Science.gov

Sample records for 5-lo-activating protein flap

  1. Role of the 5-Lipoxygenase–activating Protein (FLAP) in Murine Acute Inflammatory Responses

    PubMed Central

    Byrum, Robert S.; Goulet, Jennifer L.; Griffiths, Richard J.; Koller, Beverly H.

    1997-01-01

    Leukotrienes are potent inflammatory mediators synthesized from arachidonic acid (AA) predominately by cells of myeloid origin. The synthesis of these lipids is believed to be dependent not only on the expression of the enzyme 5-lipoxygenase (5-LO), which catalyzes the first steps in the synthesis of leukotrienes, but also on expression of a nuclear membrane protein termed the 5-LO–activating protein (FLAP). To study the relationship of these two proteins in mediating the production of leukotrienes in vivo and to determine whether the membrane protein FLAP has additional functions in various inflammatory processes, we have generated a mouse line deficient in this protein. FLAP-deficient mice develop normally and are healthy. However, an array of assays comparing inflammatory reactions in FLAP-deficient mice and in normal controls revealed that FLAP plays a role in a subset of these reactions. Although examination of DTH and IgE-mediated passive anaphylaxis showed no difference between wild-type and FLAP-deficient animals, mice without FLAP possessed a blunted inflammatory response to topical AA and had increased resistance to platelet-activating factor–induced shock compared to controls. Also, edema associated with Zymosan A–induced peritonitis was markedly reduced in animals lacking FLAP. To determine whether these differences relate solely to a deficit in leukotriene production, or whether they reflect an additional role for FLAP in inflammation, we compared the FLAP-deficient mice to 5-LO–deficient animals. Evaluation of mice lacking FLAP and 5-LO indicated that production of leukotrienes during inflammatory responses is dependent upon the availability of FLAP and did not support additional functions for FLAP beyond its role in leukotriene production. PMID:9091580

  2. DNA and Protein Requirements for Substrate Conformational Changes Necessary for Human Flap Endonuclease-1-catalyzed Reaction.

    PubMed

    Algasaier, Sana I; Exell, Jack C; Bennet, Ian A; Thompson, Mark J; Gotham, Victoria J B; Shaw, Steven J; Craggs, Timothy D; Finger, L David; Grasby, Jane A

    2016-04-08

    Human flap endonuclease-1 (hFEN1) catalyzes the essential removal of single-stranded flaps arising at DNA junctions during replication and repair processes. hFEN1 biological function must be precisely controlled, and consequently, the protein relies on a combination of protein and substrate conformational changes as a prerequisite for reaction. These include substrate bending at the duplex-duplex junction and transfer of unpaired reacting duplex end into the active site. When present, 5'-flaps are thought to thread under the helical cap, limiting reaction to flaps with free 5'-terminiin vivo Here we monitored DNA bending by FRET and DNA unpairing using 2-aminopurine exciton pair CD to determine the DNA and protein requirements for these substrate conformational changes. Binding of DNA to hFEN1 in a bent conformation occurred independently of 5'-flap accommodation and did not require active site metal ions or the presence of conserved active site residues. More stringent requirements exist for transfer of the substrate to the active site. Placement of the scissile phosphate diester in the active site required the presence of divalent metal ions, a free 5'-flap (if present), a Watson-Crick base pair at the terminus of the reacting duplex, and the intact secondary structure of the enzyme helical cap. Optimal positioning of the scissile phosphate additionally required active site conserved residues Tyr(40), Asp(181), and Arg(100)and a reacting duplex 5'-phosphate. These studies suggest a FEN1 reaction mechanism where junctions are bound and 5'-flaps are threaded (when present), and finally the substrate is transferred onto active site metals initiating cleavage.

  3. Prefabrication of vascularized bone flap induced by recombinant human bone morphogenetic protein 2 (rhBMP-2).

    PubMed

    Alam, M I; Asahina, I; Seto, I; Oda, M; Enomoto, S

    2003-10-01

    An experimental model for the prefabrication of a vascularized bone flap was developed in this study. To form vascularized bone in the desired configuration and to increase the survival rate of the grafted bone, a muscle vascularized pedicle (MVP) was transformed into vascularized bone by the inducer recombinant human bone morphogenetic protein 2 (rhBMP-2). The muscle flap (8 x 8 mm) raised on saphenous vessels in the rat thigh was sandwiched between same-size collagen (Terudermis) sheets in the presence or absence of impregnated 25 microg of rhBMP-2 for the experimental group and the control group, respectively. The flaps were harvested 1, 2 and 3 weeks postoperatively. Bone transformation was detected by gross examination, radiology, and histologic testing. No evidence of muscle tissue transformation was found in control flaps, whereas all of the experimental flaps produced new bone. Saphenous vessels were observed to supply the new bone upon harvesting, and the newly formed vascularized bone showed good configuration with shape of the Terudermis sheet. This study indicates that this model of effective bone reconstruction could be potentially applied in a therapeutic setting.

  4. The Effect of Activated Protein C on Attenuation of Ischemia-Reperfusion Injury in a Rat Muscle Flap Model.

    PubMed

    Zhang, Elizabeth W; Fang, Taolin; Arnold, Peter B; Songcharoen, Somjade Jay; Lineaweaver, William C; Zhang, Feng

    2015-10-01

    Ischemia-reperfusion injury is often the final and irreversible factor causing flap failure in microsurgery. The salvage of a microsurgical flap with an ischemia-reperfusion injury contributes to the success of microsurgical flap transfers. Activated protein C (APC), a serine protease with anticoagulant and anti-inflammatory activities, has been shown to improve ischemic flap survival. To date, APC has yet to be applied to models of free flap with ischemia-reperfusion injury. In this study, we aimed to investigate the effect of APC on gracilis flap ischemia-reperfusion injury induced by gracilis vessels clamping and reopening. Sixty male Sprague-Dawley rats were randomly divided into 2 groups. After 4 hours of clamping for ischemia, flaps were reperfused and recombinant human APC (25 μg/kg) or saline was injected in the flaps through pedicles. At 0, 1, 4, 18, and 24 hours after injection (n = 6 for each time point), the tissue samples were harvested. The muscle viability at 24 hours in saline group was 54.8% (15.1%), whereas the APC-treated group was 90.0% (4.3%) (P < 0.05). The induced nitric oxide synthase (iNOS) mRNA expression increased with the time after reperfusion, which were 0.93 (0.25) to 2.09 (0.22) in saline group, and 0.197 (0.15) to 0.711 (0.15) in the APC-treated group. iNOS mRNA expression in the APC-treated group was significantly higher than the saline group at 1, 18, and 24 hours (P < 0.05). Numerous inflammatory cells were observed infiltrating and invading the muscle fibers in the saline group more than the APC-treated group. Increased number of polymorphonuclear cells was also noted in the saline group compared with the APC-treated group (P < 0.05). In conclusion, APC treatment can significantly attenuate ischemia-reperfusion injury and increase the survival of the free flap through down-regulating iNOS mRNA expression and reducing the inflammatory cells. Further research is still needed to be done on various mechanisms in which APC is

  5. A Novel 5-Lipoxygenase-Activating Protein Inhibitor, AM679, Reduces Inflammation in the Respiratory Syncytial Virus-Infected Mouse Eye▿

    PubMed Central

    Musiyenko, Alla; Correa, Lucia; Stock, Nicholas; Hutchinson, John H.; Lorrain, Daniel S.; Bain, Gretchen; Evans, Jilly F.; Barik, Sailen

    2009-01-01

    Respiratory syncytial virus (RSV) is an important cause of viral respiratory disease in children, and RSV bronchiolitis has been associated with the development of asthma in childhood. RSV spreads from the eye and nose to the human respiratory tract. Correlative studies of humans and direct infection studies of BALB/c mice have established the eye as a significant pathway of entry of RSV to the lung. At the same time, RSV infection of the eye produces symptoms resembling allergic conjunctivitis. Cysteinyl leukotrienes (CysLTs) are known promoters of allergy and inflammation, and the first step in their biogenesis from arachidonic acid is catalyzed by 5-lipoxygenase (5-LO) in concert with the 5-LO-activating protein (FLAP). We have recently developed a novel compound, AM679, which is a topically applied and potent inhibitor of FLAP. Here we show with the BALB/c mouse eye RSV infection model that AM679 markedly reduced the RSV-driven ocular pathology as well as the synthesis of CysLTs in the eye. In addition, AM679 decreased the production of the Th2 cell cytokine interleukin-4 but did not increase the viral load in the eye or the lung. These results suggest that FLAP inhibitors may be therapeutic for RSV-driven eye disease and possibly other inflammatory eye indications. PMID:19759251

  6. Effect of microbial transglutaminase and non-meat proteins on functional properties of low NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was aimed at developing value-added low sodium chloride (NaCl), phosphate-free restructured patties using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase, 0.7%) and non-meat proteins (isolated soy protein, ISP and whey protein...

  7. Use of microbial transglutaminase and non-meat proteins to improve functional properties of low NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was aimed at developing a value-added low sodium chloride (NaCl), phosphate-free patty using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase) and non-meat proteins (isolated soy protein, ISP and whey protein concentrate, WPC) ...

  8. Novel Injury Site Targeted Fusion Protein Comprising Annexin V and Kunitz Inhibitor Domains Ameliorates Ischemia-Reperfusion Injury and Promotes Survival of Ischemic Rat Abdominal Skin Flaps.

    PubMed

    Shyu, Victor Bong-Hang; Hsu, Chung En; Wen, Chih-Jen; Wun, Tze-Chein; Tang, Rui; Achilefu, Samuel; Wei, Fu-Chan; Cheng, Hui-Yun

    2017-03-01

    Appropriate antithrombotic therapy is critical for successful outcomes in reconstructive microsurgical procedures involving free tissue transfer. The annexin V-6L15 (ANV-6L15) fusion protein was developed as a targeted antithrombotic reagent. Annexin V specifically binds to exposed phosphatidylserine on apoptotic or injured cells, and prevents coagulation and cell adhesion, whereas 6L15 inhibits tissue factor-VIIa pathway within the coagulation cascade. The treatment efficacy of ANV-6L15 on rat island muscle and pedicled abdominal fasciocutaneous flaps following ischemic injury and ischemia-reperfusion injury (IRI) was evaluated.

  9. Effect of microbial transglutaminase and non-meat proteins on functional properties of low NaCl, phosphate-free patties made from channel catfish (Ictalurus punctatus) belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study was focused on developing value-added low sodium chloride (NaCl), phosphate-free restructured patties using minced channel catfish (Ictalurus punctatus) belly flap meat. The effect of microbial transglutaminase (MTGase, 0.7%) and non-meat proteins (isolated soy protein, ISP and whey prote...

  10. The submental island flap.

    PubMed

    Sterne, G D; Januszkiewicz, J S; Hall, P N; Bardsley, A F

    1996-03-01

    The submental island flap is a reliable source of skin of excellent colour, contour and texture match for facial resurfacing and leaves a well hidden donor site. The flap is safe, rapid and simple to raise. We report on its use in 12 cases of facial or intraoral reconstruction. Complications were few. However, there was one case of complete flap loss following its use in a reverse flow manner, due to the presence of an unreported, but constant, valve in the venous system of the face. We believe this flap to be a worthwhile addition to the existing surgical armamentarium.

  11. The sternocleidomastoid perforator flap.

    PubMed

    Avery, C M E

    2011-10-01

    The conventional pedicled sternocleidomastoid (SCM) flap has a poor arc of rotation, limited volume and precarious vascularity. This report describes a new technique for raising a SCM flap based on the perforating vessels of the superior thyroid vascular pedicle. The upper and lower attachments of the sternocleidomastoid muscle are divided. Four medically and/or surgically compromised patients have successfully undergone reconstruction of hemiglossectomy (1), partial glossectomy (1) and rim of mandible (2) defects for malignancy. The arc of rotation of the SCM flap is greatly increased and the potential applications for the flap expanded.

  12. A study of the blown flap/jet flap analogy

    NASA Technical Reports Server (NTRS)

    Hough, G. R.

    1979-01-01

    A study of the blown flap/jet flap analogy has been undertaken. Analytical predictions were made using both improved lifting line and optimized vortex lattice models for the jet flap. Results were compared with experimental data for three propulsive lift systems; the jet augmented flap, the externally blown flap, and the upper surface blown flap. Force increments due to changes in geometry and jet parameters were well approximated in most cases, although the absolute values of the aerodynamic forces were usually underestimated. The relatively simple jet-flap models gave performance predictions of accuracy comparable to more complex analyses.

  13. Flapping of Insectile Wings

    NASA Astrophysics Data System (ADS)

    Huang, Yangyang; Kanso, Eva

    2015-11-01

    Insects use flight muscles attached at the base of the wings to produce impressive wing flapping frequencies. Yet the effects of muscle stiffness on the performance of insect wings remain unclear. Here, we construct an insectile wing model, consisting of two rigid wings connected at their base by an elastic torsional spring and submerged in an oscillatory flow. The wing system is free to rotate and flap. We first explore the extent to which the flyer can withstand roll perturbations, then study its flapping behavior and performance as a function of spring stiffness. We find an optimal range of spring stiffness that results in large flapping amplitudes, high force generation and good storage of elastic energy. We conclude by conjecturing that insects may select and adjust the muscle spring stiffness to achieve desired movement. These findings may have significant implications on the design principles of wings in micro air-vehicles.

  14. Control of Flap Vortices

    NASA Technical Reports Server (NTRS)

    Greenblatt, David

    2005-01-01

    A wind tunnel investigation was carried out on a semi-span wing model to assess the feasibility of controlling vortices emanating from outboard flaps and tip-flaps by actively varying the degree of boundary layer separation. Separation was varied by means of perturbations produced from segmented zero-efflux oscillatory blowing slots, while estimates of span loadings and vortex sheet strengths were obtained by integrating wing surface pressures. These estimates were used as input to inviscid rollup relations as a means of predicting changes to the vortex characteristics resulting from the perturbations. Surveys of flow in the wake of the outboard and tip-flaps were made using a seven-hole probe, from which the vortex characteristics were directly deduced. Varying the degree of separation had a marked effect on vortex location, strength, tangential velocity, axial velocity and size for both outboard and tip-flaps. Qualitative changes in vortex characteristics were well predicted by the inviscid rollup relations, while the failure to account for viscosity was presumed to be the main reason for observed discrepancies. Introducing perturbations near the outboard flap-edges or on the tip-flap exerted significant control over vortices while producing negligible lift excursions.

  15. Genomic and protein expression analysis reveals flap endonuclease 1 (FEN1) as a key biomarker in breast and ovarian cancer.

    PubMed

    Abdel-Fatah, Tarek M A; Russell, Roslin; Albarakati, Nada; Maloney, David J; Dorjsuren, Dorjbal; Rueda, Oscar M; Moseley, Paul; Mohan, Vivek; Sun, Hongmao; Abbotts, Rachel; Mukherjee, Abhik; Agarwal, Devika; Illuzzi, Jennifer L; Jadhav, Ajit; Simeonov, Anton; Ball, Graham; Chan, Stephen; Caldas, Carlos; Ellis, Ian O; Wilson, David M; Madhusudan, Srinivasan

    2014-10-01

    FEN1 has key roles in Okazaki fragment maturation during replication, long patch base excision repair, rescue of stalled replication forks, maintenance of telomere stability and apoptosis. FEN1 may be dysregulated in breast and ovarian cancers and have clinicopathological significance in patients. We comprehensively investigated FEN1 mRNA expression in multiple cohorts of breast cancer [training set (128), test set (249), external validation (1952)]. FEN1 protein expression was evaluated in 568 oestrogen receptor (ER) negative breast cancers, 894 ER positive breast cancers and 156 ovarian epithelial cancers. FEN1 mRNA overexpression was highly significantly associated with high grade (p = 4.89 × 10(-57)), high mitotic index (p = 5.25 × 10(-28)), pleomorphism (p = 6.31 × 10(-19)), ER negative (p = 9.02 × 10(-35)), PR negative (p = 9.24 × 10(-24)), triple negative phenotype (p = 6.67 × 10(-21)), PAM50.Her2 (p = 5.19 × 10(-13)), PAM50. Basal (p = 2.7 × 10(-41)), PAM50.LumB (p = 1.56 × 10(-26)), integrative molecular cluster 1 (intClust.1) (p = 7.47 × 10(-12)), intClust.5 (p = 4.05 × 10(-12)) and intClust. 10 (p = 7.59 × 10(-38)) breast cancers. FEN1 mRNA overexpression is associated with poor breast cancer specific survival in univariate (p = 4.4 × 10(-16)) and multivariate analysis (p = 9.19 × 10(-7)). At the protein level, in ER positive tumours, FEN1 overexpression remains significantly linked to high grade, high mitotic index and pleomorphism (ps < 0.01). In ER negative tumours, high FEN1 is significantly associated with pleomorphism, tumour type, lymphovascular invasion, triple negative phenotype, EGFR and HER2 expression (ps < 0.05). In ER positive as well as in ER negative tumours, FEN1 protein overexpression is associated with poor survival in univariate and multivariate analysis (ps < 0.01). In ovarian epithelial cancers, similarly, FEN1 overexpression is associated with high grade, high stage and poor survival (ps < 0.05). We conclude that FEN1

  16. Blowing Flap Experiment: PIV Measurements

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Stead, Daniel J.; Bremmer, David M.

    2004-01-01

    PIV measurements of the flow in the region of a flap side edge are presented for several 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 flap vortex system. It is concluded that blowing from the top or bottom surfaces of the flap may lead to a reduction of flap side edge noise.

  17. 5-Lipoxygenase-activating protein (FLAP) inhibitors. Part 4: development of 3-[3-tert-butylsulfanyl-1-[4-(6-ethoxypyridin-3-yl)benzyl]-5-(5-methylpyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethylpropionic acid (AM803), a potent, oral, once daily FLAP inhibitor.

    PubMed

    Stock, Nicholas S; Bain, Gretchen; Zunic, Jasmine; Li, Yiwei; Ziff, Jeannie; Roppe, Jeffrey; Santini, Angelina; Darlington, Janice; Prodanovich, Pat; King, Christopher D; Baccei, Christopher; Lee, Catherine; Rong, Haojing; Chapman, Charles; Broadhead, Alex; Lorrain, Dan; Correa, Lucia; Hutchinson, John H; Evans, Jilly F; Prasit, Peppi

    2011-12-08

    The potent 5-lipoxygenase-activating protein (FLAP) inhibitor 3-[3-tert-butylsulfanyl-1-[4-(6-ethoxypyridin-3-yl)benzyl]-5-(5-methylpyridin-2-ylmethoxy)-1H-indol-2-yl]-2,2-dimethylpropionic acid 11cc is described (AM803, now GSK2190915). Building upon AM103 (1) (Hutchinson et al. J. Med Chem.2009, 52, 5803-5815; Stock et al. Bioorg. Med. Chem. Lett. 2010, 20, 213-217; Stock et al. Bioorg. Med. Chem. Lett.2010, 20, 4598-4601), SAR studies centering around the pyridine moiety led to the discovery of compounds that exhibit significantly increased potency in a human whole blood assay measuring LTB(4) inhibition with longer drug preincubation times (15 min vs 5 h). Further studies identified 11cc with a potency of 2.9 nM in FLAP binding, an IC(50) of 76 nM for inhibition of LTB(4) in human blood (5 h incubation) and excellent preclinical toxicology and pharmacokinetics in rat and dog. 11cc also demonstrated an extended pharmacodynamic effect in a rodent bronchoalveolar lavage (BAL) model. This compound has successfully completed phase 1 clinical studies in healthy volunteers and is currently undergoing phase 2 trials in asthmatic patients.

  18. The saphenous neurovascular free flap.

    PubMed

    Acland, R D; Schusterman, M; Godina, M; Eder, E; Taylor, G I; Carlisle, I

    1981-06-01

    A new neurovascular free-flap donor area on the medial side of the knee is described. The flap is supplied by the saphenous artery, a branch of the descending genicular artery. It is drained both by the long saphenous vein and by the saphenous venae comitantes. Its nerve supply is from the medial femoral cutaneous nerve above the knee and the saphenous nerve below the knee. The flap is thin, has a long vascular pedicle (up to 15 cm) and a dependable nerve supply, and can be made quite large. The principal disadvantage is the donor wound, which requires grafting in most cases. We describe the anatomy of the saphenous flap, the method of raising it, and our early clinical experience with it both as a free flap and as a pedicled flap. Potential uses of the saphenous flap and its broader significance in relation to flaps on the lower extremity are briefly discussed.

  19. Externally blown flap impingement noise

    NASA Technical Reports Server (NTRS)

    Lasagna, P. L.; Putnam, T. W.

    1972-01-01

    Tests of the noise produced by the impingement of the jet exhaust on the wing and flap for an externally blown flap system were conducted with a CF700 turbofan engine and an F-111B wing panel. The noise produced with a daisy nozzle installed on the engine was greater than that produced by a conical nozzle at the same thrust. The presence of the wing next to the test nozzles increased the noise, as did increasing the flap deflection angle. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested. Tests showed that the single-slotted flap deflected 60 deg, produced less noise than the double-slotted flaps. Also, maintaining the maximum distance between the exit nozzle and flap system resulted in a minor reduction in noise.

  20. Bilobed flap in sole surgery

    SciTech Connect

    Sanchez-Conejo-Mir, J.; Bueno Montes, J.; Moreno Gimenez, J.C.; Camacho-Martinez, F.

    1985-09-01

    The bilobed flap is a simple reconstructive technique principally used to correct substantial defects in the facial region. The authors present their experience with this local flap in the difficult plantar area, with excellent short-term functional results. They describe the special characteristics of the bilobed flap in this zone, and comment on its indications and possible complications.

  1. Blown flap noise prediction

    NASA Technical Reports Server (NTRS)

    Reddy, N. N.

    1978-01-01

    Theoretical and experimental developments of flow-surface interaction noise with a particular emphasis on blown-flap noise were reviewed. Several blown-flap noise prediction methods were evaluated by comparing predicted acoustic levels, directivity, and spectra with a recently obtained data base. A prediction method was selected and a detailed step-by-step description of this method was provided to develop a computer module to calculate one-third octave band frequency spectra at any given location in the far-field for under-the-wing and upper surface blown configurations as a function of geometric and operational parameters.

  2. Externally blown flap impingement noise.

    NASA Technical Reports Server (NTRS)

    Putnam, T. W.; Lasagna, P. L.

    1972-01-01

    An investigation of externally blown flap impingement noise was conducted using a full-scale turbofan engine and aircraft wing. The noise produced with a daisy nozzle installed on the engine exhaust system was greater than that produced by a conical nozzle at the same thrust. The daisy nozzle caused the jet velocity to decay about 35 percent at the flap. The presence of the wing next to the conical nozzle increased the noise, as did increasing the flap deflection. Compared with the conical nozzle, the daisy nozzle produced slightly less noise at a flap deflection of 60 deg but produced more noise at the lower flap deflections tested.

  3. 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.

  4. Local Flaps of The Hand

    PubMed Central

    Rehim, Shady A.; Chung, Kevin C.

    2014-01-01

    Synopsis A local flap consists of skin and subcutaneous tissue that is harvested from a site nearby a given defect while maintaining its intrinsic blood supply. When a soft tissue defect of the hand is not amenable to primary closure or skin grafting, local skin flaps can be a used as a reliable source of soft tissue replacement that replaces like with like. Flaps are categorized based on their composition, method of transfer, flap design and blood supply, yet flap circulation is considered the most critical factor for the flap survival. This article reviews the classification of local skin flaps of the hand and offers a practical reconstructive approach for several soft tissue defects of the hand and digits. PMID:24731606

  5. The Deltopectoral Flap Revisited: The Internal Mammary Artery Perforator Flap.

    PubMed

    Ibrahim, Amir; Atiyeh, Bishara; Karami, Reem; Adelman, David M; Papazian, Nazareth J

    2016-03-01

    Pharyngo-esophageal and tracheostomal defects pose a challenge in head and neck reconstruction whenever microanastomosis is extremely difficult in hostile neck that is previously dissected and irradiated. The deltopectoral (DP) flap was initially described as a pedicled flap for such reconstruction with acceptable postoperative results. A major drawback is still that the DP flap is based on 3 perforator vessels leading to a decreased arc of rotation. The DP flap also left contour deformities in the donor site. The internal mammary artery perforator flap was described as a refinement of the deltopectoral flap. It is a pedicled fasciocutaneous flap based on a single perforator, with comparable and reliable blood supply compared with the DP flap, giving it the benefit of having a wide arc of rotation. It is both thin and pliable, with good skin color match and texture. The donor site can be closed primarily with no esthetic deformity and minimal morbidity. The procedure is relatively simple and does not require microvascular expertise. In this report, the authors describe a patient in whom bilateral internal mammary artery perforator flaps were used for subtotal pharyngo-esophageal reconstruction and neck resurfacing. The flaps healed uneventfully bilaterally with no postoperative complications.

  6. Microdissected Prefabricated Flap: An Evolution in Flap Prefabrication

    PubMed Central

    2016-01-01

    When traditional flap techniques are not feasible, we apply flap prefabrication, which is more complicated and sophisticated but supplies large and thin flaps. There are some disadvantages to the technique that require improvement, such as venous congestion after flap transfer, which requires months for neoangiogenesis and necessitates a vascular carrier. Here, the author presents a new technique, called as ‘microdissected prefabricated flap,’ to successfully produce a safe, large, and thin flap. This technique is based on the microdissection of the perforators to the greatest extent possible, spreading them out into the subdermal level and using them as a carrier. The details and the application of this technique are presented and reported. PMID:27896196

  7. Novel flaps for head and neck reconstruction.

    PubMed

    Ahmad, Quazi Ghazwan; Shankhdhar, Vinay Kant

    2010-04-01

    The head and neck region is important both functionally and aesthetically and its reconstruction poses a formidable challenge for plastic surgeons. A perforator flap is a flap of skin or subcutaneous tissue supplied by a vessel that perforates the deep fascia to gain access to flap. With improvement in our knowledge of the anatomy of blood supply to the skin, the perforator flaps have opened a whole new horizon for the plastic surgeon to choose flaps with better function and cosmesis. The locally available perforators enable flaps to be designed with excellent match in tissue characteristics. Perforator flaps limit donor site morbidity and as they are islanded complete insetting is possible in a single stage. The principal perforator flaps such as facial artery perforator flap, platysma flap and its variant the submental flap and supra-clavicular artery flap used in the head and neck reconstruction are discussed. The more commonly used flaps are the free radial artery forearm flap and the anterolateral thigh flap while the novel ones are the thoracodorsal artery perforator flap, medial sural artery perforator flap and the toe-web flap for commissure reconstruction. The indications, reach and drawbacks of these flaps have been discussed in this review.

  8. Superficial ulnar artery perforator flap.

    PubMed

    Schonauer, Fabrizio; Marlino, Sergio; Turrà, Francesco; Graziano, Pasquale; Dell'Aversana Orabona, Giovanni

    2014-09-01

    Superficial ulnar artery is a rare finding but shows significant surgical implications. Its thinness and pliability make this flap an excellent solution for soft tissue reconstruction, especially in the head and neck region. We hereby report a successful free superficial ulnar artery perforator forearm flap transfer for tongue reconstruction. A 64-year-old man presenting with a squamous cell carcinoma of the left tongue underwent a wide resection of the tumor, left radical neck dissection, and reconstruction of the tongue and the left tonsillar pillar with the mentioned flap. No complications were observed postoperatively. The flap survived completely; no recurrence at 6 months of follow-up was detected. Superficial ulnar artery perforator flap has shown to be a safe alternative to other free tissue flaps in specific forearm anatomic conditions.

  9. The Versatile Modiolus Perforator Flap

    PubMed Central

    Gunnarsson, Gudjon Leifur; Thomsen, Jorn Bo

    2016-01-01

    Background: Perforator flaps are well established, and their usefulness as freestyle island flaps is recognized. The whereabouts of vascular perforators and classification of perforator flaps in the face are a debated subject, despite several anatomical studies showing similar consistency. In our experience using freestyle facial perforator flaps, we have located areas where perforators are consistently found. This study is focused on a particular perforator lateral to the angle of the mouth; the modiolus and the versatile modiolus perforator flap. Methods: A cohort case series of 14 modiolus perforator flap reconstructions in 14 patients and a color Doppler ultrasonography localization of the modiolus perforator in 10 volunteers. Results: All 14 flaps were successfully used to reconstruct the defects involved, and the location of the perforator was at the level of the modiolus as predicted. The color Doppler ultrasonography study detected a sizeable perforator at the level of the modiolus lateral to the angle of the mouth within a radius of 1 cm. This confirms the anatomical findings of previous authors and indicates that the modiolus perforator is a consistent anatomical finding, and flaps based on it can be recommended for several indications from the reconstruction of defects in the perioral area, cheek and nose. Conclusions: The modiolus is a well-described anatomical area containing a sizeable perforator that is consistently present and readily visualized using color Doppler ultrasonography. We have used the modiolus perforator flap successfully for several indications, and it is our first choice for perioral reconstruction. PMID:27257591

  10. Skin flaps in reconstructive surgery.

    PubMed

    Pavletic, M M

    1990-01-01

    A skin flap (pedicle graft) is a partially detached segment of skin and subcutaneous tissue that includes a blood supply essential to its survival. As a result, skin flaps are capable of closing a variety of defects, including poorly vascularized wound beds that are incapable of maintaining free grafts. In many cases, skin flaps can bypass economically many of the potential problems associated with healing by second intention. This article presents an overview of pedicle grafts, with emphasis on the clinical use of local flap techniques.

  11. Intracranial microvascular free flaps.

    PubMed

    Levine, Steven; Garfein, Evan S; Weiner, Howard; Yaremchuk, Michael J; Saadeh, Pierre B; Gurtner, Geoffrey; Levine, Jamie P; Warren, Stephen M

    2009-02-01

    Large acquired intracranial defects can result from trauma or surgery. When reoperation is required because of infection or tumor recurrence, management of the intracranial dead space can be challenging. By providing well-vascularized bulky tissue, intracranial microvascular free flaps offer potential solutions to these life-threatening complications. A multi-institutional retrospective chart and radiographic review was performed of all patients who underwent microvascular free-flap surgery for salvage treatment of postoperative intracranial infections between 1998 and 2006. A total of six patients were identified with large intracranial defects and postoperative intracranial infections. Four patients had parenchymal resections for tumor or seizure and two patients had posttraumatic encephalomalacia. All patients underwent operative debridement and intracranial free-flap reconstruction using the latissimus dorsi muscle (N=2), rectus abdominis muscle (N=2), or omentum (N=2). All patients had titanium (N=4) or Medpor (N=2) cranioplasties. We concluded that surgery or trauma can result in significant intracranial dead space. Treatment of postoperative intracranial infection can be challenging. Vascularized free tissue transfer not only fills the void, but also provides a delivery system for immune cells, antibodies, and systemically administered antibiotics. The early use of this technique when intracranial dead space and infection coexist is beneficial.

  12. Reduction of Flap Side Edge Noise - the Blowing Flap

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, THomas F.

    2005-01-01

    A technique to reduce the noise radiating from a wing-flap side edge is being developed. As an airplane wing with an extended flap is exposed to a subsonic airflow, air is blown outward through thin rectangular chord-wise slots at various locations along the side edges and side surface of the flap to weaken and push away the vortices that originate in that region of the flap and are responsible for important noise emissions. Air is blown through the slots at up to twice the local flow velocity. The blowing is done using one or multiple slots, where a slot is located along the top, bottom or side surface of the flap along the side edge, or also along the intersection of the bottom (or top) and side surfaces.

  13. Enamel matrix proteins (Emdogain) in combination with coronally advanced flap or subepithelial connective tissue graft in the treatment of shallow gingival recessions.

    PubMed

    Berlucchi, Ignazio; Francetti, Luca; Del Fabbro, Massimo; Testori, Tiziano; Weinstein, Roberto L

    2002-12-01

    This article describes two different surgical techniques of root coverage using Emdogain and shows preliminary results on 26 shallow recessions in 14 patients. For the treatment of 13 recessions, Emdogain was used in combination with a coronally advanced flap (CAF+EMD group). In the other 13 recessions, Emdogain and the flap were used in combination with a subepithelial connective tissue graft (CAF+CTG+EMD group). For the CAF+EMD group, the root coverage at 6 months was 93.97%, with an attachment gain of 3.2 mm; for the CAF+CTG+EMD group, the root coverage was 93.59%, with an attachment gain of 3.4 mm (no statistically significant difference between groups). When complete root coverage was not achieved, the residual recession was 1 mm in four cases and 2 mm in one case. Keratinized gingiva was increased for both groups, but more for the CAF+CTG+EMD group (1.38 mm versus 0.69 mm; statistically significant difference). Clinical attachment level decreased significantly in both groups, from 4.46 to 1.23 mm in the CAF+EMD group, and from 4.62 to 1.23 mm in the CAF+CTG+EMD group. Preliminary results show that Emdogain, in combination with CAF or CAF+CTG for the treatment of Miller Class I or II gingival recessions, displays good clinical results, with percentage of root coverage comparable or superior to other techniques. Further experimental studies on the dynamics of wound healing are needed to prove that EMD is really responsible for improving the percentage of regenerated versus repaired tissues with respect to other techniques.

  14. Effects of calcitriol on random skin flap survival in rats

    PubMed Central

    Zhou, Kai-liang; Zhang, Yi-hui; Lin, Ding-sheng; Tao, Xian-yao; Xu, Hua-zi

    2016-01-01

    Calcitriol, a metabolite of vitamin D, is often used in osteoporosis clinics. However, the material has other bioactivities; for example, it accelerates angiogenesis, has anti-inflammatory properties, and inhibits oxidative stress. We investigated the effects of calcitriol in a random skin flap rat model. “McFarlane flap” models were established in 84 male Sprague Dawley rats, divided into two groups. One group received intraperitoneal injections of calcitriol (2 μg/kg/day) whereas control rats received intraperitoneal injections of saline. The percentage flap survival area and tissue water content were measured 7 days later, which showed that calcitriol improved flap survival area and reduced tissue edema. It also increased the mean vessel density and upregulated levels of VEGF mRNA/protein, both of which promote flap angiogenesis. Moreover, it decreased leukocyte and macrophage infiltration, reduced the inflammatory proteins IL1β and IL6, increased SOD activity, decreased MDA content, and upregulated the level of autophagy. Overall, our results suggest that calcitriol promotes skin flap survival by accelerating angiogenesis, having anti-inflammatory effects, reducing oxidative stress, and promoting autophagy. PMID:26732750

  15. Flap Edge Noise Reduction Fins

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R. (Inventor); Choudhan, Meelan M. (Inventor)

    2015-01-01

    A flap of the type that is movably connected to an aircraft wing to provide control of an aircraft in flight includes opposite ends, wherein at least a first opposite end includes a plurality of substantially rigid, laterally extending protrusions that are spaced apart to form a plurality of fluidly interconnected passageways. The passageways have openings adjacent to upper and lower sides of the flap, and the passageways include a plurality of bends such that high pressure fluid flows from a high pressure region to a low pressure region to provide a boundary condition that inhibits noise resulting from airflow around the end of the flap.

  16. Dancing girl flap: a new flap suitable for web release.

    PubMed

    Shinya, K

    1999-12-01

    To create a deep web, a flap must be designed to have a high elongation effect in one direction along the mid-lateral line of the finger and also to have a shortening effect in the other direction, crossing at a right angle to the mid-lateral line. The dancing girl flap is a modification of a four-flap Z-plasty with two additional Z-plasties. It has a high elongation effect in one direction (>550%) and a shortening effect in the other direction at a right angle (<33%), creating a deep, U-shaped surface. This new flap can be used to release severe scar contracture with a web, and is most suitable for incomplete syndactyly with webs as high as the proximal interphalangeal joint.

  17. Flap monitoring using infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Keller, Alex; Wright, Leigh P.; Elmandjra, Mohamed; Mao, Jian-min

    2006-02-01

    We report results of clinical trials on flap monitoring in 65 plastic surgeries. Hemoglobin oxygen saturation of flap tissue (StO II) was monitored non-invasively by using ODISsey TM tissue oximeter, an infrared spectroscopic device. StO II measurements were conducted both intra-operatively and post-operatively. From the intra-operative measurements, we observed that StO II values dropped when the main blood vessels supplying the flap were clamped in surgery, and that StO II jumped after anastomosis to a value close to its pre-operative value. From post-operative monitoring measurements for the 65 flap cases, each lasted two days or so, we found that the StO II values approach to a level close to the baseline if the surgery was successful, and that the StO II value dropped to a value below 30% if there is a perfusion compromise, such as vascular thrombosis.

  18. Full scale upper surface blown flap noise

    NASA Technical Reports Server (NTRS)

    Heidelberg, L. J.; Homyak, L.; Jones, W. L.

    1975-01-01

    A highly noise suppressed TF 34 engine was used to investigate the noise of several powered lift configurations involving upper surface blown (USB) flaps. The configuration variables were nozzle type (i.e. slot and circular with deflector), flap chord length, and flap angle. The results of velocity surveys at both the nozzle exit and the flap trailing edge are also presented and used for correlation of the noise data. Configurations using a long flap design were 4 db quieter than a short flap typical of current trends in USB flap design. The lower noise for the long flap is attributed primarily to the greater velocity decay of the jet at the flap trailing edge. The full-scale data revealed substantially more quadrupole noise in the region near the deflected jet than observed in previous sub-scale tests.

  19. Evidence that the DNA mismatch repair system removes 1-nucleotide Okazaki fragment flaps.

    PubMed

    Kadyrova, Lyudmila Y; Dahal, Basanta K; Kadyrov, Farid A

    2015-10-02

    The DNA mismatch repair (MMR) system plays a major role in promoting genome stability and suppressing carcinogenesis. In this work, we investigated whether the MMR system is involved in Okazaki fragment maturation. We found that in the yeast Saccharomyces cerevisiae, the MMR system and the flap endonuclease Rad27 act in overlapping pathways that protect the nuclear genome from 1-bp insertions. In addition, we determined that purified yeast and human MutSα proteins recognize 1-nucleotide DNA and RNA flaps. In reconstituted human systems, MutSα, proliferating cell nuclear antigen, and replication factor C activate MutLα endonuclease to remove the flaps. ATPase and endonuclease mutants of MutLα are defective in the flap removal. These results suggest that the MMR system contributes to the removal of 1-nucleotide Okazaki fragment flaps.

  20. The Role of Muscle Flaps for Salvage of Failed Perforator Free Flaps

    PubMed Central

    2015-01-01

    Background: Despite the most heroic efforts, sometimes free flaps fail. Perforator free flaps are not invincible and can suffer the same fate. The real challenge is how to decide what is the next best choice for achieving the desired outcome. Methods: Over the past decade, 298 free perforator flaps were used in our institution. Total failure occurred in 16 patients, and partial failure requiring a second free flap occurred in an additional 6 patients for a true success rate of 93%. All failures had some form of secondary vascularized tissue transfer, which included the use of muscle flaps in 9 (41%) different patients. Results: Initial flap salvage after a failed perforator free flap was attempted with 12 perforator and 5 muscle free flaps as well as 1 perforator and 2 muscle local flaps. These were not all successful, with loss of 3 muscle free flaps and 3 perforator flaps. Tertiary free flap coverage was successful in 3 cases using 2 muscle flaps and 1 perforator free flap. Local fasciocutaneous flaps or primary wound closure was used in the remaining individuals. Conclusions: Microsurgical tissue transfers can be the most rewarding and at the same time the most challenging reconstructive endeavor. Persistence in achieving the desired outcome can require multiple steps. Perforator flaps are an important asset to obtain this goal. However, muscle flaps can still be a useful alternative, and the message is that they should not be overlooked as sometimes a viable option. PMID:26893989

  1. The rat saphenous flap: a fasciocutaneous free flap model without panniculus carnosus.

    PubMed

    Mutaf, M; Tasaki, Y; Tanaka, K; Fujii, T

    1995-10-01

    The rat saphenous flap is described as a new experimental model for free flap studies. This is a fasciocutaneous free flap based on the saphenofemoral vascular pedicle. The flap may include the entire medial aspect of the lower leg between the knee and ankle. Thirty flaps were harvested from 15 inbred rats. Each flap was transferred to the anterior neck of a recipient rat of the same inbred strain so that 15 flaps were vascularized free flaps using the standard end-to-end microvascular technique and the other 15 flaps were nonvascularized free grafts. All but two (technical failure) of the vascularized flaps showed complete survival, whereas all nonvascularized flaps completely necrosed 2 weeks after transfer. It was concluded that the rat saphenous flap has several advantages such as a long and consistent vascular pedicle, ease of harvest, and an all-or-none survival pattern. Furthermore, as a unique feature of this flap, histological analysis revealed that the rat saphenous flap is composed of the skin and underlying fascia without panniculus carnosus. We therefore suggest that the rat saphenous flap is the first true fasciocutaneous free flap model in the rat. In this paper, in addition to illustrating the anatomy of the saphenous vessels and describing a new fasciocutaneous free flap model based on these vessels, we have documented some anatomical details of the rat leg that have never been described in the literature related to the rat anatomy.

  2. Buried free flaps in head and neck reconstruction: higher risk of free flap failure?

    PubMed

    Reiter, M; Harréus, U; Kisser, U; Betz, C S; Baumeister, Ph

    2017-01-01

    Thrombosis of the pedicle is central to free flap failure, and early revision of a compromised flap is the key to successfully salvage a flap. Therefore, the majority of free flaps in reconstructive head and neck surgery are used with the ability to visually examine the flap. Sometimes, due to intra-operative circumstances, it is necessary to use a flap that cannot be monitored externally. These flaps are called buried flaps and have the reputation of being put at risk. The current literature provides only limited data to support or disprove this position. A single institution retrospective review of patient charts between 2007 and 2015 was performed. Flap monitoring was carried out with hand-held Doppler of the pedicle hourly for the first 72 h in all cases. Additional duplex ultrasound was performed in the majority of buried flaps. A total of 437 flaps were included into the study. 37 flaps (7.8 %) were identified to fulfill the criteria of a buried free flap. In total, four patients had complications, three of which required operative reexploration. All interventions were successful, resulting in no flap loss in our series. An accurate operation technique combined with meticulous monitoring protocols supported by duplex ultrasound can result in satisfactory outcome of buried flaps. No enhanced risk of flap loss of buried flaps was found in our cohort.

  3. [Significance of abdominal wall CT-angiography in planning DIEA perforator flaps, TRAM flaps and SIEA flaps].

    PubMed

    Fansa, H; Schirmer, S; Frerichs, O; Gehl, H B

    2011-04-01

    Muscle sparing TRAM flaps and DIEA perforator flaps are standard procedures for breast reconstruction. Recently CT-angiography has been established to evaluate perforator vessels pre-operatively. CT-angiography was introduced to our department in July 2009. In a retrospective analysis data of the last 20 patients (altogether 22 flaps) before CT-angiography introduction and the following 20 (also 22 flaps) patients after introduction of CT-angiography were analysed with regard to the ratio of TRAM to DIEP flaps, and the time required to raise the flaps. The same surgeon raised all flaps. As different surgeons performed dissection of the recipient site, anastomoses, and insertion of flaps, and patients received primary (with sentinel or complete lymphadenctomy) or secondary reconstructions, only the time required harvesting the flap was compared. Thus other influences on raising the flap were eliminated. DIEP flaps were harvested with one single perforator. If perfusion or was considered not to be safe via one single perforator a muscle sparing TRAM flap (ms2) was raised. Angiography was performed using a 64-slice multi-detector CT scanner. CT-angiography did not lead to an increased rate of DIEP flaps in relation to ms2-TRAM flaps. Harvesting time of all flap types with CT-angiography on average was 121 min, without CT-angiography 135 min. This was not significantly different. However, separate analysis of DIEP flaps and ms2-TRAM flaps revealed a significant advantage of CT-angiography based harvesting of DIEP flaps of 26 min: with CT-angiography 101 min vs. 127 min without CT-angiography (p<0.028). There were no significant differences for ms2-TRAM flaps. All scans showed course and branching, diameter and size of the inferior epigastric artery. If evident the superficial inferior epigastric artery (SIEA) was marked. Dosage was 292 mGy-606 mGy×cm dependent on body weight. CTDI was 6.8-14.7 mGy. CT-angiography is a reproducible and observer independent procedure

  4. Experience in Reconstruction for Small Digital Defects With Free Flaps.

    PubMed

    Hung, Min-Hsiang; Huang, Kuo-Feng; Chiu, Haw-Yen; Chao, Wai-Nang

    2016-03-01

    Traumatic injuries to the digits resulting in soft tissue or bone loss require reconstruction. Traditionally, local flaps, such as homodigital flaps, heterodigital flaps, pedicled flaps, or distant flaps, are used for digital resurfacing. However, free tissue transfers can be used in selected patients. In this study, we present the use of different free flaps including groin skin flaps, groin osteocutaneous flaps, groin chimeric flaps, second dorsal metacarpal artery flaps, and partial toe flaps for digital reconstruction. A total of 19 digits were treated with 16 free flaps in our hospital. Of the flaps used, 5 were free groin skin flaps, 4 were free partial toe flaps, 3 were free groin chimeric flaps, 2 were free groin osteocutaneous flaps, and 2 were free second dorsal metacarpal artery flaps. The average flap size was 4.7 × 2.0 cm (range, 1.5 × 1 to 5 × 4 cm), and the average operative time was 6.0 hours (range, 4-9 hours). All flaps survived without partial or total necrosis. In conclusion, the free flap is a reliable and safe alternative for digital reconstruction. Moreover, the free groin flap provides not only a chimeric pattern for multiple fingers coverage but also an osteocutaneous pattern for thumb lengthening. The free second dorsal metacarpal artery flap provides a tenocutaneous pattern for tendon reconstruction and soft tissue coverage simultaneously, and the free partial toe flap is an excellent alternative for pulp reconstruction in terms of aesthetic appearance and functional outcome.

  5. 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.

  6. Free digital artery flap: an ideal flap for large finger defects in situations where local flaps are precluded.

    PubMed

    Wong, Chin-Ho; Teoh, Lam-Chuan; Lee, Jonathan Y-L; Yam, Andrew K-T; Khoo, David B-A; Yong, Fok-Chuan

    2008-03-01

    The heterodigital arterialized flap is increasingly accepted as a flap of choice for reconstruction of large finger wounds. However, in situations where the adjacent fingers sustained concomitant injuries, the use of this flap as a local flap is precluded. This paper describes our experience with the free digital artery flap as an evolution of the heterodigital arterialized flap. Four patients with large finger wounds were reconstructed with free digital artery flap. Our indications for digital artery free flap were concomitant injuries to adjacent fingers that precluded their use as donor sites. The arterial supply of the flap was from the digital artery and the venous drainage was from the dominant dorsal vein of the finger. The flap was harvested from the ulnar side of the finger. The digital nerve was left in situ to minimize donor morbidity. The donor site was covered with a full-thickness skin graft and secured with bolster dressings. Early intensive mobilization was implemented for all patients. All flaps survived. No venous congestion was noted and primary healing was achieved in all flaps. In addition to providing well-vascularized tissue for coverage of vital structures, the digital artery was also used as a flow-through flap for finger revascularization in one patient. Donor-site morbidity was minimal, with all fingers retaining protective pulp sensation and the distal and proximal interphalangeal joints retaining full ranges of motion. In conclusion, the free digital artery flap is a versatile flap that is ideal for coverage of large-sized finger defects in situations where local flaps are unavailable. Donor-site morbidity can be minimized by preservation of the digital nerve, firmly securing the skin graft with bolster dressings, and early mobilization of the donor finger.

  7. 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.

  8. Traumatic Forefoot Reconstructions With Free Perforator Flaps.

    PubMed

    Zhu, Yue-Liang; He, Xiao-Qing; Wang, Yi; Lv, Qian; Fan, Xin-Yv; Xu, Yong-Qing

    2015-01-01

    The forefoot is critical to normal walking; thus, any reconstruction of forefoot defects, including the soft tissues, must be carefully done. The free perforator flap, with its physiologic circulation, lower donor site morbidity, and minimal thickness is the most popular technique in plastic and microsurgery, and is theoretically the most suitable for such forefoot reconstruction. However, these flaps are generally recognized as more difficult and time-consuming to create than other flaps. In 41 patients with traumatic forefoot defects, we reconstructed the forefoot integument using 5 types of free perforator flaps. The overall functional and cosmetic outcomes were excellent. Three flaps required repeat exploration; one survived. The most common complications were insufficient perfusion and the need for second debulking. The key to our success was thoroughly debriding devitalized bone and soft tissue before attaching the flap. Forefoot reconstruction with a free perforator flap provides better function, better cosmesis, better weightbearing, and better gait than the other flaps we have used.

  9. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps. Wing flaps, their operating mechanisms, and their supporting structures must be designed for critical...

  10. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps. Wing flaps, their operating mechanisms, and their supporting structures must be designed for critical...

  11. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps. Wing flaps, their operating mechanisms, and their supporting structures must be designed for critical...

  12. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps. Wing flaps, their operating mechanisms, and their supporting structures must be designed for critical...

  13. 14 CFR 25.457 - Wing flaps.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: TRANSPORT CATEGORY AIRPLANES Structure Control Surface and System Loads § 25.457 Wing flaps. Wing flaps, their operating mechanisms, and their supporting structures must be designed for critical...

  14. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Flap interconnection. 23.701 Section 23.701 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION AIRCRAFT AIRWORTHINESS... Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a...

  15. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a system... independent of the flap drive system; or by an approved equivalent means; or (2) Be designed so that...

  16. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a system... independent of the flap drive system; or by an approved equivalent means; or (2) Be designed so that...

  17. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a system... independent of the flap drive system; or by an approved equivalent means; or (2) Be designed so that...

  18. 14 CFR 23.701 - Flap interconnection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... STANDARDS: NORMAL, UTILITY, ACROBATIC, AND COMMUTER CATEGORY AIRPLANES Design and Construction Control Systems § 23.701 Flap interconnection. (a) The main wing flaps and related movable surfaces as a system... independent of the flap drive system; or by an approved equivalent means; or (2) Be designed so that...

  19. The Sternohyoid Flap for Facial Reanimation.

    PubMed

    Alam, Daniel S

    2016-02-01

    This article discusses the use of the sternohyoid muscle for facial reanimation. The report outlines the rationale for use, the technical aspects of flap harvest, and early clinical outcomes. The utility of the flap and its comparative attributes relative to the gracilis flap are discussed.

  20. Microvascular free flaps in head and neck surgery: complications and outcome of 1000 flaps.

    PubMed

    Pohlenz, P; Klatt, J; Schön, G; Blessmann, M; Li, L; Schmelzle, R

    2012-06-01

    This study analyzed the surgical outcome and complications of 1000 microvascular free flaps performed at the authors' institution in Germany, between 1987 and 2010. 972 patients underwent reconstruction with 1000 flaps: 28% latissimus dorsi flaps, 27% radial forearm flaps, 20% iliac crest flaps, 12% fibula flaps, 6% jejunal flaps, 2% anterolateral thigh flaps, and 5% other flaps. 130 failures (7.6%) were encountered, including 58 complete flap failures (44.6%) and 72 partial free-flap failures (55.4%). This study confirms that free flaps are extremely reliable in achieving successful reconstruction of the head and neck, but it is essential that complications be recognized and addressed early in their course to prevent or minimize devastating consequences. Owing to the large number of possible errors in flap transplantation, microsurgeons should always check everything for themselves. The on-duty doctors and nursing staff should not be trusted blindly. Venous thrombosis and cervical haematoma are the most common complications at the recipient site and are mainly responsible for flap failure, while complications occurring at the donor site may result from dehiscence and graft necrosis. When a compromised flap is identified, surgical re-exploration should not be deferred.

  1. Schooling of flapping wings: Simulations

    NASA Astrophysics Data System (ADS)

    Masoud, Hassan; Becker, Alexander; Ristroph, Leif; Shelley, Michael

    2014-11-01

    We examine the locomotion of an infinite array of wings that heave vertically with a prescribed sinusoidal motion and are free to translate in the horizontal direction. To do this, we simulate the motion of a freely translating flapping airfoil in a domain with periodic horizontal boundary conditions. These simulations indicate that the wings can ``take advantage'' of their collectively generated wake flows. In agreement with our experiments in a rotational geometry, we find ranges of flapping frequency over which there are multiple stable states of locomotion, with one of these swimming states having both higher speeds and efficiencies than an isolated flapping and locomoting wing. A simple mathematical model, which emphasizes the importance of history dependence in vortical flows, explains this multi-stability. These results may be important to understanding the role of hydrodynamic interactions in fish schooling and bird flocking.

  2. Efficient flapping flight of pterosaurs

    NASA Astrophysics Data System (ADS)

    Strang, Karl Axel

    In the late eighteenth century, humans discovered the first pterosaur fossil remains and have been fascinated by their existence ever since. Pterosaurs exploited their membrane wings in a sophisticated manner for flight control and propulsion, and were likely the most efficient and effective flyers ever to inhabit our planet. The flapping gait is a complex combination of motions that sustains and propels an animal in the air. Because pterosaurs were so large with wingspans up to eleven meters, if they could have sustained flapping flight, they would have had to achieve high propulsive efficiencies. Identifying the wing motions that contribute the most to propulsive efficiency is key to understanding pterosaur flight, and therefore to shedding light on flapping flight in general and the design of efficient ornithopters. This study is based on published results for a very well-preserved specimen of Coloborhynchus robustus, for which the joints are well-known and thoroughly described in the literature. Simplifying assumptions are made to estimate the characteristics that can not be inferred directly from the fossil remains. For a given animal, maximizing efficiency is equivalent to minimizing power at a given thrust and speed. We therefore aim at finding the flapping gait, that is the joint motions, that minimize the required flapping power. The power is computed from the aerodynamic forces created during a given wing motion. We develop an unsteady three-dimensional code based on the vortex-lattice method, which correlates well with published results for unsteady motions of rectangular wings. In the aerodynamic model, the rigid pterosaur wing is defined by the position of the bones. In the aeroelastic model, we add the flexibility of the bones and of the wing membrane. The nonlinear structural behavior of the membrane is reduced to a linear modal decomposition, assuming small deflections about the reference wing geometry. The reference wing geometry is computed for

  3. Etanercept protects myocutaneous flaps from ischaemia reperfusion injury: An experimental study in a rat tram flap model.

