blade-passing harmonics could be reduced by up to 6 decibels at a moderate airspeed, level flight condition corresponding to advance ratio of 0.30. Reduced noise levels were attributed to selective active flap schedules that modified in-plane blade airloads on the advancing side of the rotor, in a manner, which generated counteracting acoustic pulses that partially offset the negative pressure peaks associated with in-plane, steady thickness noise. These favorable reduced-noise operating states are a strong function of the active flap actuation amplitude, frequency and phase. The associated noise reductions resulted in reduced aural detection distance by up to 18%, but incurred significant vibratory load penalties due to increased hub shear forces. Small reductions in rotor lift-to-drag ratios, of no more than 3%, were also measured

[Antegrade extended peroneal artery perforator flap for knee reconstruction].

PubMed

Ruan, Hongjiang; Cai, Peihua; Fan, Cunyi; Chai, Yimin; Liu, Shenghe

2009-03-01

To investigate the operative technique and clinical results of repairing the soft tissue defects of knee with antegrade extended peroneal artery perforator flap. From October 2007 to January 2008, 3 patients (2 men and 1 woman) with the soft tissue defects of knee were treated, with the ages of 18, 31 and 42 years, respectively. The first case sustained femur and pelvis fractures and soft tissue defect over his right popliteal fossa, which were treated with open reduction and internal fixation (ORIF) and debridement of knee joint 2 weeks ago. The second case was necrosis of skin 3 weeks after ORIF for fracture of tibial plateau. The third case suffered from open fracture of tibial plateau and soft tissue defect, which were treated with external fixation and debridement 3 weeks ago. The defect sizes were 16 cm x 9 cm, 11 cm x 6 cm and 14 cm x 7 cm. The flap was raised by dividing the peroneal artery and veins distally and elevating them proximally, which covered for the defects of knee. The flaps were designed with the size of 18 cm x 10 cm, 12 cm 7 cm and 15 cm x 8 cm. The pure vascular pedicle of the flap was 10 cm to 17 cm in length, including the peroneal vessels and one or two perforator branches. The donor site is covered by a split thickness skin graft. All flaps survived after surgery. The donor sites healed by first intention and the skin grafts survived. After following up for 6, 8 and 11 months, the appearance and function of the flaps were all satisfactory. Based on the modified HSS knee performance system, post-operative knee functional outcomes of three patients were excellent. The antegrade extended peroneal artery perforator flap supplied by a pure vascular pedicle can be a good alternative for reconstruction of knee. The flap, with a long and thin pure vascular pedicle, could provide good texture and contour matching the recipient area.

Flap reconstruction for soft-tissue defects with exposed hardware following deep infection after internal fixation of ankle fractures.

PubMed

Ovaska, Mikko T; Madanat, Rami; Tukiainen, Erkki; Pulliainen, Lea; Sintonen, Harri; Mäkinen, Tatu J

2014-12-01

The aim of the present study was to determine the outcome for patients treated with flap reconstruction following deep ankle fracture infection with exposed hardware. Out of 3041 consecutive ankle fracture operations in 3030 patients from 2006 to 2011, we identified 56 patients requiring flap reconstruction following deep infection. Thirty-two of these patients could be examined at a follow-up visit. Olerud-Molander Ankle (OMA) score, 15D score, Numeric Rating Scale (NRS), and clinical examination were used to assess the outcome. A total of 58 flap reconstructions were performed in 56 patients with a mean age of 57 years (range 25–93 years) and mean follow-up time of 52 months. The most commonly used reconstruction was a distally based peroneus brevis muscle flap with a split-thickness skin graft. A microvascular free flap was required in only one patient. 22 (39%) patients required subsequent surgical interventions because of a flap-related complication. With flap reconstruction, hardware could eventually be salvaged in 53% of patients with a non-consolidated fracture. The mean OMA score was fair or poor in 53% of the patients, and only 56% had recovered their pre-injury level of function. Half of the patients had shoe wear limitations. The 15D score showed a significantly poorer health-related quality of life compared to an age-standardised sample of the general population. The mean pain NRS was 2.1 (range 0–6), and the mean satisfaction NRS was 6.6 (range 0–10). Our study showed that successful treatment of a soft-tissue defect with exposed hardware following ankle fracture infections can be achieved with local flaps. Despite eventual reconstructive success, complications are common. Patients perceive a poorer health-related quality of life, have shoe wear limitations, and only half of them achieve their pre-injury level of function.

Functional reconstruction of total lower lip defects using innervated gracilis flap in the setting of high-energy ballistic injury to the lower face: preliminary report.

PubMed

Gurunluoglu, Raffi; Glasgow, Mark; Williams, Susan A; Gurunluoglu, Aslin; Antrobus, Jarod; Eusterman, Vincent

2012-10-01

Reconstruction of total full-thickness lower lip defects combined with extensive composite mandibular defects particularly in the setting of close-range high-energy ballistic injury presents a formidable challenge for the reconstructive plastic surgeon. While the fibular flap has been widely accepted for its usefulness in the reconstruction of composite mandibular defects, to date, there is no definitive widely established method of total lower lip reconstruction. The article presents authors' approach using innervated gracilis muscle flap for total lower lip reconstruction in the setting of high-energy gunshot injuries to the face. Three patients underwent composite mandibular defect reconstruction using fibular osteocutaneous flap and functional lower lip reconstruction using innervated gracilis muscle flap. Lip lining was reconstructed using the skin paddle of the fibular flap. The external surface of the gracilis muscle was skin-grafted. Facial artery myomucosal flap provided vermilion reconstruction in two patients. All fibular (n=3) and gracilis flap transfers (n=3) were viable. An electromyographic study at 1 year postoperatively demonstrated successful re-innervation of the gracilis muscle. Starting at about 10 weeks postoperatively, patients exhibited voluntary lip movements and oral competence. In addition, all patients achieved near-normal speech, evidence of recovered protective sensitivity and satisfactory appearance. The mean follow-up was 16.1 months. Our preliminary report in three patients demonstrated that innervated gracilis muscle transfer combined with fibular flap provides a successful reconstruction of extensive composite mandibular and total lower lip defects resulting from gunshot injuries to the face. Oral continence was achieved by combination of regained tonicity and voluntary movement of the gracilis muscle following re-innervation and assistance of the cheek muscles on the gracilis muscle. The described technique was reliable and the results were promising. Copyright © 2012 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Lower extremity soft tissue reconstruction with free flap based on subscapular artery.

PubMed

Karşıdağ, Semra; Akçal, Arzu; Turgut, Gürsel; Uğurlu, Kemal; Baş, Lütfü

2011-01-01

The purpose of our study was to evaluate the results of the reconstruction of the lower extremity defects with free flaps based on the subscapular artery. Between January, 1998 and December, 2008, 51 patients (mean age 26 years; 16 female and 35 male) presenting with a lower extremity defect underwent a reconstructive surgery with flaps based on the subscapular vascular system. Thirty-seven percent of the defects were located in the crus, 19% in the sole, 16% in the heel, and 14% in the dorsum of the foot. Eighty and a half percent of the patients had traffic-accident-related and 13.5% had burn-related tissue defects. Fifty-three percent of the patients presenting with lower extremity defects underwent reconstruction with latissimus dorsi muscle flaps, 21% with free serratus muscle and/or fascia flaps, 14% with free parascapular fasciocutaneous flaps, and 12% with free combined latissimus muscle and serratus muscle and/or fascia flaps. Anastomoses of 80% of the patients were performed on their posterior tibial artery and accompanying veins and/or foot dorsal veins. End-to-end anastomosis was performed on 14 patients, while 35 patients received end-to-side anastomosis. Six patients were treated with cross free flaps, of which 4 received cross latissimus, 1 cross serratus, and 1 cross combined serratus and latissimus flaps. End-to-side anastomoses were performed on these patients on the cross-leg tibialis posterior artery. The cross-leg anastomosis was freed 4 weeks later. In the early period, venous occlusion was observed in 4 patients and arterial and venous occlusion was present in 1 patient. New anastomoses were performed in these patients. Partial necrosis was observed in 2 patients. The average follow-up period was 61 months. Pressure-related late ulcerative lesions developed in 4 patients. The lesions of these patients were repaired by debridement and primary suturing or partial thickness skin grafts. The subscapular vascular system based flaps have an optimal vascularity once they are prepared with adequate pedicles, causing minimal donor site morbidity. These flaps are a safe and effective alternative in lower extremity reconstruction. On the other hand, in the absence of appropriate recipient vessels, single or combined cross-leg free flaps may provide successful repair.

Use of Cyanoacrylate Glue Casting for Stabilization of Periocular Skin Grafts and Flaps.

PubMed

Jackson, Colette M; Nguyen, Michelle; Mancini, Ronald

To examine a novel technique for periocular skin graft and flap stabilization using cyanoacrylate glue applied to the host bed around the perimeter of the graft or flap to create an immobile cast in the immediate postoperative period to promote successful graft take and stable anatomic position. Retrospective review was performed of a single surgeon's patients who underwent periocular skin graft or flap between August 1, 2011, and February 29, 2016, in which cyanoacrylate glue was applied postoperatively for graft stabilization. Data examined included indication for procedure, location and size of graft, postoperative complications, and length of follow up postoperatively. Of 164 cases reviewed, 9 cases were identified in which cyanoacrylate glue was used as the sole means of graft or flap stabilization. Indications for surgery included repair of cicatricial ectropion (3 cases) and repair of Mohs defect status after excision of basal or squamous cell carcinoma (6 cases). All cases involved reformation of the lower eyelid. Five cases employed full-thickness skin grafts and 4 cases employed adjacent tissue rearrangement. Size of defect repaired ranged from 8 mm to 35 mm when largest diameter was measured. Complications included mild residual ectropion or mild punctal ectropion in 2 patients who was asymptomatic and did not require further surgery. No cases were complicated by hematoma, infection, or graft necrosis. Cyanoacrylate glue can be used to successfully stabilize skin grafts and flaps in the immediate postoperative period.

[Repair of cervical postradiation ulcer following radical mastectomy with lower trapezius myocutaneous flap].

PubMed

Ning, Fanggang; Qin, Fengjun; Chen, Xin; Zhang, Guoan

2015-12-01

To explore the clinical effects of ipsilateral lower trapezius myocutaneous flap for repairing cervical ulcer as a result of radiotherapy after radical mastectomy. Six patients with cervical ulcers as a result of radiotherapy after radical mastectomy were hospitalized from March 2010 to February 2015, suffering from persistent pain in different degrees. The wound area ranged from 6 cm × 4 cm to 10 cm × 6 cm before debridement, 8 cm × 5 cm to 16 cm × 10 cm after debridement. Ipsilateral lower trapezius myocutaneous flap was used to repair the wound after thorough debridement, with the area ranging from 10 cm × 7 cm to 20 cm × 13 cm. The donor sites were sutured directly or covered with medium-thickness skin graft obtained from the back. Pain was obviously relieved in all the patients 2 days after surgery. The wounds in five patients were healed, while necrosis of superficial skin approximately 1 cm in diameter appeared at the distal end of one myocutaneous flap, and it healed after dressing change. During the follow-up period of 3 to 18 months, no recurrence of ulcer was found, the texture of the myocutaneous flaps was soft with good appearance, and the donor sites healed well. On the basis of thorough debridement, it is feasible to repair the cervical ulcer as a result of radiotherapy after radical mastectomy with the ipsilateral lower trapezius myocutaneous flap.

Predictors of free flap loss in the head and neck region: A four-year retrospective study with 451 microvascular transplants at a single centre.

PubMed

Mücke, Thomas; Ritschl, Lucas M; Roth, Maximilian; Güll, Florian D; Rau, Andrea; Grill, Sonja; Kesting, Marco R; Wolff, Klaus-Dietrich; Loeffelbein, Denys J

2016-09-01

Microvascular free flaps have become an essential part of reconstructive surgery following head and neck tumour ablation. The authors' aim was to investigate the influence of cardiovascular risk factors, preoperative irradiation, previous operations and metabolically active medication on free flap loss in order to predict patients at risk and to improve their therapy. All patients who underwent reconstructive surgery with microvascular free flaps in the head and neck region between 2009 and 2013 were retrospectively analysed. Uni- and multivariate logistic regressions were performed to determine the association between possible predictor variables for free flap loss. We included 451 patients in our analysis. The overall free flap failure rate was 4.0%. Multivariate regression analysis revealed significantly increased risks of free flap failure depending on prior attempts at microvascular transplants (p < 0.001, OR = 14.21) and length of hospitalisation (p = 0.007, OR = 1.05). With consistently low rates of flap failure, microvascular reconstruction of defects in the head and neck region has proven to be highly reliable, even in patients with comorbidities. The expertise of the operating team seems to remain the main factor affecting flap success. The only discerned independent predictor was previously failed attempts at microvascular reconstruction. Copyright © 2016 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Flap reconstruction does not increase complication rates following surgical resection of extremity soft tissue sarcoma.

PubMed

Slump, Jelena; Hofer, Stefan O P; Ferguson, Peter C; Wunder, Jay S; Griffin, Anthony M; Hoekstra, Harald J; Bastiaannet, Esther; O'Neill, Anne C

2018-02-01

Flap reconstruction plays an essential role in the surgical management of extremity soft tissue sarcoma (ESTS) for many patients. But flaps increase the duration and complexity of the surgery and their contribution to overall morbidity is unclear. This study directly compares the complication rates in patients with ESTS undergoing either flap reconstruction or primary wound closure and explores contributing factors. Eight hundred and ninety-seven patients who underwent ESTS resection followed by primary closure (631) or flap reconstruction (266) were included in this study. Data on patient, tumour and treatment variables and post-operative medical and surgical complications were collected. Univariate and multivariate regression analyses were performed to identify independent predictors of complications. Post-operative complications occurred in 33% of patients. Flap patients were significantly older, had more advanced disease and were more likely to require neoadjuvant chemo- and radiotherapy. There was no significant difference in complication rates following flap reconstruction compared to primary closure on multivariate analysis (38 vs 30.9% OR 1.12, CI 0.77-1.64, p = 0.53). Pre-operative radiation and distal lower extremity tumour location were significant risk factors in patients who underwent primary wound closure but not in those who had flap reconstruction. Patients with comorbidities, increased BMI and systemic disease were at increased risk of complications following flap reconstruction. Flap reconstruction is not associated with increased post-operative complications following ESTS resection. Flaps may mitigate the effects of some risk factors in selected patients. Copyright © 2017. Published by Elsevier Ltd.

[Surgical Procedure of Buccal Mucosal Carcinoma - Reconstruction of Mouth Angle].

PubMed

Yoshino, Aya; Kanno, Takahiro; Karino, Masaaki; Iwahashi, Teruaki; Sekine, Joji

2018-03-01

Surgical resection of the buccal mucosal carcinoma often induces soft tissue defect. The treatment plan should be considered to preserve oro-facial function and morpho-esthetics. This retrospective study reports the surgical reconstruction procedures in buccal mucosal carcinoma patients. We evaluated 4 cases(2 men, 2 women, mean age: 81.8 year-old)treated in Department of Oral and Maxillofacial Surgery, Shimane University Hospital between June 2007 and January 2017. The average size of primary tumor was 4.9 cm2. And the average size of facial skin defect in the mouth angle was 3.1 cm2. The facial local skin flaps and/or other pedicled flap were used for the reconstruction of the mouth angle. Severe contraction of the scar was manifested in 2 cases. Though reconstruction using the local pedicled flaps for full thickness skin defect in the mouth angle would be feasible, special attention is considered regarding the postoperative contraction of the scar.

Design of an antagonistic shape memory alloy actuator for flap type control surfaces

NASA Astrophysics Data System (ADS)

Dönmez, Burcu; Özkan, Bülent

2011-03-01

This paper deals with the flap control of unmanned aerial vehicles (UAVs) using shape memory alloy (SMA) actuators in an antagonistic configuration. The use of SMA actuators has the advantage of significant weight and cost reduction over the conventional actuation of the UAV flaps by electric motors or hydraulic actuators. In antagonistic configuration, two SMA actuators are used: one to rotate the flap clockwise and the other to rotate the flap counterclockwise. In this content, mathematical modeling of strain and power dissipation of SMA wire is obtained through characterization tests. Afterwards, the model of the antagonistic flap mechanism is derived. Later, based on these models both flap angle and power dissipation of the SMA wire are controlled in two different loops employing proportional-integral type and neural network based control schemes. The angle commands are converted to power commands through the outer loop controller later, which are updated using the error in the flap angle induced because of the indirect control and external effects. In this study, power consumption of the wire is introduced as a new internal feedback variable. Constructed simulation models are run and performance specifications of the proposed control systems are investigated. Consequently, it is shown that proposed controllers perform well in terms of achieving small tracking errors.

Flow-Through Free Fibula Osteocutaneous Flap in Reconstruction of Tibial Bone, Soft Tissue, and Main Artery Segmental Defects.

PubMed

Li, Zonghuan; Yu, Aixi; Qi, Baiwen; Pan, Zhenyu; Ding, Junhui

2017-08-01

The aim of this report was to present the use of flow-through free fibula osteocutaneous flap for the repair of complex tibial bone, soft tissue, and main artery segmental defects. Five patients with bone, soft tissue, and segmental anterior tibial artery defects were included. The lengths of injured tibial bones ranged from 4 to 7 cm. The sizes of impaired soft tissues were between 9 × 4 and 15 × 6 cm. The lengths of defect of anterior tibial artery segments ranged from 6 to 10 cm. Two patients had distal limb perfusion problems. Flow-through free fibula osteocutaneous flap was performed for all 5 patients. Patients were followed for 12 to 18 months. All wounds healed after 1-stage operation, and all flow-through flaps survived. The distal perfusion after vascular repair was normal in all patients. Superficial necrosis of flap edge was noted in 1 case. After the local debridement and partial thickness skin graft, the flap healed uneventfully, and the surgical operation did not increase injury to the donor site. Satisfactory bone union was achieved in all patients in 2 to 4 months postoperation. Enlargement of fibula graft was observed during follow-up from 12 to 18 months. The functions of adjacent joints were recovered, and all patients were able to walk normally. Flow-through free fibula osteocutaneous flap was shown to be an effective and efficient technique for repairing composite tibial bone, soft tissue, and main artery segmental defects. This 1-stage operation should be useful in clinical practice for the treatment of complex bone, soft tissue, and vessel defects.

Posterior corneal topographic changes after partial flap during laser in situ keratomileusis

PubMed Central

Sharma, N; Rani, A; Balasubramanya, R; Vajpayee, R B; Pandey, R M

2003-01-01

Aim: To study the posterior corneal topographic changes in eyes with partial flaps during laser assisted in situ keratomileusis (LASIK). Methods: Case records of 16 patients, who had partial flap in one eye during LASIK (group 1) and uncomplicated surgery in the other eye (group 2), were studied. Following occurrence of partial flap intraoperatively, laser ablation was abandoned in all the eyes. A 160/180 μm flap was attempted during the initial procedure using the Hansatome microkeratome (Bausch & Lomb Surgicals, Munich, Germany). LASIK surgery in all cases was performed using a 180 μm plate, at the mean interval of 4.16 (SD 1.5) months following the initial procedure. None of the eyes had intraoperative complication during LASIK. Relative posterior corneal surface elevation above the best fit sphere (BFS) before the initial procedure, before, and after LASIK were compared using the Orbscan slit scanning corneal topography/pachymetry system. Results: Posterior corneal elevation was comparable in the two groups, both preoperatively (group 1; 16.4 (4.8) μm, group 2; 16.1 (4.8) μm) and after final surgery (group 1; 57.2 (15.6) μm, group 2; 54.3 (13.1) μm). In group 1 after occurrence of partial flap, the posterior corneal elevation was 16.9 (4.4) μm, and this increase was not significant statistically (p=0.4). On multiple linear regression analysis, residual bed thickness (p<0.001) was independently the significant determinant of final posterior corneal elevation in both groups. Conclusion: The inadvertent occurrence of partial flap during LASIK procedure does not contribute to the increase in posterior corneal elevation. PMID:12543743

Local full-thickness skin graft of the donor arm--a novel technique for the reduction of donor site morbidity in radial forearm free flap.

PubMed

Riecke, B; Assaf, A T; Heiland, M; Al-Dam, A; Gröbe, A; Blessmann, M; Wikner, J

2015-08-01

A novel technique to reduce donor site morbidity after radial forearm free flap (RFFF) harvest, using a local full-thickness skin graft (FTSG), is described. Thirty consecutive patients undergoing RFFF for head and neck reconstruction were enrolled in a prospective study. Donor site defect closure was performed with spindle-shaped FTSGs excised from the wavelike skin incision made for the vascular pedicle. Both the removal site of the FTSG on the volar forearm and the covered RFFF donor site healed uneventfully in 29 cases, with no impairment of function related to the skin graft. No skin graft failure and no exposure, tenting, or adherence of the flexor tendons occurred. All patients expressed satisfaction with postoperative pain, the functional outcome, and cosmetic appearance. Primary donor site defect closure could be achieved in all cases with the use of a local FTSG. This graft can be gained at the access incision for the vascular pedicle, avoids expansion of the incision for a local flap technique, and does not prolong wound healing, and thus reduces both donor site and graft site morbidity of the RFFF. This technique leads to an inconspicuous aesthetic result with no apparent relevant functional deficits and avoids the need for a second donor site. Copyright © 2015 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Reversible Humidity Sensitive Clothing for Personal Thermoregulation

PubMed Central

Zhong, Ying; Zhang, Fenghua; Wang, Meng; Gardner, Calvin J.; Kim, Gunwoo; Liu, Yanju; Leng, Jinsong; Jin, Sungho; Chen, Renkun

2017-01-01

Two kinds of humidity-induced, bendable smart clothing have been designed to reversibly adapt their thermal insulation functionality. The first design mimics the pores in human skin, in which pre-cut flaps open to produce pores in Nafion sheets when humidity increases, as might occur during human sweating thus permitting air flow and reducing both the humidity level and the apparent temperature. Like the smart human sweating pores, the flaps can close automatically after the perspiration to keep the wearer warm. The second design involves thickness adjustable clothes by inserting the bent polymer sheets between two fabrics. As the humidity increases, the sheets become thinner, thus reducing the gap between the two fabrics to reduce the thermal insulation. The insulation layer can recover its original thickness upon humidity reduction to restore its warmth-preservation function. Such humidity sensitive smart polymer materials can be utilized to adjust personal comfort, and be effective in reducing energy consumption for building heating or cooling with numerous smart design. PMID:28281646

Reversible Humidity Sensitive Clothing for Personal Thermoregulation

NASA Astrophysics Data System (ADS)

Zhong, Ying; Zhang, Fenghua; Wang, Meng; Gardner, Calvin J.; Kim, Gunwoo; Liu, Yanju; Leng, Jinsong; Jin, Sungho; Chen, Renkun

2017-03-01

Two kinds of humidity-induced, bendable smart clothing have been designed to reversibly adapt their thermal insulation functionality. The first design mimics the pores in human skin, in which pre-cut flaps open to produce pores in Nafion sheets when humidity increases, as might occur during human sweating thus permitting air flow and reducing both the humidity level and the apparent temperature. Like the smart human sweating pores, the flaps can close automatically after the perspiration to keep the wearer warm. The second design involves thickness adjustable clothes by inserting the bent polymer sheets between two fabrics. As the humidity increases, the sheets become thinner, thus reducing the gap between the two fabrics to reduce the thermal insulation. The insulation layer can recover its original thickness upon humidity reduction to restore its warmth-preservation function. Such humidity sensitive smart polymer materials can be utilized to adjust personal comfort, and be effective in reducing energy consumption for building heating or cooling with numerous smart design.

Reversible Humidity Sensitive Clothing for Personal Thermoregulation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhong, Ying; Zhang, Fenghua; Wang, Meng

Two kinds of humidity-induced, bendable smart clothing have been designed to reversibly adapt their thermal insulation functionality. The first design mimics the pores in human skin, in which pre-cut flaps open to produce pores in Nafion sheets when humidity increases, as might occur during human sweating thus permitting air flow and reducing both the humidity level and the apparent temperature. Like the smart human sweating pores, the flaps can close automatically after the perspiration to keep the wearer warm. The second design involves thickness adjustable clothes by inserting the bent polymer sheets between two fabrics. As the humidity increases, themore » sheets become thinner, thus reducing the gap between the two fabrics to reduce the thermal insulation. The insulation layer can recover its original thickness upon humidity reduction to restore its warmth-preservation function. Such humidity sensitive smart polymer materials can be utilized to adjust personal comfort, and be effective in reducing energy consumption for building heating or cooling with numerous smart design.« less

Reversible Humidity Sensitive Clothing for Personal Thermoregulation

DOE PAGES

Zhong, Ying; Zhang, Fenghua; Wang, Meng; ...

2017-03-10

Two kinds of humidity-induced, bendable smart clothing have been designed to reversibly adapt their thermal insulation functionality. The first design mimics the pores in human skin, in which pre-cut flaps open to produce pores in Nafion sheets when humidity increases, as might occur during human sweating thus permitting air flow and reducing both the humidity level and the apparent temperature. Like the smart human sweating pores, the flaps can close automatically after the perspiration to keep the wearer warm. The second design involves thickness adjustable clothes by inserting the bent polymer sheets between two fabrics. As the humidity increases, themore » sheets become thinner, thus reducing the gap between the two fabrics to reduce the thermal insulation. The insulation layer can recover its original thickness upon humidity reduction to restore its warmth-preservation function. Such humidity sensitive smart polymer materials can be utilized to adjust personal comfort, and be effective in reducing energy consumption for building heating or cooling with numerous smart design.« less

V/STOL model fan stage rig design report

NASA Technical Reports Server (NTRS)

Cheatham, J. G.; Creason, T. L.

1983-01-01

A model single-stage fan with variable inlet guide vanes (VIGV) was designed to demonstrate efficient point operation while providing flow and pressure ratio modulation capability required for a V/STOL propulsion system. The fan stage incorporates a split-flap VIGV with an independently actuated ID flap to permit independent modulation of fan and core engine airstreams, a flow splitter integrally designed into the blade and vanes to completely segregate fan and core airstreams in order to maximize core stream supercharging for V/STOL operation, and an EGV with a variable leading edge fan flap for rig performance optimization. The stage was designed for a maximum flow size of 37.4 kg/s (82.3 lb/s) for compatibility with LeRC test facility requirements. Design values at maximum flow for blade tip velocity and stage pressure ratio are 472 m/s (1550 ft/s) and 1.68, respectively.

Risk factors for loss of epithelial flap integrity in laser-assisted subepithelial keratectomy surgery.

PubMed

Galindo, Joanna; Fadlallah, Ali; Robinson, Steve; Chelala, Elias; Melki, Samir A

2016-04-01

To evaluate risk factors leading to loss of epithelial flap integrity in laser-assisted subepithelial keratectomy (LASEK). Boston Eye Group, Brookline, Massachusetts, USA. Retrospective case study. This retrospective chart review was performed for LASEK surgeries that occurred between January 2009 and October 2013. Logistic regression was performed to determine whether epithelium preservation was correlated with age, sex, sphere, cylinder, spherical equivalent (SE), keratometry, and central corneal thickness (CCT). The study reviewed 1009 eyes of 509 patients with a mean age of 29.1 years ± 12.2 (SD). The mean preoperative spherical refraction was -4.7 ± 2.5 diopters (D), and the mean preoperative cylinder was -1.1 ± 0.8 D. The mean preoperative decimal corrected distance visual acuity was 1.01 ± 0.07. Single-sheet mobilization of the loosened epithelium flap was found in 72.3% of cases. Fragmented preservation events occurred in 17.6% of cases; the flap was discarded in 10.0% of cases. Epithelium preservation was significantly correlated with age (P = .048) but not with other parameters (P > .05 for sex, sphere, cylinder, SE, keratometry, CCT, and surgeon experience). Epithelial flap dissection was less likely to lead to a single epithelial sheet in patients older than 50 years than in younger patients (56.3% versus 74.9%). The mean postoperative decimal uncorrected distance visual acuity (UDVA) at 3 months was 0.98 ± 0.08. There was no statistical difference in postoperative UDVA between the undiscarded flap group and discarded flap group (P = .128). Successful dissection of single-sheet epithelial flap diminished with age. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Noise characteristics of upper surface blown configurations. Experimental program and results

NASA Technical Reports Server (NTRS)

Brown, W. H.; Searle, N.; Blakney, D. F.; Pennock, A. P.; Gibson, J. S.

1977-01-01

An experimental data base was developed from the model upper surface blowing (USB) propulsive lift system hardware. While the emphasis was on far field noise data, a considerable amount of relevant flow field data were also obtained. The data were derived from experiments in four different facilities resulting in: (1) small scale static flow field data; (2) small scale static noise data; (3) small scale simulated forward speed noise and load data; and (4) limited larger-scale static noise flow field and load data. All of the small scale tests used the same USB flap parts. Operational and geometrical variables covered in the test program included jet velocity, nozzle shape, nozzle area, nozzle impingement angle, nozzle vertical and horizontal location, flap length, flap deflection angle, and flap radius of curvature.

Physics-Based Design of Micro Air Vehicles

DTIC Science & Technology

2012-04-01

7   Figure 5. Comparison of an insect wing and a manufactured wing for a flapping MAV. .............. 8...topologies for a flapping-wing compliant actuation mechanism. Hatched areas are clamped. Cases 1-3 have fixed supports; cases 4 and 5 have variable...world by flying insects , birds, and mammals. However, an inadequate understanding of the complex, nonlinear, and multidisciplinary physics that

A Randomized Comparative Study of Two Techniques to Optimize the Root Coverage Using a Porcine Collagen Matrix.

PubMed

Reino, Danilo Maeda; Maia, Luciana Prado; Fernandes, Patrícia Garani; Souza, Sergio Luis Scombatti de; Taba Junior, Mario; Palioto, Daniela Bazan; Grisi, Marcio Fermandes de Moraes; Novaes, Arthur Belém

2015-10-01

The aim of this randomized controlled clinical study was to compare the extended flap technique (EFT) with the coronally advanced flap technique (CAF) using a porcine collagen matrix (PCM) for root coverage. Twenty patients with two bilateral gingival recessions, Miller class I or II on non-molar teeth were treated with CAF+PCM (control group) or EFT+PCM (test group). Clinical measurements of probing pocket depth (PPD), clinical attachment level (CAL), recession height (RH), keratinized tissue height (KTH), keratinized mucosa thickness (KMT) were determined at baseline, 3 and 6 months post-surgery. At 6 months, the mean root coverage for test group was 81.89%, and for control group it was 62.80% (p<0.01). The change of recession depth from baseline was statistically significant between test and control groups, with an mean of 2.21 mm gained at the control sites and 2.84 mm gained at the test sites (p=0.02). There were no statistically significant differences for KTH, PPD or CAL comparing the two therapies. The extended flap technique presented better root coverage than the coronally advanced flap technique when PCM was used.

Repair of cocaine-related oronasal fistula with forearm radial free flap.

PubMed

Colletti, Giacomo; Allevi, Fabiana; Valassina, Davide; Bertossi, Dario; Biglioli, Federico

2013-01-01

Cocaine snorting may cause significant local ischemic necrosis and the destruction of nasal and midfacial bones and soft tissues, leading to the development of a syndrome called cocaine-induced midline destructive lesion. A review of the English-language literature reveals only a few articles describing the treatment of hard and/or soft palatal perforation related to cocaine inhalation. Described here are 4 patients with a history of cocaine abuse showing palatal lesions. From 2010 to 2013, a total of 4 patients affected by cocaine-related midline destructive lesions were referred to our department. They all presented signs of a cocaine-induced midline destructive lesion. They showed wide midfacial destruction involving the nasal septum as well as the hard and soft palates causing an ample oronasal communication. In 3 patients, oronasal communication has been treated successfully using a personal technique based on a partially de-epithelialized forearm free flap. The fourth patient had been treated only with local debridement because, when she came to our attention, her abusive habits were still unsolved. Different surgical options have been reported such as local, regional, and free flaps for hard and soft palate reconstruction. However, because of an unpredictable vascularization of the palatal tissues and owing to the scarceness of the local soft tissues, local flaps are at high risk for partial and complete failure. The transfer of free vascularized tissue, however, seems to be the most reliable and logical solution for medium- to large-sized fistulas. Among the various free flaps, we choose the radial forearm type because of the pedicle length and the flap thickness.

Suprachoroidal drainage with collagen sheet implant- a novel technique for non-penetrating glaucoma surgery.

PubMed

Szurman, Peter; Januschowski, Kai; Boden, Karl Thomas; Seuthe, Anna-Maria

2018-02-01

Our purpose was both to introduce the new technique of suprachoroidal drainage with collagen sheet implantation as a novel technique of non-penetrating glaucoma surgery and to present first results of a prospective pilot study. A superficial rectangular sclera flap of half-scleral thickness sized 4 × 4.5 mm is dissected anteriorly until clear cornea. Then, a second scleral flap is created underneath the first one sized 3.5x4mm and is cut down full-thickness to the choroid exposing the suprachoroidal space. The flap is then bluntly prepared until the scleral spur is reached. Sharp dissection above the sclera spur exposes Schlemm's canal, which is located directly anteriorly. Schlemm's canal is unroofed, juxtacanalicular meshwork is peeled and the deep flap is cut off at its base. An absorbable collagen sheet (Ologen®, Dahlhausen, Cologne, Germany) is placed into the suprachoroidal space at the level of the ciliary body, and the superficial sclera flap is sutured tightly to prevent leakage. We prospectively analyzed 65 eyes that underwent suprachoroidal drainage with collagen sheet implantation. Mean reduction of intraocular pressure after 3 months was 35.1% (from 21.0 ± 4.3 mmHg to 13.5 ± 3.4 mmHg)(p < 0.01) and after 12 months 35.6% (from 21.0 ± 4.3 mmHg to 13.5 ± 3.0  mmHg)(p < 0.01). The number of topical IOP-reducing medication decreased significantly from 3.5 ± 0.7 to 0.6 ± 0.9 and to 0.9 ± 1.1 after 3 and 12 months, respectively (p < 0.01). No serious complications occurred. Suprachoroidal drainage with collagen sheet implantation seems to be a safe and effective surgical technique for non-penetrating glaucoma surgery that yields the opportunity of a sufficient IOP reduction for eyes unsuitable for canaloplasty.

Comparison of dissection with harmonic scalpel and conventional bipolar electrocautery in deep inferior epigastric perforator flap surgery: A consecutive cohort study.

PubMed

Lee, Yoon Jae; Kim, Hak Young; Han, Hyun Ho; Moon, Suk-Ho; Byeon, Jun Hee; Rhie, Jong Won; Ahn, Sang Tae; Oh, Deuk Young

2017-02-01

Reduced tissue damage is a theoretical advantage of using an ultrasonic harmonic scalpel. We hypothesized that the harmonic scalpel would outperform electrocautery in deep inferior epigastric perforator flap surgery, possibly resulting in a shorter operative time and reduced postoperative drainage and pain. Between January and August 2015, 24 consecutive patients were assigned to immediate deep inferior epigastric perforator flap elevation (12 for bipolar electrocautery and 12 for harmonic scalpel). The main outcome variables were total operative time, flap elevation time (starting from the fascia incision), and drainage volume. We compared the number of perforators isolated and the Moon and Taylor classification of the pedicle. Data were tested for normality using the Kolmogorov-Smirnov test before analysis. Continuous variables were compared by Wilcoxon rank-sum test. Data were analyzed using the statistical software SAS, version 9.3 (SAS Institute, Cary, NC, USA). Both groups were comparable with respect to clinical characteristics (mean age, body mass index, and flap weights). There was a statistically significant difference in the operative time between dissection with the harmonic scalpel and electrocautery (305.2 vs. 380.3 min, respectively, p = 0.002). The flap elevation time was reduced, particularly when using the harmonic scalpel where its usage seems crucial for dissecting deep inferior epigastric perforators (59.8 vs. 145.9 min, respectively, p < 0.0001). No statistical difference was observed in the drainage volume and length of hospital stay between the groups. We conclude that the harmonic scalpel may be more reliable and efficient as an alternative to electrocautery. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Forelimb muscle function in pig-nosed turtles, Carettochelys insculpta: testing neuromotor conservation between rowing and flapping in swimming turtles

PubMed Central

Rivera, Angela R. V.; Blob, Richard W.

2013-01-01

Changes in muscle activation patterns can lead to new locomotor modes; however, neuromotor conservation—the evolution of new forms of locomotion through changes in structure without concurrent changes to underlying motor patterns—has been documented across diverse styles of locomotion. Animals that swim using appendages do so via rowing (anteroposterior oscilations) or flapping (dorsoventral oscilations). Yet few studies have compared motor patterns between these swimming modes. In swimming turtles, propulsion is generated exclusively by limbs. Kinematically, turtles swim using multiple styles of rowing (freshwater species), flapping (sea turtles) and a unique hybrid style with superficial similarity to flapping by sea turtles and characterized by increased dorsoventral motions of synchronously oscillated forelimbs that have been modified into flippers (Carettochelys insculpta). We compared forelimb motor patterns in four species of turtle (two rowers, Apalone ferox and Trachemys scripta; one flapper, Caretta caretta; and Carettochelys) and found that, despite kinematic differences, motor patterns were generally similar among species with a few notable exceptions: specifically, presence of variable bursts for pectoralis and triceps in Trachemys (though timing of the non-variable pectoralis burst was similar), and the timing of deltoideus activity in Carettochelys and Caretta compared with other taxa. The similarities in motor patterns we find for several muscles provide partial support for neuromotor conservation among turtles using diverse locomotor styles, but the differences implicate deltoideus as a prime contributor to flapping limb motions. PMID:23966596

Temporomandibular Joint Ankylosis After Ramus Construction With Free Fibula Flaps in Children With Hemifacial Microsomia.

PubMed

Resnick, Cory M; Genuth, Joshua; Calabrese, Carly E; Taghinia, Amir; Labow, Brian I; Padwa, Bonnie L

2018-05-28

Patients with hemifacial microsomia (HFM) and Kaban-Pruzansky type III mandibular deformities require ramus construction with autologous tissue. The free fibula flap, an alternative to the costochondral graft, has favorable characteristics for this construction but may be associated with temporomandibular joint ankylosis. The purposes of this study were to present a series of patients with HFM who underwent free fibula flap ramus construction, to determine the incidence of ankylosis, and to identify perioperative factors associated with ankylosis. We performed a retrospective cohort study of patients with HFM who underwent ramus construction with a free fibula flap at Boston Children's Hospital from 2003 to 2015. Patients who had at least 1 year of follow-up and complete medical records were included. The predictor variables included demographic information, HFM severity, surgical history, and operative details. The primary outcome variable was the occurrence of ankylosis. Descriptive statistics were calculated, and significance was set at P < .05. We included 8 patients (75% of whom were female patients) in the study sample. Patients underwent construction at a mean age of 11.4 ± 5.9 years (range, 5 to 21 years). In 5 patients (63%), ankylosis developed during the follow-up period of 7.3 ± 4.8 years. The average time from construction to ankylosis was 4.2 ± 3.7 years. The only predictor variable statistically significantly associated with ankylosis was the use of a contralateral releasing osteotomy, which reduced the rate of ankylosis (P = .035). There was a trend toward a younger age in patients in whom ankylosis developed (8.8 ± 2.6 years) compared with those without ankylosis (15.5 ± 8.1 years, P = .392). The free fibula flap can be associated with a high rate of ankylosis when used for ramus construction in patients with HFM. Passive flap insertion and/or use of a contralateral releasing osteotomy may reduce this risk. Copyright © 2018. Published by Elsevier Inc.

Reduction of structural loads using maneuver load control on the Advanced Fighter Technology Integration (AFTI)/F-111 mission adaptive wing

NASA Technical Reports Server (NTRS)

Thornton, Stephen V.

1993-01-01

A transonic fighter-bomber aircraft, having a swept supercritical wing with smooth variable-camber flaps was fitted with a maneuver load control (MLC) system that implements a technique to reduce the inboard bending moments in the wing by shifting the spanwise load distribution inboard as load factor increases. The technique modifies the spanwise camber distribution by automatically commanding flap position as a function of flap position, true airspeed, Mach number, dynamic pressure, normal acceleration, and wing sweep position. Flight test structural loads data were obtained for loads in both the wing box and the wing root. Data from uniformly deflected flaps were compared with data from flaps in the MLC configuration where the outboard segment of three flap segments was deflected downward less than the two inboard segments. The changes in the shear loads in the forward wing spar and at the roots of the stabilators also are presented. The camber control system automatically reconfigures the flaps through varied flight conditions. Configurations having both moderate and full trailing-edge flap deflection were tested. Flight test data were collected at Mach numbers of 0.6, 0.7, 0.8, and 0.9 and dynamic pressures of 300, 450, 600, and 800 lb/sq ft. The Reynolds numbers for these flight conditions ranged from 26 x 10(exp 6) to 54 x 10(exp 6) at the mean aerodynamic chord. Load factor increases of up to 1.0 g achieved with no increase in wing root bending moment with the MLC flap configuration.

Mechanical sensibility in free and island flaps of the foot.

PubMed

Rautio, J; Kekoni, J; Hämäläinen, H; Härmä, M; Asko-Seljavaara, S

1989-04-01

Mechanical sensibility in 20 free skin flaps and four dorsalis pedis island flaps, used for the reconstruction of foot defects, was analyzed with conventional clinical methods and by determining sensibility thresholds to vibration frequencies of 20, 80, and 240 Hz. To eliminate inter-individual variability, a score was calculated for each frequency by dividing the thresholds determined for each flap with values obtained from the corresponding area on the uninjured foot. The soft tissue stability of the reconstruction was assessed. Patients were divided into three groups according to the scores. In the group of flaps with the best sensibility, the threshold increases were low at all frequencies. In the group with intermediate sensibility, the relative threshold increases were greater, the higher the frequency. In the group with the poorest sensibility, no thresholds were obtained with 240 Hz frequency and the thresholds increases were very high at all frequencies. Sensibility was not related to the length of follow-up time, nor to the type or size of the flap. However, flap sensibility was closely associated with that of the recipient area, where sensibility was usually inferior to that of normal skin. The island flaps generally had better sensibility than the free flaps. There was a good correspondence between the levels of sensibility determined by clinical and quantitative methods. The quantitative data on the level of sensibility obtained with the psychophysical method were found to be reliable and free from observer bias, and are therefore recommended for future studies. The degree of sensibility may have contributed to, but was not essential for, good soft-tissue stability of the reconstruction.

The Pedicled Latissimus Dorsi Flap Provides Effective Coverage for Large and Complex Soft Tissue Injuries Around the Elbow.

PubMed

Hacquebord, Jacques H; Hanel, Douglas P; Friedrich, Jeffrey B

2017-08-01

The pedicled latissimus flap has been shown to provide effective coverage of wounds around the elbow with an average size of 100 to 147 cm 2 but with complication rates of 20% to 57%. We believe the pedicled latissimus dorsi flap is an effective and safe technique that provides reliable and durable coverage of considerably larger soft tissue defects around the elbow and proximal forearm. A retrospective review was performed including all patients from Harborview Medical Center between 1998 and 2012 who underwent coverage with pedicled latissimus dorsi flap for defects around the elbow. Demographic information, injury mechanism, soft tissue defect size, complications (minor vs major), and time to surgery were collected. The size of the soft tissue defect, complications, and successful soft tissue coverage were the primary outcome measures. A total of 18 patients were identified with variable mechanisms of injury. Average defect size around the elbow was 422 cm 2 . Three patients had partial necrosis of the distal most aspect of the flap, which was treated conservatively. One patient required a secondary fasciocutaneous flap, and another required conversion to a free latissimus flap secondary to venous congestion. Two were lost to follow-up after discharge from the hospital. In all, 88% (14 of 16) of the patients had documented (>3-month follow-up) successful soft tissue coverage with single-stage pedicled latissimus dorsi flap. The pedicled latissimus dorsi flap is a reliable option for large and complex soft tissue injuries around the elbow significantly larger than previous reports. However, coverage of the proximal forearm remains challenging.

Soft tissue reconstruction of the oral cavity: a review of current options.

PubMed

Rigby, Matthew H; Taylor, S Mark

2013-08-01

This article provides an overview of the principles of soft tissue reconstruction of the oral cavity, and reviews the recent clinical outcomes for described options. For small defects of the oral cavity, healing by secondary intention and primary closure are both excellent options and may provide functionally superior results. In defects where a split-thickness skin graft is appropriate, acellular dermis may provide results that are at least as good at lower cost. Free flaps, particularly the radial forearm and the anterolateral thigh, have become the mainstays of oral cavity soft tissue reconstruction for larger defects. Recent clinical series suggest that relatively novel regional flaps provide a reasonable alternative to free flap reconstructions for moderate and some large soft tissue defects. Soft tissue reconstruction of the oral cavity is a complex task with significant functional implications. There are a large number of reconstructive options available. Systematic appraisal of the defect and options allows the reconstructive surgeon to optimize functional potential by choosing the most appropriate reconstructive option.

Penile Reconstruction with Skin Grafts and Dermal Matrices: Indications and Management

PubMed Central

Triana Junco, Paloma; Dore, Mariela; Nuñez Cerezo, Vanesa; Jimenez Gomez, Javier; Miguel Ferrero, Miriam; Díaz González, Mercedes; Lopez-Pereira, Pedro; Lopez-Gutierrez, Juan Carlos

2017-01-01

Introduction  The penis eventually needs specific cutaneous coverage in the context of reconstructive procedures following trauma or congenital anomalies. Local flaps are the first choice but are not always available after multiple previous procedures. In these cases, skin graft and dermal matrices should be considered. Materials and Methods  This study was a retrospective review of the past 4 years of four patients with severe loss of penile shaft skin who underwent skin reconstruction. Dermal matrices and skin grafts were utilized. Dermal matrices were placed for a median of 4.5 weeks (3.0–6.0 weeks). The skin graft was harvested from the inner thigh region for split-thickness skin graft (STSG) and the inguinal region for full-thickness skin graft (FTSG). Results  The four patients presented with complete loss of skin in the penile shaft. One patient had a vesical exstrophy, one had a buried penis with only one corpus cavernosum, one had a wide congenital lymphedema of the genitalia, and one had a lack of skin following circumcision at home. They underwent reconstruction with three patients undergoing split-thickness skin graft; two dermal matrices; and one full-thickness graft, respectively, thereby achieving a good cosmetic and functional result. There were no complications, and all the patients successfully accepted the graft. Conclusion  Dermal matrices and skin grafts may serve as effective tools in the management of severe penile skin defects unable to be covered with local flaps. PMID:28868232

Impact of coronary artery stent edge dissections on long-term clinical outcome in patients with acute coronary syndrome: an optical coherence tomography study.

PubMed

Bouki, Konstantina P; Sakkali, Eleni; Toutouzas, Konstantinos; Vlad, Delia; Barmperis, Dimitrios; Phychari, Stavroula; Riga, Maria; Apostolou, Thomas; Stefanadis, Christodoulos

2015-08-01

The purpose of the present study was to assess the incidence, predictors and long term prognosis of stent edge dissections identified by (OCT) after the implantation of bare metal (BMS) and drug eluting stents (DES). We studied 74 patients who underwent percutaneous coronary intervention (PCI) because of an acute coronary syndrome. Edge dissections were found in 29 of 74 patients (39.1%). Independent predictors of edge dissections were: the presence of ST-elevation myocardial infarction (STEMI) (P = 0.005, odds ratio 11.78; 95% Cl 2.06-67.10), the small reference lumen diameter (P = 0.009, odds ratio 0.11; 95% Cl 0.02-0.58) and the short stents implanted (P = 0.013, odds ratio 0.83; 95% Cl 0.72-0.96). During a follow-up period of 25.6 ± 9.4 months 11 patients presented with at least one major adverse cardiac event. Event free survival was significantly decreased in patients with edge dissection with a flap thickness >0.31 mm compared to patients with thinner flap or without any dissection (P < 0.001). OCT frequently detects edge dissections, usually related to STEMI presentation and to PCI technique. Deep vessel wall injury at stent edges with a dissection flap thickness more than 0.31mm carries an adverse clinical impact on long-term clinical outcome. © 2015 Wiley Periodicals, Inc.

Results of a Two-stage Technique for Treatment of Proximal Hypospadias with Severe Curvature: Creation of a Urethral Plate Using a Vascularized Preputial Island Flap.

PubMed

Ozcan, Rahsan; Emre, Senol; Kendigelen, Pinar; Elicevik, Mehmet; Emir, Haluk; Soylet, Yunus; Buyukunal, S N Cenk

2016-04-16

To present the results of a two-stage technique used for the treatment of proximal hypospadias with severe curvature. The medical records of children with proximal hypospadias and severe curvature were retrospectively analyzed. A 2-stage procedure was performed in 30 children. In the first stage, the release of chordee was performed, and a well-vascularized preputial island flap was created. The vascularized island flap was brought anteriorly and sutured over the ventral surface of the glans and degloved penile shaft. The second stage was performed 6-8 months later. A neourethra was reconstructed by the tubularization of the preputial-urethral plate utilizing the principles of Duplay technique. All surgical procedures were performed between 2005 and 2011. The mean age of the patients was 4.4 years (1-17 years). The mean duration of urethral catheterization was 6 days after the first stage and 10 days following the second stage. The flaps were viable in all of the children. There was no residual chordee. Following the second stage (n = 30), complications developed in 11 children (36%), namely, a fistula in 7, a pinpoint fistula in 3, and a diverticulum formation in 1. The cosmetic outcome was satisfactory. Uroflowmetry measurements were evaluated, and only one patient had a diverticulum formation at the late follow-up. Vascularized preputial island flap is an alternative to free grafts for the reconstruction of the urethra. The main advantage of this flap technique is the creation of a thick, healthy and well-vascularized urethral plate. The advantages of this technique include better aesthetic appearance, an acceptable complication rate, and a very low rate of diverticula formation.

Two-Year Outcome of a Patient Treated With Phototherapeutic Keratectomy and Autologous SMILE Lenticule Transplantation for Flap-Related Complications Following LASIK.

PubMed

Zhao, Jing; Zhao, Feng; Huang, Jinrong; Xu, Haipeng; Chen, Yingjun; Zhou, Xingtao

2018-04-01

To describe a patient with flap complications after LASIK who was subsequently treated using phototherapeutic keratectomy (PTK) and an autologous lenticule transplant obtained via small incision lenticule extraction (SMILE). A 23-year-old man experienced free flap and partial flap loss in the left eye following LASIK, resulting in corneal stroma opacity 1 month later. The manifest refraction was -3.25 diopters sphere (DS)/-0.50 diopters cylinder (DC) × 100° in the right eye and +2.50 DS/-1.25 DC × 155° in the left eye. His left eye was treated with PTK and transplantation of an autologous lenticule obtained from his right eye using the SMILE procedure. At the 2-year follow-up visit, the uncorrected distance visual acuity of the left eye had improved from 20/100 to 20/22 and the corrected distance visual acuity had improved from 20/25 to 20/18. Central corneal thickness had increased from 464 to 499 µm. The mean keratometry value had decreased from 45.00 diopters (D) at the 1-month follow-up visit to 39.40 D at the 2-year follow-up visit. Optical coherence tomography examination revealed that the lenticule remained transparent and exhibited a visible demarcation line. The transplantation of an autologous lenticule obtained via SMILE combined with PTK improved uncorrected and corrected acuity in this patient with flap loss after LASIK. [J Refract Surg. 2018;34(4):281-285.]. Copyright 2018, SLACK Incorporated.

Jet Flap Stator Blade Test in the High Reaction Turbine Blade Cascade Tunnel

NASA Image and Video Library

1970-03-21

A researcher examines the setup of a jet flap blade in the High Reaction Turbine Blade Cascade Tunnel at the National Aeronautics and Space Administration (NASA) Lewis Research Center. Lewis researchers were seeking ways to increase turbine blade loading on aircraft engines in an effort to reduce the overall size and weight of engines. The ability of each blade to handle higher loads meant that fewer stages and fewer blades were required. This study analyzed the performance of a turbine blade using a jet flap and high loading. A jet of air was injected into the main stream from the pressure surface near the trailing edge. The jet formed an aerodynamic flap which deflected the flow and changed the circulation around the blade and thus increased the blade loading. The air jet also reduced boundary layer thickness. The jet-flap blade design was appealing because the cooling air may also be used for the jet. The performance was studied in a two-dimensional cascade including six blades. The researcher is checking the jet flat cascade with an exit survey probe. The probe measured the differential pressure that was proportional to the flow angle. The blades were tested over a range of velocity ratios and three jet flow conditions. Increased jet flow improved the turning and decreased both the weight flow and the blade loading. However, high blade loadings were obtained at all jet flow conditions.

A Descriptive, Retrospective Study of Using an Oblique Downward-design Gluteus Maximus Myocutaneous Flap for Reconstruction of Ischial Pressure Ulcers.

PubMed

Chou, Chang-Yi; Sun, Yu-Shan; Shih, Yu-Jen; Tzeng, Yuan-Sheng; Chang, Shun-Cheng; Dai, Niann-Tzyy; Lin, Chin-Ta

2018-03-01

Despite advances in reconstruction techniques, ischial pressure ulcers continue to present a challenge for the plastic surgeon. The purpose of this retrospective study was to evaluate outcomes of using an oblique downward gluteus maximus myocutaneous (GMM) flap for coverage of grade IV ischial ulcers. Data regarding defect size, flap size, operation time, duration of wound healing, and surgical outcome were abstracted from the medical records of patients whose ischial pressure ulcers had been reconstructed using GMM island flaps between January 2010 and December 2015. The 22 patients comprised 15 men and 7 women with a mean age of 52 (range 16-81) years. Twenty (20) had paraplegia, 6 had a recurrent ischial ulcer, 2 were bedridden following a cerebrovascular accident, 1 had a myelomeningocele status post operation, and 19 were spinal cord injury patients. Follow-up time ranged from 6 to 40 months. Pressure ulcer size ranged from 3 cm x 2 cm to 10 cm x 5 cm (average 22.3 cm2). The average flap size was 158 cm2 (15.9 cm x 9.7 cm); the largest was 286 cm2 (22 cm x 13 cm). The operating time ranged from 52 minutes to 110 minutes (average, 80 minutes). In 2 cases, wound dehiscence occurred but completely healed after resuturing. One (1) ischial pressure ulcer recurred 6 months following surgery and was successfully covered with a pedicled anterolateral thigh flap. No recurrences or problems were observed in the remaining 20 patients. Time to complete wound healing ranged from 14 to 24 days (average 17.8 days). Treatment of ischial pressure ulcers with GMM flaps allowed for an easy, simple procedure that provided the adequate thickness of soft tissue needed to cover the bony prominence, fill dead space, and cover the lesion. This technique was a reliable and safe reconstructive modality for the management of ischial pressure ulcers, even in recurrent cases.

Inverted u-shaped purse and rotation flaps: correcting the inferoposterior deformity of reconstructed ears after canaloplasty of the external auditory meatus.

PubMed

Ji, Chenyang; Zhang, Jinming; An, Geng; Liang, Weiqiang; Pan, Shujuan; Chen, Yuhong; Wei, Zhe; Zhang, Ganlin

2012-06-01

After patients with congenital microtia receive external ear canal plasty, the mastoid area usually has insufficient space for ear reconstruction. Hence, after ear reconstruction, an inferoposterior position deformity of the ear appears to some extent. Using inverted U-shaped purse and rotation flaps can correct this deformity effectively. From May of 2009 to September of 2011, five patients received the described procedures in the authors' department. Inverted U-shaped purse and rotation flaps were used for all the patients. The inverted U-shaped purse flap was used to reduce the area of the canal orifice and to lower the position, and the rotation flap was applied to turn the ear in a more superoposterior position. Two patients also received full-thickness skin grafting to cover the secondary wound. In four patients, V-Y-plasty or Z-plasty was used to adjust the flap transition. For the five patients, the distances between the ear antihelix and canal orifice were shortened, and the areas of the canal orifice were diminished. The retroversion of the auricle was corrected in various degrees, and the angles of the long axis of the auricle and the horizontal line were increased an average of 14.4°. The vertical distance between the top of the helix and the center of the canal orifice was increased an average of 15.2 mm. A slight dog ear deformity in front of the crus of the helix was left after the operation, but it was alleviated in the follow-up period. By using inverted U-shaped purse and rotation flaps, the inferoposterior position deformity of the reconstructed ear after external ear canal plasty in congenital microtia can be resolved effectively. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors http://www.springer.com/00266.

Coronally advanced flap with or without porcine collagen matrix for root coverage: a randomized clinical trial.