    PubMed

    Ersoy, Burak; Çevik, Özge; Çilingir, Özlem Tuğçe

    2016-08-01

    Background Being an inevitable component of free tissue transfer, ischemia-reperfusion injury tends to contribute to flap failure. TNF-α is an important proinflammatory cytokine and a prominent mediator of the ischemia-reperfusion injury. Etanercept, a soluble TNF-α binding protein, has shown anti-inflammatory and anti-apoptotic effects in animal models of renal and myocardial ischemia-reperfusion injury. We have designed an experimental study to investigate the effect of etanercept on myocutaneous ischemia-reperfusion injury on transverse rectus abdominis myocutaneous flap model in rats. Methods Twenty-four male Sprague-Dawley rats were divided into 3 groups: In group 1 (sham), the TRAM flap was raised and sutured back without further intervention. In group 2 (control), the flap was raised and the ischemia-reperfusion protocol was followed. In group 3, etanercept (10 mg/kg, i.v.) was administered 10 minutes before reperfusion. At the end of the reperfusion period, biochemical and histolopathological evaluations were performed on serum and tissue samples. Results In the etanercept group the IMA and 8-OHdG levels (p = 0.005 and p = 0.004, respectively) were found significantly lower, and the GSH and SOD levels (p = 0.01 and p < 0.001, respectively) significantly higher in comparison to the control group. The histopathological analysis has revealed a lower degree of hyalinization, degenerated muscle fibers and nuclear change in the etanercept group compared to the control group. Conclusion The results of our experimental study indicate that etanercept offers protection against ischemia-reperfusion injury in skeletal muscle tissue, enhancing the TRAM flap viability. The ability of etanercept to induce ischemic tolerance suggests that it may be applicable in free-flap surgery.

  4. BCL-2 and Bax Expression in Skin Flaps Treated with Finasteride or Azelaic Acid

    PubMed Central

    Ayatollahi, Seyyed Abdulmajid; Ajami, Marjan; Reyhanfard, Hamed; Asadi, Yasin; Nassiri-Kashani, Mansour; Rashighi Firoozabadi, Mehdi; Davoodi, Sayed Hossein; Habibi, Esmaeil; Pazoki-Toroudi, Hamidreza

    2012-01-01

    Despite all modern surgical techniques, skin flap that is considered as the main method in most reconstructive surgeries puts the skin tissue at danger of necrosis and apoptosis derived from ischemia. Therefore, finding a treatment for decreasing the apoptosis derived from flap ischemia will be useful in clinic. In present study, we evaluated the effect of azelaic acid 20% and finasteride on expression of BCL-2 and bax proteins after the skin flap surgery. For this purpose, 21 rats were entered in three groups including control, azelaic acid 20% and finasteride, all experienced skin flap surgery and then flap tissue was assessed for determining the expression of proteins in 5 slices prepared from each rat that were graded between – to +++ scales. Both azelaic acid and finasteride increased the expression of BCL-2 protein (p < 0.05) and decrease the expression of bax protein (p < 0.05). These results suggested an antiapoptotic role for finasteride and azelaic acid in preserving the flap after the ischemia reperfusion insult. PMID:24250563

  5. Vertical trapezius musculocutaneous flap: a retrospective study.

    PubMed

    Papadopoulos, Othon N; Chrisostomidis, Chrisostomos I; Georgiou, Panagis N; Frangoulis, Marios B; Zapantis-Fragos, Menelaos K; Champsas, Grigorios G

    2005-01-01

    From 1986 to 2001, 17 patients (aged 26-77 years) were treated using the vertical trapezius musculocutaneous flap. A two-stage procedure was used in 7 and a single-stage island flap in 10. The donor site was closed directly in all patients. Mean length of hospital stay was 16 days (range 12-25). There was no operative mortality. Complications were one partial flap necrosis and two seromas of the donor site, complicated by infection. With a minimum follow-up of more than two years, our study confirms the usefulness of the vertical trapezius musculocutaneous flap in head and neck reconstructive surgery. It is a reliable, thin flap of uniform thickness, which carries hairless skin. The length and thickness of its pedicle allows excellent mobility. The main disadvantage of the flap is the complete sacrifice of the muscle necessary for total mobilisation of the flap, and the intraoperative repositioning of the patient.

  6. Scrotal reconstruction with modified pudendal thigh flaps.

    PubMed

    Mopuri, Nabil; O'Connor, Edmund Fitzgerald; Iwuagwu, Fortune C

    2016-02-01

    Scrotal skin loss can occur following trauma, Fournier's gangrene, post tumour excision, burns, etc. There are many techniques described in the literature including residual scrotal skin mobilization, skin grafts, pedicled and free flaps. The management is complex and challenging shown by the multiplicity of flaps and techniques described in the literature. We used a modified pudendal thigh flap to reconstruct scrotal defects in five patients. This study describes the vascularity of the flap, technique of elevation and the inset of the flap. The elevation and particularly the insetting make it different from other flaps raised on this vascular network for scrotal reconstruction. This pedicled flap is robust, reliable, resilient and produces a neo-scrotum that looks natural in appearance, offers good-quality skin cover and cushion to the testes as well as protective sensation.

  7. Topical application of nitrosonifedipine, a novel radical scavenger, ameliorates ischemic skin flap necrosis in a mouse model.

    PubMed

    Fukunaga, Yutaka; Izawa-Ishizawa, Yuki; Horinouchi, Yuya; Sairyo, Eriko; Ikeda, Yasumasa; Ishizawa, Keisuke; Tsuchiya, Koichiro; Abe, Yoshiro; Hashimoto, Ichiro; Tamaki, Toshiaki

    2017-01-16

    Ischemic skin flap necrosis can occur in random pattern flaps. An excess amount of reactive oxygen species is generated and causes necrosis in the ischemic tissue. Nitrosonifedipine (NO-NIF) has been demonstrated to possess potent radical scavenging ability. However, there has been no study on the effects of NO-NIF on ischemic skin flap necrosis. Therefore, they evaluated the potential of NO-NIF in ameliorating ischemic skin flap necrosis in a mouse model. A random pattern skin flap (1.0 × 3.0 cm) was elevated on the dorsum of C57BL/6 mice. NO-NIF was administered by topical injection immediately after surgery and every 24 hours thereafter. Flap survival was evaluated on postoperative day 7. Tissue samples from the skin flaps were harvested on postoperative days 1 and 3 to analyze oxidative stress, apoptosis and endothelial dysfunction. The viable area of the flap in the NO-NIF group was significantly increased (78.30 ± 7.041%) compared with that of the control group (47.77 ± 6.549%, p < 0.01). NO-NIF reduced oxidative stress, apoptosis and endothelial dysfunction, which were evidenced by the decrease of malondialdehyde, p22phox protein expression, number of apoptotic cells, phosphorylated p38 MAPK protein expression, and vascular cell adhesion molecule-1 protein expression while endothelial nitric oxide synthase protein expression was increased. In conclusion, they demonstrated that NO-NIF ameliorated ischemic skin flap necrosis by reducing oxidative stress, apoptosis, and endothelial dysfunction. NO-NIF is considered to be a candidate for the treatment of ischemic flap necrosis.

  8. Sternocleidomastoid Muscle Flap after Parotidectomy.

    PubMed

    Nofal, Ahmad Abdel-Fattah; Mohamed, Morsi

    2015-10-01

    Introduction Most patients after either superficial or total parotidectomy develop facial deformity and Frey syndrome, which leads to a significant degree of patient dissatisfaction. Objective Assess the functional outcome and esthetic results of the superiorly based sternocleidomastoid muscle (SCM) flap after superficial or total parotidectomy. Methods A prospective cohort study for 11 patients subjected to parotidectomy using a partial-thickness superiorly based SCM flap. The functional outcome (Frey syndrome, facial nerve involvement, and ear lobule sensation) and the esthetic results were evaluated subjectively and objectively. Results Facial nerve palsy occurred in 5 cases (45%), and all of them recovered completely within 6 months. The Minor starch iodine test was positive in 3 patients (27%), although only 1 (9%) subjectively complained of gustatory sweating. The designed visual analog score completed by the patients themselves ranged from 0 to 3 with a mean of 1.55 ± 0.93; the scores from the blinded evaluators ranged from 1 to 3 with a mean 1.64 ± 0.67. Conclusion The partial-thickness superiorly based SCM flap offers a reasonable cosmetic option for reconstruction following either superficial or total parotidectomy by improving the facial deformity. The flap also lowers the incidence of Frey syndrome objectively and subjectively with no reported hazard of the spinal accessory nerve.

  9. Force Generation by Flapping Foils

    NASA Astrophysics Data System (ADS)

    Bandyopadhyay, P. R.; Donnelly, M.

    1996-11-01

    Aquatic animals like fish use flapping caudal fins to produce axial and cross-stream forces. During WW2, German scientists had built and tested an underwater vehicle powered by similar flapping foils. We have examined the forces produced by a pair of flapping foils. We have examined the forced produced by a pair of flapping foils attached to the tail end of a small axisymmetric cylinder. The foils operate in-phase (called waving), or in anti-phase (called clapping). In a low-speed water tunnel, we have undertaken time-dependent measurements of axial and cross-stream forces and moments that are exerted by the vortex shedding process over the entire body. Phase-matched LDV measurements of vorticity-velocity vectors, as well as limited flow visualization of the periodic vortex shedding process have also been carried out. The direction of the induced velocity within a pair of shed vortices determines the nature of the forces produced, viz., thrust or drag or cross-stream forces. The clapping mode produces a widely dispersed symmetric array of vortices which results in axial forces only (thrust and rag). On the other hand, the vortex array is staggered in the waving mode and cross-stream (maneuvering) forces are then generated.

  10. The possibility for use of venous flaps in plastic surgery

    SciTech Connect

    Baytinger, V. F. Kurochkina, O. S. Selianinov, K. V.; Baytinger, A. V.; Dzyuman, A. N.

    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 no 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.

  11. The possibility for use of venous flaps in plastic surgery

    NASA Astrophysics Data System (ADS)

    Baytinger, V. F.; Kurochkina, O. S.; Selianinov, K. V.; Baytinger, A. V.; Dzyuman, A. N.

    2015-11-01

    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 no 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.

  12. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  13. 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... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  14. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  15. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  16. 14 CFR 23.697 - Wing flap controls.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flap controls. 23.697 Section 23.697... Systems § 23.697 Wing flap controls. (a) Each wing flap control must be designed so that, when the flap... with § 23.145(b)(3) necessitates wing flap retraction to positions that are not fully retracted,...

  17. Monitoring of intraoral free flaps with microdialysis.

    PubMed

    Nielsen, Henrik Toft; Gutberg, Nils; Birke-Sorensen, Hanne

    2011-10-01

    Because of the confined nature of their position, monitoring intraoral free flaps is a challenge, but it is essential to detect vascular complications in time to ensure the possibility of salvaging the flap. Microdialysis has been the standard technique of choice at the Department of Plastic Surgery, Aarhus University Hospital, since September 1998. In this study we present our experience of monitoring 78 intraoral free flaps. It is a retrospective evaluation of patients' casenotes from November 1998 to March 2008. Sixty-five of the 78 flaps healed without complications. Sixty-one of these showed no sign of ischaemia in the microdialysis values; in 4 cases the microdialysis system caused technical problems. Thirteen patients were reoperated on based on the results of microdialysis analysis, and in all but 2 cases critical ischaemia was found. Ten of the 11 critically ischaemic flaps were saved. The overall loss rate of flaps was 1.3%. The 2 flaps that were reoperated on but no critical ischaemia found were 2 fibular flaps during the time that we were learning how to monitor with microdialysis (1999 and 2000). Since then we have developed a decision algorithm for standard monitoring, and since 2000 we have had no false positive results. We have never lost a flap from neglected ischaemia. Our results show that microdialysis is a safe and reliable technique for postoperative monitoring of intraoral free flaps.

  18. Regulation of yeast DNA polymerase δ-mediated strand displacement synthesis by 5'-flaps.

    PubMed

    Koc, Katrina N; Stodola, Joseph L; Burgers, Peter M; Galletto, Roberto

    2015-04-30

    The strand displacement activity of DNA polymerase δ is strongly stimulated by its interaction with proliferating cell nuclear antigen (PCNA). However, inactivation of the 3'-5' exonuclease activity is sufficient to allow the polymerase to carry out strand displacement even in the absence of PCNA. We have examined in vitro the basic biochemical properties that allow Pol δ-exo(-) to carry out strand displacement synthesis and discovered that it is regulated by the 5'-flaps in the DNA strand to be displaced. Under conditions where Pol δ carries out strand displacement synthesis, the presence of long 5'-flaps or addition in trans of ssDNA suppress this activity. This suggests the presence of a secondary DNA binding site on the enzyme that is responsible for modulation of strand displacement activity. The inhibitory effect of a long 5'-flap can be suppressed by its interaction with single-stranded DNA binding proteins. However, this relief of flap-inhibition does not simply originate from binding of Replication Protein A to the flap and sequestering it. Interaction of Pol δ with PCNA eliminates flap-mediated inhibition of strand displacement synthesis by masking the secondary DNA site on the polymerase. These data suggest that in addition to enhancing the processivity of the polymerase PCNA is an allosteric modulator of other Pol δ activities.

  19. Pedicle Temporalis Fascial Flap with Axial Scalp Flap Obviates Need of Free Flap in Extensive Scalp Wound

    PubMed Central

    Khainga, S. O.

    2017-01-01

    Extensive scalp defect with exposed bone is best reconstructed with flaps. Majority of these wounds are now routinely reconstructed with free flaps in many centers. Free flaps however require lengthy operative time and may not be available to all patients, where possible less extensive options should thus be encouraged. A sixty-eight-year-old patient presented to us with a Marjolin's ulcer on the vertex of the scalp. After wide local excision a defect of about 17 cm and 12 cm was left. The defect was successfully covered with a combination of an ipsilateral pedicle temporalis fascial flap and an axial supraorbital scalp flap with good outcome. In conclusion wide defects of the scalp can be fully covered with a combination of local flaps. The axial scalp flap and the pedicle temporalis fascial flap where applicable provide an easy and less demanding option in covering such wounds. These flaps are reliable with good blood supply and have got less donor side morbidity. PMID:28194294

  20. The free iliac flap: a lateral modification of the free groin flap.

    PubMed

    Acland, R D

    1979-07-01

    A lateral modification of the free groin flap, called the free iliac flap, is presented. By moving the outline of the free groin flap laterally, so that the medial margin lies lateral to the underlying femoral triangle, a flap is obtained which is uniformly slender and which has a long vascular pedicle. The anatomical findings, a method for safe dissection of the superficial circumflex iliac vessels, and the results of 18 clinical cases are presented.

  1. Pressure Distribution Over Airfoils with Fowler Flaps

    NASA Technical Reports Server (NTRS)

    Wenzinger, Carl J; Anderson, Walter B

    1938-01-01

    Report presents the results of tests made of a Clark y airfoil with a Clark y Fowler flap and of an NACA 23012 airfoil with NACA Fowler flaps. Some of the tests were made in the 7 by 10-foot wind tunnel and others in the 5-foot vertical wind tunnel. The pressures were measured on the upper and lower surfaces at one chord section both on the main airfoils and on the flaps for several angles of attack with the flaps located at the maximum-lift settings. A test installation was used in which the model was mounted in the wind tunnel between large end planes so that two-dimensional flow was approximated. The data are given in the form of pressure-distribution diagrams and as plots of calculated coefficients for the airfoil-and-flap combinations and for the flaps alone.

  2. Freestyle Local Perforator Flaps for Facial Reconstruction.

    PubMed

    Lee, Jun Yong; Kim, Ji Min; Kwon, Ho; Jung, Sung-No; Shim, Hyung Sup; Kim, Sang Wha

    2015-01-01

    For the successful reconstruction of facial defects, various perforator flaps have been used in single-stage surgery, where tissues are moved to adjacent defect sites. Our group successfully performed perforator flap surgery on 17 patients with small to moderate facial defects that affected the functional and aesthetic features of their faces. Of four complicated cases, three developed venous congestion, which resolved in the subacute postoperative period, and one patient with partial necrosis underwent minor revision. We reviewed the literature on freestyle perforator flaps for facial defect reconstruction and focused on English articles published in the last five years. With the advance of knowledge regarding the vascular anatomy of pedicled perforator flaps in the face, we found that some perforator flaps can improve functional and aesthetic reconstruction for the facial defects. We suggest that freestyle facial perforator flaps can serve as alternative, safe, and versatile treatment modalities for covering small to moderate facial defects.

  3. Pectoralis major flap for head and neck reconstruction in era of free flaps.

    PubMed

    Kekatpure, V D; Trivedi, N P; Manjula, B V; Mathan Mohan, A; Shetkar, G; Kuriakose, M A

    2012-04-01

    The aim of this study was to evaluate factors affecting the selection of pectoralis major flap in the era of free tissue reconstruction for post ablative head and neck defects and flap associated complications. The records of patients who underwent various reconstructive procedures between July 2009 and December 2010 were retrospectively analysed. 147 reconstructive procedures including 79 free flaps and 58 pectoralis major flaps were performed. Pectoralis major flap was selected for reconstruction in 21 patients (36%) due to resource constrains, in 12 (20%) patients for associated medical comorbidities, in 11 (19%) undergoing extended/salvage neck dissections, and in 5 patients with vessel depleted neck and free flap failure salvage surgery. None of the flaps was lost, 41% of patients had flap related complications. Most complications were self-limiting and were managed conservatively. Data from this study suggest that pectoralis major flap is a reliable option for head and neck reconstruction and has a major role even in this era of free flaps. The selection of pectoralis major flap over free flap was influenced by patient factors in most cases. Resource constraints remain a major deciding factor in a developing country setting.

  4. Craniotomy flap osteomyelitis: a diagnostic approach

    SciTech Connect

    Blumenkopf, B.; Hartshorne, M.F.; Bauman, J.M.; Cawthon, M.A.; Patton, J.A.; Friedman, A.H.

    1987-01-01

    Nine cases of suspected craniotomy flap osteomyelitis evaluated by combined bone and gallium scanning are presented. In six cases, the clinical data were inconclusive and evaluation by radionuclide imaging provided an accurate negative diagnosis. The other three cases considered positive by this technique were proven infected at subsequent exploration and flap removal. The use of radionuclide bone and gallium imaging should be considered in cases of possible craniotomy flap osteomyelitis.

  5. Scaling Effects on Stern Flap Performance. Progress Report

    DTIC Science & Technology

    2009-09-01

    prototype stern flap on the USS RAMAGE ( DDG 61), the 11th destroyer of the DDG 51 Class, with associated stern flap evaluation trials, has provided...TERMS Stern flap scaling effects; DDG 61 stern flap performance trials; geosim model experiments 16. SECURITY CLASSIFICATION OF: a. REPORT...GUIDANCE FOR PROJECTING FULL-SCALE STERN FLAP PERFORMANCE 12 CONTINUED RESEARCH 17 DDG 51 Stern Flap Scaling Effects Study 17 Application to Other

  6. The Gradual Expansion Muscle Flap

    DTIC Science & Technology

    2014-01-01

    Summary: High energy open fractures of the tibia have traditionally been fraught with challenges to include bone comminution or loss, soft tissue...and subsequent case series that obviates the need of free tissue transfer while treating high energy type IIIB open tibia fractures by performing an...Key Words: shortening and angulation, Taylor Spatial Frame, III B tibia fracture , flap coverage (J Orthop Trauma 2014;28:e15 e20) INTRODUCTION High

  7. A comparative molecular dynamics study on BACE1 and BACE2 flap flexibility.

    PubMed

    Kumalo, H M; Soliman, Mahmoud E

    2016-10-01

    Beta-amyloid precursor protein cleavage enzyme1 (BACE1) and beta-amyloid precursor protein cleavage enzyme2 (BACE2), members of aspartyl protease family, are close homologs and have high similarity in their protein crystal structures. However, their enzymatic properties are different, which leads to different clinical outcomes. In this study, we performed sequence analysis and all-atom molecular dynamic (MD) simulations for both enzymes in their ligand-free states in order to compare their dynamical flap behaviors. This is to enhance our understanding of the relationship between sequence, structure and the dynamics of this protein family. Sequence analysis shows that in BACE1 and BACE2, most of the ligand-binding sites are conserved, indicative of their enzymatic property as aspartyl protease members. The other conserved residues are more or less unsystematically localized throughout the structure. Herein, we proposed and applied different combined parameters to define the asymmetric flap motion; the distance, d1, between the flap tip and the flexible region; the dihedral angle, φ, to account for the twisting motion and the TriCα angle, θ2 and θ1. All four combined parameters were found to appropriately define the observed "twisting" motion during the flaps different conformational states. Additional analysis of the parameters indicated that the flaps can exist in an ensemble of conformations, i.e. closed, semi-open and open conformations for both systems. However, the behavior of the flap tips during simulations is different between BACE1 and BACE2. The BACE1 active site cavity is more spacious as compared to that of BACE2. The analysis of 10S loop and 113S loop showed a similar trend to that of flaps, with the BACE1 loops being more flexible and less stable than those of BACE2. We believe that the results, methods and perspectives highlighted in this report would assist researchers in the discovery of BACE inhibitors as potential Alzheimer's disease therapies.

  8. Temporoparietal-occipital flap for facial reconstruction.

    PubMed

    Moretti, E; Garcia, F G

    2001-04-01

    Eight patients with an extensive facial defect of the masseter region were reconstructed with a temporoparietal- occipital rotation flap. This flap is vascularized by both the arteria auricularis posterior and the arteria occipitalis lateralis. These vessels have been sufficient to ensure viability of the entire flap. It is elevated and easily transposed to the masseter region because of the distensibility obtained from the posterior neck. This approach avoided the need for an unsightly skin graft at the site while providing tissue with hair follicles that blend well with the surrounding hair. This large flap offers cosmetic advantages over other techniques for coverage of facial defects in men.

  9. 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.

  10. Refining the intrinsic chimera flap: a review.

    PubMed

    Agarwal, Jayant P; Agarwal, Shailesh; Adler, Neta; Gottlieb, Lawrence J

    2009-10-01

    Reconstruction of complex tissue deficiencies in which each missing component is in a different spatial relationship to each other can be particularly challenging, especially in patients with limited recipient vessels. The chimera flap design is uniquely suited to reconstruct these deformities. Chimera flaps have been previously defined in many ways with 2 main categories: prefabricated or intrinsic. Herein we attempt to clarify the definition of a true intrinsic chimeric flap and provide examples of how these constructs provide a method for reconstruction of complex defects. The versatility of the intrinsic chimera flap and its procurement from 7 different vascular systems is described. A clarification of the definition of a true intrinsic chimera flap is described. In addition, construction of flaps from the lateral femoral circumflex, deep circumflex iliac, inferior gluteal, peroneal, subscapular, thoracodorsal, and radial arterial systems is described to showcase the versatility of these chimera flaps. A true intrinsic chimera flap must consist of more than a single tissue type. Each of the tissue components receives its blood flow from separate vascular branches or perforators that are connected to a single vascular source. These vascular branches must be of appropriate length to allow for insetting with 3-dimensional spatial freedom. There are a multitude of sites from which true intrinsic chimera flaps may be harvested.

  11. A water tunnel study of Gurney flaps

    NASA Technical Reports Server (NTRS)

    Neuhart, Dan H.; Pendergraft, Odis C., Jr.

    1988-01-01

    Several Gurney flap configurations were tested in the NASA Langley 16 x 24 inch Water Tunnel. These devices provided an increased region of attached flow on a wing upper surface relative to the wing without the flaps. The recirculation region behind the flap was visualized and shown to be consistent with hypotheses stated in previous research. Although the test Reynolds number for this study was several orders of magnitude below those in previous investigations, the effect of the Gurney flaps is in qualitative agreement with them. This is as would be expected from first order effects for high lift devices.

  12. Arterialized Venous Bone Flaps: An Experimental Investigation

    PubMed Central

    Borumandi, Farzad; Higgins, James P.; Buerger, Heinz; Vasilyeva, Anna; Benlidayi, Memmet Emre; Sencar, Leman; Gaggl, Alexander

    2016-01-01

    In arterialized venous flaps (AVFs) the venous network is used to revascularize the flap. While the feasibility of AVFs in soft tissues has been reported there is no study on osseous AVFs. In this study we aim to assess the flap survival of osseous AVFs in a pig model. Medial femoral condyle flaps were elevated in 18 pigs. Three groups were created: AVF (n = 6), conventional arterial flap (cAF, n = 6) and bone graft (BG, n = 6). The AVFs were created by anastomosis of genicular artery with one vena comitans while leaving one efferent vein for drainage. After 6 months the specimens were harvested. The histology and histomorphometry of of the bone in cAF and AVF was significantly superior to bone grafts with a higher bone volume in AVFs (p = 0.01). This study demonstrates that osseous free flaps may be supported and survive using the technique of arterialization of the venous network. The concept of AVFs in osseous flaps may be feasible for revascularization of free flaps with an inadequate artery but well developed veins. Further experimental and clinical studies are needed to assess the feasibility of clinical use of arterialized venous bone flaps. PMID:27558705

  13. Microsurgical free flaps: Controversies in maxillofacial reconstruction

    PubMed Central

    George, Rinku K.; Krishnamurthy, Arvind

    2013-01-01

    Reconstructive microsurgery for oral and maxillofacial (OMF) defects is considered as a niche specialty and is performed regularly only in a handful of centers. Till recently the pectoralis major myocutaneous flap (PMMC) was considered to be the benchmark for OMF reconstruction. This philosophy is changing fast with rapid advancement in reconstructive microsurgery. Due to improvement in instrumentation and the development of finer techniques of flap harvesting we can positively state that microsurgery has come of age. Better techniques, microscopes and micro instruments enable us to do things previously unimaginable. Supramicrosurgery and ultrathin flaps are a testimony to this. Years of innovation in reconstructive microsurgery have given us a reasonably good number of very excellent flaps. Tremendous work has been put into producing some exceptionally brilliant research articles, sometimes contradicting each other. This has led to the need for clarity in some areas in this field. This article will review some controversies in reconstructive microsurgery and analyze some of the most common microvascular free flaps (MFF) used in OMF reconstruction. It aims to buttress the fact that three flaps-the radial forearm free flap (RFFF), anterolateral thigh flap (ALT) and fibula are the ones most expedient in the surgeon's arsenal, since they can cater to almost all sizeable defects we come across after ablative surgery in the OMF region. They can thus aptly be titled as the workhorses of OMF reconstruction with regard to free flaps. PMID:23662264

  14. Pressure Available for Cooling with Cowling Flaps

    NASA Technical Reports Server (NTRS)

    Stickle, George W; Naiman, Irven; Crigler, John L

    1941-01-01

    Report presents the results of a full-scale investigation conducted in the NACA 20-foot tunnel to determine the pressure difference available for cooling with cowling flaps. The flaps were applied to an exit slot of smooth contour at 0 degree flap angle. Flap angles of 0 degree, 15 degrees, and 30 degrees were tested. Two propellers were used; propeller c which has conventional round blade shanks and propeller f which has airfoil sections extending closer to the hub. The pressure available for cooling is shown to be a direct function of the thrust disk-loading coefficient of the propeller.

  15. 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

  16. Effects of perforated flap surfaces and screens on acoustics of a large externally blown flap model

    NASA Technical Reports Server (NTRS)

    Burns, R. J.; Mckinzie, D. J., Jr.; Wagner, J. M.

    1976-01-01

    Various model geometries and combinations of perforated flap surfaces and screens mounted close to the flap surfaces were studied for application to jet-flap noise attenuation for externally blown flap, under-the-wing aircraft. The efforts to reduce jet-flap interaction noise were marginally successful. Maximum attenuations of less than 4 db in overall sound pressure level were obtained in the flyover plane. Noise reductions obtained in the low-to-middle-frequency ranges (up to 7 db) were generally offset by large increases in high-frequency noise (up to 20 db).

  17. Energy management - The delayed flap approach

    NASA Technical Reports Server (NTRS)

    Bull, J. S.

    1976-01-01

    Flight test evaluation of a Delayed Flap approach procedure intended to provide reductions in noise and fuel consumption is underway using the NASA CV-990 test aircraft. Approach is initiated at a high airspeed (240 kt) and in a drag configuration that allows for low thrust. The aircraft is flown along the conventional ILS glide slope. A Fast/Slow message display signals the pilot when to extend approach flaps, landing gear, and land flaps. Implementation of the procedure in commercial service may require the addition of a DME navigation aid co-located with the ILS glide slope transmitter. The Delayed Flap approach saves 250 lb of fuel over the Reduced Flap approach, with a 95 EPNdB noise contour only 43% as large.

  18. Scrubbing noise of externally blown flaps

    NASA Technical Reports Server (NTRS)

    Fink, M. R.

    1975-01-01

    An experimental study was conducted to examine the aeroacoustic mechanism that produces externally blown flap (EBF) scrubbing noise, i.e. a surface-radiated noise which is generally strongest normal to UTW deflected flaps. Scrubbing noise was not radiated from portions of the surface adjacent to strong, locally coherent turbulent eddies. Instead, scrubbing noise seemed to come from weak loading fluctuations that were coherent along the scrubbed span. These loading fluctuations probably were induced by the convected large-scale vortex structure of the attached exhaust jet. Deflecting a UTW flap would reduce the distance between the vortex trajectory and the flap surface, increasing the resulting dipole noise and rotating its directivity. In contrast, deflecting a USB flap would increase this distance, so that observable scrubbing noise would be radiated only from the undeflected forward portion of the wing.

  19. White light spectroscopy for free flap monitoring.

    PubMed

    Fox, Paige M; Zeidler, Kamakshi; Carey, Joseph; Lee, Gordon K

    2013-03-01

    White light spectroscopy non-invasively measures hemoglobin saturation at the capillary level rendering an end-organ measurement of perfusion. We hypothesized this technology could be used after microvascular surgery to allow for early detection of ischemia and thrombosis. The Spectros T-Stat monitoring device, which utilizes white light spectroscopy, was compared with traditional flap monitoring techniques including pencil Doppler and clinical exam. Data were prospectively collected and analyzed. Results from 31 flaps revealed a normal capillary hemoglobin saturation of 40-75% with increase in saturation during the early postoperative period. One flap required return to the operating room 12 hours after microvascular anastomosis. The T-stat system recorded an acute decrease in saturation from ~50% to less than 30% 50 min prior to identification by clinical exam. Prompt treatment resulted in flap salvage. The Spectros T-Stat monitor may be a useful adjunct for free flap monitoring providing continuous, accurate perfusion assessment postoperatively.

  20. Microvascular free flaps in skull base reconstruction.

    PubMed

    Herr, Marc W; Lin, Derrick T

    2013-01-01

    The anatomical challenges of skull base surgery are well known. Furthermore, ablative and traumatic defects in this region produce complex reconstructive problems with a high risk of significant postoperative morbidity and mortality. Over the past two decades, microvascular free tissue reconstruction following open resection has been shown to improve outcomes and reduce complication rates when compared to the traditional use of pedicled flaps. The increasing use of free tissue transfer has been further strengthened by improved technical expertise and high flap success rates. Since the size and type of free tissue to be utilized must be individualized to each defect, the accomplished reconstructive surgeon should be extremely versatile and, by extension, facile with a several types of free flaps. Thus, four of the most commonly used flaps--the rectus abdominis, radial forearm, latissimus dorsi and anterolateral thigh flaps--are discussed.

  1. Peroneal Flap: Clinical Application and Cadaveric Study

    PubMed Central

    Ha, Yooseok; Yeo, Kwan Koo; Piao, Yibo

    2017-01-01

    Background The goal of this study was to investigate the anatomy of the peroneal artery and its perforators, and to report the clinical results of reconstruction with peroneal artery perforator flaps. Methods The authors dissected 4 cadaver legs and investigated the distribution, course, origin, number, type, and length of the perforators. Peroneal artery perforator flap surgery was performed on 29 patients. Results We identified 19 perforators in 4 legs. The mean number of perforators was 4.8 per leg, and the mean length was 4.8 cm. Five perforators were found proximally, 9 medially, and 5 distally. We found 12 true septocutaneous perforators and 7 musculocutaneous perforators. Four emerged from the posterior tibia artery, and 15 were from the peroneal artery. The peroneal artery perforator flap was used in 29 patients. Retrograde island peroneal flaps were used in 8 cases, anterograde island peroneal flaps in 5 cases, and free peroneal flaps in 16 cases. The mean age was 59.9 years, and the defect size ranged from 2.0 cm×4.5 cm to 8.0 cm×8.0 cm. All the flaps survived. Five flaps developed partial skin necrosis. In 2 cases, a split-thickness skin graft was performed, and the other 3 cases were treated without any additional procedures. Conclusions The peroneal artery perforator flap is a good alternative for the reconstruction of soft tissue defects, with a constant and reliable vascular pedicle, thin and pliable skin, and the possibility of creating a composite tissue flap. PMID:28352602

  2. DIEP flap sentinel skin paddle positioning algorithm.

    PubMed

    Laporta, Rosaria; Longo, Benedetto; Sorotos, Michail; Pagnoni, Marco; Santanelli Di Pompeo, Fabio

    2015-02-01

    Although clinical examination alone or in combination with other techniques is the only ubiquitous method for flap monitoring, it becomes problematic with buried free-tissue transfer. We present a DIEP flap sentinel skin paddle (SSP) positioning algorithm and its reliability is also investigated using a standardized monitoring protocol. All DIEP flaps were monitored with hand-held Doppler examination and clinical observation beginning immediately after surgery in recovery room and continued postoperatively at the ward. Skin paddle (SP) position was preoperatively drawn following mastectomy type incisions; in skin-sparing mastectomies types I-III a small SP (sSP) replaces nipple-areola complex; in skin-sparing mastectomy type IV, SSP is positioned between wise-pattern branches while in type V between medial/lateral branches. In case of nipple-sparing mastectomy SSP is positioned at inframammary fold or in lateral/medial branches of omega/inverted omega incision if used. Three hundred forty-seven DIEP flap breast reconstructions were reviewed and stratified according to SP type into group A including 216 flaps with large SP and group B including 131 flaps with SSP and sSP. Sixteen flaps (4.6%) were taken back for pedicle compromise, 13 of which were salvaged (81.25%), 11 among 13 from group A and 2 among 3 from group B. There was no statistical difference between the groups concerning microvascular complication rate (P = 0.108), and time until take-back (P = 0.521) and flap salvage rate (P = 0.473) resulted independent of SP type. Our results suggest that early detection of perfusion impairment and successful flaps salvage could be achieved using SSP for buried DIEP flap monitoring, without adjunctive expensive monitoring tests.

  3. Use of rotation scalp flaps for treatment of occipital baldness.

    PubMed

    Juri, J; Juri, C; Arufe, H N

    1978-01-01

    We have used 25 rotation scalp flaps to treat occipital baldness associated with fronto-parietal baldness (the third flap), and 35 such flaps for the correction of isolated occipital baldness. We have not had any flap necrosis, and our patients have been well satisfied with the results of this surgery.

  4. The fleur-de-lis upper gracilis flap for breast reconstruction: flap design and outcome.

    PubMed

    McKane, Brice W; Korn, Peter T

    2012-10-01

    We evaluated a fleur-de-lis design for the gracilis myocutaneous flap to improve flap volume for breast reconstruction. Thirty-one flaps were used in 17 consecutive patients undergoing the procedure for either thin body habitus (23 flaps) or prior abdominal surgery (8 flaps). The flap success rate was 100%. The fleur-de-lis flap provided proportionate breast reconstructions in all patients. Complications included 6 (19.3%) donor-site dehiscence and 4 (12.9%) episodes of cellulitis. Applying a negative pressure dressing to the donor site (n=26) significantly reduced the initially high dehiscence rate to 7.7% (P<0.01). There was no incidence of lower extremity edema or sensory loss. The fleur-de-lis gracilis flap can be performed with a low flap related complication rate and acceptable donor-site morbidity. Because of its standardized flap design, improved volume, and favorable breast shaping, it may allow autologous breast reconstruction to be offered to a greater number of patients.

  5. 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.

  6. Hydrodynamic schooling of flapping swimmers

    DOE PAGES

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; ...

    2015-10-06

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in amore » group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.« less

  7. Hydrodynamic schooling of flapping swimmers

    SciTech Connect

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-06

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. Lastly, these results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

  8. Hydrodynamic schooling of flapping swimmers

    PubMed Central

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-01-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing–wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups. PMID:26439509

  9. Hydrodynamic schooling of flapping swimmers

    NASA Astrophysics Data System (ADS)

    Becker, Alexander D.; Masoud, Hassan; Newbolt, Joel W.; Shelley, Michael; Ristroph, Leif

    2015-10-01

    Fish schools and bird flocks are fascinating examples of collective behaviours in which many individuals generate and interact with complex flows. Motivated by animal groups on the move, here we explore how the locomotion of many bodies emerges from their flow-mediated interactions. Through experiments and simulations of arrays of flapping wings that propel within a collective wake, we discover distinct modes characterized by the group swimming speed and the spatial phase shift between trajectories of neighbouring wings. For identical flapping motions, slow and fast modes coexist and correspond to constructive and destructive wing-wake interactions. Simulations show that swimming in a group can enhance speed and save power, and we capture the key phenomena in a mathematical model based on memory or the storage and recollection of information in the flow field. These results also show that fluid dynamic interactions alone are sufficient to generate coherent collective locomotion, and thus might suggest new ways to characterize the role of flows in animal groups.

  10. Critical Mach Numbers of Thin Airfoil Sections with Plain Flaps

    NASA Technical Reports Server (NTRS)

    Pardee, Otway O'm.; Heaslet, Max A.

    1946-01-01

    Critical Mach number as function of lift coefficient is determined for certain moderately thick NACA low-drag airfoils. Results, given graphically, included calculations on same airfoil sections with plain flaps for small flap deflections. Curves indicate optimum critical conditions for airfoils with flaps in such form that they can be compared with corresponding results for zero flap deflections. Plain flaps increase life-coefficient range for which critical Mach number is in region of high values characteristic of low-drag airfoils.

  11. Preputial flaps to correct buried penis.

    PubMed

    Chu, Chih-Chun; Chen, Yi-Hsin; Diau, Guan-Yeu; Loh, Ih-Wei; Chen, Ke-Chi

    2007-11-01

    The authors developed a preputial skin flap technique to correct the buried penis which was simple and practical. This simple procedure can be applied to most boys with buried penis. In the last 3 years, we have seen 12 boys with buried penis and have been treated by using preputial flaps. The mean age is about 5.1 (from 3 to 12). By making a longitudinal incision on the ventral side of penis, the tightness of the foreskin is released and leave a diamond-shaped skin defect. It allows the penile shaft to extend out. A circumferential incision is made about 5 mm proximal to the coronal sulcus. Pedicled preputial flaps are obtained leaving optimal penile skin on the dorsal side. The preputial skin flaps are rotated onto the ventral side and tailored to cover the defect. All patients are followed for at least 3 months. Edema and swelling on the flaps are common, but improves with time. None of our patients need a second operation. The preputial flaps technique is a simple technique which allows surgeons to deal with most cases of buried penis by tailoring the flaps providing good cosmetic and functional results.

  12. A review of propeller flaps for distal lower extremity soft tissue reconstruction: Is flap loss too high?

    PubMed

    Nelson, Jonas A; Fischer, John P; Brazio, Philip S; Kovach, Stephen J; Rosson, Gedge D; Rad, Ariel N

    2013-10-01

    Soft tissue coverage in the distal lower extremity remains a significant challenge. While free flaps are often utilized for larger defects, local perforator-based propeller flaps may be ideal for smaller wounds requiring coverage. Propeller flaps can provide excellent form and function for both traumatic and atraumatic defects with minimal donor site morbidity but can have concerning rates of flap loss. We reviewed the literature, identifying 21 studies presenting 310 propeller flaps for distal lower extremity reconstruction. Total flap necrosis was noted in 5.5% of flaps, with partial necrosis in 11.6%. While these flaps do enable transfer of local, healthy tissue to the defect site without the need for a microsurgical anastomosis, this rate of flap loss is concerning and appropriate patient selection is crucial. This review provides a brief history and overview of the clinical application and research into distal lower extremity perforator propeller flaps to place this technique into a clinical context.

  13. Pedicled Supraclavicular Artery Island Flap Versus Free Radial Forearm Flap for Tongue Reconstruction Following Hemiglossectomy.

    PubMed

    Zhang, Senlin; Chen, Wei; Cao, Gang; Dong, Zhen

    2015-09-01

    This study investigated the tongue function and donor-site morbidity of patients with malignant tumors who had undergone immediate flap reconstruction surgery. Twenty-seven patients who had undergone immediate reconstruction after hemiglossectomy were observed. Twelve patients were reconstructed using the pedicled supraclavicular artery island flap (PSAIF) and 15 patients using the free radial forearm flap (FRFF). Flap survival, speech and swallowing function, and donor-site morbidity at the 6-month follow-up were evaluated. All the flaps were successfully transferred. No obvious complications were found in either the transferred flaps or donor regions. Age, sex, defect extent, speech and swallowing function were comparable between the 2 groups. Donor-site complications were less frequent with PSAIF reconstruction than FRFF reconstruction. The PSAIF is reliable and well suited for hemiglossectomy defect. It has few significant complications, and allows preservation of oral function.

  14. Reconstruction of lateral forefoot using reversed medial plantar flap with free anterolateral thigh flap.

    PubMed

    Fujioka, Masaki; Hayashida, Kenji; Senju, Chikako

    2014-01-01

    Skin defects of the heel have frequently been reconstructed using the medial plantar flap; however, forefoot coverage has remained a challenge, because the alternatives for flap coverage have been very limited. We describe a case of malignant melanoma on the lateral forefoot that was radically removed and reconstructed successfully with a distally based medial plantar flap, together with a free anterolateral thigh flap. The advantages of this flap include that it does not reduce the vascular supply to the foot owing to reconstruction of the medial plantar vascular systems, reduces the risk of flap congestion, minimizes donor site morbidity, and enables the transport of structurally similar tissues to the plantar forefoot. We believe this technique is a reasonable reconstructive option for large lateral plantar forefoot defects.

  15. Monitoring of free TRAM flaps with microdialysis.

    PubMed

    Udesen, A; Løntoft, E; Kristensen, S R

    2000-02-01

    The aim of this investigation was to follow the metabolism of free TRAM flaps using microdialysis. Microdialysis is a new sampling technique that provide opportunities to follow the biochemistry in specific organs or tissues. A double-lumen microdialysis catheter or probe, with a dialysis membrane at the end, is introduced into the specific tissue. Perfusion fluid is slowly pumped through the catheter and equilibrates across the membrane with surrounding extracellular concentrations of low molecular weight substances. The dialysate is collected in microvials and analyzed by an instrument using very small volumes. Glucose, glycerol, and lactate concentrations were measured in the flaps and compared with those in a reference catheter that was placed subcutaneously in the femur. The investigation continued 72 hr postoperatively. The study group consisted of 14 women who underwent reconstruction with a free TRAM flap, and one woman with a double TRAM flap. During flap ischemia, the concentration of glucose was reduced, while the lactate and glycerol levels increased. The differences between the flaps and controls were statistically highly significant. After reperfusion of the flaps, the concentrations of glucose, lactate, and glycerol approached normal. One flap failed because of an arterial anastomosis thrombosis. This was clearly demonstrated by the samples from the microdialysis: the concentration of glucose fell to an unmeasurable level; the concentration of lactate increased for a period before it stopped due to lack of glucose; and the concentration of glycerol increased to a very high level, probably because ischemia caused damage to the cell membranes of which glycerol is an important part. The authors concluded that microdialysis can detect ischemia in free flaps at an early stage, making early surgical intervention possible.

  16. Dynamic response of a piezoelectric flapping wing

    NASA Astrophysics Data System (ADS)

    Kumar, Alok; Khandwekar, Gaurang; Venkatesh, S.; Mahapatra, D. R.; Dutta, S.

    2015-03-01

    Piezo-composite membranes have advantages over motorized flapping where frequencies are high and certain coupling between bending and twisting is useful to generate lift and forward flight. We draw examples of fruit fly and bumble bee. Wings with Piezo ceramic PZT coating are realized. The passive mechanical response of the wing is characterized experimentally and validated using finite element simulation. Piezoelectric actuation with uniform electrode coating is characterized and optimal frequencies for flapping are identified. The experimental data are used in an empirical model and advanced ratio for a flapping insect like condition for various angular orientations is estimated.

  17. 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.

  18. Foot and ankle reconstruction: an experience on the use of 14 different flaps in 226 cases.

    PubMed

    Zhu, Yue-Liang; Wang, Yi; He, Xiao-Qing; Zhu, Min; Li, Fu-Bin; Xu, Yong-Qing

    2013-11-01

    The aim of this report was to present our experience on the use of different flaps for soft tissue reconstruction of the foot and ankle. From 2007 to 2012, the soft tissue defects of traumatic injuries of the foot and ankle were reconstructed using 14 different flaps in 226 cases (162 male and 64 female). There were 62 pedicled flaps and 164 free flaps used in reconstruction. The pedicled flaps included sural flap, saphenous flap, dorsal pedal neurocutaneous flap, pedicled peroneal artery perforator flap, pedicled tibial artery perforator flap, and medial plantar flap. The free flaps were latissimus musculocutaneous flap, anterolateral thigh musculocutaneous flap, groin flap, lateral arm flap, anterolateral thigh perforator flap, peroneal artery perforator flap, thoracdorsal artery perforator flap, medial arm perforator flap. The sensory nerve coaptation was not performed for all of flaps. One hundred and ninety-four cases were combined with open fractures. One hundred and sixty-two cases had tendon. Among 164 free flaps, 8 flaps were completely lost, in which the defects were managed by the secondary procedures. Among the 57 flaps for plantar foot coverage (25 pedicled flaps and 32 free flaps), ulcers were developed in 5 pedicled flaps and 6 free flaps after weight bearing, and infection was found in 14 flaps. The donor site complications were seen in 3 cases with the free anterolateral thigh perforator flap transfer. All of limbs were preserved and the patients regained walking and daily activities. All of patients except for one regained protective sensation from 3 to 12 months postoperatively. Our experience showed that the sural flap and saphenous flap could be good options for the coverage of the defects at malleolus, dorsal hindfoot and midfoot. Plantar foot, forefoot and large size defects could be reconstructed with free anterolateral thigh perforator flap. For the infected wounds with dead spce, the free latissimus dorsi musculocutaneous flap remained to

  19. Paramedian forehead flap combined with hinge flap for nasal tip reconstruction*

    PubMed Central

    Cerci, Felipe Bochnia; Dellatorre, Gerson

    2016-01-01

    The paramedian forehead flap is a great option for restoration of complex nasal defects. For full-thickness defects, it may be used alone or in combination with other methods. We present a patient with a basal cell carcinoma on the distal nose treated by Mohs micrographic surgery, and a resulting full-thickness defect repaired with paramedian forehead flap combined with a hinge flap. For optimal results with the paramedian forehead flap, adequate surgical planning, patient orientation and meticulous surgical technique are imperative.

  20. Latissimus Dorsi Myocutaneous Flap for Breast Reconstruction: Bad Rap or Good Flap?

    PubMed Central

    Perdikis, Galen; Koonce, Stephanie; Collis, George; Eck, Dustin

    2011-01-01

    Objective: This article serves to review latissimus dorsi myocutaneous flap as an option for breast reconstruction postmastectomy. Since the introduction of the latissimus dorsi myocutaneous flap in the late 1970s, its use has always been as a secondary technique, particularly after the development of the transverse rectus abdominus myocutaneous flap in the 1980s. Methods: A literature review of the history of latissimus dorsi myocutaneous flap utilized for breast reconstruction as well as a review of our institution's experience with latissimus dorsi myocutaneous flap and tissue expander placement was performed. Results: There remains a paucity of published studies investigating latissimus dorsi myocutaneous flap for breast reconstruction. Most studies have small numbers and do not utilize tissue expanders. More recently several small studies have been published that show acceptably low complication rates with aesthetically pleasing outcomes when latissimus dorsi myocutaneous flap is employed with a tissue expander. At our institution, we have employed latissimus dorsi myocutaneous flap with tissue expander placement for both delayed and immediate reconstruction with subsequent replacement with a permanent implant with a capsular contraction rate of 10.5%. Our data and others more recently published demonstrate very acceptable capsular contracture rates and aesthetic outcomes, particularly when an expander is utilized. Conclusion: The latissimus dorsi myocutaneous flap remains an excellent choice for breast reconstruction with a low risk of complications. PMID:22031843

  1. Diabetic foot reconstruction using free flaps increases 5-year-survival rate.

    PubMed

    Oh, Tae Suk; Lee, Ho Seung; Hong, Joon Pio

    2013-02-01

    The purpose of this study was to evaluate the outcome of the diabetic foot reconstructed with free flaps and analyse the preoperative risk factors. This study reviews 121 cases of reconstructed diabetic foot in 113 patients over 9 years (average follow-up of 53.2 months). Patients' age ranged from 26 to 78 years (average, 54.6 years). Free flaps used were anterolateral thigh (ALT, 90), superficial circumflex iliac artery perforator (SCIP, 20), anteromedial thigh (AMT, 5), upper medial thigh (UMT, 3), and other perforator free flaps (3). Correlation between the surgical outcome and preoperative risk factors were analysed using logistic regression model. Total loss was seen in 10 cases and 111 free-tissue transfers were successful (flap survival rate of 91.7%). During follow-up, limb was eventually lost in 17 patients and overall limb salvage rate was 84.9% and the 5-year survival was 86.8%. Correlation between flap loss and 14 preoperative risk factors (computed tomography (CT) angiogram showing intact numbers of major vessels, history of previous angioplasty, peripheral arterial disease (PAD), heart problem, chronic renal failure (CRF), American Society of Anaesthesiologists (ASA) physical status classification system, smoking, body mass index (BMI), HBA1c, lymphocyte count, ankle-brachial index (ABI), osteomyelitis, C-reactive protein (CRP) level and whether taking immunosuppressive agents) were analysed. Significant odds ratio were seen in patients who underwent lower extremity angioplasties (odds ratio: 17.590, p<0.001), with PAD (odds ratio: 10.212, p=0.032) and taking immunosuppressive agents after kidney transplantation (odds ratio: 4.857, p<0.041). Diabetic foot reconstruction using free flaps has a high chance for success and significantly increases the 5-year survival rate. Risk factors such as PAD, history of angioplasties in the extremity and using immunosuppressive agents after transplant may increase the chance for flap loss.

  2. A Flap Endonuclease (TcFEN1) Is Involved in Trypanosoma cruzi Cell Proliferation, DNA Repair, and Parasite Survival.

    PubMed

    Ponce, Ivan; Aldunate, Carmen; Valenzuela, Lucia; Sepúlveda, Sofia; Garrido, Gilda; Kemmerling, Ulrike; Cabrera, Gonzalo; Galanti, Norbel

    2016-12-09

    FLAP endonucleases (FEN) are involved both in DNA replication and repair by processing DNA intermediaries presenting a nucleotide flap using its phosphodiesterase activity. In spite of these important functions in DNA metabolism, this enzyme was not yet studied in Trypanosomatids. Trypanosoma cruzi, the ethiological agent of Chagas disease, presents two dividing cellular forms (epimastigote and amastigote) and one non-proliferative, infective form (trypomastigote). The parasite survives DNA damage produced by reactive species generated in its hosts. The activity of a T. cruzi FLAP endonuclease (TcFEN1) was determined in the three cellular forms of the parasite using a DNA substrate generated by annealing three different oligonucleotides to form a double-stranded DNA with a 5' flap in the middle. This activity showed optimal pH and temperature similar to other known FENs. The substrate cut by the flap endonuclease activity could be ligated by the parasite generating a repaired DNA product. A DNA flap endonuclease coding sequence found in the T. cruzi genome (TcFEN1) was cloned, inserted in parasite expression vectors and transfected to epimastigotes. The purified native recombinant protein showed DNA flap endonuclease activity. This endonuclease was found located in the parasite nucleus of transfected epimastigotes and its over-expression increased both parasite proliferation and survival to H2 O2 . The presence of a flap endonuclease activity in T. cruzi and its nuclear location are indicative of the participation of this enzyme in DNA processing of flap fragments during DNA replication and repair in this parasite of ancient evolutive origin. J. Cell. Biochem. 9999: 1-11, 2016. © 2016 Wiley Periodicals, Inc.

  3. What’s the remedy for the distal necrosis of DIEP flap, better venous drain or more arterial supply?

    PubMed Central

    Wei, Jiao; He, Jinguang; Wang, Tao; Liu, Ying; Xu, Hua; Dong, Jiasheng

    2017-01-01

    Background We developed a novel pedicled DIEP flap model in rat to explore the possible remedy for the distal necrosis of the flap. Methods A deep inferior epigastric perforator (DIEP) flap, based on the second right cranial perforator (P2) as the main pedicle, was elevated in 48 Sprague-Dawley rats. The rats were randomized into 4 groups: group I, the left P2 remaining intact as supercharging; group II, the left P2 artery alone kept as supercharging; group III, the left P2 vein alone kept as supercharging; group IV, no supercharging. Transcutaneous oxygen pressure (TcPO2) and transcutaneous carbon dioxide pressure (TcPCO2) were measured immediately after flap elevation, protein level of Hif-1a was measured 48 hours later, and flap survival was assessed 7 days postoperatively. Results Blockade of artery led to significantly lower TcPO2, higher TcPCO2, and higher expression level of Hif-1a in the distal side of the flap in group III and group IV, than those of group I and group II. At 7 days post surgery, significantly lower flap survival rates were observed in group III (81.9 ± 5.7%) and group IV (78.4 ± 6.5%), compared to observed in group I (97.2 ± 3.0%) and group II (94.2 ± 6.2%). Conclusions It might be arterial insufficiency, not venous congestion, which mainly caused the distal necrosis of the DIEP flap in rat. Arterial instead of venous supercharging might be a more effective procedure that improves circulation to zone IV of the flap. PMID:28187214

  4. A dynamical system for interacting flapping swimmers

    NASA Astrophysics Data System (ADS)

    Oza, Anand; Ramananarivo, Sophie; Ristroph, Leif; Shelley, Michael

    2015-11-01

    We present the results of a theoretical investigation into the dynamics of interacting flapping swimmers. Our study is motivated by the recent experiments of Becker et al., who studied a one-dimensional array of self-propelled flapping wings that swim within each other's wakes in a water tank. They discovered that the system adopts certain ``schooling modes'' characterized by specific spatial phase relationships between swimmers. To rationalize these phenomena, we develop a discrete dynamical system in which the swimmers are modeled as heaving airfoils that shed point vortices during each flapping cycle. We then apply our model to recent experiments in the Applied Math Lab, in which two tandem flapping airfoils are free to choose both their speed and relative positions. We expect that our model may be used to understand how schooling behavior is influenced by hydrodynamics in more general contexts. Thanks to the NSF for its support.

  5. The flow around a flapping foil

    NASA Astrophysics Data System (ADS)

    Mandujano, Francisco; Malaga, Carlos

    2016-11-01

    The flow around a two-dimensional flapping foil immersed in a uniform stream is studied numerically using a Lattice-Boltzmann model, for Reynolds numbers between 100 and 250, and flapping Strouhal numbers between 0 . 01 and 0 . 6 . The computation of the hydrodynamic force on the foil is related to the wake structure. When the foil's is fixed in space, numerical results suggest a relation between drag coefficient behaviour and the flapping frequency which determines the transition from the von Kármán to the inverted von Kármán wake. When the foil is free of translational motion up-stream swimming at constant speed is observed at certain values of the flapping Strouhal. This work was partially supported by UNAM-DGAPA-PAPIIT Grant Number IN115316.

  6. Lower extremity free flaps: a review

    PubMed Central

    Wells, Mark D.; Bowen, C. Vaughan; Manktelow, Ralph T.; Graham, John; Boyd, J. Brian

    1996-01-01

    Objective To identify factors related to free-flap coverage of lower extremity fractures that are linked to a negative outcome. Design A chart review. Setting A large microsurgical referral centre. Patients From 1981 to 1989, the records of all patients who underwent free-tissue transfer to the lower extremity with more than 1 year of follow-up were selected. From this was drawn a subgroup of 49 patients (mean age, 36 years) who had tibial fractures (55% were motor vehicle injuries) and in almost all cases established soft-tissue or bony defects. They formed the study group. Intervention Free-flap transfer. Outcome Measures Factors that might be associated with free-flap failure: mechanism of injury, grade of tibial fracture, history of smoking, diabetes, peripheral vascular disease, ischemic heart disease, vascular compromise in the leg preoperatively, recipient artery used, type of anastomosis, and hypertension or hypotension intraoperatively. Results Type IIIB tibial fractures were the most frequent (67%) and carried a significantly (p = 0.02) higher risk of free-flap failure than other types of fracture. Patients underwent a mean of four procedures before referral for free-tissue transfer. The mean time from injury to flap coverage was 1006 days. Stable, long-term coverage of the free flaps was achieved in 78% of patients. Wound breakdown was most often caused by recurrent osteomyelitis (65%). Seventy-four percent of the fractures healed. The amputation rate was 10%. Four patients required repeat free-flap transfer for limb salvage. Conclusion Only the grade of tibial fracture could be significantly related to postoperative free-flap failure. PMID:8640624

  7. Predictable Pattern Digital Artery Perforator Flap

    PubMed Central

    Epameinondas, Kostopoulos; Christos, Agiannidis; Petros, Konofaos; Avraam, Dounavis; Othon, Papadopoulos; Vincent, Casoli

    2016-01-01

    Background: The proper digital arteries as any other axial vessel give rise to multiple cutaneous perforators either volar or dorsal along their course. Their identification is performed with Doppler flowmetry. The vasculo-cutano-tendino-osseous complex (VCTOC), which was described by the senior authors, was responsible for the vascularization of all digital anatomic structures (extensor apparatus, skin, periosteum). Their consistent appearance to well measured distances from the digital joints led the way to the present clinical study for highlighting this described anatomy in-vivo and demonstrating the predictability in digital artery perforator (DAP) flap harvest. Methods: From November 2012 to March 2014, fifteen patients underwent reconstruction with a predictable pattern digital artery perforator flap (PPDAP), based on the previously described VCTOC mapping, for digital lesions secondary to tumor extirpation. Flaps were designed as V-Y advancement or propeller type. Postoperative control concerned flap viability and digital function. Results: Seven males and 8 females underwent elective surgery using PPDAP flaps for digital defects following tumor extirpation. The diameter of the defect ranged from 0.5 to 1.5 cm. The vast majority of the lesions were identified on the right hand, the index, the ring finger and the distal phalanx. All flaps survived without signs of venous congestion. No functional digital problems were observed during follow up (mean of 77 months). A minor wound dehiscence presented in one patient. Conclusions: Authors introduced the concept of a “predictable pattern” in the surgery of perforator flaps in the digits. These flaps are reliable and could be a valuable reconstructive option. PMID:27418896

  8. 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

  9. A method for constructing vascularized muscle flap.

    PubMed

    Shandalov, Yulia; Egozi, Dana; Freiman, Alina; Rosenfeld, Dekel; Levenberg, Shulamit

    2015-08-01

    Abdominal wall reconstruction following extensive tissue loss is essential and can be achieved using autologous flaps. However, their use is limited due to their inadequate availability and due to post-operative donor site scarification. This work presents a step-by-step technique for fabrication of a vascularized muscle flap, to be applied in full-thickness abdominal wall defect reconstruction. Poly L-lactic acid/poly lactic-co-glycolic acid scaffolds, prepared using a salt leaching technique, were used as the supporting matrix in vitro for simultaneously seeded endothelial cells, fibroblasts and myoblasts. The cell-embedded graft was then implanted around femoral artery and vein vessels, which provided a central blood supply. Vascularization and perfusion were achieved by capillary sprouting from the main host vessel into the graft. A thick and vascularized tissue was formed within one week, and was then transferred as an autologous flap together with its main vessels, to a full-thickness abdominal wall defect. The flap remained viable after transfer and featured sufficient mechanical strength to support the abdominal viscera. Thus, this engineered muscle flap can be used as an alternative source for autologous flaps to reconstruct full-thickness abdominal wall defects.

  10. Bilobed flaps for nonhealing ulcer treatment.

    PubMed

    Yetkin, Haluk; Kanatli, Ulunay; Oztürk, Akif Muhtar; Ozalay, Metin

    2003-09-01

    Healing of round ulcers may be difficult particularly in the plantar area. Rigidity and thickness of the plantar skin do not allow fusiform excision and primary suturing. The bilobed flap is a simple reconstructive technique principally used to repair substantial defects in the facial region. The authors' experience with this local flap in the foot is presented with good short-term results. Between 1995 and 1998, five female and seven male neuropathic foot patients with round plantar ulcers were treated with bilobed flaps. The average age of the patients was 50 (range, 15-76). The average size of the ulcers was 1.6 cm (1-3.2 cm). Debridement and orthotic insoles were used at least for 3 months before considering bilobed flaps. Seven patients were diagnosed as type II diabetes mellitus, four patients had cerebral palsy, and another patient had meningomyelocele. The minimal follow-up period was 1 year (average, 19.5 months). The only complication was wound dehiscence at the lateral side of the heel in a type II diabetic. Subsequently, this complicated ulcer was managed with a sliding flap and skin graft without further problem. The study concluded that nonhealing foot ulcers can be effectively treated with a bilobed skin flap of healthy tissues rotated from nonweightbearing parts of the sole.

  11. The medial sural artery perforator free flap.

    PubMed

    Cavadas, P C; Sanz-Giménez-Rico, J R; Gutierrez-de la Cámara, A; Navarro-Monzonís, A; Soler-Nomdedeu, S; Martínez-Soriano, F

    2001-11-01

    The medial sural artery supplies the medial gastrocnemius muscle and sends perforating branches to the skin. The possible use of these musculocutaneous perforators as the source of a perforator-based free flap was investigated in cadavers. Ten legs were dissected, and the topography of significant perforating musculocutaneous vessels on both the medial and the lateral gastrocnemius muscles was recorded. A mean of 2.2 perforators (range, 1 to 4) was noted over the medial gastrocnemius muscle, whereas in only 20 percent of the specimens was a perforator of moderate size noted over the lateral gastrocnemius muscle. The perforating vessels from the medial sural artery clustered about 9 to 18 cm from the popliteal crease. When two perforators were present (the most frequent case), the perforators were located at a mean of 11.8 cm (range, 8.5 to 15 cm) and 17 cm (range, 15 to 19 cm) from the popliteal crease. A series of six successful clinical cases is reported, including five free flaps and one pedicled flap for ipsilateral lower-leg and foot reconstruction. The dissection is somewhat tedious, but the vascular pedicle can be considerably long and of suitable caliber. Donor-site morbidity was minimal because the muscle was not included in the flap. Although the present series is short, it seems that the medial sural artery perforator flap can be a useful flap for free and pedicled transfer in lower-limb reconstruction.

  12. Experimental comparison of bone revascularization by musculocutaneous and cutaneous flaps

    SciTech Connect

    Fisher, J.; Wood, M.B.

    1987-01-01

    Revascularization, one of the major components of bone healing, was examined in an experimental model. The radioactive microsphere technique demonstrated that after 4 weeks beneath a musculocutaneous flap, isolated bone segments had significant blood flow, whereas bone beneath a cutaneous flap did not. The muscle flap bone had a blood flow approximately half that of normal control bone. The muscle of the musculocutaneous flap had a blood flow three times that of the skin of the cutaneous flap. The bipedicle cutaneous flap used was designed to have a healthy blood supply, and at 4 weeks it had a blood flow twice that of control skin. Despite this, there was essentially no demonstrable blood flow in the cutaneous flap bone segments at 4 weeks. Only 3 of 17 bone segments underneath cutaneous flaps showed medullary vascularization, whereas 10 of 11 muscle flap bones did. All bone segments underneath muscle flaps showed osteoblasts and osteoclasts at 4 weeks; neither were seen in the cutaneous bone segments. The process of revascularization occurred through an intact cortex and penetrated into the cancellous bone. Because the bone segments were surrounded by an impervious barrier except for one cortical surface, the cellular activity seen is attributed to revascularization by the overlying flap. In this model, a muscle flap was superior to a cutaneous flap in revascularizing isolated bone segments at 4 weeks. This was documented by blood flow measured by the radioactive microsphere technique and by bone histology.

  13. The Internal Pudendal Artery Perforator Thigh Flap: A New Freestyle Pedicle Flap for the Ischial Region

    PubMed Central

    Goishi, Keiichi; Abe, Yoshiro; Takaku, Mitsuru; Seike, Takuya; Harada, Hiroshi; Nakanishi, Hideki

    2014-01-01

    Background: Recurrence and complication rates of pressure sores are highest in the ischial region, and other donor sites are needed for recurrent pressure sores. The potential of a new freestyle pedicle flap for ischial lesions, an internal pudendal artery perforator (iPap) thigh flap, was examined through anatomical and theoretical analyses and a case series using computed tomography angiography. Methods: The skin flap was designed in the thigh region based on an iPap. The skin perforators were marked with a Doppler probe. One patient underwent computed tomography angiography with fistulography to identify the damage to or effects on the pedicle vessels of the flap. Debridement of ischial lesions and flap elevation were performed in the jackknife position. Results: The iPap thigh flaps were performed in 5 patients, 4 with ischial pressure sores and 1 with calcinosis cutis of the ischial region. The width and length of the flaps ranged from 5 to 8 cm (mean, 6.6 cm) and 10 to 17 cm (mean, 12.6 cm), respectively. Three patients underwent partial osteotomy of the ischial bone. No complications, including flap necrosis or wound dehiscence of the donor and reconstructed sites, were observed. Conclusions: The perforator vessels of the internal pudendal artery are very close to the ischial tuberosity. Blood flow to the flap is reliable when careful debridement of the pressure sore is performed. The iPap thigh flap is a new option for soft-tissue defects in the ischial region, including ischial pressure sores. PMID:25289335

  14. Analysis of Flap Weight and Postoperative Complications Based on Flap Weight in Patients Undergoing Microsurgical Breast Reconstruction.

    PubMed

    Lam, Gretl; Weichman, Katie E; Reavey, Patrick L; Wilson, Stelios C; Levine, Jamie P; Saadeh, Pierre B; Allen, Robert J; Choi, Mihye; Karp, Nolan S; Thanik, Vishal D

    2017-03-01

    Background Higher body mass index (BMI) has been shown to increase postoperative complications in autologous breast reconstruction. However, the correlation with flap weight is unknown. Here, we explore the relationship of flap weights and complication rates in patients undergoing microvascular breast reconstruction. Methods Retrospective chart review identified all patients undergoing microvascular breast reconstruction with abdominally based flaps at a single institution between November 2007 and April 2013. Breasts with documented flap weight and 1-year follow-up were included. Patients undergoing stacked deep inferior epigastric perforator flaps were excluded. Breasts were divided into quartiles based on flap weight and examined by demographics, surgical characteristics, complications, and revisions. Results A total of 130 patients undergoing 225 flaps were identified. Patients had a mean age of 50.4 years, mean BMI of 27.1 kg/m(2), and mean flap weight of 638.4 g (range: 70-1640 g). Flap weight and BMI were directly correlated. Flaps were divided into weight-based quartiles: first (70-396 g), second (397-615 g), third (616-870 g), and fourth (871-1640 g). There were no associations between flap weight and incidences of venous thrombosis, arterial thrombosis, hematoma, flap loss, fat necrosis, or donor site hernia. However, increased flap weight was associated with increased rate of donor site wound healing problems in both univariate and multivariate analysis. Conclusions Increased flap weight is not associated with added flap complications among patients undergoing microvascular breast reconstruction, however, patients with flaps of 667.5 g or more are more likely to have donor site healing problems. The success and evidence contrary to previous studies may be attributed to surgeon intraoperative flap choice.

  15. Microsurgical free flap reconstructions of the head and neck region: Shanghai experience of 34 years and 4640 flaps.

    PubMed

    Zhang, C; Sun, J; Zhu, H; Xu, L; Ji, T; He, Y; Yang, W; Hu, Y; Yang, X; Zhang, Z

    2015-06-01

    This study represents the surgical experience of 4481 microvascular free flap cases performed at the authors' institution in China, between 1979 and 2013. Four thousand four hundred and eighty-one patients underwent reconstruction with 4640 flaps: 56% radial forearm flaps, 8% iliac crest flaps, 13% fibula flaps, 10% anterolateral thigh flaps, and other flaps. In the overwhelming majority of cases, the flap transfer was required following tumour resection (97.5%). Three hundred and twenty minor complications (6.9%) occurred. One hundred and eighteen major complications (2.5%) were encountered: 114 cases of failure (2.4%) and four deaths. Among the 118 cases with major complications, 26 - 22.0% - had received radiotherapy; this proportion was higher than the 6.9% in the minor complications group and 8.1% in the non-intervention group. Venous thrombosis was the most common complication at the recipient site and was the main cause of flap failure. When a compromised flap is identified, surgical re-exploration should not be delayed. This study confirms that free flaps are reliable in achieving successful reconstruction in the head and neck region; however this technique requires extensive clinical experience. Owing to the large number of flap options, microsurgeons should always pay attention to the details of the different surgical defects and choose the most appropriate flap.

  16. Analytical study of vortex flaps on highly swept delta wings

    NASA Technical Reports Server (NTRS)

    Frink, N. T.

    1982-01-01

    This paper highlights some current results from ongoing analytical studies of vortex flaps on highly swept delta wings. A brief discussion of the vortex flow analysis tools is given along with comparisons of the theories to vortex flap force and pressure data. Theoretical trends in surface pressure distribution for both angle-of-attack variation and flap deflection are correctly predicted by Free Vortex Sheet theory. Also shown are some interesting calculations for attached-flow and vortex-flow flap hinge moments that indicate flaps utilizing vortex flow may generate less hinge moment than attached flow flaps. Finally, trailing-edge flap effects on leading-edge flap thrust potential are investigated and theory-experiment comparisons made.

  17. Free flap monitoring in plastic and reconstructive surgery.

    PubMed

    Pickett, John A; Thorniley, Maureen S; Carver, Nigel; Jones, Deric P

    2003-01-01

    Free flaps are regularly used in plastic and reconstructive surgery but have a significant failure rate due to vessel thrombosis in the re-established arterial or venous circulation. A monitor of flap perfusion and oxygenation would allow the early detection of progressing flap ischaemia, hastening the required intervention and maximising the chances of salvaging the flap. A dual wavelength spectrophotometer has been designed and constructed which can monitor haemodynamic events in flaps during surgery and postoperatively. Eleven patients undergoing free flap surgery were studied. Measurements were made during surgery before division of the vessels and during and after microvascular anastomosis. Significant changes in all parameters were observed on reperfusion of the flaps after anastomosis or tourniquet ischaemia. Abnormal reperfusion in one flap and subsequent ischaemic events in two others were identified.

  18. Experimental and Numerical investigations of flapping flight

    NASA Astrophysics Data System (ADS)

    Krithivasan, Siddharth; Ansumali, Santosh; Kr, Sreenivas; Emu, Jncasr Collaboration

    2012-11-01

    Insects have been observed to produce higher lift than predicted by conventional steady-aerodynamics using a combination of unsteady aerodynamic mechanisms. The wing kinematics and the flow fields produced during flapping flight is essentially 3D. Recently, in our group it has been shown, using flow visualization and 2D simulations, that the asymmetric flapping where, down-stroke is faster than the upstroke, can produce sustained lift. Also by introducing controlled wing flexibility, one can increase the magnitude of the lift. In order to verify these predictions quantitatively we are measuring forces produced by a mechanical flapper using a force-balance. Results of this study will be presented that includes the forces measured in symmetric and asymmetric flapping at different flapping frequencies. Similar understanding of various wing-kinematics during a forward flight can be achieved by doing transient, 3D simulations. A fast, accurate and simple 3D scheme which is capable of dealing with moving boundaries using Lattice Boltzmann has been developed for this purpose. Benchmarking of this scheme has been done for a forward flapping of the wing with elliptical cross-section. The results on the benchmarking and other preliminary results will be presented in the conference.

  19. Hardware Removal after Osseous Free Flap Reconstruction

    PubMed Central

    Day, Kristine E.; Desmond, Renee; Magnuson, J. Scott; Carroll, William R.; Rosenthal, Eben L.

    2015-01-01

    Objective Identifying risk factors for hardware removal in patients undergoing mandibular reconstruction with vascularized osseous free flaps remains a challenge. The purpose of this study is to identify potential risk factors, including osteocutaneous radial forearm versus fibular flap, for need for removal and to describe the fate of implanted hardware. Study Design Case series with chart review. Setting Academic tertiary care medical center. Subjects and Methods Two hundred thirteen patients undergoing 227 vascularized osseous mandibular reconstructions between the years 2004 and 2012. Data were compiled through a manual chart review, and patients incurring hardware removals were identified. Results Thirty-four of 213 evaluable vascularized osseous free flaps (16%) underwent surgical removal of hardware. The average length of time to removal was 16.2 months (median 10 months), with the majority of removals occurring within the first year. Osteocutaneous radial forearm free flaps (OCRFFF) incurred a slightly higher percentage of hardware removals (9.9%) compared to fibula flaps (6.1%). Partial removal was performed in 8 of 34 cases, and approximately 38% of these required additional surgery for removal. Conclusion Hardware removal was associated with continued tobacco use after mandibular reconstruction (P = .03). Removal of the supporting hardware most commonly occurs from infection or exposure in the first year. In the majority of cases the bone is well healed and the problem resolves with removal. PMID:24201061

  20. Posttraumatic eyebrow reconstruction with hair-bearing temporoparietal fascia flap

    PubMed Central

    Denadai, Rafael; Raposo-Amaral, Cassio Eduardo; Marques, Frederico Figueiredo; Raposo-Amaral, Cesar Augusto

    2015-01-01

    The temporoparietal fascia flap has been extensively used in craniofacial reconstructions. However, its use for eyebrow reconstruction has been sporadically reported. We describe a successfully repaired hair-bearing temporoparietal fascia flap after traumatic avulsion of eyebrow. Temporoparietal fascia flap is a versatile tool and should be considered as a therapeutic option by all plastic surgeons. PMID:25993077

  1. Crossed pectoralis major myocutaneous flap for recurrent oral cavity cancers

    PubMed Central

    Pancholi, Mayank; Sharma, Sanjay; Desai, Sanjay M.; Agrawal, Deepak

    2016-01-01

    Background: Oral cavity cancers are fairly common and have propensity to recur locally. Since Pectoralis Major Myocutaneous (PMMC) flap is the most widely used first flap for reconstruction, it is exhausted at the earliest and recurrence poses a formidable challenge for reconstructive surgeon. Present study evaluated the feasibility of contralateral Pectoralis Major Myocutaneous Flap for reconstruction after resection of recurrent tumour. Methods: This was a study of the patients presenting with recurrent oral cavity cancer after exhausted ipsilateral Pectoralis Major Myocutaneous Flap (PMMC) in whom we used contralateral Pectoralis Major Myocutaneous Flap (Crossed PMMC Flap) for reconstruction between October 2013 to June 2016. Results: Five patients with recurrence underwent reconstruction with contralateral Pectoralis Major Myocutaneous Flap. In all the flap was successfully used to reconstruct defects involving the entire buccal mucosa and in one patient the flap could be used to reconstruct full thickness resection defect(crossed bipedal PMMC Flap) with ease. Conclusion: Crossed Pectoralis Major Myocutaneous Flap can be used safely and reliably for reconstruction of the buccal mucosal defect and in selected patients even for full thickness cheek defect as folded bipaddle Pectoralis Major Myocutaneous Flap.

  2. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  3. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 14 Aeronautics and Space 1 2014-01-01 2014-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  4. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 14 Aeronautics and Space 1 2013-01-01 2013-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  5. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 14 Aeronautics and Space 1 2012-01-01 2012-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  6. 14 CFR 23.699 - Wing flap position indicator.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Wing flap position indicator. 23.699 Section 23.699 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION... Construction Control Systems § 23.699 Wing flap position indicator. There must be a wing flap...

  7. Free flap rescue using an extracorporeal perfusion device.

    PubMed

    Fichter, Andreas M; Ritschl, Lucas M; Rau, Andrea; Schwarzer, Claudia; von Bomhard, Achim; Wagenpfeil, Stefan; Wolff, Klaus-Dietrich; Mücke, Thomas

    2016-12-01

    The warm ischaemia time of microvascular free flaps is limited. Incalculable events, such as lack of adequate recipient vessels or intraoperative medical emergencies, can lead to prolonged ischaemia and potentially to flap loss. In this study, critically perfused ischaemic or congested flaps were temporarily perfused with an extracorporeal perfusion system until anastomosis could be commenced. Temporary extracorporeal perfusion was performed in 8 radial forearm flaps for 147 ± 52 (range 77-237) minutes. Flap perfusion was assessed using Indocyanine Green fluorescence angiography and combined laser Doppler flowmetry and remission spectroscopy. Results were compared with those of 30 patients who underwent conventional reconstruction with radial forearm flaps. Flap survival, flap microcirculation, postoperative complications, and hospital stay did not differ between groups. We report successful free flap transfer after short-term extracorporeal perfusion for up to 4 h in 8 patient cases. Temporary extracorporeal free flap perfusion reduces the warm ischaemia time in emergency situations and can help to prevent flap failure in critically perfused or congested flaps. The trial is registered with ClinicalTrials.gov, number NCT02449525.

  8. New developments in blown flap noise technology

    NASA Technical Reports Server (NTRS)

    Gibson, J. S.

    1976-01-01

    The noise technology relating to blown-flap systems is reviewed. There are three general sources of noise: turbomachinery, airframe, and the interaction noise of the jet blowing on the flaps. The latter noise-source area is the most critical and the main subject dicussed. Characteristics of lower surface blown and upper surface blown systems are described, including noise spectra, directivity, jet velocity characteristics, aircraft geometric variation effects, and aircraft forward speed effects. Noise reduction concepts are described, including slowing down the jet flow field by devices and engine cycle modifications, structural geometry and shielding modifications, local flow field modifications of the passive and active type, and the absorption of noise. It is concluded that, while there has been considerable progress in the past several years, low noise characteristics in blown flap aircraft must be largely built in by better application of low noise principles during the design.

  9. Numerical linearized MHD model of flapping oscillations

    NASA Astrophysics Data System (ADS)

    Korovinskiy, D. B.; Ivanov, I. B.; Semenov, V. S.; Erkaev, N. V.; Kiehas, S. A.

    2016-06-01

    Kink-like magnetotail flapping oscillations in a Harris-like current sheet with earthward growing normal magnetic field component Bz are studied by means of time-dependent 2D linearized MHD numerical simulations. The dispersion relation and two-dimensional eigenfunctions are obtained. The results are compared with analytical estimates of the double-gradient model, which are found to be reliable for configurations with small Bz up to values ˜ 0.05 of the lobe magnetic field. Coupled with previous results, present simulations confirm that the earthward/tailward growth direction of the Bz component acts as a switch between stable/unstable regimes of the flapping mode, while the mode dispersion curve is the same in both cases. It is confirmed that flapping oscillations may be triggered by a simple Gaussian initial perturbation of the Vz velocity.

  10. Collective Flow Enhancement by Tandem Flapping Wings.

    PubMed

    Gravish, Nick; Peters, Jacob M; Combes, Stacey A; Wood, Robert J

    2015-10-30

    We examine the fluid-mechanical interactions that occur between arrays of flapping wings when operating in close proximity at a moderate Reynolds number (Re≈100-1000). Pairs of flapping wings are oscillated sinusoidally at frequency f, amplitude θ_{M}, phase offset ϕ, and wing separation distance D^{*}, and outflow speed v^{*} is measured. At a fixed separation distance, v^{*} is sensitive to both f and ϕ, and we observe both constructive and destructive interference in airspeed. v^{*} is maximized at an optimum phase offset, ϕ_{max}, which varies with wing separation distance, D^{*}. We propose a model of collective flow interactions between flapping wings based on vortex advection, which reproduces our experimental data.

  11. Comparison of a new flap design with the routinely used triangular flap design in third molar surgery.

    PubMed

    Yolcu, Ü; Acar, A H

    2015-11-01

    The aim of this study is to introduce a new flap design in the surgical removal of impacted mandibular third molars - a lingually based triangular flap - and to compare this flap design with the routinely used triangular flap. This randomized, prospective, split-mouth study involved 22 patients with impacted bilateral mandibular third molars that were symmetrically positioned, mesially angulated, and retained in bone. The impacted teeth were removed in two sessions, using two different flap designs: the new alternative flap and the traditional triangular flap. Postoperative complications (pain, swelling, trismus, alveolar osteitis, and wound dehiscence) were recorded on days 2, 7, 14, and 21. The data obtained were analysed using the χ(2) test, the Mann-Whitney U-test, and Pearson's correlation. In terms of the severity of postoperative facial swelling and trismus, there were no statistically significant differences between the flap designs (P>0.05). The alternative flap exhibited higher pain scores at 12h post-surgery (P<0.05). In addition, the alternative flap group exhibited less wound dehiscence, although this was not statistically significant. Moreover, all wound dehiscence in this group occurred on sound bone. In conclusion, these results show that this new flap design is preferable to the routinely used flap for impacted third molar surgery.

  12. Flap Edge Aeroacoustic Measurements and Predictions

    NASA Technical Reports Server (NTRS)

    Brooks, Thomas F.; Humphreys, William M., Jr.

    2000-01-01

    An aeroacoustic model test has been conducted to investigate the mechanisms of sound generation on high-lift wing configurations. This paper presents an analysis of flap side-edge noise, which is often the most dominant source. A model of a main element wing section with a half-span flap was tested at low speeds of up to a Mach number of 0.17, corresponding to a wing chord Reynolds number of approximately 1.7 million. Results are presented for flat (or blunt), flanged, and round flap-edge geometries, with and without boundary-layer tripping, deployed at both moderate and high flap angles. The acoustic database is obtained from a Small Aperture Directional Array (SADA) of microphones, which was constructed to electronically steer to different regions of the model and to obtain farfield noise spectra and directivity from these regions. The basic flap-edge aerodynamics is established by static surface pressure data, as well as by Computational Fluid Dynamics (CFD) calculations and simplified edge flow analyses. Distributions of unsteady pressure sensors over the flap allow the noise source regions to be defined and quantified via cross-spectral diagnostics using the SADA output. It is found that shear layer instability and related pressure scatter is the primary noise mechanism. For the flat edge flap, two noise prediction methods based on unsteady-surface-pressure measurements are evaluated and compared to measured noise. One is a new causality spectral approach developed here. The other is a new application of an edge-noise scatter prediction method. The good comparisons for both approaches suggest that much of the physics is captured by the prediction models. Areas of disagreement appear to reveal when the assumed edge noise mechanism does not fully define, the noise production. For the different edge conditions, extensive spectra and directivity are presented. Significantly, for each edge configuration, the spectra for different flow speeds, flap angles, and

  13. Airplane wing leading edge variable camber flap

    NASA Technical Reports Server (NTRS)

    Cole, J. B.

    1980-01-01

    The invention and design of an aerodynamic high lift device which provided a solution to an aircraft performance problem are described. The performance problem of converting a high speed cruise airfoil into a low speed aerodynamic shape that would provide landing and take-off characteristics superior to those available with contemporary high lift devices are addressed. The need for an improved wing leading edge device that would complement the high lift performance of a triple slotted trailing edge flap is examined. The mechanical and structural aspects of the variable camber flap are discussed and the aerodynamic performance aspects only as they relate to the invention and design of the device are presented.

  14. Salvage for pectoralis major myocutaneous flap failure in head and neck reconstruction by microvascular flap.

    PubMed

    Tang, Chen-Ling; Wu, Yi-Chia; Lai, Ching-Hung; Lai, Chung-Sheng; Lin, Chih-Lung; Lin, Sin-Daw; Chang, Kao-Ping

    2012-10-01

    The pectoralis major myocutaneous pedicled flap (PMMPF) - the "workhorse" for head and neck reconstruction - is associated with a high incidence of complications in certain cases. This study presents free tissue transfer as an alternative salvage technique after PMMPF failure in head and neck reconstruction. It includes seven consecutive patients who underwent free tissue salvage after PMMPF failure in head and neck reconstruction from January 2008 to September 2010 at Kaohsiung Medical University Hospital, Taiwan. Four vertical rectus abdominis myocutaneous (VRAM) flaps were applied for tongue and mouth floor defects, while three anterolateral thigh (ALT) flaps were used for mouth floor, buccal, and cheek defects. All flaps survived uneventfully, and normal oral feeding was achieved without major complications. Free tissue transfer has several advantages and can be successfully employed in head and neck reconstruction, and it is also a reliable salvage procedure after PMMPF failure in such cases.

  15. Choice of Flap Affects Fistula Rate after Salvage Laryngopharyngectomy

    PubMed Central

    Kao, Huang-Kai; Abdelrahman, Mohamed; Chang, Kai-Ping; Wu, Chao-Min; Hung, Shao-Yu; Shyu, Victor Bong-Hang

    2015-01-01

    Due to the significant morbidity and mortality associated with pharyngocutaneous fistula in pharyngoesophageal reconstruction following cancer resection, the purpose of this retrospective study is to examine the selection of tubed skin flaps that impact anastomotic integrity. The flaps evaluated included radial forearm flap versus anterolateral thigh flap, and fasciocutaneous anterolateral thigh flap versus chimeric anterolateral thigh flap. The outcome of interest is the incidence of pharyngocutaneous fistula. The radial forearm group had a significantly higher rate of fistula than the anterolateral thigh group (56.6% vs. 30.2%, p = 0.03). No significant difference in the incidence of fistula was demonstrated between fasciocutaneous and chimeric anterolateral thigh flap (36.8% vs. 25%, p = 0.51). The anastomotic integrity in pharyngoesopharyngeal reconstruction is affected by choice of skin flaps. Anterolateral thigh flap appears to be a viable option for pharyngoesophageal reconstruction. The more technical demand of the anterolateral thigh flap must be weighed against an easily harvested radial forearm flap. PMID:25776941

  16. Tunnelled tensor fascia lata flap for complex abdominal wall reconstruction

    PubMed Central

    Wang, Frederick; Buonocore, Samuel; Narayan, Deepak

    2011-01-01

    This study describes the treatment of two patients with recurrent, infected abdominal wall defects using bilateral delayed and tunnelled pedicled tensor fascia lata (TFL) myofascial flaps. TFL flaps were elevated and delayed for 4 weeks in both cases. In the second case, Parietex Composite mesh was positioned underneath the TFL flap and allowed to incorporate. After a delay of 4 weeks, the flaps were harvested and tunnelled subcutaneously to repair the abdominal wall defect. Both patients have stable repairs but had donor site seromas requiring drainage. Cadaver dissection was also performed to identify structures related to TFL flap harvest. We identified a variant of lateral femoral cutaneous nerve that traversed the TFL flap, necessitating meticulous dissection during surgery. In summary, we describe a new technique of incorporating mesh into the TFL prior to flap harvest for reconstruction of complex abdominal wall. PMID:22707661

  17. Aerodynamic characteristics of NACA 4412 airfoil sction with flap

    NASA Astrophysics Data System (ADS)

    Ockfen, Alex E.; Matveev, Konstantin I.

    2009-09-01

    Wing-in-Ground vehicles and aerodynamically assisted boats take advantage of increased lift and reduced drag of wing sections in the ground proximity. At relatively low speeds or heavy payloads of these craft, a flap at the wing trailing-ground-effect flow id numerically investigated in this study. The computational method consists of a steady-state, incompressible, finite volume method utilizing the Spalart-Allmaras turbulence model. Grid generation and solution of the Navier-Stokes equations are completed flow with a flap, as well as ground-effect motion without a flap. Aerodynamic forces are plain flap. Changes in the flow introduced with the flap addition are also discussed. Overall, the use of a flap on wings with small attack angles is found to be beneficial for small flap deflections up to 5% of the chord, where the contribution of lift augmentation exceeds the drag increase, yielding an augmented lift-to-drag ratio

  18. Effect of Systemic Antioxidant Allopurinol Therapy on Skin Flap Survival

    PubMed Central

    Rasti Ardakani, Mehdi; Al-Dam, Ahmed; Rashad, Ashkan; Shayesteh Moghadam, Ali

    2017-01-01

    BACKGROUND It has been reported that systemic administration of allopurinol improves cell survival. This study was aimed to evaluate effects of allopurinol on skin flaps in dogs. METHODS Twenty dogs underwent one skin flap surgery with a 2-week interval. The first procedure was performed according to the standard protocols. The second phase was started by a 1-week pretreatment with allopurinol. Length of the necrotic zone was measured and recorded daily. At each phase, flaps were removed and sent for histopathological study after 1 week observation. RESULTS Mean length of the necrotic zone in allopurinol treated skin flaps has been significantly less than normal flaps over all 7 days of observation (p<0.0001). Histopathology study showed less inflammation and more normal tissue structure in the allopurinol treated skin flaps. CONCLUSION It was demonstrated that systemic administration of allopurinol significantly improved skin flap survival. PMID:28289614

  19. The value of postoperative anticoagulants to improve flap survival in the free radial forearm flap

    PubMed Central

    Swartz, Justin E.; Aarts, Mark C.J.; Swart, Karin M.A.; Disa, Joseph J.; Gerressen, Marcus; Kuo, Yur-Ren; Wax, Mark K.; Grolman, Wilko; Braunius, Weibel W

    2016-01-01

    Background Free radial forearm flap (FRFF) reconstruction is a valuable technique in head and neck surgery, that allows closure of large defects while striving to maintain functionality. Anticoagulative drugs are often administered to improve flap survival, although evidence regarding effectiveness is lacking. Objective of review To investigate the effectiveness of postoperative anticoagulants to improve survival of the FRFF in head and neck reconstruction. Type of review Systematic review and multicenter, individual patient data meta-analysis. Search strategy MEDLINE, EMBASE, Web of Science and CINAHL were searched for synonyms of ‘anticoagulants’ and ‘free flap reconstruction’. Evaluation method Studies were critically appraised for directness of evidence and risk of bias. Authors of the highest quality publications were invited to submit their original data for meta-analysis. Results Five studies were of adequate quality and data from four studies (80%) were available for meta-analysis, describing 759 FRFF procedures. Anticoagulants used were: aspirin (12%), low-molecular weight dextran (18.3%), unfractioned heparin (28.1%), low-molecular weight heparin (49%) and prostaglandin-E1 (2.1%). Thirty-one percent did not receive anticoagulants. Flap failure occurred in 40 of 759 patients (5.3%) On univariate analysis, use of unfractioned heparin was associated with a higher rate of flap failure. However, these regimens were often administered to patients who had revision surgery of the anastomosis. In multivariate logistic regression analysis, anticoagulant use was not associated with improved flap survival or flap-related complications. Conclusions The studied anticoagulative drugs did not improve FRFF survival or lower the rate of flap-related complications. In addition some anticoagulants may cause systemic complications. PMID:25823832

  20. To flap or not to flap: a discussion between a fish and a jellyfish

    NASA Astrophysics Data System (ADS)

    Martin, Nathan; Roh, Chris; Idrees, Suhail; Gharib, Morteza

    2016-11-01

    Fish and jellyfish are known to swim by flapping and by periodically contracting respectively, but which is the more effective propulsion mechanism? In an attempt to answer this question, an experimental comparison is made between simplified versions of these motions to determine which generates the greatest thrust for the least power. The flapping motion is approximated by pitching plates while periodic contractions are approximated by clapping plates. A machine is constructed to operate in either a flapping or a clapping mode between Reynolds numbers 1,880 and 11,260 based on the average plate tip velocity and span. The effect of the total sweep angle, total sweep time, plate flexibility, and duty cycle are investigated. The average thrust generated and power required per cycle are compared between the two modes when their total sweep angle and total sweep time are identical. In general, operating in the clapping mode required significantly more power to generate a similar thrust compared to the flapping mode. However, modifying the duty cycle for clapping caused the effectiveness to approach that of flapping with an unmodified duty cycle. These results suggest that flapping is the more effective propulsion mechanism within the range of Reynolds numbers tested. This work was supported by the Charyk Bio-inspired Laboratory at the California Institute of Technology, the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1144469, and the Summer Undergraduate Research Fellowships program.

  1. Enhanced Correlation of SMART Active Flap Rotor Loads

    NASA Technical Reports Server (NTRS)

    Kottapalli, Sesi

    2011-01-01

    This is a follow-on study to a 2010 correlation effort. Measured data from the SMART rotor test in the NASA Ames 40- by 80- Foot Wind Tunnel are compared with CAMRAD II calculations. As background, during the wind tunnel test, unexpectedly high inboard loads were encountered, and it was hypothesized at that time that due to changes in the flexbeams over the years, the flexbeam properties used in the analysis needed updating. Boeing Mesa, recently updated these properties. This correlation study uses the updated flexbeam properties. Compared to earlier studies, the following two enhancements are implemented: i) the inboard loads (pitchcase and flexbeam loads) correlation is included for the first time (reliable prediction of the inboard loads is a prerequisite for any future anticipated flight-testing); ii) the number of blade modes is increased to better capture the flap dynamics and the pitchcase-flexbeam dynamics. Also, aerodynamically, both the rolled-up wake model and the more complex, multiple trailer wake model are used, with the latter slightly improving the blade chordwise moment correlation. This sensitivity to the wake model indicates that CFD is needed. Three high-speed experimental cases, one uncontrolled free flap case and two commanded flap cases, are considered. The two commanded flap cases include a 2o flap deflection at 5P case and a 0o flap deflection case. For the free flap case, selected modifications to the HH-06 section flap airfoil pitching moment table are implemented. For the commanded 2o flap case, the experimental flap variation is approximately matched by increasing the analytical flap hinge stiffness. This increased flap hinge stiffness is retained for the commanded 0o flap case also, which is treated as a free flap case, but with larger flap hinge stiffness. The change in the mid-span and outboard loads correlation due to the updating of the flexbeam properties is not significant. Increasing the number of blade modes results in an

  2. Flapping wing aerodynamics: from insects to vertebrates.

    PubMed

    Chin, Diana D; Lentink, David

    2016-04-01

    More than a million insects and approximately 11,000 vertebrates utilize flapping wings to fly. However, flapping flight has only been studied in a few of these species, so many challenges remain in understanding this form of locomotion. Five key aerodynamic mechanisms have been identified for insect flight. Among these is the leading edge vortex, which is a convergent solution to avoid stall for insects, bats and birds. The roles of the other mechanisms - added mass, clap and fling, rotational circulation and wing-wake interactions - have not yet been thoroughly studied in the context of vertebrate flight. Further challenges to understanding bat and bird flight are posed by the complex, dynamic wing morphologies of these species and the more turbulent airflow generated by their wings compared with that observed during insect flight. Nevertheless, three dimensionless numbers that combine key flow, morphological and kinematic parameters - the Reynolds number, Rossby number and advance ratio - govern flapping wing aerodynamics for both insects and vertebrates. These numbers can thus be used to organize an integrative framework for studying and comparing animal flapping flight. Here, we provide a roadmap for developing such a framework, highlighting the aerodynamic mechanisms that remain to be quantified and compared across species. Ultimately, incorporating complex flight maneuvers, environmental effects and developmental stages into this framework will also be essential to advancing our understanding of the biomechanics, movement ecology and evolution of animal flight.

  3. Propulsion of a flapping and oscillating airfoil

    NASA Technical Reports Server (NTRS)

    Garrick, I E

    1937-01-01

    Formulas are given for the propelling or drag force experience in a uniform air stream by an airfoil or an airfoil-aileron combination, oscillating in any of three degrees of freedom; vertical flapping, torsional oscillations about a fixed axis parallel to the span, and angular oscillations of the aileron about a hinge.

  4. Free Surface and Flapping Foil Interactions

    NASA Astrophysics Data System (ADS)

    Ananthakrishnan, Palaniswamy

    2014-11-01

    Flapping foils for station-keeping of a near-surface body in a current is analyzed using a finite-difference method based on boundary-fitted coordinates. The foils are hinge-connected to the aft of the body and subject to pitch oscillation. Results are obtained for a range of Strouhal number, Froude number, unsteady frequency parameter τ, Reynolds number and the depth of foil submergence. Results show that at low Strouhal number (St < 0 . 1) and sub-critical unsteady parameter τ < 0 . 25 , the flapping generates drag instead of thrust. At high Strouhal number and super-critical value of the unsteady parameter (τ > 0 . 25) flapping generates high thrust with low efficiency. Thrust and efficiency are found to decrease with decreasing submergence depth of the foil. At the critical τ = 0 . 25 and shallow submergence of the foil, the standing wave generated above the foil continues to grow until breaking; both the thrust and efficiency of the foil are reduced at the critical τ. The necessary conditions for optimal thrust generation by a flapping foil underneath the free surface are found to be (i) Strouhal number in the range from 0.25 to 0.35, (ii) unsteady parameter τ > 0 . 25 and (iii) the maximum angle of attack less than 15° for the flat-plate foil. Supported by the US Office of Naval Research through the Naval Engineering Education Center (NEEC) Consortium of the University of Michigan, Ann Arbor.

  5. Aerohydrodynamics of flapping-wing propulsors

    NASA Astrophysics Data System (ADS)

    Rozhdestvensky, Kirill V.; Ryzhov, Vladimir A.

    2003-11-01

    It is the objective of this survey to review research and development results of flapping-wing propulsors and of vehicles equipped with them. Given the complex and multi-disciplinary character of the problem, a wide range of questions is considered in order to provide a general idea of the state-of-the-art. The main attention is directed at the aerohydrodynamics of flapping-wing propulsors. The major relevant mathematical models and the corresponding numerical results are presented together with the experimental data obtained up to the present time. Also, the physical and the design factors are discussed, which affect the aerohydrodynamic characteristics of flapping wings and that therefore have to be accounted for in the modern mathematical models. Experimental data and numerical modeling results are compared to determine domains of validity of the latter for the aerohydrodynamic design of full-scale air and marine vehicles. Also, existing engineering solutions for vehicles with flapping-wing propulsors are presented and prospective directions for future investigations are outlined.

  6. Comparison of the Results of Early Flap Coverage with Late Flap Coverage in High-Voltage Electrical Injury.

    PubMed

    Karimi, Hamid; Akhoondinasab, Mohammad-Reza; Kazem-Zadeh, Jafar; Dayani, Ahmad-Reza

    Patients with high-voltage electrical injuries had very high rates of infection, morbidity, and limb amputation. The results of early and late flap coverage in these patients were prospectively compared. The patients were divided into two groups, early flap group (≤3 weeks) and late flap group (>3 weeks), according to the length of time from injury to wound coverage with flap. Age, sex, demographic data, time taken for flap coverage, time taken for pedicle division, time taken to discharge, wound infection, range of motion in joints, amputation, mortality, and outcome were gathered in a special questionnaire. This study included 55 patients, 31 within the early flap group and 24 within the late flap group. Of the 55 patients, 94.6% were male; mean (SD) of age was 29.04 (10.11) and of TBSA was 13.8 (10.07). Length of stay was significantly longer in the late flap group. The rates of infection and amputation were lower in the early flap group. There was no correlation between the type and the number of flaps and amputations. Early flap repair reduces the length of stay by 56%, rate of amputation by 54%, and also 86.1% in the rate of infection in the burn site.

  7. Outcome and complications of 540 microvascular free flaps: the Hamburg experience.

    PubMed

    Pohlenz, Philipp; Blessmann, Marco; Blake, Felix; Li, Lei; Schmelzle, Rainer; Heiland, Max

    2007-03-01

    The aim of this study was to retrospectively analyze surgical outcome and complications of 540 free flap procedures performed at the Department of Oral and Maxillofacial Surgery of the University Medical Center Hamburg-Eppendorf during 1987-2005. A total of 532 patients were reconstructed with 540 flaps: 32% were latissimus dorsi flaps, 23% were radial forearm flaps, 21% were iliac crest flaps, 10% were fibula flaps, 6% were jejunal flaps, and 8% were other flaps. Thrombosis of one of the vessels and hematoma were the most frequent causes of failure in microvascular free tissue transfer. A total free flap failure occurred in 34 (6.2%) and a partial flap failure in 42 (7.7%) patients. The most reliable flap in regard to survival was the radial forearm flap. The present study confirms that free flaps are extremely reliable in achieving successful reconstruction of the head and neck.

  8. A Miniature Controllable Flapping Wing Robot

    NASA Astrophysics Data System (ADS)

    Arabagi, Veaceslav Gheorghe

    The agility and miniature size of nature's flapping wing fliers has long baffled researchers, inspiring biological studies, aerodynamic simulations, and attempts to engineer their robotic replicas. Flapping wing flight is characterized by complex reciprocating wing kinematics, transient aerodynamic effects, and very small body lengths. These characteristics render robotic flapping wing aerial vehicles ideal for surveillance and defense applications, search and rescue missions, and environment monitoring, where their ability to hover and high maneuverability is immensely beneficial. One of the many difficulties in creating flapping wing based miniature robotic aerial vehicles lies in generating a proper wing trajectory that would result in sufficient lift forces for hovering and maneuvering. Since design of a flapping wing system is a balance between overall weight and the number of actuated inputs, we take the approach of having minimal controlled inputs, allowing passive behavior wherever possible. Hence, we propose a completely passive wing pitch reversal design that relies on wing inertial dynamics, an elastic energy storage mechanism, and low Reynolds number aerodynamic effects. Theoretical models, compiling previous research on piezoelectric actuators, four-bar transmissions, and aerodynamics effects, are developed and used as basis for a complete numerical simulation. Limitations of the model are discussed in comparison to experimental results obtained from a working prototype of the proposed passive pitch reversal flapping wing mechanism. Given that the mechanism is under-actuated, methods to control lift force generation by actively varying system parameters are proposed, discussed, and tested experimentally. A dual wing aerial platform is developed based on the passive pitch reversal wing concept. Design considerations are presented, favoring controllability and structural rigidity of the final platform. Finite element analysis and experimental

  9. Wind-tunnel Investigation of Two Airfoils with 25-percent-chord Gwinn and Plain Flaps

    NASA Technical Reports Server (NTRS)

    Ames, Milton B , Jr

    1940-01-01

    Aerodynamic force tests of an NACA 23018 airfoil with a Gwinn flap having a chord 25 percent of the overall chord and of an NACA 23015 airfoil with a plain flap having a 25-percent chord were conducted to determine the relative merits of the Gwinn and the plain flaps. The tests indicated that, based on speed-range ratios, the plain flap was more effective than the Gwinn flap. At small flap deflections, the plain flap had lower drag coefficients at lift-coefficient values less than 0.70. For lift coefficients greater than 0.70, however, the Gwinn flap at all downward flap deflections had the lower drag coefficients.

  10. [Vestibularly displaced flap with bone augmentation].

    PubMed

    Bakalian, V L

    2009-01-01

    The aim of this study is to achieve esthetic gingival contours with the help of less traumatic mucogingival surgeries. 9 Patients were operated with horizontal deficiencies in 9 edentulous sites, planned to be restored with fixed partial dentures. In all cases there was lack of keratinized tissues. Temporary bridges were fabricated to all patients. Before surgery the bridges were removed and the abutment teeth were additionally cleaned with ultrasonic device. A horizontal incision was made from lingual (palatal) side between the abutment teeth, which was connected with two vertical releasing incisions to the mucogingival junction from the vestibular side. The horizontal incision was made on a distance 6-10 mm from the crest of the alveolar ridge. A partial thickness flap in the beginning 3-5 mm, then a full thickness flap up to the mucogingival junction, then a partial thickness flap was made. The flap was mobilized and displaced vestibularly. In the apical part the cortical bone was perforated, graft material was put and the flap was sutured. In all 9 cases the horizontal defect was partially or fully eliminated. The width of the keratinized tissues was also augmented in all cases. The postoperative healing was without complications, discomfort and painless. The donor sites also healed without complications. The application of Solcoseryl Dental Adhesive Paste 3 times a day for 7-10 days helped for painless healing of the donor site. The offered method of soft tissue and bone augmentation is effective in the treatment of horizontal defects of edentulous alveolar ridges of not big sizes. It makes possible to achieve esthetic results without traumatizing an additional donor-site.

  11. An ameliorated skin flap model in rats for experimental research.

    PubMed

    Hosnuter, Mübin; Kargi, Eksal; Peksoy, Irfan; Babucçu, Orhan; Payasli, Cem

    2006-01-01

    There is a disagreement in the experimental design of random skin flaps owing to their vascular inconsistency. The definition of a reliable axial-pattern skin flap model is needed. The purpose of this study was to describe a new skin flap model to deal with entire drawbacks of existing random and axial pattern skin flap designs. This was accomplished by creating paired skin flaps including both skin and vascular pedicle on the dorsum of the same rat. This design was suitably termed as rando-axial flap. The present study offers a simple and reliable skin flap model with following advantages: (1) it has a predictable necrosis area, (2) it reveals a larger survival area (75 +/- 5%) when compared to other flaps in this study (Mann-Whitney U-test, p<0.001), (3) the vascular pedicle is consistent, (4) control and study flaps are placed on the same animal (5) it can be converted to a random, an axial or a free flap.

  12. Prefabricated vascularized bone flap: a tissue transformation technique for bone reconstruction.

    PubMed

    Alam, M I; Asahina, I; Seto, I; Oda, M; Enomoto, S

    2001-09-15

    In this study, an attempt was made to transform a muscle vascularized pedicle raised on host vessels into a vascularized bone flap, using recombinant human bone morphogenetic protein 2 (rhBMP-2). The purpose of this study was to produce new bone vascularized in nature to increase the survival rate of the subsequently grafted bone and to fabricate the newly formed bone into the desired shape. Silicone molds in the shape of a rat mandible were used to deliver rat bone matrix impregnated with or without rhBMP-2. A muscle pedicle the same size as the mold was raised on the saphenous vessels in the rat thigh and then sandwiched in the center of the silicone molds. The molds were sliced in half and each section was filled with rat bone matrix that was impregnated either with 25 microg of rhBMP-2 for the experimental group or with diluting material alone for the control group. The sandwiched flaps were then secured by tying them to the adjacent muscles and were harvested at 2 and 4 weeks after surgery. Three and six rats were used in the control and experimental groups at each time point, respectively. Bone formation was assessed in the ex vivo specimens by macroscopic, radiologic, and histologic evaluation. Macroscopically, the continuation of the vascular pedicle was clearly visible for both the control and experimental muscle flaps. However, no evidence of muscle-tissue transformation was observed in the control flaps, whereas all the flaps treated with rhBMP-2 produced new bone that replicated the shape of the mold exactly and had saphenous vessels supplying the newly formed bone. This study demonstrates that this experimental model has the potential to be therapeutically applied for effective bone reconstruction.

  13. Coverage of Amputation Stumps Using a Latissimus Dorsi Flap With a Serratus Anterior Muscle Flap: A Comparative Study.

    PubMed

    Kim, Sang Wha; Jeon, Seung Bae; Hwang, Kyu Tae; Kim, Youn Hwan

    2016-01-01

    Amputation of the extremities is a definitive reconstructive option, and surgeons should aim to preserve maximum overall function. If the exposed bone cannot be adequately covered using local tissues, the stump can be reconstructed using a number of well-described free flap transfer techniques. Between January 2002 and December 2011, 31 patients with severe injuries to the lower extremities underwent above-the-knee, below-the-knee, and Chopart and Ray amputations. Bony stumps were covered using latissimus dorsi myocutaneous flaps alone (group 1), or together with serratus anterior muscle flaps (group 2). The groups were compared with respect to age, flap survival, skin flap size, immediate complications, wound sloughing, deep ulceration, need for bone amputation, limb visual analog scale score, time to prosthesis, and follow-up duration. The mean area of the latissimus dorsi skin flap was 255.9 cm, and immediate complications occurred in 8 (25.8%) patients. In the double-padding group, there were fewer cases of deep ulceration than in the single-flap group, and prostheses could be worn sooner. There were no statistically significant differences in other parameters. Successful reconstruction of amputation stumps requires an adequate, durable, weight-bearing, and well-contoured soft tissue cover. A latissimus dorsi musculocutaneous flap together with a serratus anterior muscle flap provides well-vascularized muscle tissue and a durable skin paddle, leading to less ulceration than conventional flap techniques.

  14. Comparison of outcome of microvascular bony head and neck reconstructions using the fibular free flap and the iliac crest flap.

    PubMed

    Mücke, Thomas; Loeffelbein, Denys J; Kolk, Andreas; Wagenpfeil, Stefan; Kanatas, Anastasios; Wolff, Klaus-Dietrich; Mitchell, David A; Kesting, Marco R

    2013-09-01

    Several microvascular free flaps are available for reconstruction of the osseous components after resections for head and neck cancer. We have prospectively evaluated patients treated by bony microsurgical reconstruction to identify predictors of adverse outcomes for delayed wound healing and failure of free flaps. All patients from July 2007 to June 2011 who had reconstructions with microvascular fibular or iliac crest flaps immediately after resection of the tumour were evaluated. There were a total of 156 bony free flaps: 120 (77%) fibular and 36 (23%) iliac crest flaps. A total of 133 (85%) were successful. Delayed wound healing was more common with the iliac crest flap (p=0.01) at the intraoral site (p=0.04). Significantly more iliac crest free flaps failed (p=0.02). Anastomosis to the facial artery (p=0.05) and facial vein (p=0.04), and duration of overall operating time were associated with a significantly higher risk of failure of the flap. Patients with cancer of the head and neck who require microsurgical bony reconstruction are at increased risk of postoperative complications. Significantly more complications were found with the iliac crest flap, whereas the fibular flap was associated with a significantly longer operating time.

  15. Human FAN1 promotes strand incision in 5'-flapped DNA complexed with RPA.

    PubMed

    Takahashi, Daisuke; Sato, Koichi; Hirayama, Emiko; Takata, Minoru; Kurumizaka, Hitoshi

    2015-09-01

    Fanconi anaemia (FA) is a human infantile recessive disorder. Seventeen FA causal proteins cooperatively function in the DNA interstrand crosslink (ICL) repair pathway. Dual DNA strand incisions around the crosslink are critical steps in ICL repair. FA-associated nuclease 1 (FAN1) is a DNA structure-specific endonuclease that is considered to be involved in DNA incision at the stalled replication fork. Replication protein A (RPA) rapidly assembles on the single-stranded DNA region of the stalled fork. However, the effect of RPA on the FAN1-mediated DNA incision has not been determined. In this study, we purified human FAN1, as a bacterially expressed recombinant protein. FAN1 exhibited robust endonuclease activity with 5'-flapped DNA, which is formed at the stalled replication fork. We found that FAN1 efficiently promoted DNA incision at the proper site of RPA-coated 5'-flapped DNA. Therefore, FAN1 possesses the ability to promote the ICL repair of 5'-flapped DNA covered by RPA.