PubMed

Moreira, Ana Regina Oliveira; Santamaria, Mauro Pedrine; Silvério, Karina Gonzales; Casati, Marcio Zaffalon; Nociti Junior, Francisco Humberto; Sculean, Anton; Sallum, Enilson Antonio

2016-12-01

The objective of this study is to clinically evaluate the outcomes following treatment of single gingival recessions with either coronally advanced flap technique (CAF) alone or combined with a porcine collagen matrix graft (CM). This is a randomized parallel design clinical trial, including forty patients with single Miller Class I or II gingival recession, with a depth ≥ 2 mm and located at upper canines or premolars. The patients were randomly assigned to receive either CAF or CAF + CM. The primary outcome variable was gingival recession reduction (Rec Red). Baseline recession depth was 3.14 ± 0.51 mm for CAF group and 3.16 ± 0.65 mm for CAF + CM group (p > 0.05). Both groups showed significant Rec Red (p < 0.05), up to 6 months. Rec Red for CAF + CM was 2.41 ± 0.73 mm and was 2.25 ± 0.50 mm for CAF alone (p > 0.05). Root coverage was 77.2 % in the CAF + CM group and 72.1 % in the CAF group (p > 0.05). Complete root coverage (CRC) was found in 40 % of the cases in the CAF + CM group and in 35 % of the sites treated with CAF. Keratinized tissue thickness (KTT) was 0.26 mm higher in CAF + CM group (p < 0.05). It can be concluded that CAF + CM does not provide a superior recession reduction when compared to CAF; however, it may offer a small gain in KTT after 6 months. CAF + CM can be suggested as a valid therapeutic option to achieve root coverage and some increase in soft tissue thickness after 6 months.

Low-speed aerodynamic characteristics from wind-tunnel tests of a large-scale advanced arrow-wing supersonic-cruise transport concept

NASA Technical Reports Server (NTRS)

Smith, P. M.

1978-01-01

Tests have been conducted to extend the existing low speed aerodynamic data base of advanced supersonic-cruise arrow wing configurations. Principle configuration variables included wing leading-edge flap deflection, wing trailing-edge flap deflection, horizontal tail effectiveness, and fuselage forebody strakes. A limited investigation was also conducted to determine the low speed aerodynamic effects due to slotted training-edge flaps. Results of this investigation demonstrate that deflecting the wing leading-edge flaps downward to suppress the wing apex vortices provides improved static longitudinal stability; however, it also results in significantly reduced static directional stability. The use of a selected fuselage forebody strakes is found to be effective in increasing the level of positive static directional stability. Drooping the fuselage nose, which is required for low-speed pilot vision, significantly improves the later-directional trim characteristics.

The Submental Island Flap Is a Viable Reconstructive Option for a Variety of Head and Neck Ablative Defects.

PubMed

Barton, Blair M; Riley, Charles A; Pou, Jason D; Hasney, Christian P; Moore, Brian A

2018-01-01

The submental island flap (SIF) is a pedicled flap based upon the submental artery and vein. Its utility in reconstruction following ablative head and neck procedures has been applied to various subsites including skin, lip, buccal mucosa, retromolar trigone, parotidectomy defects, and tongue. We review our experience using the SIF for reconstruction following tumor ablation. This prospective case series with medical record review includes consecutive patients undergoing SIF reconstruction following ablative surgery for malignancy at a single tertiary care facility between November 2014 and November 2016. We examined preoperative variables, surgical procedures, and postoperative outcomes. Thirty-seven patients met inclusion criteria. Twenty-nine were male; the average age was 64.3 (±12.4) years. Seventeen cancers involved the oral cavity, 11 involved the skin, 8 were in the oropharynx, and 1 was in the paranasal sinus. The average size of the SIF was 38.8 cm 2 (±17.6 cm 2 ). Four partial flap losses occurred; none required revision surgery. The average length of stay for these patients was 7.2 (±6.1) days. The SIF is a robust flap that can be reliably used for a variety of head and neck defects following tumor ablation with an acceptable rate of donor- and flap-related complications.

Primary Palatoplasty for Unilateral Cleft Lip and Palate Using Mucosal Grafts and Flaps.

PubMed

Torikai, Katsuyuki; Kijima, Takeshi; Hirakawa, Takashi; Naganishi, Hiroki; Ishiwata, Yasuo; Fukawa, Toshihiko; Funaki, Junzo; Nagaoka, Ryosuke; Suzuki, Keiko; Sano, Tsuguo

2015-09-01

The mucosal graft and flaps method (MG method) is a palatoplasty technique that was developed for the purpose of improving maxillary growth in patients with cleft palate. In the MG method, full-thickness buccal mucosa is grafted onto the raw surface created by pushback palatoplasty. The method is unlikely to result in severe scarring and has a favorable effect on maxillary growth. In addition, it is unlikely to result in oronasal fistula and provides good speech results. Overall, postive long-term treatment results have been obtained. Although the MG method is technically difficult and requires a lengthy surgery, the technique is considered to be effective for palate closure in terms of speech and maxillary growth.

Closure of the Radial Forearm Free Flap Donor Site Using the Combined Local Triangular Full-Thickness Skin Graft.

PubMed

Moreno-Sánchez, Manuel; González-García, Raúl; Ruiz-Laza, Luis; Manzano Solo de Zaldívar, Damián; Moreno-García, Carlos; Monje, Florencio

2016-01-01

Traditional donor-site closure has been associated with serious esthetic and functional morbidity. The purpose of this study was to assess morbidity in esthetics and function and measure the postoperative complications of the radial forearm free flap (RFFF) donor site after using combined local triangular full-thickness skin grafting. This prospective study of patients who underwent reconstruction of head and neck defects using an RFFF was conducted from July 2008 through December 2014. The donor site was repaired with a combined local triangular full-thickness skin graft. Quality of the scar, color match, tendon exposure, presence of necrosis, dehiscence of the suture, and presence of dysesthesia were recorded and analyzed using SPSS 21.0 software. One hundred consecutive patients (71 male and 29 female) underwent RFFF harvesting. RFFF donor-site defects ranged from 15 to 70 cm2; partial skin graft loss occurred in 7% of patients. Five patients (5%) had small dehiscences of the forearm skin graft, and 2 cases (2%) presented tendon exposure. In all cases, these sites healed secondarily by conservative management, with no final impairment of function. Esthetic results were considered excellent in 87%, good in 11%, and suboptimal in 2% of the cases. The combined local triangular full-thickness skin graft is a reliable method for closing RFFF donor-site defects because it obviates a second surgical site, it provides excellent color match and pliability, and it can be used for covering large defects of the donor site. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Feasibility and Advantages of Full Thickness Skin Graft from the Anterolateral Thigh.

PubMed

Shin, Seung-Han; Kim, Chulkyu; Lee, Yong-Suk; Kang, Jin-Woo; Chung, Yang-Guk

2017-12-01

Full thickness skin graft (FTSG) gives better outcomes than split thickness skin graft (STSG), but it has the drawback of limited donor sites. Anterolateral thigh (ALT), a popular donor site of STSG, is also a popular donor site of perforator flaps. This area has the advantage of large flap size available with primary closure. Based on this we harvested FTSG instead of STSG from the ALT. We retrospectively reviewed 10 cases of FTSG from the ALT, with the recipient site of foot in 3, ankle in 2, lower leg in 2, forearm in 2, and wrist in 1 patient. In all cases elliptical full thickness skin was harvested from the ALT, and the donor site was closed primarily. The skin was defatted and placed onto the defect with vacuum-assisted closure (VAC). The skin size ranged 7-30 cm in length and 3-12 cm in width. Mean follow up period was 7 months (range, 3-13). FTSG from the ALT provided durable wound coverage, with excellent color and texture matching. Partial (< 20%) graft failure was observed in 1 case, but no additional surgery was necessary. No patient reported donor site pain at postoperative 2 weeks. No donor site complications were encountered. No patient complained a feeling of tension in the thigh at final follow-up. FTSG from the ALT is feasible with the aid of VAC. Considering the skin quality, large skin size available, early pain relief, and little donor site morbidity, the ALT should be revisited as a donor site of FTSG.

[Effects of anteriolateral thigh perforator flap and fascia lata transplantation in combination with computed tomography angiography on repair of electrical burn wounds of head with skull exposure and necrosis].

PubMed

Li, X Q; Wang, X; Han, Y L; Ji, G; Chen, Z H; Zhang, J; Zhu, J P; Duan, J X; He, Y J; Yang, X M; Liu, W J

2018-05-20

Objective: To explore the effects of anteriolateral thigh perforator flap and fascia lata transplantation in combination with computed tomography angiography (CTA) on repair of electrical burn wounds of head with skull exposure and necrosis. Methods: Seven patients with head electrical burns accompanied by skull exposure and necrosis were admitted to our burn center from March 2016 to December 2017. Head CTA was performed before the operation. The diameters of the facial artery and vein or the superficial temporal artery and vein were measured, and their locations were marked on the body surface. Preoperative CTA for flap donor sites in lower extremities were also performed to track the descending branch of the lateral circumflex femoral artery with the similar diameter as the recipient vessels on the head, and their locations were marked on the body surface. Routine wound debridement and skull drilling were performed successively. The size of the wounds after debridement ranged from 12 cm×8 cm to 20 cm×12 cm, and the areas of skull exposure ranged from 8 cm×6 cm to 15 cm×10 cm. Anteriolateral thigh perforator flaps with areas from 13 cm×9 cm to 21 cm×13 cm containing 5-10 cm long vascular pedicles were designed and dissected accordingly. The fascia lata under the flap with area from 5 cm×2 cm to 10 cm×3 cm was dissected according to the length of vascular pedicle. The fascia lata was transplanted to cover the exposed skull, and the anteriolateral thigh perforator flap was transplanted afterwards. The descending branch of the lateral circumflex femoral artery and its accompanying vein of the flap were anastomosed with superficial temporal artery and vein or facial artery and vein before the suture of flap. The flap donor sites were covered by intermediate split-thickness skin graft collected from contralateral thigh or abdomen. Results: The descending branch of the lateral circumflex femoral artery and its accompanying vein were anastomosed with superficial temporal artery and vein in six patients, while those with facial artery and vein in one patient. All the flaps survived after the operation, and no vascular crisis was observed. Wound healing was satisfactory. One patient was lost to follow up. Six patients were followed up for 6 to 10 months. The patients were bald in the head operation area with acceptable appearance. No psychiatric symptom such as headache or epileptic seizure was reported. The flap donor sites were normal in appearance. The muscle strength of the lower extremities all reached grade V. The sensation and movement of the lower extremities were normal. Conclusions: Anterolateral thigh perforator flap with fascia lata transplantation can effectively repair electrical burn wounds of head with skull exposure and necrosis. The fascia lata can be used to protect the vascular pedicle of flaps, which is beneficial to the survival of the flap. Preoperative head and lower extremities CTA can provide reference for intraoperative vascular exploration in donor site and recipient area, so as to shorten operation time.

Design and Testing of a Morphing Wing for an Experimental UAV

DTIC Science & Technology

2007-11-01

line through the use of conformal flaps [6]. Variable cant angle winglets [7] and variable span wing [8] research has also been made. RTO-MP-AVT...A.Gatto and M.I. Friswell, “The Application of Variable Cant Angle Winglets for Morphing Aircraft Control”, University of Bristol, AIAA2006-3660, 2006

Preoperative computed tomography angiography for planning DIEP flap breast reconstruction reduces operative time and overall complications

PubMed Central

Rozen, Warren Matthew; Chowdhry, Muhammad; Band, Bassam; Ramakrishnan, Venkat V.; Griffiths, Matthew

2016-01-01

Background The approach and operative techniques associated with breast reconstruction have steadily been refined since its inception, with abdominal perforator-based flaps becoming the gold standard reconstructive option for women undergoing breast cancer surgery. The current study comprises a cohort of 632 patients, in whom specific operative times are recorded by a blinded observer, and aims to address the potential benefits seen with the use of computer tomography (CT) scanning preoperatively on operative outcomes, complications and surgical times. Methods A prospectively recorded, retrospective review was undertaken of patients undergoing autologous breast reconstruction with a DIEP flap at the St Andrews Centre over a 4-year period from 2010 to 2014. Computed tomography angiography (CTA) scanning of patients began in September 2012 and thus 2 time periods were compared: 2 years prior to the use of CTA scans and 2 years afterwards. For all patients, key variables were collected including patient demographics, operative times, flap harvest time, pedicle length, surgeon experience and complications. Results In group 1, comprising patients within the period prior to CTA scans, 265 patients underwent 312 flaps; whilst in group 2, the immediately following 2 years, 275 patients had 320 flaps. The use of preoperative CTA scans demonstrated a significant reduction in flap harvest time of 13 minutes (P<0.013). This significant time saving was seen in all flap modifications: unilateral, bilateral and bipedicled DIEP flaps. The greatest time saving was seen in bipedicle flaps, with a 35-minute time saving. The return to theatre rate significantly dropped from 11.2% to 6.9% following the use of CTA scans, but there was no difference in the total failure rate. Conclusions The study has demonstrated both a benefit to flap harvest time as well as overall operative times when using preoperative CTA. The use of CTA was associated with a significant reduction in complications requiring a return to theatre in the immediate postoperative period. Modern scanners and techniques can reduce the level of ionising radiation, facilitating patients being able to benefit from the advantages that this preoperative planning can convey. PMID:27047777

Abdominal wall reconstruction using a combination of free tensor fasciae lata and anterolateral thigh myocutaneous flap: a prospective study in 16 patients.

PubMed

Lv, Yang; Cao, Dongsheng; Guo, Fangfang; Qian, Yunliang; Wang, Chen; Wang, Danru

2015-08-01

Reconstruction of the abdominal wall continues to be a challenging problem for plastic surgeons. Transposition of well-vascularized flap tissue is the most effective way to repair composite abdominal wall defects. We retrospectively reviewed the treatment of such patients and assessed the reconstructive technique using combination of an inlay of bioprosthetic materials and a united thigh flap. A retrospective review of patients' records in the department was carried out. In total, 16 patients who underwent immediate abdominal wall reconstruction between 2000 and 2013 were identified. Patients' health status, defect sizes, and surgical technique were obtained from medical charts. The immediate reconstruction surgery of the abdominal wall was successful in all patients. One patient with dermatofibrosarcoma protuberans experienced recurrences at the former site. One patient died because of liver metastases at 21 months after surgery. No incisional hernia or infection in this series of patients was observed. Full-thickness, giant defects of the complicated abdominal wall can be repaired successfully with relatively minor complications using this reconstructive technique. Copyright © 2015 Elsevier Inc. All rights reserved.

Immediate placement and provisionalization of maxillary anterior single implant with guided bone regeneration, connective tissue graft, and coronally positioned flap procedures.

PubMed

Waki, Tomonori; Kan, Joseph Y K

2016-01-01

Immediate implant placement and provisionalization in the esthetic zone have been documented with success. The benefit of immediate implant placement and provisionalization is the preservation of papillary mucosa. However, in cases with osseous defects presenting on the facial bony plate, immediate implant placement procedures have resulted in facial gingival recession. Subepithelial connective tissue grafts for immediate implant placement and provisionalization procedures have been reported with a good esthetic outcome. Biotype conversion around implants with subepithelial connective tissue grafts have been advocated, and the resulting tissues appear to be more resistant to recession. The dimensions of peri-implant mucosa in a thick biotype were significantly greater than in a thin biotype. Connective tissue graft with coronally positioned flap procedures on natural teeth has also been documented with success. This article describes a technique combining immediate implant placement, provisionalization, guided bone regeneration (GBR), connective tissue graft, and a coronally positioned flap in order to achieve more stable peri-implant tissue in facial osseous defect situations.

Aerothermoelastic Analysis of a NASP-Like Vertical Fin

NASA Technical Reports Server (NTRS)

Rodgers, John P.

1992-01-01

Several aeroelastic stability analyses for a vertical fin similar to that of the National Aero-Space Plane are described. The objectives of the study were to design and obtain an experimental data base for a supersonic wind-tunnel model of the fin in order to examine the effects of thermal loading on the flutter characteristics. This paper describes the preliminary efforts to design the wind-tunnel model, including several of the geometric parameter variations that were analyzed. The dominant flutter mechanism involved a flap vibration mode and a fin bending mode. Variation of the thicknesses of flap and root flexures, used to attach the flap to the fin, and the fin to a support, significantly affected the flutter boundary. Uniform thermal loads, affecting only material properties, had little effect, as did the application of different uniform temperatures to each side of the fin. In contrast, the application of significant chord-wise thermal gradients induced stresses which reduced the flutter dynamic pressure by as much as 37 percent. For less extreme distributed loading, the low-aspect ratio fin was relatively unaffected.

The PELskin project-part V: towards the control of the flow around aerofoils at high angle of attack using a self-activated deployable flap.

PubMed

Rosti, Marco E; Kamps, Laura; Bruecker, Christoph; Omidyeganeh, Mohammad; Pinelli, Alfredo

2017-01-01

During the flight of birds, it is often possible to notice that some of the primaries and covert feathers on the upper side of the wing pop-up under critical flight conditions, such as the landing approach or when stalking their prey (see Fig. 1) . It is often conjectured that the feathers pop up plays an aerodynamic role by limiting the spread of flow separation . A combined experimental and numerical study was conducted to shed some light on the physical mechanism determining the feathers self actuation and their effective role in controlling the flow field in nominally stalled conditions. In particular, we have considered a NACA0020 aerofoil, equipped with a flexible flap at low chord Reynolds numbers. A parametric study has been conducted on the effects of the length, natural frequency, and position of the flap. A configuration with a single flap hinged on the suction side at 70 % of the chord size c (from the leading edge), with a length of [Formula: see text] matching the shedding frequency of vortices at stall condition has been found to be optimum in delivering maximum aerodynamic efficiency and lift gains. Flow evolution both during a ramp-up motion (incidence angle from [Formula: see text] to [Formula: see text] with a reduced frequency of [Formula: see text], [Formula: see text] being the free stream velocity magnitude), and at a static stalled condition ([Formula: see text]) were analysed with and without the flap. A significant increase of the mean lift after a ramp-up manoeuvre is observed in presence of the flap. Stall dynamics (i.e., lift overshoot and oscillations) are altered and the simulations reveal a periodic re-generation cycle composed of a leading edge vortex that lift the flap during his passage, and an ejection generated by the relaxing of the flap in its equilibrium position. The flap movement in turns avoid the interaction between leading and trailing edge vortices when lift up and push the trailing edge vortex downstream when relaxing back. This cyclic behaviour is clearly shown by the periodic variation of the lift about the average value, and also from the periodic motion of the flap. A comparison with the experiments shows a similar but somewhat higher non-dimensional frequency of the flap oscillation. By assuming that the cycle frequency scales inversely with the boundary layer thickness, one can explain the higher frequencies observed in the experiments which were run at a Reynolds number about one order of magnitude higher than in the simulations. In addition, in experiments the periodic re-generation cycle decays after 3-4 periods ultimately leading to the full stall of the aerofoil. In contrast, the 2D simulations show that the cycle can become self-sustained without any decay when the flap parameters are accurately tuned.

Design Study of Wafer Seals for Future Hypersonic Vehicles

NASA Technical Reports Server (NTRS)

Dunlap, Patrick H.; Finkbeiner, Joshua R.; Steinetz, Bruce M.; DeMange, Jeffrey J.

2005-01-01

Future hypersonic vehicles require high temperature, dynamic seals in advanced hypersonic engines and on the vehicle airframe to seal the perimeters of movable panels, flaps, and doors. Current seals do not meet the demanding requirements of these applications, so NASA Glenn Research Center is developing improved designs to overcome these shortfalls. An advanced ceramic wafer seal design has shown promise in meeting these needs. Results from a design of experiments study performed on this seal revealed that several installation variables played a role in determining the amount of leakage past the seals. Lower leakage rates were achieved by using a tighter groove width around the seals, a higher seal preload, a tighter wafer height tolerance, and a looser groove length. During flow testing, a seal activating pressure acting behind the wafers combined with simulated vibrations to seat the seals more effectively against the sealing surface and produce lower leakage rates. A seal geometry study revealed comparable leakage for full-scale wafers with 0.125 and 0.25 in. thicknesses. For applications in which lower part counts are desired, fewer 0.25-in.-thick wafers may be able to be used in place of 0.125-in.-thick wafers while achieving similar performance. Tests performed on wafers with a rounded edge (0.5 in. radius) in contact with the sealing surface resulted in flow rates twice as high as those for wafers with a flat edge. Half-size wafers had leakage rates approximately three times higher than those for full-size wafers.

Evaluating the speed of visual recovery following thin-flap LASIK with a femtosecond laser.

PubMed

Durrie, Daniel S; Brinton, Jason P; Avila, Michele R; Stahl, Erin D

2012-09-01

To investigate the speed of visual recovery following myopic thin-flap LASIK with a femtosecond laser. This pilot study prospectively evaluated 20 eyes from 10 patients who underwent bilateral simultaneous LASIK with the Femto LDV Crystal Line femtosecond laser (Ziemer Ophthalmic Systems AG) used to create a circular flap of 9.0-mm diameter and 110-μm thickness followed by photoablation with the Allegretto Wave Eye-Q (WaveLight AG) excimer laser. Binocular and monocular uncorrected distance visual acuity (UDVA), monocular contrast sensitivity, and a patient questionnaire were evaluated during the first hours, 1 day, and 1 month postoperatively. For monocular UDVA, 100% of eyes were 20/40 at 1 hour and 100% were 20/25 at 4 hours. For binocular UDVA, all patients achieved 20/32 by 30 minutes and 20/20 by 4 hours. Low frequency contrast sensitivity returned to preoperative baseline by 1 hour (P=.73), and showed a statistically significant improvement over baseline by 4 hours (P=.01). High frequency monocular contrast sensitivity returned to preoperative baseline by 4 hours (P=.48), and showed a statistically significant improvement by 1 month (P=.04). At 2 and 4 hours, 50% and 100% of patients, respectively, indicated that they would feel comfortable driving. Visual recovery after thin-flap femtosecond LASIK is rapid, occurring within the first few hours after surgery. Copyright 2012, SLACK Incorporated.

Comparison of Laser Doppler and Laser-Assisted Indocyanine Green Angiography Prediction of Flap Survival in a Novel Modification of the McFarlane Flap.

PubMed

Fourman, Mitchell Stephen; Gersch, Robert P; Phillips, Brett T; Nasser, Ahmed; Rivara, Andrew; Verma, Richa; Dagum, Alexander B; Rosengart, Todd K; Bui, Duc T

2015-07-01

The McFarlane rat ischemic dorsal skin flap model has been commonly used for clinical vector studies, as well as the testing of noninvasive diagnostics. However, variability of this model secondary to flap contact with the wound bed has led many to question its validity. Here we present a novel modification to the McFarlane skin flap using sterile silicone. We also use this model to test the prognostic efficacy of laser-assisted indocyanine green (ICG) angiography and laser Doppler imaging (LDI). A 3 × 9-cm dorsal skin flap with a cranially based pedicle was created, centered 1 cm distal to the scapulae. The flap was undermined, and in one of the 2 groups, a sterile silicone sheet was placed onto the wound bed. All flaps were then reapproximated with sutures 1-cm intervals. Clinical assessment and perfusion imaging was performed immediately postoperative, and at 24, 48, and 72 hours postsurgery. Postoperative day 7 clinical assessment was obtained before euthanasia. A comparative study using silicone blocked versus unblocked models (n = 6 per group) showed that, clinically, both models had equivalent flap survival [8.5 (0.913) vs 9.5 (1.01) cm]. However, a statistically significant increase in perfusion in the mid-third of unblocked models was observed on POD3 [20.28% (2.7%) vs blocked 13.45% (2.5%), P < 0.05], with a similar increase in the distal third on POD7 [18.73% (2.064%) vs 10.91% (4.19%), P < 0.05]. A prognostic study comparing LDI and ICG angiography prediction of POD7 survival at early time points (n = 10) found that LDI underpredicted flap survival at early time points [84.2% (12.03%) on POD0, 87.35% (16.11%) on POD1]. In contrast, ICG was more proficient [100.1% (10.1%) on POD0]. We present a modification of the McFarlane skin flap model that results in similar clinical results, but with a noted reduction in perfusion inconsistencies noted in unblocked models. The ICG angiography is superior to LDI in predicting POD7 flap necrosis within the first 48 hours postinjury. Future work will focus on histologic validation of our model, and vector efficacy testing.

Soap films burst like flapping flags.

PubMed

Lhuissier, Henri; Villermaux, Emmanuel

2009-07-31

When punctured, a flat soap film bursts by opening a hole driven by liquid surface tension. The hole rim does not, however, remain smooth but soon develops indentations at the tip of which ligaments form, ultimately breaking and leaving the initially connex film into a mist of disjointed drops. We report on original observations showing that these indentations result from a flaglike instability between the film and the surrounding atmosphere inducing an oscillatory motion out of its plane. Just like a flag edge flaps in the wind, the film is successively accelerated on both sides perpendicularly to its plane, inducing film thickness modulations and centrifuging liquid ligaments that finally pinch off to form the observed spray. This effect exemplifies how the dynamics of fragile objects such as thin liquid films is sensitive to their embedding medium.

Unique Use of Cross-Finger Flap for Reconstruction of an Index Fingertip Electrical Injury

DTIC Science & Technology

2014-01-01

5-0 nylon suture (Figures 3, 4). A full thickness (FT) skin graft was harvested from the left groin and was used to cover the donor long finger...following day and returned for weekly wound examinations. The tie-over bolster was removed from the FT skin graft of the left dorsal middle finger on

Discoloration of the mucosa caused by different restorative materials - a spectrophotometric in vitro study.

PubMed

Ioannidis, Alexis; Cathomen, Elena; Jung, Ronald E; Fehmer, Vincent; Hüsler, Jürg; Thoma, Daniel S

2017-09-01

To evaluate the discoloration of the mucosa caused by different ceramic and metal-based materials. On six pig maxillae, trap-door flaps were prepared bilaterally. Different ceramic and metal-based specimens were placed underneath the flap. To simulate increasing mucosal thicknesses (MC), connective tissue grafts (CTGs) were harvested. Spectrophotometric measurements were performed prior to flap elevation (T BL ) and for each material under the flap alone (1 mm MC) (T MC1 ), with a 1-mm CTG (2-mm MC) (T MC2 ) and with a 2-mm CTG (3-mm MC) (T MC3 ). Tested materials were as follows: Zr1 (zirconia), Zr2 (zirconia + pink ceramic), Zr3 (zirconia), Zr4 (fluorescent zirconia), Zr5 (zirconia), Zr6 (high translucent zirconia), Zr7 (low translucent zirconia) and Zr8 (low translucent zirconia), Gol (gold alloy), Ti1 (titanium alloy), Ti2 (anodized gold-shaded titanium alloy) and Ti3 (anodized pink-shaded titanium alloy). Color differences (ΔE) were calculated comparing the measurement of the native tissue (T BL ) and the measurements with varying mucosal thicknesses (T MC1-3 ). For ceramic materials, the median ΔE values for the different time-point comparison ranged as follows: 3.80 (Zr4) - 7.47 (Zr2) (pooled); 3.15 (Zr4) - 8.13 (Zr2) (T BL -T MC1 ); 3.39 (Zr4) - 7.24 (Zr2) (T BL -T MC2 ); 4.31 (Zr8) - 6.99 (Zr2) (T BL -T MC3 ). For metal-based materials, the median ΔE values were as follows: 4.20 (Gol) - 5.82 (Ti3) (pooled); 3.21 (Gol) - 13.56 (Ti1) (T BL -T CM1 ); 4.0 (Ti1) - 5.27 (Gol) (T BL -T CM2 ); 3.11 (Ti1) - 5.11 (Gol) (T BL -T CM2 ). The comparison of the materials and the time points showed in the nonparametric linear mixed model a significant interaction effect between material and time point (P < 0.001). The side was not a significant main effect, nor as term in an interaction with the other two effects. Reconstructive materials result in an evident discoloration of the mucosal tissue, tending to decrease with increasing mucosal thickness. The use of fluorescent zirconia (ceramic materials) or gold alloy (metal-based materials) lead to the least discoloration. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

A Technique to Reduce Incidence of Opaque Bubble Layer Formation During LASIK Flap Creation Using the VisuMax Femtosecond Laser.

PubMed

Wu, Ningling; Christenbury, Joseph G; Dishler, Jon G; Bozkurt, Tahir Kansu; Duel, Daniel; Zhang, Lijun; Hamilton, D Rex

2017-09-01

To identify risk factors for opaque bubble layer (OBL) formation and compare the incidence of OBL using a cone modification technique versus the original technique for LASIK flap creation using the VisuMax laser (Carl Zeiss Meditec, Jena, Germany). This retrospective study examined videos of flap creation using the VisuMax laser to identify OBL occurrence. Eyes were divided into three groups: eyes where OBL occurred using the original technique (OBL group), eyes where OBL did not occur using the original technique (no OBL group), and eyes in which the cone modification technique was used for LASIK flap creation (larger flap diameter) (cone modification technique group). Preoperative measurements including simulated keratometry (flat and steep) values, white-to-white distance (WTW), pachymetry, patient age and gender, amount of correction, flap parameters, energy setting, corneal hysteresis, and corneal resistance factor were analyzed to identify parameters with statistical difference between the OBL and no OBL groups. Incidence of OBL was compared between the original and cone modification techniques. OBL incidence was significantly lower with the cone modification technique (7.6%; 7 of 92 eyes) than with the original technique (28.8%; 34 of 118 eyes) (Fisher's exact test, P = .0009). Factors identified with a significant difference between eyes with and without OBL using the original technique were: corneal thickness (OBL: 561.2 μm, no OBL: 549.6 μm, P = .0132), WTW diameter (OBL: 11.6 mm, no OBL: 11.9 mm, P = .0048), corneal resistance factor (OBL: 10.4 mm Hg, no OBL: 9.6 mm Hg, P = 0.0329), and corneal astigmatism (OBL: 0.80 diopter, no OBL: 1.00 diopter, P = .0472) CONCLUSIONS: Less astigmatic, thicker, denser, and smaller corneas increased the risk of OBL using the original technique for flap creation. The cone modification technique was associated with lower risk of OBL formation, even in eyes with significant risk factors for OBL using the original technique. [J Refract Surg. 2017;33(9):584-590.]. Copyright 2017, SLACK Incorporated.

A 3-D Computational Study of a Variable Camber Continuous Trailing Edge Flap (VCCTEF) Spanwise Segment

NASA Technical Reports Server (NTRS)

Kaul, Upender K.; Nguyen, Nhan T.

2015-01-01

Results of a computational study carried out to explore the effects of various elastomer configurations joining spanwise contiguous Variable Camber Continuous Trailing Edge Flap (VCCTEF) segments are reported here. This research is carried out as a proof-of-concept study that will seek to push the flight envelope in cruise with drag optimization as the objective. The cruise conditions can be well off design such as caused by environmental conditions, maneuvering, etc. To handle these off-design conditions, flap deflection is used so when the flap is deflected in a given direction, the aircraft angle of attack changes accordingly to maintain a given lift. The angle of attack is also a design parameter along with the flap deflection. In a previous 2D study,1 the effect of camber was investigated and the results revealed some insight into the relative merit of various camber settings of the VCCTEF. The present state of the art has not advanced sufficiently to do a full 3-D viscous analysis of the whole NASA Generic Transport Model (GTM) wing with VCCTEF deployed with elastomers. Therefore, this study seeks to explore the local effects of three contiguous flap segments on lift and drag of a model devised here to determine possible trades among various flap deflections to achieve desired lift and drag results. Although this approach is an approximation, it provides new insights into the "local" effects of the relative deflections of the contiguous spanwise flap systems and various elastomer segment configurations. The present study is a natural extension of the 2-D study to assess these local 3-D effects. Design cruise condition at 36,000 feet at free stream Mach number of 0.797 and a mean aerodynamic chord (MAC) based Reynolds number of 30.734x10(exp 6) is simulated for an angle of attack (AoA) range of 0 to 6 deg. In the previous 2-D study, the calculations revealed that the parabolic arc camber (1x2x3) and circular arc camber (VCCTEF222) offered the best L/D characteristics and minimum drag in cruise. In the present 3-D study, calculations show that for the same C(sub t), the 3-D circular arc camber wing segment produces the largest drag for a given lift, larger than either of the two 2-D configurations, as was also conjectured in the previous study. This study indicates a wing stall around 4.5 deg angle of attack.

Upper-surface-blowing flow-turning performance

NASA Technical Reports Server (NTRS)

Sleeman, W. C., Jr.; Phelps, A. E., III

1976-01-01

Jet exhaust flow-turning characteristics were determined for systematic variations in upper-surface blowing exhaust nozzles and trailing-edge flap configuration variables from experimental wind-off (static) flow studies. For conditions with parallel flow exhausting from the nozzle, jet height (as indicated by nozzle exit height) and flap radius were found to be the most important parameters relating to flow turning. Nonparallel flow from the nozzle, as obtained from an internal roof angle and/or side spread angle, had a large favorable effect on flow turning. Comparisons made between static turning results and wind tunnel aerodynamic studies of identical configurations indicated that static flow-turning results can be indicative of wind-on powered lift performance for both good and poor nozzle-flap combinations but, for marginal designs, can lead to overly optimistic assessment of powered lift potential.

The shunt from the cyclooxygenase to lipoxygenase pathway in human osteoarthritic subchondral osteoblasts is linked with a variable expression of the 5-lipoxygenase-activating protein.

PubMed

Maxis, Kelitha; Delalandre, Aline; Martel-Pelletier, Johanne; Pelletier, Jean-Pierre; Duval, Nicolas; Lajeunesse, Daniel

2006-01-01

Osteoarthritis (OA) is characterized by articular cartilage degradation and hypertrophic bone changes with osteophyte formation and abnormal bone remodeling. Two groups of OA patients were identified via the production of variable and opposite levels of prostaglandin E2 (PGE2) or leukotriene B4 (LTB4) by subchondral osteoblasts, PGE2 levels discriminating between low and high subgroups. We studied whether the expression of 5-lipoxygenase (5-LO) or 5-LO-activating protein (FLAP) is responsible for the shunt from prostaglandins to leukotrienes. FLAP mRNA levels varied in low and high OA groups compared with normal, whereas mRNA levels of 5-LO were similar in all osteoblasts. Selective inhibition of cyclooxygenase-2 (COX-2) with NS-398-stimulated FLAP expression in the high OA osteoblasts subgroup, whereas it was without effect in the low OA osteoblasts subgroup. The addition of PGE2 to the low OA osteoblasts subgroup decreased FLAP expression but failed to affect it in the high OA osteoblasts subgroup. LTB4 levels in OA osteoblasts were stimulated about twofold by 1,25-dihydroxyvitamin D3 (1,25(OH)2D3) plus transforming growth factor-beta (TGF-beta), a situation corresponding to their effect on FLAP mRNA levels. Treatments with 1,25(OH)2D3 and TGF-beta also modulated PGE2 production. TGF-beta stimulated PGE2 production in both OA osteoblast groups, whereas 1,25(OH)2D3 alone had a limited effect but decreased the effect of TGF-beta in the low OA osteoblasts subgroup. This modulation of PGE2 production was mirrored by the synthesis of COX-2. IL-18 levels were only slightly increased in a subgroup of OA osteoblasts compared with normal; however, no relationship was observed overall between IL-18 and PGE2 levels in normal and OA osteoblasts. These results suggest that the shunt from the production of PGE2 to LTB4 is through regulation of the expression of FLAP, not 5-LO, in OA osteoblasts. The expression of FLAP in OA osteoblasts is also modulated differently by 1,25(OH)2D3 and TGF-beta depending on their endogenous low and high PGE2 levels.

Longitudinal comparison of outcomes after sub-Bowman keratomileusis and laser in situ keratomileusis: randomized, double-masked study.

PubMed

Wong, Rachel Chung Yin; Yu, Marco; Chan, Tommy C Y; Chong, Kelvin K L; Jhanji, Vishal

2015-05-01

To compare the outcomes of sub-Bowman keratomileusis (100-μm flap) and laser in situ keratomileusis (LASIK) (120-μm flap) using 150-kHz femtosecond laser. Randomized, double-masked, contralateral clinical trial. One hundred patients (200 eyes) with myopia or myopic astigmatism were included. Postoperative examinations were performed at week 1 and months 1, 3, 6, and 12. Main outcome measures included postoperative uncorrected (UCVA) and best-corrected distance visual acuity (BCVA); manifest refraction spherical equivalent; efficacy and safety indices; corneal thickness; and complications. The mean age of patients was 33.9 ± 7.9 years. Overall, the preoperative UCVA, BCVA, and manifest refraction spherical equivalent were 1.349 ± 0.332, -0.022 ± 0.033, and -5.81 ± 1.61 diopters, respectively. No significant difference was observed in preoperative (P ≥ .226) or intraoperative parameters (P ≥ .452) between both groups, except residual stromal thickness (P < .001). The UCVA, manifest refraction spherical equivalent, and central corneal thickness stabilized by 1 week, while the thinnest corneal thickness stabilized by 3 months postoperatively. There was no significant difference between both groups for any parameter during all follow-up visits (P ≥ .132) except the 3-month safety index, which was better in the sub-Bowman keratomileusis group (P = .007). Soft opaque bubble layer was noted intraoperatively in 12 cases (7, 100-μm group; 5, 120-μm group; P = .577). No postoperative complications were observed. Our study did not find any differences in the visual and refractive outcomes between femtosecond-assisted sub-Bowman keratomileusis and LASIK. Both surgeries resulted in quick visual recovery as early as 1 week postoperatively. Copyright © 2015 Elsevier Inc. All rights reserved.

A new nanosecond UV laser at 355 nm: early results of corneal flap cutting in a rabbit model.

PubMed

Trost, Andrea; Schrödl, Falk; Strohmaier, Clemens; Bogner, Barbara; Runge, Christian; Kaser-Eichberger, Alexandra; Krefft, Karolina; Vogel, Alfred; Linz, Norbert; Freidank, Sebastian; Hilpert, Andrea; Zimmermann, Inge; Grabner, Günther; Reitsamer, Herbert A

2013-12-03

A new 355 nm UV laser was used for corneal flap cutting in an animal model and tested for clinical and morphologic alterations. Corneal flaps were created (Chinchilla Bastards; n = 25) with an UV nanosecond laser at 355 nm (150 kHz, pulse duration 850 ps, spot-size 1 μm, spot spacing 6 × 6 μm, side cut Δz 1 μm; cutting depth 130 μm) and pulse energies of 2.2 or 2.5 μJ, respectively. Following slit-lamp examination, animals were killed at 6, 12, and 24 hours after treatment. Corneas were prepared for histology (hematoxylin and eosin [HE], TUNEL-assay) and evaluated statistically, followed by ultrastructural investigations. Laser treatment was tolerated well, flap lift was easier at 2.5 μJ compared with 2.2 μJ. Standard HE at 24 hours revealed intact epithelium in the horizontal cut, with similar increase in corneal thickness at both energies. Irrespective of energy levels, TUNEL assay revealed comparable numbers of apoptotic cells in the horizontal and vertical cut at 6, 12, and 24 hours, becoming detectable in the horizontal cut as an acellular stromal band at 24 hours. Ultrastructural analysis revealed regular morphology in the epi- and endothelium, while in the stroma, disorganized collagen lamellae were detectable representing the horizontal cut, again irrespective of energy levels applied. This new UV laser revealed no epi- nor endothelial damage at energies feasible for corneal flap cutting. Observed corneal swelling was lower compared with existing UV laser studies, albeit total energy applied here was much higher. Observed loss of stromal keratinocytes is comparable with available laser systems. Therefore, this new laser is suitable for refractive surgery, awaiting its test in a chronic environment.

Changes in biomechanical properties of the cornea and intraocular pressure after myopic laser in situ keratomileusis using a femtosecond laser for flap creation determined using ocular response analyzer and Goldmann applanation tonometry.

PubMed

Shin, Jonghoon; Kim, Tae Won; Park, Soo Jeong; Yoon, Min; Lee, Ji Woong

2015-03-01

To compare intraocular pressure (IOP) measurements before and after laser in situ keratomileusis (LASIK) using a femtosecond laser for flap creation, and to identify factors that may influence the preoperative and postoperative IOP, and the change in IOP after LASIK. Forty eyes from 20 patients who underwent treatment for myopia using a femtosecond laser for flap creation were enrolled in this study. The IOP and corneal biomechanical markers were prospectively measured preoperatively and 1 month after LASIK with Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA). Manifest refraction spherical equivalent, central corneal thickness, ablation depth, and mean corneal curvature (K reading) were also recorded. After LASIK, there was a significant reduction in the IOP measurement with respect to the corneal-compensated intraocular pressure (IOPcc) (Δ=-0.67±2.07 mm Hg), Goldmann-correlated pressure (IOPg) (Δ=-3.92±2.19 mm Hg), and GAT (Δ=-2.6±2.51). Multiple regression analysis revealed that the corneal hysteresis (CH) and corneal resistance factor (CRF) are statistically significant predictors of IOPcc, IOPg, and GAT (P<0.000). In this analysis, the preoperative manifest refraction spherical equivalent, CH, and CRF were significant predictors of ΔIOPcc (adjusted R²=0.401) and ΔIOPg (adjusted R²=0.386). The preoperative SE and central corneal thickness significantly predicted ΔGAT (adjusted R²=0.464). ORA provides a more complete measurement of IOP after LASIK with a femtosecond laser than GAT because ORA provides greater knowledge of the corneal biomechanics in terms of CH and CRF.

Design, fabrication and characterization of an arrayable all-polymer microfluidic valve employing highly magnetic rare-earth composite polymer

NASA Astrophysics Data System (ADS)

Rahbar, Mona; Shannon, Lesley; Gray, Bonnie L.

2016-05-01

We present a new magnetically actuated microfluidic valve that employs a highly magnetic composite polymer (M-CP) containing rare-earth hard-magnetic powder for its actuating element and for its valve seat. The M-CP offers much higher magnetization compared to the soft-magnetic, ferrite-based composite polymers typically used in microfluidic applications. Each valve consists of a permanently magnetized M-CP flap and valve seat mounted on a microfluidic channel system fabricated in poly(dimethylsiloxane) (PDMS). Each valve is actuated under a relatively small external magnetic field of 80 mT provided by a small permanent magnet mounted on a miniature linear actuator. The performance of the valve with different flap thicknesses is characterized. In addition, the effect of the magnetic valve seat on the valve’s performance is also characterized. It is experimentally shown that a valve with a 2.3 mm flap thickness, actuated under an 80 mT magnetic field, is capable of completely blocking liquid flow at a flow rate of 1 ml min-1 for pressures up to 9.65 kPa in microfluidic channels 200 μm wide and 200 μm deep. The valve can also be fabricated into an array for flow switching between multiple microfluidic channels under continuous flow conditions. The performance of arrays of valves for flow routing is demonstrated for flow rates up to 5 ml min-1 with larger microfluidic channels of up to 1 mm wide and 500 μm deep. The design of the valves is compatible with other commonly used polymeric microfluidic components, as well as other components that use the same novel permanently magnetic composite polymer, such as our previously reported cilia-based mixing devices.

A Nipple-Areolar Complex Reconstruction in Implant-Based Breast Reconstruction Using a Local Flap and Full-Thickness Skin Graft.

PubMed

Heo, Jae-Woo; Park, Seong Oh; Jin, Ung Sik

2018-06-13

Nipple-areolar complex reconstruction is the final step of the reconstructive procedure in breast cancer patients. Nowadays, a combination of a local flap for nipple reconstruction and skin grafting or tattooing for areola reconstruction is deemed a first choice. In this paper, we are combining the techniques of local flap and full-thickness skin graft from the upper inner thigh for simultaneous reconstruction of the nipple and areola. From January, 2016 to December, 2017, 23 female patients with an absent unilateral nipple-areolar complex due to post-oncological mastectomy and immediate implant-based breast reconstruction were subjects of the study. On an out-patient clinic basis, the percentage of the nipple projection loss was calculated at the intervals of 3 , 6 and 12 months postoperatively. At the final visit, the patient's subjective satisfaction on the reconstructed areola compared to the normal contralateral side was evaluated using a visual analogue scale. Over the course of time, the mean nipple projection loss was 20.16 ± 12.88, 31.78 ± 11.63 and 34.69 ± 12.01% at 3 , 6 and 12 months postoperatively, respectively. Patients' overall satisfaction on the grafted areola was as follows; the largest number of patients (8 patients) had a 'good' satisfaction 12-months postoperatively. Out of 21 patients, those who considered the result to be 'poor' and 'disappointing' each accounted for 1 and 3 patients. The combination of nipple-areolar complex reconstruction technique introduced in this study has proven to be a safe and efficacious alternative in patients with implant-based reconstruction requiring small- to medium-sized nipple projection, especially when the skin envelope is too tight for a local flap only. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Suprafascial versus traditional harvesting technique for free antero lateral thigh flap: A case-control study to assess the best functional and aesthetic result in extremity reconstruction.

PubMed

Maruccia, Michele; Fallico, Nefer; Cigna, Emanuele; Ciudad, Pedro; Nicoli, Fabio; Trignano, Emilio; Nacchiero, Eleonora; Giudice, Giuseppe; Ribuffo, Diego; Chen, Hung-Chi

2017-11-01

Clinical applications of ALT flap have currently extended to extremity (hand and foot) as well as oral cavity reconstruction. In these anatomical areas, the traditional harvesting technique presents a few disadvantages such as bulkiness of the recipient site and potential donor site morbidity including damage to the deep fascia and skin graft adhesions. The purpose of the present study was to compare the functional and aesthetic outcomes of upper and lower extremity reconstruction with either suprafascial or subfascial harvested anterolateral (ALT) flaps. Sixty patients who underwent hand or foot reconstruction with an ALT flap between January 2013 and January 2015 were included in the study (34 flaps elevated on a subfascial plane and 26 on a suprafascial plane). Group 1 (subfascial harvested ALT flap) was composed of 23 male and 11 female patients with an average age of 53.4 years (range, 36-72 years). Group 2 (suprafascial harvested ALT flap) was composed of 18 male and 8 female patients with an average age of 48.7 years (range, 32-69 years). Surgical indication was tumor resection for 20 patients in group 1 and 16 patients in group 2, chronic ulcer for 8 patients in group 1 and 6 patients in group 2, and trauma for 6 patients in group 1 and 4 patients in group 2. Complications were documented. Aesthetic outcomes were considered in terms of bulkiness of the recipient site, subsequent request for a debulking procedure, and donor site morbidity. Donor site scars were evaluated for cosmesis using a modified Hollander Wound Evaluation Scale (HWES). Skin grafts outcomes were assessed according to the modified Vancouver Scar Scale (VSS). Functional outcome at the recipient site was measured using the Enneking functional outcome score (ESS). Total range of motion (ROM) was recorded. All flaps were successfully elevated with at least one viable perforator with both approaches. The survival rates of suprafascial and subfascial harvested ALT flaps were 96.2 and 97% respectively (P = .85). The mean flap size was 110.4 ± 27.8 cm 2 in group 1 and 159.7 ± 44.4 cm 2 in group 2. The average flap thickness was 26.2± 5.2 mm in group 1 and 13.9 mm ± 4.1 in group 2. Complications included total flap loss (1 case in group 1 and 1 case in group 2), partial flap loss (2 cases in group 1 and 1 case in group 2), skin graft failure (3 cases in group 1), and muscle herniation at the donor site (1 case in group 1; P < .17). Secondary debulking procedures were needed for 20 flaps in the subfascial group and for one flap in the suprafascial group (P-value <.01). Donor site closure with skin grafts was necessary in 42 cases: 32 in group 1 and 10 in group 2. The suprafascial harvested ALT flap group reported a significant difference in terms of donor site morbidity. The HWES score of donor site scars was significantly lower in group 1 (mean 1.2 ± 0.54) than in group 2 (mean 2.4 ± 0.58), P < .01. Similarly, the VSS score for skin graft outcomes was lower in patients of group 1 (mean 4.5 ± 0.93) than in patients of group 2 (mean 6.7 ± 0.96), P < .01. There was also a significant lower score of postoperative ESS in patients of group 1 (mean 21.2 ± 3.4) when compared with patients of group 2 (mean 23.6 ± 2.7), P < .01. Total ROM improved on average 60° after surgery (P-value <.01). The suprafascial plane for elevating ALT flaps presented several advantages over the traditional subfascial approach in terms of functional and aesthetic outcomes, providing a thin flap allowing increased versatility to achieve better contour of flap, and minimizing the need for secondary debulking. © 2017 Wiley Periodicals, Inc.

Microsurgical Chest Wall Reconstruction After Oncologic Resections

PubMed Central

Sauerbier, Michael; Dittler, S.; Kreutzer, C.

2011-01-01

Defect reconstruction after radical oncologic resection of malignant chest wall tumors requires adequate soft tissue reconstruction with function, stability, integrity, and an aesthetically acceptable result of the chest wall. The purpose of this article is to describe possible reconstructive microsurgical pathways after full-thickness oncologic resections of the chest wall. Several reliable free flaps are described, and morbidity and mortality rates of patients are discussed. PMID:22294944

Use of Collagen Matrix for Augmentation of the Peri-implant Soft Tissue at the Time of Immediate Implant Placement.

PubMed

Zafiropoulos, Gregor-Georg; John, Gordon

2017-05-01

The aim of this study was to determine the treatment outcome of the use of a porcine monolayer collagen matrix (mCM) to augment peri-implant soft tissue in conjunction with immediate implant placement as an alternative to patient's own connective tissue. A total of 27 implants were placed immediately in 27 patients (14 males and 13 females, with a mean age of 52.2 years) with simultaneous augmentation of the soft tissue by the use of a mCM. The patients were randomly divided into two groups: Group I: An envelope flap was created and mCM was left coronally uncovered, and group II: A coronally repositioned flap was created and the mCM was covered by the mucosa. Soft-tissue thickness (STTh) was measured at the time of surgery (T0) and 6 months postoperatively (T1) using a customized stent. Cone beam computed tomographies (CBCTs) were taken from 12 representative cases at T1. A stringent plaque control regimen was enforced in all the patients during the 6-month observation period. Mean STTh change was similar in both groups (0.7 ± 0.2 and 0.7 ± 0.1 mm in groups I and II respectively). The comparison of STTh between T0 and T1 showed a statistically significant increase of soft tissue in both groups I and II as well as in the total examined population (p < 0.001). The STTh change as well as matrix thickness loss were comparable in both groups (p > 0.05). The evaluation of the CBCTs did not show any signs of resorption of the buccal bone plate. Within the limitations of this study, it could be concluded that the collagen matrix used in conjunction with immediate implant placement leads to an increased thickness of peri-implant soft tissue independent of the flap creation technique and could be an alternative to connective tissue graft. The collagen matrix used seems to be a good alternative to patient's own connective tissue and could be used for the soft tissue augmentation around dental implants.

Lift Optimization Study of a Multi-Element Three-Segment Variable Camber Airfoil

NASA Technical Reports Server (NTRS)

Kaul, Upender K.; Nguyen, Nhan T.

2016-01-01

This paper reports a detailed computational high-lift study of the Variable Camber Continuous Trailing Edge Flap (VCCTEF) system carried out to explore the best VCCTEF designs, in conjunction with a leading edge flap called the Variable Camber Krueger (VCK), for take-off and landing. For this purpose, a three-segment variable camber airfoil employed as a performance adaptive aeroelastic wing shaping control effector for a NASA Generic Transport Model (GTM) in landing and take-off configurations is considered. The objective of the study is to define optimal high-lift VCCTEF settings and VCK settings/configurations. A total of 224 combinations of VCK settings/configurations and VCCTEF settings are considered for the inboard GTM wing, where the VCCTEFs are configured as a Fowler flap that forms a slot between the VCCTEF and the main wing. For the VCK settings of deflection angles of 55deg, 60deg and 65deg, 18, 19 and 19 vck configurations, respectively, were considered for each of the 4 different VCCTEF deflection settings. Different vck configurations were defined by varying the horizontal and vertical distance of the vck from the main wing. A computational investigation using a Reynolds-Averaged Navier-Stokes (RANS) solver was carried out to complement a wind-tunnel experimental study covering three of these configurations with the goal of identifying the most optimal high-lift configurations. Four most optimal high-lift configurations, corresponding to each of the VCK deflection settings, have been identified out of all the different configurations considered in this study yielding the highest lift performance.

On the selection of the nozzle geometry and other parameters for cutting corneal flaps with waterjets.

PubMed

Cadavid, Ricardo; Jean, Benedikt; Wüstenberg, Dieter

2009-06-01

A cutting waterjet to produce corneal flaps during refractive surgery or to slice donor corneas for corneal grafting was developed. Jets generated with several different nozzles were compared to determine the most appropriate nozzle geometry for this application. In this paper, it is also discussed how other variables, such as stand-off distance and transverse velocity, can affect the characteristics of the cut. The cutting mechanisms, giving bases for an application of waterjets for cutting other types of tissues, are also discussed.

Efficiency enhancement of a self-propelled pitching profile using non-sinusoidal trajectories

NASA Astrophysics Data System (ADS)

Mekadem, M.; Chihani, E.; Oualli, H.; Hanchi, S.; Bouabdallah, A.; Gad-El-Hak, M.

2017-11-01

A symmetrical profile is subjected to non-sinusoidal pitching motion. The airfoil has a chord length c = 0.006 m and a semi-circular leading edge with a diameter of D = 0.001 m. The extrados and intrados are two straight lines that intersect at a tapered trailing edge, and the pitching pivot point is positioned at the leading edge. The pitching frequency is in the range of 1 <= f <= 190 Hz, while the tangential amplitude of the flapping trailing edge varies from 18% to 114% of the foil cord. To improve the airfoil propulsive performance, two-dimensional numerical simulations are implemented on FLUENT. The Reynolds number based upon the maximum profile thickness D varies in the range of 35 <= Re <= 210 , which matches insect's Reynolds numbers. The foil movement is executed using the dynamic mesh technique and a user defined function (UDF). The adopted mesh has 70,445 nodes with 5,1960 quadrilateral cells. The results are in good agreement with prior experiments, and, compared to sinusoidal oscillations, show that non-sinusoidal flapping trajectories lead to advancing velocity increase of 550%. Additionally, if improved propulsive efficiency is sought, non-sinusoidal flapping lead to better thrust.

Electrical burns of the abdomen.

PubMed

Srivastava, Rakesh Kumar; Kumar, Ritesh

2013-09-01

A 35-year-old male farmer came in contact with 11,000 volts high tension electric wire and sustained full thickness burn wounds over scapula, upper limb and anterior abdominal wall along with perforation of the intestine. Patient was initially managed conservatively in general surgery ward and was referred to us after 3 days with necrosis of the burned skin and muscles over the shoulder and abdomen. Patient was initially managed conservatively and then thorough debridement of the necrotic skin over the left shoulder and upper arm was done and the area was split skin grafted. Patient developed enterocutaneous fistula, which healed over a period of 8 weeks. The granulating wound over the abdomen was also skin grafted and patient was discharged after 18 days. About 4 months, after the discharge patient presented with ventral hernia. Repair of ventral hernia by synthetic mesh application and reconstruction of the abdominal wall with a free tensor fascia lata flap was done over the mesh, but the flap failed. Then after debridement two random pattern transposition skin flaps, one from the right upper and another from the left lower abdomen were transposed over the abdominal wound and donor area was skin grafted. Patient was discharged after 17 days.

Experimental Test Results of Energy Efficient Transport (EET) High-Lift Airfoil in Langley Low-Turbulence Pressure Tunnel

NASA Technical Reports Server (NTRS)

Morgan, Harry L., Jr.

2002-01-01

This report describes the results of an experimental study conducted in the Langley Low-Turbulence Pressure Tunnel to determine the effects of Reynolds number and Mach number on the two-dimensional aerodynamic performance of the Langley Energy Efficient Transport (EET) High-Lift Airfoil. The high-lift airfoil was a supercritical-type airfoil with a thickness-to- chord ratio of 0.12 and was equipped with a leading-edge slat and a double-slotted trailing-edge flap. The leading-edge slat could be deflected -30 deg, -40 deg, -50 deg, and -60 deg, and the trailing-edge flaps could be deflected to 15 deg, 30 deg, 45 deg, and 60 deg. The gaps and overlaps for the slat and flaps were fixed at each deflection resulting in 16 different configurations. All 16 configurations were tested through a Reynolds number range of 2.5 to 18 million at a Mach number of 0.20. Selected configurations were also tested through a Mach number range of 0.10 to 0.35. The plotted and tabulated force, moment, and pressure data are available on the CD-ROM supplement L-18221.

Unsteady Adjoint Approach for Design Optimization of Flapping Airfoils

NASA Technical Reports Server (NTRS)

Lee, Byung Joon; Liou, Meng-Sing

2012-01-01

This paper describes the work for optimizing the propulsive efficiency of flapping airfoils, i.e., improving the thrust under constraining aerodynamic work during the flapping flights by changing their shape and trajectory of motion with the unsteady discrete adjoint approach. For unsteady problems, it is essential to properly resolving time scales of motion under consideration and it must be compatible with the objective sought after. We include both the instantaneous and time-averaged (periodic) formulations in this study. For the design optimization with shape parameters or motion parameters, the time-averaged objective function is found to be more useful, while the instantaneous one is more suitable for flow control. The instantaneous objective function is operationally straightforward. On the other hand, the time-averaged objective function requires additional steps in the adjoint approach; the unsteady discrete adjoint equations for a periodic flow must be reformulated and the corresponding system of equations solved iteratively. We compare the design results from shape and trajectory optimizations and investigate the physical relevance of design variables to the flapping motion at on- and off-design conditions.