  16. Acute ischemic preconditioning of skeletal muscle prior to flap elevation augments muscle-flap survival.

    PubMed

    Carroll, C M; Carroll, S M; Overgoor, M L; Tobin, G; Barker, J H

    1997-07-01

    Ischemic preconditioning of the myocardium with repeated brief periods of ischemia and reperfusion prior to prolonged ischemia significantly reduces subsequent myocardial infarction. Following ischemic preconditioning, two "windows of opportunity" (early and late) exist, during which time prolonged ischemia can occur with reduced infarction size. The early window occurs at approximately 4 hours and the late window at 24 hours following ischemic preconditioning of the myocardium. We investigated if ischemic preconditioning of skeletal muscle prior to flap creation improved subsequent flap survival and perfusion immediately or 24 hours following ischemic preconditioning. Currently, no data exist on the utilization of ischemic preconditioning in this fashion. The animal model used was the latissimus dorsi muscle of adult male Sprague-Dawley rats. Animals were assigned to three groups, and the right or left latissimus dorsi muscle was chosen randomly in each animal. Group 1 (n = 12) was the control group, in which the entire latissimus dorsi muscle was elevated acutely without ischemic preconditioning. Group 2 (n = 8) investigated the effects of ischemic preconditioning in the early window. In this group, the latissimus dorsi muscle was elevated immediately following preconditioning. Group 3 (n = 8) investigated the effects of ischemic preconditioning in the late window, with elevation of the latissimus dorsi muscle 24 hours following ischemic preconditioning. The preconditioning regimen used in groups 2 and 3 was two 30-minute episodes of normothermic global ischemia with intervening 10-minute episodes of reperfusion. Latissimus dorsi muscle ischemia was created by occlusion of the thoracodorsal artery and vein and the intercostal perforators, after isolation of the muscle on these vessels. Muscle perfusion was assessed by a laser-Doppler perfusion imager. One week after flap elevation, muscle necrosis was quantified in all groups by means of computer-assisted digital

  17. Power performance optimization and loads alleviation with active flaps using individual flap control

    NASA Astrophysics Data System (ADS)

    Pettas, Vasilis; Barlas, Thanasis; Gertz, Drew; Madsen, Helge A.

    2016-09-01

    The present article investigates the potential of Active Trailing Edge Flaps (ATEF) in terms of increase in annual energy production (AEP) as well as reduction of fatigue loads. The basis for this study is the DTU 10 MW Reference Wind Turbine (RWT) simulated using the aeroelastic code HAWC2. In an industrial-oriented manner the baseline rotor is upscaled by 5% and the ATEFs are implemented in the outer 30% of the blades. The flap system is kept simple and robust with a single flap section and control with wind speed, rotor azimuth, root bending moments and angle of attack in flap's mid-section being the sensor inputs. The AEP is increased due to the upscaling but also further due to the flap system while the fatigue loads in components of interest (blade, tower, nacelle and main bearing) are reduced close to the level of the original turbine. The aim of this study is to demonstrate a simple and applicable method that can be a technology enabler for rotor upscaling and lowering cost of energy.

  18. Flap Necrosis after Palatoplasty in Patients with Cleft Palate

    PubMed Central

    Rossell-Perry, Percy

    2015-01-01

    Palatal necrosis after palatoplasty in patients with cleft palate is a rare but significant problem encountered by any cleft surgeon. Few studies have addressed this disastrous complication and the prevalence of this problem remains unknown. Failure of a palatal flap may be attributed to different factors like kinking or section of the pedicle, anatomical variations, tension, vascular thrombosis, type of cleft, used surgical technique, surgeon's experience, infection, and malnutrition. Palatal flap necrosis can be prevented through identification of the risk factors and a careful surgical planning should be done before any palatoplasty. Management of severe fistulas observed as a consequence of palatal flap necrosis is a big challenge for any cleft surgeon. Different techniques as facial artery flaps, tongue flaps, and microvascular flaps have been described with this purpose. This review article discusses the current status of this serious complication in patients with cleft palate. PMID:26273624

  19. Pedicled perforator flaps in the head and neck.

    PubMed

    Hofer, Stefan O P; Mureau, Marc A M

    2010-10-01

    Perforator flaps, since their first description in 1989, have in many ways revolutionized reconstructive surgery. Whereas little more than a decade ago many surgeons were still hesitant to fully trust perforator flaps to be a reliable option, nowadays these flaps are often first choice. Investigators have to remain critical, however, of their advances and realize that not every reconstruction will require or benefit from a perforator flap, as previously well-established, nonperforator flaps still have their indication and can give excellent results. The most important skill in reconstructive surgery of the head and neck is not cutting the flap but assessing the defect, planning the reconstruction, and choosing wisely from the ever-increasing options available.

  20. Dealing with the venous congestion of free flaps: venous catheterization.

    PubMed

    Gürsoy, Koray; Kankaya, Yüksel; Uysal, Afşin; Koçer, Uğur

    2008-11-01

    For head and neck reconstruction after tumor ablation surgery, free flaps are mostly the chosen treatment modality for most of the centers. Coping with venous insufficiency and increasing venous outflow of the flap during this process increases the success rate. To increase venous outflow, triple-lumen central venous catheter is inserted to one of the donor veins of the flap that has venous insufficiency and one intact vein anastomosis.

  1. Design and Control of Flapping Wing Micro Air Vehicles

    DTIC Science & Technology

    2011-09-01

    preferred solution for MAVs as the scale is reduced. 2.1 Flapping Wing Aerodynamics A hypothetical flapping wing can have up to four substantial DOF if...unsteady mechanisms depends on the forward velocity of the FWF. As the FWF speeds up , the flow over the Figure 2.1. Flapping wing kinematics...reversal and wing rotation [35, 58, 71, 72]. Therefore, similar to rapid pitch - up , wake capture is a mechanism through which the precise control of the

  2. USB noise reduction by nozzle and flap modifications

    NASA Technical Reports Server (NTRS)

    Hayden, R. E.

    1976-01-01

    The development of concepts for reducing upper surface blown flap noise at the source through flap modifications and special nozzles is reviewed. In particular, recent results obtained on the aerodynamic and acoustic performance of flaps with porous surfaces near the trailing edge and multi-slotted nozzles are reviewed. Considerable reduction (6-10 db) of the characteristic low frequency peak is shown. The aerodynamic performance is compared with conventional systems, and prospects for future improvements are discussed.

  3. Management of complications with flap procedures and replantation.

    PubMed

    Sammer, Douglas M

    2015-05-01

    Replantation and flap procedures employ microvascular techniques to salvage or reconstruct a severely damaged limb or digit. The most devastating complications include complete or partial flap loss, or replantation failure due to vascular complications. Often, these complications can be prevented by appropriate patient selection, careful surgical planning, meticulous technique, and proper postoperative management. This article discusses complications related to replantation and flap procedures in the upper limb, focusing on preventing and managing these complications.

  4. Flight test pilot evaluation of a delayed flap approach procedure

    NASA Technical Reports Server (NTRS)

    Bull, J. S.; Edwards, F. G.; Foster, J. D.; Hegarty, D. M.; Drinkwater, F. J., III

    1977-01-01

    Using NASA's CV-990 aircraft, a delayed flap approach procedure was demonstrated to nine guest pilots from the air transport industry. Four demonstration flights and 37 approaches were conducted under VFR weather conditions. A limited pilot evaluation of the delayed flap procedure was obtained from pilot comments and from questionaires they completed. Pilot acceptability, pilot workload, and ATC compatibility were quantitatively rated. The delayed flap procedure was shown to be feasible, and suggestions for further development work were obtained.

  5. Changes in the blood biochemistry following experimental flap ischaemia.

    PubMed

    Knight, K R; Gumley, G J; Rogers, I W; O'Brien, B M

    1988-05-01

    The purpose of this study was to elucidate tissue changes occurring within an ischaemic flap by monitoring the blood biochemistry, and to evaluate these changes in relation to ultimate flap viability. A rabbit epigastric free flap was made ischaemic for 4 days at 6 degrees C, then revascularized by anastomosis of its femoral artery and vein. An identical free flap immediately revascularized in another group of rabbits served as a control. The viability of the free flap, as well as various biochemical parameters studied by drawing blood from a catheter in the ear vein, were observed daily. Immediately after the revascularization of ischaemic flaps, there was a 16-fold increase in the plasma levels of creatine kinase (CK) and a smaller but significant 1.5-fold to 2.0-fold increase in lactate dehydrogenase (LDH) and aspartate aminotransferase (AST). In flaps which ultimately failed by 7 days post-ischaemia, the plasma levels of CK, LDH and AST peaked at day 2 post-ischaemia at 68, 13 and 8 times normal respectively, whereas in flaps which survived, the levels of these enzymes recovered to normal by day 3 post-ischaemia. These enzymic changes are probably due to a combination of ischaemic changes in the flap vasculature, ischaemic changes in the flap muscle, and inflammatory changes in the surrounding abdominal tissue. The plasma levels of CK at any time post-ischaemia, and particularly in the first 24 h, were significantly higher in ischaemic flaps which failed compared with those which survived. This parameter is therefore proposed as a possible means of predicting potential flap failure after ischaemic insult, in time to make appropriate surgical intervention.

  6. Microdialysis in clinical practice: monitoring intraoral free flaps.

    PubMed

    Jyränki, Janne; Suominen, Sinikka; Vuola, Jyrki; Bäck, Leif

    2006-04-01

    Clinical examination is still the gold standard of postoperative free flap monitoring, but with intraorally situated and/or buried flaps, it can be difficult or impossible. Microdialysis is a sampling technique which offers the possibility to monitor the metabolism of a flap continuously. Ischemia can be detected by monitoring the changes in glucose, lactate, and pyruvate levels in interstitial fluid of the specific tissue. Our aim was to use microdialysis to monitor the metabolism of free flaps used for reconstructions inside the oral cavity/oropharynx and to evaluate the reliability and usefulness of this new monitoring method.Twenty-five consecutive patients who underwent oral cavity/oropharynx cancer resection and immediate reconstruction with free flap were included in the study. A microdialysis catheter was placed into the subcutaneous adipose tissue of the flap in the end of the surgical procedure. Dialysate samples were taken on an hourly basis for 72 hours postoperatively. Routine clinical monitoring was carried out by experienced nursing staff. Clinical findings were recorded and later compared with microdialysis values. Two flaps out of 25 failed in spite of reoperations. In both problem cases, microdialysis indicated ischemia 1 to 2 hours before it became clinically evident. During flap ischemia, the lactate/pyruvate ratio increased, glucose concentrations reduced, whereas lactate level increased when compared with normal values. Our results indicate that microdialysis is safe for the patient and the flap. It can reliably detect flap ischemia at an early stage. This is especially useful in buried flaps when clinical monitoring is difficult. Microdialysis may also reduce the patient discomfort caused by repeated clinical examination of the flap.

  7. Blade-Vortex Interaction Noise Characteristics of a Full-Scale Active Flap Rotor

    DTIC Science & Technology

    2009-01-01

    vibration control, a more inboard flap position was more efficient. Smaller flap chord ratios (15%) were preferred as a compromise between control... ratio . The constant chord section of the blade is 10 inches long. Nominal rotation speed of the rotor is 392 RPM producing a tip speed of 695 ft/sec...minimum actuator power. The flap system selected [25] has a flap/chord ratio of 25% with an overhang of 40% (total flap length of 35% chord) and flap

  8. Forward speed effects on blown flap noise

    NASA Technical Reports Server (NTRS)

    Pennock, A. P.

    1977-01-01

    The effects of forward speed on the noise of under-the-wing (externally blown flaps, EBF) and over-the-wing (upper surface blown, USB) blown flap configurations were measured in wind tunnel model tests with cold jets. The results are presented without correction for the effects (e.g., signal convection, shear layer refraction) associated with flight simulation in a wind tunnel or free jet facility. Noise decreases were generally observed at microphones forward of the wing. The reductions were larger at the low frequencies (below peak SPL) than at the high (above peak SPL). Noise increases of 10 dB or more were observed at the aft microphones, especially in the high frequency range.

  9. Thumb reconstruction with extended twisted toe flap.

    PubMed

    Iglesias, M; Butron, P; Serrano, A

    1995-09-01

    Twelve amputated thumbs were reconstructed with a neurovascular cutaneous flap from the great toe and an osteotendinous flap from the second toe. Both transfers were dependent on a single vascular pedicle. One of the 12 reconstructions failed. In the remaining 11, the mobility of the metacarpophalangeal joint ranged from 10 degrees to 50 degrees, and that of the interphalangeal joint from 10 degrees to 30 degrees. Opposition and key pinch were restored, and the shape and volume were similar to those of the normal thumb. Likewise, the great toe was preserved, and all patients had a normal gait. This technique preserves the epiphyses for future growth in children and maintains the aesthetic appearance of the foot, but it has the disadvantage of involving a lengthy surgical procedure with a 17% rate of major complications.

  10. Pumping by flapping in a viscoelastic fluid.

    PubMed

    Pak, On Shun; Normand, Thibaud; Lauga, Eric

    2010-03-01

    In a world without inertia, Purcell's scallop theorem states that in a Newtonian fluid a time-reversible motion cannot produce any net force or net flow. Here we consider the extent to which the nonlinear rheological behavior of viscoelastic fluids can be exploited to break the constraints of the scallop theorem in the context of fluid pumping. By building on previous work focusing on force generation, we consider a simple, biologically inspired geometrical example of a flapper in a polymeric (Oldroyd-B) fluid, and calculate asymptotically the time-average net fluid flow produced by the reciprocal flapping motion. The net flow occurs at fourth order in the flapping amplitude, and suggests the possibility of transporting polymeric fluids using reciprocal motion in simple geometries even in the absence of inertia. The induced flow field and pumping performance are characterized and optimized analytically. Our results may be useful in the design of micropumps handling complex fluids.

  11. [Fundamentals and principles of grafts and flaps].

    PubMed

    Cruz-Navarro, Natalio; León-Dueñas, Eduardo

    2014-01-01

    Reconstructive surgery of large urethral stenosis and the management of congenital anomalies such as hypospadias and epispadias require covering large cutaneous and mucosal defects with different techniques. The objective of this work is to define the main differences between tissues to be transferred and to study the principles that must govern the management of the various flaps and grafts used for these techniques. We analyze the anatomical and physiological features that may be key to understand the success and possible failures of these procedures, and we review technical details that must accompany in every case, not only during the operation, but also during the preoperative and postoperative period. We conclude stating that grafts (mainly oral and preputial mucosa) and flaps are increasingly used for the repair of urethral stenosis. Grafts must be prepared adequately in the back table and thinned to the maximum, and also be fixed properly, to guarantee their immobility until neovascularization is assured.

  12. A novel animal model for skin flap prelamination with biomaterials

    NASA Astrophysics Data System (ADS)

    Zhou, Xianyu; Luo, Xusong; Liu, Fei; Gu, Chuan; Wang, Xi; Yang, Qun; Qian, Yunliang; Yang, Jun

    2016-09-01

    Several animal models of skin flap construction were reported using biomaterials in a way similar to prefabrication. However, there are few animal model using biomaterials similar to prelamination, another main way of clinical skin flap construction that has been proved to be reliable. Can biomaterials be added in skin flap prelamination to reduce the use of autogenous tissues? Beside individual clinical attempts, animal model is needed for randomized controlled trial to objectively evaluate the feasibility and further investigation. Combining human Acellular Dermal Matrix (hADM) and autologous skin graft, we prelaminated flaps based on inguinal fascia. One, two, three and four weeks later, hADM exhibited a sound revascularization and host cell infiltration. Prelaminated skin flaps were then raised and microsurgically transplanted back to groin region. Except for flaps after one week of prelamination, flaps from other subgroups successfully reconstructed defects. After six to sixteen weeks of transplantation, hADM was proved to being able to maintain its original structure, having a wealth of host tissue cells and achieving full revascularization.To our knowledge, this is the first animal model of prelaminating skin flap with biomaterials. Success of this animal model indicates that novel flap prelamination with biomaterials is feasible.

  13. Clinical Experiences with the Scapular Fascial Free Flap

    PubMed Central

    Park, Il Ho; Chang, Yong Joon; Kim, Jae Hyun

    2016-01-01

    Background The goal of reconstruction is to provide coverage of exposed vital structures with well-vascularized tissue for optimal restoration of form and function. Here, we present our clinical experience with the use of the scapular fascial free flap to correct facial asymmetry and to reconstruct soft tissue defects of the extremities. Methods We used a scapular fascial free flap in 12 cases for soft tissue coverage of the extremities or facial soft tissue augmentation. Results The flaps ranged in size from 3×12 to 13×23 cm. No cases of total loss of the flap occurred. Partial loss of the flap occurred in 1 patient, who was treated with a turnover flap using the adjacent scapular fascial flap and a skin graft. Partial loss of the skin graft occurred in 4 patients due to infection or hematoma beneath the graft, and these patients underwent another skin graft. Four cases of seroma at the donor site occurred, and these cases were treated with conservative management or capsulectomy and quilting sutures. Conclusions The scapular fascial free flap has many advantages, including a durable surface for restoration of form and contours, a large size with a constant pedicle, adequate surface for tendon gliding, and minimal donor-site scarring. We conclude that despite the occurrence of a small number of complications, the scapular fascial free flap should be considered to be a viable option for soft tissue coverage of the extremities and facial soft tissue augmentation. PMID:27689051

  14. Translational damping on high-frequency flapping wings

    NASA Astrophysics Data System (ADS)

    Parks, Perry A.

    Flapping fliers such as insects and birds depend on passive translational and rotational damping to terminate quick maneuvers and to provide a source of partial stability in an otherwise unstable dynamic system. Additionally, passive translational and rotational damping reduce the amount of active kinematic changes that must be made to terminate maneuvers and maintain stability. The study of flapping-induced damping phenomena also improves the understanding of micro air vehicle (MAV) dynamics needed for the synthesis of effective flight control strategies. Aerodynamic processes which create passive translational and rotational damping as a direct result of symmetric flapping with no active changes in wing kinematics have been previously studied and were termed flapping counter-force (FCF) and flapping counter-torque (FCT), respectively. In this first study of FCF measurement in air, FCF generation is measured using a pendulum system designed to isolate and measure the relationship of translational flapping-induced damping with wingbeat frequency for a 2.86 gram mechanical flapper equipped with real cicada wings. Analysis reveals that FCF generation and wingbeat frequency are directly proportional, as expected from previous work. The quasi-steady FCF model using Blade-Element-Theory is used as an estimate for translational flapping-induced damping. In most cases, the model proves to be accurate in predicting the relationship between flapping-induced damping and wingbeat frequency. "Forward-backward" motion proves to have the strongest flapping-induced damping while "up-down" motion has the weakest.

  15. Optical spectroscopic assessment of free flap circulatory impairment

    NASA Astrophysics Data System (ADS)

    Sowa, Michael G.; Payette, Jeri R.; Kohlenberg, Elicia; Leonardi, Lorenzo; Pabbies, Arone; Kerr, Paul

    2004-10-01

    Free flaps are used to reconstruct tissue damaged by injury. Circulatory impairment of the free flap is the leading cause of a failed flap surgery. This study demonstrates that optical spectroscopy can detect early signs of circulatory impairment and distinguish between arterial or venous blockage. An epigastric flap model is used to mimic conditions of both arterial and venous circulatory impairment. Animals were divided into three groups 1.) arterial occlusion (n=5), 2.) venous occlusion (n=4), and 3.) control (n=5). A classifier was applied to the reflectance data to determine whether there were consistent differences between the three study groups. The classifier was able to distinguish between arterial occlusion, venous occlusion and healthy flaps with a 95% accuracy. Measures of hemoglobin oxygen saturation and blood volume were derived from the same reflectance data. Oxygenation of the flap was significantly lower during venous or arterial occlusion compared to control flaps. Blood volume of the free flap went up significantly following venous blockage while blockage of the artery cause a significant drop in blood volume. Combining the predictions of the classifier and examining the oxygenation and blood volume parameters reliably detected circulatory impairment of the free flap.

  16. [Expanded pedicled forearm flap for reconstruction of multiple finger amputations].

    PubMed

    Alvarez Jorge, A; Martelo Villar, F

    2000-05-01

    Soft-tissue injuries of the hand frequently require flap coverage to preserve structures damaged at the time of injury or to facilitate later reconstruction. The radial forearm flap makes local tissue readily available and offers a simple method of reconstruction. Secondary augmentation of the skin flap by means of tissue expansion appears to be a useful alternative to improve the possibilities of reconstruction. This case report describes a primary reconstruction of a hand with multiple finger amputations using both techniques: Forearm flap and tissue expansion.

  17. Autologous breast reconstruction with the extended latissimus dorsi flap.

    PubMed

    Chang, David W; Youssef, Adel; Cha, Sumi; Reece, Gregory P

    2002-09-01

    The extended latissimus dorsi myocutaneous flap can provide autogenous tissue replacement of breast volume without an implant. Nevertheless, experience with the extended latissimus dorsi flap for breast reconstruction is relatively limited. In this study, the authors evaluated their experience with the extended latissimus dorsi flap for breast reconstruction to better understand its indications, limitations, complications, and clinical outcomes. All patients who underwent breast reconstruction with extended latissimus dorsi flaps at the authors' institution between January of 1990 and December of 2000 were reviewed. During the study period, 75 extended latissimus dorsi flap breast reconstructions were performed in 67 patients. Bilateral breast reconstructions were performed in eight patients, and 59 patients underwent unilateral breast reconstruction. There were 45 immediate and 30 delayed reconstructions. Mean patient age was 51.5 years. Mean body mass index was 31.8 kg/m2. Flap complications developed in 21 of 75 flaps (28.0 percent), and donor-site complications developed in 29 of 75 donor sites (38.7 percent). Mastectomy skin flap necrosis (17.3 percent) and donor-site seroma (25.3 percent) were found to be the most common complications. There were no flap losses. Patients aged 65 years or older had higher odds of developing flap complications compared with those 45 years or younger (p = 0.03). Patients with size D reconstructed breasts had significantly higher odds of flap complications compared with those with size A or B reconstructed breasts (p = 0.05). Obesity (body mass index greater than or equal to 30 kg/m2) was associated with a 2.15-fold increase in the odds of developing donor-site complications compared with patients with a body mass index less than 30 kg/m2 (p = 0.01). No other studied factors had a significant relationship with flap or donor-site complications. In most patients, the extended latissimus dorsi flap alone, without an implant, can

  18. Staged retroauricular flap for helical reconstruction after Mohs micrographic surgery*

    PubMed Central

    Cerci, Felipe Bochnia

    2016-01-01

    Staged retroauricular flap is a great option for full-thickness defects along the helical rim and antihelix. Donor site consists of the posterior ear, postauricular sulcus and mastoid area. The advantages of this flap include hidden donor scar, donor tissue similarity and rich vascularity. We present a case of collision tumor on the left helix treated with Mohs micrographic surgery and the resulting full-thickness defect repaired with a staged retroauricular flap. This flap is an effective technique for full-thickness helical defect repair with relatively little operative morbidity. High esthetic and functional results may be obtained restoring the ear size and shape.

  19. Perforator Flaps for Reconstruction of Lower Limb Defects

    PubMed Central

    Yasir, Mir; Wani, Adil Hafeez; Zargar, Haroon Rashid

    2017-01-01

    BACKGROUND Reconstruction of soft tissue defects in the lower third of the leg remains challenging. Anatomical constraints limit the local options available for complex defects especially lower third of leg. Local flaps based on perforator vessels are raising interest in reconstructive surgery of the limbs. We present our experience with perforator flaps for reconstruction of soft tissue defects in the lower limb. METHODS The study was carried prospectively and 23 patients with lower limb defects treated with various perforator flaps (both elective as well as emergency) were included in the study. A hand-held ultrasound Doppler was used preoperatively and intraoperatively to detect the perforator vessels. RESULTS Out of 23 patients, we witnessed partial flap loss in 1 and distal flap necrosis in 3 patients. Four patients had minor complications which included infection, wound dehiscence and congestion of flap. CONCLUSION Perforator flaps may represent a good alternative to the free flaps in the areas were other local reconstructive procedures are not possible. This is a versatile technique and with decreased donor site morbidity limited to a single body area. There is a specific like to like soft tissue replacement leading to a better cosmetic and reconstructive outcome. The main drawback of the perforator flaps however is the higher risk of venous congestion. PMID:28289617

  20. Generation of the vorticity field by the flapping profile

    NASA Astrophysics Data System (ADS)

    Kozlowski, T.; Kudela, H.

    2016-10-01

    Birds and insects move due to flapping their wings. In the paper we presented unsteady effects that led to the lift and thrust force generation on the flapping foil. It was assumed that the flow was two-dimensional. We demonstrated that flapping motion with low Reynolds produced well-ordered vorticity around the profile. The well-ordered vorticity atmosphere generates predictable aerodynamic force distribution on the profile. We demonstrated that high enough parameters of flapping motion caused the disordered vorticity distribution around the profiles that led to the loss of the lift force and limited the possibility of a flight.

  1. Perineoscrotal reconstruction using a medial circumflex femoral artery perforator flap.

    PubMed

    Karsidag, Semra; Akcal, Arzu; Sirvan, Selami Serhat; Guney, Soner; Ugurlu, Kemal

    2011-02-01

    Major scrotal defects may result from infection due to Fournier's gangrene, excision of scrotal skin diseases, traumatic avulsion of scrotal and penile skin, and genital burns. The wide spectrum of bacterial flora of the perineum, difficulty in providing immobilisation, and obtaining a natural contour of the testes make testicular cover very difficult. Various methods have been reported to cover the penoscrotal area, including skin grafting, transposing them to medial thigh skin, and use of local fasciocutaneous or musculocutaneous flaps. In this report, reconstruction using six local medial circumflex femoral artery perforator (MCFAP) flaps was undertaken in five male patients (mean age, 47 years) with complex penoscrotal or perineal wounds. The cause of the wounds in four patients was Fournier's gangrene, and was a wide papillomateous lesion in the other patient. Flap width was 6-10 cm and flap length was 10-18 cm. The results showed that a MCFAP flap provided the testes with a pliable local flap without being bulky and also protected the testicle without increasing the temperature. The other advantage of the MCFAP flap was that the donor-site scar could be concealed in the gluteal crease. Our results demonstrated that the MCFAP flap is an ideal local flap for covering penoscrotal defects.

  2. A novel animal model for skin flap prelamination with biomaterials

    PubMed Central

    Zhou, Xianyu; Luo, Xusong; Liu, Fei; Gu, Chuan; Wang, Xi; Yang, Qun; Qian, Yunliang; Yang, Jun

    2016-01-01

    Several animal models of skin flap construction were reported using biomaterials in a way similar to prefabrication. However, there are few animal model using biomaterials similar to prelamination, another main way of clinical skin flap construction that has been proved to be reliable. Can biomaterials be added in skin flap prelamination to reduce the use of autogenous tissues? Beside individual clinical attempts, animal model is needed for randomized controlled trial to objectively evaluate the feasibility and further investigation. Combining human Acellular Dermal Matrix (hADM) and autologous skin graft, we prelaminated flaps based on inguinal fascia. One, two, three and four weeks later, hADM exhibited a sound revascularization and host cell infiltration. Prelaminated skin flaps were then raised and microsurgically transplanted back to groin region. Except for flaps after one week of prelamination, flaps from other subgroups successfully reconstructed defects. After six to sixteen weeks of transplantation, hADM was proved to being able to maintain its original structure, having a wealth of host tissue cells and achieving full revascularization.To our knowledge, this is the first animal model of prelaminating skin flap with biomaterials. Success of this animal model indicates that novel flap prelamination with biomaterials is feasible. PMID:27659066

  3. 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.

  4. Skew flap for staged below-knee amputation in sepsis.

    PubMed

    Matthews, Christopher O; Williams, Ian M; Lewis, Peter; McLain, A David; Twine, Christopher P

    2016-04-01

    Skew flap amputation was first described in the 1980s but was never as popular as the long posterior flap amputation. This report describes a staged below-knee amputation in sepsis, with pus throughout the leg and a lack of skin coverage. One benefit of skew flaps never previously published is the fact that the suture line is not directly over the tibia. Therefore, an open wound or incomplete skin coverage is not as important as in long posterior flaps where it often leads to bone exposure and revision amputation. These benefits were utilized in this case leading to stump healing.

  5. Theoretical and experimental study on the ejector augmented jet flap

    NASA Technical Reports Server (NTRS)

    Stewart, H. J.

    1974-01-01

    The analytical concept used in determining the characteristics of jet flap or related propulsive systems suitable for VTOL and STOL applications was examined. The configuration chosen was a two dimensional wing with a biplane flap, having a jet injected on the upper surface of the wing at the flap hinge axis and discharging into the channel between the two elements of the flap. The experimental work was conducted in a two dimensional test installation in a subsonic wind tunnel. The model description, the test conditions, and a summary of the experimental results are presented.

  6. Numerical analysis of the V-Y shaped advancement flap.

    PubMed

    Remache, D; Chambert, J; Pauchot, J; Jacquet, E

    2015-10-01

    The V-Y advancement flap is a usual technique for the closure of skin defects. A triangular flap is incised adjacent to a skin defect of rectangular shape. As the flap is advanced to close the initial defect, two smaller defects in the shape of a parallelogram are formed with respect to a reflection symmetry. The height of the defects depends on the apex angle of the flap and the closure efforts are related to the defects height. Andrades et al. 2005 have performed a geometrical analysis of the V-Y flap technique in order to reach a compromise between the flap size and the defects width. However, the geometrical approach does not consider the mechanical properties of the skin. The present analysis based on the finite element method is proposed as a complement to the geometrical one. This analysis aims to highlight the major role of the skin elasticity for a full analysis of the V-Y advancement flap. Furthermore, the study of this technique shows that closing at the flap apex seems mechanically the most interesting step. Thus different strategies of defect closure at the flap apex stemming from surgeon's know-how have been tested by numerical simulations.

  7. Development of a morphing flap using shape memory alloy actuators: the aerodynamic characteristics of a morphing flap

    NASA Astrophysics Data System (ADS)

    Ko, Seung-Hee; Bae, Jae-Sung; Rho, Jin-Ho

    2014-07-01

    The discontinuous contour of a wing with conventional flaps diminishes the aerodynamic performance of an aircraft. A wing with a continuous contour does not experience extreme flow stream fluctuations during flight, and consequently has good aerodynamic characteristics. In this study, a morphing flap using shape memory alloy actuators is proposed, designed and fabricated, and its aerodynamic characteristics are investigated using aerodynamic analyses and wind tunnel tests. The ribs of the morphing flap are designed and fabricated with multiple elements joined together in a way that allows relative rotations of adjacent elements and forms a smooth contour of the morphing flap. The aerodynamic analyses of this multiple-element morphing-flap wing are performed using XFLR pro; its aerodynamic performance is compared with that of a mechanical-flap wing, and is measured through wind-tunnel tests.

  8. Calculation of the longitudinal aerodynamic characteristics of wing-flap configurations with externally blown flaps

    NASA Technical Reports Server (NTRS)

    Mendenhall, M. R.

    1976-01-01

    An analytical method for predicting the longitudinal aerodynamic characteristics of externally blown flap configurations is described. Two potential flow models make up the prediction method: a wing and flap lifting-surface model and a turbofan engine wake model. A vortex-lattice lifting-surface method is used to represent the wing and multiple-slotted trailing-edge flaps. The jet wake is represented by a series of closely spaced vortex rings normal to a centerline which is free to move to conform to the local flow field. The two potential models are combined in an iterative fashion to predict the jet wake interference effects on a typical EBF configuration. Comparisons of measured and predicted span-load distributions, individual surface forces, forces and moments on the complete configuration, and flow fields are included.

  9. Aerodynamics of high frequency flapping wings

    NASA Astrophysics Data System (ADS)

    Hu, Zheng; Roll, Jesse; Cheng, Bo; Deng, Xinyan

    2010-11-01

    We investigated the aerodynamic performance of high frequency flapping wings using a 2.5 gram robotic insect mechanism developed in our lab. The mechanism flaps up to 65Hz with a pair of man-made wing mounted with 10cm wingtip-to-wingtip span. The mean aerodynamic lift force was measured by a lever platform, and the flow velocity and vorticity were measured using a stereo DPIV system in the frontal, parasagittal, and horizontal planes. Both near field (leading edge vortex) and far field flow (induced flow) were measured with instantaneous and phase-averaged results. Systematic experiments were performed on the man-made wings, cicada and hawk moth wings due to their similar size, frequency and Reynolds number. For insect wings, we used both dry and freshly-cut wings. The aerodynamic force increase with flapping frequency and the man-made wing generates more than 4 grams of lift at 35Hz with 3 volt input. Here we present the experimental results and the major differences in their aerodynamic performances.

  10. Managing Flap Vortices via Separation Control

    NASA Technical Reports Server (NTRS)

    Greenblatt, David

    2006-01-01

    A pilot study was conducted on a flapped semi-span model to investigate the concept and viability of near-wake vortex management by means of boundary layer separation control. Passive control was achieved using a simple fairing and active control was achieved via zero mass-flux blowing slots. Vortex sheet strength, estimated by integrating surface pressures, was used to predict vortex characteristics based on inviscid rollup relations and vortices trailing the flaps were mapped using a seven-hole probe. Separation control was found to have a marked effect on vortex location, strength, tangential velocity, axial velocity and size over a wide range of angles of attack and control conditions. In general, the vortex trends were well predicted by the inviscid rollup relations. Manipulation of the separated flow near the flap edges exerted significant control over either outboard or inboard edge vortices while producing small lift and moment excursions. Unsteady surface pressures indicated that dynamic separation and attachment control can be exploited to perturb vortices at wavelengths shorter than a typical wingspan. In summary, separation control has the potential for application to time-independent or time-dependent wake alleviation schemes, where the latter can be deployed to minimize adverse effects on ride-quality and dynamic structural loading.

  11. Locomotion of a flapping flexible plate

    NASA Astrophysics Data System (ADS)

    Hua, Ru-Nan; Zhu, Luoding; Lu, Xi-Yun

    2013-12-01

    The locomotion of a flapping flexible plate in a viscous incompressible stationary fluid is numerically studied by an immersed boundary-lattice Boltzmann method for the fluid and a finite element method for the plate. When the leading-edge of the flexible plate is forced to heave sinusoidally, the entire plate starts to move freely as a result of the fluid-structure interaction. Mechanisms underlying the dynamics of the plate are elucidated. Three distinct states of the plate motion are identified and can be described as forward, backward, and irregular. Which state to occur depends mainly on the heaving amplitude and the bending rigidity of the plate. In the forward motion regime, analysis of the dynamic behaviors of the flapping flexible plate indicates that a suitable degree of flexibility can improve the propulsive performance. Moreover, there exist two kinds of vortex streets in the downstream of the plate which are normal and deflected wake. Further the forward motion is compared with the flapping-based locomotion of swimming and flying animals. The results obtained in the present study are found to be consistent with the relevant observations and measurements and can provide some physical insights into the understanding of the propulsive mechanisms of swimming and flying animals.

  12. Flapping inertia for selected rotor blades

    NASA Technical Reports Server (NTRS)

    Berry, John D.; May, Matthew J.

    1991-01-01

    Aerodynamics of helicopter rotor systems cannot be investigated without consideration for the dynamics of the rotor. One of the principal properties of the rotor which affects the rotor dynamics is the inertia of the rotor blade about its root attachment. Previous aerodynamic investigation have been performed on rotor blades with a variety of planforms to determine the performance differences due to blade planform. The blades tested for this investigation have been tested on the U.S. Army 2 meter rotor test system (2MRTS) in the NASA Langley 14 by 22 foot subsonic tunnel for hover performance. This investigation was intended to provide fundamental information on the flapping inertia of five rotor blades with differing planforms. The inertia of the bare cuff and the cuff with a blade extension were also measured for comparison with the inertia of the blades. Inertia was determined using a swing testing technique, using the period of oscillation to determine the effective flapping inertia. The effect of damping in the swing test was measured and described. A comparison of the flapping inertials for rectangular and tapered planform blades of approximately the same mass showed the tapered blades to have a lower inertia, as expected.

  13. Mastectomy skin flap necrosis: challenges and solutions

    PubMed Central

    Robertson, Stuart A; Jeevaratnam, Johann A; Agrawal, Avi; Cutress, Ramsey I

    2017-01-01

    Introduction Mastectomy skin flap necrosis (MSFN) has a reported incidence of 5%–30% in the literature. It is often a significant and underappreciated problem. The aim of this article was to review the associated challenges and possible solutions. Methods A MEDLINE search was performed using the search term “mastectomy skin flap necrosis”. Titles and abstracts from peer-reviewed publications were screened for relevance. Results MSFN is a common complication and may present as partial- or full-thickness necrosis. Predictive patient risk factors include smoking, diabetes, obesity, radiotherapy, previous scars and severe medical comorbidity. MSFN leads to a number of challenges, including wound management problems, delays to adjuvant therapy, esthetic compromise, implant extrusion, patient distress and financial loss. Careful preoperative planning and meticulous surgical technique may reduce the incidence of MSFN. A number of intraoperative techniques are available to try and predict skin flaps at risk of MSFN. MSFN may be managed operatively or nonoperatively. Early intervention may reduce the morbidity of MSFN in selected cases. Topical nitroglycerin ointment may be beneficial in reducing MSFN following immediate reconstruction, but the evidence base is still limited. Conclusion MSFN can result in considerable challenges for the patient and the health care service. This review discusses the management options for this problem. PMID:28331365

  14. 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.

  15. Complex lower face reconstruction using a combined technique of Estlander flap and subscapular artery system free flaps.

    PubMed

    Hamahata, Atsumori; Saitou, Takashi; Beppu, Takeshi; Shirakura, Satoshi; Hatanaka, Akio; Yamaki, Takashi; Sakurai, Hiroyuki

    2013-12-01

    When advanced mandibular carcinoma is resected, the defect may include lip and oral commissure. Free flap insertion is commonly used to reconstruct the lip defect. Although improvements in the oral reconstructive method via free flap use have been reported, functional and aesthetic results of the oral sphincter remain limited. This case report describes two individuals presenting with massive lower face defects, including a lower lip defect and a mandibular bone defect. Reconstruction was accomplished using the Estlander flap and free subscapular system of flaps. In both cases, the free subscapular artery system flap was elevated from the mandibular bone defect and other mucosal defect. The lower lip and oral commissure defect was reconstructed via Estlander flap. Free flaps survived 100% and both cases healed without complication. Patients regained good oral sphincter function with no reports of drooling. Thus, in cases involving massive lower face resection, including that of the lower lip and mandibular bone, this method of reconstruction when combined with lip-switch flap and subscapular artery system flap can prove to be useful.

  16. Elastic deformation and energy loss of flapping fly wings.

    PubMed

    Lehmann, Fritz-Olaf; Gorb, Stanislav; Nasir, Nazri; Schützner, Peter

    2011-09-01

    During flight, the wings of many insects undergo considerable shape changes in spanwise and chordwise directions. We determined the origin of spanwise wing deformation by combining measurements on segmental wing stiffness of the blowfly Calliphora vicina in the ventral and dorsal directions with numerical modelling of instantaneous aerodynamic and inertial forces within the stroke cycle using a two-dimensional unsteady blade elementary approach. We completed this approach by an experimental study on the wing's rotational axis during stroke reversal. The wing's local flexural stiffness ranges from 30 to 40 nN m(2) near the root, whereas the distal wing parts are highly compliant (0.6 to 2.2 nN m(2)). Local bending moments during wing flapping peak near the wing root at the beginning of each half stroke due to both aerodynamic and inertial forces, producing a maximum wing tip deflection of up to 46 deg. Blowfly wings store up to 2.30 μJ elastic potential energy that converts into a mean wing deformation power of 27.3 μW. This value equates to approximately 5.9 and 2.3% of the inertial and aerodynamic power requirements for flight in this animal, respectively. Wing elasticity measurements suggest that approximately 20% or 0.46 μJ of elastic potential energy cannot be recovered within each half stroke. Local strain energy increases from tip to root, matching the distribution of the wing's elastic protein resilin, whereas local strain energy density varies little in the spanwise direction. This study demonstrates a source of mechanical energy loss in fly flight owing to spanwise wing bending at the stroke reversals, even in cases in which aerodynamic power exceeds inertial power. Despite lower stiffness estimates, our findings are widely consistent with previous stiffness measurements on insect wings but highlight the relationship between local flexural stiffness, wing deformation power and energy expenditure in flapping insect wings.

  17. Microvascular Fragment Transplantation Improves Rat Dorsal Skin Flap Survival

    PubMed Central

    Rathbone, Christopher R.

    2016-01-01

    Background: The development of flap necrosis distally remains a concern during microsurgical flap transfers because, at least in part, of decreased perfusion. Microvascular fragments (MVFs) are microvessels isolated from adipose tissue that are capable of improving tissue perfusion in a variety of tissue defects. The aim of this study was to determine whether the transplantation of MVFs in a dorsal rat skin flap model can improve flap survival. Methods: A 10 × 3 cm flap was raised in a cranial to caudal fashion on the dorsal side of 16 Lewis rats, with the caudal side remaining intact. The rats were equally divided into a treatment group (MVFs) and a control group (sterile saline). At the time of surgery, sterile saline with or without MVFs was injected directly into the flap. Microvessel density was determined after harvesting flap tissue by counting vessels that positively stained for Griffonia simplicifolia lectin I-isolectin B4. Laser Doppler was used to measure blood flow before and after surgery and 7 and 14 days later. Flap survival was evaluated 7 and 14 days after surgery by evaluating the percentage of viable tissue of the flap with photodigital planimetry. Results: Despite the lack of a significant difference in microvessel density and tissue perfusion, flap survival increased 6.4% (P < 0.05) in MVF-treated animals compared with controls. Conclusions: The use of MVFs may be a means to improve flap survival. Future studies are required to delineate mechanisms whereby this occurs and to further optimize their application. PMID:28293502

  18. Folding in and out: passive morphing in flapping wings.

    PubMed

    Stowers, Amanda K; Lentink, David

    2015-03-25

    We present a new mechanism for passive wing morphing of flapping wings inspired by bat and bird wing morphology. The mechanism consists of an unactuated hand wing connected to the arm wing with a wrist joint. Flapping motion generates centrifugal accelerations in the hand wing, forcing it to unfold passively. Using a robotic model in hover, we made kinematic measurements of unfolding kinematics as functions of the non-dimensional wingspan fold ratio (2-2.5) and flapping frequency (5-17 Hz) using stereo high-speed cameras. We find that the wings unfold passively within one to two flaps and remain unfolded with only small amplitude oscillations. To better understand the passive dynamics, we constructed a computer model of the unfolding process based on rigid body dynamics, contact models, and aerodynamic correlations. This model predicts the measured passive unfolding within about one flap and shows that unfolding is driven by centrifugal acceleration induced by flapping. The simulations also predict that relative unfolding time only weakly depends on flapping frequency and can be reduced to less than half a wingbeat by increasing flapping amplitude. Subsequent dimensional analysis shows that the time required to unfold passively is of the same order of magnitude as the flapping period. This suggests that centrifugal acceleration can drive passive unfolding within approximately one wingbeat in small and large wings. Finally, we show experimentally that passive unfolding wings can withstand impact with a branch, by first folding and then unfolding passively. This mechanism enables flapping robots to squeeze through clutter without sophisticated control. Passive unfolding also provides a new avenue in morphing wing design that makes future flapping morphing wings possibly more energy efficient and light-weight. Simultaneously these results point to possible inertia driven, and therefore metabolically efficient, control strategies in bats and birds to morph or recover

  19. Intraoperative Flap Complications in LASIK Surgery Performed by Ophthalmology Residents

    PubMed Central

    Romero-Diaz-de-Leon, Lorena; Serna-Ojeda, Juan Carlos; Navas, Alejandro; Graue-Hernández, Enrique O.; Ramirez-Miranda, Arturo

    2016-01-01

    Purpose: To report the rate of flap-related complications in LASIK surgery performed by in-training ophthalmology residents and to analyze the risk factors for these complications. Methods: We analyzed 273 flap dissections in 145 patients from March 2013 to February 2014. We included all LASIK surgeries performed by 32 ophthalmology residents using a Moria M2 microkeratome. All the flap-related complications were noted. Comparison between both groups with and without complications was performed with an independent Student's t-test and relative risks were calculated. Results: There were 19 flap-related complications out of the 273 flap dissections (6.95%). The most common complication was incomplete flap dissection (n = 10; 3.66%), followed by free-cap (n = 5; 1.83%), and flap-buttonhole (n = 2; 0.73%). There was no significant difference between the complicated and uncomplicated cases in terms of the right versus the left eye, pachymetry results, white-to-white diameter, and spherical equivalent. But this difference was significant for mean keratometry (P = 0.008), K-min (P = 0.01), and K-max (P = 0.03) between these groups. Final visual acuity after rescheduling laser treatment was similar in both groups. Relative risks for flap-related complications were 2.03 for the first LASIK surgery (CI 95% 0.64 to 6.48; P = 0.22) and 1.26 (CI 95% 0.43 to 3.69; P = 0.66) for the surgeon's flap-related complications. Female gender presented an odds ratio of 2.48 (CI 95% 0.68 to 9.00; P = 0.16) for complications. Conclusion: Flap-related complications are common intraoperative event during LASIK surgery performed by in-training ophthalmologists. Keratometries and surgeon's first procedure represent a higher probability for flap related complications than some other biometric parameters of patient's eye. PMID:27621782

  20. Complex technique of large sural flap: an alternative option for free flap in large defect of the traumatized foot.

    PubMed

    Mohammadkhah, Naser; Motamed, Sadrollah; Hosseini, Seyed Nejat; Hallajmofrad, Hamid Reza; Abdolzadeh, Madjid; Afzali Borujeni, Lotfallah; Mousavinasab, Seyednouraddin

    2011-01-01

    The distally based sural fasciocutaneous flap has become a main part of the reconstruction of the lower leg, heel and foot. However, perfusion problems and venous congestion have been reported. Over the past decade, several flap modifications have been reported to improve flap viability and to solve a myriad of reconstructive needs. The purpose of this paper is to describe our experience in harvesting the reversed large sural flap from the proximal and middle third of the leg for large defects on the foot. We applied the extended reversed sural flap from the proximal third of the leg in traumatized patients which had large defects on their foot. The technique was done in 3 parts: 1- the flaps were designed in the proximal third of the leg five centimeter lipofascial tissue was protected around the pedicle in distal part; 3- The pivot point was located in seven to eight cm proximal the lateral malleolus before the first fasciocutaneous perforators arising from the peroneal artery. Sural flaps from the proximal and middle third of the leg were designed in13 patients who had large defects on their foot. No flap necrosis or split thickness skin graft loss occurred. The flaps healed by the 3rd week excluding two patients. This study supports the application of our technique as a safe, easy and useable method in large defects of the foot. The results showed low rates of ischemia, venous congestion, dehiscence, infection and flap necrosis. Proximal extended and large distally based sural flap is an alternative to free tissue transfer for large defect reconstruction of the foot.

  1. The use of free flaps in skull base reconstruction.

    PubMed

    Macía, G; Picón, M; Nuñez, J; Almeida, F; Alvarez, I; Acero, J

    2016-02-01

    Skull base tumours are rare, comprising less than 1% of all tumours of the head and neck. Surgical treatment of these tumours involves the approach, the resection, and the reconstruction of the defect, which present a challenge due to the technical difficulty and anatomical complexity. A retrospective study of 17 patients with tumours involving the skull base, treated by resection and immediate reconstruction using microsurgical free flaps, is presented; 11 were men and six were women. The following types of flap were used: osteocutaneous fibula flaps, fasciocutaneous anterolateral thigh flaps, and myocutaneous latissimus dorsi flaps. The most common histology of the tumours was squamous cell carcinoma. The most frequent point of origin was the paranasal sinuses (58.8%). All of the free flaps used for reconstruction were viable. A cerebrospinal fluid fistula occurred in two patients, and in one of these cases, meningoencephalitis led to death. In conclusion, the reconstruction of large defects of the skull base after ablation requires a viable tissue that in many cases can be obtained only through the use of microvascular free flaps. The type of flap to be selected depends on the anatomical structures and size of the defect to be restored.

  2. Free flap transfer for complex regional pain syndrome type II

    PubMed Central

    Matsuda, Ken; Kikuchi, Mamoru; Murase, Tsuyoshi; Hosokawa, Ko; Shibata, Minoru

    2014-01-01

    Abstract A patient with complex regional pain syndrome type II was successfully treated using free anterolateral thigh flap transfer with digital nerve coaptation to the cutaneous nerve of the flap. Release of the scarred tissue and soft tissue coverage with targeted sensory nerve coaptation were useful in relieving severe pain. PMID:27252946

  3. Tensor fascia lata musculocutaneous flap for abdominal wall reconstruction

    SciTech Connect

    Peled, I.J.; Kaplan, H.Y.; Herson, M.; Wexler, M.R.

    1983-08-01

    We report a case of abdominal wall reconstruction following excision of irradiated skin and a ventral hernia. A very large tensor fascia lata musculocutaneous flap was used with good results. The anatomical features of this flap make it an excellent method of abdominal wall reconstruction.

  4. Segmentals and Global Foreign Accent: The Japanese Flap in EFL.

    ERIC Educational Resources Information Center

    Riney, Timothy J.; Takada, Mari; Ota, Mitsuhiko

    2000-01-01

    Reports the results of research on the extent to which global foreign accent in English is related to a discrete segmental feature of pronunciation, substitution of the Japanese flap for /l/ and /r/ in two phonological environments. Results showed a strong negative correlation between a nativelike accent and flap substitution. (Author/VWL)

  5. Monitoring microvascular free flaps with tissue oxygen measurement and PET.

    PubMed

    Schrey, Aleksi R; Kinnunen, Ilpo A J; Grénman, Reidar A; Minn, Heikki R I; Aitasalo, Kalle M J

    2008-07-01

    Tissue oxygen measurement and positron emission tomography (PET) were evaluated as methods for predicting ischemia in microvascular free flaps of the head and neck. Ten patients with head and neck squamous cell cancer underwent resection of the tumour followed by microvascular reconstruction with a free flap. Tissue oxygenation of the flap (P(ti)O(2)) was continuously monitored for three postoperative (POP) days and the blood flow of the flap was assessed using oxygen-15 labelled water and PET. In three free flaps a perfusion problem was suspected due to a remarkable drop in P(ti)O(2)-values, due to two anastomosis problems and due to POP turgor. No flap losses occurred. During the blood flow measurements with PET [mean 8.5 mL 100 g(-1) min(-1 )(SD 2.5)], the mean P(ti)O(2) of the flaps [46.8 mmHg (SD 17.0)] appeared to correlate with each other in each patient (p<0.05, n=10). Tissue oxygenation measurement is a feasible monitoring system of free flaps. The perfusion-study with PET correlates with P(ti)O(2)-measurement.

  6. Active Flap Control of the SMART Rotor for Vibration Reduction

    NASA Technical Reports Server (NTRS)

    Hall, Steven R.; Anand, R. Vaidyanathan; Straub, Friedrich K.; Lau, Benton H.

    2009-01-01

    Active control methodologies were applied to a full-scale active flap rotor obtained during a joint Boeing/ DARPA/NASA/Army test in the Air Force National Full-Scale Aerodynamic Complex 40- by 80-foot anechoic wind tunnel. The active flap rotor is a full-scale MD 900 helicopter main rotor with each of its five blades modified to include an on-blade piezoelectric actuator-driven flap with a span of 18% of radius, 25% of chord, and located at 83% radius. Vibration control demonstrated the potential of active flaps for effective control of vibratory loads, especially normal force loads. Active control of normal force vibratory loads using active flaps and a continuous-time higher harmonic control algorithm was very effective, reducing harmonic (1-5P) normal force vibratory loads by 95% in both cruise and approach conditions. Control of vibratory roll and pitch moments was also demonstrated, although moment control was less effective than normal force control. Finally, active control was used to precisely control blade flap position for correlation with pretest predictions of rotor aeroacoustics. Flap displacements were commanded to follow specific harmonic profiles of 2 deg or more in amplitude, and the flap deflection errors obtained were less than 0.2 deg r.m.s.

  7. Finger pulp reconstruction with free flaps from the upper extremity.

    PubMed

    Yan, Hede; Fan, Cunyi; Gao, Weiyang; Chen, Zenggan; Li, Zhejie; Chi, Zhenglin

    2012-07-01

    Although never exceeding a few square centimeters, finger pulp defects are reconstructive challenges due to their special requirements and lack of neighboring tissue reserve. Local flaps are the common choice in the management of this injury. However, the development of microsurgery and clinical practice have greatly boosted the application of different free flaps for finger pulp reconstruction with excellent results, especially when local flaps are unsuitable or impossible for the coverage of large pulp defects. These flaps are all located in the same operation field and can be performed under one tourniquet; therefore, they are more convenient with better patients' compliance in clinical setting. Nonetheless, there is still no consensus about which type of these flaps should be preferred among various finger pulp reconstructive options. In this article, we attempt to review articles describing finger pulp reconstruction using free flaps from the upper extremity from the literature. We summarize the clinical applications of these free flaps and detail their advantages and drawbacks, respectively. The algorithm of flap selection for finger pulp reconstruction based on our experience and literature review is also discussed.

  8. Reverse sural flap for ankle and heel soft tissues reconstruction

    PubMed Central

    Ciofu, RN; Zamfirescu, DG; Popescu, SA; Lascar, I

    2017-01-01

    Introduction: The potential of the medial calf integument, as donor site for a free flap based on musculocutaneous branches of the medial sural artery, was first identified by Taylor and Daniel, following cadaver investigation. In 1981, Pontén described the fasciocutaneous sural flap as a reconstructive option for soft tissue loss of the lower extremity, particularly around the knee. Two years later, Donski and Fogdestram presented the distally based fasciocutaneous flap from the sural region followed by Montegut and Allen who considered the sural artery perforator flap as a viable alternative for the gastrocnemius myocutaneous flap. The sural flap proved a considerable versatility at the level of the lower leg (from the knee to the ankle and heel) as well as for other anatomical regions. The most common usage of the flap is for the distal-third defects of the leg. Materials and method: A group of 10 patients with soft tissue losses at the ankle or heal due to a various etiopathogeny represented by cancer excision, trauma, unstable scars, chronic osteomyelitis, in which a microsurgical free transfer had no indication or was not wanted, was presented. Our group reported a 30% complication rate in a high-risk patient population, including patients with diabetes mellitus, peripheral vascular disease, and venous insufficiency. Results: All the defects were covered successfully, without major complications. Usually, only a minor margin of the tip of the flap was lost, which was easily solved with a guided secondary healing. Most flaps showed a slight venous congestion, which cleared in a few days. The functional result was very good in all the patients, while the aesthetic appearance was acceptable even in female patients. Discussion: An ideal indication of a reverse sural flap may be a defect over an intact but partially exposed Achilles tendon. Conclusions: The sural reverse flap is useful in the ankle and foot soft tissues reconstruction whenever we have reasons not

  9. Dynamics of an Active-Site Flap Contributes to Catalysis in a JAMM Family Metallo Deubiquitinase.

    PubMed

    Bueno, Amy N; Shrestha, Rashmi K; Ronau, Judith A; Babar, Aditya; Sheedlo, Michael J; Fuchs, Julian E; Paul, Lake N; Das, Chittaranjan

    2015-10-06

    The endosome-associated deubiquitinase (DUB) AMSH is a member of the JAMM family of zinc-dependent metallo isopeptidases with high selectivity for Lys63-linked polyubiquitin chains, which play a key role in endosomal-lysosomal sorting of activated cell surface receptors. The catalytic domain of the enzyme features a flexible flap near the active site that opens and closes during its catalytic cycle. Structural analysis of its homologues, AMSH-LP (AMSH-like protein) and the fission yeast counterpart, Sst2, suggests that a conserved Phe residue in the flap may be critical for substrate binding and/or catalysis. To gain insight into the contribution of this flap in substrate recognition and catalysis, we generated mutants of Sst2 and characterized them using a combination of enzyme kinetics, X-ray crystallography, molecular dynamics simulations, and isothermal titration calorimetry (ITC). Our analysis shows that the Phe residue in the flap contributes key interactions during the rate-limiting step but not to substrate binding, since mutants of Phe403 exhibit a defect only in kcat but not in KM. Moreover, ITC studies show Phe403 mutants have similar KD for ubiquitin compared to the wild-type enzyme. The X-ray structures of both Phe403Ala and the Phe403Trp, in both the free and ubiquitin bound form, reveal no appreciable structural change that might impair substrate or alter product binding. We observed that the side chain of the Trp residue is oriented identically with respect to the isopeptide moiety of the substrate as the Phe residue in the wild-type enzyme, so the loss of activity seen in this mutant cannot be explained by the absence of a group with the ability to provide van der Waals interactions that facilitate the hyrdolysis of the Lys63-linked diubiquitin. Molecular dynamics simulations indicate that the flap in the Trp mutant is quite flexible, allowing almost free rotation of the indole side chain. Therefore, it is possible that these different dynamic

  10. Foot reconstruction using a serratus anterior muscle flap from the same donor site after failure of a thoracodorsal artery perforator flap.

    PubMed

    Kim, Sang Wha; Kwon, Young Hun; Kim, Jeong Tae; Kim, Youn Hwan

    2014-02-01

    The free flap failure rate for the lower extremities is high, which adversely affects limb salvage efforts. In this article, we report a case of failure of a thoracodorsal artery perforator flap, which was simultaneously reconstructed with a serratus anterior muscle flap from the same donor site. A 56-year-old male patient had infected wound for 3 months due to Achilles tendon rupture. We reconstructed the defect using a thoracodorsal artery perforator flap. However, 2 days after the operation, we found the congested flap. We were obliged to discard the whole flap and harvested a serratus anterior muscle flap from the same donor site. The patient's foot healed uneventfully. After flap failure, the use of a second free flap from the same donor site may be an effective and safe procedure in specific cases.

  11. Distally based perforator sural flaps for foot and ankle reconstruction

    PubMed Central

    Chang, Shi-Min; Li, Xiao-Hua; Gu, Yu-Dong

    2015-01-01

    Distally based perforator sural flaps from the posterolateral or posteromedial lower leg aspect are initially a neurofasciocutaneous flap that can be transferred reversely to the foot and ankle region with no need to harvest and sacrifice the deep major artery. These flaps are supplied by a perforating artery issued from the deep peroneal artery or the posterior tibial artery, and the chain-linked adipofascial neurovascular axis around the sural/saphenous nerve. It is a versatile and reliable technique for soft-tissue reconstruction of the heel and ankle region with 180-degrees rotation. In this paper, we present its developing history, vascular basis, surgical techniques including flap design and elevation, flap variations in pedicle and component, surgical indications, and illustrative case reports with different perforating vessels as pivot points for foot and ankle coverage. PMID:25893175

  12. Osteocutaneous radial forearm free flap in subtotal nasal reconstruction

    PubMed Central

    Moore, Alexander Michael; Montgomery, Jenny; McMahon, Jeremy; Sheikh, Saghir

    2014-01-01

    A 66-year-old man presented with a large squamous cell carcinoma of the right nasal vestibule. He underwent partial rhinectomy and medial maxillectomy followed by staged reconstruction. Reconstruction of a full-thickness nasal defect requires repair of three distinct layers: the skin–soft tissue envelope, subsurface framework and intranasal lining. We report the first use in the UK of an osteocutaneous radial forearm free flap in the reconstruction of a subtotal nasal deficit. The skin of the radial forearm free flap was tubed to recreate the nasal lining and the radial bone reconstructed the dorsal contour of the nose. A full-thickness paramedian forehead flap supplied external coverage. The osteocutaneous radial forearm free flap and forehead flap is a viable option for large nasal defects requiring reconstruction of framework, nasal lining and external covering. PMID:25427933

  13. Coarse-grained models for interacting, flapping swimmers

    NASA Astrophysics Data System (ADS)

    Oza, Anand; Ristroph, Leif; Shelley, Michael; Courant Institute Applied Math Lab Collaboration

    2016-11-01

    We present the results of a theoretical investigation into the dynamics of interacting flapping swimmers. Our study is motivated by ongoing experiments in the NYU Applied Math Lab, in which freely-translating, heaving airfoils interact hydrodynamically to choose their relative positions and velocities. We develop a discrete dynamical system in which flapping swimmers shed point vortices during each flapping cycle, which in turn exert forces on the swimmers. We present a framework for finding exact solutions to the evolution equations and for assessing their stability, giving physical insight into the preference for certain observed "schooling states". The model may be extended to arrays of flapping swimmers, and configurations in which the swimmers' flapping frequencies are incommensurate. Generally, our results indicate how hydrodynamics may mediate schooling and flocking behavior in biological contexts. A. Oza acknowledges the support of the NSF Mathematical Sciences Postdoctoral Fellowship.

  14. A method for calculating externally blown flap noise

    NASA Technical Reports Server (NTRS)

    Fink, M. R.

    1978-01-01

    Several basic noise components were described. These components are: (1) compact lift dipoles associated with the wing and flaps; (2) trailing edge noise associated with the last trailing edge; and (3) quadrupole noise associated with the undeflected exhaust jet and the free jet located downstream of the trailing edge. These noise components were combined to allow prediction of directivity and spectra for under the wing (UTW) slotted flaps with conventional or mixer nozzles, UTW slotless flaps, upper surface blowing (USB) slotless flaps, and engine in front of the wing slotted flaps. A digital computer program listing was given for this calculation method. Directivities and spectra calculated by this method were compared with free field data for UTW and USB configurations. The UTRC method best predicted the details of the measured noise emission, but the ANOP method best estimated the noise levels directly below these configurations.

  15. Free Flap Procedures for Reconstruction After Head and Neck Cancer.

    PubMed

    Kini, Erin

    2015-12-01

    Patients with head and neck cancer are seeking improved surgical procedures to avoid severe defects that result from head and neck cancer resection. Free flap reconstruction provides vascularized tissue that has been transferred from a distant donor site on a patient's body to a recipient site, markedly improving wound closure and protecting structures of the head and neck. This article discusses free flap procedures for reconstruction after head and neck cancer resection, including the following procedure phases: airway protection and neck dissections, tumor resection, flap harvest, microvascular anastomosis of the flap, and reconstruction and closure. The article also explains specific risk factors for patients undergoing free flap procedures that have been identified in the literature and include procedure length, hypothermia, and pressure injuries. Each of these factors is discussed regarding its specific effect on this patient population, and the nursing interventions to reduce these risks are identified.

  16. Works on theory of flapping wing. [considering boundary layer

    NASA Technical Reports Server (NTRS)

    Golubev, V. V.

    1980-01-01

    It is shown mathematically that taking account of the boundary layer is the only way to develop a theory of flapping wings without violating the basic observations and mathematics of hydromechanics. A theory of thrust generation by flapping wings can be developed if the conventional downstream velocity discontinuity surface is replaced with the observed Karman type vortex streets behind a flapping wing. Experiments show that the direction of such vortices is the reverse of that of conventional Karman streets. The streets form by breakdown of the boundary layer. Detailed analysis of the movements of certain birds and insects during flight 'in place' is fully consistent with this theory of the lift, thrust and drag of flapping wings. Further directions for research into flight with flapping wings are indicated.

  17. Reconstruction of weightbearing forefoot defects with digital artery flaps.

    PubMed

    Liu, Lifeng; Cao, Xuecheng; Cai, Jinfang

    2015-01-01

    Reconstruction of a defect of the weightbearing forefoot region remains a challenging problem owing to the limited alternatives available. The digital artery flap can be used for coverage of defects in the weightbearing forefoot. The present study reports our results using a digital artery flap for reconstruction of soft tissue defects of the weightbearing forefoot in 8 patients. The mean patient age was 35 ± 11.3 years. The etiology of the soft tissue defects included 4 (50%) traumatic events, 2 (25%) dysfunctional scars, and 2 (25%) neuropathic ulcerations. The mean postoperative follow-up duration was 22 ± 11.1 months (range 12 months to 4 years). All 8 flaps survived successfully. The complications included 1 case of delayed healing of a neuropathic ulceration. The digital artery flap is a good alternative for soft tissue defects of the weightbearing forefoot. The surgical techniques for harvesting the flaps are easy to manage.

  18. Distally Based Abductor Hallucis Adipomuscular Flap for Forefoot Plantar Reconstruction.

    PubMed

    Lee, Sanglim; Kim, Min Bom; Lee, Young Ho; Baek, Jeong Kook; Baek, Goo Hyun

    2015-09-01

    Soft tissue and bone defects of the lower leg, ankle, and heel region often require coverage by local or distant flaps. The authors successfully used the distally based adipomuscular abductor hallucis flap for the treatment of 7 patients with soft tissue defect on the plantar forefoot after diabetic ulcer (n = 2), excision of melanoma at the medial forefoot (n = 3), and posttraumatic defects of the plantar forefoot (n = 2). The size of the defects ranged from 6 to 36 cm. All defects were covered successfully without major complications. The distally based adipomuscular flap from the abductor hallucis muscle provides a reliable coverage for small and moderate defects of the plantar and medial forefoot. This flap is often preferable to the use of free flaps because the surgery is rapidly performed and does not require microsurgical expertise.

  19. Experimental investigation of a flapping wing model

    NASA Astrophysics Data System (ADS)

    Hubel, Tatjana Y.; Tropea, Cameron

    2009-05-01

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  20. Experimental investigation of a flapping wing model

    NASA Astrophysics Data System (ADS)

    Hubel, Tatjana Y.; Tropea, Cameron

    The main objective of this research study was to investigate the aerodynamic forces of an avian flapping wing model system. The model size and the flow conditions were chosen to approximate the flight of a goose. Direct force measurements, using a three-component balance, and PIV flow field measurements parallel and perpendicular to the oncoming flow, were performed in a wind tunnel at Reynolds numbers between 28,000 and 141,000 (3-15 m/s), throughout a range of reduced frequencies between 0.04 and 0.20. The appropriateness of quasi-steady assumptions used to compare 2D, time-averaged particle image velocimetry (PIV) measurements in the wake with direct force measurements was evaluated. The vertical force coefficient for flapping wings was typically significantly higher than the maximum coefficient of the fixed wing, implying the influence of unsteady effects, such as delayed stall, even at low reduced frequencies. This puts the validity of the quasi-steady assumption into question. The (local) change in circulation over the wing beat cycle and the circulation distribution along the wingspan were obtained from the measurements in the tip and transverse vortex planes. Flow separation could be observed in the distribution of the circulation, and while the circulation derived from the wake measurements failed to agree exactly with the absolute value of the circulation, the change in circulation over the wing beat cycle was in excellent agreement for low and moderate reduced frequencies. The comparison between the PIV measurements in the two perpendicular planes and the direct force balance measurements, show that within certain limitations the wake visualization is a powerful tool to gain insight into force generation and the flow behavior on flapping wings over the wing beat cycle.

  1. Infrahyoid myofascial flap for tongue reconstruction.

    PubMed

    Windfuhr, Jochen P; Remmert, Stephan

    2006-11-01

    For selected cases, reconstruction of the tongue may be required after tumor removal. This study was undertaken to demonstrate a simplified concept of tongue reconstruction with emphasis on infrahyoid myofascial flaps (IMF). The defects of the tongue were classified in 23 patients according to the extent of tumor growth, functional and surgical aspects. The oral tongue (OT; n = 1), base of tongue (BT; n = 12) or both areas (OT and BT; n = 10) were involved, with (n = 14) or without (n = 9) infiltration of adjacent tissues. Minor defects (extent (1/4) or less) required no reconstructive procedure at any area. Major defect closure (extent (1/2)-3/4) was accomplished with a combination of IMF covered by a radial forearm flap (RFF). A complete reconstruction of the OT was achieved with a combination of a bilateral IMF covered by a RFF. Whenever the complete BT has to be removed, interposition of a vein graft to establish a sufficient arterial blood supply to the remaining OT is mandatory. Moreover, a larynx lift to prevent aspiration is recommendable. Resection of adjacent soft tissues requires a larger RFF (OT; BT) or flaps from the shoulder-back region (BT and OT). Whenever the integrity of the mandible has to be sacrificed, a free fibula graft serves as an excellent tool for reconstruction. IMF serves as a reliable tool for minor or major reconstructive procedures of the tongue. Reliability and versatility of IMF may contribute to a reduced time required for surgery since harvesting is performed in the neck area immediately after neck dissection. Moreover, harvesting of the IMF does not result in an increased postoperative morbidity. Hence, functional restoration can be achieved with a more cost-effective procedure.

  2. Pectoralis Major Myocutaneous Flap for Head and Neck Defects in the Era of Free Flaps: Harvesting Technique and Indications

    PubMed Central

    Liu, Muyuan; Liu, Weiwei; Yang, Xihong; Guo, Haipeng; Peng, Hanwei

    2017-01-01

    The role of the pectoralis major myocutaneous flap (PMMF) in head and neck reconstruction is challenged recently due to its natural drawbacks and the popularity of free flaps. This study was designed to evaluate the indications and reliability of using a PMMF in the current free flap era based on a single center experience. The PMMF was harvested as a pedicle-skeletonized flap, with its skin paddle caudally and medially to the areola, including the third intercostal perforator, preserving the upper one third of the pectoralis major muscle. The harvested flap was passed via a submuscular tunnel over the clavicle. One hundred eighteen PMMFs were used in 114 patients, of which 76 were high-risk candidates for a free flap; 8 patients underwent total glossectomy, and 30 underwent salvage or emergency reconstruction. Major complications occurred in 4 patients and minor complications developed in 10. Tracheal extubation was possible in all cases, while oral intake was possible in all but 1 case. These techniques used in harvesting a PMMF significantly overcome its natural pitfalls. PMMFs can safely be used in head and neck cancer patients who need salvage reconstruction, who are high risk for free flaps, and who need large volume soft-tissue flaps. PMID:28387356

  3. Pectoralis Major Myocutaneous Flap for Head and Neck Defects in the Era of Free Flaps: Harvesting Technique and Indications.

    PubMed

    Liu, Muyuan; Liu, Weiwei; Yang, Xihong; Guo, Haipeng; Peng, Hanwei

    2017-04-07

    The role of the pectoralis major myocutaneous flap (PMMF) in head and neck reconstruction is challenged recently due to its natural drawbacks and the popularity of free flaps. This study was designed to evaluate the indications and reliability of using a PMMF in the current free flap era based on a single center experience. The PMMF was harvested as a pedicle-skeletonized flap, with its skin paddle caudally and medially to the areola, including the third intercostal perforator, preserving the upper one third of the pectoralis major muscle. The harvested flap was passed via a submuscular tunnel over the clavicle. One hundred eighteen PMMFs were used in 114 patients, of which 76 were high-risk candidates for a free flap; 8 patients underwent total glossectomy, and 30 underwent salvage or emergency reconstruction. Major complications occurred in 4 patients and minor complications developed in 10. Tracheal extubation was possible in all cases, while oral intake was possible in all but 1 case. These techniques used in harvesting a PMMF significantly overcome its natural pitfalls. PMMFs can safely be used in head and neck cancer patients who need salvage reconstruction, who are high risk for free flaps, and who need large volume soft-tissue flaps.

  4. The scapular, parascapular, and latissimus dorsi flap as a single osteomyocutaneous flap for repair of complex oral defects.

    PubMed

    Janus, Jeffrey R; Carlson, Matthew L; Moore, Eric J

    2012-01-01

    Complex composite defects of the oral cavity are often created due to en bloc resection of malignant tumors. These defects can involve bone, soft tissue, oral mucosa, and external skin, posing a reconstructive challenge to the microvascular surgeon. Though advances have been made in free tissue transfer via piggybacking techniques and double free-flaps, increases in operative time and morbidity remain limiting factors. Likewise, advancements in single composite flaps (e.g., double-skin paddle fibular free-flap) allow for a single donor site, but limit workable tissue. This report describes our experience with the scapular, parascapular, and latissimus dorsi (SPLD) as a combined single unit osteomyocutaneous flap for composite reconstruction of complex oral defects. A case example is subsequently reviewed for clinical correlation. This is an operative techniques article describing the use of the SPLD single multi-tissue flap for repair of complex oral defects. Cadaveric dissection was performed for instructional purposes. Case example was given for clinical correlation. Relevant history, anatomy, procedural details, and possible complications are presented and subsequently correlated to the case example. A SPLD free-flap as a single multi-tissue flap is a viable and beneficial option for reconstruction of complex oral defects. It provides the volume of tissue necessary to fill composite defects and exists as an alternative to multi-flap procedures, which carry a longer operative time and multiple donor site morbidity.

  5. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 50 Wildlife and Fisheries 10 2012-10-01 2012-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS...

  6. 50 CFR Figure 16 to Part 223 - Escape Opening and Flap Dimensions for the Double Cover Flap TED

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 50 Wildlife and Fisheries 9 2011-10-01 2011-10-01 false Escape Opening and Flap Dimensions for the Double Cover Flap TED 16 Figure 16 to Part 223 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE, NATIONAL OCEANIC AND ATMOSPHERIC ADMINISTRATION, DEPARTMENT OF COMMERCE MARINE MAMMALS THREATENED...

  7. Aerodynamics of the upper surface blow flap

    NASA Technical Reports Server (NTRS)

    Phelps, A. E., III

    1972-01-01

    The results of some preliminary wind-tunnel investigations made to provide fundamental aerodynamic information on the upper surface blown jet-flap concept incorporating high-bypass-ratio turbofan engines are summarized. The results of the investigation have shown the concept to have aerodynamic performance generally similar to that of other externally blown high-lift systems. A few of the more critical problems associated with this concept have been identified and preliminary solutions to some of these problems have been found. These results have proven to be sufficiently encouraging to warrant continuation of fundamental research efforts on the concept.

  8. Vortex induced lift on a flat plate with a curved forward-facing flap

    NASA Technical Reports Server (NTRS)

    Tanveer, S.

    1985-01-01

    Free streamline solutions are obtained for two-dimensional inviscid incompressible flow past a flat plate with a forward-facing curved flap. It is shown that it is possible to shape the curved flap to make the adverse pressure gradient on top of the flap less severe than for a straight flap and thus increase the prospects of making the flow experimentally realizable.

  9. Free medial thigh perforator-based flaps: new definition of the pedicle vessels and versatile application.

    PubMed

    Koshima, I; Hosoda, M; Inagawa, K; Moriguchi, T; Orita, Y

    1996-11-01

    The medial thigh flap is a perforator-based flap nourished with septocutaneous or muscle perforators originating from the femoral vessels. To date, 8 patients have been repaired with this flap and extended or connected flaps including this flap: 4 patients with lower leg defects and 4 patients with intraoral and neck defects. The advantages of this flap are (1) several pedicle perforators exist for this flap, which makes possible duplicated vascular anastomoses to establish reliable circulation of the transferred flap; (2) the flap can be extended or connected to other neighboring flaps in the anterior thigh, so that extensively wide defects can be closed in one stage; (3) the great saphenous vein can be simultaneously used as a vein graft or for venous drainage for the flap; (4) the anterior branch of the femoral nerve can be used for sensory potential; and (5) there is minimum morbidity of the donor defect and a large dominant vessel for the leg can be preserved. The suitable indications for this flap are defects after removal of skin cancer in the foot or lower leg and wide defects after resection of head and neck cancer, which can be reconstructed with the flap connected to neighboring skin flaps. The disadvantages of this flap are that it has a small, short vascular pedicle and the bulkiness of the flap's fatty tissue often requires thinning.

  10. 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.

  11. Flap prefabrication and stem cell-assisted tissue expansion: how we acquire a monoblock flap for full face resurfacing.

    PubMed

    Li, Qingfeng; Zan, Tao; Li, Haizhou; Zhou, Shuangbai; Gu, Bin; Liu, Kai; Xie, Feng; Xie, Yun

    2014-01-01

    Total face skin and soft-tissue defects remain one of the biggest challenges in reconstructive surgery. Reconstruction of the entire face with uniform coverage and delicate features is difficult to achieve. To avoid the patchwork result seen in multiple flaps and skin grafts, 1 monoblock flap that has similar color, texture, and thickness might be an ideal option to minimize the incisional scars and several surgical procedures but is unavailable with current approaches because of the lack of sufficient matched tissue and the unreliable blood supply for such a large flap. To acquire a monoblock flap for full face reconstruction, we combine the prefabricated flaps, skin overexpansion, and bone marrow mononuclear stem cell transplantation for total facial resurfacing. In this article, we present our experience from our case series that provides universally matched skin and near-normal facial contour. It is a reliable and an excellent reconstructive option for massive facial skin defect.

  12. Structural insights into 5' flap DNA unwinding and incision by the human FAN1 dimer.

    PubMed

    Zhao, Qi; Xue, Xiaoyu; Longerich, Simonne; Sung, Patrick; Xiong, Yong

    2014-12-11

    Human FANCD2-associated nuclease 1 (FAN1) is a DNA structure-specific nuclease involved in the processing of DNA interstrand crosslinks (ICLs). FAN1 maintains genomic stability and prevents tissue decline in multiple organs, yet it confers ICL-induced anti-cancer drug resistance in several cancer subtypes. Here we report three crystal structures of human FAN1 in complex with a 5' flap DNA substrate, showing that two FAN1 molecules form a head-to-tail dimer to locate the lesion, orient the DNA and unwind a 5' flap for subsequent incision. Biochemical experiments further validate our model for FAN1 action, as structure-informed mutations that disrupt protein dimerization, substrate orientation or flap unwinding impair the structure-specific nuclease activity. Our work elucidates essential aspects of FAN1-DNA lesion recognition and a unique mechanism of incision. These structural insights shed light on the cellular mechanisms underlying organ degeneration protection and cancer drug resistance mediated by FAN1.

  13. Structural insights into 5‧ flap DNA unwinding and incision by the human FAN1 dimer

    NASA Astrophysics Data System (ADS)

    Zhao, Qi; Xue, Xiaoyu; Longerich, Simonne; Sung, Patrick; Xiong, Yong

    2014-12-01

    Human FANCD2-associated nuclease 1 (FAN1) is a DNA structure-specific nuclease involved in the processing of DNA interstrand crosslinks (ICLs). FAN1 maintains genomic stability and prevents tissue decline in multiple organs, yet it confers ICL-induced anti-cancer drug resistance in several cancer subtypes. Here we report three crystal structures of human FAN1 in complex with a 5‧ flap DNA substrate, showing that two FAN1 molecules form a head-to-tail dimer to locate the lesion, orient the DNA and unwind a 5‧ flap for subsequent incision. Biochemical experiments further validate our model for FAN1 action, as structure-informed mutations that disrupt protein dimerization, substrate orientation or flap unwinding impair the structure-specific nuclease activity. Our work elucidates essential aspects of FAN1-DNA lesion recognition and a unique mechanism of incision. These structural insights shed light on the cellular mechanisms underlying organ degeneration protection and cancer drug resistance mediated by FAN1.

  14. Aeroacoustic Measurements of a Wing-Flap Configuration

    NASA Technical Reports Server (NTRS)

    Meadows, Kristine R.; Brooks, Thomas F.; Humphreys, William M.; Hunter, William H.; Gerhold, Carl H.

    1997-01-01

    Aeroacoustic measurements are being conducted to investigate the mechanisms of sound generation in high-lift wing configurations, and initial results are presented. The model is approximately 6 percent of a full scale configuration, and consists of a main element NACA 63(sub 2) - 215 wing section and a 30 percent chord half-span flap. Flow speeds up to Mach 0.17 are tested at Reynolds number up to approximately 1.7 million. Results are presented for a main element at a 16 degree angle of attack, and flap deflection angles of 29 and 39 degrees. The measurement systems developed for this test include two directional arrays used to localize and characterize the noise sources, and an array of unsteady surface pressure transducers used to characterize wave number spectra and correlate with acoustic measurements. Sound source localization maps show that locally dominant noise sources exist on the flap-side edge. The spectral distribution of the noise sources along the flap-side edge shows a decrease in frequency of the locally dominant noise source with increasing distance downstream of the flap leading edge. Spectra are presented which show general spectral characteristics of Strouhal dependent flow-surface interaction noise. However, the appearance of multiple broadband tonal features at high frequency indicates the presence of aeroacoustic phenomenon following different scaling characteristics. The scaling of the high frequency aeroacoustic phenomenon is found to be different for the two flap deflection angles tested. Unsteady surface pressure measurements in the vicinity of the flap edge show high coherence levels between adjacent sensors on the flap-side edge and on the flap edge upper surface in a region which corresponds closely to where the flap-side edge vortex begins to spill over to the flap upper surface. The frequency ranges where these high levels of coherence occur on the flap surface are consistent with the frequency ranges in which dominant features

  15. Free Medial Plantar Flap Connection with a Posterior Tibial Artery Flap in Reconstruction of Fore–Mid Foot Skin Defect

    PubMed Central

    Wu, Hao; Sheng, Jia-Gen

    2016-01-01

    Background: Although there are many surgical treatments for covering the skin defect of the fore–mid foot, how to reconstruct the weight-bearing region remains a challenge. The weight-bearing region of the sole needs to withstand the pressure and shearing stresses of walking, so the plantar skin is anatomically different from other skins in the areas of texture, thickness, subcutaneous tissue, etc. Medial plantar flaps that are harvested from the instep region are regarded as the first choice for weight-bearing region reconstruction because of their excellent functional and aesthetic long-term result. However, when facing an extensive skin defect on a weight-bearing area such as a fore–mid foot avulsion, the application of this flap is limited because if we put the flap in a weight-bearing area of the forefoot, the set of vessels will be exposed to outside. Methods: We suggest 2 connected free flaps (posterior tibial artery flap and medial plantar flap) pedicled with 1 set of vessels. The medial plantar flap was used to cover the skin defect of the weight-bearing area in the forefoot. The dorsal skin defect of the injured foot was covered with a posterior tibial artery flap and supplied the medial plantar flap with the posterior tibial vessel. The midfoot skin defect was repaired by a full-skin grafting. Results: Long-term follow-up results showed that the shape and function of the injured limbs recovered almost entirely. Conclusion: This method of connected flaps is suitable for repairing large skin defects of the fore–mid foot. PMID:27975013

  16. Syndactyly correction using a venous flap with the plantar cutaneous venous arch.

    PubMed

    Sakamoto, Natsuki; Matsumura, Hajime; Komiya, Takako; Imai, Ryutaro; Niyaz, Ahmatjan; Watanabe, Katsueki

    2014-01-01

    A combination of skin grafts and local flaps is widely used in the reconstruction of syndactyly of the toes. Covering the skin defect without skin grafts on the unilateral side of the toe is preferred, and for this purpose, a rotated flap from the plantar area is typically used. However, the flap can become ischemic or congested in some cases. To avoid this, we elevated a plantar flap with the plantar cutaneous venous arch using a triangular venous flap and covered the lateral side of the web in 7 cases of syndactyly. The dorsal flap was used to create the new web, and the opposite lateral side was reconstructed using a skin graft. The flap circulation was stable, the pedicle of the flap was narrow, and the flap relocation was simple. No flap in any patient showed any evidence of congestion or ischemia. Follow-up demonstrated that the new web was patent in all cases, with no evidence of contraction.

  17. Uncertainty Analysis for a Jet Flap Airfoil

    NASA Technical Reports Server (NTRS)

    Green, Lawrence L.; Cruz, Josue

    2006-01-01

    An analysis of variance (ANOVA) study was performed to quantify the potential uncertainties of lift and pitching moment coefficient calculations from a computational fluid dynamics code, relative to an experiment, for a jet flap airfoil configuration. Uncertainties due to a number of factors including grid density, angle of attack and jet flap blowing coefficient were examined. The ANOVA software produced a numerical model of the input coefficient data, as functions of the selected factors, to a user-specified order (linear, 2-factor interference, quadratic, or cubic). Residuals between the model and actual data were also produced at each of the input conditions, and uncertainty confidence intervals (in the form of Least Significant Differences or LSD) for experimental, computational, and combined experimental / computational data sets were computed. The LSD bars indicate the smallest resolvable differences in the functional values (lift or pitching moment coefficient) attributable solely to changes in independent variable, given just the input data points from selected data sets. The software also provided a collection of diagnostics which evaluate the suitability of the input data set for use within the ANOVA process, and which examine the behavior of the resultant data, possibly suggesting transformations which should be applied to the data to reduce the LSD. The results illustrate some of the key features of, and results from, the uncertainty analysis studies, including the use of both numerical (continuous) and categorical (discrete) factors, the effects of the number and range of the input data points, and the effects of the number of factors considered simultaneously.

  18. Flapping propulsion with tip pitch control

    NASA Astrophysics Data System (ADS)

    Huera-Huarte, Francisco; Gharib, Morteza

    2014-11-01

    The effect of flexibility in the propulsion performance and efficiency of oscillating pitching foils has received a large amount of attention in the past years. Scientists have used simplified robotic models that mimic the kinematics of flying and swimming animals, in order to get inspiration to build more efficient engineering systems. Compliance is one of the aspects that has received more attention, as it seems to be a common feature in nature's flyers and swimmers. Active or passive control elements are also common in nature. We will show how thrust generation in a pitching fin, can be greatly affected by controlling the tip pitch motion dynamically and independently of the fin itself. This is in fact a controlled local change of curvature of the end of the fin. A robotic system has been designed in a way that not only flapping amplitudes and frequencies can be controlled, but also the amplitudes and frequencies of the tip and the phase difference between the tip and the fin. We measured thrust forces and the vortex dynamics in the near wake of the system, by using planar DPIV (Digital Particle Image Velocimetry) in a wide variety of flapping situations with tip control. Funding from Spanish Ministry of Science through Grant DPI2012-37904 is gratefully acknowledged.

  19. Modeling flexible flapping wings oscillating at resonance

    NASA Astrophysics Data System (ADS)

    Alexeev, Alexander; Masoud, Hassan

    2010-03-01

    Using a hybrid approach for fluid-structure interactions that integrates the lattice Boltzmann and lattice spring models, we study the three-dimensional aerodynamics of flexible flapping wings at hovering. The wings are a pair of flat elastic plates tilted from the horizontal and driven to oscillate according to the sinusoidal law. Our simulations reveal that resonance oscillations of flexible wings dramatically increase aerodynamic lift at low Reynolds number. Comparing to otherwise identical rigid wings, flexible wings at resonance generate up to two orders of magnitude greater lift. Within the resonance band, we identify two operation regimes leading to the maximum lift and the maximum efficiency, respectively. The maximum lift occurs when the wing tip and root move with a phase lag of 90 degrees, whereas the maximum efficiency occurs at the frequency where the wing tip and root oscillate in counterphase. Our results suggest that the resonance regimes would be optimal for the design of microscale flying machines using flexible flapping wings driven by simple kinematic strokes.

  20. Multidisciplinary CFD/CSD Analysis of the Smart Active Flap Rotor

    DTIC Science & Technology

    2010-05-01

    control (Ref. 20). SMART rotor instrumentation includes flap bending, chord bending, and torsion moments at several radial stations on the blade; pitch link...modeled using a lifting-line model and airfoil table look- up , with 20 aerodynamic panels. A tip loss correction is not used. Flap aerodynamic...using the fine grid. The portion of the blade without the flap is made up of 8 grids (root cap, pitchcase, inboard of the flap , flap region, outboard of

  1. Droplet ejection and sliding on a flapping film

    NASA Astrophysics Data System (ADS)

    Chen, Xi; Doughramaji, Nicole; Betz, Amy Rachel; Derby, Melanie M.

    2017-03-01

    Water recovery and subsequent reuse are required for human consumption as well as industrial, and agriculture applications. Moist air streams, such as cooling tower plumes and fog, represent opportunities for water harvesting. In this work, we investigate a flapping mechanism to increase droplet shedding on thin, hydrophobic films for two vibrational cases (e.g., ± 9 mm and 11 Hz; ± 2 mm and 100 Hz). Two main mechanisms removed water droplets from the flapping film: vibrational-induced coalescence/sliding and droplet ejection from the surface. Vibrations mobilized droplets on the flapping film, increasing the probability of coalescence with neighboring droplets leading to faster droplet growth. Droplet departure sizes of 1-2 mm were observed for flapping films, compared to 3-4 mm on stationary films, which solely relied on gravity for droplet removal. Additionally, flapping films exhibited lower percentage area coverage by water after a few seconds. The second removal mechanism, droplet ejection was analyzed with respect to surface wave formation and inertia. Smaller droplets (e.g., 1-mm diameter) were ejected at a higher frequency which is associated with a higher acceleration. Kinetic energy of the water was the largest contributor to energy required to flap the film, and low energy inputs (i.e., 3.3 W/m2) were possible. Additionally, self-flapping films could enable novel water collection and condensation with minimal energy input.

  2. Delayed type IV muscle flap in a feline model.

    PubMed

    Snyder, Ned; Craven, Cameron; Phillips, Linda G

    2006-03-01

    The concept of delaying a skin flap is well established and has been implemented into plastic surgery practice for years. Some investigators have delayed musculocutaneous flaps to improve the perforator inflow. To our knowledge, the concept of delaying a muscle flap had previously never been tested in a model with segmental pedicles. Five cats each underwent 3 sequential operations providing them with a sartorius muscle whose blood supply was a single distal pedicle. The opposite leg was used as a control. Our delayed type IV muscle flap demonstrated perfusion to the proximal tip of the sartorius muscle without necrosis or loss of muscle mass (P < 0.0001). The control showed no evidence of perfusion beyond the distal portion of the muscle when infused through the distal pedicle. The delayed flap can survive on a distal blood supply that would not be adequate in a single-stage procedure. This flap has an increased arc of rotation that may provide solutions to difficult reconstructive problems in the groin, lower abdomen, genitalia, knee, proximal leg, and might be suitable as a free flap.

  3. Free jejunal flaps can be monitored by use of microdialysis.

    PubMed

    Sorensen, Hanne Birke

    2008-08-01

    When new combinations of preoperative treatments of carcinoma of the esophagus are implemented, surgical morbidity and mortality become even more important risk factors. This study investigated whether the risk of postoperative complications caused by ischemia in the reconstructed esophagus can be reduced using microdialysis as monitoring method. This is a retrospective study of 14 patients undergoing resection of carcinoma in the upper part of the esophagus and reconstruction with a free jejunal flap. The metabolism in all 14 jejunal transfers was monitored by use of microdialysis. The data were analyzed looking for reliable parameters detecting critical ischemia. Critical ischemia was suspected in two cases. Both of these cases were surgically revised, ischemia in the jejunal flap was verified, and the jejunal flaps were revascularized. All 14 jejunal flaps survived. Using the concentration of glucose in the microdialysate, it was possible to detect the two cases of critical ischemia. Yet, the most reliable parameter seemed to be the retrospectively calculated lactate:glucose ratio; in both the ischemic flaps, the lactate:glucose ratio exceeded more than 1000% the maximum values found in all the nonischemic flaps. Microdialysis is a promising monitoring method for surveillance of free jejunal flaps.

  4. Combination therapy for salvaging a failing, experimental skin flap.

    PubMed

    Shah, D K; Zhang, W X; Forman, D L; Prabhat, A; Urken, M L; Weinberg, H

    1996-08-01

    The failing free flap remains a major problem for the reconstructive surgeon. Many and varied pharmacologic agents have been utilized to reverse the effects of ischemia in these flaps. Treatments have been aimed at inhibiting presumed causative factors in the no-reflow phenomenon. Therapy has generally been single in nature and designed to affect only one of these presumed factors. In this study, several pharmacologic agents were utilized individually or in combination therapy as postischemic washouts, in an effort to attack the multiple causative factors in the no-reflow phenomenon and to improve flap survival in a rat abdominal skin flap model. The treatment agents included lactated Ringer's, superoxide dismutase, and urokinase, with each used independently as a postischemic perfusion washout. Combination therapy utilized an initial postischemic perfusion with urokinase, followed by a second perfusion washout with superoxide dismutase. After 18 hr of primary ischemia, there was increased flap survival in the animals undergoing perfusion washout with either superoxide dismutase alone or with combined urokinase and superoxide dismutase washouts, compared to all other treatments (p < 0.001). It was found that flaps undergoing combined urokinase and superoxide dismutase postischemic perfusion washouts demonstrated significantly improved survival after 20 hr of primary ischemia, compared to all other therapies (p < 0.05). By demonstrating improved survival when a thrombolytic agent is used in conjunction with an oxygen free radical scavenger, these findings may have implications in the treatment of clinically failing free flaps.

  5. A pedicled muscle flap based solely on a neural pedicle.

    PubMed

    Avci, Gulden; Akan, Mithat; Akoz, Tayfun; Kuzon, William; Gul, Aylin Ege

    2009-01-01

    We tested the hypothesis that the intrinsic vascular plexus of the motor nerve could support viability in a rat hindlimb muscle flap. In a preliminary study, we examined the course and vascularity of the sciatic nerve, the peroneal nerve, and the peroneous longus muscle in the rat hindlimb via anatomic dissection, microangiography, and histologic study (n = 10 animals). On the basis of this examination, the peroneous longus muscle was chosen as our experimental model in this study. In 12 animals, the peroneus longus was acutely elevated, which severed all tendinous and vascular structures, this left the muscle pedicled on the motor nerve only (Group I). Animals in Group II underwent a staged elevation of the flap with division of the vascular pedicle, the tendon of insertion, and the tendon of origin during separate procedures that were 5 days apart (n = 12). Muscle viability was evaluated by gross inspection, measurement of muscle weight and length, nitroblue tetrazlium (NBT) staining, microangiography, and histology. NBT staining demonstrated that immediate elevation of the peroneus longus muscle flaps led to an average necrotic area of 80.6% +/- 9.8% (Group I). A significant improvement in viability was observed for muscle flaps of animals in Group II, with peroneus longus muscle necrosis averaging 25.6% +/- 9.3%. Microangiography demonstrated that the intrinsic vascularity of nerve was increased dramatically in Group II. These data support the hypothesis that the intrinsic vascular plexus of the motor nerve of a skeletal muscle can support at least partial viability of a muscle flap. However, this vascular axis is inadequate to support complete viability of a muscle flap if the flap is elevated immediately. If a staged elevation affects a surgical delay, the viability of a muscle flap elevated on a neural pedicle can be increased significantly. With adjustments in the delay procedure, this strategy may allow transfer of muscle flaps when maintenance or

  6. The relative survival of composite free flaps in head and neck reconstruction.

    PubMed

    Van Genechten, M L V; Batstone, M D

    2016-02-01

    Various composite free flaps are available for reconstruction of bony head and neck defects. The aim of this study was to compare the relative success of four different bony free flaps. One hundred and seventy-three microvascular composite free flap reconstructions for bony defects of the head and neck region, performed over the period April 2008 to April 2015, were reviewed retrospectively. The type of free flap, indication for free flap reconstruction, age at harvesting of the free flap, use of pre- or postoperative radiotherapy, and free flap failure were examined. For the 173 reconstructions performed, 84 fibula free flaps, 43 iliac crest free flaps, 32 scapula free flaps, and 14 osteocutaneous radial forearm free flaps were harvested. The mean age at time of harvesting was 40.7 years for the iliac crest, 57.3 years for the fibula, 64.3 years for the scapula, and 73.9 years for the osteocutaneous radial forearm free flap. No complete free flap failure was documented, nor was there any failure of bony segments. Three fibula flap skin paddles did not survive. No returns to theatre for salvage were required. This study showed no difference in the survival rates of these four types of composite free flap.

  7. Does body mass index matter while selecting the flap type for pharyngeal reconstructions?

    PubMed

    Calli, Caglar; Teknos, Theodoros N; Agrawal, Amit; Schuller, David E; Ozer, Enver; Songu, Murat

    2014-05-01

    The aim of our study was to investigate the effect of patient-related factors, such as the body mass index (BMI) and tumor size, in selecting the flap type for the reconstruction of pharyngeal defects. This retrospective review included 182 patients with pharyngeal defect reconstructions with free and pedicled flaps at the Ohio State University from January 2005 to December 2008. We conducted a retrospective comparison of variety of different flap reconstruction techniques. We compared different flap reconstruction with BMI and tumor size without functional outcome such as swallowing and speech data. Although there was no statistically significant correlation (P > 0.05) when comparing the free flaps with pedicled flaps according to the BMI and tumor size, there was an obvious tendency to prefer radial forearm free flap over anterolateral thigh free flap in patients who are overweight and those with obesity with a ratio of 32:3. In the same group of patients, a similar tendency was observed to prefer fibular free flap over iliac crest free flap with a ratio of 14:5, whereas the ratio was becoming 3:5 in favor of iliac crest free flap over fibular free flap in patients with BMI of 24 or lower. Despite the fact that surgeons' experience with a certain flap type is one of the most important factors while determining which flap to reconstruct, BMI might have a significant impact while selecting the free flap types for the reconstruction of pharyngeal defects.

  8. Facial Artery Musculomucosal (FAMM) flap for nasal lining in reconstruction of large full thickness lateral nasal defects.

    PubMed

    Rahpeyma, Amin; Khajehahmadi, Saeedeh

    2015-12-01

    Obviously, restoring the nasal lining is a great challenge in the reconstruction of nasal defects. Full thickness nasal defects usually require special flaps for reconstructing the nasal lining. Intranasal mucosal flaps, hinge over flaps, perinasal second flaps, folded or second forehead flaps and finally free flaps are examples that can be used for this purpose. Moreover, the case presented in this article expresses a new role for the superiorly based Facial Artery Musculomucosal (FAMM) flap in this topic. Furthermore, mucosal island variant of this flap is presented to reduce the tension on this flap while restoring the nasal lining in large full thickness nasal defect.

  9. [Hueston's flap in distal digital amputations. Apropos of 43 cases].

    PubMed

    Dallassera, M; Foucher, G

    1996-06-01

    John Hueston described an advancement rotation flap, sacrificing the innervation of the advanced skin. René Souquet proposed a modification of the technique to retain the sensitivity of the advanced skin. We reviewed 43 such flaps to compare the long term results with a median follow-up of 3 years. The mean 2PD was 6.8 mm for the classical technique and 5.9 mm for the modified flaps. The Semmes-Weinstein test was identical to the controlateral side in 77% and 92% of cases, respectively. These discrepencies were not statistically significant.

  10. Surgical Excision of Multiple Penile Syringomas With Scrotal Flap Reconstruction

    PubMed Central

    Vaca, Elbert E.; Mundinger, Gerhard S.; Zelken, Jonathan A.; Erdag, Gulsun

    2014-01-01

    Objective: Penile syringomas are rare lesions usually occurring in isolation. We report the excision and reconstruction of multiple synchronous penile shaft syringomas with local scrotal flaps. Methods: We report a rare case of excision of multiple penile syringomas and reconstruction with scrotal flaps in a 29-year-old man. Results: Penile syringomas were excised and reconstructed with scrotal flaps in a single-stage procedure. Conclusions: In addition to providing wound coverage, this reconstructive option allowed for excellent functional results with regard to shaft alignment and erectile function, and it should be considered in the reconstructive armamentarium for penile shaft lesions. PMID:24966995

  11. Extracorporeal Free Flap Perfusion in Case of Prolonged Ischemia Time.

    PubMed

    Taeger, C D; Präbst, K; Beier, J P; Meyer, A; Horch, R E

    2016-04-01

    In free flap surgery, a clinically established concept still has to be found for the reduction of ischemia-related cell damage in the case of prolonged ischemia. Although promising results using extracorporeal free flap perfusion in the laboratory have been published in the past, until now this concept has not yet paved its way into clinical routine. This might be due to the complexity of perfusion systems and a lack of standardized tools. Here, we want to present the results of the first extracorporeal free flap perfusion in a clinical setting using a simple approach without the application of a complex perfusion machinery.

  12. Spectacles under Pedicles: Eyewear Modification with the Paramedian Forehead Flap

    PubMed Central

    Qu, Linda T.; Kelpin, John P.; Komorowska-Timek, Ewa

    2016-01-01

    Summary: The paramedian forehead flap is a widely used method of nasal reconstruction. The flap requires a bridge of tissue from forehead to the nose, for a period of 2 to 3 weeks, before it can be divided at a second procedure. During this time, patients often have difficulty positioning and wearing their eyewear underneath the pedicle of the flap. Here we present a novel approach to the problem. It requires only a simple modification to the patient’s eyewear and greatly facilitates wear and removal. PMID:27622084

  13. Pre-expanded Anterolateral Thigh Perforator Flap for Phalloplasty.

    PubMed

    D'Arpa, Salvatore; Colebunders, Britt; Stillaert, Filip; Monstrey, Stan

    2017-01-01

    The anterolateral thigh (ALT) perforator flap for phalloplasty is gaining popularity because it avoids the well-known scars of the radial forearm flap. However, scars are not eliminated, just moved to a different location, the thigh, that can for some patients be of great sexual value. Preexpansion of the ALT flap allows primary donor site closure, thus avoiding not only the unsightly appearance of a skin grafted ALT donor site, but also the skin graft donor site scar. Preoperative perforator location by means of computed tomography angiography allows safe expander placement through 2 small remote incisions.

  14. Compound or Specially Designed Flaps in the Lower Extremities.

    PubMed

    Battiston, Bruno; Ciclamini, Davide; Tang, Jin Bo

    2017-04-01

    Novel and combined tissue transfers from the lower extremity provide new tools to combat soft tissue defects of the hand, foot, and ankle, or fracture nonunion. Flaps can be designed for special purposes, such as providing a gliding bed for a grafted or repaired tendon or for thumb or finger reconstruction. Propeller flaps can cover soft tissue defects of the leg and foot. In repairing severe bone and soft tissue defects of the lower extremity, combined approaches, including external fixators, one-stage vascularized bone grafting, and skin or muscle flap coverage of the traumatized leg and foot, have become popular.

  15. The flap by flap dissection in terminal ballistic applied to less lethal weapons.

    PubMed

    de Freminville, Humbert; Rongieras, Fréderic; Prat, Nicolas; Voiglio, Eric J

    2011-06-01

    Medical examiners often have to solve questions such as firing distance and bullet trajectory for lethal weapons. Knowledge in the field of terminal ballistics has increased during the last 30 years and layer by layer dissection reveals superficial wounds that can be linked with the permanent cavity. At the end of the 1990s, terminal ballistics also focused on less lethal weapons and their wounds. Here, 2 different less lethal weapons with single bullets were tested on nonembalmed and undressed cadavers (N = 26) at different ranges and speeds. We have developed a technique for dissection which we call flap by flap dissection that reveals the advantage of the bullet-skin-bone entity, the absence of wounds linking its components and range of less lethal weapons.

  16. Workhorse Flaps in Chest Wall Reconstruction: The Pectoralis Major, Latissimus Dorsi, and Rectus Abdominis Flaps

    PubMed Central

    Bakri, Karim; Mardini, Samir; Evans, Karen K.; Carlsen, Brian T.; Arnold, Phillip G.

    2011-01-01

    Large and life-threatening thoracic cage defects can result from the treatment of traumatic injuries, tumors, infection, congenital anomalies, and radiation injury and require prompt reconstruction to restore respiratory function and soft tissue closure. Important factors for consideration are coverage with healthy tissue to heal a wound, the potential alteration in respiratory mechanics created by large extirpations or nonhealing thoracic wounds, and the need for immediate coverage for vital structures. The choice of technique depends on the size and extent of the defect, its location, and donor site availability with consideration to previous thoracic or abdominal operations. The focus of this article is specifically to describe the use of the pectoralis major, latissimus dorsi, and rectus abdominis muscle flaps for reconstruction of thoracic defects, as these are the workhorse flaps commonly used for chest wall reconstruction. PMID:22294942

  17. Wuho Is a New Member in Maintaining Genome Stability through its Interaction with Flap Endonuclease 1

    PubMed Central

    Cheng, I-Cheng; Chen, Betty Chamay; Shuai, Hung-Hsun; Chien, Fan-Ching; Chen, Peilin; Hsieh, Tao-shih

    2016-01-01

    Replication forks are vulnerable to wayward nuclease activities. We report here our discovery of a new member in guarding genome stability at replication forks. We previously isolated a Drosophila mutation, wuho (wh, no progeny), characterized by a severe fertility defect and affecting expression of a protein (WH) in a family of conserved proteins with multiple WD40 repeats. Knockdown of WH by siRNA in Drosophila, mouse, and human cultured cells results in DNA damage with strand breaks and apoptosis through ATM/Chk2/p53 signaling pathway. Mice with mWh knockout are early embryonic lethal and display DNA damage. We identify that the flap endonuclease 1 (FEN1) is one of the interacting proteins. Fluorescence microscopy showed the localization of WH at the site of nascent DNA synthesis along with other replication proteins, including FEN1 and PCNA. We show that WH is able to modulate FEN1’s endonucleolytic activities depending on the substrate DNA structure. The stimulatory or inhibitory effects of WH on FEN1’s flap versus gap endonuclease activities are consistent with the proposed WH’s functions in protecting the integrity of replication fork. These results suggest that wh is a new member of the guardians of genome stability because it regulates FEN1’s potential DNA cleavage threat near the site of replication. PMID:26751069

  18. Comparison of modified Limberg flap and Karydakis flap operations in pilonidal sinus surgery: prospective randomized study.

    PubMed

    Tokac, Mehmet; Dumlu, Ersin Gurkan; Aydin, Murat Seyit; Yalcın, Abdussamed; Kilic, Mehmet

    2015-05-01

    The best surgical technique for pilonidal sinus disease (PSD) is still disputed. The objective of this prospective randomized study is to compare the short and long-term results of modified Limberg flap and Karydakis flap surgeries that have been widely used in recent years. Ninety one patients were included in the study. The patients were divided into two groups: modified Limberg flap (MLF; n = 46) and Karydakis flap (KF; n = 45). Preoperative findings of the patients, their surgical findings, and short and long-term postoperative findings were recorded and statistically compared. While no significant difference was discovered between the groups in terms of postoperative analgesic need, hospital stay, postoperative infection rate, drain stay time, painless sitting time, painless toilet-sitting time, and painless walking time, return to work or school time was shorter in the MLF group compared with the KF group (20.61 ± 7.89 days, 23.29 ± 6.42, respectively; P < 0.05). Cosmetically, the visual analog scale (VAS) of the KF group was significantly higher than that of the MLF group (VAS score 7.12 ± 1.28, 5.45 ± 1.77, respectively; P < 0.05). Considering recurrence rates, no statistically significant difference was found between the groups. Our study found out that short and long-term results of the MLF and KF procedures are similar. We believe both methods can be safely used in surgical PSD treatment given that in the MLF procedure, shorter return-to-work time is achieved, while the procedure provides better cosmetic results.

  19. What Is the Ideal Free Flap for Soft Tissue Reconstruction? A Ten-Year Experience of Microsurgical Reconstruction Using 334 Latissimus Dorsi Flaps From a Universal Donor Site.

    PubMed

    Kim, Jeong Tae; Kim, Sang Wha; Youn, Seungki; Kim, Youn Hwan

    2015-07-01

    Microsurgical free tissue transfer is regarded as the best available method of tissue reconstruction for intractable defects. The ideal soft tissue flap is thought to be the anterolateral thigh flap. On the basis of 334 procedures involving the latissimus dorsi (LD) flap, we discuss the advantages of the LD flap over the current universal option, and we aimed to establish whether the LD could also gain universal status in all reconstructive fields.Three hundred thirty-four reconstructive procedures using the LD flap were performed in 322 patients between September 2002 and July 2012. In accordance with defect characteristics, we performed 334 procedures using flaps, which included the LD muscle flap with skin graft, the myocutaneous flap, the muscle-sparing flap, the perforator flap, the chimeric flap, and the 2-flap technique using the serratus anterior branch.Flap-related complications occurred in 21 patients (6.3%), including total and partial flap failure. In 253 cases, the donor site was closed primarily, and in the remaining cases, we used split-thickness skin grafts. Donor-site complications occurred in 20 cases (6%). In 11 of the 182 cases, no suitable perforators were identified during surgery.The advantages of the LD as a donor site include the possibility of various harvesting positions without position change, versatility of components, availability of muscle to fill extensive defects, and presence of thick fascia to enable full abdominal reconstruction. On the basis of our experience, we concluded that this flap has the potential to be used as widely as, or in preference to, the anterolateral thigh flap in most reconstructive areas.

  20. Anomalous superficial ulnar artery based flap

    PubMed Central

    Ramani, C. V.; Kundagulwar, Girish K.; Prabha, Yadav S.; Dushyanth, Jaiswal

    2014-01-01

    Upper limb shows a large number of arterial variations. This case report describes the presence of additional superficial ulnar artery which was used to raise a pedicle flap to cover an arm defect thus avoided using the main vessel of the forearm - radial or ulnar artery. Vascular anomalies occurring in the arm and forearm tend to increase the likelihood of damaging the superficial anomalous arteries during surgery. Superficial ulnar or radial arteries have been described to originate from the upper third of the brachial artery; here we report the origin of the anomalous superficial ulnar artery originating from the brachial artery at the level of elbow with the concomitant presence of normal deep radial and ulnar arteries. PMID:24987217

  1. Splash jet and slamming generated by a rotating flap

    NASA Astrophysics Data System (ADS)

    Sun, S. Y.; Sun, S. L.; Ren, H. L.; Wu, G. X.

    2015-09-01

    The hydrodynamic problem of slamming generated by a rotating flap, commonly known as Oyster in the wave energy sector, plunging into water, is analysed based on the incompressible velocity potential theory. The problem is solved through the boundary element method in the time domain. Two typical case studies are undertaken. One is the flap plunging into calm water and the other into an incoming wave. The splash jet formed during the flap plunging is included in the simulation. When the jet meets the main flow, it is treated through the domain decomposition method without taking account the secondary impact, which is similar to the mathematical method of Riemann's second sheet in the complex plane. The problem is solved in each non-overlapping subdomain, and the velocity and pressure continuity condition is imposed on the interface of the subdomains. Detailed results for the flap plunging into water with different velocities or accelerations are provided. The gravity and wave effects are also investigated.