Vascular anatomy of the medial sural artery perforator flap: a new classification system of intra-muscular branching patterns.

PubMed

Dusseldorp, Joseph R; Pham, Quy J; Ngo, Quan; Gianoutsos, Mark; Moradi, Pouria

2014-09-01

The medial sural artery perforator (MSAP) flap is a versatile fasciocutaneous flap. The main difficulty encountered when raising the MSAP flap is in obtaining adequate pedicle length during intra-muscular dissection. The objective of this study was to determine the pattern of intra-muscular course of the MSAP flap pedicle. 14 cadaveric specimens were dissected and CT angiograms of 84 legs were examined. The intra-muscular branching pattern and depths of the medial sural artery branches were analyzed. The number of perforators, position of the dominant perforator and both intra-muscular and total pedicle length were also recorded and compared to existing anatomical data. Three types of arterial branching pattern were identified within the medial gastrocnemius, demonstrating one (31%), two (59%) or three or more (10%) main branches. A dominant perforator from the medial sural artery was present in 92% of anatomical specimens (13/14). Vertically, the location of the perforator from the popliteal crease was on average 13 cm (±2 cm). Transversely, the perforator originated 2.5 cm (±1 cm) from the posterior midline. Using CT angiography it was possible in 10 consecutive patients to identify a more superficial intra-muscular branch and determine the leg with the optimal branching pattern type for flap harvest. This study is the first to describe the variability of the intra-muscular arterial anatomy of the medial head of gastrocnemius muscle. Surgeons utilizing the MSAP flap option should be aware of the possible branching pattern types and consequently the differing perforator distribution and depths of intra-muscular branches. Routine use of pre-operative CT angiogram may help determine which leg has the most favorable branching pattern type and intra-muscular course for flap harvest. Copyright © 2014 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Change in reimbursement and costs in German oncological head and neck surgery over the last decade: ablative tongue cancer surgery and reconstruction with split-thickness skin graft vs. microvascular radial forearm flap.

PubMed

Hoefert, Sebastian; Lotter, Oliver

2018-05-01

Defects after ablative tongue cancer surgery can be reconstructed by split-thickness skin grafts or free microvascular flaps. The different surgical options may influence costs, reimbursement, and therefore possible profits. Our goal was to analyze the development of these parameters for different procedures in head and neck reconstruction in Germany over the last decade. After tumor resection and neck dissection of tongue cancer, three different scenarios were chosen to calculate costs, reimbursement, length of stay (LoS), and profits. Two options considered were reconstruction by split-thickness skin graft with (option Ia) and without (option Ib) tracheotomy. In addition, we analyzed microvascular reconstruction with radial forearm flap (option II). Furthermore, unsatisfactory results after options Ia and Ib may make secondary tongue plastic with split-thickness skin grafting necessary (option I+). The calculations were performed considering the German Diagnosis Related Group (DRG) system and compared to the specific DRG cost data of 250 German reference hospitals. The overall average length of stay (aLoS) declined from 16.7 to 12.8 days with a reduction in every option. Until 2011, all options showed similar accumulated DRG reimbursement. From 2012 onwards, earnings almost doubled for option II due to changes in the DRG allocation. As was expected, the highest costs were observed in option II. Profits (reimbursement minus costs) were also highest for option II (mean 2052 €, maximum 3630 Euros in 2015) followed by options Ia (765 €) and Ib/I+ (681 €). Average profits over time would be 17 to 19% higher if adjusted for inflation. We showed the development of the DRG allocation of two commonly used methods of reconstruction after ablative tongue cancer surgery and the associated LoS, reimbursement, costs, and profits. As expected, the highest values were found for microvascular reconstruction. Microvascular reconstruction may also be the primary choice of treatment from a medical point of view. However, prolonged operation times, intensive care, and hospital stay in connection with complex microvascular operations can easily turn profits into losses as opposed to the results of simple, reliable, and fast split-thickness skin grafting. The inflation rate influences profits in reimbursement systems where costs are based on a previous period of time. Surgeons find themselves daily in an area of conflict between economic interests and medical decision-making. Due to its multidimensional aspects, the choice of the reconstructive technique should be primarily based on the best medical care for the patient. But there should also be awareness of the economic risk of all three surgical procedures.

Reconstruction of a 10-mm-long median nerve gap in an ischemic environment using autologous conduits with different patterns of blood supply: A comparative study in the rat

PubMed Central

Iria, Inês; Alves, Sara; Farinho, Ana; Pen, Cláudia; Lourenço-Silva, Nuno; Mascarenhas-Lemos, Luís; Silva-Ferreira, José; Ferraz-Oliveira, Mário; Vassilenko, Valentina; Videira, Paula Alexandra; Goyri-O’Neill, João; Pais, Diogo

2018-01-01

The aim of this study was to evaluate in the Wistar rat the efficacy of various autologous nerve conduits with various forms of blood supply in reconstructing a 10-mm-long gap in the median nerve (MN) under conditions of local ischemia. A 10-mm-long median nerve defect was created in the right arm. A loose silicone tube was placed around the nerve gap zone, in order to simulate a local ischemic environment. Rats were divided in the following experimental groups (each with 20 rats): the nerve Graft (NG) group, in which the excised MN segment was reattached; the conventional nerve flap (CNF) and the arterialized neurovenous flap (ANVF) groups in which the gap was bridged with homonymous median nerve flaps; the prefabricated nerve flap (PNF) group in which the gap was reconstructed with a fabricated flap created by leaving an arteriovenous fistula in contact with the sciatic nerve for 5 weeks; and the two control groups, Sham and Excision groups. In the latter group, the proximal stump of the MN nerve was ligated and no repair was performed. The rats were followed for 100 days. During this time, they did physiotherapy. Functional, electroneuromyographic and histological studies were performed. The CNF and ANVF groups presented better results than the NG group in the following assessments: grasping test, nociception, motor stimulation threshold, muscle weight, and histomorphometric evaluation. Radial deviation of the operated forepaw was more common in rats that presented worse results in the other outcome variables. Overall, CNFs and ANVFs produced a faster and more complete recovery than NGs in the reconstruction of a 10-mm-long median nerve gap in an ischemic environment in the Wistar rat. Although, results obtained with CNFs were in most cases were better than ANVFs, these differences were not statistically significant for most of the outcome variables. PMID:29659600

Estimated Benefits of Variable-Geometry Wing Camber Control for Transport Aircraft

NASA Technical Reports Server (NTRS)

Bolonkin, Alexander; Gilyard, Glenn B.

1999-01-01

Analytical benefits of variable-camber capability on subsonic transport aircraft are explored. Using aerodynamic performance models, including drag as a function of deflection angle for control surfaces of interest, optimal performance benefits of variable camber are calculated. Results demonstrate that if all wing trailing-edge surfaces are available for optimization, drag can be significantly reduced at most points within the flight envelope. The optimization approach developed and illustrated for flight uses variable camber for optimization of aerodynamic efficiency (maximizing the lift-to-drag ratio). Most transport aircraft have significant latent capability in this area. Wing camber control that can affect performance optimization for transport aircraft includes symmetric use of ailerons and flaps. In this paper, drag characteristics for aileron and flap deflections are computed based on analytical and wind-tunnel data. All calculations based on predictions for the subject aircraft and the optimal surface deflection are obtained by simple interpolation for given conditions. An algorithm is also presented for computation of optimal surface deflection for given conditions. Benefits of variable camber for a transport configuration using a simple trailing-edge control surface system can approach more than 10 percent, especially for nonstandard flight conditions. In the cruise regime, the benefit is 1-3 percent.

Factors Influencing Postoperative Complications in Reconstructive Microsurgery for Head and Neck Cancer.

PubMed

Lo, Shih-Lun; Yen, Yu-Hsiu; Lee, Pi-Jung; Liu, Chih-Ho Charles; Pu, Chi-Ming

2017-04-01

The present study aimed to analyze multiple variables and to determine the factors influencing postoperative complications in reconstructive microsurgeries for head and neck cancer. This was a retrospective review of the medical records of patients with head and neck cancer who underwent free flap reconstruction after ablation surgery at the Cathay General Hospital (Taipei, Taiwan) from January 2010 to December 2014. Clinical and surgical procedure-related factors were retrieved from a database and analyzed. Major complications included flap failure and life-threatening events. Minor complications were defined as requiring only routine wound care or conservative treatments. To evaluate group differences, the χ 2 test was applied for categorical variables and the Mann-Whitney U test was used for continuous variables. In total, 158 patients (145 men [91.8%], 13 women [8.2%]) were included in this study. The mean age of the study population was 52.4 years (range, 34 to 84 yr). The mean body mass index (BMI) was 23.71 kg/m 2 . Most patients (93.7%) had a history of cigarette smoking. Some patients had diabetes (20.3%) and hypertension (31.6%). The percentage of patients who underwent radiotherapy before surgery was 19.6%. The percentage whose flap required a salvage operation was 8.9%. The success rate of the microvascular surgeries was 95.6%. The major complication rate was 6.3% and the minor complication rate was 27.8%. No surgical mortality was noted. In these patients, poor nutrition status, indicated by low BMI and low albumin level, was associated with a greater tendency to develop postoperative complications. Patients who had diabetes or who had received radiotherapy before surgery had a high risk for major complications. A large skin paddle seemed to be an influencing factor for minor complications, such as wound dehiscence and superficial loss of flaps. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Patient, tumour and treatment factors affect complication rates in soft tissue sarcoma flap reconstruction in a synergistic manner.

PubMed

Slump, J; Ferguson, P C; Wunder, J S; Griffin, A M; Hoekstra, H J; Liu, X; Hofer, S O P; O'Neill, A C

2017-06-01

Flap reconstruction plays an essential role in the management of soft tissue sarcoma, facilitating wide resection while maximizing preservation of function. The addition of reconstruction increases the complexity of the surgery and identification of patients who are at high risk for post-operative complications is an important part of the preoperative assessment. This study examines predictors of complications in these patients. 294 patients undergoing flap reconstruction following sarcoma resection were evaluated. Data on patient, tumour and treatment variables as well as post-operative complications were collected. Bivariate and multivariate regression analysis was performed to identify independent predictors of complications. Analysis of synergistic interaction between key patient and tumour risk factors was subsequently performed. A history of cerebrovascular events or cardiac disease were found to be the strongest independent predictors of post-operative complications (OR 14.84, p = 0.003 and OR 5.71, p = 0.001, respectively). Further strong independent tumour and treatment-related predictors were high grade tumours (OR 1.91, p = 0.038) and the need for additional reconstructive procedures (OR 2.78, p = 0.001). Obesity had significant synergistic interaction with tumour resection diameter (RERI 1.1, SI 1.99, p = 0.02) and high tumour grade (RERI 0.86, SI 1.5, p = 0.01). Comorbidities showed significant synergistic interaction with large tumour resections (RERI 0.91, SI 1.83, p = 0.02). Patient, tumour and treatment-related variables contribute to complications following flap reconstruction of sarcoma defects. This study highlights the importance of considering the combined effect of multiple risk factors when evaluating and counselling patients as significant synergistic interaction between variables can further increase the risk of complications. Copyright © 2017 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.

77 FR 29905 - Sea Turtle Conservation; Shrimp and Summer Flounder Trawling Requirements

Federal Register 2010, 2011, 2012, 2013, 2014

2012-05-21

... a bottom-opening, straight-bar grid with 2-inch bar spacing installed at an angle of 55 degrees. As...: Using \\1/4\\ inch (0.63 cm) thick and 1\\1/2\\ inch (3.8 cm) deep flat bar, and rectangular and oval pipe... currently-approved TED grids; increasing maximum mesh size on escape flaps from 1\\5/8\\ to 2 inches (4.1 to 5...

Kinematics of flap-bounding flight in the zebra finch over a wide range of speeds

PubMed

Tobalske; Peacock; Dial

1999-07-01

It has been proposed elsewhere that flap-bounding, an intermittent flight style consisting of flapping phases interspersed with flexed-wing bounds, should offer no savings in average mechanical power relative to continuous flapping unless a bird flies 1.2 times faster than its maximum range speed (Vmr). Why do some species use intermittent bounds at speeds slower than 1.2Vmr? The 'fixed-gear hypothesis' suggests that flap-bounding is used to vary mean power output in small birds that are otherwise constrained by muscle physiology and wing anatomy to use a fixed muscle shortening velocity and pattern of wing motion at all flight speeds; the 'body-lift hypothesis' suggests that some weight support during bounds could make flap-bounding flight aerodynamically advantageous in comparison with continuous flapping over most forward flight speeds. To test these predictions, we studied high-speed film recordings (300 Hz) of wing and body motion in zebra finches (Taenopygia guttata, mean mass 13.2 g, N=4) taken as the birds flew in a variable-speed wind tunnel (0-14 m s-1). The zebra finches used flap-bounding flight at all speeds, so their flight style was unique compared with that of birds that facultatively shift from continuous flapping or flap-gliding at slow speeds to flap-bounding at fast speeds. There was a significant effect of flight speed on all measured aspects of wing motion except percentage of the wingbeat spent in downstroke. Changes in angular velocity of the wing indicated that contractile velocity in the pectoralis muscle changed with flight speed, which is not consistent with the fixed-gear hypothesis. Although variation in stroke-plane angle relative to the body, pronation angle of the wing and wing span at mid-upstroke showed that the zebra finch changed within-wingbeat geometries according to speed, a vortex-ring gait with a feathered upstroke appeared to be the only gait used during flapping. In contrast, two small species that use continuous flapping during slow flight (0-4 m s-1) either change wingbeat gait according to flight speed or exhibit more variation in stroke-plane and pronation angles relative to the body. Differences in kinematics among species appear to be related to wing design (aspect ratio, skeletal proportions) rather than to pectoralis muscle fiber composition, indicating that the fixed-gear hypothesis should perhaps be modified to exclude muscle physiology and to emphasize constraints due to wing anatomy. Body lift was produced during bounds at speeds from 4 to 14 m s-1. Maximum body lift was 0.0206 N (15.9 % of body weight) at 10 m s-1; body lift:drag ratio declined with increasing air speed. The aerodynamic function of bounds differed with increasing speed from an emphasis on lift production (4-10 m s-1) to an emphasis on drag reduction with a slight loss in lift (12 and 14 m s-1). From a mathematical model of aerodynamic costs, it appeared that flap-bounding offered the zebra finch an aerodynamic advantage relative to continuous flapping at moderate and fast flight speeds (6-14 m s-1), with body lift augmenting any savings offered solely by flap-bounding at speeds faster than 7.1 m s-1. The percentage of time spent flapping during an intermittent flight cycle decreased with increasing speed, so the mechanical cost of transport was likely to be lowest at faster flight speeds (10-14 m s-1).

Inferior gluteal artery perforator flap: a viable alternative for ischial pressure sores.

PubMed

Kim, Young Seok; Lew, Dae Hyun; Roh, Tai Suk; Yoo, Won Min; Lee, Won Jai; Tark, Kwan Chul

2009-10-01

The ischial area is by far the most common site for pressure sores in wheelchair-bound paraplegic patients, because most of the pressure of the body is exerted on this area in the seated position. Even after a series of successful pressure sore treatments, the site is very prone to relapse from the simplest everyday tasks. Therefore, it is crucial to preserve the main pedicle during primary surgery. Several surgical procedures, such as myocutaneous flap and perforator flap, have been introduced for the treatment of pressure sores. During a 4-year time period at our institute, we found favourable clinical results using the inferior gluteal artery perforator (IGAP) procedure for ischial sore treatment. A total of 23 patients (20 males and three females) received IGAP flap surgery in our hospital from January 2003 to January 2007. Surgery was performed on the same site again in 10 (43%) patients who had originally relapsed after undergoing the conventional method of pressure sore surgery. The average age of patients was 47.4 years (range 26-71 years). Most of the patients were paraplegic (16 cases, 70%) and others were either quadriplegic (four cases, 17%) or ambulatory (three cases, 13%). Based on hospital records and clinical photographs, we attempted to assess the feasibility and practicability of the IGAP flap procedure through comparative analysis of several parameters including the size of the defective area, treatment modalities, relapses, complications, and postoperative treatments. The average follow-up duration for 23 subjects was 25.4 months (range 5-42 months). All flaps survived without major complications. Partial flap necrosis developed in one case but secondary healing was achieved and the final outcome was not impaired. Most of the cases healed well during the follow-up period. Postoperative complications such as wound dehiscence and fistula developed in some subjects, but all healed well with a secondary treatment. A total of five cases relapsed after surgery due to tissue deficit and these were treated with bursectomy and muscle transposition flap to fill the dead space. We propose that the IGAP flap should be considered a viable alternative to other methods of ischial pressure sore surgery owing to its many advantages, which include the ability to preserve peripheral muscle tissue, the variability of flap designs, relatively good durability, and the low donor site morbidity rate.

Extensive Necrosis After Radiation for Cancer: Experiences in Surgical Management

DOE Office of Scientific and Technical Information (OSTI.GOV)

BENNETT, JAMES E.

1963-06-01

Radionecrosis in skin and deeper tissues and its surgical repair are described in 16 cases. The observed epithelial changes included both atrophy and hypertrophy, but atrophy was the dominant feature. Epidermal hypertrophy, which preceded malignant change, developed more slowly and was less likely to occur in areas subjected to deep irradiation than in skin treated with multiple small doses of x-ray over a long period. The indolent ulceration that developed in skin augmented the changes in underlying tissues so that successful management of these ulcerations required adequate excision of the damaged area and replacement with fat-bearing pedicle flap tissue. Whenmore » adjacent flaps were used, permanent blood supply to the region was assured. In cases of radiotherapy for basal cell carcinoma of the scalp, skin necrosis resulted in skull exposure with subsequent osteomyelitis and/or bone necrosis. Excision included the full thickness of the skull, and pedicle flap tissue from the scalp was used for coverage. Cranioplasty was performed after good skin and soft tissue cover had been obtained. Therapeutic radiation of the neck invariably produces marked skin changes, and when ulceration occurs, the vulnerability of underlying structures demands surgical treatment. Lesions of the upper extremity can be excised and covered with direct pedicle flaps from the trunk. Therapeutic radiation of the retroperitoneal area may produce extensive visceral damage as well as injury to the anterior abdominal wall, and anterior suprapubic ulcerations are particularly difficult to deal with since mobile adjacent tissue is scarce. The avascular midline is a limiting factor in flap design. Abdominal flaps extending onto the thigh can be used, but these require multiple delaying procedures to insure adequate blood supply. Patients being managed by these procedures are described. Most patients underwent their operative procedures with few serious complications. While postoperative bleeding and infection are inherent hazards, most complications were traceable to errors in planning or in operative technique. When the primary procedure fails, it is often many weeks before the wound is again ready for coverage and the availability of adjacent tissue has been compromised by the operation. Therefore, it is necessary to mobilize generous amounts of normal tissue to replace the area of injury, for this may be considerably more extensive than external inspection suggests. In addition, retraction of the wound edges following excision can be considerable since surrounding normal tissue may be drawn toward the area of involvement by scar contracture. When transposition or distant pedicle flaps are used, the flaps must be designed initially to allow for coverage of the eventual wound. However, when adjacent flaps are used, they may be outlined at the beginning of the procedure and appropriate alterations are then made, as necessary, after excision of the area of involvement. It is concluded that operation is not advisable until there is pain or ulceration in the region of radiation injury. Preferred treatment consists of excision of all damaged tlssue with pedicle flap replacement.« less

[Clinical effect of distally-based dorsal thumb neurocutaneous vascular flap on repair of soft tissue defect in thumb].

PubMed

Huang, Yixiong; Shen, Zunli; Wang, Yongchun; Zhang, Shimin

2009-10-01

To investigate the surgical methods and clinical results of repairing soft tissue defects in the thumb with distally-based dorsal thumb neurocutaneous vascular flap. From January 2006 to October 2007, 23 patients with soft tissue defect in the thumb were treated, including 20 males and 3 females aged 19-46 years old (average 27.5 years old). The defect was caused by crush injury in 1 case, electric planer accident in 6 cases, incised injury in 8 cases, and avulsion injury in 8 cases. The defect was located on the palmar aspect of the thumb distal phalanx in 3 cases, the dorsal-radial aspect of the thumb distal phalanx in 3 cases, and ulnar or dorsal aspect in 17 cases. The defect size ranged from 3.3 cm x 1.2 cm to 4.2 cm x 1.2 cm. Among them, 18 cases were complicated with distal 1/2 nail bed defect or injury. The time between injury and hospital admission was 1-72 hours (average 22 hours). During operation, the defect was repaired with distally-based dorsal-radial neurovenocutaneous vascular flap of the thumb in 3 cases and distally-based dorsal-ulnar neurovenocutaneous vascular flap of the thumb in 20 cases. The size of those flaps was 4.0 cm x 1.6 cm-5.0 cm x 3.0 cm. The donor site underwent direct suture or split thickness skin graft repair. At 10 days after operation, 3 cases suffered from the epidermal necrosis in the distal part of the flap, 2 of them experienced the exfoliation of dark scab 14 days later and the flap survived, and the flap of the rest one survived after dressing change. The other flaps and the skin graft at the donor site all survived uneventfully. The wounds healed by first intention. All the patients were followed up for 10-16 months (average 12.6 months). The flaps were soft in texture and full in appearance. The two-point discrimination value 6 months after operation was 8-10 mm. At 12 months after operation, the growth of the residual fingernail was evident in 18 cases, including 4 cases of curved or hook fingernail. Active flexion and extension of the thumb were normal. The abduction of the first web space reached or surpassed 80 percent of the normal side in 20 cases and was below 80 percent of the normal side in 3 cases. The clinical outcomes were satisfactory in 11 cases, approximately satisfactory in 8 cases, and unsatisfactory in 4 cases according to self-designed evaluation system. The operative method of repairing the soft tissue defects in the thumb with the distally-based dorsal thumb neurocutaneous vascular flap is simple, stable in anatomy, in line with the principle of proximity, and suitable for repairing thumb tip defect 3 cm in size. It can bring a good postoperative appearance of the thumb and little influence on the hand function.

Numerical simulation of aerodynamic characteristics of multi-element wing with variable flap

NASA Astrophysics Data System (ADS)

Lv, Hongyan; Zhang, Xinpeng; Kuang, Jianghong

2017-10-01

Based on the Reynolds averaged Navier-Stokes equation, the mesh generation technique and the geometric modeling method, the influence of the Spalart-Allmaras turbulence model on the aerodynamic characteristics is investigated. In order to study the typical configuration of aircraft, a similar DLR-F11 wing is selected. Firstly, the 3D model of wing is established, and the 3D model of plane flight, take-off and landing is established. The mesh structure of the flow field is constructed and the mesh is generated by mesh generation software. Secondly, by comparing the numerical simulation with the experimental data, the prediction of the aerodynamic characteristics of the multi section airfoil in takeoff and landing stage is validated. Finally, the two flap deflection angles of take-off and landing are calculated, which provide useful guidance for the aerodynamic characteristics of the wing and the flap angle design of the wing.

Scrotal reconstruction and testicular prosthetics

PubMed Central

Lucas, Jacob W.; Lester, Kyle M.; Chen, Andrew

2017-01-01

Scrotal surgery encompasses a wide-variety of surgical techniques for an even wider variety of indications. In this manuscript, we review our indications, techniques, and pit-falls for various reconstructive scrotal surgeries as-well-as surgical tips for placement of testicular prostheses. Penoscrotal webbing (PSW) is an abnormal, often-problematic distal insertion of scrotal skin onto the ventral penile shaft. There are several effective and straightforward techniques used to revise this condition, which include simple scrotoplasty, single- or double-Z-plasty, or the VY-flap scrotoplasty. Reconstruction is also commonly indicated following scrotal skin loss caused by infection, trauma, lymphedema, hidradenitis, and cancer. Although initial management of these conditions often involves scrotal skin removal, repair of expansive scrotal skin loss can be technically difficult and can be accomplished by using one of several skin flaps or skin grafting. Split-thickness skin grafting of scrotal defects can be accomplished easily, and provides durable results. PMID:28904904

Irradiated homologous tarsal plate banking: A new alternative in eyelid reconstruction. Part I. Technique and animal research

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jordan, D.R.; Tse, D.T.; Anderson, R.L.

1990-01-01

Reconstruction of full thickness eyelid defects requires the correction of both posterior lamella (tarsus, conjunctiva) and anterior lamella (skin, muscle). Tarsal substitutes including banked sclera, nasal cartilage, ear cartilage, and periosteum can be beneficial for posterior lamellar repair, while anterior lamellar replacement, including skin grafts, pedicle flaps, advancement flaps, etc., is important to cover the posterior reconstructed portion. At times, due to extensive tissue loss, the eyelid reconstruction can be particularly challenging. We have found an alternative posterior lamellar reconstructive technique utilizing irradiated homologous tarsal plate that can be particularly useful in selected cases of severe tissue loss. The experimentalmore » surgical procedure in monkeys and the histological fate of the implanted tarsus is described in Part I, and followed in Part II by our experience with this tissue in six human patients.« less

A shark attack treated in a tertiary care centre: Case report and review of the literature.

PubMed

Roy, Mélissa; Plant, Mathew A; Snell, Laura

2018-01-01

Although uncommon, shark attacks can lead to devastating outcomes for victims. Surgeons also face unique challenges during operative management such as exsanguination, shock, specific injury patterns and infections. This case report presents the management of a 39-year-old previously healthy female attacked by a shark while on vacation in Mexico. The patient sustained severe injuries to her left arm and her left thigh. She was transferred to a Canadian institution after ambiguous operative management in Mexico and presented with no clear antibiotic coverage and a Volkman's contracture of the left upper extremity. In total, the patient underwent four washouts of wounds, two split-thickness skin grafts, one free anterolateral thigh flap, and one free transverse rectus abdominus myocutaneous flap for the reconstruction and salvage of the left lower extremity. This article highlights the specifics of this case and describes important points in managing these devastating injuries.

A shark attack treated in a tertiary care centre: Case report and review of the literature

PubMed Central

Roy, Mélissa; Plant, Mathew A; Snell, Laura

2018-01-01

Although uncommon, shark attacks can lead to devastating outcomes for victims. Surgeons also face unique challenges during operative management such as exsanguination, shock, specific injury patterns and infections. This case report presents the management of a 39-year-old previously healthy female attacked by a shark while on vacation in Mexico. The patient sustained severe injuries to her left arm and her left thigh. She was transferred to a Canadian institution after ambiguous operative management in Mexico and presented with no clear antibiotic coverage and a Volkman’s contracture of the left upper extremity. In total, the patient underwent four washouts of wounds, two split-thickness skin grafts, one free anterolateral thigh flap, and one free transverse rectus abdominus myocutaneous flap for the reconstruction and salvage of the left lower extremity. This article highlights the specifics of this case and describes important points in managing these devastating injuries. PMID:29076325

Dual Endotemponade for Extensive Long-standing Cyclodialysis Using Sulcus-fixated Cionni Ring and PCIOL.

PubMed

Gupta, Shikha; Sagar, Pradeep; Gogia, Varun; Khokhar, Sudarshan; Dada, Tanuj

2016-03-01

A young patient presented with visual acuity of hand movements only, unrecordable intraocular pressure, and total cataract after trauma 12 months ago. She reported failure to improve with conservative therapy as well as a direct cycloplexy elsewhere. After cleft localization on preoperative gonioscopy, ultrasound biomicroscopy (UBM), and intraoperative gonioscopy, a partial-thickness scleral flap was fashioned at the site of maximum cleft height. Following phacoaspiration, a multipiece intraocular lens was implanted in the sulcus; its haptics aligned to the axis with maximum height of cyclodialysis. A Cionni ring placed in sulcus was sutured to sclera under the flap to provide additional tamponading effect. Postoperative UBM and gonioscopy confirmed cleft closure. Normalization of intraocular pressure was found on repeated follow-ups till 1 year (12 to 14 mm Hg). UBM showed increase in sulcus diameter, and "double indentation sign" on the ciliary body.

Single-Stage Reconstruction of Achilles Tendon and Overlying Tissue With the Extended Temporoparietal Fasciagaleal Flap--23-Year Follow-Up and the Review of the Literature.

PubMed

Dobke, Marek; Suliman, Ahmed; Mackert, Gina A; Herrera, Fernando A; Singer, Robert; Nelson, Jeffrey

2016-05-01

In the absence of an established "gold standard" for complex Achilles tendon and regional soft tissue defect reconstruction, many techniques have been advocated. Two cases describing a novel technique of successful repair with the review of literature are presented. The underlying problem consisted of Achilles tendon necrosis with local inflammation in the first case and tendon contracture with foot malposition due to a burn injury in the other. Each patient, upon debridement, had a 6-cm Achilles tendon defect with associated overlying soft tissue deficits reconstructed with an extended temporoparietal fasciagaleal flap and a split thickness skin graft. Both cases highlight the successful functional and aesthetic quality as well as the durability of concurrent vascularized tendon and soft tissue replacement and coverage in 2 distinct clinical scenarios.

A clinical evaluation of resorbable hydroxylapatite for the repair of human intra-osseous defects.

PubMed

Corsair, A

1990-01-01

One of the goals of periodontal therapy is actual hard- and soft-tissue regeneration or at least the functional repair of periodontal defects. Alloplastic materials used in the past included dense hydroxylapatite grafts which were non-resorbable and often exfoliated. A new resorbable hydroxylapatite biomaterial [OsteoGen (HA RESORB)] was used during flap surgery. After the usual initial therapy, full-thickness flaps were elevated. A through debridement of the roots and osseous defects was accomplished. The defects were measured and then filled with OsteoGen. The mean initial bone defect depth was 4.47 mm. These defects were re-evaluated by the probing of bone levels after a 4-6-month healing period. A mean of 2.26 mm of new bone fill was obtained. This represents an average fill of 51%. Seventeen of the 22 defects had 42% or more actual new bone fill. No foreign body reaction or exfoliation occurred.

Wake visualization of a heaving and pitching foil in a soap film

NASA Astrophysics Data System (ADS)

Muijres, Florian T.; Lentink, David

2007-11-01

Many fish depend primarily on their tail beat for propulsion. Such a tail is commonly modeled as a two-dimensional flapping foil. Here we demonstrate a novel experimental setup of such a foil that heaves and pitches in a soap film. The vortical flow field generated by the foil correlates with thickness variations in the soap film, which appear as interference fringes when the film is illuminated with a monochromatic light source (we used a high-frequency SOX lamp). These interference fringes are subsequently captured with high-speed video (500 Hz) and this allows us to study the unsteady vortical field of a flapping foil. The main advantage of our approach is that the flow fields are time and space resolved and can be obtained time-efficiently. The foil is driven by a flapping mechanism that is optimized for studying both fish swimming and insect flight inside and outside the behavioral envelope. The mechanism generates sinusoidal heave and pitch kinematics, pre-described by the non-dimensional heave amplitude (0-6), the pitch amplitude (0°-90°), the phase difference between pitch and heave (0°-360°), and the dimensionless wavelength of the foil (3-18). We obtained this wide range of wavelengths for a foil 4 mm long by minimizing the soap film speed (0.25 m s-1) and maximizing the flapping frequency range (4-25 Hz). The Reynolds number of the foil is of order 1,000 throughout this range. The resulting setup enables an effective assessment of vortex wake topology as a function of flapping kinematics. The efficiency of the method is further improved by carefully eliminating background noise in the visualization (e.g., reflections of the mechanism). This is done by placing mirrors at an angle behind the translucent film such that the camera views the much more distant and out-of-focus reflections of the black laboratory wall. The resulting high-quality flow visualizations require minimal image processing for flow interpretation. Finally, we demonstrate the effectiveness of our setup by visualizing the vortex dynamics of the flapping foil as a function of pitch amplitude by assessing the symmetry of the vortical wake.

Wake visualization of a heaving and pitching foil in a soap film

NASA Astrophysics Data System (ADS)

Muijres, Florian T.; Lentink, David

Many fish depend primarily on their tail beat for propulsion. Such a tail is commonly modeled as a twodimensional flapping foil. Here we demonstrate a novel experimental setup of such a foil that heaves and pitches in a soap film. The vortical flow field generated by the foil correlates with thickness variations in the soap film, which appear as interference fringes when the film is illuminated with a monochromatic light source (we used a high-frequency SOX lamp). These interference fringes are subsequently captured with high-speed video (500 Hz) and this allows us to study the unsteady vortical field of a flapping foil. The main advantage of our approach is that the flow fields are time and space resolved and can be obtained time-efficiently. The foil is driven by a flapping mechanism that is optimized for studying both fish swimming and insect flight inside and outside the behavioral envelope. The mechanism generates sinusoidal heave and pitch kinematics, pre-described by the non-dimensional heave amplitude (0-6), the pitch amplitude (0° - 90°), the phase difference between pitch and heave (0° - 360°), and the dimensionless wavelength of the foil (3-18). We obtained this wide range of wavelengths for a foil 4 mm long by minimizing the soap film speed (0.25 m s- 1) and maximizing the flapping frequency range (4-25 Hz). The Reynolds number of the foil is of order 1,000 throughout this range. The resulting setup enables an effective assessment of vortex wake topology as a function of flapping kinematics. The efficiency of the method is further improved by carefully eliminating background noise in the visualization (e.g., reflections of the mechanism). This is done by placing mirrors at an angle behind the translucent film such that the camera views the much more distant and out-of-focus reflections of the black laboratory wall. The resulting high-quality flow visualizations require minimal image processing for flow interpretation. Finally, we demonstrate the effectiveness of our setup by visualizing the vortex dynamics of the flapping foil as a function of pitch amplitude by assessing the symmetry of the vortical wake.

Upper Arch Flap Combined with Extended Incision of Lower Eyelid: A Modified Epicanthoplasty in Correcting Epicanthus.

PubMed

Zhang, Song; Xue, Hongyu

2018-06-19

The epicanthus, a lengthways cambered skinfold around the inner canthus, is particularly common in Orientals. The purpose of this study was to evaluate the surgical outcomes for patients with epicanthus after the application of a new surgical technique. A total of 753 patients with epicanthus underwent epicanthoplasty in our hospital from October 2009 to March 2017 and were enrolled in this study. All patients were treated with upper arch flap combined with extended incision of the lower eyelid surgical method, and the effects of the surgery were assessed by photographic analysis and satisfaction surveys. After the surgery, the eyelids of patients were elongated, and their inner canthi diameter was shortened without recurrence in the epicanthus. For 3.32% of the patients, there was a nonuniform edge thickness of the lower eyelid incision; for 8.23% of the patients, there was a slightly lighter skin color in the rest of quondam arch flap. Six months after the surgery, the incision scar was not obvious for all patients, and most of the patients (90.31%) were satisfied with the effect of the surgery. The upper arch flap combined with extended incision of the lower eyelid surgical method, a simple and effective surgical correction method, obtained a good cosmetic result with more secluded scar and high satisfaction for patients with epiblepharon. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Salvage of the lower limb after a full thickness burn with loss of the knee extensor mechanism: a case report.

PubMed

Sarraf, Khaled M; Atherton, Duncan D; Jayaweera, Asantha R; Gibbons, Charles E; Jones, Isabel

2013-04-01

We report on a 79-year-old woman who underwent salvage of the knee and lower leg using a Whichita Fusion Nail for knee arthrodesis, combined with a medial gastrocnemius muscle flap for a 3% contact burn that resulted in loss of the extensor mechanism. This provided an alternative to above-knee amputation when extensor mechanism reconstruction was not feasible.

Bistable flapping of flexible flyers in oscillatory flow

NASA Astrophysics Data System (ADS)

Huang, Yangyang; Kanso, Eva

2016-11-01

Biological and bio-inspired flyers move by shape actuation. The direct control of shape variables for locomotory purposes is well studied. Less is known about indirect shape actuation via the fluid medium. Here, we consider a flexible Λ-flyer in oscillatory flow that is free to flap and rotate around its fixed apex. We study its motion in the context of the inviscid vortex sheet model. We first analyze symmetric flapping about the vertical axis of gravity. We find that there is a finite value of the flexibility that maximizes both the flapping amplitude and elastic energy storage. Our results show that rather than resonance, the flyer relies on fluidic effects to optimize these two quantities. We then perturb the flyer away from the vertical and analyze its stability. Four distinct types of rolling behavior are identified: mono-stable, bistable, bistable oscillatory rotations and chaotic dynamics. We categorize these types of behavior in terms of the flyer's and flow parameters. In particular, the transition from mono-stable to bistable behavior occurs at a constant value of the product of the flow amplitude and acceleration. This product can be interpreted as the ratio of fluidic drag to gravity, confirming the fluid role in this transition.

Implementation of a Trailing-Edge Flap Analysis Model in the NASA Langley CAMRAD.MOD1/Hires Program

NASA Technical Reports Server (NTRS)

Charles, Bruce

1999-01-01

Continual advances in rotorcraft performance, vibration and acoustic characteristics are being sought by rotary-wing vehicle manufacturers to improve efficiency, handling qualities and community noise acceptance of their products. The rotor system aerodynamic and dynamic behavior are among the key factors which must be addressed to meet the desired goals. Rotor aerodynamicists study how airload redistribution impacts performance and noise, and seek ways to achieve better airload distribution through changes in local aerodynamic response characteristics. One method currently receiving attention is the use of trailing-edge flaps mounted on the rotor blades to provide direct control of a portion of the spanwise lift characteristics. The following work describes the incorporation of a trailing-edge flap model in the CAMRAD.Mod1/FHUS comprehensive rotorcraft analysis code. The CAM-RAD.Mod1/HIRES analysis consists of three separate executable codes. These include the comprehensive trim analysis, CAMRAD.Mod1, the Indicial Post-Processor, IPP, for high resolution airloads, and AIRFOIL, which produces the rotor airfoil tables from input airfoil section characteristics. The modifications made to these components permitting analysis of flapped rotor configurations are documented herein along with user instructions detailing the new input variables and operational notes.

Influence of dynamic inflow on the helicopter vertical response

NASA Technical Reports Server (NTRS)

Chen, Robert T. N.; Hindson, William S.

1986-01-01

A study was conducted to investigate the effects of dynamic inflow on rotor-blade flapping and vertical motion of the helicopter in hover. Linearized versions of two dynamic inflow models, one developed by Carpenter and Fridovich and the other by Pitt and Peters, were incorporated in simplified rotor-body models and were compared for variations in thrust coefficient and the blade Lock number. In addition, a comparison was made between the results of the linear analysis, and the transient and frequency responses measured in flight on the CH-47B variable-stability helicopter. Results indicate that the correlations are good, considering the simplified model used. The linear analysis also shows that dynamic inflow plays a key role in destabilizing the flapping mode. The destabilized flapping mode, along with the inflow mode that the dynamic inflow introduces, results in a large initial overshoot in the vertical acceleration response to an abrupt input in the collective pitch. This overshoot becomes more pronounced as either the thrust coefficient or the blade Lock number is reduced. Compared with Carpenter's inflow model, Pitt's model tends to produce more oscillatory responses because of the less stable flapping mode predicted by it.

Distal scar-to-midline distance in pilonidal Limberg flap surgery is a recurrence-promoting factor: A multicenter, case-control study.

PubMed

Kaplan, Mehmet; Ozcan, Onder; Bilgic, Ethem; Kaplan, Elif Tugce; Kaplan, Tugba; Kaplan, Fatma Cigdem

2017-11-01

The Limberg flap (LF) procedure is widely performed for the treatment of sacrococcygeal pilonidal sinus (SPS); however, recurrences continues to be observed. The aim of this study was to assess the relationship between LF designs and the risk of SPS recurrence. Sixty-one cases with recurrent disease (study group) and 194 controls, with a minimum of 5 recurrence-free years following surgery (control group), were included in the study. LF reconstructions performed in each group were classified as off-midline closure (OMC) and non-OMC types. Subsequently, the 2 groups were analyzed. After adjustment for all variables, non-OMC types showed the most prominent correlation with recurrence, followed by interrupted suturing type, family history of SPS, smoking, prolonged healing time, and younger age. The best cut-off value for the critical distance from the midline was found to be 11 mm (with 72% sensitivity and 95% specificity for recurrence). We recommend OMC modifications, with the flap tailored to create a safe margin of at least 2 cm between the flap borders and the midline. Copyright © 2017 Elsevier Inc. All rights reserved.

Reconstruction of the first web space in symbrachydactyly using the reverse radial forearm flap.

PubMed

Gülgönen, Ayan; Güdemez, Eftal

2007-02-01

To present a new approach for the reconstruction of severe first web contractures using a distally based reverse radial forearm flap in symbrachydactyly patients. This study included 6 hands in 5 patients. Subjective evaluation included appearance, parent satisfaction (and patient satisfaction when appropriate), and ability to perform daily activities such as thumb-index grasp and pinch at follow-up evaluations. We measured the angle between the first and second rays using a goniometer at maximum radial abduction, and pinch and grasp strengths were evaluated as an objective assessment. The average follow-up period was 2 years. All parents and patients were happy with the aesthetic appearance. They were completely satisfied in their daily living activities. The average first web angle measurement was 56 degrees . An average of 39 degrees of improvement of web measurement was achieved. For the unilateral 4 patients, the average pinch strength measurement was 80% of the normal contralateral hand and the grip strength was 75% of the normal contralateral hand. The reverse radial forearm flap was found to be a safe and simple method in the reconstruction of severe first web contractures in symbrachydactyly patients. This method provided good coverage of appropriate thickness and skin quality, and supple soft tissue that filled the first web space. Therapeutic IV.

Predictors of salivary fistula after total laryngectomy.

PubMed

Sousa, Alexandre de Andrade; Porcaro-Salles, José Maria; Soares, João Marcos Arantes; de Moraes, Gustavo Meyer; Carvalho, Jomar Rezende; Silva, Guilherme Souza; Savassi-Rocha, Paulo Roberto

2013-01-01

To evaluate the incidence of pharyngocutaneous fistula after total laryngectomy and try to identify its predictors. From May 2005 to April 2010, 93 patients underwent total laryngectomy. We evaluated complications during and after surgery and compared them with the following variables: gender, nutritional status, previous tracheotomy, tumor location, type of surgery, TNM staging, prior treatment with chemotherapy and/or radiotherapy, use of flaps for reconstruction and surgical margin. All patients presented with advanced neoplastic disease according to TNM. 14 (15.1%) patients developed postoperative salivary fistula. The mean time to onset of salivary fistula was 3.5 days, with a standard deviation of 13.7 days. Comparing salivary fistula with TNM variables, type of operation and neck dissection, prior tracheotomy, use of flap, preoperative radio and chemotherapy and surgical margin, there was no statistically significant difference (p> 0,05). The incidence of salivary fistula was 15.1% and no predictive factor for its formation was found.

Observations on Leading-Edge Vortex Development

NASA Astrophysics Data System (ADS)

Glenn, Michael; Lang, Amy; Wahidi, Redha; Wilroy, Jacob

2016-11-01

Most of an insect's lift comes from the leading edge vortex (LEV) that they produce when flapping their wings. There are many variables that make a LEV either stronger or weaker such as: roughness from the scales on their wings, angle of attack (AoA) of wing, size of the wing, and speed of the wing during flapping motion. Experiments were conducted to study LEV development to gain a better understanding of butterfly flight and the importance of LEV formation. The variables emphasized in this particular experiment were the chord length Reynolds numbers. Two smooth plates of 4 inches and 7 inches were compared in this experiment with Re of 1500 and 3000. Matlab was used to track the LEV location and calculate the vorticity and circulation magnitudes. Differences in LEV vortex strength as a function of chord length will be presented. Funding was provided by NSF REU site Grant EEC 1358991 and CBET Grant 1628600.

The vascularized groin lymph node flap (VGLN): Anatomical study and flap planning using multi-detector CT scanner. The golden triangle for flap harvesting.

PubMed

Zeltzer, Assaf A; Anzarut, Alexander; Braeckmans, Delphine; Seidenstuecker, Katrin; Hendrickx, Benoit; Van Hedent, Eddy; Hamdi, Moustapha

2017-09-01

A growing number of surgeons perform lymph node transfers for the treatment of lymphedema. When harvesting a vascularized lymph node groin flap (VGLNF) one of the major concerns is the potential risk of iatrogenic lymphedema of the donor-site. This article helps understanding of the lymph node distribution of the groin in order to minimize this risk. Fifty consecutive patients undergoing abdominal mapping by multi-detector CT scanner were included and 100 groins analyzed. The groin was divided in three zones (of which zone II is the safe zone) and lymph nodes were counted and mapped with their distances to anatomic landmarks. Further node units were plotted and counted. The average age was 48 years. A mean number of nodes of 6.5/groin was found. In zone II, which is our zone of interest a mean of 3.1 nodes were counted with a mean size of 7.8 mm. In three patients no nodes were found in zone II. In five patients nodes were seen in zone II but were not sufficient in size or number to be considered a lymph node unit. On average the lymph node unit in zone II was found to be 48.3 mm from the pubic tubercle when projected on a line from the pubic tubercle to the anterior superior iliac spine, 16.0 mm caudal to this line, and 20.4 mm above the groin crease. On average the lymph node unit was a mean of 41.7 mm lateral to the SCIV-SIEV confluence. This study provides increased understanding of the lymphatic anatomy in zone II of the groin flap and suggests a refined technique for designing the VGLNF. As with any flap there is a degree of individual patient variability. However, having information on the most common anatomy and flap design is of great value. © 2017 Wiley Periodicals, Inc.

Three-Year Outcome of Fixed Partial Rehabilitations Supported by Implants Inserted with Flap or Flapless Surgical Techniques.

PubMed

Maló, Paulo; de Araújo Nobre, Miguel; Lopes, Armando

2016-07-01

The aim of this prospective clinical study was to evaluate the 3-year outcome of fixed partial prostheses supported by implants with immediate provisionalization without occlusal contacts inserted in predominantly soft bone with flap and flapless protocols. Forty-one patients partially rehabilitated with 72 NobelSpeedy implants (51 maxillary; 21 mandibular) were consecutively included and treated with a flapless surgical protocol (n = 20 patients; 32 implants) and flapped surgical protocol (n = 21 patients; 40 implants). Primary outcome measure was implant survival; secondary outcome measures were marginal bone resorption (comparing the bone levels at 1 and 3 years with baseline) and the incidence of biological, mechanical, and esthetic complications. Survival was computed through life tables; descriptive statistics were applied to the remaining variables of interest. Eight patients with eight implants dropped out of the study. One implant failed in one patient (flapless group) giving an overall cumulative survival rate (CSR) of 98.6%. No failures were noted with the flapped protocol (CSR 100%), while for the implants placed with the flapless surgical technique, a 96.9% CSR was registered. The overall average marginal bone resorption at 3 years was 1.37 mm (SD = 0.94 mm), with 1.14 mm (SD = 0.49 mm) and 1.60 mm (SD = 1.22 mm) for the flap and flapless groups, respectively. Mechanical complications occurred in nine patients (n = 5 patients in the flapless group; n = 4 patients in the flap group). Implant infection was registered in three implants and three patients (flapless group), who exhibited inadequate oral hygiene levels. Partial edentulism rehabilitation through immediate provisionalization fixed prosthesis supported by dental implants inserted through flap or flapless surgical techniques in areas of predominantly soft bone was viable at 3 years of follow-up. The limitations and risks of the "free-hand" method in flapless surgery should be considered when planning implant-supported fixed prosthetic reconstructions. © 2015 by the American College of Prosthodontists.

Factors Influencing the Incidence of Severe Complications in Head and Neck Free Flap Reconstructions

PubMed Central

Broome, Martin; Juilland, Naline; Litzistorf, Yann; Monnier, Yan; Sandu, Kishore; Pasche, Philippe; Plinkert, Peter K.; Federspil, Philippe A.

2016-01-01

Background: Complications after head and neck free-flap reconstructions are detrimental and prolong hospital stay. In an effort to identify related variables in a tertiary regional head and neck unit, the microvascular reconstruction activity over the last 5 years was captured in a database along with patient-, provider-, and volume-outcome–related parameters. Methods: Retrospective cohort study (level of evidence 3), a modified Clavien-Dindo classification, was used to assess severe complications. Results: A database of 217 patients was created with consecutively reconstructed patients from 2009 to 2014. In the univariate analysis of severe complications, we found significant associations (P < 0.05) between type of flap used, American Society of Anesthesiologists classification, T-stage, microscope use, surgeon, flap frequency, and surgeon volume. Within a binomial logistic regression model, less frequently versus frequently performed flap (odds ratio [OR] = 3.2; confidence interval [CI] = 2.9–3.5; P = 0.000), high-volume versus low-volume surgeon (OR = 0.52; CI = −0.22 to 0.82; P = 0.007), and ASA classification (OR = 2.9; CI = 2.4–3.4; P = 0.033) were retained as independent predictors of severe complications. In a Cox-regression model, surgeon (P = 0.011), site of reconstruction (P = 0.000), T-stage (P = 0.001), and presence of severe complications (P = 0.015) correlated with a prolonged hospitalization. Conclusions: In this study, we identified a correlation of patient-related factors with severe complications (ASA score) and prolonged hospital stay (T-stage, site). More importantly, we identified several provider- (surgeon) and volume-related (frequency with which a flap was performed and high-volume surgeon) factors as predictors of severe complications. Our data indicate that provider- and volume-related parameters play an important role in the outcome of microvascular free-flap procedures in the head and neck region. PMID:27826458

Coronally advanced flap and connective tissue graft with or without plasma rich in growth factors (PRGF) in treatment of gingival recession

PubMed Central

Jenabian, Niloofar; Motallebnejad, Mina; Zahedi, Ehsan; Angelov, Nikola

2018-01-01

Background Several researchers have tried to improve the results of gingival recession treatment techniques. One of the methods is to use growth factors The present study was undertaken to evaluate the effect of CAF (coronally advanced flap) + CTG (connective tissue graft) + PRGF (plasma rich in growth factors) in the treatment of Miller Class I buccal gingival recession. Material and Methods Twenty-two teeth with Miller Class I gingival recession in 6 patients 26 ‒ 47 years of age were included in a split-mouth designed randomized controlled trial (RCT). In each patient, one side was treated with CAF + CTG + PRGF (test) and the other side was treated with CAF + CTG (control). The following parameters were measured before surgery and up to 6 months after surgery on the mid-buccal surface of the tooth: keratinized tissue width (KTW), clinical attachment level (CAL), probing depth (PD), vertical recession depth (VRD), recession depth (RD), gingival thickness (GT), root coverage in percentage (RC%) and the distance between the CEJ and mucogingival junction (MGJL). Data were analyzed with paired t-test and repeated measures ANOVA. Results After 6 months noticeable improvements were observed in both groups in all the variables measured except for PD; however, the differences between the two groups were not significant. RC% was 80 ± 25% and 67 ± 28% in the test and control groups, respectively, after 6 months. Conclusions Both CAF + CTG + PRGF and CAF + CTG treatment modalities resulted in favorable root coverage; however, the addition of PRGF added no measurable significant effect. Key words:Connective tissue graft, dental root coverage, gingival recession, growth factors, mucogingival surgery, periodontal plastic surgery. PMID:29849966

Coronally advanced flap and connective tissue graft with or without plasma rich in growth factors (PRGF) in treatment of gingival recession.

PubMed

Jenabian, Niloofar; Motallebnejad, Mina; Zahedi, Ehsan; Sarmast, Nima D; Angelov, Nikola

2018-05-01

Several researchers have tried to improve the results of gingival recession treatment techniques. One of the methods is to use growth factors The present study was undertaken to evaluate the effect of CAF (coronally advanced flap) + CTG (connective tissue graft) + PRGF (plasma rich in growth factors) in the treatment of Miller Class I buccal gingival recession. Twenty-two teeth with Miller Class I gingival recession in 6 patients 26 ‒ 47 years of age were included in a split-mouth designed randomized controlled trial (RCT). In each patient, one side was treated with CAF + CTG + PRGF (test) and the other side was treated with CAF + CTG (control). The following parameters were measured before surgery and up to 6 months after surgery on the mid-buccal surface of the tooth: keratinized tissue width (KTW), clinical attachment level (CAL), probing depth (PD), vertical recession depth (VRD), recession depth (RD), gingival thickness (GT), root coverage in percentage (RC%) and the distance between the CEJ and mucogingival junction (MGJL). Data were analyzed with paired t-test and repeated measures ANOVA. After 6 months noticeable improvements were observed in both groups in all the variables measured except for PD; however, the differences between the two groups were not significant. RC% was 80 ± 25% and 67 ± 28% in the test and control groups, respectively, after 6 months. Both CAF + CTG + PRGF and CAF + CTG treatment modalities resulted in favorable root coverage; however, the addition of PRGF added no measurable significant effect. Key words: Connective tissue graft, dental root coverage, gingival recession, growth factors, mucogingival surgery, periodontal plastic surgery.

Optimal flapping wing for maximum vertical aerodynamic force in hover: twisted or flat?

PubMed

Phan, Hoang Vu; Truong, Quang Tri; Au, Thi Kim Loan; Park, Hoon Cheol

2016-07-08

This work presents a parametric study, using the unsteady blade element theory, to investigate the role of twist in a hovering flapping wing. For the investigation, a flapping-wing system was developed to create a wing motion of large flapping amplitude. Three-dimensional kinematics of a passively twisted wing, which is capable of creating a linearly variable geometric angle of attack (AoA) along the wingspan, was measured during the flapping motion and used for the analysis. Several negative twist or wash-out configurations with different values of twist angle, which is defined as the difference in the average geometric AoAs at the wing root and the wing tip, were obtained from the measured wing kinematics through linear interpolation and extrapolation. The aerodynamic force generation and aerodynamic power consumption of these twisted wings were obtained and compared with those of flat wings. For the same aerodynamic power consumption, the vertical aerodynamic forces produced by the negatively twisted wings are approximately 10%-20% less than those produced by the flat wings. However, these twisted wings require approximately 1%-6% more power than flat wings to produce the same vertical force. In addition, the maximum-force-producing twisted wing, which was found to be the positive twist or wash-in configuration, was used for comparison with the maximum-force-producing flat wing. The results revealed that the vertical aerodynamic force and aerodynamic power consumption of the two types of wings are almost identical for the hovering condition. The power loading of the positively twisted wing is only approximately 2% higher than that of the maximum-force-producing flat wing. Thus, the flat wing with proper wing kinematics (or wing rotation) can be regarded as a simple and efficient candidate for the development of hovering flapping-wing micro air vehicle.

Intraoperative use of indocyanine green angiography for selecting the more reliable perforator of the anterolateral thigh flap: A comparison study.

PubMed

La Padula, Simone; Hersant, Barbara; Meningaud, Jean Paul

2018-03-30

Anatomical variability of anterolateral thigh flap (ALT) perforators has been reported. The aim of this study is to assess if the use of intraoperative indocyanine green angiography (iICGA) can help surgeons to choose the ALT flap best perforator to be preserved. A retrospective study was conducted in 28 patients with open tibial fracture, following a road traffic crash, who had undergone ALT flap. Patients were classified into two groups: ICGA group (iICGA was used to select the more reliable perforator) and control group. The mean tissue loss size of the ICGA group (n = 13, 11 men and 2 women, mean age: 52 ± 6 years) was of 16.6 cm × 12.2 cm. The mean defect size of the control group (n = 15, 14 men and 1 women, mean age: 50 ± 5.52 years) was of 15.3 cm × 11.1 cm. Statistical analysis was performed to analyze and compare the results. ICGA allowed preserving only the most functional perforator, that provided the best ALT flap perfusion in 10 out of the 13 cases (77%). ICGA allowed a significant operative time reduction (160 ± 23 vs. 202 ± 48 minutes; P < .001). One case of distal necrosis was observed in the ICGA group (mean follow-up 12.3 months), while partial skin necrosis occurred in three cases of the control group (mean follow-up 13.1 months); P = .35. No additional coverage was required and a successful bone healing was observed in both groups. These findings suggest that iICGA is an effective method that allows to select the most reliable ALT flap perforators and to reduce operative time. © 2018 Wiley Periodicals, Inc.

Hard and soft tissue augmentation in a postorthodontic patient: a case report.