  2. The Vascularized Medial Femoral Corticoperiosteal Flap for Thumb Reconstruction

    PubMed Central

    Amin, Kavit; Darhouse, Nagham; Sivakumar, Bran; Floyd, David

    2015-01-01

    Summary: We present an interesting method of shaping a vascularized medial femoral condyle (MFC) flap into a “neophalanx” for phalangeal reconstruction. Our patient presented with limited strength and function secondary to fracture nonunion of the proximal phalanx of the dominant thumb. Following excision of the pseudarthrosis, an MFC corticoperiosteal flap was harvested, sculpted into a prism shape and inset. The superomedial genicular pedicle was anastomosed to the princeps pollicis artery and a cephalic tributary. On follow-up, new bone growth was seen on radiographs and the patient had substantially improved function, with full metacarpophalangeal extension, a Kapandji score of 9, and a markedly reduced Disabilities of the Arm, Shoulder and Hand score of 2.68. The MFC flap is useful for reconstruction of bony defects, with minimal donor morbidity. This versatile vascularized flap can be crafted to requisite shapes and is useful for small defects in the hand, including phalangeal reconstruction. PMID:26495205

  3. A totally laparoscopic peritoneal free flap for reconstruction of hand.

    PubMed

    Guo, En-Qi; Xie, Qing-Ping

    2016-10-01

    Management of defects on the hand and foot with exposed tendons remains a major challenge for plastic surgeons. Here, we present a case of hand reconstruction with a totally laparoscopic peritoneal flap. The anterior rectus sheath was preserved in situ. The peritoneal free flap supplied by peritoneal branches of the deep inferior epigastric artery was retrieved by laparoscopy to cover the soft tissue defect of the hand. The defect of the dorsal hand was 17 cm ×12 cm. The peritoneal flap measuring 22 cm × 15 cm survived completely without any complications. A following split-thickness skin graft offered the suc- cessful wound closure. Motor and sensory function improved gradually within the first year follow-up. The totally laparoscopic peritoneal free flap is a good choice for reconstruction of the soft tissue de- fects accompanied by exposed tendons on the hand and foot.

  4. Flap motion of helicopter rotors with novel, dynamic stall model

    NASA Astrophysics Data System (ADS)

    Han, Wei; Liu, Jie; Liu, Chun; Chen, Lei; Su, Xichao; Zhao, Peng

    2016-01-01

    In this paper, a nonlinear flapping equation for large inflow angles and flap angles is established by analyzing the aerodynamics of helicopter blade elements. In order to obtain a generalized flap equation, the Snel stall model was first applied to determine the lift coefficient of the helicopter rotor. A simulation experiment for specific airfoils was then conducted to verify the effectiveness of the Snel stall model as it applies to helicopters. Results show that the model requires no extraneous parameters compared to the traditional stall model and is highly accurate and practically applicable. Based on the model, the relationship between the flapping angle and the angle of attack was analyzed, as well as the advance ratio under the dynamic stall state.

  5. High-flaps for natural laminar flow airfoils

    NASA Technical Reports Server (NTRS)

    Morgan, Harry L.

    1986-01-01

    A review of the NACA and NASA low-drag airfoil research is presented with particular emphasis given to the development of mechanical high-lift flap systems and their application to general aviation aircraft. These flap systems include split, plain, single-slotted, and double-slotted trailing-edge flaps plus slat and Krueger leading-edge devices. The recently developed continuous variable-camber high-lift mechanism is also described. The state-of-the-art of theoretical methods for the design and analysis of multi-component airfoils in two-dimensional subsonic flow is discussed, and a detailed description of the Langley MCARF (Multi-Component Airfoil Analysis Program) computer code is presented. The results of a recent effort to design a single- and double-slotted flap system for the NASA high speed natural laminar flow (HSNLF) (1)-0213 airfoil using the MCARF code are presented to demonstrate the capabilities and limitations of the code.

  6. [Hypogastric abdominal wall reconstruction with a pedicled anterolateral thigh flap].

    PubMed

    Moullot, P; Philandrianos, C; Gonnelli, D; Casanova, D

    2014-10-01

    Looking at a full-thickness abdominal wall defect, it is necessary to use reconstructive surgery techniques. The authors present an original case of reconstruction of the abdominal wall, using an anterolateral thigh flap (ALT) harvested with vascularised fascia lata. We describe the advantages of this technique, which has rarely been used for this indication. An 80-year-old woman presenting a full-thickness abdominal wall defect of 15×18cm was reconstructed by a pedicled ALT flap. Skin wound healing was obtained within 15 days, with no complication. There was no donor site sequela. The pedicled ALT flap appears to be a good solution for hypogastric abdominal wall defect in a one step procedure. Vacularised fascia lata bring with the cutaneous flap is useful to reconstruct the abdominal fascia.

  7. Noninvasive Free Flap Monitoring Using Eulerian Video Magnification

    PubMed Central

    Liu, Yuan Fang; Vuong, Christopher; Walker, Paul Charles; Peterson, Nathaniel Ray; Inman, Jared Christian; Filho, Pedro Alcantara Andrade; Lee, Steve Choon-Sung

    2016-01-01

    Eulerian Video Magnification (EVM) can enhance subtle changes in videos to reveal what was once invisible to the naked eye. In this proof of concept study, we investigated using EVM as a novel form of free flap monitoring. Free flaps with skin paddles were filmed in the operating room with manipulation of their pedicles. In a representative 77-year-old female who received a latissimus dorsi-serratus-rib composite free flap, EVM was able to detect blockage of arterial or venous supply instantaneously, providing a visible representation through degree of color change in videos. EVM has the potential to serve as a powerful free flap monitoring tool with the benefit of being noninvasive, sensitive, easy-to-use, and nearly cost-free. PMID:27092284

  8. Vortex Flap Technology: a Stability and Control Assessment

    NASA Technical Reports Server (NTRS)

    Carey, K. M.; Erickson, G. E.

    1984-01-01

    A comprehensive low-speed wind tunnel investigation was performed of leading edge vortex flaps applied to representative aircraft configurations. A determination was made of the effects of analytically- and empirically-designed vortex flaps on the static longitudinal and lateral-directional aerodynamics, stability, and control characteristics of fighter wings having leading-edge sweep angles of 45 to 76.5 degrees. The sensitivity to several configuration modifications was assessed, which included the effects of flap planform, leading- and trailing-edge flap deflection angles, wing location on the fuselage, forebody strakes, canards, and centerline and outboard vertical tails. Six-component forces and moments, wing surface static pressure distributions, and surface flow patterns were obtained using the Northrop 21- by 30-inch low-speed wind tunnel.

  9. External Dacryocystorhinostomy With or Without Double Mucosal Flap Anastomosis: Comparison of Surgical Outcomes.

    PubMed

    Takahashi, Yasuhiro; Mito, Hidenori; Kakizaki, Hirohiko

    2015-06-01

    The aim of this study was to compare surgical outcomes of external dacryocystorhinostomy with or without double mucosal flap anastomosis. A retrospective chart review was performed for 205 sides of 178 patients diagnosed with nasolacrimal duct obstruction. Double-flap anastomosis was performed on 57 sides (double-flap group) and complete flap excision on 148 sides (no-flap group). Criteria for surgical success were defined as no or minimal intermittent epiphora and no reflux on lacrimal irrigation 12 months postoperatively. Consequently, surgery was successful for 53 sides (93.0%) in the double-flap group and 138 sides (93.2%) in the no-flap group. There was no statistically significant difference in success rate between the groups (P = 0.947, the Fisher exact probability test). This study demonstrated that external dacryocystorhinostomy without flap anastomosis had a surgical outcome similar to that of double-flap anastomosis.

  10. Lateral Arm Free Flap With Preservation of the Posterior Antebrachial Cutaneous Nerve.

    PubMed

    Ki, Sae Hwi

    2016-05-01

    The lateral arm free flap offers many advantages in reconstruction of soft tissue defect and reconstruction of extremities. However, this free flap is associated with sensory loss at the posterior forearm due to injury of the posterior antebrachial cutaneous nerve (PABCN).The PABCN-sparing lateral arm free flaps were performed in 19 patients with various soft tissue defects of the extremity, and the outcomes of free flap reconstructions using this modification are evaluated. All flaps survived without partial necrosis. Three patients experienced transient sensory loss in the posterior area of the forearm after flap harvest.In this study, lateral arm free flaps can be elevated without necessarily sacrificing the PABCN. This nerve-sparing modification decreases the donor-site morbidity of lateral arm free flaps and further increases the overall usefulness of this flap in soft tissue reconstructions of the extremities.

  11. Full-scale upper-surface-blown flap noise. [for short haul STOL aircraft

    NASA Technical Reports Server (NTRS)

    Heidelberg, L. J.; Homyak, L.; Jones, W. L.

    1975-01-01

    A highly noise-suppressed TF 34 engine was used to investigate the noise of several powered lift configurations involving upper-surface-blown (USB) flaps. The configuration variables were nozzle type (i.e. slot and circular with deflector), flap chord-length, and flap angle. The results of velocity surveys at both the nozzle exit and the flap trailing edge are used for correlation of the noise data. Configurations using a long flap design were 4 dB quieter than a short flap typical of current trends in USB flap design. The lower noise for the long flap is attributed primarily to the greater velocity decay of the jet at the flap trailing edge. The full-scale data revealed substantially more quadrupole noise in the region near the deflected jet than observed in previous sub-scale tests.

  12. PECASE: Soaring Mechanisms for Flapping-Wing Micro Air Vehicles

    DTIC Science & Technology

    2015-03-31

    stability (e.g. using a positive wing dihedral). Many insects effectively use gliding modes to extend flight duration - for example. Monarch...strategies for flapping/gliding intermittent flight through the development of a robotic insect capable of bio-inspired flapping/gliding flight and a...apply this to increase the performance of insect -scale MAVs. 15. SUBJECT TERMS micro air vehicles, bioinspired flight, bioinspired robotics 16

  13. Biologically-Inspired Anisotropic Flexible Wing for Optimal Flapping Flight

    DTIC Science & Technology

    2013-07-01

    flapping wing MAV with parameters similar to several biological systems like the bumblebee, hawkmoth, and hummingbird was identified and used as the...have been measure. Leading edge pivot produces much higher force that trailing edge pivot. Also at high pitch rates the flow evolution is more two...small synthetic wings which were biologically inspired by hummingbirds as they are comparable in size, shape, and flapping frequency. The focus was

  14. Flap Side Edge Liners for Airframe Noise Reduction

    NASA Technical Reports Server (NTRS)

    Jones, Michael G. (Inventor); Khorrami, Mehdi R. (Inventor); Choudhari, Meelan M. (Inventor); Howerton, Brian M. (Inventor)

    2014-01-01

    One or more acoustic liners comprising internal chambers or passageways that absorb energy from a noise source on the aircraft are disclosed. The acoustic liners may be positioned at the ends of flaps of an aircraft wing to provide broadband noise absorption and/or dampen the noise producing unsteady flow features, and to reduce the amount of noise generated due to unsteady flow at the inboard and/or outboard end edges of a flap.

  15. Vortex shedding noise of a cylinder with hairy flaps

    NASA Astrophysics Data System (ADS)

    Kamps, Laura; Geyer, Thomas F.; Sarradj, Ennes; Brücker, Christoph

    2017-02-01

    This study describes the modification of acoustic noise emitted from cylinders in a stationary subsonic flow for a cylinder equipped with flexible hairy flaps at the aft part as a passive way to manipulate the flow and acoustics. The study was motivated by the results from previous water tunnel measurements, which demonstrated that hairy flaps can modify the shedding cycle behind the cylinder and can reduce the wake deficit. In the present study, wind tunnel experiments were conducted on such a modified cylinder and the results were compared to the reference case of a plain cylinder. The acoustic spectrum was measured using two microphones while simultaneously recording the flap motion. To further examine the flow structures in the downstream vicinity of the cylinder, constant temperature anemometry measurements as well as flow visualizations were also performed. The results show that, above a certain Reynolds number, the hairy flaps lead to a jump in the vortex shedding frequency. This phenomenon is similarly observed in the water flow experiments as a jump in the non-dimensional Strouhal number that is related to the change of the shedding cycle. This jump appears to be coupled to a resonant excitation of the flaps. The specific Reynolds number at which the jump occurs is higher in the present case, which is attributed to the lower added mass in air as compared with the one in water. The flow visualizations confirmed that such action of the flaps lead to a more slender elongated shape of the time-averaged separation bubble. In addition, the hairy flaps induce a noticeable reduction of the tonal noise as well as broadband noise as long as the flaps do not touch each other.

  16. The lateral upper arm flap: anatomy and clinical applications.

    PubMed

    Katsaros, J; Schusterman, M; Beppu, M; Banis, J C; Acland, R D

    1984-06-01

    There is a highly dependable free flap donor site of moderate size on the posterolateral aspect of the distal upper arm. The area is supplied by the posterior radial collateral artery, a direct continuation of the profunda brachii. The flap area is supplied by a direct cutaneous nerve. It can be raised on its own, with underlying tendon, with bone, or with fascia only. This article describes our findings in 32 cadaver dissections and in 23 clinical cases.

  17. Surgeon-Based 3D Printing for Microvascular Bone Flaps.

    PubMed

    Taylor, Erin M; Iorio, Matthew L

    2017-03-04

    Background Three-dimensional (3D) printing has developed as a revolutionary technology with the capacity to design accurate physical models in preoperative planning. We present our experience in surgeon-based design of 3D models, using home 3D software and printing technology for use as an adjunct in vascularized bone transfer. Methods Home 3D printing techniques were used in the design and execution of vascularized bone flap transfers to the upper extremity. Open source imaging software was used to convert preoperative computed tomography scans and create 3D models. These were printed in the surgeon's office as 3D models for the planned reconstruction. Vascularized bone flaps were designed intraoperatively based on the 3D printed models. Results Three-dimensional models were created for intraoperative use in vascularized bone flaps, including (1) medial femoral trochlea (MFT) flap for scaphoid avascular necrosis and nonunion, (2) MFT flap for lunate avascular necrosis and nonunion, (3) medial femoral condyle (MFC) flap for wrist arthrodesis, and (4) free fibula osteocutaneous flap for distal radius septic nonunion. Templates based on the 3D models allowed for the precise and rapid contouring of well-vascularized bone flaps in situ, prior to ligating the donor pedicle. Conclusions Surgeon-based 3D printing is a feasible, innovative technology that allows for the precise and rapid contouring of models that can be created in various configurations for pre- and intraoperative planning. The technology is easy to use, convenient, and highly economical as compared with traditional send-out manufacturing. Surgeon-based 3D printing is a useful adjunct in vascularized bone transfer. Level of Evidence Level IV.

  18. Fasciocutaneous flap in esophageal stricture with ventriculoperitoneal shunt.

    PubMed

    Seong, Yong Won; Kang, Chang Hyun; Chang, Hak; Park, In Kyu; Kim, Young Tae

    2014-01-01

    Abdominal surgery in a patient with ventriculoperitoneal shunt may increase the risk of shunt malfunction and infection. We present a successful case of resection and reconstruction of the cervical esophagus by rolled lateral thoracic artery fasciocutaneous flap in a patient with corrosive esophageal stricture and preexisting ventriculoperitoneal shunt. Follow-up esophagogastroscopy after 3 months revealed wide patent graft. Rolled fasciocutaneous flap may be a safe alternative treatment without risk of shunt-associated complications in a patient with ventriculoperitoneal shunt.

  19. Wind Tunnel Test of the SMART Active Flap Rotor

    NASA Technical Reports Server (NTRS)

    Straub, Friedrich K.; Anand, Vaidyanthan R.; Birchette, Terrence S.; Lau, Benton H.

    2009-01-01

    Boeing and a team from Air Force, NASA, Army, DARPA, MIT, UCLA, and U. of Maryland have successfully completed a wind-tunnel test of the smart material actuated rotor technology (SMART) rotor in the 40- by 80-foot wind-tunnel of the National Full-Scale Aerodynamic Complex at NASA Ames Research Center. The Boeing SMART rotor is a full-scale, five-bladed bearingless MD 900 helicopter rotor modified with a piezoelectric-actuated trailing edge flap on each blade. The eleven-week test program evaluated the forward flight characteristics of the active-flap rotor at speeds up to 155 knots, gathered data to validate state-of-the-art codes for rotor aero-acoustic analysis, and quantified the effects of open and closed loop active flap control on rotor loads, noise, and performance. The test demonstrated on-blade smart material control of flaps on a full-scale rotor for the first time in a wind tunnel. The effectiveness of the active flap control on noise and vibration was conclusively demonstrated. Results showed significant reductions up to 6dB in blade-vortex-interaction and in-plane noise, as well as reductions in vibratory hub loads up to 80%. Trailing-edge flap deflections were controlled within 0.1 degrees of the commanded value. The impact of the active flap on control power, rotor smoothing, and performance was also demonstrated. Finally, the reliability of the flap actuation system was successfully proven in more than 60 hours of wind-tunnel testing.

  20. Vertically Set Sombrero-shaped Abdominal Flap for Asian Breast Reconstruction after Skin-sparing Mastectomy

    PubMed Central

    Yoshimura, Kotaro; Asahi, Rintaro; Sarukawa, Syunji; Sunaga, Ataru; Kamochi, Hideaki; Sugawara, Yasushi

    2016-01-01

    Background: Immediate autologous breast reconstruction after skin-sparing mastectomy is an esthetically superior method, and a free abdominal flap is often used. However, in Asian patients, little redundant abdominal skin and thin subcutaneous tissue are common, necessitating the development of a more suitable flap design and setting. We devised a narrow flap, the sombrero-shaped flap (S-flap), set vertically, to reduce postoperative abdominal morbidity without sacrificing cosmetic results. Methods: To assess this new flap design and setting, the recipient- and donor-site complications of consecutive patients treated by S-flap (n = 40) and conventional flap (C-flap) (n = 22) were retrospectively investigated. Postoperative abdominal pain, stiffness, and patient activity were also assessed in each group with our original grading scale. Results: Compared with the C-flap group, the S-flap group had a significantly lower skin paddle vertical height (mean, 14.0 and 10.2 cm, respectively; P < 0.001), lower abdominal stiffness (P = 0.023), and higher rate of double-pedicled flap use (27.3% and 52.5%, respectively; P < 0.048). The rates of donor and recipient site complications, postoperative abdominal pain, and activity did not significantly differ between the groups. Conclusions: For immediate breast reconstruction after skin-sparing mastectomy in Asian patients, our newly designed S-flap and vertical flap setting achieved cosmetically good, consistent results with low abdominal morbidity, even though the abdominal flap was thin and narrow. The viability of the S-flap, including medial fan-shaped adipose flap, was reliable, even though the flap often required elevation with double pedicles. PMID:28293497

  1. Predictive risk factors of free flap thrombosis in breast reconstruction surgery.

    PubMed

    Masoomi, Hossein; Clark, Emily G; Paydar, Keyianoosh Z; Evans, Gregory R D; Nguyen, Audrey; Kobayashi, Mark R; Wirth, Garrett A

    2014-11-01

    Vascular thrombosis is one of the major postoperative complications of free flap microvascular breast reconstruction operations. It is associated with higher morbidity, higher cost, increased length of hospital stay, and potentially flap loss. Our purpose is to evaluate the rate of this complication and whether patient characteristics play a role. Using the Nationwide Inpatient Sample (NIS) database, we examined the clinical data of patients who underwent free flap breast reconstruction between 2009 and 2010 in the United States. Multivariate and univariate regression analyses were performed to identify independent risk factors of flap thrombosis. A total of 15,211 patients underwent free flap breast reconstruction surgery (immediate reconstruction: 43%). The most common flap was the free deep inferior epigastric perforator (DIEP) flap (53.6%), followed by free transverse rectus abdominis myocutaneous (TRAM) flap (43.1%), free superficial inferior epigastric artery (SIEA) flap (2%), and free gluteal artery perforator (GAP) flap (1.3%). The overall rate of flap thrombosis was 2.4 %, with the highest rate seen in the SIEA group (11.4%) and the lowest in the TRAM group (1.7%). Peripheral vascular disease (adjusted odds ration [AOR] 10.61), SIEA flap (AOR, 4.76) and delayed reconstruction (AOR, 1.42) were found to be statistically significant risk factors for flap thrombosis. Other comorbidities were not linked. While the overall rate of flap thrombosis in free flap breast reconstruction was relatively low (2.4%), Plastic Surgeons should be aware that patients with peripheral vascular disease and those undergoing free SIEA flap are at higher risk of flap thrombosis and they should closely monitor flaps to increase the chance for early salvage.

  2. FAMM Flap in Reconstructing Postsurgical Nasopharyngeal Airway Stenosis

    PubMed Central

    Nangole, Ferdinand Wanjala; Khainga, Stanley Ominde

    2014-01-01

    Introduction. Postsurgical nasopharyngeal airway stenosis can be a challenge to manage. The stenosis could be as a result of any surgical procedure in the nasopharyngeal region that heals extensive scarring and fibrosis. Objective. To evaluate patients with nasopharyngeal stenosis managed with FAMM flap. Study Design. Prospective study of patients with nasopharyngeal stenosis at the Kenyatta National Hospital between 2010 and 2013 managed with FAMM flap. Materials and Methods. Patients with severe nasopharyngeal airway stenosis were reviewed and managed with FAMM flaps at the Kenyatta National Hospital. Postoperatively they were assessed for symptomatic improvement in respiratory distress, patency of the nasopharyngeal airway, and donor site morbidity. Results. A total of 8 patients were managed by the authors in a duration of 4 years with nasopharyngeal stenosis. Five patients were managed with unilateral FAMM flaps in a two-staged surgical procedure. Four patients had complete relieve of the airway obstruction with a patent airway created. One patient had a patent airway created though with only mild improvement in airway obstruction. Conclusion. FAMM flap provides an alternative in the management of postsurgical severe nasopharyngeal stenosis. It is a reliable flap that is easy to raise and could provide adequate epithelium for the stenosed pharynx. PMID:25328699

  3. Compliant topology optimization for planar passive flap micro valve.

    PubMed

    Yoon, Gil Ho

    2014-10-01

    This paper reports the compliant topology optimization for planar passive flap micro valve considering fluid-structure interaction with a monolithic approach. Although flap valve type check valve is easy to manufacture and use for the applications for Bio/Nano/MEMS, its structural optimization has been seldom conducted so far. The size of the Bio/Nano/MEMS devices becomes smaller and the simple straight type micro valve structure is required to be optimized considering fluid speed. To address this optimization problem, the structural topology optimization scheme which designs optimal topologies is applied for a flap type check valve structure. To consider the coupling effects of fluid domain and structural domain, the monolithic finite element approach is employed. In the new analysis approach, solid domain is simulated by introducing the inverse permeability in the Navier-Stokes equation and the fluid stress filter in the linear elasticity equation. Also it is a new idea that fluid domain is simulated by finite elements with a weak Young's modulus in the linear elasticity equation. The mutual couplings between fluid and structure are considered by the introduction of the deformation tensor which is one of the basic concepts of the continuum mechanism. By distributing material properties inside a design domain for compliant flap, optimal flap structures can be constructed with different fluid speeds. By investigating the optimal layouts of several passive flap designs, we prove that the structural topology optimization can provide optimal layouts for Bio, Nano, and MEMS applications.

  4. A triceps musculocutaneous flap for chest-wall defects

    SciTech Connect

    Hartrampf, C.R. Jr.; Elliott, L.F.; Feldman, S. )

    1990-09-01

    A posterior upper arm flap based on the profunda brachii vessels has been described to cover soft-tissue defects in the upper anterolateral chest. In our series, the posterior upper arm skin is elevated with the long head of the triceps muscle to cover seven chest-wall defects resulting from indolent postradiation open wounds following partial TRAM flap failure (n = 2), soft-tissue deficiencies following partial TRAM flap loss (n = 3), and primarily as an ancillary flap in TRAM flap breast reconstruction (n = 2). This flap also may be used to supply well-vascularized tissue in the regions of the shoulder, axilla, and posterolateral back. A prerequisite for this operation is redundant tissue of the upper arm often present in middle-aged women and in patients with lymphedema following mastectomy. In our series of seven patients, all donor sites were closed primarily, and there was no subjective functional deficit following transfer of the long head of the triceps muscle.

  5. The impact of Pfannenstiel scars on TRAM flap complications.

    PubMed

    Dayhim, Fariba; Wilkins, Edwin G

    2004-11-01

    For the past two decades, the transverse rectus abdominis musculocutaneous (TRAM) flap has been a mainstay of postmastectomy breast reconstruction. Because the flap depends on musculocutaneous perforating vessels from the rectus muscle for survival, some authors have raised concerns about increased risks of TRAM flap loss in patients with scars from previous abdominal surgeries, particularly those with Pfannenstiel scars. To assess the effects of Pfannenstiel scars on complication rates, we retrospectively evaluated the inpatient and outpatient records of 241 patients undergoing TRAM reconstruction in a single institution over an 11-year period. Of these patients, 51 had previous Pfannenstiel scars. while 190 did not. Controlling for potential confounding variables (body mass index and timing of reconstruction), logistic regressions found no significant differences between the Pfannenstiel and nonPfannenstiel cohorts in the rate of flap loss (15.7% and 20%, respectively; P = 0.376) or in the incidence of postoperative abdominal donor site laxity (17.6% and 12.1%, respectively; P= 0.361). Within the Pfannenstiel group, the type of TRAM reconstruction (ie, pedicle versus free flaps) did not have a significant effect on complication rates. We conclude that previous concerns over the impact of preexisting Pfannenstiel scars on TRAM flap complications are unfounded.

  6. Flap Conformations in HIV-1 Protease are Altered by Mutations

    NASA Astrophysics Data System (ADS)

    Fanucci, Gail; Blackburn, Mandy; Veloro, Angelo; Galiano, Luis; Fangu, Ding; Simmerling, Carlos

    2009-03-01

    HIV-1 protease (PR) is an enzyme that is a major drug target in the treatment of AIDS. Although the structure and function of HIV-1 PR have been studied for over 20 years, questions remain regarding the conformations and dynamics of the β-hairpin turns (flaps) that cover the active site cavity. Distance measurements with pulsed EPR spectroscopy of spin labeled constructs of HIV-1 PR have been used to characterize the flap conformations in the apo and inhibitor bound states. From the most probably distances and the breadth of the distance distribution profiles from analysis of the EPR data, insights regarding the flap conformations and flexibility are gained. The EPR results clearly show how drug pressure selected mutations alter the average conformation of the flaps and the degree of opening of the flaps. Molecular dynamics simulations successfully regenerate the experimentally determined distance distribution profiles, and more importantly, provide structural models for full interpretation of the EPR results. By combining experiment and theory to understand the role that altered flap flexibility/conformations play in the mechanism of drug resistance, key insights are gained toward the rational development of new inhibitors of this important enzyme.

  7. Identification of independent risk factors for flap failure: A retrospective analysis of 1530 free flaps for breast, head and neck and extremity reconstruction.

    PubMed

    Las, David E; de Jong, Tim; Zuidam, J Michiel; Verweij, Norbert M; Hovius, Steven E R; Mureau, Marc A M

    2016-07-01

    Reconstructive microsurgery is a powerful method of treating various complex defects. However, flap loss remains a possibility, leading to additional surgery, hospitalisation and costs. Consequently, it is important to know which factors lead to an increased risk of flap failure, so that measures can be undertaken to reduce this risk. Therefore, we analysed our results over a 20-year period to identify risk factors for flap failure after breast, head and neck and extremity reconstruction. The medical files of all patients treated between 1992 and 2012 were reviewed. Patient characteristics, surgical data and post-operative complications were scored, and independent risk factors for flap loss were identified. Reconstruction with a total of 1530 free flaps was performed in 1247 patients. Partial and total flap loss occurred in 5.5% and 4.4% of all free flaps, respectively. In all flaps, signs of compromised flap circulation were a risk factor for flap failure. More specifically, the risk factors for flap failure in breast reconstruction were previous radiotherapy, venous anastomosis revision, gluteal artery perforator (GAP) flap choice and post-operative bleeding. In head and neck reconstruction, pulmonary co-morbidity and anastomosis to the lingual vein or superficial temporal artery were risk factors, whereas a radial forearm flap reduced the risk. In extremity reconstruction, diabetes, prolonged anaesthesia time and post-operative wound infection were risk factors. Independent pre-, intra- and post-operative risk factors for flap failure after microvascular breast, head and neck and extremity reconstruction were identified. These results may be used to improve patient counselling and to adjust treatment algorithms to further reduce the chance of flap failure.

  8. The effect of learning curve on flap selection, re-exploration, and salvage rates in free flaps; A retrospective analysis of 155 cases.

    PubMed

    Demir, Ahmet; Kucuker, Ismail; Keles, Musa Kemal; Demirtas, Yener

    2013-10-01

    The purpose of this study is to report our experience and learning curve in avoiding complications at both the recipient and donor sites as well in choosing the best flap for different anatomic locations. For this purpose 155 free flaps done between October 2005 and August 2012 were retrospectively examined. Patient demographics, flap types, etiology, re-exploration indications, timing of the re-explorations, and salvage rates were documented. In the first 60 cases, our re-exploration rate was 26.7% (16 flaps), and the rate decreased to 15.0% for the second 60 flaps (9 flaps). In correlation with this decrease, in the last 35 cases, only three flaps were re-explored (8.6%). This decrease in re-exploration rates over time was statistically significant (P = 0.021). Re-exploration rates for axial and perforator flaps were 14.6% and 22.7%, respectively. Salvage rates were 76.9% in axial flaps and 53.3% in perforator flaps. The total success rate for axial flaps was 95.5% and for perforator flaps was 89.4%. Besides, re-exploration rates were higher with lower salvage rates in perforator flaps compared to axial flaps causing lower overall success rates in the former group. The mean time of re-explorations was 21.4 hours. Salvage rates were significantly higher in re-explorations done within the first 12 hours after the initial surgery than in re-explorations done after 12 hours (83.3% vs. 47.3%) (P = 0.040). We can conclude that axial flaps have a steeper learning curve and are safer options for the inexperienced reconstructive micro-surgeons until they have adequate experience with the perforator dissection.

  9. Repairs of Large Defects of the Lower Lid and the Infraorbital Region With Suspended Cheek Flaps With a Dermofat Flap.

    PubMed

    Selçuk, Caferi Tayyar; Erbatur, Serkan; Durgun, Mustafa; Calavul, Abdulkadir

    2016-09-01

    After the repair of large defects of the lower lid and the infraorbital region using larger flaps without adequate support, retractions of the lower lid may be observed due to the weight of the flap. In this study, the authors' aim is to present the outcome of the repairs they performed on large defect areas in the lower lid and the infraorbital region using cheek flaps suspended by a dermofat flap.The method was performed on 7 patients between 2011 and 2015. Among the patients, 4 were female, while 3 were male. The mean age of the patients was 61.3 (54-69) years. In all the patients, the defects were secondary to tumor excisions. The mean size of the defects was 4.4 × 5 cm (4 × 4 cm to 6 × 5 cm). In all the patients, the repair of the defect was performed using the Mustarde flaps prepared in the subcutaneous plane. After the flap was advanced to the defect area, a dermofat flap was prepared from the part at the lateral canthal area and was sutured to the periosteum superiorly to the lateral canthus.Patient satisfaction and functionality was high during the long-term follow-up. While minimal scleral show occurred in 1 patient, the lid position was normal in the other patients.The authors are of the opinion that the method they used may reduce the risk of lid deformities that may develop with the cheek flaps used to repair large lid defects.

  10. Successful reconstruction of irradiated anterior skull base defect using the dual flap technique involving local pericranial flap and radial forearm free flap.

    PubMed

    Yeo, In Sung; Kim, Se-Hyuk; Park, Myong Chul; Lim, Hyoseob; Kim, Joo Hyoung; Lee, Il Jae

    2014-07-01

    Skull base reconstruction presents a challenging therapeutic problem requiring a multispecialty surgical approach and close cooperation between the neurosurgeon, head and neck surgeon, as well as plastic and reconstructive surgeon during all stages of treatment. The principal goal of skull base reconstruction is to separate the intracranial space from the nasopharyngeal and oropharyngeal cavities, creating support for the brain and providing a water-tight barrier against cerebrospinal fluid leakage and ascending infection. We present a case involving a 58-year-old man with anterior skull base defects (2.5 cm × 3 cm) secondary to the removal of olfactory neuroblastoma. The patient received conventional radiation therapy at 6000 cGy in 30 fractions approximately a month before tumor removal. The patient had radiation therapy before surgery and was planned to have postoperative radiation therapy, which would lead to a higher complication rate of reconstruction. Artificial dura was used for the packing of the dural defect, which was also suspected to increase the complication rate of reconstruction. For these reasons, we chose to apply the dual flap technique, which uses both local pericranial flap and de-epithelized radial forearm free flap for anterior skull base defect to promote wound healing. During 28 months of follow-up after coverage of the anterior skull base defect, the dual flap survived completely, as confirmed through follow-up magnetic resonance imaging. The patient was free of cerebrospinal fluid leakage, meningitis, and abscess, and there was minimal donor-site morbidity of the radial forearm free flap. Reconstruction of anterior skull base defects using the dual flap technique is safe, reliable, and associated with low morbidity, and it is ideal for irradiated wounds and low-volume defects.

  11. Serratus anterior composite flaps for reconstruction of large-area oral and maxillofacial defects: a new neuromuscular flap.

    PubMed

    Tang, Wei; Long, Jie; Feng, Fan; Guo, Lijuan; Gao, Chao; Tian, Weidong

    2009-11-01

    Large area defects in the maxillofacial field are difficult to restore with sufficient esthetic and functional outcome. This study was to assess the feasibility of using serratus anterior composite flaps for reconstruction of large-area oral and maxillofacial tissue defects and to determine subsequent effects on neuromuscular function. Six patients with severe maxillofacial deformities were treated with serratus anterior composite flaps. The neurovascularized pedicle of each flap retained the long thoracic nerve to supply motor innervation. The long thoracic nerve was anastomosed with a branch of the facial nerve. The remaining fine branches of the facial nerve were separated interfascicularly and intrafascicularly, and then implanted within the border of the serratus anterior muscle. Transplanted flaps survived in all patients without vascular crisis. At the 12-month follow-up examinations, patients were able to close their eyes, wrinkle their forehead, and blow through pursed lips using the reconstructed mimetic muscles. The free serratus anterior composite flap has different digitations of the serratus anterior and motor nerve innervations, which is an attractive choice for reconstruction of large defects of oral and maxillofacial tissue. The nerve anastomosis and facial nerve replantation technique may protect the pedicle from atrophy of the transferred flap. Facial motion can be animated by neurotization or reinnervation in-growth in the neurotized slips of the serratus.

  12. A computer program to calculate the longitudinal aerodynamic characteristics of wing-flap configurations with externally blown flaps

    NASA Technical Reports Server (NTRS)

    Mendenhall, M. R.; Goodwin, F. K.; Spangler, S. B.

    1976-01-01

    A vortex lattice lifting-surface method is used to model the wing and multiple flaps. Each lifting surface may be of arbitrary planform having camber and twist, and the multiple-slotted trailing-edge flap system may consist of up to ten flaps with different spans and deflection angles. The engine wakes model consists of a series of closely spaced vortex rings with circular or elliptic cross sections. The rings are normal to a wake centerline which is free to move vertically and laterally to accommodate the local flow field beneath the wing and flaps. The two potential flow models are used in an iterative fashion to calculate the wing-flap loading distribution including the influence of the waves from up to two turbofan engines on the semispan. The method is limited to the condition where the flow and geometry of the configurations are symmetric about the vertical plane containing the wing root chord. The calculation procedure starts with arbitrarily positioned wake centerlines and the iterative calculation continues until the total configuration loading converges within a prescribed tolerance. Program results include total configuration forces and moments, individual lifting-surface load distributions, including pressure distributions, individual flap hinge moments, and flow field calculation at arbitrary field points.

  13. Peroneal artery perforator chimeric flap: changing the perspective in free fibula flap use in complex oromandibular reconstruction.

    PubMed

    Daya, Mahendra

    2008-08-01

    The fibula osteoseptocutaneous flap has undergone multiple refinements since its first description in oromandibular reconstruction. There is now a better understanding of the blood supply to the skin of the lateral aspect of the leg. Multiple free skin paddles can be harvested freestyle from the lateral aspect of the leg. The size of the flaps that can be harvested has not been clearly defined. A case report of a complex oromandibular reconstruction following a shotgun injury to the face demonstrates a way of maximizing the skin harvest. An osteoseptocutaneous fibula flap was used for the replacement of the mandible and the internal lining of the oral cavity. A larger lateral leg flap based on a musculocutaneous perforator of the peroneal artery was used for the external and full-thickness lower-lip defect. The latter flap by definition is a peroneal artery perforator flap, which to the best of my knowledge is terminology that has not been used in the English literature. The main purpose of this article is to review the blood supply of the lateral leg and how this can be utilized to reach the goals of a complex oromandibular and total lower-lip reconstruction.

  14. 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.

  15. Extended Anterolateral Thigh Flaps for Reconstruction of Extensive Defects of the Foot and Ankle

    PubMed Central

    Liu, Lifeng; Cao, Xuexin; Zou, Lin; Li, Zongyu; Cao, Xuecheng; Cai, Jinfang

    2013-01-01

    The anterolateral thigh flap has been used for coverage of defects in the foot and ankle for years. Conventional extended anterolateral thigh flaps do not undergo thinning procedures, which limit their application. Here, a clinical series of 24 patients is reported in which extended anterolateral thigh flaps were used for posttraumatic foot and ankle reconstruction. Of the 24 flaps, 14 were simple extended anterolateral thigh fasciocutaneous flaps and 10 were thinned extended anterolateral thigh flaps. One artery and two veins, including a superficial vein and an accompanying vein, were anastomosed to vascularize each flap. Follow-up of the 24 patients ranged from 10 months to 4 years postoperatively. All 24 flaps survived successfully, except one case that had partial flap necrosis distally due to excessive thinning. The cutaneous flap territory ranged from 250 cm2 to 400 cm2 (mean, 297 cm2). Only one patient received a debulking procedure. No ulceration occurred in any of the flaps due to contact with the shoe. The extended anterolateral thigh flap is a good alternative for extensive soft tissue defects of the foot and ankle. This study also supports the high reliability and excellent vascular supply of moderate thinned extended ALT flaps. PMID:24376731

  16. The use of visible light spectroscopy to measure tissue oxygenation in free flap reconstruction.

    PubMed

    Cornejo, Agustin; Rodriguez, Thomas; Steigelman, Megan; Stephenson, Stacy; Sahar, David; Cohn, Stephen M; Michalek, Joel E; Wang, Howard T

    2011-09-01

    The loss of a free flap is a feared complication for both the surgeon and the patient. Early recognition of vascular compromise has been shown to provide the best chance for flap salvage. The ideal monitoring technique for perioperative free flap ischemia would be noninvasive, continuous, and reliable. Visible light spectroscopy (VLS) was evaluated as a new method for predicting ischemia in microvascular cutaneous soft tissue free flaps. In an Institutional Review Board-approved prospective trial, 12 patients were monitored after free flap reconstructions. The tissue hemoglobin oxygen saturation (StO (2)) and total hemoglobin concentration (THB) of 12 flaps were continuously monitored using VLS for 72 hours postoperatively. Out of these 12 flaps 11 were transplanted successfully and 1 flap loss occurred. The StO (2 )was 48.99% and the THB was 46.74% for the 12 flaps. There was no significant difference in these values among the flaps. For the single flap loss, the device accurately reflected the ischemic drop in StO (2) indicating drastic tissue ischemia at 6 hours postoperatively before the disappearance of implantable Doppler signals or clinical signs of flap compromise. VLS, a continuous, noninvasive, and localized method to monitor oxygenation, appeared to predict early ischemic complications after free flap reconstruction.

  17. 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.

  18. Management of complications and compromised free flaps following major head and neck surgery.

    PubMed

    Kucur, Cuneyt; Durmus, Kasim; Uysal, Ismail O; Old, Matthew; Agrawal, Amit; Arshad, Hassan; Teknos, Theodoros N; Ozer, Enver

    2016-01-01

    Microvascular free flaps are preferred for most major head and neck reconstruction surgeries because of better functional outcomes, improved esthetics, and generally higher success rates. Numerous studies have investigated measures to prevent flap loss, but few have evaluated the optimal treatment for free flap complications. This study aimed to determine the complication rate after free flap reconstructions and discusses our management strategies. Medical records of 260 consecutive patients who underwent free flap reconstructions for head and neck defects between July 2006 and June 2010 were retrospectively reviewed for patient and surgical characteristics and postoperative complications. The results revealed that microvascular free flaps were extremely reliable, with a 3.5 % incidence of flap failure. There were 78 surgical site complications. The most common complication was neck wound infection, followed by dehiscence, vascular congestion, abscess, flap necrosis, hematoma, osteoradionecrosis, and brisk bleeding. Twenty patients with poor wound healing received hyperbaric oxygen therapy, which was ineffective in three patients who eventually experienced complete flap loss. Eleven patients with vascular congestion underwent medicinal leech therapy, which was effective. Among the 78 patients with complications, 44 required repeat surgery, which was performed for postoperative brisk bleeding in three. Eventually, ten patients experienced partial flap loss and nine experienced complete flap loss, with the latter requiring subsequent pectoralis major flap reconstruction. Microvascular free flap reconstruction represents an essential and reliable technique for head and neck defects and allows surgeons to perform radical resection with satisfactory functional results and acceptable complication rates.

  19. Women's Experiences With Flap Failure After Autologous Breast Reconstruction: A Qualitative Analysis.

    PubMed

    Higgins, Kristen S; Gillis, Joshua; Williams, Jason G; LeBlanc, Martin; Bezuhly, Michael; Chorney, Jill M

    2016-10-06

    Clinical experience suggests that flap failure after autologous breast reconstruction can be a devastating experience for women. Previous research has examined women's experiences with autologous breast reconstruction with and without complications, and patients' experiences with suboptimal outcomes from other medical procedures. The authors aimed to examine the psychosocial experience of flap failure from the patient's perspective. Seven women who had experienced unilateral flap failure after deep inferior epigastric perforator flap surgery in the past 12 years completed semistructured interviews about their breast cancer treatments, their experiences with flap failure, the impact of flap failure on their lives, and the coping strategies they used. Interpretive phenomenological analysis, a type of qualitative analysis that provides an in-depth account of participant's experiences and their meanings, was used to analyze the interview data. From these data, patient-derived recommendations were developed for surgeons caring for women who have experienced flap failure. Three main themes (6 subthemes) emerged: coming to terms with flap failure (coping with emotions, body dissatisfaction); making meaning of flap failure experience (questioning, relationship with surgeon); and care providers acknowledging the emotional experience of flap failure (experience of being treated "mechanically," suggestions for improvement). In conclusion, flap failure in breast reconstruction is an emotionally difficult experience for women. Although there are similarities to other populations of patients experiencing suboptimal outcomes from medical procedures, there are also unique aspects of the flap failure experience. A better understanding of women's experiences with flap failure will assist in providing more appropriate supports.

  20. Perfusion and Oxygenation of Random Advancement Skin Flaps Depend More on the Length and Thickness of the Flap Than on the Width to Length Ratio

    PubMed Central

    Memarzadeh, Khashayar; Sheikh, Rafi; Blohmé, Jonas; Torbrand, Christian

    2016-01-01

    Objective: The aim was to investigate the relationship between the dimensions (length, width, and thickness) of random advancement skin flaps and retained tissue perfusion and oxygenation. Methods: Flaps were raised on the flanks of pigs. The flaps were either 0.5 or 1.0 cm wide, thin (dissected halfway through the subcutaneous tissue) or thick (dissected down to the muscle fascia). Tissue perfusion was measured by laser Doppler velocimetry, and tissue oxygenation (pO2) was measured using a Licox system, every 0.5 cm along the flaps’ length. Tissue temperature was visualized by high-resolution infrared camera. Results: Perfusion and oxygenation decreased gradually from the base to the tip of the flap, reaching approximately 40% of presurgical values (2.0 cm) and approximately 20% (2.5 cm) from the base of the flap. There was virtually no blood flow, nor oxygen tension, 3.0 cm from the base of the flap. The width to length ratio of the flap did not determine blood flow or oxygenation, being approximately 30% in a 0.5 cm wide and 2 cm long flap, and 0% in a 1.0 cm wide and 4 cm long flap, both with a width to length ratio of 1:4. Blood flow and oxygenation were preserved to a greater extent in the thick flaps (∼40%) than in the thin flaps (∼20%), in a 0.5 cm wide and 2 cm long flap. Conclusions: The dissection of a random advancement flap results in hypoperfusion and oxygenation that cannot be predicted by the width to length ratio but depend on the length and thickness of the flap. PMID:26958105

  1. Novel Biomarkers of Arterial and Venous Ischemia in Microvascular Flaps

    PubMed Central

    Nguyen, Gerard K.; Monahan, John F. W.; Davis, Gabrielle B.; Lee, Yong Suk; Ragina, Neli P.; Wang, Charles; Zhou, Zhao Y.; Hong, Young Kwon; Spivak, Ryan M.; Wong, Alex K.

    2013-01-01

    The field of reconstructive microsurgery is experiencing tremendous growth, as evidenced by recent advances in face and hand transplantation, lower limb salvage after trauma, and breast reconstruction. Common to all of these procedures is the creation of a nutrient vascular supply by microsurgical anastomosis between a single artery and vein. Complications related to occluded arterial inflow and obstructed venous outflow are not uncommon, and can result in irreversible tissue injury, necrosis, and flap loss. At times, these complications are challenging to clinically determine. Since early intervention with return to the operating room to re-establish arterial inflow or venous outflow is key to flap salvage, the accurate diagnosis of early stage complications is essential. To date, there are no biochemical markers or serum assays that can predict these complications. In this study, we utilized a rat model of flap ischemia in order to identify the transcriptional signatures of venous congestion and arterial ischemia. We found that the critical ischemia time for the superficial inferior epigastric fasciocutaneus flap was four hours and therefore performed detailed analyses at this time point. Histolgical analysis confirmed significant differences between arterial and venous ischemia. The transcriptome of ischemic, congested, and control flap tissues was deciphered by performing Affymetrix microarray analysis and verified by qRT-PCR. Principal component analysis revealed that arterial ischemia and venous congestion were characterized by distinct transcriptomes. Arterial ischemia and venous congestion was characterized by 408 and 1536>2-fold differentially expressed genes, respectively. qRT-PCR was used to identify five candidate genes Prol1, Muc1, Fcnb, Il1b, and Vcsa1 to serve as biomarkers for flap failure in both arterial ischemia and venous congestion. Our data suggests that Prol1 and Vcsa1 may be specific indicators of venous congestion and allow clinicians to

  2. Versatility of nasolabial flaps in oral cavity reconstructions

    PubMed Central

    Cebrián-Carretero, José L.; Morán-Soto, María J.; Burgueño-García, Miguel

    2014-01-01

    Objectives: Describe the techniques involved and the results obtained witn nasolabial flaps in small and medium-sized defects of the oral cavity. The procedure is an easy resconstructive option with a high success rate and with very good aesthetic and functional outcomes. Study Design: A retrospective analysis of 16 nasolabial flap reconstructions in 15 oncological patients with oral cavity defects undergoing single-stage surgical interventions. We evaluate the tumor type, its location, size, the resective and reconstructive techniques involved, as well as any complications. Results: Out of 15 patients, 9 were male and 6 female, with ages ranging from 60-85 years. The primary tumor was located in the mandibular or maxillary gingiva in 7 patients, the lateral margin of the tongue in 5, the floor of the mouth in 3 and the mandibular symphysis in a single patient. The tumors were of a small to medium size. All patients underwent intraoral resections. In most cases, a cervical dissection was performed. All flaps were completed as single-stage surgical interventions, with 14 unilateral and 2 bilateral procedures. Five patients had received radiotherapy treatment for previous tumors. During the follow up period, which ranged from 4 months to 8 years, only one patient required their flap to be thinned, there were two incidents of surgical wound dehiscence, two hematomas and one orocutaneous fistula, none of which affected the survival of the flap. Conclusions: The nasolabial flap proves highly versatile in oral cavity reconstructions, coupled with a minimal morbidity of the donor region and good aesthetic and functional results. Its high vascularity allows for cervical dissections to be carried out or even for radiotherapy to be administered prior to it. It is straightforward, safe, and carrying it out as a single-stage intervention makes it the ideal surgical option for small to medium intraoral defects in edentulous patients with other comorbidities. Key words

  3. A systematic review of anterolateral thigh flap donor site morbidity

    PubMed Central

    Collins, Jessica; Ayeni, Olubimpe; Thoma, Achilleas

    2012-01-01

    PURPOSE: The anterolateral thigh (ALT) flap is widely used in reconstruction. Its advantage over other flaps is its purported minimal donor site morbidity. The present systematic review summarizes the types of complications and their incidence with this flap. A secondary objective is to delineate factors that influence these complications and make recommendations to avoid them. METHOD: Two independent assessors undertook a systematic review of the literature using multiple databases. All patients with ALT flap reconstruction for any defect were included. Donor site complications including lateral thigh paresthesia, musculoskeletal dysfunction, hypertrophic scarring, wound breakdown, infection, donor site pain, seroma, hematoma, compartment syndrome and muscle necrosis were extracted from identified articles and tabulated. Based on the number of pooled events and the number of cases performed, an incidence rate was calculated. RESULTS: Forty-two relevant articles were identified that included 2324 flaps. Of the 2324 flaps, the majority were fasciocutaneous (n=737), and 1303 of the flaps were used in head and neck reconstruction. The incidence of complications were: lateral thigh paresthesia (24.0%); musculoskeletal dysfunction (4.8%); hypertrophic scarring or wound dehiscence (4.8%); donor site pain (3.3%); seroma (2.4%); infection (2.2%); hematoma (0.7%); compartment syndrome (0.09%); and partial muscle necrosis (0.09%). CONCLUSION: Lateral thigh paresthesia is the most common complication. Severe complications such as compartment syndrome and muscle necrosis can occur, but are rare. Preservation of the lateral cutaneous nerve of the thigh, femoral motor nerve branches and deep fascia decreases the risk of complications. The degree of vastus lateralis disruption did not show a significant impact on musculoskeletal dysfunction. PMID:23598761

  4. [Treatment and outcome of complications after free flap-plasty].

    PubMed

    Giunta, R; Geisweid, A; Lukas, B; Feller, A M

    2000-05-01

    Free tissue transplantation is a routine procedure in reconstructive surgery. Although a lot of free flap techniques have been described, the postoperative management of complications has gained only little interest. Nevertheless, complications of perfusion after free tissue transplantation are not rare and require a systematic approach. The aim of this study is to classify perfusion failures with a simple grading system prospectively on a large clinical series and to evaluate the results of treatment to improve management. In the past ten months, 70 consecutive free flaps have been performed. By the end of the operation, the operating surgeon gave a prognosis concerning the probability of a possible perfusion complication. Postoperative monitoring was done exclusively by clinical examination (colour, time for recapillarisation and bleeding after puncture). According to these parameters, arterial and venous insufficiencies have been classified into four grades. After recording type, time and treatment of a postoperative complication, the result of treatment was rated subjectively and a cause was noted when possible. The final result was classified either as total flap loss, partial flap loss or successful tissue transplantation. A total of 28 (40%) complications, which were treated with an average of 2.1 options, were recorded. The ratio between arterial and venous failure was 15:13. In 21 cases surgical intervention became necessary (intraoperative n = 12, postoperative n = 9). The arising complication was diagnosed correctly in nine cases by the operating surgeon. In ten cases, the cause of the complication remained unclear. In 18 cases, the complication was treated successfully without any flap loss. In six cases partial flap loss was observed and in four cases a total flap loss had to be accepted. Our results confirm that only few objective criteria for treatment options with perfusion failures after free tissue transplantation exist. Nevertheless, the

  5. Flap reconstruction of the hypopharynx: a defect orientated approach.

    PubMed

    van der Putten, L; Spasiano, R; de Bree, R; Bertino, G; Leemans, C René; Benazzo, M

    2012-10-01

    The present retrospective analysis evaluated the outcomes of different flap reconstructions for several hypopharyngeal defects in 136 patients who underwent hypopharyngeal reconstruction with a free or pedicled flap after excision of pharyngeal or laryngeal carcinoma.Functional and oncological outcome were the main measures. Nine patients had a type I-a hypopharyngeal defect (partial with larynx preserved), 33 type I-b (partial without larynx preserved), 85 type II (circumferential), 5 type III (extensive superior) and 4 vertical hemipharyngolaryngectomy. The flaps used to reconstruct these defects were pectoralis major (n = 34), free radial forearm (n = 25), jejunum (n = 72), pedicled latissimus dorsi (n = 2), sternocleidomastoid (n = 1), lateral thigh (n = 1) and deltopectoral (n = 1). Twelve defects (9%) needed a secondary flap reconstruction. Surgical and medical complications were seen in 29% and 8% of patients, respectively; 18% of patients developed a fistula. No difference in complication rate or admission days was found for pre-operative versus no previous radiotherapy, type of defect or free versus pedicled flap. After 12 months follow-up, 38% of patients had a tracheo-oesophageal voice prosthesis, in 82% a fully oral diet was obtained and the average body weight gain was 0.9 kg. Five-year overall and disease-specific survival rates were 35% and 49%, respectively, while local and regional control rates were 65% and 91%, respectively. Considering these results, a defect orientated approach may be helpful for deciding which flap should be used for reconstruction of the hypopharynx. An algorithm is proposed with similar functional and oncological outcomes for the different groups. The choice of flap should be based on expected morbidity and functional outcome.

  6. 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.

  7. ``Schooling'' of wing pairs in flapping flight

    NASA Astrophysics Data System (ADS)

    Ramananarivo, Sophie; Zhang, Jun; Ristroph, Leif; AML, Courant Collaboration; Physics NYU Collaboration

    2015-11-01

    The experimental setup implements two independent flapping wings swimming in tandem. Both are driven with the same prescribed vertical heaving motion, but the horizontal motion is free, which means that the swimmers can take up any relative position and forward speed. Experiments show however clearly coordinated motions, where the pair of wings `crystallize' into specific stable arrangements. The follower wing locks into the path of the leader, adopting its speed, and with a separation distance that takes on one of several discrete values. By systematically varying the kinematics and wing size, we show that the set of stable spacings is dictated by the wavelength of the periodic wake structure. The forces maintaining the pair cohesion are characterized by applying an external force to the follower to perturb it away from the `stable wells'. These results show that hydrodynamics alone is sufficient to induce cohesive and coordinated collective locomotion through a fluid, and we discuss the hypothesis that fish schools and bird flocks also represent stable modes of motion.