PubMed

Bonacci, Fred J

2011-02-01

A combination of hard and soft tissue grafting is used to augment a thin biotype. A 26-year-old woman with mandibular anterior flaring and Miller Class I and III recessions requested interceptive treatment. Surgery included a full-thickness buccal flap, intramarrow penetrations, bone graft placement, and primary flap closure. Postoperative visits were at 2 and 4 weeks and 2, 3, and 6 months. Stage-two surgery consisted of submerged connective tissue graft placement. Postoperative visits were completed at 2, 4, 6, and 8 weeks and 1 year. Follow-up was completed 3 years after the initial surgery. Interradicular concavities were resolved and gingival biotype was augmented. Soft tissue recession remained at 6 months. Reentry revealed clinical labial plate augmentation; 2 mm was achieved at the lateral incisors and the left central incisor and 3 mm was achieved at the right canine. No bone augmentation was achieved on the left canine and right central incisor. The dehiscence at the right central incisor appeared narrower. Overall, a 2- to 3-mm gain in alveolar bone thickness/height was observed. Two months after stage-two surgery, near complete root coverage was achieved; 1 mm of recession remained on the left central incisor. There was a soft tissue thickness gain of 2 mm without any visual difference in keratinized tissue height. Interradicular concavities were eliminated; the soft tissue was augmented and the gingival biotype was altered. Interdental soft tissue craters remained. One year after connective tissue graft placement, there was near complete root coverage at the left central incisor, which at 2 months experienced residual recession. Interradicular concavities and interdental soft tissue craters were eliminated with soft tissue augmentation, including clinical reestablishment of the mucogingival junction. Clinical stability remained 3 years after the initial surgery, with the patient noting comfort during mastication and routine oral hygiene. A clinical increase in labial plate thickness, in conjunction with soft tissue augmentation, appears to provide for continued stability and decreased potential for future clinical attachment loss.

A test of a vortex method for the computation of flap side edge noise

NASA Technical Reports Server (NTRS)

Martin, James E.

1995-01-01

Upon approach to landing, a major source location of airframe noise occurs at the side edges of the part span, trailing edge flaps. In the vicinity of these flaps, a complex arrangement of spanwise flow with primary and secondary tip vortices may form. Each of these vortices is observed to become fully three-dimensional. In the present study, a numerical model is developed to investigate the noise radiated from the side edge of a flap. The inherent three-dimensionality of this flow forces us to carefully consider a numerical scheme which will be both accurate in its prediction of the flow acoustics and also computationally efficient. Vortex methods have offered a fast and efficient means of simulating many two and three-dimensional, vortex dominated flows. In vortex methods, the time development of the flow is tracked by following exclusively the vorticity containing regions. Through the Biot-Savart law, knowledge of the vorticity field enables one to obtain flow quantities at any desired location during the flow evolution. In the present study, a numerical procedure has been developed which incorporates the Lagrangian approach of vortex methods into a calculation for the noise radiated by a flow-surface interaction. In particular, the noise generated by a vortex in the presence of a flat half plane is considered. This problem serves as a basic model of flap edge flow. It also permits the direct comparison between our computed results and previous acoustic analyses performed for this problem. In our numerical simulations, the mean flow is represented by the complex potential W(z) = Aiz(exp l/2), which is obtained through conformal mapping techniques. The magnitude of the mean flow is controlled by the parameter A. This mean flow has been used in the acoustic analysis by Hardin and is considered a reasonable model of the flow field in the vicinity of the edge and away from the leading and trailing edges of the flap. To represent the primary vortex which occurs near the flap, a point vortex is introduced just below the flat half plane. Using a technique from panel methods, boundary conditions on the flap surface are satisfied by the introduction of a row of stationary point vortices along the extent of the flap. At each time step in the calculation, the strength of these vortices is chosen to eliminate the normal velocity at intermediary collocation points. The time development of the overall flow field is then tracked using standard techniques from vortex methods. Vortex trajectories obtained through this computation are in good agreement with those predicted by the analytical solution given by Hardin, thus verifying the viability of this procedure for more complex flow arrangements. For the flow acoustics, the Ffowcs Williams-Hawkings equation is numerically integrated. This equation supplies the far field acoustic pressure based upon pressures occurring along the flap surface. With our vortex method solution, surface pressures may be obtained with exceptional resolution. The Ffowcs Williams-Hawkings equation is integrated using a spatially fourth order accurate Simpson's rule. Rational function interpolation is used to obtain the surface pressures at the appropriate retarded times. Comparisons between our numerical results for the acoustic pressure and those predicted by the Hardin analysis have been made. Preliminary results indicate the need for an improved integration technique. In the future, the numerical procedure developed in this study will be applied to the case of a rectangular flap of finite thickness and ultimately modified for application to the fully three-dimensional problem.

Controlling the development of coherent structures in high speed jets and the resultant near field

NASA Astrophysics Data System (ADS)

Speth, Rachelle

This work uses Large-Eddy Simulations to examine the effect of actuator parameters and jet exit properties on the evolution of coherent structures and their impact on the near-acoustic field without and with control. For the controlled cases, Localized Arc Filament Plasma Actuators (LAFPAs) are considered, and modeled with a simple heating approach that successfully reproduces the main observations and trends of experiments. A parametric study is first conducted, using the flapping mode (m = +/-1), to investigate the sensitivity of the results to various actuator parameters including: actuator model temperature, actuator duty cycle, and excitation frequency. It is shown by considering a Mach 1.3 jet at Reynolds number of 1 x 106 that the response of the jet is relatively insensitive to actuator model temperature within the limits of the experimentally measured temperature values. Furthermore, duty cycles in the range of 20%--90% were observed to be effective in reproducing the characteristic coherent structures of the flapping mode. Next, jet flow parameters were explored to determine the control authority under different operating conditions. To begin, the effect of the laminar nozzle exit boundary layer thickness was examined by varying its value from essentially uniform flow to 25% of the diameter. In the absence of control, the distance between the nozzle lip and the initial appearance of breakdown is proportional to the boundary-layer thickness, which is consistent with theory and previous results obtained by other researchers at Mach 0.9. The second flow parameter studied was the effect of Reynolds number on a Mach 1.3 jet controlled by the flapping mode at an excitation Strouhal number of 0.3. The higher Reynolds number (Re=1,100,000) jet exhibited reduced control authority compared to the Re=100,000 jet. Like the effect of increasing the nozzle exit boundary layer thickness, increasing the Reynolds number cause a reduction in spreading on the flapping plane and an increase on the non-flapping plane. Therefore, these thicker layers and higher Reynolds number jets may require actuators with a higher energy input (i.e. higher duty cycle, higher actuator temperature, more actuators) to ensure the excitation of the flow instability. The final parameter studied is the effect of Mach number on the development and decay of large scale structures for no-control and control cases for Mach 0.9 and Mach 1.3 jets. For this exercise, the axisymmetric mode (m=0) was considered at excitation frequencies of St=0.05, 0.15, and 0.25, with emphasis on the evolution of coherent structures and their effects on the resultant near field pressure map. Without control, the two jets have similar shear layer growth until the end of the potential core length of the subsonic case, at which point the subsonic jet spreads at a higher rate. For the controlled cases, relatively larger streamwise hairpin vortices have been noted for the subsonic cases than the supersonic cases resulting in stronger entrainment of the ambient fluid. This increased entrainment in the subsonic cases causes a reduction in the normalized convective velocity resulting in similar normalized values to that of the supersonic cases. As the excitation frequency is increased, more hairpin vortices are present and the normalized convective velocity is reduced for both subsonic and supersonic cases. (Abstract shortened by ProQuest.).

Keratoprosthesis: preliminary results of an artificial corneal button as a full-thickness implant in the rabbit model.

PubMed

Hicks, C R; Chirila, T V; Dalton, P D; Clayton, A B; Vijayasekaran, S; Crawford, G J; Constable, I J

1996-08-01

To develop a prototype artificial cornea and evaluate it in the rabbit model. Hydrogel core-and-skirt keratoprostheses were made and were inserted as full-thickness implants covered with conjunctival flaps in the right eyes of eight rabbits. Peroperative complications related to inadequate mechanical strength led to failure in the early postoperative period in three animals, one was euthanased for an unrelated reason and the remaining four have been successful for up to 16 weeks' follow-up. Full-thickness implantation of an artificial cornea, analogous to penetrating keratoplasty, has been achieved in the rabbit model. Histological findings confirm that integration of the prosthesis with host tissue occurs. The main complications encountered in this preliminary series were related to inadequate strength of the sponge skirt of this prototype device. Work in our laboratories is now concentrated upon improving the mechanical qualities of the hydrogel skirt and on the enhancement of biointegration.

Soft tissue augmentation around osseointegrated and uncovered dental implants: a systematic review.

PubMed

Bassetti, Renzo G; Stähli, Alexandra; Bassetti, Mario A; Sculean, Anton

2017-01-01

The aim was to compile the current knowledge about the efficacy of different soft tissue correction methods around osseointegrated, already uncovered and/or loaded (OU/L) implants with insufficient soft tissue conditions. Procedures to increase peri-implant keratinized mucosa (KM) width and/or soft tissue volume were considered. Screening of two databases: MEDLINE (PubMed) and EMBASE (OVID), and manual search of articles were performed. Human studies reporting on soft tissue augmentation/correction methods around OU/L implants up to June 30, 2016, were considered. Quality assessment of selected full-text articles to weight risk of bias was performed using the Cochrane collaboration's tool. Overall, four randomized controlled trials (risk of bias = high/low) and five prospective studies (risk of bias = high) were included. Depending on the surgical techniques and graft materials, the enlargement of keratinized tissue (KT) ranged between 1.15 ± 0.81 and 2.57 ± 0.50 mm. The apically positioned partial thickness flap (APPTF), in combination with a free gingival graft (FGG), a subepithelial connective tissue graft (SCTG), or a xenogeneic graft material (XCM) were most effective. A coronally advanced flap (CAF) combined with SCTG in three, combined with allogenic graft materials (AMDA) in one, and a split thickness flap (STF) combined with SCTG in another study showed mean soft tissue recession coverage rates from 28 to 96.3 %. STF combined with XCM failed to improve peri-implant soft tissue coverage. The three APPTF-techniques combined with FGG, SCTG, or XCM achieved comparable enlargements of peri-implant KT. Further, both STF and CAF, both in combination with SCTG, are equivalent regarding recession coverage rates. STF + XCM and CAF + AMDA did not reach significant coverage. In case of soft tissue deficiency around OU/L dental implants, the selection of both an appropriate surgical technique and a suitable soft tissue graft material is of utmost clinical relevance.

Successful pacing using a batteryless sunlight-powered pacemaker.

PubMed

Haeberlin, Andreas; Zurbuchen, Adrian; Schaerer, Jakob; Wagner, Joerg; Walpen, Sébastien; Huber, Christoph; Haeberlin, Heinrich; Fuhrer, Juerg; Vogel, Rolf

2014-10-01

Today's cardiac pacemakers are powered by batteries with limited energy capacity. As the battery's lifetime ends, the pacemaker needs to be replaced. This surgical re-intervention is costly and bears the risk of complications. Thus, a pacemaker without primary batteries is desirable. The goal of this study was to test whether transcutaneous solar light could power a pacemaker. We used a three-step approach to investigate the feasibility of sunlight-powered cardiac pacing. First, the harvestable power was estimated. Theoretically, a subcutaneously implanted 1 cm(2) solar module may harvest ∼2500 µW from sunlight (3 mm implantation depth). Secondly, ex vivo measurements were performed with solar cells placed under pig skin flaps exposed to a solar simulator and real sunlight. Ex vivo measurements under real sunlight resulted in a median output power of 4941 µW/cm(2) [interquartile range (IQR) 3767-5598 µW/cm(2), median skin flap thickness 3.0 mm (IQR 2.7-3.3 mm)]. The output power strongly depended on implantation depth (ρSpearman = -0.86, P < 0.001). Finally, a batteryless single-chamber pacemaker powered by a 3.24 cm(2) solar module was implanted in vivo in a pig to measure output power and to pace. In vivo measurements showed a median output power of >3500 µW/cm(2) (skin flap thickness 2.8-3.84 mm). Successful batteryless VVI pacing using a subcutaneously implanted solar module was performed. Based on our results, we estimate that a few minutes of direct sunlight (irradiating an implanted solar module) allow powering a pacemaker for 24 h using a suitable energy storage. Thus, powering a pacemaker by sunlight is feasible and may be an alternative energy supply for tomorrow's pacemakers. Published on behalf of the European Society of Cardiology. All rights reserved. © The Author 2014. For permissions please email: journals.permissions@oup.com.

SURGICAL OUTCOME OF SIMULTANEOUS INTRAOCULAR LENS RESCUE AND SUTURELESS INTRASCLERAL TUNNEL FIXATION OF DISLOCATED INTRAOCULAR LENSES.

PubMed

Kim, Min; Lee, Dong H; Koh, Hyoung J; Lee, Sung C; Kim, Sung S

2015-07-01

To report short-term surgical outcomes of single-stage simultaneous rescue and sutureless intrascleral fixation of dislocated intraocular lens (IOLs). Sixteen eyes of 16 patients who underwent simultaneous rescue and intrascleral fixation of dislocated 3-piece IOLs were retrospectively evaluated. Partial thickness limbal-based scleral flaps (2.0 × 2.0 mm) were created, and a 22-gauge round needle was used to create a sclerotomy at 1.5 mm from the limbus under the previously created scleral flap, and a 23-gauge trans pars plana vitrectomy was performed. Bimanual maneuvers using two 23-gauge end-grasping forceps under chandelier illumination and a wide-angle viewing system enabled 1 step rescue of IOLs from the posterior vitreous cavity with 1 hand and simultaneous haptic externalization through sclerotomy with the other hand. An externalized haptic was placed into the 3-mm intrascleral tunnel created using a bent 26-gauge needle. Fibrin glue was used to fixate haptics and close the scleral flaps. Intraocular lenses were successfully rescued and sclera-fixated through intrascleral tunnels in all 16 eyes (mean age, 56.56 ± 19.89 years). The mean preoperative logarithm of the minimum angle of resolution best-corrected visual acuity was 0.92 ± 0.68, and this significantly improved at 6 months to 0.289 ± 0.36 (P = 0.003). During the follow-up period (10.1 ± 3.21 months), no significant change of endothelial cell count or central foveal thickness was noted postoperatively (P = 0.203 and P = 0.979, respectively). There were no significant postoperative complications such as IOL dislocation, IOL decentration, retinal detachment, endophthalmitis, or postoperative hypotony. Simultaneous rescue and sutureless intrascleral haptic fixation of dislocated 3-piece IOLs using bimanual maneuvers is an effective, safe, and minimally invasive surgical method to rescue and fixate the dislocated IOL without further explant.

Inverted ILM flap, free ILM flap and conventional ILM peeling for large macular holes.

PubMed

Velez-Montoya, Raul; Ramirez-Estudillo, J Abel; Sjoholm-Gomez de Liano, Carl; Bejar-Cornejo, Francisco; Sanchez-Ramos, Jorge; Guerrero-Naranjo, Jose Luis; Morales-Canton, Virgilio; Hernandez-Da Mota, Sergio E

2018-01-01

To assess closure rate after a single surgery of large macular holes and their visual recovery in the short term with three different surgical techniques. Prospective multicenter randomized controlled trial. We included treatment-naïve patients with diagnosis of large macular hole (minimum diameter of > 400 µm). All patients underwent a comprehensive ophthalmological examination. Before surgery, the patients were randomized into three groups: group A: conventional internal limiting membrane peeling, group B: inverted-flap technique and group C: free-flap technique. All study measurements were repeated within the period of 1 and 3 months after surgery. Continuous variables were assessed with a Kruskal-Wallis test, change in visual acuity was assessed with analysis of variance for repeated measurements with a Bonferroni correction for statistical significance. Thirty-eight patients were enrolled (group A: 12, group B: 12, group C: 14). The closure rate was in group A and B: 91.6%; 95% CI 61.52-99.79%. In group C: 85.71%; 95% CI 57.19-98.22%. There were no differences in the macular hole closure rate between groups ( p  = 0.85). All groups improved ≈ 0.2 logMAR, but only group B reached statistical significance ( p  < 0.007). Despite all techniques displayed a trend toward visual improvement, the inverted-flap technique seems to induce a faster and more significant recovery in the short term.

Functional sequelae following bilateral mastectomy and immediate reconstruction with latissimus dorsi flap: medium-term follow-up.

PubMed

Paolini, Guido; Amoroso, Matteo; Pugliese, Pierfrancesco; Longo, Benedetto; Santanelli, Fabio

2014-04-01

Arm morbidity following unilateral Latissimus Dorsi (LD) flap harvest is controversial and bilateral harvest is considered potentially disabling. Arm and shoulder disability was investigated in patients undergoing bilateral mastectomy and immediate LD flap reconstruction. Thirty consecutive bilateral immediate reconstructions with denervated LD flaps, performed between 2005-2009, were retrospectively analyzed. Patients were assessed for arm function by conducting the Disability of Arm, Shoulder and Hand (DASH) test, between 12-51 months after surgery (mean 23 months). Disability scores ranged from 1-100%, with 1-25% being regarded as mild dysfunction, 26-50% as moderate dysfunction, 51-75% as severe dysfunction, and 76-100% as total dysfunction. A statistical analysis was performed using the Fisher exact test and the multivariate linear regression model for variables. The Global Mean Dash score was 14.8%. Twenty-four patients presented a mild functional deficit (< 25%), while six presented a moderate one (< 50%). Five of them presented a score < 40%, while only one patient presented a score of 49.1%. Higher scores were significantly associated (p < 0.001) with major postoperative complications and lower ones with re-innervated LD flaps (p < 0.01). An insignificant functional impairment was noted in most patients, while a moderate-to-severe one was noted only in the group with complications. Greater impairment is observed in the heavy activities. The DASH test is a useful tool in terms of informing patients and helping the surgeon to choose the best surgical option.

Hydrodynamics of a flexible plate between pitching rigid plates

NASA Astrophysics Data System (ADS)

Kim, Junyoung; Kim, Daegyoum

2017-11-01

The dynamics of a flexible plate have been studied as a model problem in swimming and flying of animals and fluid-structure interaction of plants and flags. Motivated by fish schooling and an array of sea grasses, we investigate the dynamics of a flexible plate closely placed between two pitching rigid plates. In most studies on passive deformation of the flexible plate, the plate is immersed in a uniform flow or a wavy flow. However, in this study, the flexible plate experiences periodic deformation by the oscillatory flow generated by the prescribed pitching motion of the rigid plates. In our model, the pitching axes of the rigid plates and the clamping position of the flexible plate are aligned on the same line. The flexible plate shows various responses depending on length and pitching frequency of rigid plates, thickness of a flexible plate, and free-stream velocity. To find the effect of each variable on the response of the flexible plate, amplitude of a trailing edge and modal contribution of a flapping motion are compared, and flow structure around the flexible plate is examined.

Mathematical model to compare the relative tensile strength of the cornea after PRK, LASIK, and small incision lenticule extraction.

PubMed

Reinstein, Dan Z; Archer, Timothy J; Randleman, J Bradley

2013-07-01

To develop a mathematical model to estimate the relative differences in postoperative stromal tensile strength following photorefractive keratectomy (PRK), LASIK, and small incision lenticule extraction (SMILE). Using previously published data where in vitro corneal stromal tensile strength was determined as a function of depth, a mathematical model was built to calculate the relative remaining tensile strength by fitting the data with a fourth order polynomial function yielding a high correlation coefficient (R(2) = 0.930). Calculating the area under this function provided a measure of total stromal tensile strength (TTS), based only on the residual stromal layer for PRK or LASIK and the residual stromal layers above and below the lenticule interface for SMILE. Postoperative TTS was greatest after SMILE, followed by PRK, then LASIK; for example, in a 550-μm cornea after 100-μm tissue removal, postoperative TTS was 75% for SMILE (130-μm cap), 68% for PRK, and 54% for LASIK (110-μm flap). The postoperative TTS decreased for thinner corneal pachymetry for all treatment types. In LASIK, the postoperative TTS decreased with increasing flap thickness by 0.22%/μm, but increased by 0.08%/μm for greater cap thickness in SMILE. The model predicted that SMILE lenticule thickness could be approximately 100 μm greater than the LASIK ablation depth and still have equivalent corneal strength (equivalent to approximately 7.75 diopters). This mathematical model predicts that the postoperative TTS is considerably higher after SMILE than both PRK and LASIK, as expected given that the strongest anterior lamellae remain intact. Consequently, SMILE should be able to correct higher levels of myopia. Copyright 2013, SLACK Incorporated.

Experience With Wound VAC and Delayed Primary Closure of Contaminated Soft Tissue Injuries in Iraq

DTIC Science & Technology

2006-11-01

wound was definitively closed by delayed primary closure, flap mobilization, or split-thickness skin grafting . The VAC system was also used...postoperatively for 3 to 5 days over skin grafts , then removed at the bedside to assess graft take. Granulation tissue was not a prerequisite for wound closure...hospital until the closed wounds were clean and dry with good skin graft incorporation. All patients were scheduled for follow-up in our outpatient

Transonic wind tunnel test of a 14 percent thick oblique wing

NASA Technical Reports Server (NTRS)

Kennelly, Robert A., Jr.; Kroo, Ilan M.; Strong, James M.; Carmichael, Ralph L.

1990-01-01

An experimental investigation was conducted at the ARC 11- by 11-Foot Transonic Wind Tunnel as part of the Oblique Wing Research Aircraft Program to study the aerodynamic performance and stability characteristics of a 0.087-scale model of an F-8 airplane fitted with an oblique wing designed by Rockwell International. The 10.3 aspect ratio, straight-tapered wing of 0.14 thickness/chord ratio was tested at two different mounting heights above the fuselage. Additional tests were conducted to assess low-speed behavior with and without flaps, aileron effectiveness at representative flight conditions, and transonic drag divergence with 0 degree wing sweep. Longitudinal stability data were obtained at sweep angles of 0, 30, 45, 60, and 65 degrees, at Mach numbers ranging from 0.25 to 1.40. Test Reynolds numbers varied from 3.2 to 6.6 x 10 exp 6/ft. and angle of attack ranged from -5 to +18 degrees. Most data were taken at zero sideslip, but a few runs were at sideslip angles of +/- 5 degrees. The raised wing position proved detrimental overall, although side force and yawing moment were reduced at some conditions. Maximum lift coefficient with the flaps deflected was found to fall short of the value predicted in the preliminary design document. The performance and trim characteristics of the present wing are generally inferior to those obtained for a previously tested wing designed at ARC.

Treatment of gingival recession defects with a coronally advanced flap and a xenogeneic collagen matrix: a multicenter randomized clinical trial.

PubMed

Jepsen, Karin; Jepsen, Søren; Zucchelli, Giovanni; Stefanini, Martina; de Sanctis, Massimo; Baldini, Nicola; Greven, Björn; Heinz, Bernd; Wennström, Jan; Cassel, Björn; Vignoletti, Fabio; Sanz, Mariano

2013-01-01

To evaluate the clinical outcomes of the use of a xenogeneic collagen matrix (CM) in combination with the coronally advanced flap (CAF) in the treatment of localized recession defects. In a multicentre single-blinded, randomized, controlled, split-mouth trial, 90 recessions (Miller I, II) in 45 patients received either CAF + CM or CAF alone. At 6 months, root coverage (primary outcome) was 75.29% for test and 72.66% for control defects (p = 0.169), with 36% of test and 31% of control defects exhibiting complete coverage. The increase in mean width of keratinized tissue (KT) was higher in test (from 1.97 to 2.90 mm) than in control defects (from 2.00 to 2.57 mm) (p = 0.036). Likewise, test sites had more gain in gingival thickness (GT) (0.59 mm) than control sites (0.34 mm) (p = 0.003). Larger (≥3 mm) recessions (n = 35 patients) treated with CM showed higher root coverage (72.03% versus 66.16%, p = 0.043), as well as more gain in KT and GT. CAF + CM was not superior with regard to root coverage, but enhanced gingival thickness and width of keratinized tissue when compared with CAF alone. For the coverage of larger defects, CAF + CM was more effective. © 2012 John Wiley & Sons A/S.

Going skin deep: A direct comparison of penetration potential of lipid-based nanovesicles on the isolated perfused human skin flap model.

PubMed

Ternullo, Selenia; de Weerd, Louis; Holsæter, Ann Mari; Flaten, Gøril Eide; Škalko-Basnet, Nataša

2017-12-01

Phospholipid-based nanocarriers are attractive drug carriers for improved local skin therapy. In the present study, the recently developed isolated perfused human skin flap (IPHSF) model was used to directly compare the skin penetration enhancing potential of the three commonly used nanocarriers, namely conventional liposomes (CLs), deformable liposomes (DLs) and solid lipid nanoparticles (SLNs). Two fluorescent markers, calcein (hydrophilic) or rhodamine (lipophilic), were incorporated individually in the three nanosystems. The nanocarrier size ranged between 200 and 300nm; the surface charge and entrapment efficiency for both markers were dependent on the lipid composition and the employed surfactant. Both carrier-associated markers could not penetrate the full thickness human skin, confirming their suitability for dermal drug delivery. CLs exhibited higher retention of both markers on the skin surface compared to DLs and SLNs, indicating a depo formation. DLs and SLNs enabled the deeper penetration of the two markers into the skin layers. In vitro and ex vivo skin penetration studies performed on the cellophane membrane and full thickness pig/human skin, respectively, confirmed the findings. In conclusion, efficient dermal drug delivery can be achieved by optimization of a lipid nanocarrier on the suitable skin-mimicking model to assure system's accumulation in the targeted skin layer. Copyright © 2017 Elsevier B.V. All rights reserved.

Aeroelastic Wing Shaping Control Subject to Actuation Constraints.

NASA Technical Reports Server (NTRS)

Swei, Sean Shan-Min; Nguyen, Nhan

2014-01-01

This paper considers the control of coupled aeroelastic aircraft model which is configured with Variable Camber Continuous Trailing Edge Flap (VCCTEF) system. The relative deflection between two adjacent flaps is constrained and this actuation constraint is accounted for when designing an effective control law for suppressing the wing vibration. A simple tuned-mass damper mechanism with two attached masses is used as an example to demonstrate the effectiveness of vibration suppression with confined motion of tuned masses. In this paper, a dynamic inversion based pseudo-control hedging (PCH) and bounded control approach is investigated, and for illustration, it is applied to the NASA Generic Transport Model (GTM) configured with VCCTEF system.

Leading-edge vortex research: Some nonplanar concepts and current challenges

NASA Technical Reports Server (NTRS)

Campbell, J. F.; Osborn, R. F.

1986-01-01

Some background information is provided for the Vortex Flow Aerodynamics Conference and that current slender wing airplanes do not use variable leading edge geometry to improve transonic drag polar is shown. Highlights of some of the initial studies combining wing camber, or flaps, with vortex flow are presented. Current vortex flap studies were reviewed to show that there is a large subsonic data base and that transonic and supersonic generic studies have begun. There is a need for validated flow field solvers to calculate vortex/shock interactions at transonic and supersonic speeds. Many important research opportunities exist for fundamental vortex flow investigations and for designing advanced fighter concepts.

Elastically Shaped Wing Optimization and Aircraft Concept for Improved Cruise Efficiency

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Trinh, Khanh; Reynolds, Kevin; Kless, James; Aftosmis, Michael; Urnes, James, Sr.; Ippolito, Corey

2013-01-01

This paper presents the findings of a study conducted tn 2010 by the NASA Innovation Fund Award project entitled "Elastically Shaped Future Air Vehicle Concept". The study presents three themes in support of meeting national and global aviation challenges of reducing fuel burn for present and future aviation systems. The first theme addresses the drag reduction goal through innovative vehicle configurations via non-planar wing optimization. Two wing candidate concepts have been identified from the wing optimization: a drooped wing shape and an inflected wing shape. The drooped wing shape is a truly biologically inspired wing concept that mimics a seagull wing and could achieve about 5% to 6% drag reduction, which is aerodynamically significant. From a practical perspective, this concept would require new radical changes to the current aircraft development capabilities for new vehicles with futuristic-looking wings such as this concept. The inflected wing concepts could achieve between 3% to 4% drag reduction. While the drag reduction benefit may be less, the inflected-wing concept could have a near-term impact since this concept could be developed within the current aircraft development capabilities. The second theme addresses the drag reduction goal through a new concept of elastic wing shaping control. By aeroelastically tailoring the wing shape with active control to maintain optimal aerodynamics, a significant drag reduction benefit could be realized. A significant reduction in fuel burn for long-range cruise from elastic wing shaping control could be realized. To realize the potential of the elastic wing shaping control concept, the third theme emerges that addresses the drag reduction goal through a new aerodynamic control effector called a variable camber continuous trailing edge flap. Conventional aerodynamic control surfaces are discrete independent surfaces that cause geometric discontinuities at the trailing edge region. These discontinuities promote vorticities which result in drag rises as well as noise sources. The variable camber trailing edge flap concept could provide a substantial drag reduction benefit over a conventional discrete flap system. Aerodynamic simulations show a drag reduction of over 50% could be achieved with the flap concept over a conventional discrete flap system.

Rim instability of bursting thin smectic films

NASA Astrophysics Data System (ADS)

Trittel, Torsten; John, Thomas; Tsuji, Kinko; Stannarius, Ralf

2013-05-01

The rupture of thin smectic bubbles is studied by means of high speed video imaging. Bubbles of centimeter diameter and film thicknesses in the nanometer range are pierced, and the instabilities of the moving rim around the opening hole are described. Scaling laws describe the relation between film thickness and features of the filamentation process of the rim. A flapping motion of the retracting smectic film is assumed as the origin of the observed filamentation instability. A comparison with similar phenomena in soap bubbles is made. The present experiments extend studies on soap films [H. Lhuissier and E. Villermaux, Phys. Rev. Lett. 103, 054501 (2009), 10.1103/PhysRevLett.103.054501] to much thinner, uniform films of thermotropic liquid crystals.

Two-Piece Hollow Bulb Obturator for Postsurgical Partial Maxillectomy Defect in a Young Patient Revamping Lost Malar Prominence: A Clinical Report.

PubMed

Vaidya, Sharad; Parkash, Hari; Gupta, Sharad; Bhargava, Akshay; Kapoor, Charu

2016-01-01

The most frequent type of treatment for patients diagnosed with a malignant neoplasia of the oral cavity is surgical resection of the tumor. Ablative surgery may be followed by a reconstructive phase, in which the surgeon may choose between local flaps, nonvascularized bone grafts or free vascularized flaps to close the surgical site, depending on the general conditions of the patient. Esthetic and functional results are challenging to achieve for the prosthodontist, as variable amount of hard and soft tissues are removed. This report describes the fabrication of a two-piece hollow obturator for a 19-year-old patient who underwent wide surgical excision of the osteosarcoma of the maxilla and was rehabilitated to function. In this case, the surgical site was covered with submental flap, and the second piece of the obturator provided fullness to the lost malar prominence. © 2015 by the American College of Prosthodontists.

Anterior chamber gas bubble emergence pattern during femtosecond LASIK-flap creation.

PubMed

Robert, Marie-Claude; Khreim, Nour; Todani, Amit; Melki, Samir A

2015-09-01

To characterise the emergence pattern of cavitation bubbles into the anterior chamber (AC) following femtosecond laser-assisted in situ keratomileusis (LASIK)-flap creation Retrospective review of patients undergoing femtosecond LASIK surgery at Boston Laser, a private refractive surgery practice in Boston, Massachusetts, between December 2008 and February 2014. Patient charts were reviewed to identify all cases with gas bubble migration into the AC. Surgical videos were examined and the location of bubble entry was recorded separately for right and left eyes. Five thousand one hundred and fifty-eight patients underwent femtosecond LASIK surgery. Air bubble migration into the AC, presumably via the Schlemm's canal and trabecular meshwork, occurred in 1% of cases. Patients with AC bubbles had an average age of 33±8 years with a measured LASIK flap thickness of 96±21 μm. The occurrence of gas bubbles impaired iris registration in 64% of cases. Gas bubbles appeared preferentially in the nasal or inferior quadrants for right (92% of cases) and left (100% of cases) eyes. This bubble emergence pattern is significantly different from that expected with a random distribution (p<0.0001) and did not seem associated with decentration of the femtosecond laser docking system. The migration of gas bubbles into the AC is a rare occurrence during femtosecond laser flap creation. The preferential emergence of gas bubbles into the nasal and inferior quadrants of the AC may indicate a distinctive anatomy of the nasal Schlemm's canal. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.

[History of ureteropelvic junction obstruction repair (pyeloplasty). From Trendelenburg (1886) to the present].

PubMed

Poulakis, V; Witzsch, U; Schultheiss, D; Rathert, P; Becht, E

2004-12-01

The first reconstructive procedure for ureteropelvic junction (UPJ) obstruction was performed by Trendelenburg in 1886. The important milestones in the reconstruction of UPJ are discussed and all available historical papers and reports since 1886 are reviewed. Kuster published the first successful dismembered pyeloplasty 5 years later, but his technique was prone to strictures. In 1892, the application of the Heineke-Mickulicz principle by Fenger resulted in bulking and kinking with obstruction. Plication of the renal pelvis, first introduced by Israel in 1896, was modified by Kelly in 1906. After the principle of the Finney pyloroplasty, von Lichtenberg designed his pyeloplasty in 1921, best suited to cases of high implantation of the ureter. Foley modified flap techniques, first introduced by Schwyzer in 1923 after the application of the Durante pyloroplasty principle, successfully to Y-V pyeloplasty in 1937. Culp and de-Weerd introduced the spiral flap in 1951. Scardino and Prince reported about the vertical flap in 1953. Patel published the extra-long spiral flap technique in 1982. In order to decrease the likelihood of stricture, Nesbit, in 1949, modified Kuster's procedure by utilizing an elliptic anastomosis. In the same year, Anderson and Hynes, published their technique. With the advent of endourology, several minimally invasive procedures were applied: antegrade or retrograde endopyelotomy, balloon dilation, and laparoscopic pyeloplasty. The concept of full-thickness incision of the narrow segment followed by prolonged stenting was first described in 1903 by Albarran and was popularized by Davis in 1943. Several basic principles must be applied in order to ensure successful repair: the resultant anastomosis should be widely patent, performed in a watertight fashion without tension. Endopyelotomy represents an alternative to open surgery.

Pedal macrodactyly: coverage of a large defect with a rectus abdominus free flap.

PubMed

Hendrix, C L; Thomson, J G; Blume, P A

2000-01-01

The authors report a case of a unique reconstructive approach for an isolated macrodactyly of the lower extremity in an otherwise healthy African male. Surgical treatment included excision and local resection of the affected hypertrophied skin, soft tissue, and bone. A rectus abdominis free-tissue transfer and split-thickness skin graft were used for coverage of the defect. The foot healed without complication, and at 2-year follow-up, the patient had an aesthetically pleasing and fully functional result.

Advancements in adaptive aerodynamic technologies for airfoils and wings

NASA Astrophysics Data System (ADS)

Jepson, Jeffrey Keith

Although aircraft operate over a wide range of flight conditions, current fixed-geometry aircraft are optimized for only a few of these conditions. By altering the shape of the aircraft, adaptive aerodynamics can be used to increase the safety and performance of an aircraft by tailoring the aircraft for multiple flight conditions. Of the various shape adaptation concepts currently being studied, the use of multiple trailing-edge flaps along the span of a wing offers a relatively high possibility of being incorporated on aircraft in the near future. Multiple trailing-edge flaps allow for effective spanwise camber adaptation with resulting drag benefits over a large speed range and load alleviation at high-g conditions. The research presented in this dissertation focuses on the development of this concept of using trailing-edge flaps to tailor an aircraft for multiple flight conditions. One of the major tasks involved in implementing trailing-edge flaps is in designing the airfoil to incorporate the flap. The first part of this dissertation presents a design formulation that incorporates aircraft performance considerations in the inverse design of low-speed laminar-flow adaptive airfoils with trailing-edge cruise flaps. The benefit of using adaptive airfoils is that the size of the low-drag region of the drag polar can be effectively increased without increasing the maximum thickness of the airfoil. Two aircraft performance parameters are considered: level-flight maximum speed and maximum range. It is shown that the lift coefficients for the lower and upper corners of the airfoil low-drag range can be appropriately adjusted to tailor the airfoil for these two aircraft performance parameters. The design problem is posed as a part of a multidimensional Newton iteration in an existing conformal-mapping based inverse design code, PROFOIL. This formulation automatically adjusts the lift coefficients for the corners of the low-drag range for a given flap deflection as required for the airfoil-aircraft matching. Examples are presented to illustrate the flapped-airfoil design approach for a general aviation aircraft and the results are validated by comparison with results from post-design aircraft performance computations. Once the airfoil is designed to incorporate a TE flap, it is important to determine the most suitable flap angles along the wing for different flight conditions. The second part of this dissertation presents a method for determining the optimum flap angles to minimize drag based on pressures measured at select locations on the wing. Computational flow simulations using a panel method are used "in the loop" for demonstrating closed-loop control of the flaps. Examples in the paper show that the control algorithm is successful in correctly adapting the wing to achieve the target lift distributions for minimizing induced drag while adjusting the wing angle of attack for operation of the wing in the drag bucket. It is shown that the "sense-and-adapt" approach developed is capable of handling varying and unpredictable inflow conditions. Such a capability could be useful in adapting long-span flexible wings that may experience significant and unknown atmospheric inflow variations along the span. To further develop the "sense-and-adapt" approach, the method was tested experimentally in the third part of the research. The goal of the testing was to see if the same results found computationally can be obtained experimentally. The North Carolina State University subsonic wind tunnel was used for the wind tunnel tests. Results from the testing showed that the "sense-and-adapt" approach has the same performance experimentally as it did computationally. The research presented in this dissertation is a stepping stone towards further development of the concept, which includes modeling the system in the Simulink environment and flight experiments using uninhabited aerial vehicles.

Lip reposition surgery: A new call in periodontics

PubMed Central

Sheth, Tejal; Shah, Shilpi; Shah, Mihir; Shah, Ekta

2013-01-01

“Gummy smile” is a major concern for a large number of patients visiting the dentist. Esthetics has now become an integral part of periodontal treatment plan. This article presents a case of a gummy smile in which esthetic correction was achieved through periodontal plastic surgical procedure wherein a 10-12 mm of partial-thickness flap was dissected apical to mucogingival junction followed by approximation of the flaps. This novel technique gave excellent post-operative results with enormous patient satisfaction. This surgical chair-side procedure being one of its kinds with outstanding results is very rarely performed by Periodontists. Thus, a lot of clinical work and literature review with this surgical technique is required. To make it a routine surgical procedure this technique can be incorporated as a part of periodontal plastic surgery in the text. Hence, we have put forward experience of a case with critical analysis of the surgical technique including the limitations of the technique. PMID:24124310

An investigation of the application of laser-assisted indocyanine green fluorescent dye angiography in pedicle transverse rectus abdominus myocutaneous breast reconstruction.

PubMed

Newman, Martin I; Samson, Michel C; Tamburrino, Joseph F; Swartz, Kimberly A; Brunworth, Louis

2011-01-01

Pedicle transverse rectus abdominus myocutaneous (pTRAM) flaps remain the most common method of autologous tissue breast reconstruction. Using pTRAM flaps, complications often arise postoperatively, secondary to inadequate circulation. Tissues from distant angiosomes are associated with poorer perfusion, but this differs among patients. Many modalities have been used to reduce the risk of complications, but none have achieved widespread application. The authors believe that laser-assisted indocyanine green fluorescent dye angiography (LA-ICGA) can potentially reduce the risk of complications. In two routine, single-pedicle, ipsilateral pTRAM flaps, LA-ICGA imaging was performed following the division of the distal rectus muscle and deep inferior epigastric pedicle. The resulting images were used to guide design of the flap and debridement. In case 1, good perfusion was observed in zone 1 and part of zone 2. In case 2, good perfusion was observed in zone 1 and 50% of zone 3, with little perfusion in zone 2. In both cases, tissues with poor perfusion were debrided before transfer and inset. In both patients, there were no issues with wound healing, tissue necrosis or fat necrosis. The variability of perfusion of the pTRAM flap among individuals is well appreciated. LA-ICGA helped to determine the limits of good perfusion and, therefore, the limits of tissue to be preserved for transfer and inset. This helped to avoid harvesting poorly perfused tissue that would have almost certainly experienced necrosis and, ultimately, would have reduced the risk of postoperative complications.

An investigation of the application of laser-assisted indocyanine green fluorescent dye angiography in pedicle transverse rectus abdominus myocutaneous breast reconstruction

PubMed Central

Newman, Martin I; Samson, Michel C; Tamburrino, Joseph F; Swartz, Kimberly A; Brunworth, Louis

2011-01-01

BACKGROUND: Pedicle transverse rectus abdominus myocutaneous (pTRAM) flaps remain the most common method of autologous tissue breast reconstruction. Using pTRAM flaps, complications often arise postoperatively, secondary to inadequate circulation. Tissues from distant angiosomes are associated with poorer perfusion, but this differs among patients. Many modalities have been used to reduce the risk of complications, but none have achieved widespread application. The authors believe that laser-assisted indocyanine green fluorescent dye angiography (LA-ICGA) can potentially reduce the risk of complications. METHODS: In two routine, single-pedicle, ipsilateral pTRAM flaps, LA-ICGA imaging was performed following the division of the distal rectus muscle and deep inferior epigastric pedicle. The resulting images were used to guide design of the flap and debridement. RESULTS: In case 1, good perfusion was observed in zone 1 and part of zone 2. In case 2, good perfusion was observed in zone 1 and 50% of zone 3, with little perfusion in zone 2. In both cases, tissues with poor perfusion were debrided before transfer and inset. In both patients, there were no issues with wound healing, tissue necrosis or fat necrosis. CONCLUSIONS: The variability of perfusion of the pTRAM flap among individuals is well appreciated. LA-ICGA helped to determine the limits of good perfusion and, therefore, the limits of tissue to be preserved for transfer and inset. This helped to avoid harvesting poorly perfused tissue that would have almost certainly experienced necrosis and, ultimately, would have reduced the risk of postoperative complications. PMID:22379372

The Use of Split-Thickness Skin Grafts on Diabetic Foot Ulcerations: A Literature Review

PubMed Central

McCartan, Brant; Dinh, Thanh

2012-01-01

Diabetic foot ulcerations are historically difficult to treat despite advanced therapeutic modalities. There are numerous modalities described in the literature ranging from noninvasive topical wound care to more invasive surgical procedures such as primary closure, skin flaps, and skin grafting. While skin grafting provides faster time to closure with a single treatment compared to traditional topical wound treatments, the potential risks of donor site morbidity and poor wound healing unique to the diabetic state have been cited as a contraindication to its widespread use. In order to garner clarity on this issue, a literature review was undertaken on the use of split-thickness skin grafts on diabetic foot ulcers. Search of electronic databases yielded four studies that reported split-thickness skin grafts as definitive means of closure. In addition, several other studies employed split-thickness skin grafts as an adjunct to a treatment that was only partially successful or used to fill in the donor site of another plastic surgery technique. When used as the primary closure on optimized diabetic foot ulcerations, split-thickness skin grafts are 78% successful at closing 90% of the wound by eight weeks. PMID:22666573

An Effective Algorithm for Management of Noses with Thick Skin.

PubMed

Guyuron, Bahman; Lee, Michelle

2017-04-01

Thicker nasal skin blunts the definition of the underlying osseocartilaginous frame and the delicate topography of the nose posing additional challenges in producing desirable tip definition. Despite the recognized challenge in this patient population, there is a paucity of literature on how to overcome this problem. The goal of this article is to provide a systematic algorithm to manage patients with thick nasal skin. Approach to the thick nasal skin patient begins with an evaluation of the etiology of their skin thickness. Skin thickness secondary to sebaceous overactivity is diminished with the use of retinoic acid derivatives, lasers or isotretinoin (Accutane), commonly under the advice of the dermatologist. Rhinoplasty maneuvers include open technique, raising a healthy and reasonably thick skin flap overlying the tip, removing the remaining fat overlying and between the domes, creating a firm cartilaginous frame and eliminating dead space using the supratip suture reported by the senior author, and trimming redundant nasal skin envelope when indicated. This systematic approach has been greatly effective in achieving often predictable and aesthetically pleasing rhinoplasty results. This journal requires that authors assign a level of evidence to each article. For a full description of these evidence-based medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Flap-lag-torsional dynamic modelling of rotor blades in hover and in forward flight, including the effect of cubic nonlinearities

NASA Technical Reports Server (NTRS)

Crespodasilva, M. R. M.

1981-01-01

The differential equations of motion, and boundary conditions, describing the flap-lead/lag-torsional motion of a flexible rotor blade with a precone angle and a variable pitch angle, which incorporates a pretwist, are derived via Hamilton's principle. The meaning of inextensionality is discussed. The equations are reduced to a set of three integro partial differential equations by elimination of the extension variable. The generalized aerodynamic forces are modelled using Greenberg's extension of Theodorsen's strip theory. The equations of motion are systematically expanded into polynomial nonlinearities with the objective of retaining all terms up to third degree. The blade is modeled as a long, slender, of isotropic Hookean materials. Offsets from the blade's elastic axis through its shear center and the axes for the mass, area and aerodynamic centers, radial nonuniformaties of the blade's stiffnesses and cross section properties are considered and the effect of warp of the cross section is included in the formulation.

Variability and reliability of the vastus lateralis muscle anatomy.

PubMed

D'Arpa, Salvatore; Toia, Francesca; Brenner, Erich; Melloni, Carlo; Moschella, Francesco; Cordova, Adriana

2016-08-01

The aims of this study are to investigate the variability of the morphological and neurovascular anatomy of the vastus lateralis (VL) muscle and to describe the relationships among its intramuscular partitions and with the other muscles of the quadriceps femoris. Clinical implications in its reliability as a flap donor are also discussed. In 2012, the extra- and intramuscular neurovascular anatomy of the VL was investigated in 10 cadaveric lower limbs. In three specimens, the segmental arterial pedicles were injected with latex of different colors to point out their anastomotic connections. The morphological anatomy was investigated with regard to the mutual relationship of the three muscular partitions and the relation of the VL with the other muscles of the quadriceps femoris. The VL has a segmental morphological anatomy. However, the fibers of its three partitions interconnect individually and with the other bellies of the quadriceps femoris, particularly, in several variable portions with the vastus intermedius and mainly in the posterior part of the VL. The lateral circumflex femoral artery and its branches have variable origin, but demonstrate constant segmental distribution. Intramuscular dissection and colored latex injections show a rich anastomotic vascular network among the three partitions. Moderate variability exists in both the myological and the neurovascular anatomy of the VL. Despite this variability, the anatomy of the VL always has a constant segmental pattern, which makes the VL a reliable flap donor. Detailed knowledge of the VL anatomy could have useful applications in a broad clinical field.

Free-style puzzle flap: the concept of recycling a perforator flap.

PubMed

Feng, Kuan-Ming; Hsieh, Ching-Hua; Jeng, Seng-Feng

2013-02-01

Theoretically, a flap can be supplied by any perforator based on the angiosome theory. In this study, the technique of free-style perforator flap dissection was used to harvest a pedicled or free skin flap from a previous free flap for a second difficult reconstruction. The authors call this a free-style puzzle flap. For the past 3 years, the authors treated 13 patients in whom 12 pedicled free-style puzzle flaps were harvested from previous redundant free flaps and recycled to reconstruct soft-tissue defects at various anatomical locations. One free-style free puzzle flap was harvested from a previous anterolateral thigh flap for buccal cancer to reconstruct a foot defect. Total flap survival was attained in 12 of 13 flaps. One transferred flap failed completely. This patient had received postoperative radiotherapy after the initial cancer ablation and free anterolateral thigh flap reconstruction. Another free flap was used to close and reconstruct the wound. All the donor sites could be closed primarily. The free-style puzzle flap, harvested from a previous redundant free flap and used as a perforator flap to reconstruct a new defect, has proven to be versatile and reliable. When indicated, it is an alternative donor site for further reconstruction of soft-tissue defects.

Newly Designed Upper Lateral Cartilage Flap for Preventing Depression of the Keystone Area in Large-Nose Septorhinoplasty.

PubMed

Sharafi, Maryam; Jalessi, Maryam; Adamson, Peter A

2015-01-01

Because large dorsal reduction may weaken the keystone area, later notching of this area should be prevented while reducing large humps during septorhinoplasty. To determine whether a triangular-shaped flap of upper lateral cartilages (ULCs) that we designed can prevent secondary deformity of the nasal dorsum in the keystone area following large hump reduction. In this retrospective study, medical records as well as preoperative and postoperative photographs of septorhinoplasty cases in which triangular flaps had been used between April 1, 2012, and March 3, 2013, were reviewed. Data analysis was conducted from March 3 to May 10, 2014. Demographic data, amount of hump reduction, and any irregularity of the dorsum in the keystone area mentioned in the medical record or identified in postoperative profile view photographs were assessed. The study was conducted in a research center, and the operations were performed in a private setting. Patients had been scheduled for septorhinoplasty with flap reconstruction if more than 3 mm of dorsal hump reduction was planned and their skin was not thin. Of 41 identified patients, 3 could not be monitored for 1 year; 38 patients were included in the analysis. Open septorhinoplasty had been performed, and more than 3 mm of dorsum had been removed in all patients whose data were analyzed. During stepwise resection of the nasal dorsum, a triangular-shaped remnant of the most cephalomedial part of the ULC was maintained intact on each side over the keystone area. Irregularity of the nasal dorsum over the keystone area in postoperative profile view photographs. More than 3 mm of hump reduction had been made in all 38 patients. No irregularities were observed in the postoperative photographs or had been found on digital examination of the keystone area after at least 12 months of follow-up. Maintaining a remnant of the ULC over the keystone area in the form of a triangular-shaped flap on each side is a simple, reliable, and durable way to prevent notching of the keystone area during lowering of the nasal dorsum in large noses with sufficient skin thickness. 4.

A prospective, contralateral eye study comparing thin-flap LASIK (sub-Bowman keratomileusis) with photorefractive keratectomy.

PubMed

Slade, Stephen G; Durrie, Daniel S; Binder, Perry S

2009-06-01

To determine the differences in the visual results, pain response, biomechanical effect, quality of vision, and higher-order aberrations, among other parameters, in eyes undergoing either photorefractive keratectomy (PRK) or thin-flap LASIK/sub-Bowman keratomileusis (SBK; intended flap thickness of +/-100 microm and 8.5-mm diameter) at 1, 3, and 6 months after surgery. A contralateral eye pilot study. Fifty patients (100 eyes) were enrolled at 2 sites. The mean preoperative spherical refraction was -3.66 diopters (D) and the mean cylinder was -0.66 D for all eyes. Eyes in the PRK group underwent 8.5-mm ethanol-assisted PRK, whereas in eyes in the SBK group, an 8.5-mm, (intended) 100-microm flap was created with a 60-kHz IntraLase femtosecond laser (Advanced Medical Optics, Santa Ana, CA). All eyes underwent a customized laser ablation using an Alcon LADARVision 4000 CustomCornea excimer laser (Alcon Laboratories, Fort Worth, TX). Preoperative and postoperative tests included best spectacle-corrected visual acuity, uncorrected visual acuity (UCVA), corneal topography, wavefront aberrometry, retinal image quality, and contrast sensitivity. Patients completed subjective questionnaires at each visit. One- and 3-month UCVA results showed a statistically significant difference: SBK, 88% 20/20 or better vs. 48% 20/20 or better for PRK. At 6 months, UCVA was 94% 20/20 or better for PRK and 92% for SBK. At 1 and 3 months, the SBK group had lower higher-order aberrations (coma and spherical aberration; P

Ultrasonic biomicroscopy in ophthalmology and eye banking

NASA Astrophysics Data System (ADS)

Rosenwasser, George O. D.

1999-06-01

Echography has become a valuable diagnostic tool in ophthalmology. Ultrasonic biomicroscopy (UBM) in particular may be applied to the evaluation of small lesions of the anterior segment of the eye. Disease processes such as conjunctival and iris melanoma, other forms of neoplasia, intraocular cysts, narrow angle glaucoma, and intraocular foreign bodies can be diagnostically evaluated and followed longitudinally by UBM. Combining UBM with spectroscopy may become useful in determining cell type origins of a variety of tumors. Eye banking also has an increased need for UBM in corneal tissue banking. The recent development of the Laser In Situ Keratomileusis procedure has allowed corneal surgeries to create a partial thickness flap of tissue in the cornea, remove tissue from the base of the cornea with excimer laser ablation, and replace the hinged flap. This causes a substantial change in refractive error while thinning the cornea and leaving an interface within the corneal stroma. The ability to detect this type of surgery is essential in eye banking. Ultrasonic pachymetry to determine central thickness and biomicroscopy to detect the presence of an interface are essential in avoiding the use of these corneas for transplantation purposes. Determining the topography of the preserved corneas is another potential application for ultrasonography. Using this information to reduce optical aberration after transplant is crucial in improving visual performance post transplantation. A review of the anatomy of the eye, pathology of ocular diseases relevant to UBM, and principles of eye banking will be presented.

Venous Graft for Full-thickness Palpebral Reconstruction

PubMed Central

Sanna, Marco Pietro Giuseppe; Maxia, Sara; Esposito, Salvatore; Di Giulio, Stefano; Sartore, Leonardo

2015-01-01

Summary: Full-thickness palpebral reconstruction is a challenge for most surgeons. The complex structures composing the eyelid must be reconstructed with care both for functional and cosmetic reasons. It is possible to find in literature different methods to reconstruct either the anterior or posterior lamella, based on graft or flaps. Most patients involved in this kind of surgery are elderly. It is important to use easy and fast procedures to minimize the length of the operation and its complications. In our department, we used to reconstruct the anterior lamella by means of a Tenzel or a Mustardé flap, whereas for the posterior lamella, we previously utilized a chondromucosal graft, harvested from nasal septum. Thus, these procedures required general anesthesia and long operatory time. We started using a vein graft for the posterior lamella. In this article, we present a series of 9 patients who underwent complex palpebral reconstruction for oncological reasons. In 5 patients (group A), we reconstructed the tarsoconjunctival layer by a chondromucosal graft, whereas in 4 patients (group B), we used a propulsive vein graft. The follow-up was from 10 to 20 months. The patient satisfaction was high, and we had no relapse in the series. In group A, we had more complications, including ectropion and septal perforations, whereas in group B, the operation was faster and we noted minor complications. In conclusion, the use of a propulsive vein to reconstruct the tarsoconjunctival layer was a reliable, safe, and fast procedure that can be considered in complex palpebral reconstructions. PMID:26034651

Vermillion Reconstruction With Anal Verge Transitional Epithelium: Turning Things Upside Down.

PubMed

Levi, Benjamin; Ricci, Joseph A; Donelan, Matthias B

2018-02-20

Postburn lip deformities pose a significant set of challenges to reconstructive burn surgeons because of the complex anatomy, diverse functions, and specialized nature of the lip tissues. There has been a paucity of literature on restoration of the vermillion to date. The authors report on two patients who suffered burn injuries resulting in significant lip deformities who underwent a novel method of vermillion reconstruction with a full thickness anal verge skin graft. Both patients tolerated the procedure well without complications. One patient had slight hyperpigmentation of the graft which was treated with a phenol peel to cause intentional lightening. Overall, both patients had a restored vermillion border and improved color match and contour of the lip. Histologic analysis of the anal verge demonstrates that it has a nonkeratinized, transitional epithelial architecture which is nearly identical to that of the vermillion tissue. Skin grafting remains one of the cornerstones of tissue replacement in acute burn care and burn reconstruction. The vermillion represents an area of specialized tissue that is not well reconstructed with simple skin grafts. Other methods for reconstruction involve lip switch operations or local flaps, like a ventral tongue flap. These procedures are not without limitation and can often cause microstomia among other issues. With no donor site morbidity, a full thickness anal verge skin graft represents the closest approximation of actual vermillion tissue found anywhere else in the body and should be considered a viable option in the reconstruction of these challenging patients.

"Reading man flap" design for reconstruction of circular infraorbital and malar skin defects.

PubMed

Seyhan, Tamer; Caglar, Baris

2008-11-01

Surgical complications such as lid retraction and ectropion from graft or flap scar contracture make reconstruction of skin defects in the malar and infraorbital regions challenging. A new flap design, the reading man flap, was used to overcome these problems. The Limberg and bilobed flap were compared with the reading man flap. The reading man flap consists mainly of a superiorly based quadrangular flap and an inferiorly based triangular flap. Malar and infraorbital circular skin defects measuring 14 x 14 to 40 x 40 mm were reconstructed with a reading man flap in 13 patients. The defects occurred after basal cell carcinoma in all patients. The Limberg flap, bilobed flap, and reading man flap were planned for same-sized defects on the abdominoplasty resection material. The results were compared in terms of total scar area, scar length, and total healthy skin area discarded. When comparing the 3 flap designs, the reading man flap was the most suitable flap in terms of total scar area and length. The reading man flap can be used to reconstruct malar and infraorbital circular defects with good cosmetic results and without creating any tractional forces to the eyelids.