  8. Why Do Elephants Flap Their Ears?

    NASA Astrophysics Data System (ADS)

    Koffi, Moise; Jiji, Latif; Andreopoulos, Yiannis

    2009-11-01

    It is estimated that a 4200 kg elephant generates as much as 5.12 kW of heat. How the elephant dissipates its metabolic heat and regulates its body temperature has been investigated during the past seven decades. Findings and conclusions differ sharply. The high rate of metabolic heat coupled with low surface area to volume ratio and the absence of sweat glands eliminate surface convection as the primary mechanism for heat removal. Noting that the elephant ears have high surface area to volume ratio and an extensive vascular network, ear flapping is thought to be the principal thermoregulatory mechanism. A computational and experimental program is carried out to examine flow and heat transfer characteristics. The ear is modeled as a uniformly heated oscillating rectangular plate. Our computational work involves a three-dimensional time dependent CFD code with heat transfer capabilities to obtain predictions of the flow field and surface temperature distributions. This information was used to design an experimental setup with a uniformly heated plate of size 0.2m x 0.3m oscillating at 1.6 cycles per second. Results show that surface temperature increases and reaches a steady periodic oscillation after a period of transient oscillation. The role of the vortices shed off the plate in heat transfer enhancement will be discussed.

  9. Theoretical studies on flapped delta wings

    NASA Technical Reports Server (NTRS)

    Oh, S.; Tavella, D.; Roberts, L.

    1988-01-01

    The effects of leading edge flaps on the aerodynamic characteristics of a low aspect-ratio delta wing are studied theoretically. As an extension of the classical crossflow plane analysis and in order to include separated shear layers, an analogy between three dimensional steady conical and two dimensional unsteady self-similar flows is explored. This analogy provides a simple steady-unsteady relationship. The criteria for the validity of the steady-unsteady analogy are also examined. Two different theoretical techniques are used to represent the separated shear layers based on the steady-unsteady analogy, neglecting the trailing edge effect. In the first approach, each vortex system is represented by a pair of concentrated vortices connected to the separation points by straight feeding sheets. In the second approach, the vortex cloud method is adopted for simulating the flow field in the crossflow plane. The separated shear layers are replaced with a cloud of discrete vortices and the boundary element method is employed to represent the wing trace by a vorticity distribution. A simple merging scheme is used to model the core region of the vortical flow as a single vortex by imposing a restriction on the shear layer rotation angle. The results are compared with experiments and with results from 3-D panel calculations.

  10. Rotor Flapping Response to Active Control

    NASA Technical Reports Server (NTRS)

    Nguyen, Khanh; Johnson, Wayne

    2004-01-01

    Rotor active control using higher harmonic blade pitch has been proposed as a means to reduce both rotor radiated noise and airframe vibration and to enhance rotor performance. The higher harmonic input, however, can affect rotor thrust and cyclic flapping - the basic trim characteristics of the rotor. Some of the trim changes can negate the active control benefits. For example, wind tunnel test results of a full scale BO-105 rotor with individual-blade control indicate some rotor performance improvements, accompanied with changes in rotor trim, using two-per-rev blade pitch input. The observed performance benefits could therefore be a simple manifestation of the trim change rather than an efficient redistribution of the rotor airloads. More recently, the flight test of the BO-105 helicopter equip,ped with individual-blade-control actuators also reported trim changes whenever the two-per-rev blade pitch for noise reduction was activated. The pilot had to adjust the trim control to maintain the aircraft under a constant flight path. These two cases highlight the, importance of trim considerations in the application of active control to rotorcraft.

  11. The supraclavicular artery island and trapezius myocutaneous flaps in head and neck reconstruction.

    PubMed

    Ramirez, Carlos A; Fernandes, Rui P

    2014-08-01

    The supraclavicular artery island flap can be readily used to reconstruct defects within the neck, parotid, lateral temporal region, and lower third of the face. Benefits of the supraclavicular flap include good color and texture match, an ease of harvest, and minimal donor site morbidity; there is also no significant post-operative monitoring required. The trapezius muscle serves as a source for multiple myocutaneous flaps of which most are considered to be salvage flaps among head and neck reconstructive surgeons.

  12. Immediate Bilateral Breast Reconstruction with Unilateral Deep Superior Epigastric Artery and Superficial Circumflex Iliac Artery Flaps

    PubMed Central

    Hansen, Keith S.; Hartman, Brett C.; Sood, Rajiv; Socas, Juan

    2016-01-01

    Autologous breast reconstruction utilizing a perforator flap is an increasingly popular method for reducing donor site morbidity and implant-related complications. However, aberrant anatomy not readily visible on computed tomography angiography is a rare albeit real risk when undergoing perforator flap reconstruction. We present an operative case of a patient who successfully underwent a bilateral breast reconstruction sourced from a unilateral abdominal flap divided into deep superior epigastric artery and superficial circumflex iliac artery flap segments. PMID:27689054

  13. 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

  14. Effect of flap deflection on the lift coefficient of wings operating in a biplane configuration

    NASA Technical Reports Server (NTRS)

    Stasiak, J.

    1977-01-01

    Biplane models with a lift flap were tested in a wind tunnel to study the effect of flap deflection on the aerodynamic coefficient of the biplane as well as of the individual wings. Optimization of the position flap was carried out, and the effect of changes in the chord length of the lower wing was determined for the aerodynamic structure of a biplane with a lift flap on the upper wing.

  15. Supraclavicular artery perforator flap in management of post-burn neck reconstruction: clinical experience.

    PubMed

    Ismail, H; Elshobaky, A

    2016-09-30

    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.

  16. Free craniotomy versus osteoplastic craniotomy, assessment of flap viability using 99mTC MDP SPECT.

    PubMed

    Shelef, Ilan; Golan, Haim; Merkin, Vladimir; Melamed, Israel; Benifla, Mony

    2016-09-01

    There are currently two accepted neurosurgical methods to perform a bony flap. In an osteoplastic flap, the flap is attached to surrounding muscle. In a free flap, the flap is not attached to adjacent tissues. The former is less common due to its complexity and the extensive time required for the surgery; yet the rate of infection is significantly lower, a clear explanation for which is unknown. The objective of this study was to test the hypothesis that the osteoplastic flap acts as a live implant that resumes its blood flow and metabolic activity; contrasting with the free flap, which does not have sufficient blood flow, and therefore acts as a foreign body. Seven patients who underwent craniotomy with osteoplastic flaps and five with free flaps had planar bone and single photon emission computed tomography (SPECT) scans of the skull at 3-7days postoperative, after injection of the radioisotope, 99m-technetium-methylene diphosphonate (99m-Tc-MDP). We compared radioactive uptake as a measure of metabolic activity between osteoplastic and free flaps. Mean normalized radioactive uptakes in the centers of the flaps, calculated as the ratios of uptakes in the flap centers to uptakes in normal contralateral bone, were [mean: 1.7 (SD: 0.8)] and [0.6 (0.1)] for the osteoplastic and free flap groups respectively and were [2.4 (0.8)] and [1.3 (0.4)] in the borders of the flaps. Our analyses suggest that in craniotomy, the use of an osteoplastic flap, in contrast to free flap, retains bone viability.

  17. Efficiency of an auto-propelled flapping airfoil

    NASA Astrophysics Data System (ADS)

    Benkherouf, T.; Mekadem, M.; Oualli, H.; Hanchi, S.; Keirsbulck, L.; Labraga, L.

    2011-05-01

    The present study deals with an investigation of the flow aerodynamic characteristics and the propulsive velocity of a system equipped with a nature inspired propulsion system. In particular, the study is aimed at studying the effect of the flapping frequency on the flow behavior. We consider a NACA0014 airfoil undergoing a vertical sinusoidal flapping motion. In contrast to nearly all previous studies in the literature, the present work does not impose any velocity on the inlet flow. During each iteration the outer flow velocity is computed after having determined the forces exerted on the airfoil. Forward motion may only be produced by flapping motion of the airfoil. This is more consistent with the physical phenomenon. The non-stationary viscous flow around the flapping airfoil is simulated using Ansys-Fluent 12.0.7. The airfoil movement is achieved using the deformable mesh technique and an in-house developed User Define Function (UDF). Our results show the influence of flapping frequency and amplitude on both the airfoil velocity and the propulsive efficiency. The resulting motion is contrasts to the applied forces. In the present study, the frequency ranges from 0.1 to 20 Hz while the airfoil amplitude values considered are: 10%, 17.5%, 25% and 40%.

  18. Rotation flaps for coverage after total knee arthroplasty

    PubMed Central

    Pozzobon, Leonardo Rafael; Helito, Camilo Partezani; Guimarães, Tales Mollica; Gobbi, Riccardo Gomes; Pécora, José Ricardo; Camanho, Gilberto Luis

    2013-01-01

    OBJECTIVE: To evaluate the results obtained using local myocutaneous rotation flaps in cases of wound dehiscence after total knee arthroplasty. METHODS: Patients undergoing these surgical procedures were selected in the 2000-2012 period. The nine selected cases during this period were subjected to flap coverage due to skin dehiscence associated with infection. In eight cases we used rotation flaps of the medial gastrocnemius, and in one case we used advancing skin. RESULTS: Eighty nine percent of the cases were successful in the coverage of the prosthesis and the viability of the flaps. In four cases it was possible to maintain or review the prosthesis. Four other cases progressed to amputation due to failure on treatment of infections, and one case remained without the prosthesis. The functional evaluation showed an unsatisfactory outcome in 89% of cases. CONCLUSION: Coverage flaps are a good option for the treatment of cases of dehiscence with exposure of the prosthesis and the functional failure was associated with the inability to control the infection and the damage it caused. Level of Evidence IV, Case Series. PMID:24453672

  19. Functional Reconstruction of Sarcoma Defects Utilising Innervated Free Flaps

    PubMed Central

    Grinsell, Damien; Di Bella, Claudia; Choong, Peter F. M.

    2012-01-01

    Soft-tissue reconstruction following preoperative radiotherapy and wide resection of soft tissue sarcoma remains a challenge. Pedicled and free tissue transfers are an essential part of limb sparing surgery. We report 22 cases of sarcoma treated with radiotherapy and wide excision followed by one-stage innervated free or pedicled musculocutaneous flap transfers. The resection involved the upper limb in 3 cases, the lower limb in 17, and the abdominal wall in 2. The flaps used for the reconstruction were mainly latissimus dorsi and gracilis. The range of motion was restored fully in 14 patients. The muscle strength of the compartment reconstructed was of grades 4 and 5 in all patients except one. The overall function was excellent in all the cases with functional scores of 71.2% in the upper limb and 84% in the lower limb. The only 2 major complications were flap necrosis, both revised with another flap, one of which was innervated with restoration of function. Innervated flaps are valuable alternatives for reconstruction after sarcoma resection in the extremity and in the abdominal wall. The excellent functional results are encouraging, and we believe that innervated muscle reconstruction should be encouraged in the treatment of sarcoma after radiotherapy and wide resection. PMID:22969309

  20. Flexible flapping wings can exhibit quasi-periodic motion!

    NASA Astrophysics Data System (ADS)

    Bose, Chandan; Sarkar, Sunetra

    2016-10-01

    The dynamics of a flexible flapping wing is investigated by modelling it as a coupled nonlinear fluid-structure interaction (FSI) system in the low Reynolds number flow regime in accordance to the flight of flapping wing micro air vehicles (MAVs). A bifurcation analysis, by varying the free-stream wind velocity (U ∞) as the control parameter, revealed the presence of a new dynamics in the form of a quasi-periodic attractor in the flapping wing motion. The structural and aerodynamic nonlinearities present in the system cause a supercritical Hopf bifurcation, where stable limit cycle oscillation emerges from fixed point response beyond a critical value of the free-stream velocity. Further increasing the control parameter, another bifurcation named Neimark-Sacker bifurcation takes place and as a result, the flapping wing exhibits quasi-periodic motion. The presence of Neimark-Sacker bifurcation in the flapping flow-field dynamics is an interesting find and the present work focuses on it's associated dynamical behaviour. Various dynamical system tools like frequency spectra, phase space, Poincaré section, first return map have been implemented successfully to confirm the presence of quasi-periodicity.

  1. Tissue oxygen tension measurement for monitoring musculocutaneous and cutaneous flaps.

    PubMed

    Hjortdal, V E; Awwad, A M; Gottrup, F; Kirkegaard, L; Gellett, S

    1990-01-01

    In pigs, latissimus dorsi musculocutaneous island flaps and buttock skin island flaps were raised. Subcutaneous (PscO2) and intramuscular oxygen tension (PimO2) were measured using a non-heated needle electrode before, during and after repeated occlusion of the supplying artery or the draining vein. During arterial and venous occlusion, the tissue oxygen tension in the musculocutaneous flap dropped rapidly. A plateau was reached after 15 min. After arterial occlusion the mean value was 20 mmHg (SEM = +/- 5 mmHg, N = 6) in the subcutis and 16 mmHg in the muscle (SEM = +/- 4 mmHg, N = 10). After venous occlusion the mean value was 11 mmHg (SEM = +/- 3 mmHg, N = 6) in the subcutis. In the skin flap the drop of PscO2 was slower, and after 30 min of arterial occlusion the mean value was 29 mmHg (SEM = +/- 9 mmHg, N = 6). This study has shown that tissue oxygen tension measurement can be used as a sensitive indicator of acute impairment of the supplying vessels in island flaps. The method seems to have potential for monitoring free tissue transfers. A comparable decrease in PscO2 was found for arterial and venous impairment.

  2. Structural analysis of the PP2C phosphatase tPphA from Thermosynechococcus elongatus: a flexible flap subdomain controls access to the catalytic site.

    PubMed

    Schlicker, Christine; Fokina, Oleksandra; Kloft, Nicole; Grüne, Tim; Becker, Stefan; Sheldrick, George M; Forchhammer, Karl

    2008-02-15

    The homologue of the phosphoprotein PII phosphatase PphA from Thermosynechococcus elongatus, termed tPphA, was identified and its structure was resolved in two different space groups, C222(1) and P4(1)2(1)2, at a resolution of 1.28 and 3.05 A, respectively. tPphA belongs to a large and widely distributed subfamily of Mg(2+)/Mn(2+)-dependent phosphatases of the PPM superfamily characterized by the lack of catalytic and regulatory domains. The core structure of tPphA shows a high degree of similarity to the two PPM structures identified so far. In contrast to human PP2C, but similar to Mycobacterium tuberculosis phosphatase PstP, the catalytic centre exhibits a third metal ion in addition to the dinuclear metal centre universally conserved in all PPM members. The fact that the third metal is only liganded by amino acids, which are universally conserved in all PPM members, implies that the third metal could be general for all members of this family. As a specific feature of tPphA, a flexible subdomain, previously recognized as a flap domain, could be revealed. Comparison of different structural isomers of tPphA as well as site-specific mutagenesis implied that the flap domain is involved in substrate binding and catalytic activity. The structural arrangement of the flap domain was accompanied by a large side-chain movement of an Arg residue (Arg169) at the basis of the flap. Mutation of this residue strongly impaired protein stability as well as catalytic activity, emphasizing the importance of this amino acid for the regional polysterism of the flap subdomain and confirming the assumption that flap domain flexibility is involved in catalysis.

  3. Submental Perforator Flap Design with a Near-Infrared Fluorescence Imaging System: The Relation between Number of Perforators, Flap Perfusion, and Venous Drainage

    PubMed Central

    Matsui, Aya; Lee, Bernard T.; Winer, Joshua H.; Laurence, Rita G.; Frangioni, John V.

    2009-01-01

    Background The submental flap is a reliable alternative to microsurgical reconstruction of facial deformities, providing an excellent cosmetic match with the contour and color of the face. In this study, we evaluated submental flap design by employing near-infrared (NIR) fluorescence angiography to identify perforator arteries (PAs). The impact of the number of preserved PAs on flap perfusion and venous drainage were quantified. Methods Indocyanine green was injected intravenously into n = 18 pigs. Three groups of 6 animals each had one, two, or three PAs preserved. The FLARE™ NIR fluorescence imaging system was employed for image acquisition. Images were recorded before and after flap creation, and every h, for 6 h. The time to maximum perfusion, the drainage ratio (an indicator of venous drainage), and the percentage of perfused flap area were analyzed statistically at each time point. Results Flaps with a single dominant PA had an initial mean perfused area of 80%, which improved to 97% at 6 h. For flaps with two and three preserved PAs, perfused area at 6 h was 99.8% and 100%, respectively. A significant increase was observed in all three metrics as more vessels were preserved. Regardless of the number of PAs preserved, though, all three metrics improved over 6 h. Conclusions NIR fluorescence angiography can reliably identify submental PAs for flap design, and can be used to assess flap perfusion and venous drainage in real-time. Flap metrics at 6 h were equivalent when either one, or multiple PAs, were preserved. PMID:19935293

  4. The effect of early detection of anterolateral thigh free flap crisis on the salvage success rate, based on 10 years of experience and 1072 flaps.

    PubMed

    Yang, Q; Ren, Z H; Chickooree, D; Wu, H J; Tan, H Y; Wang, K; He, Z J; Gong, C J; Ram, V; Zhang, S

    2014-09-01

    The aim of this study was to assess the effectiveness of early exploration of anterolateral thigh (ALT) free flap compromise in head and neck reconstruction and to correlate this with the salvage success rate. The perioperative data of 1051 patients with 1072 ALT flap reconstructions were reviewed retrospectively for the period January 2002 to December 2012. Outcome measures included ethnicity, defect type, incidence and timing of flap compromise, type of flap compromise, causes of vascular occlusion, and salvage rate. The success rate of free flap reconstruction was 97.3% (1043/1072). Of the 29 failures, 21 were complete and eight were partial failures (10-40% of the flap). Venous occlusions occurred in 39 flaps (83.0%) and arterial occlusions in five flaps (17.0%). Six cases were detected within 8h postoperatively, 13 at 8-16 h postoperatively, seven at 16-24h postoperatively, and 18 at 24-48 h postoperatively, with respective salvage rates of 66.7%, 61.5%, 28.6%, and 22.2%; three cases detected after 48 h failed. The salvage rate at ≤16 h (62.2%) was much higher than that at >16 h (21.4%, P=0.0039). Early detection, re-exploration, and effective handling of the flap crisis increases the rate of flap salvage tremendously.

  5. Development of a value-added product using channel catfish belly flap meat

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The shank fillet of channel catfish is a primary product form produced during processing and is formed by trimming the belly flap or nugget section from a boneless fillet. Belly flap meat comprises around 20 percent of the fillet weight. Belly flap meat has a fat content of about 15 percent compared...

  6. My First 100 Consecutive Microvascular Free Flaps: Pearls and Lessons Learned in First Year of Practice

    PubMed Central

    2013-01-01

    Background: Microvascular reconstruction for oncologic defects is a challenging and rewarding endeavor, and successful outcomes are dependent on a multitude of factors. This study represents lessons learned from a personal prospective experience with 100 consecutive free flaps. Methods: All patients’ medical records were reviewed for demographics, operative notes, and complications. Results: Overall 100 flaps were performed in 84 consecutive patients for reconstruction of breast, head and neck, trunk, and extremity defects. Nineteen patients underwent free flap breast reconstruction with 10 patients undergoing bilateral reconstruction and 2 patients receiving a bipedicle flap for reconstruction of a unilateral breast defect. Sixty-five free flaps were performed in 61 patients with 3 patients receiving 2 free flaps for reconstruction of extensive head and neck defects and 1 patient who required a second flap for partial flap loss. Trunk and extremity reconstruction was less common with 2 free flaps performed in each group. Overall, 19 patients (22.6%) developed complications and 14 required a return to the operating room. There were no flap losses in this cohort. Thorough preoperative evaluation and workup, meticulous surgical technique and intraoperative planning, and diligent postoperative monitoring and prompt intervention are critical for flap success. Conclusions: As a young plastic surgeon embarking in reconstructive plastic surgery at an academic institution, the challenges and dilemmas presented in the first year of practice have been daunting but also represent opportunities for learning and improvement. Skills and knowledge acquired from time, experience, and mentors are invaluable in optimizing outcomes in microvascular free flap reconstruction. PMID:25289221

  7. Surgical exploration of 71 free flaps in crisis following head and neck reconstruction.

    PubMed

    Yang, X; Li, S; Wu, K; Hu, L; Liu, W; Ji, T; Hu, Y; Xu, L; Sun, J; Zhang, Z; Zhang, C

    2016-02-01

    The medical records of patients who had undergone a free flap reconstruction after radical resection of oral cancer between January 2009 and December 2013 at the study hospital in China were reviewed retrospectively. Of the 1550 patients who underwent free flap reconstructions, 71 were explored for suspected flap compromise caused by postoperative thrombosis. Patient demographic data, clinicopathological data of the tumour, details of the free flaps, and operative findings were assessed, and the medical records were analyzed to identify the reasons for intervention and the outcomes. Of the 71 flaps in crisis, 47 (66.2%) were salvaged. Free flap failure was 6.2-times more likely to develop in patients undergoing surgical exploration after 72 h (95% confidence interval 2.090-18.197, P=0.001). Of the 19 flaps identified as subject to delayed exploration, 14 failed and three had partial necrosis. Free flap failure was 3.4-times more likely to develop in patients with perforator flaps (95% confidence interval 1.222-9.719, P=0.019). The early detection of free flap failure is critical to flap salvage. The salvage success rate decreases significantly at >72 h after the initial operation. It appears to be more difficult to salvage a perforator flap.

  8. Assessment of skin flaps using optically based methods for measuring blood flow and oxygenation.

    PubMed

    Payette, Jeri R; Kohlenberg, Elicia; Leonardi, Lorenzo; Pabbies, Arone; Kerr, Paul; Liu, Kan-Zhi; Sowa, Michael G

    2005-02-01

    The objective of this study was to compare two noninvasive techniques, laser Doppler and optical spectroscopy, for monitoring hemodynamic changes in skin flaps. Animal models for assessing these changes in microvascular free flaps and pedicle flaps were investigated. A 2 x 3-cm free flap model based on the epigastric vein-artery pair and a reversed MacFarlane 3 x 10-cm pedicle flap model were used in this study. Animals were divided into four groups, with groups 1 (n = 6) and 2 (n = 4) undergoing epigastric free flap surgery and groups 3 (n = 3) and 4 (n = 10) undergoing pedicle flap surgery. Groups 1 and 4 served as controls for each of the flap models. Groups 2 and 3 served as ischemia-reperfusion models. Optical spectroscopy provides a measure of hemoglobin oxygen saturation and blood volume, and the laser Doppler method measures blood flow. Optical spectroscopy proved to be consistently more reliable in detecting problems with arterial in flow compared with laser Doppler assessments. When spectroscopy was used in an imaging configuration, oxygen saturation images of the entire flap were generated, thus creating a visual picture of global flap health. In both single-point and imaging modes the technique was sensitive to vessel manipulation, with the immediate post operative images providing an accurate prediction of eventual outcome. This series of skin flap studies suggests a potential role for optical spectroscopy and spectroscopic imaging in the clinical assessment of skin flaps.

  9. [Emergency free flap in reconstruction of the lower limb. Thirty-five years of experience].

    PubMed

    Bellidenty, L; Chastel, R; Pluvy, I; Pauchot, J; Tropet, Y

    2014-02-01

    Authors analyzed 89 cases (86 patients) of lower limb extensive soft tissue defects reconstruction during 1978 to 2013. The mean age is 37 years and 2 months old (range: 5-84 years old). A total of 71 males and 15 female were included. Free flaps were used in emergency in 23 cases for principally covering Gustilo 3B open lower limb fracture and in a later stage for 66 cases all referred from their center for coverage of exposed bone, with frequently osteomyelitis. About the selection of free flaps, in 47 cases we used a latissimus dorsi flaps, 12 cases of epiploon free transfer (in septic area), 10 cases of gracilis transfer and 10 serratus anterior flaps. There are one medial gastrocnemius flap, 2 composite soleus and fibular free flap, 2 antebrachial flap, one inguinal myoosteocutaneous flap, 1 transferred from the other lower limb and one inguinal cutaneous flap. There are 18 free flap losses: one in emergency and 17 after delayed reconstruction. Authors retrospectively analyzed the results (complications, osteomyelitis) according to the timing for lower extremity reconstruction. They found a low infection and flap failure rates (4%) when the coverage is made in the same operating time than initial fracture fixation, they increase to 60% for osteomyelitis and to 23% for flap failure when the reconstruction is delayed.

  10. Investigation of drag reduction through a flapping mechanism on circular cylinder

    NASA Astrophysics Data System (ADS)

    Asif, Md. Asafuddoula; Gupta, Avijit Das; Rana, M. D. Juwel; Ahmed, Dewan Hasan

    2016-07-01

    During flapping wing, a bird develops sufficient lift force as well as counteracts drag and increases its speed through different orientations of feathers on the flapping wings. Differently oriented feathers play a significant role in drag reduction during flying of a bird. With an objective to investigate the effect of installation of such flapping mechanism as a mean of drag reduction in case of flow over circular cylinder, this concept has been implemented through installation of continuous and mini flaps, made of MS sheet metal, where flaps are oriented at different angles as like feathers of flapping wings. The experiments are carried out in a subsonic wind tunnel. After validation and comparison with conventional result of drag analysis of a single cylinder, effects of flapping with Reynolds number variation, implementation of different orientations of mini flaps and variation of different interspacing distance between mini flaps are studied to find the most effective angle of attack of drag reduction on the body of circular cylinder. This research show that, installation of continuous flap reduces value of drag co-efficient, CD up to 66%, where as mini flaps are found more effective by reducing it up to 73%. Mini flaps of L/s=6.25, all angled at 30O, at the 30O angular position on the body of circular cylinder has been found the most effective angle of attack for drag reduction in case of flow over circular cylinder.

  11. Flap Decisions and Options in Soft Tissue Coverage of the Upper Limb

    PubMed Central

    Griffin, Michelle; Hindocha, Sandip; Malahias, Marco; Saleh, Mohamed; Juma, Ali

    2014-01-01

    Soft tissue deficiency in the upper limb is a common presentation following trauma, burns infection and tumour removal. Soft tissue coverage of the upper limb is a challenging problem for reconstructive surgeons to manage. The ultimate choice of soft tissue coverage will depend on the size and site of the wound, complexity of the injury, status of surrounding tissue, exposure of the vital structures and health status of the patient. There are several local cutaneous flaps that provide adequate soft tissue coverage for small sized defects of the hand, forearm and arm. When these flaps are limited in their mobility regional flaps and free flaps can be utilised. Free tissue transfer provides vascularised soft tissue coverage in addition to the transfer of bone, nerve and tendons. Careful consideration of free flap choice, meticulous intraoperative dissection and elevation accompanied by post-operative physiotherapy are required for successful outcomes for the patient. Several free flaps are available for reconstruction in the upper limb including the groin flap, anterolateral flap, radial forearm flap, lateral arm flap and scapular flap. In this review we will provide local, regional and free flap choice options for upper limb reconstruction, highlighting the benefits and challenges of different approaches. PMID:25408782

  12. Acute effects of cigarette smoke exposure on experimental skin flaps

    SciTech Connect

    Nolan, J.; Jenkins, R.A.; Kurihara, K.; Schultz, R.C.

    1985-04-01

    Random vascular patterned caudally based McFarlane-type skin flaps were elevated in groups of Fischer 344 rats. Groups of rats were then acutely exposed on an intermittent basis to smoke generated from well-characterized research filter cigarettes. Previously developed smoke inhalation exposure protocols were employed using a Maddox-ORNL inhalation exposure system. Rats that continued smoke exposure following surgery showed a significantly greater mean percent area of flap necrosis compared with sham-exposed groups or control groups not exposed. The possible pathogenesis of this observation as well as considerations and correlations with chronic human smokers are discussed. Increased risks of flap necrosis by smoking in the perioperative period are suggested by this study.

  13. Chaotic Dynamics of Flags from Recurring Values of Flapping Moment

    NASA Astrophysics Data System (ADS)

    Virot, Emmanuel; Faranda, Davide; Amandolese, Xavier; Hémon, Pascal

    The performance of recently proposed flag-based energy harvesters is strongly limited by the chaotic response of flags to strong winds. From an experimental point of view, the detection of flag chaotic dynamics were scarce, based on the flapping amplitude and the maximal Lyapunov exponent. In practice, tracking the flapping amplitude is difficult and flawed in the large oscillation limit. Also, computing the maximal Lyapunov exponent from time series of limited size requires strong assumptions on the attractor geometry, without getting insurance of their reliability. For bypassing these issues, (1) we use a time series which takes into account the whole dynamics of the flag, by using the flapping moment which integrates its displacements, and (2) we apply an algorithm of detection of chaos based on recurring values in time series.

  14. Computational Design of a Krueger Flap Targeting Conventional Slat Aerodynamics

    NASA Technical Reports Server (NTRS)

    Akaydin, H. Dogus; Housman, Jeffrey A.; Kiris, Cetin C.; Bahr, Christopher J.; Hutcheson, Florence V.

    2016-01-01

    In this study, we demonstrate the design of a Krueger flap as a substitute for a conventional slat in a high-lift system. This notional design, with the objective of matching equivalent-mission performance on aircraft approach, was required for a comparative aeroacoustic study with computational and experimental components. We generated a family of high-lift systems with Krueger flaps based on a set of design parameters. Then, we evaluated the high-lift systems using steady 2D RANS simulations to find a good match for the conventional slat, based on total lift coefficients in free-air. Finally, we evaluated the mean aerodynamics of the high-lift systems with Krueger flap and conventional slat as they were installed in an open-jet wind tunnel flow. The surface pressures predicted with the simulations agreed well with experimental results.

  15. Flapping dynamics of a flexible propulsor near ground

    NASA Astrophysics Data System (ADS)

    Ryu, Jaeha; Park, Sung Goon; Kim, Boyoung; Sung, Hyung Jin

    2016-12-01

    The flapping motion of a flexible propulsor near the ground was simulated using the immersed boundary method. The hydrodynamic benefits of the propulsor near the ground were explored by varying the heaving frequency ( St) of the leading edge of the flexible propulsor. Propulsion near the ground had some advantages in generating thrust and propelling faster than propulsion away from the ground. The mode analysis and flapping amplitude along the Lagrangian coordinate were examined to analyze the kinematics as a function of the ground proximity ( d) and St. The trailing edge amplitude (a_tail) and the net thrust (overline{{F}}_x) were influenced by St of the flexible propulsor. The vortical structures in the wake were analyzed for different flapping conditions.

  16. Interactions between butterfly scales and unsteady flows during flapping flight

    NASA Astrophysics Data System (ADS)

    Jones, Robert; Lang, Amy

    2008-11-01

    Recent research has shown that the highly flexible wings of butterflies in flapping flight develop vortices along their leading and trailing edges. Butterfly scales (approximately 100 microns) have a shingled pattern and extend into the boundary layer. These scales could play a part in controlling separation in this 3-dimensional complex flow field. Biomimetic applications of butterfly scales may aid in the development of flapping wing micro air vehicles. In this study, we observed that the orientation of the scales may relate to the local flow field, and might move or shift during flight. Monarch butterflies were trained to fly in a low speed smoke tunnel for visualization. Scales were removed from the leading and trailing edges and specimens were photographed at 500 frames per second. Variation in flapping pattern and flight fitness are discussed.

  17. Arterialized venous free flap for reconstruction of burned face.

    PubMed

    Iglesias, Martín; Butrón, Patricia; Chávez-Muñoz, Claudia; Ramos-Sánchez, Iván; Barajas-Olivas, Alexandra

    2008-01-01

    In this study, a forearm arterialized venous free flap (23 cm x 14 cm) was used in a 25-year-old male with facial burns sequels to reconstruct both cheeks, chin, lips, nose, columnella, nasal tip, and nostrils. It was arterialized by the facial artery to an afferent vein anastomosis. The venous flow was drained by four efferent vein to vein anastomoses. Although it developed small inferior marginal necrosis in the lower lip, the rest of the flap survived with good quality of the skin in both texture and color, with self-delimitation of the different esthetics units of the center of the face such as the nasogenian folds, nostrils, and upper lip filtrum, without the need of additional thinning surgical procedures. From all of the above, the arterialized venous free flap is an alternative reconstructive option for the treatment of burn sequels especially those that include the centrofacial region.

  18. Chord-wise Tip Actuation on Flexible Flapping Plates

    NASA Astrophysics Data System (ADS)

    Martin, Nathan; Gharib, Morteza

    2015-11-01

    The aerodynamic characteristics of low aspect ratio flapping plates are strongly influenced by the interaction between tip and edge vortices. This has led to the development of tip actuation mechanisms which bend the tip towards the root of the plate in the span-wise direction during oscillation to investigate its impact. In our current work, a tip actuation mechanism to bend a flat plate's two free corners towards one another in the chord-wise direction is developed using a shape memory alloy. The aerodynamic forces and resulting flow field are investigated from dynamically altering the tip chord-wise curvature while flapping. The frequency of oscillation, stroke angle, flexibility, and tip actuation timing are independently varied to determine their individual effects. These results will further the fundamental understanding of flapping wing aerodynamics. This material is based upon work supported by the National Science Foundation Graduate Research Fellowship under Grant No. DGE 1144469.

  19. Detached Eddy Simulation of Flap Side-Edge Flow

    NASA Technical Reports Server (NTRS)

    Balakrishnan, Shankar K.; Shariff, Karim R.

    2016-01-01

    Detached Eddy Simulation (DES) of flap side-edge flow was performed with a wing and half-span flap configuration used in previous experimental and numerical studies. The focus of the study is the unsteady flow features responsible for the production of far-field noise. The simulation was performed at a Reynolds number (based on the main wing chord) of 3.7 million. Reynolds Averaged Navier-Stokes (RANS) simulations were performed as a precursor to the DES. The results of these precursor simulations match previous experimental and RANS results closely. Although the present DES simulations have not reached statistical stationary yet, some unsteady features of the developing flap side-edge flowfield are presented. In the final paper it is expected that statistically stationary results will be presented including comparisons of surface pressure spectra with experimental data.

  20. Flap Side-Edge Noise: Acoustic Analysis of Sen's Model

    NASA Technical Reports Server (NTRS)

    Hardin, Jay C.; Martin, James E.

    1996-01-01

    The two-dimensional flap side-edge flow model developed by Sen is analyzed to reveal the noise production potential of the proposed mechanism. The model assumes that a vortex will form at the equilibrium position off the side edge of the flap. The vortex is then perturbed away from the equilibrium position by incoming turbulence causing it to oscillate and thus radiate sound. The noise field is calculated three-dimensionally by taking the flap to have a finite chord. Spectra and directivity of the farfield sound are presented. In addition, the effect of retarded time differences is evaluated. The parameters in the model are related to typical aircraft parameters and noise reduction possibilities are proposed.

  1. Transitions in the wake of a flapping foil.

    PubMed

    Godoy-Diana, Ramiro; Aider, Jean-Luc; Wesfreid, José Eduardo

    2008-01-01

    We study experimentally the vortex streets produced by a flapping foil in a hydrodynamic tunnel, using two-dimensional particle image velocimetry. An analysis in terms of a flapping frequency-amplitude phase space allows the identification of (i) the transition from the well-known Bénard-von Kármán (BvK) wake to the reverse BvK vortex street that characterizes propulsive wakes, and (ii) the symmetry breaking of this reverse BvK pattern giving rise to an asymmetric wake. We also show that the transition from a BvK wake to a reverse BvK wake precedes the actual drag-thrust transition and we discuss the significance of the present results in the analysis of flapping systems in nature.

  2. Statins: a new pharmacological agent for free flap surgery?

    PubMed

    Karsenti, Guillaume; Le Manach, Yannick; Bouvier, Stéphanie; Chaine, André; Bertolus, Chloé

    2010-05-01

    Microvascular free tissue transfer has become the standard for reconstruction in head and neck oncological surgery. Several pharmacological agents have been used in order to increase the success rate of this surgery, but there is currently no consensus for an ideal drug. We review the literature concerning the complications encountered in free flap surgery related to the ischaemia-reperfusion injury and detail the effects of statins relevant to this endothelial dysfunction. Statins, because of their pleiotropic effects such as preservation of vascular tone, anticoagulation and anti-inflammatory properties, appear to be useful in free flap surgery. This study highlights the benefits of statins in order to increase the success rate and the quality of the free flap. They should be included in the perioperative strategy, especially in patients with cardiovascular risk factors. A protocol is presented.

  3. Hyperbaric oxygen (HBO2) treatment for a failing facial flap.

    PubMed

    McCrary, Brian F

    2007-01-01

    Hyperbaric oxygen (HBO2) is an approved treatment for 13 pathological entities. One of these indications--a failing facial flap--is presented in this case report of a traumatic wound to the face and right axilla after an unprovoked pit bull attack on a 4 year old girl. Surgical repair was started acutely but the facial flap became congested and ischaemic, indicating deterioration of the blood supply. HBO2 treatments were initiated twice a day, resulting in remarkably decreased swelling and discomfort after the first treatment. Leeching was also used to assist with reduction of venous congestion in the flap. The patient was discharged 5 days later with a well perfused, mostly intact, incision with minimal tenderness. Surgical repair was required for a small area of wound dehiscence. Photographs documenting the patient's progress with HBO2 are presented. A discussion of the mechanisms of action of HBO2 and its beneficial effects is provided in this case.

  4. Efficient flapping flight using flexible wings oscillating at resonance

    NASA Astrophysics Data System (ADS)

    Alexeev, Alexander; Masoud, Hassan

    2010-11-01

    Using a fully-coupled computational approach that integrates the lattice Boltzmann and lattice spring models, we investigate the three-dimensional aerodynamics of flexible flapping wings at resonance. The wings are tilted from the horizontal and oscillate vertically driven by a force applied at the wing root. Our simulations reveal that resonance oscillations drastically enhance the aerodynamic efficiency of low-Reynolds-number plunging, and yield lift and lift-to-weight ratio comparable to the values typical for small insects. Within the resonance band, we identify two flapping regimes leading to the maximum lift and the maximum efficiency, which are characterized by different bending modes of flexible flapping wings. Our results indicate the feasibility of using flexible wings driven by a simple harmonic stroke for designing efficient microscale flying machines.

  5. Paradoxical effects of heme arginate on survival of myocutaneous flaps

    PubMed Central

    Czopek, Alicja; Wigmore, Stephen J.; Kluth, David C.

    2013-01-01

    Ischemia reperfusion injury (IRI) contributes to partial flap and solid organ transplant failure. Heme-oxygenase 1 (HO-1) is an inducible, cytoprotective enzyme which protects against IRI in solid organ transplant models. Heme arginate (HA), a HO-1 inducer, is a promising, translatable, preconditioning agent. This study investigated the effects of preconditioning with HA on the clinical outcome of a myocutaneous IRI model. Forty male Lewis rats were randomized to intravenously receive 1) Control-NaCl, 2) HA, 3) HA and tin mesoporphyrin (SnMP), a HO-1 inhibitor; and 4) SnMP alone. Twenty-four hours later, an in situ transverse rectus abdominis myocutaneous flap was performed under isoflurane anesthesia. Viability of flaps was measured clinically and by laser-Doppler perfusion scanning. In vitro work on human epidermal keratinocytes (HEKa) assessed the effects of HA, SnMP, and the iron chelator desferrioxamine on 1) cytotoxicity, 2) intracellular reactive oxygen species (ROS) concentration, and 3) ROS-mediated DNA damage. In contrast to our hypothesis, HA preconditioning produced over 30% more flap necrosis at 48 h compared with controls (P = 0.02). HA-containing treatments produced significantly worse flap perfusion at all postoperative time points. In vitro work showed that HA is cytotoxic to keratinocytes. This cytotoxicity was independent of HO-1 and was mediated by the generation of ROS by free heme. In contrast to solid organ data, pharmacological preconditioning with HA significantly worsened clinical outcome, thus indicating that this is not a viable approach in free flap research. PMID:24089372

  6. Free anterolateral thigh flaps for upper extremity soft tissue reconstruction

    PubMed Central

    Spindler, Nick; Al-Benna, Sammy; Ring, Andrej; Homann, Heinz; Steinsträsser, Lars; Steinau, Hans-Ulrich; Langer, Stefan

    2015-01-01

    Introduction: Limb-threatening wounds of the upper extremity pose a challenge to the micro vascular surgeon. The aim of this study is to analyze the outcome of free anterolateral thigh flaps for upper extremity soft tissue reconstruction. Methods: A retrospective review of patients undergoing this procedure from 2005 to 2012 was performed. Case note analysis was performed to determine demographic and perioperative factors, and complications and outcomes. Results: Thirty-two patients with a mean age of 53 years (9–84 yrs) underwent upper extremity reconstruction with an anterolateral thigh (ALT) flap. There were 24 (75%) males and 8 (25%) females. The etiology of the soft tissue defects was: infection (44.6%); post-tumor ablation (40%); and trauma (15.6%). The defect site was most commonly in the forearm (53.1%), followed by the elbow (12.5 %), arm (12.5%) and hand (21.9%). The mean timing of free flap transfer was 6.8 days after admission to our institution (minimum 1 days, maximum 9 days). Mean operative time of surgery was 4 h 39 min (minimum 3 h 2 min, maximum 6 h 20 min). The mean hospitalization was 24.8 days (minimum 5, maximum 85). The ALT success rate was at 92.3%. Partial flap necrosis was documented in five cases (15.6%). Complete flap loss occurred in two post-traumatic cases who both lost their limbs. Discussion: This flap, in the hands of experienced surgeons, provides reliable coverage of upper extremity defects. PMID:26504734

  7. Aeroelastic Airworthiness Assesment of the Adaptive Compliant Trailing Edge Flaps

    NASA Technical Reports Server (NTRS)

    Herrera, Claudia Y.; Spivey, Natalie D.; Lung, Shun-fat; Ervin, Gregory; Flick, Peter

    2015-01-01

    The Adaptive Compliant Trailing Edge (ACTE) demonstrator is a joint task under the National Aeronautics and Space Administration Environmentally Responsible Aviation Project in partnership with the Air Force Research Laboratory and FlexSys, Inc. (Ann Arbor, Michigan). The project goal is to develop advanced technologies that enable environmentally friendly aircraft, such as adaptive compliant technologies. The ACTE demonstrator flight-test program encompassed replacing the Fowler flaps on the SubsoniC Aircraft Testbed, a modified Gulfstream III (Gulfstream Aerospace, Savannah, Georgia) aircraft, with control surfaces developed by FlexSys. The control surfaces developed by FlexSys are a pair of uniquely-designed unconventional flaps to be used as lifting surfaces during flight-testing to validate their structural effectiveness. The unconventional flaps required a multidisciplinary airworthiness assessment to prove they could withstand the prescribed flight envelope. Several challenges were posed due to the large deflections experienced by the structure, requiring non-linear analysis methods. The aeroelastic assessment necessitated both conventional and extensive testing and analysis methods. A series of ground vibration tests (GVTs) were conducted to provide modal characteristics to validate and update finite element models (FEMs) used for the flutter analyses for a subset of the various flight configurations. Numerous FEMs were developed using data from FlexSys and the ground tests. The flap FEMs were then attached to the aircraft model to generate a combined FEM that could be analyzed for aeroelastic instabilities. The aeroelastic analysis results showed the combined system of aircraft and flaps were predicted to have the required flutter margin to successfully demonstrate the adaptive compliant technology. This paper documents the details of the aeroelastic airworthiness assessment described, including the ground testing and analyses, and subsequent flight

  8. Scalp Rotation Flap for Reconstruction of Complex Soft Tissue Defects.

    PubMed

    Costa, Dary J; Walen, Scott; Varvares, Mark; Walker, Ronald

    2016-02-01

    Importance Scalp reconstructions may be required after tumor resection or trauma. The inherent anatomy of the scalp presents challenges and may limit reconstructive options. Objective To describe and investigate the scalp rotation flap as a reconstructive technique for complex soft tissue defects. Design Retrospective case series with a mean follow-up of 13 months. Setting Tertiary academic center. Participants A total of 22 patients with large scalp soft tissue defects undergoing scalp rotation flap reconstruction. Interventions The flap is designed adjacent to the defect and elevated in the subgaleal plane. The flap is rotated into the defect, and a split-thickness skin graft is placed over the donor site periosteum. Main Outcomes and Measure Data points collected included defect size, operative time, hospital stay, and patient satisfaction with cosmetic outcome. Results Mean patient age was 71 years. Mean American Society of Anesthesiologist classification was 2.8. Mean defect size was 41 cm(2) (range: 7.8-120 cm(2)), and 19 of 22 defects resulted from a neoplasm resection. Mean operative time was 181 minutes, and mean hospital stay was 2.4 days. There were no intraoperative complications. Three patients with previous radiation therapy had distal flap necrosis. Twenty-one patients (95%) reported an acceptable cosmetic result. Conclusions and Relevance The scalp rotation flap is an efficient and reliable option for reconstructing complex soft tissue defects. This can be particularly important in patients with significant medical comorbidities who cannot tolerate a lengthy operative procedure.

  9. Hyperbaric Oxygen Therapy for the Compromised Graft or Flap

    PubMed Central

    Francis, Ashish; Baynosa, Richard C.

    2017-01-01

    Significance: Tissue grafts and flaps are used to reconstruct wounds from trauma, chronic disease, tumor extirpation, burns, and infection. Despite careful surgical planning and execution, reconstructive failure can occur due to poor wound beds, radiation, random flap necrosis, vascular insufficiency, or ischemia–reperfusion (IR). Traumatic avulsions and amputated composite tissues—compromised tissue—may fail from crush injury and excessively large sizes. While never intended, these complications result in tissue loss, additional surgery, accrued costs, and negative psychosocial patient effects. Recent Advances: Hyperbaric oxygen (HBO) has demonstrated utility in the salvage of compromised grafts/flaps. It can increase the likelihood and effective size of composite graft survival, improve skin graft outcomes, and enhance flap survival. Mechanisms underlying these beneficial effects include increased oxygenation, improved fibroblast function, neovascularization, and amelioration of IR injury. Critical Issues: Common strategies for the compromised graft or flap include local wound care, surgical debridement, and repeated reconstruction. These modalities are associated with added costs, time, need for reoperation, morbidity, and psychosocial effects. Preservation of the amputated/avulsed tissues minimizes morbidity and maximizes the reconstructive outcome by salvaging the compromised tissue and obviating additional surgery. HBO is often overlooked as a potential tool that can limit these issues. Future Directions: Animal studies demonstrate a benefit of HBO in the treatment of compromised tissues. Clinical studies support these findings, but are limited to case reports and series. Further research is needed to provide multicenter prospective clinical studies and cost analyses comparing HBO to other adjunctive therapies in the treatment of compromised grafts/flaps. PMID:28116225

  10. Hand Allograft Saved by an Ultrathin Groin Flap

    PubMed Central

    Château, Joseph; Gazarian, Aram; Boucher, Fabien; Badet, Lionel; Braye, Fabienne; Saint-Cyr, Michel

    2016-01-01

    Summary: We report a case of a young double-hand allotransplant patient who presented with a full-thickness skin necrosis of the dorsum of the left hand after vascular compromise of the allotransplantation. Considering the lack of viable dorsal tissue overlying the extensor tendons and the need for early hand rehabilitation, an ultrathin pedicled groin flap was used for the coverage. This procedure resulted in salvaging the allotransplantation, and the patient was able to successfully return to work after his surgery. To our knowledge, this is the only case of an upper extremity allotransplant salvaged by a pedicled flap. PMID:27757334

  11. Experimental study of flapping jets in a soap film

    NASA Astrophysics Data System (ADS)

    Lee, Julia; Kim, Ildoo; Mandre, Shreyas

    2015-11-01

    Plateau and Rayleigh's observation and explanation on jet instability have inspired us over the years and there has been a significant advance in understanding the jet dynamics. Here, we present a quasi-two-dimensional experimental study of flapping jets in a soap film. Newtonian and non-Newtonian solutions are injected in a flowing soap film. Thinning, break-ups, and beads-on-a-string of the jets, and axisymmetric vortices shredded from the flapping jets are visualized. We employ PIV of the flow motion around the jets to gain an understanding of the roles of instabilities in the flow.

  12. Unsteady wake measurements of an oscillating flap at transonic speeds

    NASA Technical Reports Server (NTRS)

    Bodapati, S.; Lee, C.-S.

    1984-01-01

    The steady and unsteady wake profiles of an airfoil with an oscillating flap were measured at nominal free stream Mach number of 0.8 in the NASA Ames 11 x 11-foot wind tunnel. The instantaneous wake velocity and pressure profiles at four axial locations are presented up to one chord length from the trailing edge. Both fundamental harmonic frequency and typical time history data are presented to observe the effects of airfoil incidence and flap angle. The drag coefficient obtained from the wake pressure measurements is compared with that obtained from the airfoil pressure distribution.

  13. Stability and control of externally blown flap configurations

    NASA Technical Reports Server (NTRS)

    Parlett, L. P.

    1972-01-01

    The results of wind-tunnel investigations on the stability and control characteristics of externally blown jet-flap configurations are presented. Conventional wind-tunnel tests and free-flight model tests have shown that longitudinal trim and stability can be achieved by a properly located horizontal tail of sufficient size, and that lateral trim in the engine-out condition can be produced by combinations of differential flap, spoiler, and rudder deflection. Free-flight model tests have revealed a lightly damped Dutch roll lateral oscillation, and have shown that the oscillation can be stabilized by use of artificial damping.

  14. Periosteal Pedicle Flap Harvested during Vestibular Extension for Root Coverage

    PubMed Central

    Kumar, Shubham; Gupta, Krishna Kumar; Agrawal, Rahul; Srivastava, Pratima; Soni, Shalabh

    2015-01-01

    Root exposure along with inadequate vestibular depth is a common clinical finding. Treatment option includes many techniques to treat such defects for obtaining predictable root coverage. Normally, the vestibular depth is increased first followed by a second surgery for root coverage. The present case report describes a single-stage technique for vestibular extension and root coverage in a single tooth by using the Periosteal Pedicle Flap (PPF). This technique involves no donor site morbidity and allows for reflection of sufficient amount of periosteal flap tissue with its own blood supply at the surgical site, thus increasing the chances of success of root coverage with simultaneous increase in vestibular depth. PMID:26788377

  15. 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.

  16. A case of nonisland pedicled foot fillet flap for below-knee amputation stump wound: treatment option for compartment syndrome after fibular free flap surgery.

    PubMed

    Hwang, Jae Ha; Kim, Kwang Seog; Lee, Sam Yong

    2014-02-01

    Despite the frequent use of the fibular free flap, there have been no reports of severe compartment syndrome of the donor leg that necessitated limb amputation. A 66-yr-old man had a fibular osseous free flap transfer from the left leg to the mandible that was complicated by postoperative compartment syndrome. An extensive chronic leg wound resulted, which was treated with multiple debridements and finally with below-knee amputation. Successful coverage of the below-knee amputation stump was accomplished with a nonisland pedicled foot fillet flap. Various foot fillet flaps may be used acutely as a free or an island pedicled flap, but dissection of the vascular pedicle may be difficult in a chronically inflamed wound because of inflammation and adhesions to surrounding tissue. The nonisland pedicled foot fillet flap may be considered as a useful option for treatment of a chronically inflamed stump wound after below-knee amputation.

  17. A new skin flap method for total auricular reconstruction in microtia patients with a reconstructed ear canal: extended scalp and extended mastoid postauricular skin flaps.

    PubMed

    Hwang, Euna; Kim, Young Soo; Chung, Seum

    2014-06-01

    Before visiting a plastic surgeon, some microtia patients may undergo canaloplasty for hearing improvement. In such cases, scarred tissues and the reconstructed external auditory canal in the postauricular area may cause a significant limitation in using the posterior auricular skin flap for ear reconstruction. In this article, we present a new method for auricular reconstruction in microtia patients with previous canaloplasty. By dividing a postauricular skin flap into an upper scalp extended skin flap and a lower mastoid extended skin flap at the level of a reconstructed external auditory canal, the entire anterior surface of the auricular framework can be covered with the two extended postauricular skin flaps. The reconstructed ear shows good color match and texture, with the entire anterior surface of the reconstructed ear being resurfaced with the skin flaps. Clinical question/level of evidence; therapeutic level IV.

  18. Proteins.

    ERIC Educational Resources Information Center

    Doolittle, Russell F.

    1985-01-01

    Examines proteins which give rise to structure and, by virtue of selective binding to other molecules, make genes. Binding sites, amino acids, protein evolution, and molecular paleontology are discussed. Work with encoding segments of deoxyribonucleic acid (exons) and noncoding stretches (introns) provides new information for hypotheses. (DH)

  19. Span load distribution for tapered wings with partial-span flaps

    NASA Technical Reports Server (NTRS)

    Pearson, H A

    1937-01-01

    Tables are given for determining the load distribution of tapered wings with partial-span flaps placed either at the center or at the wing tips. Seventy-two wing-flap combinations, including two aspect ratios, four taper ratios, and nine flap lengths, are included. The distributions for the flapped wing are divided into two parts, one a zero lift distribution due primarily to the flaps and the other an additional lift distribution due to an angle of attack of the wing as a whole. Comparison between theoretical and experimental results for wings indicate that the theory may be used to predict the load distribution with sufficient accuracy for structural purposes.

  20. Total lower eyelid reconstruction with superficial temporal fascia flap and porous polyethylene implant: a case report.

    PubMed

    Sahin, Ismail; Aykan, Andac; Acikel, Cengiz; Alhan, Dogan; Isik, Selcuk

    2012-01-01

    Total reconstruction of the eyelid after serious periorbital injury is a challenging procedure for plastic and reconstructive surgery. Although several methods have been used for reconstructing the eyelids, such as advancement flap with fascia lata sling, island mucochrondrocutaneous flap, prefabricated temporal island flap, porous polyethylene and superficial temporal fascia flap, creating a supportive eyelid for housing an artificial eye without complication is still an ongoing problem. In the case presented, superficial temporal fascia flap with porous polyethylene was used for the reconstruction of total lower eyelid.

  1. Reconstruction of the chin using an expanded deltopectoral flap following multiple recurrences of oral cancer

    PubMed Central

    Balakrishnan, Chenicheri; Hackenson, David; Balakrishnan, Anila; Elliott, David; Careaga, Daniel

    2012-01-01

    An important alternative to free tissue transfer in patients requiring correction of soft tissue chin defects are local and regional flaps, such as the pectoralis major myocutaneous flap and deltopectoral flap. With predictable vascular supply, potential for large size, and good aesthetic match for facial and cervical skin, the deltopectoral flap can offer the reconstructive surgeon additional options in patients who lack vessels suitable for free tissue transfer. The use of an expanded deltopectoral flap for a staged reconstruction of the chin in a patient with cancer recurrences, concomitant resections, radiation and multiple reconstructions is reported. PMID:23997595

  2. The combined free partial vastus lateralis with anterolateral thigh perforator flap reconstruction of extensive composite defects.