Topology optimization of pressure adaptive honeycomb for a morphing flap

NASA Astrophysics Data System (ADS)

Vos, Roelof; Scheepstra, Jan; Barrett, Ron

2011-03-01

The paper begins with a brief historical overview of pressure adaptive materials and structures. By examining avian anatomy, it is seen that pressure-adaptive structures have been used successfully in the Natural world to hold structural positions for extended periods of time and yet allow for dynamic shape changes from one flight state to the next. More modern pneumatic actuators, including FAA certified autopilot servoactuators are frequently used by aircraft around the world. Pneumatic artificial muscles (PAM) show good promise as aircraft actuators, but follow the traditional model of load concentration and distribution commonly found in aircraft. A new system is proposed which leaves distributed loads distributed and manipulates structures through a distributed actuator. By using Pressure Adaptive Honeycomb (PAH), it is shown that large structural deformations in excess of 50% strains can be achieved while maintaining full structural integrity and enabling secondary flight control mechanisms like flaps. The successful implementation of pressure-adaptive honeycomb in the trailing edge of a wing section sparked the motivation for subsequent research into the optimal topology of the pressure adaptive honeycomb within the trailing edge of a morphing flap. As an input for the optimization two known shapes are required: a desired shape in cruise configuration and a desired shape in landing configuration. In addition, the boundary conditions and load cases (including aerodynamic loads and internal pressure loads) should be specified for each condition. Finally, a set of six design variables is specified relating to the honeycomb and upper skin topology of the morphing flap. A finite-element model of the pressure-adaptive honeycomb structure is developed specifically tailored to generate fast but reliable results for a given combination of external loading, input variables, and boundary conditions. Based on two bench tests it is shown that this model correlates well to experimental results. The optimization process finds the skin and honeycomb topology that minimizes the error between the acquired shape and the desired shape in each configuration.

Four-flap Breast Reconstruction: Bilateral Stacked DIEP and PAP Flaps

PubMed Central

Mayo, James L.; Allen, Robert J.

2015-01-01

Background: In cases of bilateral breast reconstruction when the deep inferior epigastric perforator (DIEP) free flap alone does not provide sufficient volume for body-specific reconstruction, stacking each DIEP flap with a second free flap will deliver added volume and maintain a purely autologous reconstruction. Stacking the profunda artery perforator (PAP) flap with the DIEP flap offers favorable aesthetics and ideal operative efficiency. We present the indications, technique, and outcomes of our experience with 4-flap breast reconstruction using stacked DIEP/PAP flaps. Methods: The authors performed 4-flap DIEP/PAP breast reconstruction in 20 patients who required bilateral reconstruction without adequate single donor flap volume. The timing of reconstruction, average mastectomy/flap weights, and operative time are reported. Complications reviewed include fat necrosis, dehiscence, hematoma, seroma, mastectomy flap necrosis, and flap loss. Results: Twenty patients underwent 4-flap DIEP/PAP breast reconstruction. Surgical time averaged 7 hours and 20 minutes. The primary recipient vessels were the antegrade and retrograde internal mammary vessels. No flap losses occurred. Complications included 1 hematoma, 1 incidence of arterial and venous thrombosis successfully treated with anastomotic revision, 1 incidence of thigh donor site dehiscence, and 3 episodes of minor mastectomy skin flap necrosis. Conclusions: Four-flap breast reconstruction is a favorable autologous reconstructive option for patients requiring bilateral reconstruction without adequate single donor flap volume. Stacking DIEP/PAP flaps as described is both safe and efficient. Furthermore, this combination provides superior aesthetics mirroring the natural geometry of the breast. Bilateral stacked DIEP/PAP flaps represent our first choice for breast reconstruction in this patient population. PMID:26090273

Free Boomerang-shaped Extended Rectus Abdominis Myocutaneous flap: The longest possible skin/myocutaneous free flap for soft tissue reconstruction of extremities.

PubMed

Koul, Ashok R; Nahar, Sushil; Prabhu, Jagdish; Kale, Subhash M; Kumar, Praveen H P

2011-09-01

A soft tissue defect requiring flap cover which is longer than that provided by the conventional "long" free flaps like latissimus dorsi (LD) and anterolateral thigh (ALT) flap is a challenging problem. Often, in such a situation, a combination of flaps is required. Over the last 3 years, we have managed nine such defects successfully with a free "Boomerang-shaped" Extended Rectus Abdominis Myocutaneous (BERAM) flap. This flap is the slightly modified and "free" version of a similar flap described by Ian Taylor in 1983. This is a retrospective study of patients who underwent free BERAM flap reconstruction of soft tissue defects of extremity over the last 3 years. We also did a clinical study on 30 volunteers to compare the length of flap available using our design of BERAM flap with the maximum available flap length of LD and ALT flaps, using standard markings. Our clinical experience of nine cases combined with the results of our clinical study has confirmed that our design of BERAM flap consistently provides a flap length which is 32.6% longer than the standard LD flap and 42.2% longer than the standard ALT flap in adults. The difference is even more marked in children. The BERAM flap is consistently reliable as long as the distal end is not extended beyond the mid-axillary line. BERAM flap is simple in design, easy to harvest, reliable and provides the longest possible free skin/myocutaneous flap in the body. It is a useful new alternative for covering long soft tissue defects in the limbs.

A Novel Augmented Reality-Based Navigation System in Perforator Flap Transplantation - A Feasibility Study.

PubMed

Jiang, Taoran; Zhu, Ming; Zan, Tao; Gu, Bin; Li, Qingfeng

2017-08-01

In perforator flap transplantation, dissection of the perforator is an important but difficult procedure because of the high variability in vascular anatomy. Preoperative imaging techniques could provide substantial information about vascular anatomy; however, it cannot provide direct guidance for surgeons during the operation. In this study, a navigation system (NS) was established to overlie a vascular map on surgical sites to further provide a direct guide for perforator flap transplantation. The NS was established based on computed tomographic angiography and augmented reality techniques. A virtual vascular map was reconstructed according to computed tomographic angiography data and projected onto real patient images using ARToolKit software. Additionally, a screw-fixation marker holder was created to facilitate registration. With the use of a tracking and display system, we conducted the NS on an animal model and measured the system error on a rapid prototyping model. The NS assistance allowed for correct identification, as well as a safe and precise dissection of the perforator. The mean value of the system error was determined to be 3.474 ± 1.546 mm. Augmented reality-based NS can provide precise navigation information by directly displaying a 3-dimensional individual anatomical virtual model onto the operative field in real time. It will allow rapid identification and safe dissection of a perforator in free flap transplantation surgery.

Treatment of Wound Healing Disorders of Radial Forearm Free Flap Donor Sites Using Cold Atmospheric Plasma: A Proof of Concept.

PubMed

Hartwig, Stefan; Doll, Christian; Voss, Jan Oliver; Hertel, Moritz; Preissner, Saskia; Raguse, Jan Dirk

2017-02-01

The treatment of wound healing disturbances of the radial forearm free flap donor site after reconstructive surgery is typically long and burdensome and often requires additional surgery. Cold atmospheric plasma is a promising approach to overcome these impairments. The aim of this proof of concept study was to evaluate the clinical outcome of plasma irradiation in patients with wound healing disorders with exposed brachial tendons of the radial forearm. Four patients (mean age 64.2 years, range 44 to 80) who had undergone radial forearm free flap procedures and developed wound healing disturbance leading to exposed flexor tendons were included in the present prospective case series. In addition to routine wound care, all sites were irradiated with cold atmospheric plasma. The primary outcome variable was complete wound closure. In all patients, complete wound repair in terms of the absence of tendon exposure was observed within a mean treatment time of 10.1 weeks (range 4.9 to 16). No undesirable side effects were observed, and no inflammation or infection occurred. Cold atmospheric plasma could offer a reliable conservative treatment option for complicated wound healing disturbances. This was exemplarily shown in the case of radial forearm free flap donor site morbidity with exposed flexor tendons in the present study. Copyright © 2016 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Free Boomerang-shaped Extended Rectus Abdominis Myocutaneous flap: The longest possible skin/myocutaneous free flap for soft tissue reconstruction of extremities

PubMed Central

Koul, Ashok R.; Nahar, Sushil; Prabhu, Jagdish; Kale, Subhash M.; Kumar, Praveen H. P.

2011-01-01

Background: A soft tissue defect requiring flap cover which is longer than that provided by the conventional “long” free flaps like latissimus dorsi (LD) and anterolateral thigh (ALT) flap is a challenging problem. Often, in such a situation, a combination of flaps is required. Over the last 3 years, we have managed nine such defects successfully with a free “Boomerang-shaped” Extended Rectus Abdominis Myocutaneous (BERAM) flap. This flap is the slightly modified and “free” version of a similar flap described by Ian Taylor in 1983. Materials and Methods: This is a retrospective study of patients who underwent free BERAM flap reconstruction of soft tissue defects of extremity over the last 3 years. We also did a clinical study on 30 volunteers to compare the length of flap available using our design of BERAM flap with the maximum available flap length of LD and ALT flaps, using standard markings. Results: Our clinical experience of nine cases combined with the results of our clinical study has confirmed that our design of BERAM flap consistently provides a flap length which is 32.6% longer than the standard LD flap and 42.2% longer than the standard ALT flap in adults. The difference is even more marked in children. The BERAM flap is consistently reliable as long as the distal end is not extended beyond the mid-axillary line. Conclusion: BERAM flap is simple in design, easy to harvest, reliable and provides the longest possible free skin/myocutaneous flap in the body. It is a useful new alternative for covering long soft tissue defects in the limbs. PMID:22279271

The possibility for use of venous flaps in plastic surgery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Baytinger, V. F., E-mail: baitinger@mail.tomsknet.ru; Kurochkina, O. S., E-mail: kurochkinaos@yandex.ru; Selianinov, K. V.

2015-11-17

The use of venous flaps is controversial. The mechanism of perfusion of venous flaps is still not fully understood. The research was conducted on 56 white rats. In our experimental work we studied two different models of venous flaps: pedicled venous flap (PVF) and pedicled arterialized venous flap (PAVF). Our results showed that postoperative congestion was present in all flaps. However 66.7% of all pedicled venous flaps and 100% of all pedicled arterialized venous flaps eventually survived. Histological examination revealed that postoperatively the blood flow in the skin of the pedicled arterialized venous flap became «re-reversed» again; there were nomore » differences between mechanism of survival of venous flaps and other flaps. On the 7-14th day in the skin of all flaps were processes of neoangiogenesis and proliferation. Hence the best scenario for the clinical use of venous flaps unfolds when both revascularization and skin coverage are required.« less

Routine preoperative colour Doppler duplex ultrasound scanning in anterolateral thigh flaps.

PubMed

Lichte, Johanna; Teichmann, Jan; Loberg, Christina; Kloss-Brandstätter, Anita; Bartella, Alexander; Steiner, Timm; Modabber, Ali; Hölzle, Frank; Lethaus, Bernd

2016-10-01

The anterolateral thigh flap (ALT) is often used to reconstruct the head and neck and depends on one or more skin perforators, which often present with variable anatomy. The aim of this study was to localise and evaluate the precise position of these perforators preoperatively with colour Doppler duplex ultrasound scanning (US). We detected 74 perforators in 30 patients. The mean duration of examination with colour Doppler was 29 (range 13-51) minutes. Adequate perforators and their anatomical course could be detected preoperatively extremely accurately (p<0.001). The mean difference between the preoperatively marked, and the real, positions was 6.3 (range 0-16) mm. There was a highly significant correlation between the accuracy of the prediction and the body mass index of the patient (0.75; p<0.001). Neither the age nor the sex of the patient correlated with the accuracy of the prediction. Colour Doppler duplex US used preoperatively to localise perforators in ALT flaps is reliable and could be adopted as standard procedure. Copyright © 2016 The British Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.

Computation of spanwise distribution of circulation and lift coefficient for flapped wings of arbitrary planform

NASA Technical Reports Server (NTRS)

Razak, K.

1980-01-01

The question of the effect of distribution and magnitude of spanwise circulation and shed vorticity from an airplane wing on the distribution pattern of agricultural products distributed from an airplane was studied. The first step in an analysis of this question is the determination of the actual distribution of lift along an airplane wing, from which the pattern of shed vorticity can be determined. A procedure is developed to calculate the span loading for flapped and unflapped wings of arbitrary aspect ratio and taper ratio. The procedure was programmed on a small programmable calculator, the Hewlett Packard HP-97, and also was programmed in BASIC language. They could be used to explore the variations in span loading that can be secured by variable flap deflections or the effect of flying at varying air speeds at different airplane gross weights. Either an absolute evaluation of span loading can be secured or comparative span loading can be evaluated to determine their effect on swath width and swath distribution pattern. The programs are intended to assist the user in evaluating the effect of a given spanload distribution.

A retrospective study: Multivariate logistic regression analysis of the outcomes after pressure sores reconstruction with fasciocutaneous, myocutaneous, and perforator flaps.

PubMed

Chiu, Yu-Jen; Liao, Wen-Chieh; Wang, Tien-Hsiang; Shih, Yu-Chung; Ma, Hsu; Lin, Chih-Hsun; Wu, Szu-Hsien; Perng, Cherng-Kang

2017-08-01

Despite significant advances in medical care and surgical techniques, pressure sore reconstruction is still prone to elevated rates of complication and recurrence. We conducted a retrospective study to investigate not only complication and recurrence rates following pressure sore reconstruction but also preoperative risk stratification. This study included 181 ulcers underwent flap operations between January 2002 and December 2013 were included in the study. We performed a multivariable logistic regression model, which offers a regression-based method accounting for the within-patient correlation of the success or failure of each flap. The overall complication and recurrence rates for all flaps were 46.4% and 16.0%, respectively, with a mean follow-up period of 55.4 ± 38.0 months. No statistically significant differences of complication and recurrence rates were observed among three different reconstruction methods. In subsequent analysis, albumin ≤3.0 g/dl and paraplegia were significantly associated with higher postoperative complication. The anatomic factor, ischial wound location, significantly trended toward the development of ulcer recurrence. In the fasciocutaneous group, paraplegia had significant correlation to higher complication and recurrence rates. In the musculocutaneous flap group, variables had no significant correlation to complication and recurrence rates. In the free-style perforator group, ischial wound location and malnourished status correlated with significantly higher complication rates; ischial wound location also correlated with significantly higher recurrence rate. Ultimately, our review of a noteworthy cohort with lengthy follow-up helped identify and confirm certain risk factors that can facilitate a more informed and thoughtful pre- and postoperative decision-making process for patients with pressure ulcers. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

14 CFR 25.777 - Cockpit controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

.... Controls of a variable nature using a rotary motion must move clockwise from the off position, through an... harness (if provided) fastened. (d) Identical powerplant controls for each engine must be located to prevent confusion as to the engines they control. (e) Wing flap controls and other auxiliary lift device...

An Investigation of Wing and Aileron Loads Due to Deflected Inboard and Outboard Ailerons on a 4-Percent-Thick 30 deg Sweptback Wing at Transonic Speeds

NASA Technical Reports Server (NTRS)

Whitcomb, Charles F.; Critzos, Chris C.; Brown, Philippa F.

1961-01-01

An investigation has been conducted in the Langley 16-foot transonic tunnel to determine the changes in wing loading characteristics due to deflections of a plain faired flap-type inboard aileron, a plain faired flap-type outboard aileron, and a slab-sided thickened trailing edge outboard aileron. The test wing was 4 percent thick and had 30 sweep of the quarter chord, an aspect ratio of 3.0, a taper ratio of 0.2, and NACA 65A004 airfoil sections. The loading characteristics of the deflected ailerons were also investigated. The model was a sting-mounted wing-body combination, and pressure measurements over one wing panel (exposed area) and the ailerons were obtained for angles of attack from 0 to 20 at deflections up to +/- 15 deg for Mach numbers between 0.80 and 1.03. The test Reynolds number based on the wing mean aerodynamic chord was about 7.4 x 10(exp 6). The results of the investigation indicated that positive deflection of the plain faired flap-type inboard aileron caused significant added loading over the wing sections outboard of the aileron at all Mach numbers for model angles of attack from 0 deg or 4 deg up to 12 deg. Positive deflection of the two outboard ailerons (plain faired and slab sided with thickened trailing edge) caused significant added loading over the wing sections inboard of the ailerons for different model angle-of-attack ranges at the several test Mach numbers. The loading shapes over the ailerons were irregular and would be difficult to predict from theoretical considerations in the transonic speed range. The longitudinal and lateral center-of-pressure locations for the ailerons varied only slightly with increasing angle of attack and/or Mach number. Generally, the negative slopes of the variations of aileron hinge-moment coefficient with aileron deflection for all three ailerons varied similarly with Mach number at the test angles of attack.

NASA Innovation Fund 2010 Project Elastically Shaped Future Air Vehicle Concept

NASA Technical Reports Server (NTRS)

Nguyen, Nhan

2010-01-01

This report describes a study conducted in 2010 under the NASA Innovation Fund Award to develop innovative future air vehicle concepts. Aerodynamic optimization was performed to produce three different aircraft configuration concepts for low drag, namely drooped wing, inflected wing, and squashed fuselage. A novel wing shaping control concept is introduced. This concept describes a new capability of actively controlling wing shape in-flight to minimize drag. In addition, a novel flight control effector concept is developed to enable wing shaping control. This concept is called a variable camber continuous trailing edge flap that can reduce drag by as much as 50% over a conventional flap. In totality, the potential benefits of fuel savings offered by these concepts can be significant.

Experimental Study of Wake / Flap Interaction Noise and the Reduction of Flap Side Edge Noise

NASA Technical Reports Server (NTRS)

Hutcheson, Florence V.; Stead, Daniel J.; Plassman, Gerald E.

2016-01-01

The effects of the interaction of a wake with a half-span flap on radiated noise are examined. The incident wake is generated by bars of various widths and lengths or by a simplified landing gear model. Single microphone and phased array measurements are used to isolate the effects of the wake interaction on the noise radiating from the flap side edge and flap cove regions. The effects on noise of the wake generator's geometry and relative placement with respect to the flap are assessed. Placement of the wake generators upstream of the flap side edge is shown to lead to the reduction of flap side edge noise by introducing a velocity deficit and likely altering the instabilities in the flap side edge vortex system. Significant reduction in flap side edge noise is achieved with a bar positioned directly upstream of the flap side edge. The noise reduction benefit is seen to improve with increased bar width, length and proximity to the flap edge. Positioning of the landing gear model upstream of the flap side edge also leads to decreased flap side edge noise. In addition, flap cove noise levels are significantly lower than when the landing gear is positioned upstream of the flap mid-span. The impact of the local flow velocity on the noise radiating directly from the landing gear is discussed. The effects of the landing gear side-braces on flap side edge, flap cove and landing gear noise are shown.

The Differential Use of Bilobed and Trilobed Transposition Flaps in Cutaneous Nasal Reconstructive Surgery.

PubMed

Knackstedt, Thomas; Lee, Kachiu; Jellinek, Nathaniel J

2018-05-22

Bilobed and trilobed transposition flaps are versatile random pattern transposition flaps which reliably restore nasal symmetry, topography, light reflex, contour and are frequently used in cutaneous nasal reconstructive surgery. We wish to compare the characteristics of bilobed and trilobed flaps in cutaneous reconstructive surgery and to identify scenarios for their differential use. A retrospective chart review over 7 years of consecutive patients reconstructed with a bilobed or trilobed flap after Mohs micrographic surgery was performed. Statistical analysis of patient and surgery characteristics, anatomic distribution, postprocedural events and need for revisions after both flap types was conducted. One hundred eleven patients with bilobed flaps and 74 patients with trilobed flaps were identified. Bilobed flaps are significantly more frequently used on the inferior nasal dorsum and on the sidewall whereas trilobed flaps are significantly more frequently used on the nasal tip and infratip. No significant difference in postprocedural events (complications, erythema, trapdoor, etc) was noted between the two flap types. Bilobed and trilobed transposition flaps are versatile repairs for nasal reconstruction. Trilobed flaps may be used to repair defects in a more distal nasal location than bilobed flaps. Regardless of flap type, complications are rare.

Feasibility of Human Skin Grafts on an Isolated But Accessible Vascular Supply on Athymic Rats as a System to Study Percutaneous Penetration and Cutaneous Injury.

DTIC Science & Technology

1986-04-01

Ai87 466 FEASIBILITY OF HUMAN SKIN GRAFTS ON AN ISOLATED BUT / ACCESSIBLE VASCULAR 5 (U) UTAH UNIV SALT LAKE CITY SCHOOL OF MEDICINE 6 G KRUEGER APR...GOVT ACCESSION NO . RrCIPIcNTrS CATALOG NUMIER Feasibility of Human Skin Grafts on an Isolated 9 but Accessible Vascular Supply on Athymic Rats as...of the Skin Sandwich Flap....... . . . . . . . 35 Figure 15. Photograph of Hair Growth in a Human Split-Thickness Skin Graft on a Nude Rat

High-Lift Systems on Commercial Subsonic Airliners

NASA Technical Reports Server (NTRS)

Rudolph, Peter K. C.

1996-01-01

The early breed of slow commercial airliners did not require high-lift systems because their wing loadings were low and their speed ratios between cruise and low speed (takeoff and landing) were about 2:1. However, even in those days the benefit of high-lift devices was recognized. Simple trailing-edge flaps were in use, not so much to reduce landing speeds, but to provide better glide-slope control without sideslipping the airplane and to improve pilot vision over the nose by reducing attitude during low-speed flight. As commercial-airplane cruise speeds increased with the development of more powerful engines, wing loadings increased and a real need for high-lift devices emerged to keep takeoff and landing speeds within reasonable limits. The high-lift devices of that era were generally trailing-edge flaps. When jet engines matured sufficiently in military service and were introduced commercially, airplane speed capability had to be increased to best take advantage of jet engine characteristics. This speed increase was accomplished by introducing the wing sweep and by further increasing wing loading. Whereas increased wing loading called for higher lift coefficients at low speeds, wing sweep actually decreased wing lift at low speeds. Takeoff and landing speeds increased on early jet airplanes, and, as a consequence, runways worldwide had to be lengthened. There are economical limits to the length of runways; there are safety limits to takeoff and landing speeds; and there are speed limits for tires. So, in order to hold takeoff and landing speeds within reasonable limits, more powerful high-lift devices were required. Wing trailing-edge devices evolved from plain flaps to Fowler flaps with single, double, and even triple slots. Wing leading edges evolved from fixed leading edges to a simple Krueger flap, and from fixed, slotted leading edges to two- and three-position slats and variable-camber (VC) Krueger flaps. The complexity of high-lift systems probably peaked on the Boeing 747, which has a VC Krueger flap and triple-slotted, inboard and outboard trailing-edge flaps. Since then, the tendency in high-lift system development has been to achieve high levels of lift with simpler devices in order to reduce fleet acquisition and maintenance costs. The intent of this paper is to: (1) review available high-lift devices, their functions, and design criteria; (2) appraise high-lift systems presently in service on commercial air liners; (3) present personal study results on high-lift systems; (4) develop a weight and cost model for high-lift systems; and (5) discuss the development tendencies of future high-lift systems.

Vascularized osseous flaps and assessing their bipartate perfusion pattern via intraoperative fluorescence angiography.

PubMed

Valerio, Ian; Green, J Marshall; Sacks, Justin M; Thomas, Shane; Sabino, Jennifer; Acarturk, T Oguz

2015-01-01

Large segmental bone and composite tissue defects often require vascularized osseous flaps for definitive reconstruction. However, failed osseous flaps due to inadequate perfusion can lead to significant morbidity. Utilization of indocyanine green (ICG) fluorescence angiography has been previously shown to reliably assess soft tissue perfusion. Our group will outline the application of this useful intraoperative tool in evaluating the perfusion of vascularized osseous flaps. A retrospective review was performed to identify those osseous and/or osteocutaneous bone flaps, where ICG angiography was employed. Data analyzed included flap types, success and failure rates, and perfusion-related complications. All osseous flaps were evaluated by ICG angiography to confirm periosteal and endosteal perfusion. Overall 16 osseous free flaps utilizing intraoperative ICG angiography to assess vascularized osseous constructs were performed over a 3-year period. The flaps consisted of the following: nine osteocutaneous fibulas, two osseous-only fibulas, two scapular/parascapular with scapula bone, two quadricep-based muscle flaps, containing a vascularized femoral bone component, and one osteocutaneous fibula revision. All flap reconstructions were successful with the only perfusion-related complication being a case of delayed partial skin flap loss. Intraoperative fluorescence angiography is a useful adjunctive tool that can aid in flap design through angiosome mapping and can also assess flap perfusion, vascular pedicle flow, tissue perfusion before flap harvest, and flap perfusion after flap inset. Our group has successfully extended the application of this intraoperative tool to assess vascularized osseous flaps in an effort to reduce adverse outcomes related to preventable perfusion-related complications. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

[APPLICATION VALUE OF INDOCYANINE GREEN ANGIOGRAPHY IN FLAP RECONSTRUCTIVE SURGERY].

PubMed

Yang, Kai; Mu, Lan; Liu, Yan; Peng, Zhe; Li, Guangxue

2015-09-01

To investigate the utility of indocyanine green angiography in flap reconstructive surgery and possibility of decrease the complications. Indocyanine green angiography was performed on 14 patients undergoing flap reconstructive surgery between February and December 2014 to evaluate the blood perfusion of the flap and to adjust the operation plan. Of 14 cases, 2 were male and 12 were female, aged 23-58 years (mean, 35.5 years); 11 flaps were used for breast reconstruction [including 3 free deep inferior epigastric antery perforator (DIEP) flaps, 4 pedicled transverse rectus abdominis myocutaneous flaps (TRAM), 2 pedicled TRAM and free TRAM, and 2 pedicled latissimus dorsi myocutaneous flaps and prosthesis], 1 pedicled latissimus dorsi myocutaneous flap for repairing chest wall defect, 1 pedicled profunda artery perforator (PAP) flap for upper leg defect, and 1 pedicled descending genicular artery perforator flap for knee defect. The size of the flaps ranged from 9 cm x 6 cm to 26 cm x 12 cm. A total of 32 indocyanine green angiography were performed. There was no adverse reactions to the infusion of indocyanine green. The surgery management was adjusted according to results of indocyanine green angiography findings in 5 of 14 cases. The distal part of flap were discarded because of poor perfusion in 3 cases (1 DIEP flap, 1 TRAM, and 1 PAP flap) and the other 2 cases (pedicled TRAM) needed additional free anastomosis to ensure sufficient blood supply (pedicled TRAM and free TRAM); the other flaps were harvested according to preoperative plan and repaired defect successfully. The mean follow-up was 5 months (range, 1-9 months). The other flaps survived without infection or fat necrosis except 1 PAP flap with distal necrosis. Intraoperative indocyanine green angiography can provide real-time information of flap perfusion and then the operation plan can be adjusted in time to ensure the flap survival.

PIV Measurements on a Blowing Flap

NASA Technical Reports Server (NTRS)

Hutcheson, Florence V.; Stead, Daniel J.

2004-01-01

PIV measurements of the flow in the region of a flap side edge are presented for several blowing flap configurations. The test model is a NACA 63(sub 2)-215 Hicks Mod-B main-element airfoil with a half-span Fowler flap. Air is blown from small slots located along the flap side edge on either the top, bottom or side surfaces. The test set up is described and flow measurements for a baseline and three blowing flap configurations are presented. The effects that the flap tip jets have on the structure of the flap side edge flow are discussed for each of the flap configurations tested. The results indicate that blowing air from a slot located along the top surface of the flap greatly weakened the top vortex system and pushed it further off the top surface. Blowing from the bottom flap surface kept the strong side vortex further outboard while blowing from the side surface only strengthened the vortex system or accelerated the merging of the side vortex to the flap top surface. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

Long-Term Follow-Up of Flap Prefabrication in Facial Reconstruction.

PubMed

Wang, Weixin; Zhao, Muxin; Tang, Yong; Chen, Wen; Yang, Zhe; Ma, Ning; Xu, Lisi; Feng, Jun; Li, Yangqun

2017-07-01

Flap prefabrication is to turn a random flap into an axial flap by transferring a vascular pedicle. In the past 13 years, we have prefabricated 20 flaps in 20 patients by the superficial temporal artery and its concomitant veins. Typically, a 50- to 800-mL tissue expander was implanted in the donor site. After flap maturation, the prefabricated flap was raised and transferred locally to cover the large defect on the face. All the cases were followed up regularly. The patients' age were between 3 and 27 years, the size of the flaps were between 3.5 × 5.5 cm and 13 × 15 cm, the superficial temporal artery length was between 10 and 15 cm. All flaps were transferred successfully: 10 of the flaps had venous congestion, partial epidermis exfoliation and flap necrosis occurred in 4 flaps. All cases were followed up for at least 1 year, the longest follow-up period was 9 years. Long-term follow-up results showed the prefabricated flap survived in good condition and had a satisfactory outcome. Because flap prefabrication is practical, and long-term follow-ups have proved its preferable characters and stability, it is a fine method for large area facial reconstructions.

Long-Term Patency of Twisted Vascular Pedicles in Perforator-Based Propeller Flaps.

PubMed

Jakubietz, Rafael G; Nickel, Aljoscha; Neshkova, Iva; Schmidt, Karsten; Gilbert, Fabian; Meffert, Rainer H; Jakubietz, Michael G

2017-10-01

Propeller flaps require torsion of the vascular pedicle of up to 180 degrees. Contrary to free flaps, where the relevance of an intact vascular pedicle has been documented, little is known regarding twisted pedicles of propeller flaps. As secondary surgeries requiring undermining of the flap are common in the extremities, knowledge regarding the necessity to protect the pedicle is relevant. The aim of this study was a long-term evaluation of the patency of vascular pedicle of propeller flaps. In a retrospective clinical study, 22 patients who underwent soft-tissue reconstruction with a propeller flap were evaluated after 43 months. A Doppler probe was used to locate and evaluate the patency of the vascular pedicle of the flap. The flaps were used in the lower extremity in 19 cases, on the trunk in 3 cases. All flaps had healed. In all patients, an intact vascular pedicle could be found. Flap size, source vessel, or infection could therefore not be linked to an increased risk of pedicle loss. The vascular pedicle of propeller flaps remains patent in the long term. This allows reelevation and undermining of the flap. We therefore recommend protecting the pedicle in all secondary cases to prevent later flap loss.

New model of flap-gliding flight.

PubMed

Sachs, Gottfried

2015-07-21

A new modelling approach is presented for describing flap-gliding flight in birds and the associated mechanical energy cost of travelling. The new approach is based on the difference in the drag characteristics between flapping and non-flapping due to the drag increase caused by flapping. Thus, the possibility of a gliding flight phase, as it exists in flap-gliding flight, yields a performance advantage resulting from the decrease in the drag when compared with continuous flapping flight. Introducing an appropriate non-dimensionalization for the mathematical relations describing flap-gliding flight, results and findings of generally valid nature are derived. It is shown that there is an energy saving of flap-gliding flight in the entire speed range compared to continuous flapping flight. The energy saving reaches the highest level in the lower speed region. The travelling speed of flap-gliding flight is composed of the weighted average of the differing speeds in the flapping and gliding phases. Furthermore, the maximum range performance achievable with flap-gliding flight and the associated optimal travelling speed are determined. Copyright © 2015 Elsevier Ltd. All rights reserved.

Intercostal artery perforator propeller flap for reconstruction of trunk defects following sarcoma resection.

PubMed

Zang, Mengqing; Yu, Shengji; Xu, Libin; Zhao, Zhenguo; Zhu, Shan; Ding, Qiang; Liu, Yuanbo

2015-06-01

Trunk defects following soft tissue sarcoma resection are usually managed by myocutaneous flaps or free flaps. However, harvesting muscle will cause functional morbidities and some trunk regions lack reliable recipient vessels. The intercostal arteries give off multiple perforators, which distribute widely over the trunk and can supply various pedicle flaps. Our purpose is to use various intercostal artery perforator propeller flaps for trunk oncologic reconstruction. Between November 2013 and July 2014, nine intercostal artery perforator propeller flaps were performed in seven patients to reconstruct the defects following sarcoma resection in different regions of the trunk, including the back, lumbar, chest, and abdomen. Two perforators from intercostal arteries were identified for each flap using Doppler ultrasound probe adjacent to the defect. The perforator with visible pulsation was chosen as the pedicle vessel. An elliptical flap was raised and rotated in a propeller fashion to repair the defects. There were one dorsal intercostal artery perforator flap, four dorsolateral intercostal artery perforator flaps, three lateral intercostal artery perforator flaps, and one anterior intercostal artery perforator flap. The mean skin paddle dimension was 9.38 cm in width (range 6-14 cm) and 21.22 cm in length (range 13-28 cm). All intercostal artery perforator flaps survived completely, except for marginal necrosis in one flap harvested close to the previous flap donor site. The intercostal artery perforator propeller flap provides various and valuable options in our reconstructive armamentarium for trunk oncologic reconstruction. To our knowledge, this is the first case series of using intercostal artery perforator propeller flaps for trunk oncologic reconstruction and clinical application of dorsolateral intercostal artery perforator flaps. Copyright © 2015 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

An innovative method of planning and displaying flap volume in DIEP flap breast reconstructions.

PubMed

Hummelink, S; Verhulst, Arico C; Maal, Thomas J J; Hoogeveen, Yvonne L; Schultze Kool, Leo J; Ulrich, Dietmar J O

2017-07-01

Determining the ideal volume of the harvested flap to achieve symmetry in deep inferior epigastric artery perforator (DIEP) flap breast reconstructions is complex. With preoperative imaging techniques such as 3D stereophotogrammetry and computed tomography angiography (CTA) available nowadays, we can combine information to preoperatively plan the optimal flap volume to be harvested. In this proof-of-concept, we investigated whether projection of a virtual flap planning onto the patient's abdomen using a projection method could result in harvesting the correct flap volume. In six patients (n = 9 breasts), 3D stereophotogrammetry and CTA data were combined from which a virtual flap planning was created comprising perforator locations, blood vessel trajectory and flap size. All projected perforators were verified with Doppler ultrasound. Intraoperative flap measurements were collected to validate the determined flap delineation volume. The measured breast volume using 3D stereophotogrammetry was 578 ± 127 cc; on CTA images, 527 ± 106 cc flap volumes were planned. The nine harvested flaps weighed 533 ± 109 g resulting in a planned versus harvested flap mean difference of 5 ± 27 g (flap density 1.0 g/ml). In 41 out of 42 projected perforator locations, a Doppler signal was audible. This proof-of-concept shows in small numbers that flap volumes can be included into a virtual DIEP flap planning, and transferring the virtual planning to the patient through a projection method results in harvesting approximately the same volume during surgery. In our opinion, this innovative approach is the first step in consequently achieving symmetric breast volumes in DIEP flap breast reconstructions. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Medium- and Large-Sized Autologous Breast Reconstruction using a Fleur-de-lys Profunda Femoris Artery Perforator Flap Design: A Report Comparing Results with the Horizontal Profunda Femoris Artery Perforator Flap.

PubMed

Hunsinger, Vincent; Lhuaire, Martin; Haddad, Kevin; Wirz, Francesco-Saverio; Abedalthaqafi, Samah; Obadia, Déborah; Derder, Mohamed; Marchac, Alexandre; Benjoar, Marc David; Hivelin, Mikael; Lantieri, Laurent

2018-06-02

 The volume of the profunda femoris artery perforator (PAP) flap limits its indications to small- and medium-sized breast reconstructions after modified radical mastectomy for cancer. We report a modified PAP flap design, including not only a vertical extension that increases its volume but also the skin surface, which suits larger breasts requiring immediate or delayed breast reconstructions and compare the results with our horizontal skin paddle PAP flap experience.  In our center between November 2014 and November 2016, 51 consecutive patients underwent a PAP flap breast reconstruction following breast cancer. A retrospective analysis on the collected data was performed to compare 34 patients with a bra cup smaller than C who underwent 41 horizontal PAP flap procedures, with those ( n  = 17) of a bra cup greater than or equal to C who underwent 21 fleur-de-lys PAP flap procedures. Demographic, anthropometric, flap and surgical characteristics, postoperative complication rates, and hospital stay were compared between the two groups.  The average flap weight was 480 g (range: 340-735 g) for the fleur-de-lys PAP flap group compared with 222 g (range: 187-325 g) for the horizontal PAP flap procedure ( p  < 0.001). The mean flap dimensions were 25 × 18 cm for the fleur-de-lys PAP flap group compared with 25 × 7 cm in the horizontal PAP flap group. No flap failure was observed in the fleur-de-lys PAP flap group compared with two flap failures secondary to venous thrombosis in the horizontal PAP flap group ( NS ). Three patients (14%) experienced delayed healing at the donor site compared with four patients (10%) in the horizontal PAP flap group ( NS ).  The fleur-de-lys skin paddle design not only allows an increase of the horizontal PAP flap volume, but also increases the skin surface, with an acceptable donor site morbidity. For medium- or large-sized breasts, the fleur-de-lys PAP flap seems to be ideal when a DIEP flap-based reconstruction is contraindicated. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Free-style dual plane recycling tensor fascia lata musculocutaneous perforator flap for reconstruction of recurrent trochanteric defects.

PubMed

Han, Ba Leun; Choi, Hwan Jun

2014-03-01

Sequential flap coverage might be required for recurrent defects, but reusing a flap as a donor site has seldom been reported. The concept of a "free-style flap" has been developed, and it allows reconstructive surgeons to raise flaps with various designs reliably, even at sites of previous flap surgery. This article presents the concept of free-style recycling of a tensor fascia lata flap into a perforator-based flap separated in 2 planes in a patient with a recurrent bilateral trochanteric defect. If a reliable perforator is preserved and identified within the tissues by computed tomography angiography or a Doppler device, a new perforator flap can be designed and raised at the previous flap site.

Nonlinear flap-lag-extensional vibrations of rotating, pretwisted, preconed beams including Coriolis effects

NASA Technical Reports Server (NTRS)

Subrahmanyam, K. B.; Kaza, K. R. V.

1985-01-01

The effects of pretwist, precone, setting angle, Coriolis forces and second degree geometric nonlinearities on the natural frequencies, steady state deflections and mode shapes of rotating, torsionally rigid, cantilevered beams were studied. The governing coupled equations of flap lag extensional motion are derived including the effects of large precone and retaining geometric nonlinearities up to second degree. The Galerkin method, with nonrotating normal modes, is used for the solution of both steady state nonlinear equations and linear perturbation equations. Parametric indicating the individual and collective effects of pretwist, precone, Coriolis forces and second degree geometric nonlinearities on the steady state deflection, natural frequencies and mode shapes of rotating blades are presented. It is indicated that the second degree geometric nonlinear terms, which vanish for zero precone, can produce frequency changes of engineering significance. Further confirmation of the validity of including those generated by MSC NASTRAN. It is indicated that the linear and nonlinear Coriolis effects must be included in analyzing thick blades. The Coriolis effects are significant on the first flatwise and the first edgewise modes.

Simplicity and treatment of the typical cleft hand.

PubMed

Upton, J

2004-01-01

The typical cleft hand is now distinguished from symbrachydactyly. This review of the surgical treatment of 108 hands in 63 patients treated over a 28-year period concentrates upon the technical principles of surgical correction. The key to these reconstructions is a wide incision which extends from the ulnar side of the cleft around the malpositioned index finger to the thumb. This wide exposure provides clear identification of all anatomic structures within the palm. There are no tenuous flaps with narrow random pedicles. These difficult surgical corrections may often include index transposition, metacarpal and/or phalangeal osteotomies, joint releases, phalangeal ostectomies, preservation of the adductor pollicis muscle, first dorsal interosseous muscle release, syndactyly separation(s) and thumb duplication correction. Following reposition of all skeletal structures the dorsal and palmar full-thickness flaps are easily contoured to create a satisfactory first webspace. Outcomes data shows that although the pinch and grip remain weak, these hands are quite functional. It is important that the repositioned index ray not interfere with gripping and precision maneuvers between the mobile thumb and the ulnar two digits (ring and small) of the hand.

Foucher first dorsal metacarpal artery flap versus littler heterodigital neurovascular flap in resurfacing thumb pulp loss defects.

PubMed

Delikonstantinou, Iraklis P; Gravvanis, Andreas I; Dimitriou, Vasilios; Zogogiannis, Ioannis; Douma, Amalia; Tsoutsos, Dimosthenis A

2011-08-01

Our study aims to illustrate the advantages and disadvantages of Foucher's first dorsal metacarpal artery flap and Littler's heterodigital neurovascular flap in thumb pulp reconstruction, by assessing wound healing of donor and recipient sites, sensibility, and functional outcome of the reconstructed thumb. Fourteen male patients were reconstructed either with Foucher (n = 8) or Littler flap (n = 6). Dissection of Foucher's flap was faster than that of Littler's flap. All Littler flaps survived completely, but we experienced 1 partial Foucher flap necrosis. Thumb motility and stability was optimal in all patients. Wound healing of donor sites was achieved in both groups. Two patients reconstructed with Littler flap developed scar contractures and presented a reduced range of motion of donor finger and first webspace, respectively. Although Littler flap resulted in better sensibility and tactile gnosis of the reconstructed thumb-pulp, Foucher flap ensured negligible donor site morbidity, complete cortical reorientation, and better overall hand function.

Wind-Tunnel Investigation of an NACA 23021 Airfoil with a 0.32-Airfoil-Chord Double Slotted Flap

NASA Technical Reports Server (NTRS)

Fischel, Jack; Riebe, John M

1944-01-01

An investigation was made in the LMAL 7- by 10-foot wind tunnel of a NACA 23021 airfoil with a double slotted flap having a chord 32 percent of the airfoil chord (0.32c) to determine the aerodynamic section characteristics with the flaps deflected at various positions. The effects of moving the fore flap and rear flap as a unit and of deflecting or removing the lower lip of the slot were also determined. Three positions were selected for the fore flap and at each position the maximum lift of the airfoil was obtained with the rear flap at the maximum deflection used at that fore-flap position. The section lift of the airfoil increased as the fore flap was extended and maximum lift was obtained with the fore flap deflected 30 deg in the most extended position. This arrangement provided a maximum section lift coefficient of 3.31, which was higher than the value obtained with either a 0.2566c or a 0.40c single-slotted-flap arrangement and 0.25 less than the value obtained with a 0.4c double-slotted-flap arrangement on the same airfoil. The values of the profile-drag coefficient obtained with the 0.32c double slotted flap were larger than those for the 0.2566c or 0.40c single slotted flaps for section lift coefficients between 1.0 and approximately 2.7. At all values of the section lift coefficient above 1.0, the 0.40c double slotted flap had a lower profile drag than the 0.32c double slotted flap. At various values of the maximum section lift coefficient produced by various flap defections, the 0.32c double slotted flap gave negative section pitching-moment coefficients that were higher than those of other slotted flaps on the same airfoil. The 0.32c double slotted flap gave approximately the same maximum section lift coefficient as, but higher profile-drag coefficients over the entire lift range than, a similar arrangement of a 0.30c double slotted flap on an NACA 23012 airfoil.

Aeroelastic Modeling of Elastically Shaped Aircraft Concept via Wing Shaping Control for Drag Reduction

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; James Urnes, Sr.

2012-01-01

Lightweight aircraft design has received a considerable attention in recent years as a means for improving cruise efficiency. Reducing aircraft weight results in lower lift requirements which directly translate into lower drag, hence reduced engine thrust requirements during cruise. The use of lightweight materials such as advanced composite materials has been adopted by airframe manufacturers in current and future aircraft. Modern lightweight materials can provide less structural rigidity while maintaining load-carrying capacity. As structural flexibility increases, aeroelastic interactions with aerodynamic forces and moments become an increasingly important consideration in aircraft design and aerodynamic performance. Furthermore, aeroelastic interactions with flight dynamics can result in issues with vehicle stability and control. Abstract This paper describes a recent aeroelastic modeling effort for an elastically shaped aircraft concept (ESAC). The aircraft model is based on the rigid-body generic transport model (GTM) originally developed at NASA Langley Research Center. The ESAC distinguishes itself from the GTM in that it is equipped with highly flexible wing structures as a weight reduction design feature. More significantly, the wings are outfitted with a novel control effector concept called variable camber continuous trailing edge (VCCTE) flap system for active control of wing aeroelastic deflections to optimize the local angle of attack of wing sections for improved aerodynamic efficiency through cruise drag reduction and lift enhancement during take-off and landing. The VCCTE flap is a multi-functional and aerodynamically efficient device capable of achieving high lift-to-drag ratios. The flap system is comprised of three chordwise segments that form the variable camber feature of the flap and multiple spanwise segments that form a piecewise continuous trailing edge. By configuring the flap camber and trailing edge shape, drag reduction could be achieved. Moreover, some parts of the flap system can be made to have a high frequency response for roll control, gust load alleviation, and aeroservoelastic (ASE) modal suppression control. Abstract The aeroelastic model of the ESAC is based on one-dimensional structural dynamic theory that captures the aeroelastic deformation of a wing structure in a combined motion that involves flapwise bending, chordwise bending, and torsion. The model includes the effect of aircraft propulsion due to wing flexibility which causes the propulsive forces and moments to couple with the wing elastic motion. Engine mass is also accounted in the model. A fuel management model is developed to describe the wing mass change due to fuel usage in the main tank and wing tanks during cruise. Abstract The model computes both static and dynamic responses of the wing structures. The static aeroelastic deflections are used to estimate the effect of wing flexibility on induced drag and the potential drag reduction by the VCCTE flap system. A flutter analysis is conducted to estimate the flutter speed boundary. Gust load alleviation via adaptive control has been recently investigated to address flexibility of aircraft structures. A multi-objective flight control approach is presented for drag reduction control. The approach is based on an optimal control framework using a multi-objective cost function. Future studies will demonstrate the potential benefits of the approach.

The Economy in Autologous Tissue Transfer: Part 1. The Kiss Flap Technique.

PubMed

Zhang, Yi Xin; Hayakawa, Thomas J; Levin, L Scott; Hallock, Geoffrey G; Lazzeri, Davide

2016-03-01

All reconstructive microsurgeons realize the need to improve aesthetic and functional donor-site outcomes. A "kiss" flap design concept was developed to increase the surface area of skin flap coverage while minimizing donor-site morbidity. The main goal of the kiss flap technique is to harvest multiple skin paddles that are smaller than those raised with traditional techniques, to minimize donor-site morbidity. These smaller flap components are then sutured to each other, or said to kiss each other side-by-side, to create a large, wide flap. The skin paddles in the kiss technique can be linked to one another by a variety of native intrinsic vascular connections, by additional microanastomosis, or both. This technique can be widely applied to both free and pedicle flaps, and essentially allows for the reconstruction of a large defect while providing the easy primary closure of a smaller donor-site defect. According to their origin of blood supply, kiss flaps are classified into three styles and five types. All of the different types of kiss flaps are unique in both flap design and harvest technique. Most kiss flaps are based on common flaps already familiar to the reconstructive surgeon. The basis of the kiss flap design concept is to convert multiple narrow flaps into a single unified flap of the desired greater width. This maximizes the size of the resulting flap and minimizes donor-site morbidity, as a direct linear closure is usually possible. Therapeutic, V.

The Temporalis Muscle Flap for Palate Reconstruction: Case Series and Review of the Literature

PubMed Central

Brennan, Tara; Tham, Tristan M.; Costantino, Peter

2017-01-01

Introduction  The temporalis myofascial (TM) is an important reconstructive flap in palate reconstruction. Past studies have shown the temporalis myofascial flap to be safe as well as effective. Free flap reconstruction of palate defects is also a popular method used by contemporary surgeons. We aim to reaffirm the temporalis myofascial flap as a viable alternative to free flaps for palate reconstruction. Objective  We report our results using the temporalis flap for palate reconstruction in one of the largest case series reported. Our literature review is the first to describe complication rates of palate reconstruction using the TM flap. Methods  Retrospective chart review and review of the literature. Results  Fifteen patients underwent palate reconstruction with the TM flap. There were no cases of facial nerve injury. Five (33%) of these patients underwent secondary cranioplasty to address temporal hollowing after the TM flap. Three out of fifteen (20%) had flap related complications. Fourteen (93%) of the palate defects were successfully reconstructed, with the remaining case pending a secondary procedure to close the defect. Ultimately, all of the flaps (100%) survived. Conclusion  The TM flap is a viable method of palate defect closure with a high defect closure rate and flap survival rate. TM flaps are versatile in repairing palate defects of all sizes, in all regions of the palate. Cosmetic deformity created from TM flap harvest may be addressed using cranioplasty implant placement, either primarily or during a second stage procedure. PMID:28680495

Improved wound healing of postischemic cutaneous flaps with the use of bone marrow-derived stem cells.

PubMed

Hu, Melissa; Ludlow, David; Alexander, J Steven; McLarty, Jerry; Lian, Timothy

2014-03-01

To determine if the intravascular delivery of mesenchymal stem cells improves wound healing and blood perfusion to postischemic cutaneous flap tissues. Randomized controlled study. A murine model of a cutaneous flap was created based on the inferior epigastric vessels. Mice (n = 14) underwent 3.5 hours of ischemia followed by reperfusion. Bone marrow stromal cells (BMSCs) 1 × 10(6) were injected intravenously. Wound healing was then assessed measuring percent flap necrosis, flap perfusion, and tensile strength of the flap after a period of 14 days. Localization of BMSCs was determined with radiolabeled and fluorescent labeled BMSCs. Postischemic cutaneous flap tissues treated with BMSCs demonstrated significantly less necrosis than control flaps (P <0.01). Beginning on postoperative day 5, BMSC-treated flaps demonstrated greater blood perfusion than untreated flaps (P <0.01). Tensile strength of BMSC-treated cutaneous flaps was significantly higher (P <0.01), with a mean strength of 283.4 ± 28.4 N/m than control flaps with a mean of 122.4 ± 23.5 N/m. Radiolabeled BMSCs localized to postischemic flaps compared to untreated tissues (P = 0.001). Fluorescent microscopy revealed incorporation of BMSCs into endothelial and epithelial tissues of postischemic flaps. This study demonstrates that the intravascular delivery of BMSCs increases wound healing and promotes flap survival following ischemia-reperfusion injury of cutaneous tissue flaps. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

[A variant of island flaps for the covering of pressure sores: the hatchet flap. Apropos of 31 cases].

PubMed

Quillot, M; Lodde, J P; Pegorier, O; Reynaud, J P; Cormerais, A

1994-08-01

The authors propose a modification of the classical design of island flaps for cover of pressure sores, applied to gluteus maximus and tensor fascia lata muscles: the hatchet flap. 31 flaps have been used including 13 gluteus maximus superior flaps for sacral pressure sores, 9 gluteal inferior flaps for ischial pressure sores and 9 tensor fascia lata flaps for trochanteric pressure sores. A small partial necrosis and two cases of sepsis were observed in this series, but did not require surgical revision. The authors emphasize the value of this modification of the classical flap design, which preserves an even better musculocutaneous capital in these patients, who are often already multi-operated. The very rapid recovery of patients supports the authors' application of hatchet flaps to the surgery of pressure sores, and suggests the extension to other musculocutaneous flaps in the future.

Overview: Performance Adaptive Aeroelastic Wing

NASA Technical Reports Server (NTRS)

Hashemi, Kelley

2017-01-01

An overview of recent aeroelasitc wing-shaping work at the NASA Ames Research Center is presented. The highlight focuses on activity related to the Performance Adaptive Aeroelastic Wing concept and related Variable Camber Continuous Trailing Edge Flap actuation system. Topics covered include drag-reducing configurations and online algorithms, gust and maneuver load techniques, and wind tunnel demonstrations.

Model aerodynamic test results for two variable cycle engine coannular exhaust systems at simulated takeoff and cruise conditions. [Lewis 8 by 6-foot supersonic wind tunnel tests

NASA Technical Reports Server (NTRS)

Nelson, D. P.

1980-01-01

Wind tunnel tests were conducted to evaluate the aerodynamic performance of a coannular exhaust nozzle for a proposed variable stream control supersonic propulsion system. Tests were conducted with two simulated configurations differing primarily in the fan duct flowpaths: a short flap mechanism for fan stream control with an isentropic contoured flow splitter, and an iris fan nozzle with a conical flow splitter. Both designs feature a translating primary plug and an auxiliary inlet ejector. Tests were conducted at takeoff and simulated cruise conditions. Data were acquired at Mach numbers of 0, 0.36, 0.9, and 2.0 for a wide range of nozzle operating conditions. At simulated supersonic cruise, both configurations demonstrated good performance, comparable to levels assumed in earlier advanced supersonic propulsion studies. However, at subsonic cruise, both configurations exhibited performance that was 6 to 7.5 percent less than the study assumptions. At take off conditions, the iris configuration performance approached the assumed levels, while the short flap design was 4 to 6 percent less.

Dynamic Nonlinear Elastic Stability of Helicopter Rotor Blades in Hover and in Forward Flight

NASA Technical Reports Server (NTRS)

Friedmann, P.; Tong, P.

1972-01-01

Equations for large coupled flap-lag motion of hingeless elastic helicopter blades are consistently derived. Only torsionally-rigid blades excited by quasi-steady aerodynamic loads are considered. The nonlinear equations of motion in the time and space variables are reduced to a system of coupled nonlinear ordinary differential equations with periodic coefficients, using Galerkin's method for the space variables. The nonlinearities present in the equations are those arising from the inclusion of moderately large deflections in the inertia and aerodynamic loading terms. The resulting system of nonlinear equations has been solved, using an asymptotic expansion procedure in multiple time scales. The stability boundaries, amplitudes of nonlinear response, and conditions for existence of limit cycles are obtained analytically. Thus, the different roles played by the forcing function, parametric excitation, and nonlinear coupling in affecting the solution can be easily identified, and the basic physical mechanism of coupled flap-lag response becomes clear. The effect of forward flight is obtained with the requirement of trimmed flight at fixed values of the thrust coefficient.

The Anterior Interosseus Artery Perforator Flap: Anatomical Dissections and Clinical Study.

PubMed

Panse, Nikhil S; Joshi, Sheetal B; Sahasrabudhe, Parag B; Bahetee, B; Gurude, Pradnya; Chandanwale, Ajay

2017-05-01

Reconstruction of upper extremity deformities continues to be a challenge to the reconstructive surgeon. Various loco regional, distant and free flaps are available for reconstruction. However, each has its own set of advantages and disadvantages. Of the commonly performed local flaps, radial artery forearm flap, and the posterior interosseus artery flap stand out prominently. Recently, perforator propeller flaps have been used for resurfacing the upper extremity. The anterior interosseus artery perforator flap is an uncommonly used and described flap. This study was divided into anatomical study and clinical application in a IV level of evidence. In the anatomical study, five upper extremities were studied. Clinically, 12 patients underwent reconstruction using the anterior interosseus artery perforator flap. Flaps were performed by a single surgeon. A retrospective review of these cases from November 2008 to May 2014 is presented. The anterior interosseus artery perforator was identified in four out of five cadaver limbs. The septocutaneous perforator was in the fifth extensor compartment around 4 cm proximal to the wrist joint. Of the twelve flaps, there was complete necrosis in one flap, and partial necrosis in one flap. The patient with complete necrosis underwent skin grafting at a later date. The wound healed secondarily in case of partial flap necrosis. Anterior interosseus artery perforator flap must be considered as an important reconstructive option in the armamentarium of the plastic surgeon, while managing hand and wrist defects.

[Aesthetic effect of wound repair with flaps].

PubMed

Tan, Qian; Zhou, Hong-Reng; Wang, Shu-Qin; Zheng, Dong-Feng; Xu, Peng; Wu, Jie; Ge, Hua-Qiang; Lin, Yue; Yan, Xin

2012-08-01

To investigate the aesthetic effect of wound repair with flaps. One thousand nine hundred and ninety-six patients with 2082 wounds hospitalized from January 2004 to December 2011. These wounds included 503 deep burn wounds, 268 pressure sores, 392 soft tissue defects caused by trauma, 479 soft tissue defects due to resection of skin cancer and mole removal, 314 soft tissue defects caused by scar excision, and 126 other wounds. Wound area ranged from 1.5 cm x 1.0 cm to 30.0 cm x 22.0 cm. Sliding flaps, expanded flaps, pedicle flaps, and free flaps were used to repair the wounds in accordance with the principle and timing of wound repair with flaps. Five flaps showed venous congestion within 48 hours post-operation, 2 flaps of them improved after local massage. One flap survived after local heparin wet packing and venous bloodletting. One flap survived after emergency surgical embolectomy and bridging with saphenous vein graft. One flap showed partial necrosis and healed after skin grafting. The other flaps survived well. One thousand three hundred and twenty-one patients were followed up for 3 months to 2 years, and flaps of them were satisfactory in shape, color, and elasticity, similar to that of normal skin. Some patients underwent scar revision later with good results. Application of suitable flaps in wound repair will result in quick wound healing, good function recovery, and satisfactory aesthetic effect.

Wind-Tunnel Investigation of a Rectangular NACA 2212 Airfoil with Semispan Ailerons and with Nonperforated, Balanced Double Split Flaps for Use as Aerodynamic Brakes

NASA Technical Reports Server (NTRS)

Ivey, Margaret F

1945-01-01

Flat-plate flaps with no wing cutouts and flaps having Clark Y sections with corresponding cutouts made in wing were tested for various flap deflections, chord-wise locations, and gaps between flaps and airfoil contour. The drag was slightly lower for wing with airfoil section flaps. Satisfactory aileron effectiveness was obtained with flap gap of 20% wing chord and flap-nose location of 80 percent wing chord behind leading edge. Airflow was smooth and buffeting negligible.

[Pedicle flap of nasal septum-basis nasi and temporal muscucofascial flap to repair nasoseptal perforation].

PubMed

Yin, Xinghong; Hu, Wei; Zhang, Xinhai; Sun, Min

2014-10-01

To explore curative effect with pedicle flap of nasal septum-basis nasi and temporal muscucofascial flap to repair nasal septal perforation. Dissecting mucoperichondrium and mucoperioseptum around the perforation and taking dowm and out xia-ward to the floor of nasal cavity to make a inferior extremity pedicle flap. Then,the flap was tumbled and sutured onto raw surface of contralateral side through perforation. Reapplicating autoallergic temporal musculofascial flap to repair another side perforation. Repairing perforation Sin twelve cases were sucessfully healed in endoscope. The pedicle flap of nasal septum-basis nasi and temporal muscucofascial flap is easy to acquire and no rejection. The flap has good blood supplying, high survival rate and provides adequate transplantating materail to repair comparatively large perforation.

[The repair of bulky tissue defect of forearm with skin flaps].

PubMed

Huang, Xiaoyuan; Long, Jianhong; Xie, Tinghong; Zhang, Minghua; Zhang, Pihong; Yang, Xinghua; Zhong, Keqin

2002-12-01

To evaluate the repairing methods of bulky tissue defect of forearm with flaps. Twenty-one burned patients with wounds in the forearm were enrolled in this study. The injury causes were high-voltage electricity, hot press or crush injury. After local debridement, the forearm defects were repaired with pedicled complex flaps, latissimus dorsi musculocutaneous island flaps or large thoraco-abdominal flaps immediately. All the flaps survived very well with satisfactory results except for 1 patient in whom local ischemic necrosis and sub-flap infection at the distal end of the flap occurred. Early debridement followed by skin flaps with pedicles or musculocutaneous flaps transfer could be simple, safe and reliable treatment strategies in the management of bulky tissue defects of the forearm due to burn, electric injury, or other devastating injuries.

The perforator pedicled propeller (PPP) flap method: report of two cases.

PubMed

Hyakusoku, Hiko; Ogawa, Rei; Oki, Koichiro; Ishii, Nobuaki

2007-10-01

Perforator flaps are thin free-tissue transfers consisting of skin and subcutaneous tissue which have the advantage of decreasing donor site morbidity. We have reconstructed postburn scar contractures using "propeller flaps" of the remaining healthy skin around the recipient sites. In this paper, we report on two cases and describe the concept of using "perforator flaps" and "propeller flaps" together as what are called "perforator pedicled propeller (PPP) flaps." Patient 1 was an 18-year-old man with a sacral pressure ulcer. The soft tissue defect was reconstructed with a rotated superior gluteal artery PPP flap. Patient 2 was a 53-year-old woman who presented with an open fracture of the right elbow. The skin defect over the fracture was covered with a rotated deep brachial artery PPP flap raised on the lateral upper arm. The PPP flaps are useful for burn reconstruction and repairing various types of wound. Moreover, microsurgery is unnecessary. The PPP flap may be classified into two types: the central axis type and the acentric axis type. The central axis PPP flap is significant when used as a 90-degree-rotation island flap, and the acentric axis PPP flap is significant when used as a 180-degree-rotation island flap. Both types are easy to harvest and useful for repairing various kinds of wound.

The "Tokyo" consensus on propeller flaps.

PubMed

Pignatti, Marco; Ogawa, Rei; Hallock, Geoffrey G; Mateev, Musa; Georgescu, Alexandru V; Balakrishnan, Govindasamy; Ono, Shimpei; Cubison, Tania C S; D'Arpa, Salvatore; Koshima, Isao; Hyakusoku, Hikko

2011-02-01

Over the past few years, the use of propeller flaps, which base their blood supply on subcutaneous tissue or isolated perforators, has become increasingly popular. Because no consensus has yet been reached on terminology and nomenclature of the propeller flap, different and confusing uses of the term can be found in the literature. In this article, the authors report the consensus on the definition and classification of propeller flaps reached by the authors that gathered at the First Tokyo Meeting on Perforator and Propeller Flaps in June of 2009. Some peculiar aspects of the surgical technique are discussed. A propeller flap can be defined as an "island flap that reaches the recipient site through an axial rotation." The classification is based on the nourishing pedicle (subcutaneous pedicled propeller flap, perforator pedicled propeller flap, supercharged propeller flap), the degrees of skin island rotation (90 to 180 degrees) and, when possible, the artery of origin of the perforator. The propeller flap is a useful reconstructive tool that can achieve good cosmetic and functional results. A flap should be called a propeller flap only if it fulfils the definition above. The type of nourishing pedicle, the source vessel (when known), and the degree of skin island rotation should be specified for each flap.

Plastic Surgery Challenges in War Wounded I: Flap-Based Extremity Reconstruction

PubMed Central

Sabino, Jennifer M.; Slater, Julia; Valerio, Ian L.

2016-01-01

Scope and Significance: Reconstruction of traumatic injuries requiring tissue transfer begins with aggressive resuscitation and stabilization. Systematic advances in acute casualty care at the point of injury have improved survival and allowed for increasingly complex treatment before definitive reconstruction at tertiary medical facilities outside the combat zone. As a result, the complexity of the limb salvage algorithm has increased over 14 years of combat activities in Iraq and Afghanistan. Problem: Severe poly-extremity trauma in combat casualties has led to a large number of extremity salvage cases. Advanced reconstructive techniques coupled with regenerative medicine applications have played a critical role in the restoration, recovery, and rehabilitation of functional limb salvage. Translational Relevance: The past 14 years of war trauma have increased our understanding of tissue transfer for extremity reconstruction in the treatment of combat casualties. Injury patterns, flap choice, and reconstruction timing are critical variables to consider for optimal outcomes. Clinical Relevance: Subacute reconstruction with specifically chosen flap tissue and donor site location based on individual injuries result in successful tissue transfer, even in critically injured patients. These considerations can be combined with regenerative therapies to optimize massive wound coverage and limb salvage form and function in previously active patients. Summary: Traditional soft tissue reconstruction is integral in the treatment of war extremity trauma. Pedicle and free flaps are a critically important part of the reconstructive ladder for salvaging extreme extremity injuries that are seen as a result of the current practice of war. PMID:27679751

Clinical evaluation and comparison of the efficacy of coronally advanced flap alone and in combination with platelet rich fibrin membrane in the treatment of Miller Class I and II gingival recessions

PubMed Central

Gupta, Santosh; Banthia, Ruchi; Singh, Pallavi; Banthia, Priyank; Raje, Sapna; Aggarwal, Neha

2015-01-01

Background: The aim of this study was to compare the clinical efficacy of coronally advanced flap (CAF) alone and in combination with autologous platelet rich fibrin membrane (PRF) in Miller's class I and II gingival recessions. Materials and Method: Thirty isolated Miller class I or II sites in 26 subjects were randomly divided into test (15 sites- CAF+PRF) and control (15 sites- CAF alone). Parameters probing pocket depth (PPD), Recession depth (RD), Clinical attachment loss (CAL), Keratinised tissue width (KTW) and Gingival tissue thickness (GTH) were evaluated at baseline, 3 months and 6 months postoperatively. Data was subjected to statistical analysis. P< 0.05 was considered statistically significant. Results: Mean percentage root coverage was 91.00±19.98% and 86.60±23.83% for test and control group respectively. Difference between the groups in all parameters at baseline, 3 months and 6 months was non significant. Complete root coverage was obtained in 12 (80%) and 11 (73.3%) subjects in test and control group respectively. The difference was found to be non-significant. Both groups showed significant differences in all parameters at 3 and 6 months respectively except difference in gingival tissue thickness which was non-significant in control group at 3 months. Conclusion: Combination of PRF to CAF procedure did not provide any added advantage in term of recession coverage in Miller class I and II recessions. Long term trials with more sample size are needed to validate these findings. PMID:26097347

Supraclavicular artery perforator flap in management of post-burn neck reconstruction: clinical experience

PubMed Central

Ismail, H.; Elshobaky, A.

2016-01-01

Summary Anterior cervical contractures of the neck represent a great challenge for plastic and reconstructive surgeons. Necks can be reconstructed with a wide range of surgical techniques, including chimeric flaps, supercharged flap, pre-expanded flaps, “superthin” flaps and perforator flaps. The supraclavicular flap is easy to harvest without the need for free tissue transfer. It provides a relatively large flap for neck resurfacing with tissue very similar to that of the neck. Between January 2013 and March 2015, 20 patients suffering from postburn neck contracture underwent reconstruction with 20 unilateral supraclavicular artery perforator flaps. Nineteen patients had post-burn neck contractures (9 cases type Іc, 10 cases type Пc) while only one had post-burn granulation tissue in the neck. We harvested fifteen flaps from the right side and five from the left. Size of the reconstructed defect ranged from 23x10 to14x6, and flap size varied from 25/11 to 16/7cm. Period of follow up ranged from 27-2months (average 12.3). Nineteen flaps survived well (95% survival rate): only one was lost due to iatrogenic extensive dissection over the pedicle. Five cases showed distal superficial epidermolysis, and 2 cases showed 2 cm complete distal necrosis. All patients were managed conservatively. Our results coincide with other literature results confirming the efficacy and rich vascularity of this flap. In all cases with distal partial necrosis, flaps were 23 cm or more. We recommend that supraclavicular flaps of more than 22 cm in length are not harvested immediately and that flaps are expanded before harvesting. Expanding the supraclavicular flap increases its surface area and decreases donor site morbidity. PMID:28149252

Cracking the perfusion code?: Laser-assisted Indocyanine Green angiography and combined laser Doppler spectrophotometry for intraoperative evaluation of tissue perfusion in autologous breast reconstruction with DIEP or ms-TRAM flaps.

PubMed

Ludolph, Ingo; Arkudas, Andreas; Schmitz, Marweh; Boos, Anja M; Taeger, Christian D; Rother, Ulrich; Horch, Raymund E; Beier, Justus P

2016-10-01

The aim of this prospective study was to assess the correlation of flap perfusion analysis based on laser-assisted Indocyanine Green (ICG) angiography with combined laser Doppler spectrophotometry in autologous breast reconstruction using free DIEP/ms-TRAM flaps. Between February 2014 and July 2015, 35 free DIEP/ms-TRAM flaps were included in this study. Besides the clinical evaluation of flaps, intraoperative perfusion dynamics were assessed by means of laser-assisted ICG angiography and post-capillary oxygen saturation and relative haemoglobin content (rHb) using combined laser Doppler spectrophotometry. Correlation of the aforementioned parameters was analysed, as well as the impact on flap design and postoperative complications. Flap survival rate was 100%. There were no partial flap losses. In three cases, flap design was based on the angiography, contrary to clinical evaluation and spectrophotometry. The final decision on the inclusion of flap areas was based on the angiographic perfusion pattern. Angiography and spectrophotometry showed a correlation in most of the cases regarding tissue perfusion, post-capillary oxygen saturation and relative haemoglobin content. Laser-assisted ICG angiography is a useful tool for intraoperative evaluation of flap perfusion in autologous breast reconstruction with DIEP/ms-TRAM flaps, especially in decision making in cases where flap perfusion is not clearly assessable by clinical signs and exact determination of well-perfused flap margins is difficult to obtain. It provides an objective real-time analysis of flap perfusion, with high sensitivity for the detection of poorly perfused flap areas. Concerning the topographical mapping of well-perfused flap areas, laser-assisted angiography is superior to combined laser Doppler spectrophotometry. Copyright © 2016 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Full-scale-wind-tunnel Tests of a 35 Degree Sweptback Wing Airplane with High-velocity Blowing over the Training-edge Flaps

NASA Technical Reports Server (NTRS)

Kelley, Mark W; Tolhurst, William H JR

1955-01-01

A wind-tunnel investigation was made to determine the effects of ejecting high-velocity air near the leading edge of plain trailing-edge flaps on a 35 degree sweptback wing. The tests were made with flap deflections from 45 degrees to 85 degrees and with pressure ratios across the flap nozzles from sub-critical up to 2.9. A limited study of the effects of nozzle location and configuration on the efficiency of the flap was made. Measurements of the lift, drag, and pitching moment were made for Reynolds numbers from 5.8 to 10.1x10(6). Measurements were also made of the weight rate of flow, pressure, and temperature of the air supplied to the flap nozzles.The results show that blowing on the deflected flap produced large flap lift increments. The amount of air required to prevent flow separation on the flap was significantly less than that estimated from published two-dimensional data. When the amount of air ejected over the flap was just sufficient to prevent flow separation, the lift increment obtained agreed well with linear inviscid fluid theory up to flap deflections of 60 degrees. The flap lift increment at 85 degrees flap deflection was about 80 percent of that predicted theoretically.With larger amounts of air blown over the flap, these lift increments could be significantly increased. It was found that the performance of the flap was relatively insensitive to the location of the flap nozzle, to spacers in the nozzle, and to flow disturbances such as those caused by leading-edge slats or discontinuities on the wing or flap surfaces. Analysis of the results indicated that installation of this system on an F-86 airplane is feasible.

Evolution in Monitoring of Free Flap Autologous Breast Reconstruction after Nipple-Sparing Mastectomy: Is There a Best Way?

PubMed

Frey, Jordan D; Stranix, John T; Chiodo, Michael V; Alperovich, Michael; Ahn, Christina Y; Allen, Robert J; Choi, Mihye; Karp, Nolan S; Levine, Jamie P

2018-05-01

Free flap monitoring in autologous reconstruction after nipple-sparing mastectomy remains controversial. The authors therefore examined outcomes in nipple-sparing mastectomy with buried free flap reconstruction versus free flap reconstruction incorporating a monitoring skin paddle. Autologous free flap reconstructions with nipple-sparing mastectomy performed from 2006 to 2015 were identified. Demographics and operative results were analyzed and compared between buried flaps and those with a skin paddle for monitoring. Two hundred twenty-one free flaps for nipple-sparing mastectomy reconstruction were identified: 50 buried flaps and 171 flaps incorporating a skin paddle. The most common flaps used were deep inferior epigastric perforator (64 percent), profunda artery perforator (12.1 percent), and muscle-sparing transverse rectus abdominis myocutaneous flaps (10.4 percent). Patients undergoing autologous reconstructions with a skin paddle had a significantly greater body mass index (p = 0.006). Mastectomy weight (p = 0.017) and flap weight (p < 0.0001) were significantly greater in flaps incorporating a skin paddle. Comparing outcomes, there were no significant differences in flap failure (2.0 percent versus 2.3 percent; p = 1.000) or percentage of flaps requiring return to the operating room (6.0 percent versus 4.7 percent; p = 0.715) between groups. Buried flaps had an absolute greater mean number of revision procedures per nipple-sparing mastectomy (0.82) compared with the skin paddle group (0.44); however, rates of revision procedures per nipple-sparing mastectomy were statistically equivalent between the groups (p = 0.296). Although buried free flap reconstruction in nipple-sparing mastectomy has been shown to be safe and effective, the authors' technique has evolved to favor incorporating a skin paddle, which allows for clinical monitoring and can be removed at the time of secondary revision. Therapeutic, III.

Refining the cross-finger flap: Considerations of flap insetting, aesthetics and donor site morbidity.

PubMed

Chong, Chew-Wei; Lin, Cheng-Hung; Lin, Yu-Te; Hsu, Chung-Chen; Chen, Shih-Heng

2018-04-01

We described a laterally based cross-finger flap for reconstruction of soft tissue defects in the fingers. This modification enables coverage of volar or dorsal soft tissue defects at the distal, middle or proximal phalanx. From March 2015 to January 2017, a total of 12 patients (13 fingers) underwent soft tissue reconstruction of the fingers with a laterally based cross-finger flap. The flap dimensions ranged from 13 ×7 mm to 43 ×13 mm. Eleven of the 13 flaps survived completely. The two flap failures were attributed to injuries in the donor fingers, rendering the blood supply of the flaps unreliable. All donor sites were closed primarily without the need for skin grafting, negating the problem of donor site morbidity that is associated with skin graft harvesting. The laterally based cross-finger flap is a versatile flap with less donor site morbidity and better aesthetics than a conventional cross-finger flap. We described the design of the flap, as well as the advantages and disadvantages, in doing a laterally based cross-finger flap. Copyright © 2017 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Propeller Perforator Flaps in Distal Lower Leg: Evolution and Clinical Applications

PubMed Central

2012-01-01

Simple or complex defects in the lower leg, and especially in its distal third, continue to be a challenging task for reconstructive surgeons. A variety of flaps were used in the attempt to achieve excellence in form and function. After a long evolution of the reconstructive methods, including random pattern flaps, axial pattern flaps, musculocutaneous flaps and fasciocutaneous flaps, the reappraisal of the works of Manchot and Salmon by Taylor and Palmer opened the era of perforator flaps. This era began in 1989, when Koshima and Soeda, and separately Kroll and Rosenfield described the first applications of such flaps. Perforator flaps, whether free or pedicled, gained a high popularity due to their main advantages: decreasing donor-site morbidity and improving aesthetic outcome. The use as local perforator flaps in lower leg was possible due to a better understanding of the cutaneous circulation, leg vascular anatomy, angiosome and perforasome concepts, as well as innovations in flaps design. This review will describe the evolution, anatomy, flap design, and technique of the main distally pedicled propeller perforator flaps used in the reconstruction of defects in the distal third of the lower leg and foot. PMID:22783507

Free versus perforator-pedicled propeller flaps in lower extremity reconstruction: What is the safest coverage? A meta-analysis.

PubMed

Bekara, Farid; Herlin, Christian; Somda, Serge; de Runz, Antoine; Grolleau, Jean Louis; Chaput, Benoit

2018-01-01

Currently, increasingly reconstructive surgeon consider the failure rates of perforator propeller flaps especially in the distal third of the lower leg are too important and prefer to return to the use of free flap at first line option with failure rates frequently lower than 5%. So, we performed a systematic review with meta-analysis comparing free flaps (perforator-based or not) and pedicled-propeller flaps to respond to the question "what is the safest coverage for distal third of the lower limb?" This review was conducted according to PRISMA criteria. From 1991 to 2015, MEDLINE®, Pubmed central, Embase and Cochrane Library were searched. The pooled estimations were performed by meta-analysis. The homogeneity Q statistic and the I 2 index were computed. We included 36 articles for free flaps (1,226 flaps) and 19 articles for pedicled-propeller flaps (302 flaps). The overall failure rate was 3.9% [95%CI:2.6-5.3] for free flaps and 2.77% [95%CI:0.0-5.6] for pedicled-propeller flaps (P = 0.36). The complication rates were 19.0% for free flaps and 21.4% for pedicled-propeller flaps (P = 0.37). In more detail, we noted for free flaps versus pedicled-propeller flaps: partial necrosis (2.70 vs. 6.88%, P = 0.001%), wound dehiscence (2.38 vs. 0.26%, P = 0.018), infection (4.45 vs. 1.22%, P = 0.009). The coverage failure rate was 5.24% [95%CI:3.68-6.81] versus 2.99% [95%CI:0.38-5.60] without significant difference (P = 0.016). In the lower limb the complications are not rare and many teams consider the free flaps to be safer. In this meta-analysis we provide evidence that failure and overall complications rate of perforator propeller flaps are comparable with free flaps. Although, partial necrosis is significantly higher for pedicled-propeller flaps than free flaps, in reality the success of coverage appears similar. © 2016 Wiley Periodicals, Inc. Microsurgery, 38:109-119, 2018. © 2016 Wiley Periodicals, Inc.

Investigation of Full-Scale Split Trailing-Edge Wing Flaps with Various Chords and Hinge Locations

NASA Technical Reports Server (NTRS)

Wallace, Rudolf

1936-01-01

This report gives the results of an investigation conducted in the NACA full-scale wind tunnel on a small parasol monoplane equipped with three different split trailing-edge wing flaps. The object of the investigation was to determine and correlate data on the characteristics of the airplane and flaps as affected by variation in flap chord, flap deflection, and flap location along the wing chord. The results give the lift, the drag, and the pitching moment characteristics of the airplane, and the flap forces and moments, the pressure distribution over the flaps and wing at one section, and the downwash characteristics of the flap and wing combinations.

Surgical therapy of vulvar cancer: how to choose the correct reconstruction?

PubMed Central

2016-01-01

Objective To create a comprehensive algorithmic approach to reconstruction after vulvar cancer ablative surgery, which includes both traditional and perforator flaps, evaluating anatomical subunits and shape of the defect. Methods We retrospectively reviewed 80 cases of reconstruction after vulvar cancer ablative surgery, performed between June 2006 and January 2016, transferring 101 flaps. We registered the possibility to achieve the complete wound closure, even in presence of very complex defects, and the postoperative complications. On the basis of these experience, analyzing the choices made and considering the complications, we developed an algorithm to help with the selection of the flap in vulvoperineal reconstruction after oncologic ablative surgery for vulvar cancer. Results We employed eight types of different flaps, including 54 traditional fasciocutaneous V-Y flaps, 23 rectus abdominis myocutaneous flaps, 11 anterolateral thigh flaps, three V-Y gracilis myocutaneous flaps, three free style perforators V-Y flaps from the inner thigh, two Limberg flaps, two lotus flaps, two deep inferior epigastric artery perforator flap, and one superficial circumflex iliac artery perforator flap. The structures most frequently involved in resection were vulva, perineum, mons pubis, groins, vagina, urethra and, more rarely, rectum, bladder, and lower abdominal wall. Conclusion The algorithm we implemented can be a useful tool to help flap selection. The key points in the decision-making process are: anatomical subunits to be covered, overall shape and symmetry of the defect and some patient features such as skin laxity or previous radiotherapy. Perforator flaps, when feasible, must be considered standard in vulvoperineal reconstruction, although in some cases traditional flaps remain the best choice. PMID:27550406

Reconstruction of Complex Facial Defects Using Cervical Expanded Flap Prefabricated by Temporoparietal Fascia Flap.

PubMed

Zhang, Ling; Yang, Qinghua; Jiang, Haiyue; Liu, Ge; Huang, Wanlu; Dong, Weiwei

2015-09-01

Reconstruction of complex facial defects using cervical expanded flap prefabricated by temporoparietal fascia flap. Complex facial defects are required to restore not only function but also aesthetic appearance, so it is vital challenge for plastic surgeons. Skin grafts and traditional flap transfer cannot meet the reconstructive requirements of color and texture with recipient. The purpose of this sturdy is to create an expanded prefabricated temporoparietal fascia flap to repair complex facial defects. Two patients suffered severe burns on the face underwent complex facial resurfacing with prefabricated cervical flap. The vasculature of prefabricated flap, including the superficial temporal vessel and surrounding fascia, was used as the vascular carrier. The temporoparietal fascia flap was sutured underneath the cervical subcutaneous tissue, and expansion was begun in postoperative 1 week. After 4 to 6 months of expansion, the expander was removed, facial scars were excised, and cervical prefabricated flap was elevated and transferred to repair the complex facial defects. Two complex facial defects were repaired successfully by prefabricated temporoparietal fascia flap, and prefabricated flaps survived completely. On account of donor site's skin was thinner and expanded too fast, 1 expanded skin flap was rupture during expansion, but necrosis was not occurred after the 2nd operation. Venous congestion was observed in 1 patient, but after dressing, flap necrosis was not happened. Donor site was closed primarily. Postoperative follow-up 6 months, the color, texture of prefabricated flap was well-matched with facial skin. This method of expanded prefabricated flap may provide a reliable solution to the complex facial resurfacing.

Reconstruction of Large Postburn Facial-Scalp Scars by Expanded Pedicled Deltopectoral Flap and Random Scalp Flap: Technique Improvements to Enlarge the Reconstructive Territory.

PubMed

Ma, Xianjie; Li, Yang; Li, Weiyang; Liu, Chaohua; Peng, Pai; Song, Baoqiang; Xia, Wensen; Yi, Chenggang; Lu, Kaihua; Su, Yingjun

2017-09-01

The scars of face and scalp caused by burning often show as 1 large facial-scalp scar. The deltopectoral flap was recognized as one of the first choices for the facial scar reconstruction. However, this flap cannot cross the level of zygomatic arch traditionally when it was transferred with pedicle. When the flap reconstructed the facial-scalp scars with expanded random scalp flap, another flap was often needed to reconstruct the remaining temple and forehead scars. The authors reviewed 24 patients of large facial-scalp scars reconstructed by expanded pedicled deltopectoral flap and scalp flap with several technique improvements. The seaming scar between the deltopectoral flap and scalp flap in the temple region formed the new hairline. The technique improvements included ligation of the perforating branches of the transverse cervical artery and thoracoacromial artery when dissecting the pocket, the partial bolster compressive dressing to the distal part of the flap and dividing the pedicle partly as a delaying procedure before dividing the pedicle completely. Good skin compliance, normal contours, and emotional expression were noted. There were complications including expander exposure in 3 patients, stretch marks in 5 patients, flap tip necrosis in 2 patients, and mild postoperative hypertrophic scars in 3 patients. In conclusion, the expanded pedicled deltopectoral flap can enlarge the reconstructive territory in face successfully with the technique improvements. The combination of the expanded pedicled deltopectoral flap and scalp flap is a reliable and excellent reconstructive option for large postburn facial-scalp scars.

Free style perforator based propeller flaps: Simple solutions for upper extremity reconstruction!

PubMed

Panse, Nikhil; Sahasrabudhe, Parag

2014-01-01

The introduction of perforator flaps by Koshima et al. was met with much animosity in the plastic surgery fraternity. The safety concerns of these flaps following the intentional twist of the perforators have prevented widespread adoption of this technique. Use of perforator based propeller flaps in the lower extremity is gradually on the rise, but their use in upper extremity reconstruction is infrequently reported, especially in the Indian subcontinent. We present a retrospective series of 63 free style perforator flaps used for soft tissue reconstruction of the upper extremity from November 2008 to June 2013. Flaps were performed by a single surgeon for various locations and indications over the upper extremity. Patient demographics, surgical indication, defect features, complications and clinical outcome are evaluated and presented as an uncontrolled case series. 63 free style perforator based propeller flaps were used for soft tissue reconstruction of 62 patients for the upper extremity from November 2008 to June 2013. Of the 63 flaps, 31 flaps were performed for trauma, 30 for post burn sequel, and two for post snake bite defects. We encountered flap necrosis in 8 flaps, of which there was complete necrosis in 4 flaps, and partial necrosis in four flaps. Of these 8 flaps, 7 needed a secondary procedure, and one healed secondarily. Although we had a failure rate of 12-13%, most of our failures were in the early part of the series indicative of a learning curve associated with the flap. Free style perforator based propeller flaps are a reliable option for coverage of small to moderate sized defects. Therapeutic IV.

Parasacral Perforator Flaps for Reconstruction of Sacral Pressure Sores.

PubMed

Lin, Chin-Ta; Chen, Shih-Yi; Chen, Shyi-Gen; Tzeng, Yuan-Sheng; Chang, Shun-Cheng

2015-07-01

Despite advances in reconstruction techniques, pressure sores continue to present a challenge to the plastic surgeon. The parasacral perforator flap is a reliable flap that preserves the entire contralateral side as a future donor site. On the ipsilateral side, the gluteal muscle itself is preserved and all flaps based on the inferior gluteal artery are still possible. We present our experience of using parasacral perforator flaps in reconstructing sacral defects. Between August 2004 and January 2013, 19 patients with sacral defects were included in this study. All the patients had undergone surgical reconstruction of sacral defects with a parasacral perforator flap. The patients' sex, age, cause of sacral defect, flap size, flap type, numbers of perforators used, rotation angle, postoperative complications, and hospital stay were recorded. There were 19 parasacral perforator flaps in this series. All flaps survived uneventfully except for 1 parasacral perforator flap, which failed because of methicillin-resistant Staphylococcus aureus infection. The overall flap survival rate was 95% (18/19). The mean follow-up period was 17.3 months (range, 2-24 months). The average length of hospital stay was 20.7 days (range, 9-48 days). No flap surgery-related mortality was found. Also, there was no recurrence of sacral pressure sores or infected pilonidal cysts during the follow-up period. Perforator-based flaps have become popular in modern reconstructive surgery because of low donor-site morbidity and good preservation of muscle. Parasacral perforator flaps are durable and reliable in reconstructing sacral defects. We recommend the parasacral perforator flap as a good choice for reconstructing sacral defects.

Improving Pressure Ulcer Reconstruction: Our Protocol and the COP (Cone of Pressure) Flap

PubMed Central

Edstrom, Lee; Szymanski, Karen; Schmidt, Scott; Bevivino, Jack; Zienowicz, Richard; Stark, Jennifer; Taylor, Helena O.; Podda, Silvio; Liu, Paul

2017-01-01

Background: Surgical treatment of pressure ulcers is challenging for high recurrence rates. Deepithelialized flaps have been used previously with the aim to eliminate shearing forces and the cone of pressure (COP) effect. The goal of this study is to adopt a standardized protocol and evaluate if 2 different flap techniques affect outcomes. Methods: The novel COP flap is illustrated. Twenty patients were prospectively treated with flap coverage over a 36-month period. According to the flap type, patients were assigned to 2 groups: group 1 with 11 patients treated with the COP flap and group 2 with 9 patients treated with conventional flap without anchoring technique. We adopted a standardized protocol of debridement, tissue cultures, and negative-pressure wound therapy. Rotation fasciocutaneous flaps were used for both groups and mean follow-up was 19 months. The COP flap is a large deepithelialized rotation flap inset with transcutaneous nonabsorbable bolster sutures. The 2 groups were comparable for demographics and ulcer location and size (P < 0.05). Five patients showed positive cultures and were treated with antibiotics and negative-pressure therapy before surgery. Results: Recurrence rates were 12% in the COP flap group and 60% in the conventional flap coverage group (P < 0.001). Results were compared at 16-month follow-up. Conclusions: The COP flap significantly reduces recurrences and eliminates shearing forces, suture ripping, and tension on superficial soft-tissue layers. The technique can be applied to both ischial and sacral pressure sores. The flap provides padding over bony prominence without jeopardizing flap vascularity. PMID:28458961

Adaptive Neural Network Control of a Flapping Wing Micro Aerial Vehicle With Disturbance Observer.

PubMed

He, Wei; Yan, Zichen; Sun, Changyin; Chen, Yunan

2017-10-01

The research of this paper works out the attitude and position control of the flapping wing micro aerial vehicle (FWMAV). Neural network control with full state and output feedback are designed to deal with uncertainties in this complex nonlinear FWMAV dynamic system and enhance the system robustness. Meanwhile, we design disturbance observers which are exerted into the FWMAV system via feedforward loops to counteract the bad influence of disturbances. Then, a Lyapunov function is proposed to prove the closed-loop system stability and the semi-global uniform ultimate boundedness of all state variables. Finally, a series of simulation results indicate that proposed controllers can track desired trajectories well via selecting appropriate control gains. And the designed controllers possess potential applications in FWMAVs.

Why Do Kestrels Soar?

PubMed Central

Hernández-Pliego, Jesús; Rodríguez, Carlos; Bustamante, Javier

2015-01-01

Individuals allocate considerable amounts of energy to movement, which ultimately affects their ability to survive and reproduce. Birds fly by flapping their wings, which is dependent on the chemical energy produced by muscle work, or use soaring-gliding flight, in which chemical energy is replaced with energy harvested from moving air masses, such as thermals. Flapping flight requires more energy than soaring-gliding flight, and this difference in the use of energy increases with body mass. However, soaring-gliding results in lower speeds than flapping, especially for small species. Birds therefore face a trade-off between energy and time costs when deciding which flight strategy to use. Raptors are a group of large birds that typically soar. As relatively light weight raptors, falcons can either soar on weak thermals or fly by flapping with low energy costs. In this paper, we study the flight behavior of the insectivorous lesser kestrel (Falco naumanni) during foraging trips and the influence of solar radiation, which we have adopted as a proxy for thermal formation, on kestrel flight variables. We tracked 35 individuals from two colonies using high frequency GPS-dataloggers over four consecutive breeding seasons. Contrary to expectations, kestrels relied heavily on thermal soaring when foraging, especially during periods of high solar radiation. This produced a circadian pattern in the kestrel flight strategy that led to a spatial segregation of foraging areas. Kestrels flapped towards foraging areas close to the colony when thermals were not available. However, as soon as thermals were formed, they soared on them towards foraging areas far from the colony, especially when they were surrounded by poor foraging habitats. This reduced the chick provisioning rate at the colony. Given that lesser kestrels have a preference for feeding on large insects, and considering the average distance they cover to capture them during foraging trips, to commute using flapping flight would result in a negative energy balance for the family group. Our results show that lesser kestrels prioritize saving energy when foraging, suggesting that kestrels are more energy than time-constrained during the breeding season. PMID:26689780

Correlation between vortex structures and unsteady loads for flapping motion in hover

NASA Astrophysics Data System (ADS)

Jardin, Thierry; Chatellier, Ludovic; Farcy, Alain; David, Laurent

2009-10-01

During the past decade, efforts were made to develop a new generation of unmanned aircrafts, qualified as Micro-Air Vehicles. The particularity of these systems resides in their maximum dimension limited to 15 cm, which, in terms of aerodynamics, corresponds to low Reynolds number flows ( Re ≈ 102 to 104). At low Reynolds number, the concept of flapping wings seems to be an interesting alternative to the conventional fixed and rotary wings. Despite the fact that this concept may lead to enhanced lift forces and efficiency ratios, it allows hovering coupled with a low-noise generation. Previous studies (Dickinson et al. in Science 284:1954-1960, 1999) revealed that the flow engendered by flapping wings is highly vortical and unsteady, inducing significant temporal variations of the loads experienced by the airfoil. In order to enhance the aerodynamic performance of such flapping wings, it is essential to give further insight into the loads generating mechanisms by correlating the spatial and temporal evolution of the vortical structures together with the time-dependent lift and drag. In this paper, Time Resolved Particle Image Velocimetry is used as a basis to evaluate both unsteady forces and vortical structures generated by an airfoil undergoing complex motion (i.e. asymmetric flapping flight), through the momentum equation approach and a multidimensional wavelet-like vortex parameterization method, respectively. The momentum equation approach relies on the integration of flow variables inside and around a control volume surrounding the airfoil (Noca et al. in J Fluids Struct 11:345-350, 1997; Unal et al. in J Fluids Struct 11:965-971, 1997). Besides the direct link performed between the flow behavior and the force mechanisms, the load characterization is here non-intrusive and specifically convenient for flapping flight studies thanks to its low Reynolds flows’ sensitivity and adaptability to moving bodies. Results are supported by a vortex parameterization which evaluates the circulation of the multiple vortices generated in such complex flows. The temporal evolution of the loads matches the flow behavior and hence reveals the preponderant inertial force component and that due to vortical structures.

Propeller thoracodorsal artery perforator flap for breast reconstruction.

PubMed

Angrigiani, Claudio; Rancati, Alberto; Escudero, Ezequiel; Artero, Guillermo; Gercovich, Gustavo; Deza, Ernesto Gil

2014-08-01

The thoracodorsal artery perforator (TDAP) flap has been described for breast reconstruction. This flap requires intramuscular dissection of the pedicle. A modification of the conventional TDAP surgical technique for breast reconstruction is described, utilizing instead a propeller TDAP flap. The authors present their clinical experience with the propeller TDAP flap in breast reconstruction alone or in combination with expanders or permanent implants. From January 2009 to February 2013, sixteen patients had breast reconstruction utilizing a propeller TDAP flap. Retrospective analysis of patient characteristics, clinical indications, procedure and outcomes were performed. The follow-up period ranged from 4 to 48 months. Sixteen patients had breast reconstruction using a TDAP flap with or without simultaneous insertion of an expander or implant. All flaps survived, while two cases required minimal resection due to distal flap necrosis, healing by second intention. There were not donor-site seromas, while minimal wound dehiscence was detected in two cases. The propeller TDAP flap appears to be safe and effective for breast reconstruction, resulting in minimal donor site morbidity. The use of this propeller flap emerges as a true alternative to the traditional TDAP flap.

The Anterior Interosseus Artery Perforator Flap: Anatomical Dissections and Clinical Study

PubMed Central

Panse, Nikhil S; Joshi, Sheetal B; Sahasrabudhe, Parag B; Bahetee, B; Gurude, Pradnya; Chandanwale, Ajay

2017-01-01

BACKGROUND Reconstruction of upper extremity deformities continues to be a challenge to the reconstructive surgeon. Various loco regional, distant and free flaps are available for reconstruction. However, each has its own set of advantages and disadvantages. Of the commonly performed local flaps, radial artery forearm flap, and the posterior interosseus artery flap stand out prominently. Recently, perforator propeller flaps have been used for resurfacing the upper extremity. The anterior interosseus artery perforator flap is an uncommonly used and described flap. METHODS This study was divided into anatomical study and clinical application in a IV level of evidence. In the anatomical study, five upper extremities were studied. Clinically, 12 patients underwent reconstruction using the anterior interosseus artery perforator flap. Flaps were performed by a single surgeon. A retrospective review of these cases from November 2008 to May 2014 is presented. RESULTS The anterior interosseus artery perforator was identified in four out of five cadaver limbs. The septocutaneous perforator was in the fifth extensor compartment around 4 cm proximal to the wrist joint. Of the twelve flaps, there was complete necrosis in one flap, and partial necrosis in one flap. The patient with complete necrosis underwent skin grafting at a later date. The wound healed secondarily in case of partial flap necrosis. CONCLUSION Anterior interosseus artery perforator flap must be considered as an important reconstructive option in the armamentarium of the plastic surgeon, while managing hand and wrist defects. PMID:28713704

Facial artery musculomucosal flap for reconstruction of skull base defects: a cadaveric study.

PubMed

Xie, Liyue; Lavigne, François; Rahal, Akram; Moubayed, Sami Pierre; Ayad, Tareck

2013-08-01

Failure in skull base defects reconstruction following tumor resection can have serious consequences such as ascending meningitis and pneumocephaly. The nasoseptal flap showed a very low incidence of cerebrospinal fluid leak but is not always available. The superiorly pedicled facial artery musculomucosal (FAMM) flap has been successfully used for reconstruction of head and neck defects. Our objective is to show that the FAMM flap can be used as a new alternative in skull base reconstruction. Cadaveric study. Feasibility. Thirteen specimens underwent bilateral FAMM flap dissection. Two new modifications of the traditional FAMM flap have been developed. Feasibility in FAMM flap transfer to the skull base was investigated through endoscopic skull base dissection and maxillectomy in four specimens. Measurements were recorded for each harvested flap. The mean surface area of the modified FAMM flap efficient for reconstruction was 15.90 cm(2) . The flaps easily covered the simulated defects of the frontal sinus and the fovea ethmoidalis areas. Modifications of the traditional FAMM flap were necessary for a tension-free coverage of the planum sphenoidale and sella turcica. The FAMM flap holds high potential as a new alternative vascular flap in skull base reconstruction. However, it has not been used in patients yet and should be considered only when other options are not available. New modifications developed in this article can elongate the traditional FAMM flap, potentially contributing to a tighter seal of the skull base defect than FAMM flap alone. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

Reconstruction of Anterolateral Thigh Defects Using Perforator-Based Propeller Flaps.

PubMed

Iida, Takuya; Yoshimatsu, Hidehiko; Koshima, Isao

2017-10-01

Usually, anterolateral thigh (ALT) defects with width more than 8 cm cannot be closed directly. Although several methods of using local flaps exist, flap mobility of these methods is limited. We introduced a perforator-based propeller flap for such reconstruction. Their maximal mobility, which minimizes their size, is their greatest advantage. In addition, we present our technical refinements including double-axes propeller flap, the use of indocyanine green real-time angiography, and supercharged propeller flap for safer flap transfer. Seven patients underwent perforator-based propeller flap reconstruction of ALT defects. Flaps were designed cranial or caudal to the defect according to the perforator locations. To maximize mobility, flaps were designed so that the perforator was located at the periphery and closer to the defect. After rotating the flap to the defect, indocyanine green angiography was performed to determine the need for supercharge. In all cases, all flaps survived completely. Defect size ranged from 12 × 11 cm to 18 × 16 cm, and flap size ranged from 7 × 5 cm to 15 × 7 cm. The number of perforators in the flap was 1 in 3 cases and 2 in 4 cases. Supercharging was performed in 3 cases. Donor-site complications, including gait disturbance, were not observed. This method achieves ALT defect closure with minimal donor-site morbidity and can provide prompt and aesthetically acceptable results. Indocyanine green real-time angiography and supercharging technique are also useful for safer and reliable flap transfer.

Comparison of Dorsal Intercostal Artery Perforator Propeller Flaps and Bilateral Rotation Flaps in Reconstruction of Myelomeningocele Defects.

PubMed

Tenekeci, Goktekin; Basterzi, Yavuz; Unal, Sakir; Sari, Alper; Demir, Yavuz; Bagdatoglu, Celal; Tasdelen, Bahar

2018-04-09

Bilateral rotation flaps are considered the workhorse flaps in reconstruction of myelomeningocele defects. Since the introduction of perforator flaps in the field of reconstructive surgery, perforator flaps have been used increasingly in the reconstruction of various soft tissue defects all over the body because of their appreciated advantages. The aim of this study was to compare the complications and surgical outcomes between bilateral rotation flaps and dorsal intercostal artery perforator (DICAP) flaps in the soft tissue reconstruction of myelomeningocele defects. Between January 2005-February 2017, we studied 47 patients who underwent reconstruction of myelomeningocele defects. Patient demographics, operative data, and postoperative data were reviewed retrospectively and are included in the study. We found no statistically significant differences in patient demographics and surgical complications between these two groups; this may be due to small sample size. With regard to complications-partial flap necrosis, cerebrospinal fluid (CSF) leakage, necessity for reoperation, and wound infection-DICAP propeller flaps were clinically superior to rotation flaps. Partial flap necrosis was associated with CSF leakage and wound infection, and CSF leakage was associated with wound dehiscence. Although surgical outcomes obtained with DICAP propeller flaps were clinically superior to those obtained with rotation flaps, there was no statistically significant difference between the two patient groups. A well-designed comparative study with adequate sample size is needed. Nonetheless, we suggest using DICAP propeller flaps for reconstruction of large myelomeningocele defects.

Indocyanine green laser angiography improves deep inferior epigastric perforator flap outcomes following abdominal suction lipectomy.

PubMed

Casey, William J; Connolly, Katharine A; Nanda, Alisha; Rebecca, Alanna M; Perdikis, Galen; Smith, Anthony A

2015-03-01

The reliability of deep inferior epigastric artery perforator (DIEP) flap reconstruction following abdominal liposuction is controversial. The authors' early cases were technically successful; however, they experienced high partial flap loss and fat necrosis rates. The authors sought to compare DIEP flap outcomes in the setting of prior liposuction after the use of intraoperative indocyanine green angiography compared to when flaps were assessed on clinical grounds alone. A retrospective review of a consecutive series of DIEP flaps following liposuction at a single institution was performed, comparing those evaluated on clinical grounds alone and those in which indocyanine green angiography was used intraoperatively. Outcomes measured included anastomotic complications, total flap loss, partial flap loss, fat necrosis, and postoperative abdominal wounds. Thirteen DIEP flaps following prior liposuction were performed on 11 patients from July of 2003 through January of 2014. All patients had preoperative imaging with duplex ultrasound or computed tomographic angiography to analyze perforator suitability before surgical exploration. Seven flaps were evaluated intraoperatively on clinical grounds alone. Six flaps were assessed and modified based on indocyanine green angiography. All flaps were successful; however, partial flap loss and fat necrosis rates dropped from 71.4 percent to 0 percent when indocyanine green angiography was used intraoperatively (p = 0.02). Indocyanine green angiography is an excellent vascular imaging modality for intraoperative use to assess flap perfusion, and improves outcomes in DIEP flaps when harvested after prior abdominal suction lipectomy.

The changing role of pectoralis major flap in head and neck reconstruction.

PubMed

Liu, Hin-Lun; Chan, Jimmy Yu-Wai; Wei, William Ignace

2010-11-01

Although pectoralis major flap (PM flap) has been used as the workhorse flap in head and neck reconstruction, its use in head and neck defects seems to fall out of favour in the era of free tissue transfer. The aim of this review is to find out the role of PM flap in modern head and neck surgery. Medical records of patients who underwent PM flap reconstruction for head and neck defect in our division were reviewed. The age, gender, flap type, indication and complication rate were described. Between January 1998 and December 2008, 202 PM flaps were used for head and neck reconstruction in 192 patients. In the early study period (1998-June 2003), out of the 119 PM flap reconstructions, 106 (89%) were performed for immediate reconstruction after resection of head and neck tumour, while 10 (8%) were performed as salvage procedures for complication after tumour resection e.g. failure of free flap, pharyngocutaneous fistula. In the late study period (July 2003-2008), out of the 83 PM flap reconstructions, 58 (70%) were performed for immediate reconstruction, while 24 (29%) were performed as salvage procedures. For immediate reconstruction after tumour extirpation, 51 flaps (48%) were performed for reconstruction of the tongue in the early study period, while only 14 (24%) were performed in the late study period. The number of PM flap used for immediate reconstruction for other head and neck defects remained relatively static throughout the two study periods. Over the study period, there were 10 (5%) cases of partial flap necrosis and 2 (1%) total flap loss, making the overall flap necrosis rate 6%. In the era of free tissue transfer, the role of PM flap in head and neck surgery has shifted from immediate reconstruction to salvage operation. However, PM flap still has an unique role in the repair of certain head and neck defects.

Tensor fascia lata flap versus tensor fascia lata perforator-based island flap for the coverage of extensive trochanteric pressure sores.

PubMed

Kim, Youn Hwan; Kim, Sang Wha; Kim, Jeong Tae; Kim, Chang Yeon

2013-06-01

Tensor fascia lata (TFL) musculocutaneous flaps often require a donor site graft when harvesting a large flap. However, a major drawback is that it also sacrifices the muscle. To overcome this disadvantage, we designed a TFL perforator-based island flap that was harvested from a site near the defect and involved transposition within 90 degrees without full isolation of the pedicles. We performed procedures on 17 musculocutaneous flaps and 23 perforator-based island flaps, and compared the outcomes of these surgeries. The overall complication rate was 27.5% (11 regions). There were 7 complications related to the musculocutaneous flaps and 4 complications related to the perforator flaps. Although there were no statistical differences between those groups, lower complication rates were associated with procedures involving perforator flaps. The TFL perforator procedure is a simple and fast operation that avoids sacrificing muscle. This decreases complication rates compared to true perforator flap techniques that require dissection around the perforator or pedicle.

Propeller Flap for Complex Distal Leg Reconstruction: A Versatile Alternative when Reverse Sural Artery Flap is Not Feasible.

PubMed

Ademola, Samuel A; Michael, Afieharo I; Oladeji, Femi J; Mbaya, Kefas M; Oyewole, O

2015-01-01

Reverse sural artery fasciocutaneous flap has become a workhorse for the reconstruction of distal leg soft tissue defects. When its use is not feasible, perforator-based propeller flap offers a better, easier, faster, and cheaper alternative to free flap. We present our experience with two men both aged 34 years who sustained Gustilo 3B injuries from gunshot. The donor area for reversed sural artery flap was involved in the injuries. They had early debridement, external fixation, and wound coverage with perforator-based propeller flaps. The donor sites were covered with skin graft. All flaps survived. There were minor wound edge ulcers due to the pressure of positioning that did not affect flap survival and the ulcers healed with conservative management. Perforator-based propeller flap is a versatile armamentarium for reconstruction of soft tissue defects of the distal leg in resource-constrained settings, especially when the donor area for a reverse flow sural flap artery is involved in the injury.

The Arterialized Facial Artery Musculo-Mucosal Island Flap for Post-Oncological Tongue Reconstruction.

PubMed

Moro, Alessandro; Saponaro, Gianmarco; Doneddu, Piero; Cervelli, Daniele; Pelo, Sandro; Gasparini, Giulio; Garagiola, Umberto; D'Amato, Giuseppe; Todaro, Mattia

2018-05-15

In 1992, Pribaz described the facial artery musculomucosal flap (FAMM), an axial musculomucosal flap based on the facial artery. The FAMM flap, a modification of the nasolabial and buccal mucosal flaps, is widely used in the reconstruction of defects in the oral cavity. Many modifications of this flap have been described in the literature. Here we aimed to explore the use of an arterialized tunnelized FAMM island flap (a-FAMMIF) for the reconstruction tongue defects after tumor resection. From January 2015 to December 2016, five cases of tongue cancer were selected for the use of arterialized FAMMIF flap to reconstruct defects after tumor resection. Reconstruction was successful in all cases, except one case of total flap necrosis; partial necrosis of the flap occurred in two patients, which were solved with medications. The authors consider the a-FAMMIF an unreliable flap in the reconstruction of tongue defects.The authors recommend avoiding tunneling and island modification when the vein is not included in the pedicle.

Piloted simulation study of two tilt-wing flap control concepts, phase 2

NASA Technical Reports Server (NTRS)

Birckelbaw, Lourdes G.; Corliss, Lloyd D.; Hindson, William S.; Churchill, Gary B.

1994-01-01

A two phase piloted simulation study has been conducted in the Ames Vertical Motion Simulator to investigate alternative wing and flap controls for tilt-wing aircraft. This report documents the flying qualities results and findings of the second phase of the piloted simulation study and describes the simulated tilt-wing aircraft, the flap control concepts, the experiment design and the evaluation tasks. The initial phase of the study compared the flying qualities of both a conventional programmed flap and an innovative geared flap. The second phase of the study introduced an alternate method of pilot control for the geared flap and further studied the flying qualities of the programmed flap and two geared flap configurations. In general, the pilot ratings showed little variation between the programmed flap and the geared flap control concepts. Some differences between the two control concepts were noticed and are discussed in this report. The geared flap configurations had very similar results. Although the geared flap concept has the potential to reduce or eliminate the pitch control power requirements from a tail rotor or a tail thruster at low speeds and in hover, the results did not show reduced tail thruster pitch control power usage with the geared flap configurations compared to the programmed flap configuration. The addition of pitch attitude stabilization in the second phase of simulation study greatly enhanced the aircraft flying qualities compared to the first phase.

Free flap reconstruction for diabetic foot limb salvage.

PubMed

Sato, Tomoya; Yana, Yuichiro; Ichioka, Shigeru

2017-12-01

Although free flap is gaining popularity for the reconstruction of diabetic foot ulcers, it is unclear whether free flap reconstruction increases the chances of postoperative independent ambulation. The aim of this study is to evaluate the relationship between free flap success and postoperative ambulation. This study reviewed 23 cases of free flap reconstruction for diabetic foot ulcers between January 2007 and March 2014. Free rectus abdominis, latissimus dorsi, and anterolateral thigh flaps were used in ten, eight, and five patients, respectively. A comparison was made between free flap success and postoperative independent ambulation using Fisher's exact test. Two patients developed congestive heart failure with fatal consequences within 14 days postoperatively, resulting in an in-hospital mortality rate of 8.7%. Five patients lost their flaps (21.7%). Of the 16 patients who had flap success, 12 achieved independent ambulation. Five patients with flap loss did not achieve independent ambulation, except one patient who underwent secondary flap reconstruction using a distally based sural flap. Fisher's exact test revealed that independent ambulation was associated with free flap success (p = 0.047). The present study indicates that free flap reconstruction may increase the possibility of independent ambulation for patients with extensive tissue defects due to diabetic ulcers. Intermediate limb salvage rates and independent ambulation rates were favourable in patients with successful reconstruction. The use of foot orthoses and a team approach with pedorthists were effective to prevent recurrence.

Pedicled Temporalis Muscle Flap for Craniofacial Reconstruction: A 35-Year Clinical Experience with 366 Flaps.

PubMed

Spanio di Spilimbergo, Stefano; Nordera, Paolo; Mardini, Samir; Castiglione, Giusy; Chim, Harvey; Pinna, Vittore; Brunello, Massimo; Cusino, Claudio; Roberto, Squaquara; Baciliero, Ugo

2017-02-01

In the past 130 years, the temporalis muscle flap has been used for a variety of different indications. In this age of microsurgery and perforator flaps, the temporalis muscle flap still has many useful applications for craniofacial reconstruction. Three hundred sixty-six temporalis muscle flaps were performed in a single center between 1978 and 2012. The authors divided the cases into two series-before and after 1994-because, after 1994, they started to perform free flap reconstructions, and indications for reconstruction with a temporalis muscle flap were changed RESULTS:: In the series after 1994, flaps were most commonly used for reconstruction of defects in the maxilla, mandible, and oropharynx, in addition to facial reanimation and filling of orbital defects. Complications included total flap necrosis (1.6 percent) and partial flap necrosis (10.7 percent). The rate of material extrusion at the donor site decreased after porous polyethylene was uniformly used for reconstruction from 17.1 to 7.9 percent. The pedicled temporalis muscle flap continues to have many applications in craniofacial reconstruction. With increasing use of free flaps, the authors' indications for the pedicled temporalis muscle flap are now restricted to (1) orbital filling for congenital or acquired anophthalmia; (2) filling of unilateral maxillectomy defects; and (3) facial reanimation in selected cases of facial nerve palsy. Therapeutic, IV.

The versatile use of revisited de-epithelialization concept in superficial circumflex iliac and anterolateral thigh perforator free flap for head and neck reconstructions.

PubMed

Choi, Jong Woo; Kim, Young Chul; Oh, Tae Suk; Koh, Kyung S; Jeong, Woo Shik

2017-06-01

Although the perforator free flap is now a standard choice for head and neck reconstruction, problems such as microvascular complications, insufficient volume support for the defect, and fistula formation occur. We revisited a de-epithelialized concept for superficial circumflex iliac artery and anterolateral thigh perforator free flap to overcome these problems. We applied the de-epithelized perforator free flaps in 35 cases among 761 microsurgical head and neck reconstructions and investigated flap characteristics (length gain of pedicle, flap size, and volumetric analysis) and outcomes (flap failure, partial flap necrosis, hematoma, infection, and fistula). Satisfactory results were achieved regarding flap survival, volumetric compensation, and fistula formation. Flaps were transferred successfully in all patients, although 1 patient underwent revisional operation due to venous congestion. Transferred flap volume was significantly higher than the resected tumor volume (p < 0.01), which suggests volume augmentation in the destroyed neck envelope and a protective role against adjuvant radiation. Minor dehiscence and bleeding were seen in two cases, and no other complications were identified. The de-epithelialization concept for perforator free flap is helpful to overcome obstacles related to traditional free flaps in terms of flap survival and volumetric augmentation in head and neck reconstructions. Copyright © 2017 European Association for Cranio-Maxillo-Facial Surgery. Published by Elsevier Ltd. All rights reserved.

Can angiogenesis induced by chronic electrical stimulation enhance latissimus dorsi muscle flap survival for application in cardiomyoplasty?

PubMed

Overgoor, Max L E; Carroll, Sean M; Papanicolau, George; Carroll, Camilla M A; Ustüner, Tuncay E T; Stremel, Richard W; Anderson, Gary L; Franken, Ralph J P M; Kon, Moshe; Barker, John H

2003-01-01

In cardiomyoplasty, the latissimus dorsi muscle is lifted on its primary neurovascular pedicle and wrapped around a failing heart. After 2 weeks, it is trained for 6 weeks using chronic electrical stimulation, which transforms the latissimus dorsi muscle into a fatigue-resistant muscle that can contract in synchrony with the beating heart without tiring. In over 600 cardiomyoplasty procedures performed clinically to date, the outcomes have varied. Given the data obtained in animal experiments, the authors believe these variable outcomes are attributable to distal latissimus dorsi muscle flap necrosis. The aim of the present study was to investigate whether the chronic electrical stimulation training used to transform the latissimus dorsi muscle into fatigue-resistant muscle could also be used to induce angiogenesis, increase perfusion, and thus protect the latissimus dorsi muscle flap from distal necrosis. After 14 days of chronic electrical stimulation (10 Hz, 330 microsec, 4 to 6 V continuous, 8 hours/day) of the right or left latissimus dorsi muscle (randomly selected) in 11 rats, both latissimus dorsi muscles were lifted on their thoracodorsal pedicles and returned to their anatomical beds. Four days later, the resulting amount of distal flap necrosis was measured. Also, at predetermined time intervals throughout the experiment, muscle surface blood perfusion was measured using scanning laser Doppler flowmetry. Finally, latissimus dorsi muscles were excised in four additional stimulated rats, to measure angiogenesis (capillary-to-fiber ratio), fiber type (oxidative or glycolytic), and fiber size using histologic specimens. The authors found that chronic electrical stimulation (1) significantly (p < 0.05) increased angiogenesis (mean capillary-to-fiber ratio) by 82 percent and blood perfusion by 36 percent; (2) did not reduce the amount of distal flap necrosis compared with nonchronic electrical stimulation controls (29 +/- 5.3 percent versus 26.6 +/- 5.1 percent); (3) completely transformed the normally mixed (oxidative and glycolytic) fiber type distribution into all oxidative fibers; and (4) reduced fiber size in the proximal and middle but not in the distal segments of the flap. Despite the significant increase in angiogenesis and blood perfusion, distal latissimus dorsi muscle flap necrosis did not decrease. This might be because of three reasons: first, the change in muscle metabolism from anaerobic to aerobic may have rendered the muscle fibers more susceptible to ischemia. Second, because of the larger diameter of the distal fibers in normal and stimulated latissimus dorsi muscle, the diffusion distance for oxygen to the center of the distal fibers is increased, making fiber survival more difficult. Third, even though angiogenesis was significantly increased in the flap, cutting all but the single vascular pedicle resulted in the newly formed capillaries not receiving enough blood to provide nourishment to the distal latissimus dorsi muscle. The authors' findings indicate that chronic electrical stimulation as tested in these experiments could not be used to prevent distal latissimus dorsi muscle flap ischemia and necrosis in cardiomyoplasty.

[COMPARISON OF REPAIR EFFECT BETWEEN CHIMERIC ANTEROLATERAL THIGH FLAP AND SERIES-WOUND FLAPS FOR DEFECT AFTER RESECTION OF ORAL AND MAXILLOFACIAL CANCER].

PubMed

Yang, Heping; Zhang, Hongwu; Chen, Haidi; Yang, Shuxiong; Wang, Jun; Hu, Dawang

2016-04-01

To compare the effectiveness of complex defects repair between using chimeric anterolateral thigh flap and series-wound flaps after resection of oral and maxillofacial cancer. After resection of oral and maxillofacial cancer, defect was repaired with chimeric anterolateral thigh flap in 39 patients between January 2011 and July 2014 (chimeric anterolateral thigh flap group); and defect was repaired with series-wound flaps in 35 patients between January 2009 and December 2010 (series-wound flaps group). There was no significant difference in gender, age, duration of disease, tumor type, tumor staging, defect location, and defect area between 2 groups (P > 0.05). The operation time, flap harvesting and microvascular anastomosis time, stomach tube extraction time, and oral feeding time were recorded and compared between 2 groups, and postoperative complications were observed; the effectiveness was evaluated according to clinical efficacy evaluation table of bone and soft tissue defects reconstruction surgery in oral and maxillofacial region. Vascular crisis occurred in 2 cases of chimeric anterolateral thigh flap group, and 4 cases of series-wound flaps group. Partial necrosis appeared at distal end of a series-wound flaps, and oral fistula and infection developed in 3 series-wound flaps. The other flaps and the grafted skin at donor site survived; wounds at recipient site healed by first intention. The operation time, stomach tube extraction time, and oral feeding time of chimeric anterolateral thigh flap group were significantly shorter than those of series-wound flaps group (P < 0.05), while the flap harvesting and microvascular anastomosis time was significantly longer than that of series-wound flaps group (P < 0.05). The patients were followed up 1-5 years (mean, 2.5 years). At 3 months after operation, the appearance, patients' satisfaction, working conditions, oral closure function, chew, language performance, and swallowing scores of the chimeric anterolateral thigh-flap group were significantly better than those of the series-wound flaps group (P < 0.05), while there was no significant difference in diet, mouth opening degree, oral cavity holding water test, and occlusion scores between the 2 groups (P > 0.05). Using chimeric anterolateral thigh flap for defect repair after resection of oral and maxillofacial cancer can significantly shorten the operation time, accelerate postoperative rehabilitation, and help the functional recovery of oral closure, chewing, language performance, swallowing function when compared with the series-wound flaps.

The midline central artery forehead flap: a valid alternative to supratrochlear-based forehead flaps.

PubMed

Faris, Callum; van der Eerden, Paul; Vuyk, Hade

2015-01-01

This study clarifies the pedicle geometry and vascular supply of a midline forehead flap for nasal reconstruction. It reports on the vascular reliability of this flap and its ability to reduce hair transposition to the nose, a major complicating factor of previous forehead flap designs. To compare the vascular reliability of 3 different pedicle designs of the forehead flap in nasal reconstruction (classic paramedian, glabellar paramedian, and central artery flap design) and evaluate hair transposition rates and aesthetic results. Retrospective analysis of patient data and outcomes retrieved from computer files generated at the time of surgery, supplemented by data from the patient medical records and photographic documentation, from a tertiary referral nasal reconstructive practice, within a secondary-care hospital setting. The study population included all consecutive patients over a 19-year period who underwent primary forehead flap repair of nasal defects, with more than 3 months of postoperative follow-up and photographic documentation. Three sequential forehead flap patterns were used (classic paramedian flap, glabella flap, and central artery flap) for nasal reconstruction over the study duration. Data collected included patient characteristics, method of repair, complications, functional outcome, and patient satisfaction score. For cosmetic outcome, photographic documentation was scored by a medical juror. No forehead flap had vascular compromise in the first stage. Partial flap necrosis was reported in subsequent stages in 4 patients (1%), with no statistical difference in the rate of vascular compromise between the 3 flap designs. Hair transposition to the nose was lower in the central artery forehead flap (7%) compared with the classic paramedian (23%) and glabellar paramedian (13%) flaps (P < .05). Photographic evaluation in 227 patients showed that brow position (98%) and color match (83%) were good in the majority of the patients. In this series, the central artery forehead flap was as reliable (in terms of vascularity) as the glabellar and classic paramedian forehead flap. Its use resulted in a statistically significant reduction in transfer of hair to the nose in our series. 3.

The sensate free superior gluteal artery perforator (S-GAP) flap: a valuable alternative in autologous breast reconstruction.

PubMed

Blondeel, P N

1999-04-01

The superior and inferior myocutaneous gluteal free flaps have been considered as valuable alternatives to the latissimus dorsi or TRAM flap since 1975. The superior gluteal artery perforator (S-GAP) flap is the ultimate refinement of this myocutaneous flap as no gluteus maximus muscle is harvested. The flap is vascularised by one single perforator originating from the superior gluteal artery. This study summarises the prospectively gathered data on 20 free S-GAP flaps used for breast reconstruction in 16 patients. Immediate reconstruction was performed in six breasts and delayed in 14 breasts. Mean follow-up was 11.1 months. Two risk factors, Raynaud's disease and radiotherapy, were the cause of flap revision in two different patients. Total flap loss occurred in one case. Partial flap loss was not observed and a small area of fat necrosis was diagnosed by mammography in one other patient. All flaps were anastomosed to the internal mammary vessels at the 3rd costochondral junction. The anatomy of the sensate nerves of the S-GAP flap is described. Two nervous repairs provided early sensory recovery. The free S-GAP flap has become my personal second choice for autologous breast reconstruction after the DIEP (deep inferior epigastric perforator) flap. The S-GAP flap is indicated in patients with an asthenic body habitus or with excessive abdominal scarring. The advantages are the abundance of adipose tissue in this area even in thin patients, a long vascular pedicle, a hidden scar, improved projection of the reconstructed breast compared to the DIEP and TRAM flaps and the preservation of the entire gluteus maximus muscle. The donor morbidity is extremely low.

Perforator Propeller Flap for Oncologic Reconstruction of Soft Tissue Defects in Trunk and Extremities.

PubMed

Yu, Shengji; Zang, Mengqing; Xu, Libin; Zhao, Zhenguo; Zhang, Xinxin; Zhu, Shan; Chen, Bo; Ding, Qiang; Liu, Yuanbo

2016-10-01

Defects after soft tissue sarcoma resection are usually managed by myocutaneous flaps or free flaps. However, harvesting muscle will cause functional morbidities, and some regions lack reliable recipient vessel. Our purpose is to use various perforator propeller flaps for oncologic reconstruction. Between 2008 and 2014, 33 perforator propeller flaps were performed in 24 patients to reconstruct the defects after tumor resection in trunk and extremities. Fifteen patients underwent tumor resection previously. Thirteen patients underwent adjuvant radiotherapy or chemotherapy. Flaps based on perforators adjacent to the lesions were raised and rotated in propeller fashion to repair the defects. Twenty-seven flaps were based on perforators of known source vessels, and 6 were harvested in freestyle fashion. The defects were repaired with 2 flaps in 4 patients and 3 flaps in 2 patients. The mean skin paddle dimension was 8.36 cm in width and 20.42 cm in length. The mean degree of flap rotation was 158.79°. Complications include partial necrosis of 6 flaps in 5 cases and venous congestion of 1 flap. In these 6 patients, 3 underwent adjuvant radiotherapy. The donor sites were primarily closed in 21 patients and skin grafted in 3 patients. No functional loss related to flap harvesting was recognized. The perforator propeller flaps can be used to manage the medium defects in extremities and large defects in torso after soft tissue sarcoma resection. They avoid the sacrifice of the underlying muscle and eliminate the concerns of the unavailability of recipient vessels. The perforator propeller flaps provide flexible options for versatile oncologic reconstruction in trunk and extremities. However, the impact of radiotherapy on the viability of the flaps for local reconstruction needs further investigation.

Rate-determining Step of Flap Endonuclease 1 (FEN1) Reflects a Kinetic Bias against Long Flaps and Trinucleotide Repeat Sequences.

PubMed

Tarantino, Mary E; Bilotti, Katharina; Huang, Ji; Delaney, Sarah

2015-08-21

Flap endonuclease 1 (FEN1) is a structure-specific nuclease responsible for removing 5'-flaps formed during Okazaki fragment maturation and long patch base excision repair. In this work, we use rapid quench flow techniques to examine the rates of 5'-flap removal on DNA substrates of varying length and sequence. Of particular interest are flaps containing trinucleotide repeats (TNR), which have been proposed to affect FEN1 activity and cause genetic instability. We report that FEN1 processes substrates containing flaps of 30 nucleotides or fewer at comparable single-turnover rates. However, for flaps longer than 30 nucleotides, FEN1 kinetically discriminates substrates based on flap length and flap sequence. In particular, FEN1 removes flaps containing TNR sequences at a rate slower than mixed sequence flaps of the same length. Furthermore, multiple-turnover kinetic analysis reveals that the rate-determining step of FEN1 switches as a function of flap length from product release to chemistry (or a step prior to chemistry). These results provide a kinetic perspective on the role of FEN1 in DNA replication and repair and contribute to our understanding of FEN1 in mediating genetic instability of TNR sequences. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Pedicled Extranasal Flaps in Skull Base Reconstruction

PubMed Central

Kim, Grace G.; Hang, Anna X.; Mitchell, Candace; Zanation, Adam M.

2013-01-01

Cerebrospinal fluid (CSF) leaks most commonly arise during or after skull base surgery, although they occasionally present spontaneously. Recent advances in the repair of CSF leaks have enabled endoscopic endonasal surgery to become the preferred option for management of skull base pathology. Small defects (<1cm) can be repaired by multilayered free grafts. For large defects (>3cm), pedicled vascular flaps are the repair method of choice, resulting in much lower rates of postoperative CSF leaks. The pedicled nasoseptal flap (NSF) constitutes the primary reconstructive option for the vast majority of skull base defects. It has a large area of potential coverage and high rates of success. However, preoperative planning is required to avoid sacrificing the NSF during resection. In cases where the NSF is unavailable, often due to tumor involvement of the septum or previous resection removing or compromising the flap, other flaps may be considered. These flaps include intranasal options—inferior turbinate (IT) or middle turbinate (MT) flaps—as well as regional pedicled flaps: pericranial flap (PCF), temporoparietal fascial flap (TPFF), or palatal flap (PF). More recently, novel alternatives such as the pedicled facial buccinator flap (FAB) and the pedicled occipital galeopericranial flap (OGP) have been added to the arsenal of options for skull base reconstruction. Characteristics of and appropriate uses for each flap are described. PMID:23257554

Investigation of leading-edge flap performance on delta and double-delta wings at supersonic speeds

NASA Technical Reports Server (NTRS)

Covell, Peter F.; Wood, Richard M.; Miller, David S.

1987-01-01

An investigation of the aerodynamic performance of leading-edge flaps on three clipped delta and three clipped double-delta wing planforms with aspect ratios of 1.75, 2.11, and 2.50 was conducted in the Langley Unitary Plan Wind Tunnel at Mach numbers of 1.60, 1.90, and 2.16. A primary set of fullspan leading-edge flaps with similar root and tip chords were investigated on each wing, and several alternate flap planforms were investigated on the aspect-ratio-1.75 wings. All leading-edge flap geometries were effective in reducing the drag at lifting conditions over the range of wing aspect ratios and Mach numbers tested. Application of a primary flap resulted in better flap performance with the double-delta planform than with the delta planform. The primary flap geometry generally yielded better performance than the alternate flap geometries tested. Trim drag due to flap-induced pitching moments was found to reduce the leading-edge flap performance more for the delta planform than for the double-delta planform. Flow-visualization techniques showed that leading-edge flap deflection reduces crossflow shock-induced separation effects. Finally, it was found that modified linear theory consistently predicts only the effects of leading-edge flap deflection as related to pitching moment and lift trends.

Mandibular reconstruction in irradiated patients utilizing myosseous-cutaneous flaps

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pearlman, N.W.; Albin, R.E.; O'Donnell, R.S.

1983-10-01

Myosseous-cutaneous flaps were used for mandibular reconstruction in 16 irradiated patients. Three of six sternomastoid-clavicle flaps failed (all in conjunction with a neck dissection), as did one of 10 pectoralis major-anterior-fifth rib flaps. One trapezius-scapular flap was used and it succeeded. We found the blood supply of the sternomastoid-clavicle flap too tenuous for use in conjunction with a neck dissection. The trapezius-scapular flap had too short an arc of rotation to be used for defects other than those in the horizontal ramus. In addition, this flap required a change of position and created an undesirable functional deformity. The pectoralis major-fifthmore » rib flap, in contrast, could be used for a variety of defects, in conjunction with a neck dissection, and did not require a change of position during operation. We found it to be the most versatile and dependable of the flaps employed in this series.« less

Predictors of Salivary Fistulas in Patients Undergoing Salvage Total Laryngectomy

PubMed Central

Wang, Steven J.

2014-01-01

Background. Salivary fistula is a common complication after salvage total laryngectomy. Previous studies have not considered the number of layers of pharyngeal closure and have not classified fistulas according to severity. Our objective was to analyze our institutional experience with salvage total laryngectomy, categorize salivary fistulas based on severity, and study the effect of various pharyngeal closure techniques on fistula incidence. Methods. Retrospective analysis of 48 patients who underwent salvage total laryngectomy, comparing pharyngeal closure technique and use of a pectoralis major flap with regard to salivary fistula rate. Fistulas were categorized into major and minor fistulas based on whether operative intervention was required. Results. The major fistula rate was 18.8% (9/48) and the minor fistula rate was 29.2% (14/48). The overall (major plus minor) fistula rate was 47.9%. The overall fistula and major fistula rates decreased with increasing the number of closure layers and with use of a pectoralis major flap; however, these correlations did not reach statistical significance. Other than age, there were no clinicopathologic variables associated with salivary fistulas. Conclusion. For salvage total laryngectomies, increasing the number of closure layers or use of a pectoralis major flap may reduce the risk of salivary fistula. PMID:27355065

Changes in oxidation state of chromium during LDEF exposure

NASA Technical Reports Server (NTRS)

Golden, Johnny L.

1992-01-01

The solar collector used for the McDonnell-Douglas Cascade Variable Heat Pipe, Experiment A0076 (Michael Grote - Principal Investigator) was finished with black chromium plating as a thermal control coating. The coating is metallic for low emittance, and is finely microcrystalline to a dimension which yields its high absorptivity. An underplate of nickel was applied to the aluminum absorber plate in order to achieve optimal absorptance characteristics from the black chromium plate surface. Experiment A0076 was located at tray position F9, receiving a projected 8.7 x 10 exp 21 atomic oxygen atoms/sq cm and 11,200 ESH solar radiation. During retrieval, it was observed that the aluminized kapton thermal blankets covering most of the tray were severely eroded by atomic oxygen, and that a 'flap' of aluminum foil was overlaying a roughly triangular shaped portion of the absorber panel. The aluminum foil 'flap' was lost sometime between the Long Duration Exposure Facility (LDEF) retrieval and deintegration. At deintegration, the black chromium was observed to have discolored where it had been covered by the foil 'flap'. A summary of the investigation into the cause of the discoloration is presented.

Tensile properties of nicalon fiber-reinforced carbon following aerospace turbine engine testing

NASA Astrophysics Data System (ADS)

Pierce, J. L.; Zawada, L. P.; Srinivasan, R.

2003-06-01

The durability of coated Nicalon silicon carbide fiber-reinforced carbon (SiC/C) as the flap and seal exhaust nozzle components in a military aerospace turbine engine was studied. Test specimens machined from both a flap and a seal component were tested for residual strength following extended ground engine testing on a General Electric F414 afterburning turbofan engine. Although small amounts of damage to the protective exterior coating were identified on each component following engine testing, the tensile strengths were equal to the as-fabricated tensile strength of the material. Differences in strength between the two components and variability within the data sets could be traced back to the fabrication process using witness coupon test data from the manufacturer. It was also observed that test specimens machined transversely across the flap and seal components were stronger than those machined along the length. The excellent retained strength of the coated SiC/C material after extended exposure to the severe environment in the afterburner exhaust section of an aerospace turbofan engine has resulted in this material being selected as the baseline material for the F414 exhaust nozzle system.

A lining vomer flap for palate pushback in unilateral cleft palate repair.

PubMed

Clavin, H D; Owsley, J Q

1978-01-01

A combinaation vomer mucoperiosteal flap and nasal floor mucoperiosteal flap is described which is used to achieve nasal coverage in unilateral cleft palate patients requiring pushbacks. A posteriorly based readily accessible vomer flap is raised on the cleft side and used as nasal lining for the palatal mucoperiosteal flap on the non-cleft side. On the cleft side, a symmetrically sized nasal floor flap is easily elevated under direct vision and used to cover the nasal aspect of the corresponding mucoperiosteal palatal flap.

The role of postoperative hematoma on free flap compromise.

PubMed

Ahmad, Faisal I; Gerecci, Deniz; Gonzalez, Javier D; Peck, Jessica J; Wax, Mark K

2015-08-01

Hematomas may develop in the postoperative setting after free tissue transfer. When hematomas occur, they can exert pressure on surrounding tissues. Their effect on the vascular pedicle of a free flap is unknown. We describe our incidence of hematoma in free flaps and outcomes when the flap is compromised. Retrospective chart review of 1,883 free flaps performed between July 1998 and June 2014 at a tertiary referral center. Patients with free flap compromise due to hematoma were identified. Etiology, demographic data, and outcomes were evaluated. Eighty-eight (4.7%) patients developed hematomas. Twenty (22.7%) of those had flap compromise. Twelve compromises (60%) showed evidence of pedicle thrombosis. The salvage rate was 75% versus 54% in 79 flaps with compromise from other causes (P = .12). Mean time to detection of the hematoma was 35.3 hours in salvaged flaps compared to 91.6 hours in unsalvageable flaps (P = .057). Time to operating room (OR) from detection was 2.8 hours in salvageable flaps compared to 12.4 hours in nonsalvageable flaps (P = .053). The salvage rate for flaps that returned to the OR in <5 hours was 93.3% compared to 20% (P = .0049) for those that did not. Vascular thrombosis reduced salvage rate to 58.3% from 100% (P = .002) when there was no thrombosis. In our series hematomas developed rarely. When they did, 23% went on to develop flap compromise. Prompt recognition and re-exploration allowed for a high salvage rate. Vessel thrombosis predicted inability to salvage the flap. 4 © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

The trapezius perforator flap: an underused but versatile option in the reconstruction of local and distant soft-tissue defects.

PubMed

Sadigh, Parviz L; Chang, Li-Ren; Hsieh, Ching-Hua; Feng, Wen-Jui; Jeng, Seng-Feng

2014-09-01

The trapezius myocutaneous flap is an established reconstructive option in head and neck cases The authors present their experience with 10 trapezius perforator flaps, all raised using a freestyle technique of perforator dissection, to successfully reconstruct both local and distant soft-tissue defects. Ten patients underwent soft-tissue reconstruction using trapezius perforator flaps. After mapping the perforator with a handheld Doppler device at the intersection of a horizontal line drawn 6 to 8 cm inferior to the scapular spine and a vertical line drawn 8 to 9 cm lateral to the midline of the back, perforator flaps were raised in a freestyle fashion, with complete preservation of the trapezius muscle. The flap can be pedicled into local defects or transferred as a free flap. Six flaps were elevated as pedicled flaps and four were transferred as free flaps. Flap size ranged from 6 × 4 cm to 25 × 15 cm. The pedicle length ranged from 4 to 14 cm. The pedicle originated from the dorsal scapular artery. In one case, the authors converted from a pedicled flap to a free flap secondary to insufficient pedicle length. All donor sites were closed directly. The follow-up period ranged from 4 months to 4 years. All of the flaps survived completely with no major complications, and no patients developed any shoulder dysfunction. The trapezius perforator flap is a reliable and versatile reconstructive option that can be used to repair both local and distant soft-tissue defects. The donor-site morbidity is minimal. Therapeutic, IV.

Comparison of gluteal perforator flaps and gluteal fasciocutaneous rotation flaps for reconstruction of sacral pressure sores.

PubMed

Chen, Yen-Chou; Huang, Eng-Yen; Lin, Pao-Yuan

2014-03-01

The gluteus maximus myocutaneous flap was considered the workhorse that reconstructed sacral pressure sores, but was gradually replaced by fasciocutaneous flap because of several disadvantages. With the advent of the perforator flap technique, gluteal perforator (GP) flap has gained popularity nowadays. The aim of this study was to compare the complications and outcomes between GP flaps and gluteal fasciocutaneous rotation (FR) flaps in the treatment of sacral pressure sores. Between April 2007 and June 2012, 63 patients underwent sacral pressure sore reconstructions, with a GP flap used in 31 cases and an FR flap used in 32 cases. Data collected on the patients included patient age, gender, co-morbidity for being bedridden and follow-up time. Surgical details collected included the defect size, operative time and estimated blood loss. Complications recorded included re-operation, dehiscence, flap necrosis, wound infection, sinus formation, donor-site morbidity and recurrence. The complications and clinical outcomes were compared between these two groups. We found that there was no significant difference in patient demographics, surgical complications and recurrence between these two groups. In gluteal FR flap group, all recurrent cases (five) were treated by reuse of previous flaps. Both methods are comparable, good and safe in treating sacral pressure sores. Gluteal FR flap can be performed without microsurgical dissection, and re-rotation is feasible in recurrent cases. The authors suggest using gluteal FR flaps in patients with a high risk of sore recurrence. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Free Flap Reconstruction Monitoring Techniques and Frequency in the Era of Restricted Resident Work Hours.

PubMed

Patel, Urjeet A; Hernandez, David; Shnayder, Yelizaveta; Wax, Mark K; Hanasono, Matthew M; Hornig, Joshua; Ghanem, Tamer A; Old, Matthew; Jackson, Ryan S; Ledgerwood, Levi G; Pipkorn, Patrik; Lin, Lawrence; Ong, Adrian; Greene, Joshua B; Bekeny, James; Yiu, Yin; Noureldine, Salem; Li, David X; Fontanarosa, Joel; Greenbaum, Evan; Richmon, Jeremy D

2017-08-01

Free flap reconstruction of the head and neck is routinely performed with success rates around 94% to 99% at most institutions. Despite experience and meticulous technique, there is a small but recognized risk of partial or total flap loss in the postoperative setting. Historically, most microvascular surgeons involve resident house staff in flap monitoring protocols, and programs relied heavily on in-house resident physicians to assure timely intervention for compromised flaps. In 2003, the Accreditation Council for Graduate Medical Education mandated the reduction in the hours a resident could work within a given week. At many institutions this new era of restricted resident duty hours reshaped the protocols used for flap monitoring to adapt to a system with reduced resident labor. To characterize various techniques and frequencies of free flap monitoring by nurses and resident physicians; and to determine if adapted resident monitoring frequency is associated with flap compromise and outcome. This multi-institutional retrospective review included patients undergoing free flap reconstruction to the head and/or neck between January 2005 and January 2015. Consecutive patients were included from different academic institutions or tertiary referral centers to reflect evolving practices. Technique, frequency, and personnel for flap monitoring; flap complications; and flap success. Overall, 1085 patients (343 women [32%] and 742 men [78%]) from 9 institutions were included. Most patients were placed in the intensive care unit postoperatively (n = 790 [73%]), while the remaining were placed in intermediate care (n = 201 [19%]) or in the surgical ward (n = 94 [7%]). Nurses monitored flaps every hour (q1h) for all patients. Frequency of resident monitoring varied, with 635 patients monitored every 4 hours (q4h), 146 monitored every 8 hours (q8h), and 304 monitored every 12 hours (q12h). Monitoring techniques included physical examination (n = 949 [87%]), handheld external Doppler sonography (n = 739 [68%]), implanted Doppler sonography (n = 333 [31%]), and needle stick (n = 349 [32%]); 105 patients (10%) demonstrated flap compromise, prompting return to the operating room in 96 patients. Of these 96 patients, 46 had complete flap salvage, 22 had partial loss, and 37 had complete loss. The frequency of resident flap checks did not affect the total flap loss rate (q4h, 25 patients [4%]; q8h, 8 patients [6%]; and q12h, 8 patients [3%]). Flap salvage rates for compromised flaps were not statistically different. Academic centers rely primarily on q1h flap checks by intensive care unit nurses using physical examination and Doppler sonography. Reduced resident monitoring frequency did not alter flap salvage nor flap outcome. These findings suggest that institutions may successfully monitor free flaps with decreased resident burden.

Influence of two different flap designs on the sequelae of mandibular third molar surgery.

PubMed

Erdogan, Ozgür; Tatlı, Ufuk; Ustün, Yakup; Damlar, Ibrahim

2011-09-01

The aim of this study was to compare the influence of triangular and envelope flaps on trismus, pain, and facial swelling after mandibular third molar surgery. Twenty healthy patients with bilateral, symmetrically impacted mandibular third molars were included in this double-blinded, prospective, cross-over, randomized study. The patients were operated with envelope flap on one side and triangular flap on the other side. Trismus was determined by measuring maximum interincisal opening, and facial swelling was evaluated using a tape measuring method. Pain was determined using visual analog scale (VAS) and recording the number of pain pills taken. The facial swelling measurements and VAS scores were lower in the envelope flap group compared to the triangular flap group. There was no significant difference between the two flap designs in operation time, maximum interincisal opening, and the number of analgesics taken. Envelope flap yields to less facial swelling and reduced VAS scores in comparison to triangular flap. There is no clinical difference in trismus between the two flap designs. Despite the higher VAS scores with triangular flap, no additional doses of analgesics were required in triangular flap.

Classification and Microvascular Flap Selection for Anterior Cranial Fossa Reconstruction.

PubMed

Vargo, James D; Przylecki, Wojciech; Camarata, Paul J; Andrews, Brian T

2018-05-18

 Microvascular reconstruction of the anterior cranial fossa (ACF) creates difficult challenges. Reconstructive goals and flap selection vary based on the defect location within the ACF. This study evaluates the feasibility and reliability of free tissue transfer for salvage reconstruction of low, middle, and high ACF defects.  A retrospective review was performed. Reconstructions were anatomically classified as low (anterior skull base), middle (frontal bar/sinus), and high (frontal bone/soft tissue). Subjects were evaluated based on pathologic indication and goal, type of flap used, and complications observed.  Eleven flaps in 10 subjects were identified and anatomic sites included: low ( n  = 5), middle ( n  = 3), and high ( n  = 3). Eight of 11 reconstructions utilized osteocutaneous flaps including the osteocutaneous radial forearm free flap (OCRFFF) ( n  = 7) and fibula ( n  = 1). Other reconstructions included a split calvarial graft wrapped within a temporoparietal fascia free flap ( n  = 1), latissimus myocutaneous flap ( n  = 1), and rectus abdominis myofascial flap ( n  = 1). All 11 flaps were successful without microvascular compromise. No complications were observed in the high and middle ACF defect groups. Two of five flaps in the low defect group using OCRFFF flaps failed to achieve surgical goals despite demonstrating healthy flaps upon re-exploration. Complications included persistent cerebrospinal fluid leak ( n  = 1) and pneumocephalus ( n  = 1), requiring flap repositioning in one subject and a second microvascular flap in the second subject to achieve surgical goals.  In our experience, osteocutaneous flaps (especially the OCRFFF) are preferred for complete autologous reconstruction of high and middle ACF defects. Low skull base defects are more difficult to reconstruct, and consideration of free muscle flaps (no bone) should be weighed as an option in this anatomic area. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Results of design studies and wind tunnel tests of high-aspect-ratio supercritical wings for an energy efficient transport

NASA Technical Reports Server (NTRS)

Steckel, D. K.; Dahlin, J. A.; Henne, P. A.

1980-01-01

These basic characteristics of critical wings included wing area, aspect ratio, average thickness, and sweep as well as practical constraints on the planform and thickness near the wing root to allow for the landing gear. Within these constraints, a large matrix of wing designs was studied with spanwise variations in the types of airfoils and distribution of lift as well as some small planform changes. The criteria by which the five candidate wings were chosen for testing were the cruise and buffet characteristics in the transonic regime and the compatibility of the design with low speed (high-lift) requirements. Five wing-wide-body configurations were tested in the NASA Ames 11-foot transonic wind tunnel. Nacelles and pylons, flap support fairings, tail surfaces, and an outboard aileron were also tested on selected configurations.

The combined use of corticotomy and clear aligners: A case report.

PubMed

Cassetta, Michele; Altieri, Federica; Barbato, Ersilia

2016-09-01

To describe an orthodontic treatment that combines an esthetic approach (clear aligners) with surgery (alveolar corticotomy). A patient with moderate dental crowding and Class I skeletal and molar relationships was selected. Orthodontic records of the patient were taken. Periodontal indexes, oral health-related quality of life (OHRQoL), and treatment time were evaluated. After we reflected a full-thickness flap beyond the teeth apices, the cortical bone was exposed on the buccal aspect and a modified corticotomy procedure was performed. Interproximal corticotomy cuts were extended through the entire thickness of the cortical layer, just barely penetrating into medullary bone. Orthodontic force was applied on the teeth immediately after surgery. Total treatment time was 2 months. Periodontal indexes were improved after correction of crowding. A deterioration of OHRQoL was limited to 3 days following surgery. This case report may encourage the use, limited to selected cases, of corticotomy associated with clear aligners to treat moderate crowding.

Risk factors for pedicled flap necrosis in hand soft tissue reconstruction: a multivariate logistic regression analysis.

PubMed

Gong, Xu; Cui, Jianli; Jiang, Ziping; Lu, Laijin; Li, Xiucun

2018-03-01

Few clinical retrospective studies have reported the risk factors of pedicled flap necrosis in hand soft tissue reconstruction. The aim of this study was to identify non-technical risk factors associated with pedicled flap perioperative necrosis in hand soft tissue reconstruction via a multivariate logistic regression analysis. For patients with hand soft tissue reconstruction, we carefully reviewed hospital records and identified 163 patients who met the inclusion criteria. The characteristics of these patients, flap transfer procedures and postoperative complications were recorded. Eleven predictors were identified. The correlations between pedicled flap necrosis and risk factors were analysed using a logistic regression model. Of 163 skin flaps, 125 flaps survived completely without any complications. The pedicled flap necrosis rate in hands was 11.04%, which included partial flap necrosis (7.36%) and total flap necrosis (3.68%). Soft tissue defects in fingers were noted in 68.10% of all cases. The logistic regression analysis indicated that the soft tissue defect site (P = 0.046, odds ratio (OR) = 0.079, confidence interval (CI) (0.006, 0.959)), flap size (P = 0.020, OR = 1.024, CI (1.004, 1.045)) and postoperative wound infection (P < 0.001, OR = 17.407, CI (3.821, 79.303)) were statistically significant risk factors for pedicled flap necrosis of the hand. Soft tissue defect site, flap size and postoperative wound infection were risk factors associated with pedicled flap necrosis in hand soft tissue defect reconstruction. © 2017 Royal Australasian College of Surgeons.

Efficacy of periodontal plastic surgery procedures in the treatment of localized facial gingival recessions. A systematic review.

PubMed

Cairo, Francesco; Nieri, Michele; Pagliaro, Umberto

2014-04-01

The aim of this Systematic Review (SR) was to assess the clinical efficacy of periodontal plastic surgery procedures in the treatment of localized gingival recessions (Rec) with or without inter-dental clinical attachment loss (iCAL). Electronic and hand searches were performed to identify randomized clinical trials (RCTs) on treatment of single gingival recessions with at least 6 months of follow-up. Primary outcome variable was complete root coverage (CRC). Secondary outcome variables were recession reduction (RecRed) and keratinized tissue (KT) gain. To evaluate treatment effect, Odds Ratios were combined for dichotomous data and mean differences in continuous data using a random-effect model. Fifty-one RCTs (53 articles) with a total of 1574 treated patients (1744 recessions) were included in this SR. Finally, 30 groups of comparisons were identified and a total of 80 meta-analyses were performed. Coronally Advanced Flap (CAF) was associated with higher probability of CRC and higher amount of RecRed than Semilunar Coronal Positioned Flap (SCPF). The combination CAF plus Connective Tissue Graft (CAF+CTG) or CAF plus Enamel Matrix Derivative (CAF+EMD) was more effective than CAF alone in terms of CRC and RecRed. The combination CAF plus Collagen Matrix (CAF+CM) achieved higher RecRed than CAF alone. In addition, CAF+CTG achieved CRC more frequently than CAF+EMD, SCPF, Free Gingival Graft (FGG) and Laterally Positioned Flap (LPS). CAF+CTG was also associated with higher RecRed than Barrier Membranes (CAF+GTR), CAF+EMD and CAF+CM. GTR was not able to improve the clinical efficacy of CAF. Studies adding Acellular Dermal Matrix (ADM) under CAF showed a large heterogeneity and not significant benefits compared with CAF alone. Multiple combinations, using more than a single graft/biomaterial under the flap, usually provide similar or less benefits than simpler, control procedures in term of root coverage outcomes. CAF procedures alone or with CTG, EMD are supported by large evidence in modern periodontal plastic surgery. CAF+CTG achieved the best clinical outcomes in single gingival recessions with or without iCAL. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Aerodynamics of Low Reynolds Number Rigid Flapping Wing Under Hover and Freestream Conditions

NASA Astrophysics Data System (ADS)

Trizila, Patrick Clark

Micro air vehicles (MAVs) are defined by all spatial dimensions being less than 15 cm. Equipped with a video camera or a sensor, these vehicles could perform surveillance and reconnaissance with low rates of detection, or environmental and bio-chemical sensing at remote or otherwise hazardous locations. Its size makes the MAV easily transported and deployed as well as inexpensive and more expendable than alternatives, e.g. an airplane, a satellite, or a human. The ability to hover for an MAV is highly desirable in these contexts. The approach taken in the current studies is to numerically simulate the aerodynamics about flapping wings while controlling the kinematic motions and environmental conditions. Two complementary sets of tools were used in the investigations. Navier-Stokes solvers were used to obtain detailed fluid physics information, instantaneous force data, and to train the surrogate models. The surrogate models were used to estimate the average lift and power required over a flapping cycle while also providing information on the sensitivity of the kinematic variables, to identify trends in lift and power required as a function of the kinematic variables, and to construct a Pareto front showing the trade-offs between the competing objectives. Findings include i) an examination of the competing influences introduced by tip vortices, and it was seen that they could increase lift compared to their analogous 2D cases, counter to classical steady state theory. ii) The highest time averaged lift values were found during kinematics with high angles of attack during advanced rotation as they promoted LEV generation and subsequently took advantage of them during wake capture. iii) Kinematics with synchronized rotation and low angles of attack had surprisingly similar 2D and low-aspect-ratio force histories. iv) Modest environmental perturbations, those a fraction of the translational wing velocity, can have a profound impact on the resulting forces. Closely related open questions regard how the Reynolds number, planform shape, and the flapping about a point, with the resulting centripetal accelerations, affect the LEV and tip vortex development. Particularly what guiding principles should be kept in mind when exploring these degrees of freedom in the context of MAV design?

Measurements of donor endothelial keratoplasty lenticules prepared from fresh donated whole eyes by using ultrasound and optical coherence tomography.

PubMed

Kanavi, Mozhgan Rezaei; Nemati, Farzan; Chamani, Tahereh; Kheiri, Bahar; Javadi, Mohammad Ali

2017-03-01

This study was conducted to analyze the profile and thickness of endothelial keratoplasty lenticules prepared from fresh donated whole eyes with Visante optical coherence tomography (V-OCT) compared to measurements obtained from ultrasound pachymetry (USP) at the Central Eye Bank of Iran. Microkeratome-assisted precut corneas were prepared for Descemet stripping automated endothelial keratoplasty by using standard eye bank protocol. Central posterior lenticule thickness (CPLT) on fresh whole eye, before excising corneoscleral disc and transferring to Optisol-GS, was measured by USP. V-OCT was used to measure central, paracentral, and midperipheral thicknesses of lenticules after transferring the tissue to Optisol-GS. Chi Square and Bonferroni tests were respectively used to uncover the differences between the USP and V-OCT measurements and also the thickness profile of lenticules. Postoperative reports for the entire transplanted lenticules were recorded. Accordingly, on evaluation of 312 enrolled precut corneas, CPLT measurements by V-OCT versus USP were statistically different (mean: 136 µm vs 165 µm, respectively; P = 0.008). Thickness profile of the posterior lenticules revealed increased thickness from the central to the peripheral parts of the cornea (mean increase of 16 µm at the pericentral and 64.2 µm at the peripheral locations, respectively); however, the increase in the thickness was relatively symmetrical. Postoperative reports of transplanted lenticules were unremarkable, since there were no posterior flap detachments. In essence, V-OCT measurements of microkeratome-assisted precut lenticules prepared from fresh donated whole eyes averaged 29 μm thinner than USP measurements and revealed a significant but symmetric increase of thickness towards the peripheral parts of the corneas. However, the variation in the thickness profile did not affect the attachment or the clarity of transplanted precut lenticlues.

A Nationwide Analysis of Cost Variation for Autologous Free Flap Breast Reconstruction.

PubMed

Billig, Jessica I; Lu, Yiwen; Momoh, Adeyiza O; Chung, Kevin C

2017-11-01

Cost variation among hospitals has been demonstrated for surgical procedures. Uncovering these differences has helped guide measures taken to reduce health care spending. To date, the fiscal consequence of hospital variation for autologous free flap breast reconstruction is unknown. To investigate factors that influence cost variation for autologous free flap breast reconstruction. A secondary cross-sectional analysis was performed using the Healthcare Cost and Utilization Project National Inpatient Sample database from 2008 to 2010. The dates of analysis were September 2016 to February 2017. The setting was a stratified sample of all US community hospitals. Participants were female patients who were diagnosed as having breast cancer or were at high risk for breast cancer and underwent autologous free flap breast reconstruction. Variables of interest included demographic data, hospital characteristics, length of stay, complications (surgical and systemic), and inpatient cost. The study used univariate and generalized linear mixed models to examine associations between patient and hospital characteristics and cost. A total of 3302 patients were included in the study, with a median age of 50 years (interquartile range, 44-57 years). The mean cost for autologous free flap breast reconstruction was $22 677 (interquartile range, $14 907-$33 391). Flap reconstructions performed at high-volume hospitals were significantly more costly than those performed at low-volume hospitals ($24 360 vs $18 918, P < .001). Logistic regression demonstrated that hospital volume correlated with increased cost (Exp[β], 1.06; 95% CI, 1.02-1.11; P = .003). Fewer surgical complications (16.4% [169 of 1029] vs 23.7% [278 of 1174], P < .001) and systemic complications (24.2% [249 of 1029] vs 31.2% [366 of 1174], P < .001) were experienced in high-volume hospitals compared with low-volume hospitals. Flap procedures performed in the West were the most expensive ($28 289), with a greater odds of increased expenditure (Exp[β], 1.53; 95% CI, 1.46-1.61; P < .001) compared with the Northeast. A significant difference in length of stay was found between the West and Northeast (odds ratio, 1.25; 95% CI, 1.17-1.33). There is significant cost variation among patients undergoing autologous free flap breast reconstruction. Experience, as measured by a hospital's volume, provides quality health care with fewer complications but is more costly. Longer length of stay contributed to regional cost variation and may be a target for decreasing expenditure, without compromising care. In the era of bundled health care payment, strategies should be implemented to eliminate cost variation to condense spending while still providing quality care.

XC-142 Tilt Wing; 0.6 Scale Model in the 40x80 Foot Wind Tunnel at NASA Ames Research Center.

NASA Image and Video Library

1964-01-22

3/4 front right side only with Tim Wills on right and Charles Greco, mechanic. Large flaps on Variable height struts. XC-142 was a tri-service tiltwing experimental aircraft designed to investigate the operational suitability of vertical/short takeoff and landing (V/STOL) transports.

Navier-Stokes Computations of a Wing-Flap Model With Blowing Normal to the Flap Surface

NASA Technical Reports Server (NTRS)

Boyd, D. Douglas, Jr.

2005-01-01

A computational study of a generic wing with a half span flap shows the mean flow effects of several blown flap configurations. The effort compares and contrasts the thin-layer, Reynolds averaged, Navier-Stokes solutions of a baseline wing-flap configuration with configurations that have blowing normal to the flap surface through small slits near the flap side edge. Vorticity contours reveal a dual vortex structure at the flap side edge for all cases. The dual vortex merges into a single vortex at approximately the mid-flap chord location. Upper surface blowing reduces the strength of the merged vortex and moves the vortex away from the upper edge. Lower surface blowing thickens the lower shear layer and weakens the merged vortex, but not as much as upper surface blowing. Side surface blowing forces the lower surface vortex farther outboard of the flap edge by effectively increasing the aerodynamic span of the flap. It is seen that there is no global aerodynamic penalty or benefit from the particular blowing configurations examined.

Reconstruction of lower face defect or deformity with submental artery perforator flaps.

PubMed

Shi, Cheng-li; Wang, Xian-cheng

2012-07-01

Reconstruction of lower face defects or deformity often presents as a challenge for plastic surgeons. Many methods, including skin graft, tissue expander, or free flap are introduced. Submental artery perforator flaps have been used in the reconstruction of defects or deformities of the lower face. Between August 2006 and December 2008, 22 patients with lower face defects or deformity underwent reconstruction with pedicled submental artery perforator flaps. Their age ranged between 14 and 36 years. The perforator arteries were detected and labeled with a hand-held Doppler flowmeter. The size of flaps ranged from 4 × 6 to 6 × 7 cm, and the designed flaps included the perforator artery. All the flaps survived well, except 1 flap which resulted in partial necrosis in distal region and healed after conservative therapy. No other complication occurred with satisfactory aesthetic appearance of the donor site. The submental artery perforator flap is a thin and reliable flap with robust blood supply. This flap can reduce donor-site morbidity significantly and is a good choice for reconstructive surgery of lower face.

Aerodynamic characteristics of a wing with Fowler flaps including flap loads, downwash, and calculated effect on take-off

NASA Technical Reports Server (NTRS)

Platt, Robert C

1936-01-01

This report presents the results of wind tunnel tests of a wing in combination with each of three sizes of Fowler flap. The purpose of the investigation was to determine the aerodynamic characteristics as affected by flap chord and position, the air loads on the flaps, and the effect of flaps on the downwash.

Application of multidetector-row computed tomography in propeller flap planning.

PubMed

Ono, Shimpei; Chung, Kevin C; Hayashi, Hiromitsu; Ogawa, Rei; Takami, Yoshihiro; Hyakusoku, Hiko

2011-02-01

The propeller flap is defined as (1) being island-shaped, (2) having an axis that includes the perforators, and (3) having the ability to be rotated around an axis. The advantage of the propeller flap is that it is a pedicle flap that can be applied to cover defects located at the distal ends of the extremities. The specific aims of the authors' study were (1) to evaluate the usefulness of multidetector-row computed tomography in the planning of propeller flaps and (2) to present a clinical case series of propeller flap reconstructions that were planned preoperatively using multidetector-row computed tomography. The authors retrospectively analyzed all cases between April of 2007 and April of 2010 at Nippon Medical School Hospital in Tokyo, where multidetector-row computed tomography was used preoperatively to plan surgical reconstructions using propeller flaps. Thirteen patients underwent 16 flaps using the propeller flap technique. The perforators were identified accurately by multidetector-row computed tomography preoperatively in all cases. This is the first report describing the application of multidetector-row computed tomography in the planning of propeller flaps. Multidetector-row computed tomography is superior to other imaging methods because it demonstrates more precisely the perforator's position and subcutaneous course using high-resolution three-dimensional images. By using multidetector-row computed tomography to preoperatively identify a flap's perforators, the surgeon can better plan the flap design to efficiently conduct the flap surgery.

Comparison of fasciocutaneous V-Y and rotational flaps for defect coverage of sacral pressure sores: a critical single-centre appraisal.

PubMed

Djedovic, Gabriel; Metzler, Julia; Morandi, Evi M; Wachter, Tanja; Kühn, Shafreena; Pierer, Gerhard; Rieger, Ulrich M

2017-12-01

Pressure sore rates remain high in both nursing homes as well as in hospitals. Numerous surgical options are available for defect coverage in the sacral region. However, objective data is scarce as to whether a specific flap design is superior to another. Here, we aim to compare two fasciocutaneous flap designs for sacral defect coverage: the gluteal rotation flap and the gluteal V-Y flap. All primary sacral pressure sores of grades III-IV that were being covered with gluteal fasciocutaneous rotational or V-Y flaps between January 2008 and December 2014 at our institution were analysed. A total of 41 patients received a total of 52 flaps. Of these, 18 patients received 20 gluteal rotational flaps, and 23 patients received 32 V-Y flaps. Both groups were comparable with regards to demographics, comorbidities and complications. Significantly more V-Y flaps were needed to cover smaller defects. Mean length of hospital stay was significantly prolonged when surgical revision had to be carried out. Both flap designs have proven safe and reliable for defect coverage after sacral pressure sores. Gluteal rotational flaps appear to be more useful for larger defects. Both flap designs facilitate their reuse in case of pressure sore recurrence. Complication rates appear to be comparable in both designs and to the current literature. © 2017 Medicalhelplines.com Inc and John Wiley & Sons Ltd.

Glove box shield

DOEpatents

Brackenbush, L.W.; Hoenes, G.R.

A shield for a glove box housing radioactive material is comprised of spaced apart clamping members which maintain three overlapping flaps in place therebetween. There is a central flap and two side flaps, the side flaps overlapping at the interior edges thereof and the central flap extending past the intersection of the side flaps in order to insure that the shield is always closed when the user wthdraws his hand from the glove box. Lead loaded neoprene rubber is the preferred material for the three flaps, the extent of lead loading depending upon the radiation levels within the glove box.

Aeroelastic Analysis of a Flexible Wing Wind Tunnel Model with Variable Camber Continuous Trailing Edge Flap Design

NASA Technical Reports Server (NTRS)

Nguyen, Nhan; Ting, Eric; Lebofsky, Sonia

2015-01-01

This paper presents data analysis of a flexible wing wind tunnel model with a variable camber continuous trailing edge flap (VCCTEF) design for drag minimization tested at the University of Washington Aeronautical Laboratory (UWAL). The wind tunnel test was designed to explore the relative merit of the VCCTEF concept for improved cruise efficiency through the use of low-cost aeroelastic model test techniques. The flexible wing model is a 10%-scale model of a typical transport wing and is constructed of woven fabric composites and foam core. The wing structural stiffness in bending is tailored to be half of the stiffness of a Boeing 757-era transport wing while the torsional stiffness is about the same. This stiffness reduction results in a wing tip deflection of about 10% of the wing semi-span. The VCCTEF is a multi-segment flap design having three chordwise camber segments and five spanwise flap sections for a total of 15 individual flap elements. The three chordwise camber segments can be positioned appropriately to create a desired trailing edge camber. Elastomeric material is used to cover the gaps in between the spanwise flap sections, thereby creating a continuous trailing edge. Wind tunnel data analysis conducted previously shows that the VCCTEF can achieve a drag reduction of up to 6.31% and an improvement in the lift-to-drag ratio (L=D) of up to 4.85%. A method for estimating the bending and torsional stiffnesses of the flexible wingUWAL wind tunnel model from static load test data is presented. The resulting estimation indicates that the stiffness of the flexible wing is significantly stiffer in torsion than in bending by as much as 9 to 1. The lift prediction for the flexible wing is computed by a coupled aerodynamic-structural model. The coupled model is developed by coupling a conceptual aerodynamic tool Vorlax with a finite-element model of the flexible wing via an automated geometry deformation tool. Based on the comparison of the lift curve slope, the lift prediction for the rigid wing is in good agreement with the estimated lift coefficients derived from the wind tunnel test data. Due to the movement of the VCCTEF during the wind tunnel test, uncertainty in the lift prediction due to the indicated variations of the VCCTEF deflection is studied. The results show a significant spread in the lift prediction which contradicts the consistency in the aerodynamic measurements, thus suggesting that the indicated variations as measured by the VICON system may not be reliable. The lift prediction of the flexible wing agrees very well with the measured lift curve for the baseline configuration. The computed bending deflection and wash-out twist of the flexible wing also match reasonably well with the aeroelastic deflection measurements. The results demonstrate the validity of the aerodynamic-structural tool for use to analyze aerodynamic performance of flexible wings.

[Management of vascular crisis of free flaps after reconstruction of head and neck defects caused by tumor resection].

PubMed

Ni, Song; Zhu, Yiming; Li, Dezhi; Liu, Jie; An, Changming; Zhang, Bin; Liu, Shaoyan

2015-11-01

To discuss the management of vascular crisis of free flaps after reconstruction of head and neck defects caused by tumor resection. A total of 259 cases of free flap reconstruction performed in the Cancer Hospital of Chinese Academy of Medical Sciences from 2010 to 2013 were retrospectively analyzed, including 89 cases of anterolateral thigh flaps, 48 cases of radial forearm flaps, 46 free fibula flaps, 5 cases of inferior epigastric artery perforator flaps, 5 cases of free latissimus dorsi flaps, one case of lateral arm flap, and one case of medial femoral flap. The surveillance frequency of free flaps was q1h on post-operative day (POD) 1, q2h on POD 2 and 3, and q4h after POD 3. Vascular crises were reviewed for analysis. The incidence rate of vascular crisis was 8.1% (21/259), with 15 males and 6 females. The average age was 54.8 years old (17-68), and the average time of vascular crisis was 100.8 h post-operation (3-432). There were 7 cases of free jejunum flaps and 14 dermal free flaps. Seven of these 21 cases with vascular crisis were rescued by surgery. The success rate of salvage surgery within 72 hours from the primary operation was 54.5% (6/11), significantly higher than that of salvage surgery performed later than 72 hours from primary operation (10.0%, 1/10, P=0.043). There were 14 cases of flap necrosis, two of which died of local infection. Early detection of vascular crisis can effectively improve the success rate of salvage, so as to avoid the serious consequences caused by free flap necrosis.

Indocyanine Green Fluorescence for Free-Flap Perfusion Imaging Revisited: Advanced Decision Making by Virtual Perfusion Reality in Visionsense Fusion Imaging Angiography.

PubMed

Bigdeli, Amir Khosrow; Gazyakan, Emre; Schmidt, Volker Juergen; Hernekamp, Frederick Jochen; Harhaus, Leila; Henzler, Thomas; Kremer, Thomas; Kneser, Ulrich; Hirche, Christoph

2016-06-01

Near-infrared indocyanine green video angiography (ICG-NIR-VA) has been introduced for free-flap surgery and may provide intraoperative flap designing as well as postoperative monitoring. Nevertheless, the technique has not been established in clinical routine because of controversy over benefits. Improved technical features of the novel Visionsense ICG-NIR-VA surgery system are promising to revisit the field of application. It features a unique real-time fusion image of simultaneous NIR and white light visualization, with highlighted perfusion, including a color-coded perfusion flow scale for optimized anatomical understanding. In a feasibility study, the Visionsense ICG-NIR-VA system was applied during 10 free-flap surgeries in 8 patients at our center. Indications included anterior lateral thigh (ALT) flap (n = 4), latissimus dorsi muscle flap (n = 1), tensor fascia latae flap (n = 1), and two bilateral deep inferior epigastric artery perforator flaps (n = 4). The system was used intraoperatively and postoperatively to investigate its impact on surgical decision making and to observe perfusion patterns correlated to clinical monitoring. Visionsense ICG-NIR-VA aided assessing free-flap design and perfusion patterns in all cases and correlated with clinical observations. Additional interventions were performed in 2 cases (22%). One venous anastomosis was revised, and 1 flap was redesigned. Indicated by ICG-NIR-VA, 1 ALT flap developed partial flap necrosis (11%). The Visionsense ICG-NIR-VA system allowed a virtual view of flap perfusion anatomy by fusion imaging in real-time. The system improved decision making for flap design and surgical decisions. Clinical and ICG-NIR-VA parameters correlated. Its future implementation may aid in improving outcomes for free-flap surgery, but additional experience is needed to define its final role. © The Author(s) 2015.

Reconstruction Using Locoregional Flaps for Large Skull Base Defects.

PubMed

Hatano, Takaharu; Motomura, Hisashi; Ayabe, Shinobu

2015-06-01

We present a modified locoregional flap for the reconstruction of large anterior skull base defects that should be reconstructed with a free flap according to Yano's algorithm. No classification of skull base defects had been proposed for a long time. Yano et al suggested a new classification in 2012. The lb defect of Yano's classification extends horizontally from the cribriform plate to the orbital roof. According to Yano's algorithm for subsequent skull base reconstructive procedures, a lb defect should be reconstructed with a free flap such as an anterolateral thigh free flap or rectus abdominis myocutaneous free flap. However, our modified locoregional flap has also enabled reconstruction of lb defects. In this case series, we used a locoregional flap for lb defects. No major postoperative complications occurred. We present our modified locoregional flap that enables reconstruction of lb defects.

Development of Bird-like Micro Aerial Vehicle with Flapping and Feathering Wing Motions

NASA Astrophysics Data System (ADS)

Maglasang, Jonathan; Goto, Norihiro; Isogai, Koji

To investigate the feasibility of a highly efficient flapping system capable of avian maneuvers, such as rapid takeoff, hover and gliding, a full scale bird-like (ornithopter) flapping-wing micro aerial vehicle (MAV) shaped and patterned after a typical pigeon (Columba livia) has been designed and constructed. Both numerical and experimental methods have been used in the development of this vehicle. This flapping-wing micro aerial vehicle utilizes both the flapping and feathering motions of an avian wing by employing a novel flapping-feathering mechanism, which has been synthesized and constructed so as to best describe the properly coordinated flapping and feathering wing motions at phase angle difference of 90° in a horizontal steady level flight condition. This design allows high flapping and feathering amplitudes and is configurable for asymmetric wing motions which are desirable in high-speed flapping flight and maneuvering. The preliminary results indicate its viability as a practical and an efficient flapping-wing micro aerial vehicle.

Reconstructive Trends in Post-Ablation Patients with Esophagus and Hypopharynx Defect

PubMed Central

Choi, Jong Hwan; Sim, Seung Hyun

2015-01-01

The main challenge in pharyngoesophageal reconstruction is the restoration of swallow and speech functions. The aim of this paper is to review the reconstructive options and associated complications for patients with head and neck cancer. A literature review was performed for pharynoesophagus reconstruction after ablative surgery of head and neck cancer for studies published between January 1980 to July 2015 and listed in the PubMed database. Search queries were made using a combination of 'esophagus' and 'free flap', 'microsurgical', or 'free tissue transfer'. The search query resulted in 123 studies, of which 33 studies were full text publications that met inclusion criteria. Further review into the reference of these 33 studies resulted in 15 additional studies to be included. The pharyngoesophagus reconstruction should be individualized for each patient and clinical context. Fasciocutaneous free flap and pedicled flap are effective for partial phayngoesophageal defect. Fasciocutaneous free flap and jejunal free flap are effective for circumferential defect. Pedicled flaps remain a safe option in the context of high surgical risk patients, presence of fistula. Among free flaps, anterolateral thigh free flap and jejunal free flap were associated with superior outcomes, when compared with radial forearm free flap. Speech function is reported to be better for the fasciocutaneous free flap than for the jejunal free flap. PMID:28913234

Proximally pedicled medial plantar flap based on superficial venous system alone for venous drainage.

PubMed

Wright, Thomas C; Mossaad, Bassem M; Chummun, Shaheel; Khan, Umraz; Chapman, Thomas W L

2013-07-01

The proximally pedicled medial plantar flap is well described for coverage of wounds around the ankle and heel. This flap is usually based on the deep venae comitantes for venous drainage, with the superficial veins divided during dissection. Usually any disruption of the deep venous system of the flap would result in abandoning this choice of flap. Venous congestion is a recognised complication of medial plantar flaps. The patient described in this case report had a medial ankle defect with exposed bone, for which a proximally pedicled medial plantar flap was used. As we raised the flap, both venae comitantes of the medial planter artery were found to be disrupted. The flap was raised based on the superficial veins draining into the great saphenous, as the only system for venous drainage, with no evidence of venous congestion. The flap was successfully transposed into the defect and healed with no complications. The proximally pedicled medial plantar flap can safely rely on the superficial venous system alone for drainage. In addition, preserving the superficial veins minimise the risk of venous congestion in this flap. We recommend preservation of superficial venous system when possible. Copyright © 2013 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

Reconstruction of cubital fossa skin necrosis with radial collateral artery perforator-based propeller flap (RCAP).

PubMed

Chaput, B; Gandolfi, S; Ho Quoc, C; Chavoin, J-P; Garrido, I; Grolleau, J-L

2014-02-01

In recent years, perforator flaps have become an indispensable tool for the reconstruction process. Most recently, "propeller" perforator flaps allow each perforator vessels to become a flap donor site. Once the perforator of interest is identified by acoustic Doppler, the cutaneous or fascio-cutaneous island is designed and then customized according to the principle of "perforasome". So, the flap can be rotated such a propeller, up to 180°. Ideally the donor site is self-closing, otherwise it can be grafted at the same time. Through a skin necrosis secondary to a contrast medium extravasation of the cubital fossa in a 47-year-old man, we describe the use of propeller perforator flap based on a perforator of the radial collateral artery (RCAP). The perforator was identified preoperatively by acoustic Doppler then the flap was adapted bespoke to cover the loss of substance. Ultimately, the result was very satisfying. Well experienced for lower-extremity reconstruction, perforator-based propeller flap are still few reported for upper limb. It is likely that in the future, propeller flap supersede in many indication not only free flaps and locoregional flaps but also, leaving no room for uncertainties of the vascular network, the classic random flaps. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

[Surgical issues and outcomes in ischial pressure sores treatment].

PubMed

Voulliaume, D; Grecea, M; Viard, R; Brun, A; Comparin, J-P; Foyatier, J-L

2011-12-01

Ischiatic pressure sores are frequent in spinal cord injury patients, associated with bad prognosis and high recurrence rate. Many surgical techniques were described, including surgical debridement followed by pedicled flap coverage. We aim to propose a practical decision tree for primary or secondary ischial pressure sore treatment. Our series of 48 operated ischial sores with an average follow up of 4 years (range 2 to 8years) is analyzed and compared to previously published reports. Surgical techniques are discussed according to their specific indications. The optimal recurrence rate in published reports about pressure sore treatment is 20%; a rate inferior to 19% is found in our series, showing the equal importance of flap selection and postoperative care and education. Depending on each situation, various available flaps are described and compared: gluteus maximus flap, biceps femoris flap, gracilis flap, tensor fascia lata flap, fasciocutaneous thigh flaps, rectus femoris and vastus lateralis flap, rectus abdominis flap. Specific surgical indications for more extensive wounds are studied: resection arthroplasty of the hip, hip disarticulation, fillet flaps from the leg, microsurgery. Based upon our experience, a decision tree summarizes our proposition of flap selection, depending on the wound size and the patient background. Copyright © 2010 Elsevier Masson SAS. All rights reserved.

Altitude Cooling Investigation of the R-2800-21 Engine in the P-47G Airplane. IV - Engine Cooling-Air Pressure Distribution

NASA Technical Reports Server (NTRS)

Kaufman, Samuel J.; Staudt, Robert C.; Valerino, Michael F.

1947-01-01

A study of the data obtained in a flight investigation of an R-2800-21 engine in a P-47G airplane was made to determine the effect of the flight variables on the engine cooling-air pressure distribution. The investigation consisted of level flights at altitudes from 5000 to 35,000 feet for the normal range of engine and airplane operation. The data showed that the average engine front pressures ranged from 0.73 to 0.82 of the impact pressure (velocity head). The average engine rear pressures ranged from 0.50 to 0.55 of the impact pressure for closed cowl flaps and from 0.10 to 0.20 for full-open cowl flaps. In general, the highest front pressures were obtained at the bottom of the engine. The rear pressures for the rear-row cylinders were .lower and the pressure drops correspondingly higher than for the front-row cylinders. The rear-pressure distribution was materially affected by cowl-flap position in that the differences between the rear pressures of the front-row and rear-row cylinders markedly increased as the cowl flaps were opened. For full-open cowl flaps, the pressure drops across the rear-row cylinders were in the order of 0.2 of the impact pressure greater than across the front-row cylinders. Propeller speed and altitude had little effect on the -coolingair pressure distribution, Increase in angle of inclination of the thrust axis decreased the front ?pressures for the cylinders at the top of the engine and increased them for the cylinders at the bottom of the engine. As more auxiliary air was taken from the engine cowling, the front pressures and, to a lesser extent, the rear pressures for the cylinders at the bottom of the engine decreased. No correlation existed between the cooling-air pressure-drop distribution and the cylinder-temperature distribution.

Freestyle multiple propeller flap reconstruction (jigsaw puzzle approach) for complicated back defects.

PubMed

Park, Sung Woo; Oh, Tae Suk; Eom, Jin Sup; Sun, Yoon Chi; Suh, Hyun Suk; Hong, Joon Pio

2015-05-01

The reconstruction of the posterior trunk remains to be a challenge as defects can be extensive, with deep dead space, and fixation devices exposed. Our goal was to achieve a tension-free closure for complex defects on the posterior trunk. From August 2006 to May 2013, 18 cases were reconstructed with multiple flaps combining perforator(s) and local skin flaps. The reconstructions were performed using freestyle approach. Starting with propeller flap(s) in single or multilobed design and sequentially in conjunction with adjacent random pattern flaps such as fitting puzzle. All defects achieved tensionless primary closure. The final appearance resembled a jigsaw puzzle-like appearance. The average size of defect was 139.6 cm(2) (range, 36-345 cm(2)). A total of 26 perforator flaps were used in addition to 19 random pattern flaps for 18 cases. In all cases, a single perforator was used for each propeller flap. The defect and the donor site all achieved tension-free closure. The reconstruction was 100% successful without flap loss. One case of late infection was noted at 12 months after surgery. Using multiple lobe designed propeller flaps in conjunction with random pattern flaps in a freestyle approach, resembling putting a jigsaw puzzle together, we can achieve a tension-free closure by distributing the tension to multiple flaps, supplying sufficient volume to obliterate dead space, and have reliable vascularity as the flaps do not need to be oversized. This can be a viable approach to reconstruct extensive defects on the posterior trunk. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

The transverse musculocutaneous gracilis flap for breast reconstruction: guidelines for flap and patient selection.

PubMed

Schoeller, Thomas; Huemer, Georg M; Wechselberger, Gottfried

2008-07-01

The transverse musculocutaneous gracilis (TMG) flap has received little attention in the literature as a valuable alternative source of donor tissue in the setting of breast reconstruction. The authors give an in-depth review of their experience with breast reconstruction using the TMG flap. A retrospective review of 111 patients treated with a TMG flap for breast reconstruction in an immediate or a delayed setting between August of 2002 and July of 2007 was undertaken. Of these, 26 patients underwent bilateral reconstruction and 68 underwent unilateral reconstruction, and 17 patients underwent reconstruction unilaterally with a double TMG flap. Patient age ranged between 24 and 65 years (mean, 37 years). Twelve patients had to be taken back to the operating room because of flap-related problems and nine patients underwent successful revision microsurgically, resulting in three complete flap losses in a series of 111 patients with 154 transplanted TMG flaps. Partial flap loss was encountered in two patients, whereas fat tissue necrosis was managed conservatively in six patients. Donor-site morbidity was an advantage of this flap, with a concealed scar and minimal contour irregularities of the thigh, even in unilateral harvest. Complications included delayed wound healing (n = 10), hematoma (n = 5), and transient sensory deficit over the posterior thigh (n = 49). The TMG flap is more than an alternative to the deep inferior epigastric perforator (DIEP) flap in microsurgical breast reconstruction in selected patients. In certain indications, such as bilateral reconstructions, it possibly surpasses the DIEP flap because of a better concealed donor scar and easier harvest.

Interventions for replacing missing teeth: management of soft tissues for dental implants.

PubMed

Esposito, Marco; Maghaireh, Hassan; Grusovin, Maria Gabriella; Ziounas, Ioannis; Worthington, Helen V

2012-02-15

Dental implants are usually placed by elevating a soft tissue flap, but in some instances, they can also be placed flapless reducing patient discomfort. Several flap designs and suturing techniques have been proposed. Soft tissues are often manipulated and augmented for aesthetic reasons. It is often recommended that implants are surrounded by a sufficient width of attached/keratinised mucosa to improve their long-term prognosis. To evaluate whether (1a) flapless procedures are beneficial for patients, and (1b) which is the ideal flap design; whether (2a) soft tissue correction/augmentation techniques are beneficial for patients, and (2b) which are the best techniques; whether (3a) techniques to increase the peri-implant keratinised mucosa are beneficial for patients, and (3b) which are the best techniques; and (4) which are the best suturing techniques/materials. The following electronic databases were searched: the Cochrane Oral Health Group Trials Register (to 9 June 2011), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2011, Issue 2), MEDLINE via OVID (1950 to 9 June 2011), EMBASE via OVID (1980 to 9 June 2011). Several dental journals were handsearched. There were no language restrictions. All randomised controlled trials (RCTs) of root-form osseointegrated dental implants, with a follow-up of at least 6 months after function, comparing various techniques to handle soft tissues in relation to dental implants. Outcome measures, according to the different hypotheses, were: prosthetic and implant failures, biological complications, aesthetics evaluated by patients and dentists, postoperative pain, marginal peri-implant bone level changes on periapical radiographs, patient preference, ease of maintenance by patient, soft tissue thickness changes and attached/keratinised mucosa height changes. Screening of eligible studies, assessment of the methodological quality of the trials and data extraction were conducted at least in duplicate and independently by two or more review authors. Trial authors were contacted for missing information. Results were expressed using risk ratios for dichotomous outcomes and mean differences for continuous outcomes with 95% confidence intervals. Seventeen potentially eligible RCTs were identified but only six trials with 138 patients in total could be included. One study was at low risk of bias, two studies were judged to be at unclear risk of bias and three at high risk of bias. Two trials (56 patients) compared flapless placement of dental implants with conventional flap elevation, one trial (10 patients) compared crestal versus vestibular incisions, one trial (20 patients) Erbium:YAG laser versus flap elevation at the second-stage surgery for implant exposure, one split-mouth trial (10 patients) evaluated whether connective tissue graft at implant placement could be effective in augmenting peri-implant tissues, and one trial (40 patients) compared autograft with an animal-derived collagen matrix to increase the height of the keratinised mucosa. On a patient, rather than per implant basis, implants placed with a flapless technique and implant exposures performed with laser induced statistically significantly less postoperative pain than flap elevation. Sites augmented with soft tissues connective grafts showed a better aesthetic and thicker tissues. Both palatal autografts or the use of a porcine-derived collagen matrix are effective in increasing the height of keratinised mucosa at the price of a 0.5 mm recession of peri-implant soft tissues. There were no other statistically significant differences for any of the remaining analyses. There is limited weak evidence suggesting that flapless implant placement is feasible and has been shown to reduce patient postoperative discomfort in adequately selected patients, that augmentation at implant sites with soft tissue grafts is effective in increasing soft tissue thickness improving aesthetics and that one technique to increase the height of keratinised mucosa using autografts or an animal-derived collagen matrix was able to achieve its goal but at the price of a worsened aesthetic outcome (0.5 mm of recession). There is insufficient reliable evidence to provide recommendations on which is the ideal flap design, the best soft tissue augmentation technique, whether techniques to increase the width of keratinised/attached mucosa are beneficial to patients or not, and which are the best incision/suture techniques/materials. Properly designed and conducted RCTs, with at least 6 months of follow-up, are needed to provide reliable answers to these questions.

Closed loop performance of a brushless dc motor powered electromechanical actuator for flight control applications. [computerized simulation for Shuttle Orbiter applications

NASA Technical Reports Server (NTRS)

Demerdash, N. A.; Nehl, T. W.

1980-01-01

A comprehensive digital model for the analysis and possible optimization of the closed loop dynamic (instantaneous) performance of a power conditioner fed, brushless dc motor powered, electromechanical actuator system (EMA) is presented. This model was developed for the simulation of the dynamic performance of an actual prototype EMA built for NASA-JSC as a possible alternative to hydraulic actuators for consideration in Space Shuttle Orbiter applications. Excellent correlation was achieved between numerical model simulation and experimental test results obtained from the actual hardware. These results include: various current and voltage waveforms in the machine-power conditioner (MPC) unit, flap position as well as other control loop variables in response to step commands of change of flap position. These results with consequent conclusions are detailed in the paper.

Calculated Low-Speed Steady and Time-Dependent Aerodynamic Derivatives for Some Airfoils Using a Discrete Vortex Method

NASA Technical Reports Server (NTRS)

Riley, Donald R.

2015-01-01

This paper contains a collection of some results of four individual studies presenting calculated numerical values for airfoil aerodynamic stability derivatives in unseparated inviscid incompressible flow due separately to angle-of-attack, pitch rate, flap deflection, and airfoil camber using a discrete vortex method. Both steady conditions and oscillatory motion were considered. Variables include the number of vortices representing the airfoil, the pitch axis / moment center chordwise location, flap chord to airfoil chord ratio, and circular or parabolic arc camber. Comparisons with some experimental and other theoretical information are included. The calculated aerodynamic numerical results obtained using a limited number of vortices provided in each study compared favorably with thin airfoil theory predictions. Of particular interest are those aerodynamic results calculated herein (such as induced drag) that are not readily available elsewhere.

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing flap controls. 23.697 Section 23.697... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2011 CFR

2011-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flap controls. 23.697 Section 23.697...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2012 CFR

2012-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flap controls. 23.697 Section 23.697...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2014 CFR

2014-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flap controls. 23.697 Section 23.697...

14 CFR 23.697 - Wing flap controls.

Code of Federal Regulations, 2010 CFR

2010-01-01

... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing flap controls. 23.697 Section 23.697...

Vascular Patterns and Perfusion of Mucogingival Tissues and their Relation to Periodontal Flap Design

DTIC Science & Technology

1987-05-01

flaps were mosL vulnerable to necrosis . Sutures placed with minimal tension did not adversely affect blood perfusion of surgically replaced flaps. vi * C...perfusion change with narrow flaps most severely affected. In general, narrow thin flaps were most vulnerable to necrosis . Sutures placed with minimal...Day Narrow Pedicle ............. 75 B. Fluorescein Angiography of Envelope Flap Immediately Post Surgery and Necrosis of Marginal Third of Six

Glove box shield

DOEpatents

Brackenbush, Larry W.; Hoenes, Glenn R.

1981-01-01

According to the present invention, a shield for a glove box housing radioactive material is comprised of spaced apart clamping members which maintain three overlapping flaps in place therebetween. There is a central flap and two side flaps, the side flaps overlapping at the interior edges thereof and the central flap extending past the intersection of the side flaps in order to insure that the shield is always closed when the user withdraws his hand from the glove box. Lead loaded neoprene rubber is the preferred material for the three flaps, the extent of lead loading depending upon the radiation levels within the glove box.

Biomimetic Beetle-Inspired Flapping Air Vehicle Actuated by Ionic Polymer-Metal Composite Actuator.

PubMed

Zhao, Yang; Xu, Di; Sheng, Jiazheng; Meng, Qinglong; Wu, Dezhi; Wang, Lingyun; Xiao, Jingjing; Lv, Wenlong; Chen, Qinnan; Sun, Daoheng

2018-01-01

During the last decades, the ionic polymer-metal composite (IPMC) received much attention because of its potential capabilities, such as large displacement and flexible bending actuation. In this paper, a biomimetic flapping air vehicle was proposed by combining the superiority of ionic polymer metal composite with the bionic beetle flapping principle. The blocking force was compared between casted IPMC and IPMC. The flapping state of the wing was investigated and the maximum displacement and flapping angle were measured. The flapping displacement under different voltage and frequency was tested. The flapping displacement of the wing and the support reaction force were measured under different frequency by experiments. The experimental results indicate that the high voltage and low frequency would get large flapping displacement.

Piloted simulation study of two tilt-wing control concepts

NASA Technical Reports Server (NTRS)

Birckelbaw, Lourdes G.; Corliss, Lloyd D.

1994-01-01

A two-phase piloted simulation study was conducted to investigate alternative wing and flap controls for tilt-wing aircraft. The initial phase of the study compared the flying qualities of both a conventional (programmed) flap and an innovative geared flap. The second phase of the study introduced an alternate method of pilot control for the geared flap and further studied the flying qualities of the programmed flap, and two geared flap configurations. In general, the pilot rating showed little variation between the programmed flap and the geared flap control concepts. Some differences between the two concepts were noticed and are discussed in this paper. The addition of pitch attitude stabilization in the second phase of the study greatly enhanced the aircraft flying qualities. This paper describes the simulated tilt-wing aircraft and the flap control concepts and presents the results of both phases of the simulation study.

The unique and valuable soft tissue free flap in head and neck reconstruction: Lateral arm.

PubMed

Kang, Stephen Y; Eskander, Antoine; Patel, Krupal; Teknos, Theodoros N; Old, Matthew O

2018-07-01

While the lateral arm free flap has been well described, there is a relative paucity in its use compared to other free flaps and regional flaps. The lateral arm free flap is a unique soft tissue free flap that provides several reconstructive advantages in head and neck reconstruction: excellent contour and color match to facial skin, well compartmentalized fat, donor nerves for nerve grafting, and the ability to two-team harvest and close the donor site without a skin graft. A detailed anatomic and harvest technique is described, along with indications and advantages of using lateral free flap for head and neck reconstruction. A scoping literature review was also conducted to tabulate indications, overall success and complications of the flap. The lateral arm flap is a primary option for defects requiring soft tissue reconstruction in the head and neck. Copyright © 2018 Elsevier Ltd. All rights reserved.

Optimization design and dynamic analysis on the drive mechanisms of flapping-wing air vehicles based on flapping trajectories

NASA Astrophysics Data System (ADS)

Xie, Lingwang; Zhang, Xingwei; Luo, Pan; Huang, Panpan

2017-10-01

The optimization designs and dynamic analysis on the driving mechanism of flapping-wing air vehicles on base of flapping trajectory patterns is carried out in this study. Three different driving mechanisms which are spatial double crank-rocker, plane five-bar and gear-double slider, are systematically optimized and analysed by using the Mat lab and Adams software. After a series debugging on the parameter, the comparatively ideal flapping trajectories are obtained by the simulation of Adams. Present results indicate that different drive mechanisms output different flapping trajectories and have their unique characteristic. The spatial double crank-rocker mechanism can only output the arc flapping trajectory and it has the advantages of small volume, high flexibility and efficient space utilization. Both planar five-bar mechanism and gear-double slider mechanism can output the oval, figure of eight and double eight flapping trajectories. Nevertheless, the gear-double slider mechanism has the advantage of convenient parameter setting and better performance in output double eight flapping trajectory. This study can provide theoretical basis and helpful reference for the design of the drive mechanisms of flapping-wing air vehicles with different output flapping trajectories.

Lower Extremity Free Flaps for Breast Reconstruction.

PubMed

Dayan, Joseph H; Allen, Robert J

2017-11-01

Thigh-based flaps are typically a secondary option for breast reconstruction because of concerns regarding limited tissue volume and donor-site morbidity. In recent years, there have been a number of new techniques and insights that have resulted in greater flexibility and improved outcomes. This article reviews lessons learned from a large collective experience using the following 4 flaps: transverse upper gracilis also known as transverse myocutaneous gracilis, diagonal upper gracilis, profunda artery perforator, and lateral thigh perforator flaps. Flap selection considerations include the patient's fat distribution and skin laxity, perforator anatomy, and scar location. Pearls to minimize donor-site morbidity include avoiding major lymphatic collectors in the femoral triangle and along the greater saphenous vein and respecting the limits of flap dimension to reduce wound healing complications and distal ischemia. Limited flap volume may be addressed with stacking another flap from the contralateral thigh or primary fat grafting as opposed to overaggressive flap harvest from a single thigh. A detailed review of the benefits and disadvantages of each flap and strategies to improve results is discussed. With careful planning and selection, thigh-based flaps can provide a reliable option patients desiring autologous breast reconstruction.

A performance application study of a jet-flap helicopter rotor

NASA Technical Reports Server (NTRS)

Sullivan, R. J.; Laforge, S.; Holchin, B. W.

1972-01-01

A performance study was made of the application of a jet-flap to a reaction-drive rotor for a heavy-lift helicopter mission and for a high-speed-helicopter maneuverability (200 knots, 2g) mission. The results of the study are as follows: As a result of the increase in maximum airfoil lift coefficient achieved by the jet-flap, rotor solidity is reduced with the jet-flap to approximately 59% of a nonjet-flap rotor. As a result of the saving in rotor solidity, and hence in rotor weight, the jet-flap configuration had a 21% higher productivity than a nonjet-flap configuration. Of the three propulsion systems studied utilizing a jet-flap (hot cycle, warm cycle, cold cycle) the hot cycle gave the largest increase in productivity. The 200 knot 2g mission is performed best with a warm cycle propulsion system. The jet-flap permits designing for a rotor blade loading coefficient C sub T/sigma = .170 at 2g without encountering blade stall. The jet-flap rotor permits a 200 knot 2g maneuver without suffering the penalty of an unreasonable rotor solidity that would be required by a nonjet-flap rotor.

[A reverse vascular autograft finger island flap. A review of 15 cases and of the literature].

PubMed

Adani, R; Marcuzzi, A; Busa, R; Pancaldi, G; Bathia, A; Caroli, A

1995-01-01

The authors discuss the indications for homodigital island flap with a reverse vascular pedicle. This flap is based on the anastomoses between the radial and ulnar digital arteries. These anastomotic branches lie between the posterior wall of the tendon sheath and the periosteum to form an arch and are named the "digitopalmar arches". The vascularization of the reverse homodigital island flap is derived by using the middle transverse palmar arch. This flap was performed successfully in 14 patients involving 15 fingers to resurface amputation of the distal phalanx. In 6 cases the flap was used as an "artery" flap, and in 9 cases as a "sensitive" homodigital island flap. The pedicle in these cases was neurovascular also containing the digital nerve. The sensitivity of the flap was obtained by neurorraphy between the transposed digital nerve of the flap and the receiving digital nerve of the recipient finger. This technique achieves cover of the tactile pad in one operative stage and provides well vascularized skin allowing early mobilization. Sensation of the flap can be restored rapidly when neurorraphy of the transposed digital nerve is performed.

Reconstruction of pressure sores with perforator-based propeller flaps.

PubMed

Jakubietz, Rafael G; Jakubietz, Danni F; Zahn, Robert; Schmidt, Karsten; Meffert, Rainer H; Jakubietz, Michael G

2011-03-01

Perforator flaps have been successfully used for reconstruction of pressure sores. Although V-Y advancement flaps approximate debrided wound edges, perforator-based propeller flaps allow rotation of healthy tissue into the defect. Perforator-based propeller flaps were planned in 13 patients. Seven pressure sores were over the sacrum, five over the ischial tuberosity, and one on the tip of the scapula. Three patients were paraplegic, six were bedridden, and five were ambulatory. In three patients, no perforators were found. In 10 patients, propeller flaps were transferred. In two patients, total flap necrosis occurred, which was reconstructed with local advancement flaps. In two cases, a wound dehiscence occurred and had to be revised. One hematoma required evacuation. No further complications were noted. No recurrence at the flap site occurred. Local perforator flaps allow closure of pressure sores without harvesting muscle. The propeller version has the added benefit of transferring tissue from a distant site, avoiding reapproximation of original wound edges. Twisting of the pedicle may cause torsion and venous obstruction. This can be avoided by dissecting a pedicle of at least 3 cm. Propeller flaps are a safe option for soft tissue reconstruction of pressure sores. © Thieme Medical Publishers.

Low-Speed Wind-Tunnel Investigation of Blowing Boundary-Layer Control on Leading- and Trailing-Edge Flaps of a Large-Scale, Low-Aspect-Ratio, 45 Swept-wing Airplane Configuration

NASA Technical Reports Server (NTRS)

Maki, Ralph L.

1959-01-01

Blowing boundary-layer control was applied to the leading- and trailing-edge flaps of a 45 deg sweptback-wing complete model in a full-scale low-speed wind-tunnel study. The principal purpose of the study was to determine the effects of leading-edge flap deflection and boundary-layer control on maximum lift and longitudinal stability. Leading-edge flap deflection alone was sufficient to maintain static longitudinal stability without trailing-edge flaps. However, leading-edge flap blowing was required to maintain longitudinal stability by delaying leading-edge flow separation when trailing-edge flaps were deflected either with or without blowing. Partial-span leading-edge flaps deflected 60 deg with moderate blowing gave the major increase in maximum lift, although higher deflection and additional blowing gave some further increase. Inboard of 0.4 semispan leading-edge flap deflection could be reduced to 40 deg and/or blowing could be omitted with only small loss in maximum lift. Trailing-edge flap lift increments were increased by boundary-layer control for deflections greater than 45 deg. Maximum lift was not increased with deflected trailing-edge flaps with blowing.

The effect of partial-span split flaps on the aerodynamic characteristics of a Clark Y wing

NASA Technical Reports Server (NTRS)

Wenzinger, Carl J

1933-01-01

Aerodynamic force tests were made in the N.A.C.A. 7 by 10 foot wind tunnel on a model Clark Y wing with a 20 percent chord split flap deflected 60 degrees downward. The tests were made to determine the effect of partial-span split flaps, located at various positions along the wing span on the aerodynamic characteristics of the wing-and-flap combination. The different lengths and locations of the flaps were obtained by cutting off portions of a full-span flap, first from the tips and then from the center. The results are given in the form of curves of lift, drag, and center of pressure. They show that with partial-span split flaps both the lift and drag are less than with full-span flaps; that the lift for a given length of flap is somewhat greater when the partial span is located at the center of the wing than when it is located at the tip portion, and that the drag for a given length of flap is the same regardless of the location over the flap with respect to the wing span.

Effect of Krueger nose flaps on the experimental force and moment characteristics of an oblique wing

NASA Technical Reports Server (NTRS)

Hopkins, E. J.; Lovette, G. H.

1976-01-01

Experimental force and moment data are presented for an oblique wing mounted on a body of revolution and equipped with Krueger type nose flaps. The effectiveness of these flaps in making the moment curves more linear by controlling the flow separation on the downstream wing panel at high lift coefficients was determined. The investigation of the effects of the Krueger flaps covered two cases: (1) use of the flaps on the downstream wing panel only and (2) use of the flaps on both wing panels. For part of the tests, the Krueger flaps were mounted on nose flaps that were drooped either 5 deg or 10 deg. The wing was elliptical in planform, had an aspect ratio of 6.0 (based on the unswept span) and was tested at sweep angles of 0, 45 deg, and 50 deg. The Mach-number range covered was from 0.25 to 0.95. It was found that the most effective arrangement of the Krueger flaps for making the pitching-, rolling-, and yawing-moment curves more linear at high lift coefficients was having the Krueger flaps mounted on the nose flaps drooped 5 deg and only on the downstream wing panel.

A standardized model for predicting flap failure using indocyanine green dye

NASA Astrophysics Data System (ADS)

Zimmermann, Terence M.; Moore, Lindsay S.; Warram, Jason M.; Greene, Benjamin J.; Nakhmani, Arie; Korb, Melissa L.; Rosenthal, Eben L.

2016-03-01

Techniques that provide a non-invasive method for evaluation of intraoperative skin flap perfusion are currently available but underutilized. We hypothesize that intraoperative vascular imaging can be used to reliably assess skin flap perfusion and elucidate areas of future necrosis by means of a standardized critical perfusion threshold. Five animal groups (negative controls, n=4; positive controls, n=5; chemotherapy group, n=5; radiation group, n=5; chemoradiation group, n=5) underwent pre-flap treatments two weeks prior to undergoing random pattern dorsal fasciocutaneous flaps with a length to width ratio of 2:1 (3 x 1.5 cm). Flap perfusion was assessed via laser-assisted indocyanine green dye angiography and compared to standard clinical assessment for predictive accuracy of flap necrosis. For estimating flap-failure, clinical prediction achieved a sensitivity of 79.3% and a specificity of 90.5%. When average flap perfusion was more than three standard deviations below the average flap perfusion for the negative control group at the time of the flap procedure (144.3+/-17.05 absolute perfusion units), laser-assisted indocyanine green dye angiography achieved a sensitivity of 81.1% and a specificity of 97.3%. When absolute perfusion units were seven standard deviations below the average flap perfusion for the negative control group, specificity of necrosis prediction was 100%. Quantitative absolute perfusion units can improve specificity for intraoperative prediction of viable tissue. Using this strategy, a positive predictive threshold of flap failure can be standardized for clinical use.

[Reconstruction of ankle and foot with combination of free perforator flaps and skin graft].

PubMed

Yin, Lu; Gong, Ketong; Yin, Zhonggang; Zhang, Bo; Xu, Jianhua

2017-03-01

To evaluate the clinical outcomes of free perforator flaps combined with skin graft for reconstruction of ankle and foot soft tissue defects. Between June 2014 and October 2015, 20 cases of ankle and foot soft tissue defects were treated. There were 16 males and 4 females, aged from 19 to 61 years (mean, 43.3 years). Injury was caused by traffic accident in 7 cases, by crashing in 9 cases, and machine twist in 4 cases. The locations were the ankle in 6 cases, the heel in 3 cases, the dorsum pedis in 4 cases, and the plantar forefoot in 7 cases of avulsion injury after toes amputation. The size of wound ranged from 15 cm×10 cm to 27 cm×18 cm. The time from injury to treatment was from 11 to 52 days (mean, 27 days). The anterolateral thigh perforator flap was used in 11 cases, thoracodorsal antery perforator flap in 3 cases, medial sural artery perforator flap in 4 cases, deep inferior epigastric perforator flap in 1 case, and anteromedial thigh perforator flap in 1 case, including 5 chimeric perforator flaps, 5 polyfoliate perforator flaps, 3 flow-through perforator flaps, and 3 conjoined perforator flaps. The size of the perforator flap ranged from 10.0 cm×6.5 cm to 36.0 cm×8.0 cm, the size of skin graft from 5 cm×3 cm to 18 cm×12 cm. Venous crisis occurred in 2 flaps which survived after symptomatic treatment; 18 flaps survived successfully and skin grafting healed well. The follow-up time ranged 4-18 months (mean, 8.3 months). The flaps had good appearance, texture and color, without infection. The patients could walk normally and do daily activities. Only linear scars were observed at the donor sites. Free perforator flap can be used to reconstruct defects in the ankle and foot, especially in the weight-bearing area of the plantar forefoot. A combination of free perforator flap and skin graft is ideal in reconstruction of great soft tissue defects in the ankle and foot.

The effect of topical minoxidil pretreatment on nonsurgical delay of rat cutaneous flaps: further studies.

PubMed

Gümüş, Nazım; Odemiş, Yusuf; Tuncer, Ersin; Yılmaz, Sarper

2013-08-01

The purpose of this study was to determine the effectiveness of topically applied minoxidil in the pharmacological delay phenomenon and to demonstrate the comparable microscopic and macroscopic changes between minoxidil-pretreated flaps and surgically delayed flaps. A modified version of the McFarlane flap was used. Group 1 rats, in which a caudally based dorsal skin flap was raised and sutured back, were the control group. In group II, minoxidil solution was spread over the marked skin flap area for 7 days. On the 7th day, a caudally based dorsal skin flap was elevated and then sutured back. Group III rats underwent a surgical delay procedure alone. On the 7th day after flap elevation, evaluation was done by histologic examination and calculation of the flap survival areas in all groups. The lowest flap survival rate appeared in group I and was statistically different from groups II and III. The mean surviving skin flap area in the minoxidil-pretreated group was significantly larger than that in the control group. After histologic evaluation, moderate angiogenesis was also detected in group II. We also found that surgical delay significantly reduced flap necrosis when compared to the minoxidil pretreatment group. According to our study, minoxidil may be considered an effective vasoactive agent for the stimulation of angiogenesis in rat cutaneous flaps and capable of achieving pharmacological delay and increasing flap survival. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Efficacy of Liposuction as a Delay Method for Improving Flap Survival.

PubMed

Orhan, Erkan; Erol, Yağmur Reyyan; Deren, Orgun; Altun, Serdar; Erdoğan, Bülent

2016-12-01

Flaps are often used in repairing tissue defects and partial or full flap loss is still an important morbidity cause. Several techniques have been tried to increase flap circulation but none of these could replace the delay technique. Our goal in this study is to show the efficacy of liposuction in delay of dorsal rat cutaneous flaps and improvement in flap survival. Twenty-four Wistar rats were used. The rats in group 1 received 9 × 3-sized caudally-based random pattern skin flaps. In group 2, liposuction was done under the tissue island spotted as the flap and after 14 days, standard flap surgery was done. In group 3, surgical delay was done and after 14 days, standard flap surgery was done. In group 4, liposuction was done under the tissue island spotted as the flap and standard flap surgery was done right after the liposuction. The rate of necrotic tissue in group 3 (surgical delay; mean % 13.7) was less than the rate in group 2 (liposuction delay; mean % 15.1), although the difference was not statistically significant. The necrosis rates in group 3 (surgical delay) and group 2 (liposuction delay) were less than the rates in both group 1 (only flap; mean % 41.5) and group 4 (liposuction flap; mean % 40.0) and this difference was statistically significant (p < 0.0001). Liposuction can be an alternative to surgical delay as a less invasive method in the clinic. This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

[Contribution of the scrotal flap for the coverage of ischial and perineal pressure ulcers].

PubMed

Vantomme, M; Viard, R; Aimard, R; Vincent, P-L; Comparin, J-P; Voulliaume, D

2018-04-11

The ischiatric pressure sore is a common pathology in rehabilitated spinal cord injured people, despite careful prevention. Medical treatment by discharge and directed healing is not always sufficient and surgery using local musculocutaneous flaps is often essential. Unfortunately, recidivism is frequent and the availability of local flaps is limited. The scrotal flap is an excellent complement to classic flaps, gluteal flaps or hamstrings. It can be used alone or in addition to another musculocutaneous flap, in first or second intention. The scrotal flap is a musculocutaneous flap, using the Dartos, the platys muscle of the scrotum. It is richly vascularized, extensible and resistant. Its great plasticity makes it adaptable to any form of loss of substance, with an arc of rotation that can reach the anal margin. It can also be desepidermized and buried to fill a deep defect. Ten cases of scrotal flaps and their different indications are reviewed: some are used in first intention, others in addition to musculocutaneous flaps. The removal of a scrotal flap is fast and extremely easy. The simple closure of the donor site allows the sampling of half of the scrotum due to the great local laxity. The scrotal flaps achieved quickly healed, as well as the donor sites. Only one recurrence was observed after an inappropriate treatment of underlying osteitis. No complications have occurred. The scrotal musculocutaneous flap, reliable, resistant, quick and easy to remove is an excellent means of coverage of the perineal region. It can be used for the treatment of any loss of perineal substance in humans, but remains particularly useful for the treatment of ischial or perineal pressure sores. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Defining the Role of Free Flaps in Partial Breast Reconstruction.

PubMed

Smith, Mark L; Molina, Bianca J; Dayan, Erez; Jablonka, Eric M; Okwali, Michelle; Kim, Julie N; Dayan, Joseph H

2018-03-01

 Free flaps have a well-established role in breast reconstruction after mastectomy; however, their role in partial breast reconstruction remains poorly defined. We reviewed our experience with partial breast reconstruction to better understand indications for free tissue transfer.  A retrospective review was performed of all patients undergoing partial breast reconstruction at our center between February 2009 and October 2015. We evaluated the characteristics of patients who underwent volume displacement procedures versus volume replacement procedures and free versus pedicled flap reconstruction.  There were 78 partial breast reconstructions, with 52 reductions/tissue rearrangements (displacement group) and 26 flaps (replacement group). Bra cup size and body mass index (BMI) were significantly smaller in the replacement group. Fifteen pedicled and 11 free flaps were performed. Most pedicled flaps (80.0%) were used for lateral or upper pole defects. Most free flaps (72.7%) were used for medial and inferior defects or when there was inadequate donor tissue for a pedicled flap. Complications included hematoma, cellulitis, and one aborted pedicled flap.  Free and pedicled flaps are useful for partial breast reconstruction, particularly in breast cancer patients with small breasts undergoing breast-conserving treatment (BCT). Flap selection depends on defect size, location, and donor tissue availability. Medial defects are difficult to reconstruct using pedicled flaps due to arc of rotation and intervening breast tissue. Free tissue transfer can overcome these obstacles. Confirming negative margins before flap reconstruction ensures harvest of adequate volume and avoids later re-operation. Judicious use of free flaps for oncoplastic reconstruction expands the possibility for breast conservation. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

Balancing the Power-to-Load Ratio for a Novel Variable Geometry Wave Energy Converter with Nonideal Power Take-Off in Regular Waves: Preprint

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tom, Nathan M; Yu, Yi-Hsiang; Wright, Alan D

This work attempts to balance power absorption against structural loading for a novel variable geometry wave energy converter. The variable geometry consists of four identical flaps that will be opened in ascending order starting with the flap closest to the seafloor and moving to the free surface. The influence of a pitch motion constraint on power absorption when utilizing a nonideal power take-off (PTO) is examined and found to reduce the losses associated with bidirectional energy flow. The power-to-load ratio is evaluated using pseudo-spectral control to determine the optimum PTO torque based on a multiterm objective function. The pseudo-spectral optimalmore » control problem is extended to include load metrics in the objective function, which may now consist of competing terms. Separate penalty weights are attached to the surge-foundation force and PTO control torque to tune the optimizer performance to emphasize either power absorption or load shedding. PTO efficiency is not included in the objective function, but the penalty weights are utilized to limit the force and torque amplitudes, thereby reducing losses associated with bidirectional energy flow. Results from pseudo-spectral control demonstrate that shedding a portion of the available wave energy can provide greater reductions in structural loads and reactive power.« less

In situ monitoring of surgical flap viability using THz imaging (Conference Presentation)

NASA Astrophysics Data System (ADS)

Bajwa, Neha; Sung, Shijun; Grundfest, Warren; Taylor, Zachary

2016-03-01

This paper explores the utility of reflective THz imaging to assess the viability of surgical flaps. Flap surgery is a technique where tissue is harvested from a donor site and moved to a recipient while keeping the blood supply intact. This technique is common in head and neck tumor resection surgery where the reconstruction of complex and sensitive anatomic structures is routine following the resection of large and/or invasive tumors. Successful flap surgery results in tissue that is sufficiently perfused with both blood and extracellular water. If insufficient fluid levels are maintained, the flap tissue becomes necrotic and must be excised immediately to prevent infection developing and spreading to the surrounding areas. The goal of this work is to investigate the hydration of surgical flaps and correlate image features to successful graft outcomes. Advancement flaps were created on the abdomens of rat models. One rat model was labeled control and care was taken to ensure a successful flap outcome. The flap on the second rat was compromised with restricted blood flow and allowed to fail. The flaps of both rats were imaged once a day over the course of a week at which point the compromised flap had begun to show signs of necrosis. Significant differences in tissue water content were observed between rats over the experimental period. The results suggest that THz imaging may enable early assessment of flap viability.

Use of Autologous Scleral Graft in Ahmed Glaucoma Valve Surgery.

PubMed

Wolf, Alvit; Hod, Yair; Buckman, Gila; Stein, Nili; Geyer, Orna

2016-04-01

To compare the efficacy of an autoscleral free-flap graft versus an autoscleral rotational flap graft in Ahmed glaucoma valve (AGV) surgery. Medical records (2005 to 2012) of 51 consecutive patients (51 eyes) who underwent AGV surgery with the use of either an autoscleral free-flap graft or an autoscleral rotational flap graft to cover the external tube at the limbus were retrieved for review. The main outcome measure was the incidence of tube exposure associated with each surgical approach. Twenty-seven consecutive patients (27 eyes) received a free-flap graft and 24 consecutive patients (24 eyes) received a rotational flap graft. The mean follow-up time was 55.6 ± 18.3 months for the former and 24.2± 5 .0 months for the latter (P<0.0001). Two patients in the free-flap group (8.9%) developed tube exposure at 24 and 55 months postoperatively compared with none of the patients in the rotational flap group. Graft thinning without evidence of conjunctival erosion was observed in 15 patients (55%) in the free-flap group and in 7 patients (29.1%) in the rotational flap group. The use of an autoscleral rotational flap graft is an efficacious technique for primary tube patch grafting in routine AGV surgery, and yielded better results than an autoscleral free-flap graft. Its main advantages over donor graft material are availability and lower cost.

Effect of marking pens on femtosecond laser-assisted flap creation.

PubMed

Ide, Takeshi; Kymionis, George D; Abbey, Ashkan M; Yoo, Sonia H; Culbertson, William W; O'Brien, Terrence P

2009-06-01

To compare the ease of the flap lift after central corneal marking with 2 types of marking pens after femtosecond laser-assisted flap creation in laser in situ keratomileusis. Bascom Palmer Eye Institute, University of Miami, Miami, Florida, USA. Porcine eyes were prepared for flap creation with a femtosecond laser (IntraLase). The eyes were assigned to 1 of 4 groups. After the femtosecond laser treatment, the difficulty of flap lifting the 4 groups was compared. Twelve porcine eyes, 3 in each group, were evaluated. In the 2 groups in which an oil-based pen was used, the corneal flap could not be lifted. In the 2 groups in which a water-based pen was used, the corneal flap was easily lifted. Oil-based ink may reduce the ability of the femtosecond laser to penetrate the cornea. The resultant corneal flap may require aggressive manipulation to be lifted. When used to mark the center of the cornea before flap creation, water-based ink provided greater ease of corneal flap lifting than oil-based ink. Because the marking is located over the center of the pupil, any alteration of the cornea in this area from aggressive flap lifting may result in substantial visual loss. Therefore, the use of an oil-based ink to mark the central cornea must be avoided to prevent traumatic irregularities of the flap stroma.

Double transverse myocutaneous gracilis free flaps for unilateral breast reconstruction.

PubMed

Werdin, Frank; Haug, Daniel M; Amr, Amro; Schoeller, Thomas

2016-10-01

In cases were the deep inferior epigastric perforator flap (DIEP flap) is not available and unilateral transverse myocutaneous gracilis flap (TMG flap) is not sufficient for breast reconstruction, we perform double TMG flaps as a reconstructive method. In this report, we present our results of the use of double TMG free-flap-transfer for unilateral breast reconstruction. Between August 2004 and June 2012 we performed 58 TMG flaps in 29 patients for unilateral breast reconstruction. Patient data were analyzed and operative outcome (operation time, complication rate and aesthetic results) were investigated. Aesthetic outcome was evaluated retrospectively via photo documentation by an independent plastic surgeon. The results were classified in;unsatisfactory, satisfactory, good and very good. The average operating time was 6 hours 55 minutes (295 - 650 minutes). Of 58 TMG flaps, 57 (98.3%) were successful. Thrombosis occurred in seven (12%) cases (1 arterial, 6 venous). Flap salvage was successful in six cases and flap failure occurred in one (1.7%) case. The results of 25 patients were graded as good and very good. Three patients showed satisfying and one patient unsatisfying results. Double TMG flaps in unilateral breast reconstruction could lead to good operative results. This method further expands the range of options with autologous tissue in reconstructive breast surgery. © 2015 Wiley Periodicals, Inc. Microsurgery 36:539-545, 2016. © 2015 Wiley Periodicals, Inc.

Instep island flaps.

PubMed

Reading, G

1984-12-01

The instep island flap is safe and useful. It is based on branches of the posterior tibial artery and can be a musculocutaneous or a direct fasciocutaneous island flap. Sensory branches of the digital nerves may be transposed with the flap. There is a wide arc of transposition and the flap has survived even in very difficult circumstances.

Comparative study of functional and aesthetically outcomes of reverse digital artery and reverse dorsal homodigital island flaps for fingertip repair.

PubMed

Chen, Q Z; Sun, Y C; Chen, J; Kong, J; Gong, Y P; Mao, T

2015-11-01

This retrospective study was designed to compare functional and cosmetic outcomes of the reverse digital artery island flap and reverse dorsal homodigital island flap in fingertip repair. A total of 23 patients were followed for 24 to 30 months. The reverse digital artery island flap was used in 12 patients, and reverse dorsal homodigital island flap in another 11 patients. Flap sensibility was assessed using the Semmes-Weinstein monofilament test and static 2-point discrimination test. Patient satisfaction, active motion of the finger joints, complications and cold intolerance were evaluated. The static 2-point discrimination and Michigan Hand Outcomes Questionnaire (appearance) of the fingers treated with a reverse digital artery flap were significantly better than those with a reverse dorsal homodigital flap. The static 2-point discrimination of the skin-grafted donor sides after dorsal homodigital flap were poorer than that in the contralateral finger. No significant differences were found between the two flaps for pressure or touch sensibility, active ranges of digital motion, complications and cold intolerance. III. © The Author(s) 2015.

Dorsal Intercostal Artery Perforator Propeller Flaps: A Reliable Option in Reconstruction of Large Meningomyelocele Defects.

PubMed

Basterzi, Yavuz; Tenekeci, Goktekin

2016-04-01

Several options have been reported for the reconstruction of myelomeningocele defects. In this article, we present our experience on soft tissue reconstruction of myelomeningocele defects by using island propeller dorsal intercostal artery perforator (DIAP) flaps. Between January 2008 and February 2014, all newborns with large myelomeningocele defects (13 newborns) were reconstructed with island propeller DIAP flaps. All flaps survived completely. In 8 patients out of 13, venous insufficiency was observed which then resolved spontaneously. Flap donor sites were closed primarily. Myelomeningocele defects with a diameter larger than 5 cm require reconstruction with flaps. To mobilize a well-vascularized tissue over the defect without tension in which the suture lines will not overlap over the midline where the dura is repaired and over the meninges is one of the goals of reconstruction for such defects. Perforator propeller flaps enable us to reach those goals. Use of perforator flaps provides 2 important advantages, namely, more predictability and also more freedom in mobilizing flaps toward the defect. This study proves the reliability of DIAP propeller flaps in the reconstruction of myelomeningocele defects.

Biochemical analyses indicate that binding and cleavage specificities define the ordered processing of human Okazaki fragments by Dna2 and FEN1.

PubMed

Gloor, Jason W; Balakrishnan, Lata; Campbell, Judith L; Bambara, Robert A

2012-08-01

In eukaryotic Okazaki fragment processing, the RNA primer is displaced into a single-stranded flap prior to removal. Evidence suggests that some flaps become long before they are cleaved, and that this cleavage involves the sequential action of two nucleases. Strand displacement characteristics of the polymerase show that a short gap precedes the flap during synthesis. Using biochemical techniques, binding and cleavage assays presented here indicate that when the flap is ∼ 30 nt long the nuclease Dna2 can bind with high affinity to the flap and downstream double strand and begin cleavage. When the polymerase idles or dissociates the Dna2 can reorient for additional contacts with the upstream primer region, allowing the nuclease to remain stably bound as the flap is further shortened. The DNA can then equilibrate to a double flap that can bind Dna2 and flap endonuclease (FEN1) simultaneously. When Dna2 shortens the flap even more, FEN1 can displace the Dna2 and cleave at the flap base to make a nick for ligation.

[Modified pectoralis major myocutaneous flap in reconstruction of head and neck defects].

PubMed

Chen, Jie; Huang, Wenxiao; Li, Zan; Zhou, Xiao; Yu, Jianjun; Bao, Ronghua; Zhang, Hailin; Ling, Hang

2015-05-01

To report the experience of use of modified pectoralis major myocutaneous (PMMC) flaps in reconstruction of head and neck postoperative defects. A total of 107 patients who underwent head and neck defect reconstruction using modified PMMC flaps after tumor rescetion between Jan 2008 and Dec 2013 were analyzed retrospectively. The success rate of reconstruction with modified PMMC flaps was 94.4% (101/107). Five patients had partial flap necrosis and their wounds healed with dressing change. One patient (0.9%) had total flap necrosis, followed by the second reconstruction using contralateral PMMC flap. The modified falcate PMMC flap can obtain optimum quantity of the skin in the chest and decreasing the closing tension of the donnor site in favor of wound healing. The pedicle without muscle will not only maintain the partial function of the pectoralis major, but also help to avoid pressing the vascular pedicle within the subclavian tunnel. The muscular element the pedicled muscles of the PMMC flap can increase the ability of the flap to resist infection, which can use for covering an exposed carotid artery and improving the neck fibrosis of irradiated patients.

Optimal propulsive flapping in Stokes flows.

PubMed

Was, Loïc; Lauga, Eric

2014-03-01

Swimming fish and flying insects use the flapping of fins and wings to generate thrust. In contrast, microscopic organisms typically deform their appendages in a wavelike fashion. Since a flapping motion with two degrees of freedom is able, in theory, to produce net forces from a time-periodic actuation at all Reynolds numbers, we compute in this paper the optimal flapping kinematics of a rigid spheroid in a Stokes flow. The hydrodynamics for the force generation and energetics of the flapping motion is solved exactly. We then compute analytically the gradient of a flapping efficiency in the space of all flapping gaits and employ it to derive numerically the optimal flapping kinematics as a function of the shape of the flapper and the amplitude of the motion. The kinematics of optimal flapping are observed to depend weakly on the flapper shape and are very similar to the figure-eight motion observed in the motion of insect wings. Our results suggest that flapping could be a exploited experimentally as a propulsion mechanism valid across the whole range of Reynolds numbers.

Management of Dropped Skull Flaps.

PubMed

Abdelfatah, Mohamed AbdelRahman

2017-01-01

Dropping a skull flap on the floor is an uncommon and avoidable mistake in the neurosurgical operating theater. This study retrospectively reviewed all incidents of dropped skull flaps in Ain-Shams University hospitals during a 10-year period to show how to manage this problem and its outcome. Thirty-one incidents of dropped skull flaps occurred from January 2004 to January 2014 out of more than 10,000 craniotomies. Follow-up period varied from 20 to 44 months. The bone flap was dropped while elevating the bone (n = 16), while drilling the bone on the operating table (n = 5), and during insertion of the bone flap (n = 10). Treatment included re-insertion of the skull flap after soaking it in povidone iodine and antibiotic solution (n = 17) or after autoclaving (n = 11), or discarding the skull flap and replacing it with a mesh cranioplasty in the same operation (n = 3). No bone or wound infection was noted during the follow-up period. Management of dropped skull flap is its prevention. Replacement of the skull flap, after decontamination, is an option that avoids the expense and time of cranioplasty.

Near-Infrared Irradiation Increases Length of Axial Pattern Flap Survival in Rats.

PubMed

Yasunaga, Yoshichika; Matsuo, Kiyoshi; Tanaka, Yohei; Yuzuriha, Shunsuke

2017-01-01

Objective: We previously reported that near-infrared irradiation nonthermally induces long-lasting vasodilation of the subdermal plexus by causing apoptosis of vascular smooth muscle cells. To clarify the possible application of near-infrared irradiation to prevent skin flap necrosis, we evaluated the length of axial pattern flap survival in rats by near-infrared irradiation. Methods: A bilaterally symmetric island skin flap was elevated under the panniculus carnosus on the rat dorsum. Half of the flap was subjected to near-infrared irradiation just before flap elevation with a device that simulates solar radiation, which has a specialized contact cooling apparatus to avoid thermal effects. The length of flap survival of the near-infrared irradiated side was measured 7 days after flap elevation and compared with the nonirradiated side. Results: The irradiated side showed elongation of flap survival compared with the nonirradiated side (73.3 ± 11.7 mm vs 67.3 ± 14.9 mm, respectively, P = .03). Conclusions: Near-infrared irradiation increases the survival length of axial pattern flaps in rats.

Vortex leading edge flap assembly for supersonic airplanes

NASA Technical Reports Server (NTRS)

Rudolph, Peter K. C. (Inventor)

1997-01-01

A leading edge flap (16) for supersonic transport airplanes is disclosed. In its stowed position, the leading edge flap forms the lower surface of the wing leading edge up to the horizontal center of the leading edge radius. For low speed operation, the vortex leading edge flap moves forward and rotates down. The upward curve of the flap leading edge triggers flow separation on the flap and rotational flow on the upper surface of the flap (vortex). The rounded shape of the upper fixed leading edge provides the conditions for a controlled reattachment of the flow on the upper wing surface and therefore a stable vortex. The vortex generates lift and a nose-up pitching moment. This improves maximum lift at low speed, reduces attitude for a given lift coefficient and improves lift to drag ratio. The mechanism (27) to move the vortex flap consists of two spanwise supports (24) with two diverging straight tracks (64 and 68) each and a screw drive mechanism (62) in the center of the flap panel (29). The flap motion is essentially normal to the airloads and therefore requires only low actuation forces.

Preparation and Thickness Profile of Endothelial Keratoplasty Lenticules from Donated Whole Eyes with Previous Photorefractive Keratectomy

PubMed Central

Kanavi, Mozhgan Rezaei; Fahim, Pejman; Rahmanian, Mohsen; Chamani, Tahereh; Kheiri, Bahar; Balagholi, Sahar; Javadi, Mohammad Ali

2017-01-01

Purpose: To describe the preparation and thickness profiles of endothelial keratoplasty lenticules harvested from eyes with previous photorefractive keratectomy (PRK). Methods: Donor whole eyes that underwent PRK were subjected to microkeratome-assisted dissection for Descemet stripping automated endothelial keratoplasty. Specular microscopy and Visante optical coherence tomography were performed on precut corneas. Endothelial cell indices and thickness profiles of endothelial keratoplasty lenticules were statistically analyzed. Postoperative reports for transplanted lenticules were recorded. Results: Over a 6-month period, 2,929 whole eyes from 1,471 donors were screened for PRK. Twenty-five (0.85%) eyes from 14 donors were diagnosed with disciform haziness due to prior PRK and were used uneventfully for preparation of endothelial keratoplasty lenticules. Mean endothelial cell count was 3164.6 ± 311.0/mm2 and mean central posterior lenticule thickness was 128 ± 34 μm. Posterior lenticules revealed an increase in thickness from the central to peripheral cornea (mean increase of 26.2 μm at pericentral and 90.4 μm at peripheral locations). Mean increase in thickness was statistically different between two peripheral locations (74.5 μm vs. 108.1 μm, P = 0.047). Postoperative reports of transplanted lenticules revealed no posterior flap detachment or loss of clarity at least three months after the surgery. Conclusion: PRK donor whole eyes are potential sources for preparation of microkeratome-assisted thin endothelial keratoplasty lenticules with a high endothelial cell count. Although an asymmetric and significant increase in thickness was present at the peripheral cornea, neither attachment nor clarity of transplanted lenticules was affected by variations in thickness of precut corneas. PMID:29090046

Biomimetic Beetle-Inspired Flapping Air Vehicle Actuated by Ionic Polymer-Metal Composite Actuator

PubMed Central

Zhao, Yang; Xu, Di; Sheng, Jiazheng; Meng, Qinglong; Wu, Dezhi; Wang, Lingyun; Xiao, Jingjing; Lv, Wenlong; Sun, Daoheng

2018-01-01

During the last decades, the ionic polymer-metal composite (IPMC) received much attention because of its potential capabilities, such as large displacement and flexible bending actuation. In this paper, a biomimetic flapping air vehicle was proposed by combining the superiority of ionic polymer metal composite with the bionic beetle flapping principle. The blocking force was compared between casted IPMC and IPMC. The flapping state of the wing was investigated and the maximum displacement and flapping angle were measured. The flapping displacement under different voltage and frequency was tested. The flapping displacement of the wing and the support reaction force were measured under different frequency by experiments. The experimental results indicate that the high voltage and low frequency would get large flapping displacement. PMID:29682006

Noise Reduction of Aircraft Flap

NASA Technical Reports Server (NTRS)

Hutcheson, Florence V. (Inventor); Brooks, Thomas F. (Inventor)

2009-01-01

A reduction in noise radiating from a side of a deployed aircraft flap is achieved by locating a slot adjacent the side of the flap, and then forcing air out through the slot with a suitable mechanism. One, two or even three or more slots are possible, where the slot is located at one;or more locations selected from a group of locations comprising a top surface of the flap, a bottom surface of the flap, an intersection of the top and side surface of the flap, an intersection of the bottom and side surfaces of the flap, and a side surface of the flap. In at least one embodiment the slot is substantially rectangular. A device for adjusting a rate of the air forced out through the slot can also be provided.

Vulva reconstruction after pelvic exenteration, using a unique combination of two flaps

PubMed Central

van Bommel, Annelotte C M; Schreuder, Henk W R; Schellekens, Pascal P A

2011-01-01

A 64-year-old woman with recurrence of carcinoma of the vulva in an irradiated area received an en-bloc total pelvic exenteration. Reconstruction of the pelvic defect was performed with an anterolateral thigh (ALT) flap and a rectus abdominis muscle (RAM) flap (PM/RAM). This combination of flaps is unique, with excellent results. In a large defect, often irradiated in advance, well-vascularised tissue should be placed. Multiple flaps can be used to reconstruct these large pelvic defects, each with their own advantages and disadvantages. The combination of flaps used in this case uses the good properties of both flaps: the reliable and well-vascularised PM/RAM in combination with the ALT flap to provide much bulk in extreme large defects. PMID:22692483