    PubMed

    Posch, N A S; Mureau, M A M; Flood, S J; Hofer, S O P

    2005-12-01

    Myocutaneous (MC) free flaps are useful for many reconstructive indications. Perforator flaps have become standard of care. The anterolateral thigh flap (ALT) donor site is popular. With the ALT flap varying sizes of vastus lateralis (VL) muscle can be harvested as a MC flap. The skin islands of these flaps have a great range of freedom when dissected on their perforator. It was hypothesised that the VL-ALT perforator flap would offer adequate tissue volume combining maximal freedom in planning with minimal donor site morbidity. From November 2001 to February 2003 a free partial VL with ALT perforator flap was used in 11 patients to reconstruct large defects. Indications for adding a muscular component were exposed bone, skull base, (artificial) dura, or osteosynthesis material, open sinuses, and lack of muscular bulk. Flaps were planned as standard ALT flaps, after which three types of dissection were performed: I. true MC flap; II. muscle flap with a skin island on one perforator, which could be rotated up to 180 degrees ; III. chimera skin perforator flap with muscle being harvested on a separate branch from the source vessel or on a side branch of the skin perforator. Mean skin size of the MC-ALT flaps was 131 cm2. Mean muscle part size of the MC-ALT flaps was 268 cm3. Muscular parts were custom designed for all defects. No total or partial flap failures were seen. Colour mismatch was seen in 6 of 8 patients, when skin was used in the facial area in this all white population. Excessive flap bulk was found in 8 of 11 patients at 6 weeks, however, only in 2 of 11 patients after 6 months. Patients were satisfied with the functional result (8 of 11 patients) as well as the cosmetic result of their reconstruction (7 of 11 patients). All less satisfied patients had received their flap for external facial skin reconstruction. Donor site morbidity was minimal. The combined free partial VL with ALT perforator flap proved valuable as a (chimera type) MC flap with maximal

  3. Expanded thoracoacromial artery perforator flap for reconstruction of full-perioral scar contracture.

    PubMed

    Wang, Qianwen; Wang, Jiaqi

    2015-03-01

    Various types of anterior chest flaps can be recruited in the reconstruction of faciocervical region. Most of them were created based on the internal mammary artery and the lateral thoracic artery, and the thoracoacromial artery (TAA) is usually used in pectoralis major musculocutaneous flap. An anterior chest flap with TAA perforator (TAAP) will have no sacrifice of the pectoralis major muscle, but less reports, especially expanded pedicled one, can be reviewed. Here, we reported a case using expanded pedicled TAAP flap to reconstruct the perioral scar contracture. In this technique, expanded TAAP flap could be easily harvested without the sophisticated microsurgical technology. Acceptable esthetic and functional results were achieved.

  4. Ischemic Tissue Injury in the Dorsal Skinfold Chamber of the Mouse: A Skin Flap Model to Investigate Acute Persistent Ischemia

    PubMed Central

    Harder, Yves; Schmauss, Daniel; Wettstein, Reto; Egaña, José T.; Weiss, Fabian; Weinzierl, Andrea; Schuldt, Anna; Machens, Hans-Günther; Menger, Michael D.; Rezaeian, Farid

    2014-01-01

    Despite profound expertise and advanced surgical techniques, ischemia-induced complications ranging from wound breakdown to extensive tissue necrosis are still occurring, particularly in reconstructive flap surgery. Multiple experimental flap models have been developed to analyze underlying causes and mechanisms and to investigate treatment strategies to prevent ischemic complications. The limiting factor of most models is the lacking possibility to directly and repetitively visualize microvascular architecture and hemodynamics. The goal of the protocol was to present a well-established mouse model affiliating these before mentioned lacking elements. Harder et al. have developed a model of a musculocutaneous flap with a random perfusion pattern that undergoes acute persistent ischemia and results in ~50% necrosis after 10 days if kept untreated. With the aid of intravital epi-fluorescence microscopy, this chamber model allows repetitive visualization of morphology and hemodynamics in different regions of interest over time. Associated processes such as apoptosis, inflammation, microvascular leakage and angiogenesis can be investigated and correlated to immunohistochemical and molecular protein assays. To date, the model has proven feasibility and reproducibility in several published experimental studies investigating the effect of pre-, peri- and postconditioning of ischemically challenged tissue. PMID:25489743

  5. Prevention of unfavourable effects of cigarette smoke on flap viability using botulinum toxin in random pattern flaps: An experimental study

    PubMed Central

    Karayel, Hikmet; Kaya, Burak; Caydere, Muzaffer; Terzioğlu, Ahmet; Aslan, Gürcan

    2015-01-01

    BACKGROUND: There are numerous clinical and experimental studies reporting unfavourable effects of cigarette smoke on skin flaps. OBJECTIVE: To investigate whether unfavourable effects of cigarette smoke on flap survival could be reduced by botulinum toxin type A. METHODS: Twenty-eight male Wistar albino rats (15 months of age, mean weight 210 g [range 180 g to 230 g]) were included. They were divided into four groups of seven animals each. The control group underwent the surgical procedure alone. Surgical procedure was performed after administration of botulinum toxin type A in the botulinum toxin (BTX) group, after exposure to cigarette smoke in the cigarette smoke (CS) group, and after BTX type A administration and exposure to CS in the CS+BTX (CS+BTX) group. Random pattern cutaneous flaps (3 cm × 9 cm) were elevated from the dorsum of all rats. Necrosis area was calculated in percentages (%) using Image J computer software. Tissue samples were examined histopathologically. RESULTS: The mean necrotic area in the control group (26%) and in the BTX group (21%) were similar (P=0.497), whereas administration of BTX type A significantly decreased flap necrosis area in the rats exposed to CS (the mean necrosis areas were 41.5% in the CS group, and 26% in the CS+BTX group; P<0.001). Histopathological examination findings corroborated the unfavourable effects of CS and preventive effects of BTX type A. CONCLUSION: Preoperative administration of BTX significantly enhanced flap viability in the rats exposed to CS. Further human studies are warranted to verify whether BTX type A could be used as an agent to reduce the risk of flap necrosis in patients who smoke. PMID:26361625

  6. Effects of Buflomedil and Pentoxifylline on Hamster Skin-Flap Microcirculation: Prediction of Flap Viability Using Orthogonal Polarization Spectral Imaging

    PubMed Central

    Coelho da Mota, Denise Salles; Furtado, Eliane; Bottino, Daniel Alexandre; Bouskela, Eliete

    2009-01-01

    OBJECTIVE This study investigated the effects of buflomedil and pentoxifylline, both of which are used in reconstructive surgery of hamster skin flap microcirculation, and evaluated the skin flap survival rate by orthogonal polarization spectral imaging. METHOD Twenty-four adult male Syrian golden hamsters were divided into three groups: a control (C, 0.1 ml 0.9% saline), buflomedil (B, 3 mg/kg/day), and pentoxifylline group (P, 14.5 mg/kg/day). Treatments administered intraperitoneally were initiated 1 hour before skin flap preparation and continued for 7 days post-operatively at 12-hour intervals. Preparations (skin flaps) were divided into 12 fields, which were organized into six bands. Functional capillary density (FCD, in mm/mm2), distance from the skin flap base to blood flow cessation (Distwith flow, in cm), percentage of viable skin (VA, in%), and qualitative analysis of blood flow by orthogonal polarization spectral imaging were performed at 1 and 24 hours and on the seventh post-operative day. RESULT Bands IV, V, and VI presented no flow independent of time. The functional capillary density group B was higher than that of groups C and P, primarily after 24 hours. All groups showed an increase in D with time but reached similar final distances (C = 2.73, B = 2.78 and P = 2.70 cm). Moreover, the percentage of viable areas remained at approximately 50%. The orthogonal polarization spectral imaging was useful to assess viability by counting fields with and without blood flow. CONCLUSIONS Functional capillary density values were higher in the buflomedil group compared to the control and pentoxifylline groups in this model. Functional capillary density did not influence D or the percentage of VA, and the technique showed favorable potential to assess/predict the viability of skin flaps within 1 h after surgery. PMID:19690666

  7. Incisions for cochlear implant flaps and superficial skin temperature. Skin temperature/blood circulation in CI flaps.

    PubMed

    Pau, Hans Wilhelm; Sievert, Uwe; Graumüller, Sylke; Wild, Ernst

    2004-01-01

    Healing and integration of a cochlear implant is largely influenced by good blood circulation in the covering skin, which, on the other hand, is closely correlated to skin temperature. Measuring superficial flap temperatures by thermography is an easy way to get some clues about the corresponding blood supply. These data should allow some implications for the design of skin flaps in cochlear implant surgery. In 15 patients thermography was carried out prior to and after cochlear implantation, using the Agema 550 Thermovision system. It was evident, that the anatomic courses of the major superficial arteries were represented by areas of increased temperature. The pattern of temperature distribution may allow some conclusions concerning site and shape of surgical incisions. From our data we concluded, that most types of incisions do not interfere too much with the arterial blood supply. However, some types like the extended retroauricular C-incision may eventually cause problems. Our data suggest, that the straight or slightly curved vertical retroauricular incision causes the least impairment of blood circulation. After surgery, directly along the incisions (and later along the scars) temperature was diminished, indicating reduced blood circulation. In our series, the thickness of the implant did not impede blood circulation significantly. So far, we could not examine patients with local circulation disorders. Probably local scars, skin atrophies, angiopathies etc. may present typical patterns of temperature distribution, which require individual design of skin flaps. Thermography is an easy method which can give impressions of local blood circulation in skin flaps. If the courses of the major arteries and their branches are respected, blood circulation within the flap should not be problematic. Thermography is likely to help designing optimal flaps in cases with impeded blood circulation e.g. by pre-existing scar formations.

  8. Development of a Wind Turbine Test Rig and Rotor for Trailing Edge Flap Investigation: Static Flap Angles Case

    NASA Astrophysics Data System (ADS)

    Abdelrahman, Ahmed; Johnson, David A.

    2014-06-01

    One of the strategies used to improve performance and increase the life-span of wind turbines is active flow control. It involves the modification of the aerodynamic characteristics of a wind turbine blade by means of moveable aerodynamic control surfaces. Trailing edge flaps are relatively small moveable control surfaces placed at the trailing edge of a blade's airfoil that modify the lift of a blade or airfoil section. An instrumented wind turbine test rig and rotor were specifically developed to enable a wide-range of experiments to investigate the potential of trailing edge flaps as an active control technique. A modular blade based on the S833 airfoil was designed to allow accurate instrumentation and customizable settings. The blade is 1.7 meters long, had a constant 178mm chord and a 6° pitch. The modular aerodynamic parts were 3D printed using plastic PC-ABS material. The blade design point was within the range of wind velocities in the available large test facility. The wind facility is a large open jet wind tunnel with a maximum velocity of 11m/s in the test area. The capability of the developed system was demonstrated through an initial study of the effect of stationary trailing edge flaps on blade load and performance. The investigation focused on measuring the changes in flapwise bending moment and power production for different trailing edge flap spanwise locations and deflection angles. The relationship between the load reduction and deflection angle was linear as expected from theory and the highest reduction was caused by the flap furthest from the rotor center. Overall, the experimental setup proved to be effective in measuring small changes in flapwise bending moment within the wind turbine blade and will provide insight when (active) flap control is targeted.

  9. A Novel Method to Estimate the Weight of the DIEP Flap in Breast Reconstruction: DIEP-W, a Simple Calculation Formula Using Paraumbilical Flap Thickness.

    PubMed

    Woo, Kyong-Je; Kim, Eun-Ji; Lee, Kyeong-Tae; Mun, Goo-Hyun

    2016-09-01

    Background Preoperative estimation of abdominal flap volume is valuable for breast reconstruction, especially in lean patients. The purpose of this study was to develop a formula to estimate the weight of the deep inferior epigastric artery perforator (DIEP) flap using unidimensional parameters. Methods We retrospectively collected data on 100 consecutive patients who underwent breast reconstruction using the DIEP flap. Multiple linear regression analysis was used to develop a formula to estimate the weight of the flap. Predictor variables included body mass index, height of the flap, width of the flap, and flap thickness on computed tomography angiographic images at three paraumbilical sites: 5 cm right, left, and inferior from the umbilicus. Then we prospectively tested the accuracy of the developed formula in 38 consecutive patients who underwent breast reconstruction with free DIEP flaps. Results A calculation formula and a smartphone application, DIEP-W was developed from retrospective analysis (R (2) = 92.7%, p < 0.001). In the prospective study, the average estimated weight was 96.3% of the actual weight, giving the formula a mean absolute percentage error of 7.7% (average differences of 45 g). The flap size in the prospective group was significantly smaller (p < 0.001) and donor-site complications were less (p = 0.002) than those of retrospective group. Conclusion Surgeons can easily calculate the DIEP weight with varying flap dimensions in a real-time fashion using this formula during preoperative planning and intraoperative design. Estimating the flap weight facilitates economical use of the flap, which can lead to reduced donor-site complications.

  10. Flap monitoring by transcutaneous PO2 and PCO2: importance of transcutaneous PCO2 in determining follow-up treatment for compromised free flaps.

    PubMed

    Hashimoto, Ichiro; Nakanishi, Hideki; Takiwaki, Hirotsugu; Takase, Maki Toda; Yamano, Masahiro; Sedo, Hiromichi

    2007-07-01

    The authors conducted a two-part study to determine whether transcutaneous oxygen pressure (TcPO (2)) and transcutaneous carbon dioxide pressure (TcPCO (2)) can be used to monitor flap viability after transplantation. The first part was an animal study in which TcPO (2) and TcPCO (2) were measured in 10 epigastric island flaps subjected to arterial or venous ischemia. The second part was a clinical study in which both were measured in 27 free skin flaps. In the experimental study, TcPO (2) decreased to nearly 0 mmHg after 10 minutes of arterial and venous ischemia. TcPCO (2) increased to 100 mmHg after 60 minutes of either type of ischemia. In the clinical study, congestion was suspected in six flaps on the basis of clinical signs alone. Three congested flaps with TcPCO (2) more than 90 mmHg were selected for intervention. The remaining three congested flaps, with TcPCO (2) 80 mmHg or less, survived completely without further treatment. The TcPO (2) of all treated flaps and of the six flaps not requiring further treatment was 0 mmHg. Results of experimental study indicate that TcPO (2) is more sensitive than TcPCO (2) to flap ischemia. However, results of clinical study suggest that it is very hard to distinguish congested flaps from healthy flaps by TcPO (2) alone. The authors believe that a congested flap with a TcPCO (2) more than 90 mmHg requires further treatment.

  11. A Simple Strategy in Avulsion Flap Injury: Prediction of Flap Viability Using Wood's Lamp Illumination and Resurfacing with a Full-thickness Skin Graft

    PubMed Central

    Lim, Hyoseob; Han, Dae Hee; Lee, Il Jae

    2014-01-01

    Background Extensive degloving injuries of the extremities usually result in necrosis of the flap, necessitating comprehensive skin grafting. Provided there is a sufficient tool to evaluate flap viability, full-thickness skin can be used from a nonviable avulsed flap. We used a Wood's lamp to determine the viability of avulsed flaps in the operation field after intravenous injection of fluorescein dye. Methods We experienced 13 cases during 16 months. Fifteen minutes after the intravenous injection of fluorescein dye, the avulsed skin flaps were examined and non-fluorescent areas were marked under Wood's lamp illumination. The marked area was defatted for full-thickness skin grafting. The fluorescent areas were sutured directly without tension. The non-fluorescent areas were covered by defatted skin. Several days later, there was soft tissue necrosis within the flap area. We measured necrotic area and revised the flap. Results Among all the cases, necrotic area was 21.3% of the total avulsed area. However, if we exclude three cases, one of a carelessly managed patient and two cases of the flaps were inappropriately applied, good results were obtained, with a necrotic area of only 8.4%. Eight patients needed split-thickness skin grafts, and heel pad reconstruction was performed with free flap. Conclusions A full-thickness skin graft from an avulsed flap is a good method for addressing aesthetic concerns without producing donor site morbidity. Fluorescein dye is a useful, simple, and cost-effective tool for evaluating flap viability. Avulsed flap injuries can be managed well with Wood's lamp illumination and a full-thickness skin graft. PMID:24665420

  12. The UK National Flap Registry (UKNFR): A National Database for all pedicled and free flaps in the UK.

    PubMed

    Hazari, Anita; Walton, Peter

    2015-12-01

    The UK National Flap Registry (UKNFR) is a cross-speciality National Clinical Audit with participation by the British Association of Plastic Reconstructive and Aesthetic Surgeons (BAPRAS), British Association of Head and Neck Oncologists (BAHNO), British Association of Oral and Maxillofacial Surgeons (BAOMS) and Association of Breast Surgery (ABS). The aim of UKNFR is to collect information about all major pedicled and free flap operations carried out in the UK and through that, assess the quality of care we provide for patients. This audit will allow appropriate comparison of clinical performance with national standards and provide useful data on changing trends. Participation in audit is integral to appraisal and revalidation in the UK.

  13. Reconstruction of large head and neck deformities: experience with free gracilis muscle and myocutaneous flaps.

    PubMed

    Del Frari, Barbara; Schoeller, Thomas; Wechselberger, Gottfried

    2010-01-01

    Microvascular free flaps continue to revolutionize coverage options in head and neck reconstruction. The authors describe their experience with the gracilis free flap and the myocutaneous gracilis free flap with reconstruction of head and neck defects. Eleven patients underwent 12 free tissue transfer to the head and neck region. The reconstruction was performed with the transverse myocutaneous gracilis (TMG) flap (n = 7) and the gracilis muscle flap with skin graft (n = 5). The average patient age was 63.4 years (range, 17-82 years). The indications for this procedure were tumor and haemangioma resections. The average patient follow-up was 20.7 months (range, 1 month-5.7 years). Total flap survival was 100%. There were no partial flap losses. Primary wound healing occurred in all cases. Recipient site morbidities included one hematoma. In our experience for reconstruction of moderate volume and surface area defects, muscle flaps with skin graft provide a better color match and skin texture relative to myocutaneous or fasciocutaneous flaps. The gracilis muscle free flap is not widely used for head and neck reconstruction but has the potential to give good results. As a filling substance for large cavities, the transverse myocutaneus gracilis flap has many advantages including reliable vascular anatomy, relatively great plasticity and a concealed donor area.

  14. Non-invasive terahertz imaging of tissue water content for flap viability assessment

    PubMed Central

    Bajwa, Neha; Au, Joshua; Jarrahy, Reza; Sung, Shijun; Fishbein, Michael C.; Riopelle, David; Ennis, Daniel B.; Aghaloo, Tara; St. John, Maie A.; Grundfest, Warren S.; Taylor, Zachary D.

    2016-01-01

    Accurate and early prediction of tissue viability is the most significant determinant of tissue flap survival in reconstructive surgery. Perturbation in tissue water content (TWC) is a generic component of the tissue response to such surgeries, and, therefore, may be an important diagnostic target for assessing the extent of flap viability in vivo. We have previously shown that reflective terahertz (THz) imaging, a non-ionizing technique, can generate spatially resolved maps of TWC in superficial soft tissues, such as cornea and wounds, on the order of minutes. Herein, we report the first in vivo pilot study to investigate the utility of reflective THz TWC imaging for early assessment of skin flap viability. We obtained longitudinal visible and reflective THz imagery comparing 3 bipedicled flaps (i.e. survival model) and 3 fully excised flaps (i.e. failure model) in the dorsal skin of rats over a postoperative period of 7 days. While visual differences between both models manifested 48 hr after surgery, statistically significant (p < 0.05, independent t-test) local differences in TWC contrast were evident in THz flap image sets as early as 24 hr. Excised flaps, histologically confirmed as necrotic, demonstrated a significant, yet localized, reduction in TWC in the flap region compared to non-traumatized skin. In contrast, bipedicled flaps, histologically verified as viable, displayed mostly uniform, unperturbed TWC across the flap tissue. These results indicate the practical potential of THz TWC sensing to accurately predict flap failure 24 hours earlier than clinical examination. PMID:28101431

  15. Island Posterior Thigh Flap Revisited in Covering Extensive Sacral Wounds: Our Experience with Two Patients

    PubMed Central

    2017-01-01

    Deep sacral wounds are best covered by flaps. Posterior thigh flaps have routinely been used to cover such wounds. The flap can however be modified as an island flap. Two patients with extensive sacral wounds were managed with island posterior thigh flaps. Both patients were admitted secondary to road traffic accident with subsequent soft tissue loss of the sacral area. The sacral defects in both patients were approximately 17 cm by 23 cm in dimensions. Unilateral island posterior thigh flap was raised and used to cover the wounds. Postoperatively both patients did well; the donor site and recipient sites healed without any complications. Island posterior thigh flap is thus an option in covering extensive defects of the sacral area. The flap is reliable and easy to raise and has minimal donor site morbidity. By raising it as an island flap the dog ear defect is avoided and the flap is able to be tunneled under the gluteal muscle. This maneuver enables the flap to be advanced further allowing it to cover more distal and extensive defects. PMID:28321356

  16. Sandwich Fascial Anterolateral Thigh Flap in Head and Neck Reconstruction: Evolution or Revolution?

    PubMed Central

    Berli, Jens; Turri-Zanoni, Mario; Battaglia, Paolo; Maggiulli, Francesca; Corno, Martina; Tamborini, Federico; Montrasio, Edoardo; Castelnuovo, Paolo; Valdatta, Luigi

    2017-01-01

    Introduction: The anterolateral thigh perforator flap (ALT) represents the workhorse for most reconstructive efforts in the head and neck regions. The main advantages of this flap are its versatility, the length of the pedicle, and the low morbidity of the donor site. The major drawback is the bulkiness of this flap with the frequent need for secondary revisions. To overcome this, we have developed a novel way to harvest and inset the ALT, called the sandwich fascial ALT flap (SALT). Methods: All patients undergoing head and neck reconstruction using the SALT flap from January 2013 to March 2016 were included in this retrospective analysis. The SALT flap was harvested as a composite flap including the superficial fascia, the subscarpal fat, and the deep fascia. At the recipient site, the flap was inset with the deep fascia facing out. A split thickness skin graft (± dermal substitute) was used to cover the deep fascia and the pedicle. Results: Eleven patients were included: 8 cases of orbital exenteration, 1 case of forehead reconstruction, and 2 cases of palatal reconstruction after radical maxillectomy. Flap survival was 100%. One patient required an early take back for venous thrombosis. The reconstruction was effective in all cases, allowing a prosthetic rehabilitation when required. Donor-site morbidity was minimal. Conclusions: The reconstruction of head and neck defects with a bulky fasciocutaneous ALT flap might not be the best option in every case. The SALT flap could represent a valid alternative for selected cases, with encouraging functional and cosmetic outcomes. PMID:28203499

  17. Effect of intraoperative platelet-rich plasma and fibrin glue application on skin flap survival.

    PubMed

    Findikcioglu, Fulya; Findikcioglu, Kemal; Yavuzer, Reha; Lortlar, Nese; Atabay, Kenan

    2012-09-01

    The experiment was designed to compare the effect of intraoperative platelet-rich plasma (PRP) and fibrin glue application on skin flap survival. In this study, bilateral epigastric flaps were elevated in 24 rats. The right-side flaps were used as the control of the left-side flaps. Platelet-rich plasma, fibrin glue, and thrombin had been applied under the flap sites in groups 1, 2, and 3, respectively. Five days later, all flap pedicles were ligated. Necrotic area measurements, microangiography, and histologic and immunohistochemical evaluations were performed to compare the groups. Platelet-rich plasma reduced necrotic area percentages as compared with other groups. Histologically and microangiographically increased number of arterioles were observed in PRP groups. Thrombin when used alone increased flap necrosis. Vascular endothelial growth factor, platelet-derived growth factor, and transforming growth factor β3 primary antibody staining showed increased neovascularization and reepithelialization in all PRP-applied flaps. This study demonstrated that PRP, when applied intraoperatively under the skin flap, may enhance flap survival. Thrombin used alone was found to be unsuitable in flap surgery.

  18. Calculated effect of various types of flap on take-off over obstacles

    NASA Technical Reports Server (NTRS)

    Wetmore, J W

    1936-01-01

    In order to determine whether or not flaps could be expected to have any beneficial effect on take-off performance, the distances required to take off and climb to an altitude of 50 feet were calculated for hypothetical airplanes, corresponding to relatively high-speed types and equipped with several types of flap. The types considered are the Fowler wing, the Hall wing, the split flap, the balanced split flap, the plain flap, and the external-airfoil flap. The results indicate that substantial reductions in take-off distance are possible through the use of flaps, provided that the proper flap angle corresponding to a given set of conditions is used. The best flap angle for taking off varies inversely as power loading and, to a much smaller extent, varies inversely with wing loading. Apparently, the best take-off characteristics are provided by the type of device in which the flap forms an extension to the main wing as in the case of the Fowler wing and the external-airfoil flap.

  19. 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.

  20. The role of fabricated chimeric free flaps in reconstruction of devastating hand and forearm injuries.

    PubMed

    Giessler, Goetz A; Schmidt, Andreas B; Germann, Guenter; Pelzer, Michael

    2011-11-01

    Devastating hand and forearm injuries almost exclusively need free flap transfer if reconstruction is attempted. Early active and passive motion is only possible with aggressive, early, and comprehensive reconstruction. Despite recent advances in compound flaps, in selected cases it might be wise to harvest several smaller flaps and microsurgically combine them to one "chain-linked" flap "system." Four microsurgically fabricated chimeric free flaps were used in four patients for complex hand and forearm injuries. The combinations were sensate anterolateral thigh (ALT) flap plus sensate extended lateral arm flap (2x), ALT plus free fibula, and ALT plus functional musculocutaneous gracilis muscle. All flaps survived completely. Functional rehabilitation was possible immediately after flap transfer. There were no donor-site complications except two widened scars. The microsurgical fabrication of chimeric free flaps, as well established in head and neck reconstruction, can be successfully adapted to massive hand injuries as well. Individual placement of selected tissue components, early comprehensive reconstruction, and reduction of the number of operations are beneficial in cases that need more than one free flap.

  1. Reconstruction of lower extremity with perforator free flaps by free style approach in pediatric patients.

    PubMed

    Song, Jin Woo; Ben-Nakhi, Muneera; Hong, Joon Pio

    2012-11-01

    Pediatric reconstruction using microsurgery is accepted normal practice, and the use of perforator flaps is slowly increasing. This study presents clinical work using various perforator free flaps by free style approach to reconstruct lower extremity soft tissue defects in pediatric patients and evaluates its efficacy. Between June 2002 and February 2011, 32 cases (mean age: 10.1 years) were reconstructed with free style perforator free flaps. Retrospective evaluations for flap survival, growth character, and other associated morbidities were performed. Flaps used in this series are anterolateral thigh (ALT) perforator, superficial circumflex iliac artery perforator (SCIP), upper medial thigh perforator, and posterior interosseous perforator free flaps. The free style approach for pedicle dissection was successful in all cases. Early postoperative complications were 15.6% from hematoma collection to partial loss of flap. Although there was no total loss in this series, one case needed additional flap coverage to cover the partial loss of the flap. The long-term follow-up showed contracture along the margin, with 16% needing a releasing procedure. Bone growth was not affected by flap contracture. The overall results show perforator flaps using the free style approach to be a reliable and feasible approach for lower extremity reconstruction in the pediatric population.

  2. Effects of Tissue Component Volumes on Vascular Resistance in Free Flaps.

    PubMed

    Ono, Masashi; Takanari, Keisuke; Toriyama, Kazuhiro; Yagi, Shunjiro; Ebisawa, Katsumi; Sawamura, Hisashi; Kambe, Miki; Murotani, Kenta; Kamei, Yuzuru

    2017-01-01

    Background A successful free flap transfer is achieved, in part, by having a thorough understanding of vascular anatomy and blood flow dynamics. We previously reported that vascular resistance differs by type of free flap. To test the hypothesis that the difference reflects the proportion of tissue components within free flaps, we calculated blood flow and vascular resistance for free flaps in which we determined the volume of each tissue component. Methods Measurements and calculations were made for 40 free flap transfers performed at our hospital: 7 radial forearm flaps, 14 anterolateral thigh flaps, and 19 rectus abdominis myocutaneous flaps. Results The vascular resistance of free flaps was inversely related to the volume of each tissue component. Univariate regression analysis revealed that muscle volume correlated most closely with resistance (r = 0.881), followed by skin (r = 0.622), and fat (r = 0.577). Multiple regression analysis confirmed the relationship between combined muscle and fat volume and resistance (R(2) = 0.865). Conclusions A strong inverse correlation exists between vascular resistance and combined muscle and fat tissue volume in flaps. It may be helpful to consider these relationships when making decisions regarding choice of free flap and recipient vessels.

  3. A brief history of vascularized free flaps in the oral and maxillofacial region.

    PubMed

    Steel, Ben J; Cope, Martin R

    2015-04-01

    Vascularized free flaps are now the reference standard for the reconstruction of defects after cancer resection in oral and maxillofacial surgery and other specialties and have an interesting and surprisingly long history. We reviewed the history of free flap use in oral and maxillofacial surgery and show their place in the wider context of surgical progress. An overview is given of both soft tissue and bony reconstruction in the pre-free flap era and the development of vascular anastomosis and microsurgery--one of the main foundations of free flap surgery. The emergence of free flaps from 1959 through to the early 1970s is documented. The history of 19 of the more common free flaps used in oral and maxillofacial surgery is described, from the jejunal flap in 1959 through to the posterior tibial artery flap in 1985. For each, the origin and first reported use in the head and neck are discussed. Free flap surgery has continued to evolve, with developments in perforator and chimeric flaps, and new flaps continue to be described. An appreciation of the surgical history is important in understanding where we are today. Our review should give the practicing surgeon an idea of the origins of the currently used techniques.

  4. The perforator-based conjoint (chimeric) medial Sural(MEDIAL GASTROCNEMIUS) free flap.

    PubMed

    Sano, Kazufumi; Hallock, Geoffrey G; Hamazaki, Masahiro; Daicyo, Yoshihiro

    2004-12-01

    The prototypical conjoint or so-called "chimeric" free flap heretofore has been composed of several large independent flaps, each supplied by a separate major branch, that ultimately arise from a common source vessel. The perforator-based type of chimeric flap is a relatively new concept, usually involving multiple muscle perforator flaps each based on a solitary musculocutaneous perforator, but still arising from the same "mother" vessel. This principle of split cutaneous perforator flaps has been now successfully adapted to the medial suralMEDIAL GASTROCNEMIUS perforator free flap on 2 separate occasions. As a chimeric flap, there was greater flexibility in insetting, and overall flap width may be larger but still narrow enough to allow primary donor site closure; and yet, by definition, only a single recipient site was needed for any microanastomoses. This is further proof that the perforator-based chimeric free flap may be an option for any muscle perforator flap donor site, so that potential donor territories for conjoint flaps have become virtually unlimited.

  5. Water tunnel results of leading-edge vortex flap tests on a delta wing vehicle

    NASA Technical Reports Server (NTRS)

    Delfrate, J. H.

    1986-01-01

    A water tunnel flow visualization test on leading edge vortex flaps was conducted at the flow visualization facility of the NASA Ames Research Center's Dryden Flight Research Facility. The purpose of the test was to visually examine the vortex structures caused by various leading edge vortex flaps on the delta wing of an F-106 model. The vortex flaps tested were designed analytically and empirically at the NASA Langley Research Center. The three flap designs were designated as full-span gothic flap, full-span untapered flap, and part-span flap. The test was conducted at a Reynolds number of 76,000/m (25,000/ft). This low Reynolds number was used because of the 0.076-m/s (0.25-ft/s) test section flow speed necessary for high quality flow visualization. However, this low Reynolds number may have influenced the results. Of the three vortex flaps tested, the part-span flap produced what appeared to be the strongest vortex structure over the flap area. The full-span gothic flap provided the next best performance.

  6. Natural Hirudin Increases Rat Flap Viability by Anti-Inflammation via PARs/p38/NF-κB Pathway

    PubMed Central

    Peng, Liu; Pan, Xinyuan; Yin, Guoqian

    2015-01-01

    The present study aimed to evaluate the effect of natural hirudin on rat random skin flap viability and to determine the mechanism. Forty-eight rats were randomly divided into 2 groups. After the dorsal skin flap operation (3 cm × 10 cm in size), subcutaneous injections of 6 ATU hirudin were administered to group H (n = 24) every 12 h, while group C (n = 24) received an equal volume of 0.9% normal saline. Six rats from each group were euthanized 1, 2, 4, and 7 days after the operation. A full skin sample was collected from these rats to measure the p38-mitogen-activated protein kinase (p38-MAPK), phospho-p38- (Pp38-) MAPK, nuclear factor-κB (NF-κB) p65, phosphor-NF-κB (pNF-κB) p65, tumour necrosis factor- (TNF-) α, interleukin- (IL-) 6, and intercellular adhesion molecule- (ICAM-) 1 levels via western blot (WB) assays. The results showed that flap viability was significantly higher in the hirudin-treated group, which showed a reduced inflammatory response compared with the control group. The Pp38/p38, pNF-κB p65/NF-κB p65, TNF-α, IL-6, and ICAM-1 levels in the hirudin-treated group were lower than those in the control group. The results demonstrated that hirudin could improve random skin flap viability and suggested that this effect maybe occurs by blocking the thrombin/proteinase-activated receptors (PARs)/p38/NF-κB signalling pathway, thus decreasing the inflammatory response. PMID:26770977

  7. 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.

  8. Free Flap Elevation Times in Head and Neck Reconstruction Using the Harmonic Scalpel Shears

    PubMed Central

    DeSerres, Joshua J.; Barber, Brittany R.; Seikaly, Hadi; Harris, Jeffrey R.

    2016-01-01

    Summary: Free tissue transfer has become the mainstay of head and neck cancer (HNC) reconstructive surgery. The objective of the study is to examine the efficacy of the Harmonic Scalpel (HS) Shears on free flap elevation time and complication rates after HNC reconstruction compared with traditional electrocautery. A retrospective review of 215 HNC patients undergoing surgical ablation and free flap reconstruction from January 2010 to April 2013 at the University of Alberta Hospital was undertaken. All patients requiring free flap reconstruction with radial forearm free flap or fibula free flap were included. Overall, there was no significant difference demonstrated between the HS and electrocautery groups for free flap elevation time for RFFFs (P = 0.563) or FFFs (P = 0.087). No differences were observed in donor-site complications. The HS is a reliable, safe, and alternative method of free flap elevation in HNC reconstructive surgery. PMID:27579242

  9. Laparoscopic Free Omental Flap for Craniofacial Reconstruction: A Video Article Demonstrating Operative Technique and Surgical Applications.

    PubMed

    McIntyre, Benjamin C; Lobb, David; Navarro, Fernando; Nottingham, James

    2017-03-01

    The omental flap is a well described pedicled flap for surgical reconstruction of multiple body locations. As a laparoscopically harvested free flap, the omentum offers a minimally invasive solution to many reconstructive problems including extremity and head and neck wounds. This video article highlights the operative technique involved in flap harvest and inset for a cranial defect. An illustrative case involving a 23-year-old female's traumatic scalp degloving injury that was resurfaced by free omental flap and split-thickness skin graft is presented. This patient had stable long-term wound coverage for a very severe injury. Through video media we demonstrate that the laparoscopically harvested free omental flap is a minimally invasive, 2-team operation that provides soft tissue coverage of severe, remote wounds. This video demonstrates a safe operative technique and nuances specific to laparoscopic harvest of this flap.

  10. Double free-flap for a bimalleolar defect of lower leg and ankle.

    PubMed

    Shetty, Naren; Mashalkar, Narendra S; Ellur, Sunder Raj; Kagodu, Karishma

    2016-01-01

    Double free-flaps are necessary when tissue cover cannot be sufficed with a single flap. The other factors to be considered when using two free flaps for resurfacing of distal limb defects are the availability of more than one recipient vessel, the risk of distal limb ischaemia and the donor site morbidity of double flap harvest. If these factors are adequately addressed, double free-flaps can be safely executed for resurfacing distal limb defects with minimal morbidity. We report the simultaneous harvest and transfer of the anterolateral and anteromedial thigh flaps inset and vascularised as double free-flaps to resurface a large bimalleolar defect in a 14-year-old boy with no additional morbidity as compared to that of a single free tissue transfer.

  11. Coverage of defects over toes with distally based local flaps: A report of four cases.

    PubMed

    Koul, Ashok Raj; Patil, Rahul K; Philip, Vinoth Kumar

    2008-01-01

    Reconstruction of the distal foot, especially of the toe has always been a challenging problem. Various methods have been tried with variable success rates and limitations. Presented here is a series of four cases, where distally based flaps were used. Two of them were Extensor Digitorum Brevis (EDB) muscle flaps and the other two were first dorsal metatarsal artery (FDMA) based skin flaps. One in each of the two was augmented with a plantar V-Y advancement flap. All flaps survived completely without any flap- or donor site-related complications. The patients were ambulated two weeks following the reconstruction and were symptom-free after an average follow-up of thirteen months. Distal flaps based on the dorsalis pedis system provide a reliable cover for distal foot defects.

  12. Recurrent squamous cell carcinoma of the scalp treated with serial free flaps: A case report.

    PubMed

    Ikander, Peder; Sørensen, Jens Ahm

    2015-09-01

    Reconstruction of large full thickness scalp defects is always a challenge. Many different techniques can be used, but larger defects often call for a free tissue transfer. The purpose of this report is to present one successful way of treating multiple large scalp defects. A 61-year-old man was seen with recurrent squamous cell carcinoma of the scalp. The lesions were of full thickness, about 10-15 cm in diameter and included the calvarial bone and the dura layer. The reconstruction process included split-thickness skin grafting, local flaps, and three free microvascular flaps; two latissimus dorsi flaps and one anterolateral thigh flap. No total flap loss was seen, but partial flap necrosis called for secondarily reconstruction. The final result was cosmetically acceptable and the patient is of good health. In conclusion, serial free microvascular flaps may be used with good results when dealing with large difficult and recurrent scalp defects.

  13. 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

  14. Split-thickness flap with a semicircular punched-ridge pedicled periosteal flap for implant restoration in highly atrophic patients: a technical note.

    PubMed

    Seemann, Rudolf; Perisanidis, Christos; Traxler, Hannes; Ewers, Rolf

    2014-01-01

    Attached gingiva is a crucial aspect of healthy peri-implant tissue. Severely atrophied jaws have minimal quantities of attached gingiva. Any surgical procedure bears the potential risk of further loss of attached gingiva. The split-thickness flap described here provides excellent access. Using a biopsy punch, the periosteum is easily cut in semicircular fashion on the labial surface of the bone so that it remains pedicled on the lingual or palatal ridge. The split-thickness flap permits fixation of the gingival flap to the periosteum. The periosteal flap is closed with sutures to achieve soft tissue closure over the implants even in case of simultaneous vestibuloplasty.

  15. Protein

    MedlinePlus

    ... Search for: Harvard T.H. Chan School of Public Health Email People Departments Calendar Careers Give my.harvard ... Nutrition Source Harvard T.H. Chan School of Public Health > The Nutrition Source > What Should I Eat? > Protein ...

  16. Protein

    MedlinePlus

    ... Go lean with protein. • Choose lean meats and poultry. Lean beef cuts include round steaks (top loin, ... main dishes. • Use nuts to replace meat or poultry, not in addition to meat or poultry (i. ...

  17. Autonomization of free flaps in the oral cavity: A prospective clinical study.

    PubMed

    Mücke, Thomas; Wolff, Klaus-D; Rau, Andrea; Kehl, Victoria; Mitchell, David A; Steiner, Timm

    2012-03-01

    Controversy exists over how long a free flap is dependent on its pedicle and if neovascularization is different between flap types, recipient sites, and irradiated and nonirradiated patients. An understanding of the timing of this process should optimize the safety of secondary procedures involving the flap. In a prospective clinical study, hemoglobin oxygenation and capillary flow were measured in 50 flaps (25 forearm flaps, 15 osteocutaneous fibula flaps, and 10 anterolateral thigh flaps) 4 and 12 weeks postoperatively. The flaps were located at the floor of the mouth, cheek, or tongue (n = 39) or at the hard or soft palate (n = 11). Measurements were carried out using the O2C monitoring system under temporary digital occlusion of the pedicle. After 4 weeks, 17 free flaps were found to be autonomized indicated by the O2C measurements comparing both values before and after digital compression of the vascular pedicle. After 12 weeks, 41 patients had completion of free flap autonomization, as indicated by the HbO(2) and CF before and after pedicle compression. The location of free flap in the lower jaw (P < 0.0001 after 4 weeks, P = 0.013 after 12 weeks), fasciocutaneous radial forearm flaps after 4 weeks (P < 0.0001), and not irradiated recipient site after 4 weeks (P = 0.014) were found to be positive factors significantly influencing autonomization. In conclusion, free flap autonomization depends on several variables which should be considered before further surgery after free flap reconstruction as the transferred tissue can be still dependent on its pedicle.

  18. Donor-site Morbidity of Medial and Lateral Thigh-based Flaps: A Comparative Study

    PubMed Central

    Purnell, Chad A.; Lewis, Kevin C.; Mioton, Lauren M.; Hanwright, Philip J.; Galiano, Robert D.; Dumanian, Gregory A.; Alghoul, Mohammed S.

    2016-01-01

    Background: Free and pedicled medial and lateral thigh-based flaps are common reconstructive procedures. However, there have been no comparative studies of morbidity between medial and lateral donor sites. Methods: We conducted an Enterprise Data Warehouse-based review of all the senior authors’ (R.D.G., G.A.D., and M.S.A.) thigh-based free and pedicled flaps. Patient demographic data, donor-site complications, drain duration, and number of postoperative visits were collected and compared. Complications were also compared between fasciocutaneous flaps and muscle or myocutaneous flaps, and skin grafted donor sites. Results: We analyzed 352 flap donor sites, with 155 medial and 197 lateral. Two hundred seventeen (217) flaps were pedicled. Flap types included 127 gracilis, 27 rectus femoris, 134 anterolateral thigh, and 36 vastus lateralis-only flaps. There were no significant differences in complications between medial (17.4%) and lateral thigh (21.3%) donor sites, although lateral thigh flaps had a mean of 1 additional postoperative visit. Rates of wound dehiscence/healing issues were significantly higher in both gracilis myocutaneous flaps (25.9%) and flaps requiring a skin grafted donor site (31.2%). Postoperative therapeutic anticoagulation was the only significant risk factor for a donor-site complication. Flap complications resulted in increased drain duration and postoperative office visits. Conclusions: Donor-site morbidity is similar in both lateral and medial thigh-based flaps. The inclusion of muscle in the flap from either donor site does not seem to increase complications, but the inclusion of a skin paddle with gracilis muscle, or a skin grafted lateral thigh donor site, results in increased wound healing complications. PMID:27975004

  19. Use of liposuction for secondary revision of irradiated and nonirradiated free flaps.

    PubMed

    Bui, Duc T; Mehrara, Babak J; Disa, Joseph J; Cordeiro, Peter G

    2004-06-01

    A number of patients with free tissue transfer require secondary revision to improve contour and regional definition to maximize function or appearance. However, there is controversy with regard to whether irradiated free flaps can be revised safely using liposuction. The purpose of this study was to compare the outcomes of revisionary procedures requiring liposuction in irradiated versus nonirradiated flaps. From December 1992 to July 2001, office and hospital records were reviewed retrospectively to identify patients who had undergone free tissue transfer and subsequent flap revision at a single institution. The number of revisions, amount of fat aspirated, timing of revision and the postoperative complications including infection, hematoma, wound dehiscence, and flap loss were reviewed. A total of 41 flap revisions using liposuction alone or with direct excision were performed on 33 free flaps (31 head and neck, 1 chest wall, and 1 extremity). The rectus musculocutaneous flap was the most commonly revised (88%). The average length of time to secondary revision of patients who had received postoperative radiotherapy to their flaps was significantly higher that those whose flaps had not been irradiated (P < 0.05). There were no postoperative complications except for 1 partial (20%) flap loss in a patient whose flap was irradiated. The difference in complication rates between the irradiated and nonirradiated group was not statistically significant. Secondary free flap revision using liposuction and direct excision is a safe technique for recontouring free flaps. There was no significant difference in complication rates for irradiated and nonirradiated flaps. Postoperative radiation therapy is therefore not a contraindication to secondary revision. However, these procedures should be delayed for several months after the acute effects of radiation have resolved.

  20. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... sides of the plane of symmetry must be synchronized by a mechanical interconnection or approved... engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. (c... resulting when interconnected flap or slat surfaces on one side of the plane of symmetry are jammed...

  1. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... sides of the plane of symmetry must be synchronized by a mechanical interconnection or approved... engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. (c... resulting when interconnected flap or slat surfaces on one side of the plane of symmetry are jammed...

  2. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... sides of the plane of symmetry must be synchronized by a mechanical interconnection or approved... engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. (c... resulting when interconnected flap or slat surfaces on one side of the plane of symmetry are jammed...

  3. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... sides of the plane of symmetry must be synchronized by a mechanical interconnection or approved... engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. (c... resulting when interconnected flap or slat surfaces on one side of the plane of symmetry are jammed...

  4. 14 CFR 25.701 - Flap and slat interconnection.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... sides of the plane of symmetry must be synchronized by a mechanical interconnection or approved... engines on one side of the plane of symmetry inoperative and the remaining engines at takeoff power. (c... resulting when interconnected flap or slat surfaces on one side of the plane of symmetry are jammed...

  5. Combined latissimus dorsi and serratus anterior flaps for pelvic reconstruction.

    PubMed

    Phan, Truong Q V; Spilker, Gerald; Theodorou, Panagiotis; Gossmann, Andreas; Heiss, Michael; Weinand, Christian

    2011-10-01

    In recurrent pressure sores, adjacent tissue has already been consumed by multiple surgeries. Additional problems are several co-morbidities of patients. Especially, severe atherosclerosis would be a contraindication for using free flaps. However, microsurgical techniques allow circumventing these limitations and preparing even severely atherosclerotic vessels. We performed a total of eight sacral pressure sore coverage in our standardized fashion, using the free combined latissimus dorsi and serratus anterior free flaps. All patients had severe atherosclerosis and needed large soft tissue coverage of the sacral defects. Five patients presented after bowel resection, three with recurrent sacral pressure sores. The average follow-up was 12 months. Postoperatively, all patients were allowed to be prone on the operated area. One minor wound dehiscence was sutured in local anesthesia. CT imaging analysis of the pelvis showed complete void space coverage. The combined latissimus dorsi and serratus anterior flaps are a valuable tool for pelvic reconstruction in our hands. In addition, severe atherosclerosis should not be considered an obstacle to microsurgery and the use of free flaps.

  6. Detail view of the underside of the Body Flap of ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    Detail view of the underside of the Body Flap of the Orbiter Discovery as it is being rotated into a vertical position in the Vehicle Assembly Building at Kennedy Space Center. - Space Transportation System, Orbiter Discovery (OV-103), Lyndon B. Johnson Space Center, 2101 NASA Parkway, Houston, Harris County, TX

  7. Vortex flap flight test operations, a safe approach

    NASA Technical Reports Server (NTRS)

    Dicarlo, Daniel J.; Elliott, James R.

    1993-01-01

    A flight test experiment was conducted at the Langley Research Center to evaluate a wing leading-edge vortex flap concept designed for use on an aircraft with highly swept wings. The flap concept was designed as a modification to the wing leading edge of an F-106B airplane. The flight testing required operations at conditions that would exceed the structural load envelope of the basic airplane in order to acquire desired research data for the modified configuration. Accordingly, the operational envelope of the modified aircraft was incrementally expanded and real-time monitoring of airframe strains at critical wing locations was mandated to insure safety of flight. The flight tests were conducted in two phases: Phase I to establish baseline data with the unmodified wing, and Phase II to determine the effects of the vortex flap on performance, handling qualities, and flow field characteristics. This paper focuses on a description of the approach and procedures used to provide the strain-gage monitoring to insure structural integrity. Highlights of the wing modification and the overall operation are also included. Within a -year period, 110 research flights were successfully completed, providing researchers with sufficient data to assess the potential benefits ascribed to the vortex flap concept without encountering severe structural problems or mishaps.

  8. Usefulness of Harmonic Focus during anterolateral thigh flap elevation.

    PubMed

    Hamahata, Atsumori; Saitou, Takashi; Kubo, Kazuyuki; Beppu, Takeshi; Yamaki, Takashi; Sakurai, Hiroyuki

    2012-11-01

    Meticulous hemostasis and careful ligation of branches are necessary for pedicle dissection during flap elevation. The aim of this study was to evaluate the effectiveness of the Harmonic Focus handpiece (Ethicon Endo-Surgery, Inc., Blue Ash, Cincinnati, OH, USA) in reducing operation time, bleeding volume, and volume of postoperative drainage during anterolateral thigh flap elevation. Ten patients requiring flap elevation were divided into two groups: (1) Harmonic Focus group (three men, two women), and (2) control group (three men, two women). Operating time was found to be lower in the Harmonic Focus group than in the control group. Bleeding volume and postoperative drainage volume were nearly identical in the Harmonic Focus group and the control group, and the number of silk ligatures was significantly lower in the Harmonic Focus group compared with the control group. Although somewhat costly, the Harmonic Scalpel with the Harmonic Focus handpiece is advantageous for flap elevation, and it is likely that Harmonic Scalpel use will increase in plastic surgery.

  9. 6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    6. CLOSEUP VIEW OF THE PUMP DISCHARGE CHANNEL, THE FLAP VALVES OF THE PUMPING UNITS 8, 6, AND 7 (L TO R) AND PART OF THE DISCHARGE WEIR OF THE INDIVIDUAL DISCHARGE CHAMBER OF PUMP NO. 5, LOOKING NORTHEAST. - Wyoming Valley Flood Control System, Woodward Pumping Station, East of Toby Creek crossing by Erie-Lackawanna Railroad, Edwardsville, Luzerne County, PA

  10. [Oromandibular reconstruction with free peroneal flap and osseointegrated implants].

    PubMed

    Navarro Cuéllar, C; Cuesta Gil, M; Plasencia Delgado, J; Guerra Martínez, B; Acero Sanz, J; López de Atalaya, F J; Ochandiano Caicoya, S; Navarro Vila, C

    2003-01-01

    Free fibula flaps have proved to be one of the most versatile for oromandibular reconstruction due to the available length of bone and the possibility of incorporating a long skin paddle to cover intraoral soft tissues. The use of a osseointegrated dental implants is an important technique for the oral rehabilitation of these patients. Osseointegrated implants provide the most rigid prosthetic stabilization available to withstand masticatory forces. These implants can be placed immediately or in second time procedure. In our case, implantation in the fibula free flap is done after 6-9 months because of the large amount of osteosynthesis material required for the fixation of the flap. Four or six months later, when osseointegration has taken place, the implants are loaded with a dental rehabilitation. We analize 10 cases of mandibular reconstruction with fibula free flap and their aesthetic and functional rehabilitation with osseointegrated implants with a 2 year follow up. Forty-six dental implants were placed developing all of them but one a correct osseointegration. All these patients recovered masticatory function and underwent a considerable improvement in labial competence, salivary continence, speech articulation and facial harmony.

  11. Aeroacoustic Evaluation of Flap and Landing Gear Noise Reduction Concepts

    NASA Technical Reports Server (NTRS)

    Khorrami, Mehdi R.; Humphreys, William M., Jr.; Lockard, David P.; Ravetta, Patricio A.

    2014-01-01

    Aeroacoustic measurements for a semi-span, 18% scale, high-fidelity Gulfstream aircraft model are presented. The model was used as a test bed to conduct detailed studies of flap and main landing gear noise sources and to determine the effectiveness of numerous noise mitigation concepts. Using a traversing microphone array in the flyover direction, an extensive set of acoustic data was obtained in the NASA Langley Research Center 14- by 22-Foot Subsonic Tunnel with the facility in the acoustically treated open-wall (jet) mode. Most of the information was acquired with the model in a landing configuration with the flap deflected 39 deg and the main landing gear alternately installed and removed. Data were obtained at Mach numbers of 0.16, 0.20, and 0.24 over directivity angles between 56 deg and 116 deg, with 90 deg representing the overhead direction. Measured acoustic spectra showed that several of the tested flap noise reduction concepts decrease the sound pressure levels by 2 - 4 dB over the entire frequency range at all directivity angles. Slightly lower levels of noise reduction from the main landing gear were obtained through the simultaneous application of various gear devices. Measured aerodynamic forces indicated that the tested gear/flap noise abatement technologies have a negligible impact on the aerodynamic performance of the aircraft model.

  12. Inverted Internal Limiting Membrane Flap For Large Traumatic Macular Holes

    PubMed Central

    Abou Shousha, Mohsen Ahmed

    2016-01-01

    Abstract The aim of the study was to assess the role of inverted internal limiting membrane flap as a treatment option for large traumatic macular holes. This is a prospective noncomparative study in which 12 eyes with large traumatic macular holes (basal diameter of 1300–2800 μm) since 3 to 6 months were subjected to standard 23-gauge vitrectomy with removal of the posterior hyaloid, brilliant blue G (BBG)-assisted internal limiting membrane peeling in a circular fashion keeping it attached to the edge of the hole to create a flap. At the end of the surgery, air fluid exchange was done with inversion of the internal limiting membrane flap inside the macular hole using the soft tipped cannula and sulfur hexafluoride 20% as tamponade. The main follow-up measures are the best corrected visual acuity and the optical coherence tomography for 6 to 9 months. All the included eyes had a closed hole from the first week postoperative and along the follow-up period (6–9 months). The best corrected visual acuity improved from 20/2000 to 20/200 with a median of 20/400 preoperatively to 20/400 to 20/50 with a median of 20/100 at the end of follow-up period. Inverted internal limiting membrane flap is a good adjuvant to standard vitrectomy in the management of large traumatic macular holes that led to the 100% closure rate and improvement of best corrected visual acuity. PMID:26817894

  13. The phonetic context of American English flapping: quantitative evidence.

    PubMed

    Eddington, David; Elzinga, Dirk

    2008-01-01

    The phonetic context in which word-medial flaps occur (in contrast to [th]) in American English is explored. The analysis focuses on stress placement, following phone, and syllabification. In Experiment 1, subjects provided their preference for [th] or [[symbol: see text

  14. Simulation of a flap actuator for turbulence control

    NASA Astrophysics Data System (ADS)

    Mansfield, John; Kim, John

    1998-11-01

    Neural net control algorithms have been developed by our group which use spanwise shear stress at the wall as the sensory input and blowing and suction at the wall as the actuation to be controlled. These controls result in a 20% drag reduction in DNS of low Reynolds number turbulent channel flow. We have also used suboptimal control theory and systems control theory in simulations of blowing/suction control. A MEMS device which is simpler to manufacture, install, and precisely control, however, uses instead microflaps as the actuators. DNS of such fine structures would be beyond present computational capabilities. Instead we have developed a procedure using a body force to represent effects of the flaps on the flow. The method takes the surface forces that would be generated to satisfy the no-slip condition at the flap surfaces (which generally do not coincide with the computational mesh) and distributes them as a body force on the nodes of the computational mesh. Simulation results are compared with wind tunnel experimental data for the interaction of a moving flap with streamwise vortices passing over it. DNS of a fully developed turbulent flow controlled by an array of flap actuators, whose motions are activated by a neural network is currently underway. Results from this simulation will be presented.

  15. Tadalafil significantly reduces ischemia reperfusion injury in skin island flaps

    PubMed Central

    Kayiran, Oguz; Cuzdan, Suat S.; Uysal, Afsin; Kocer, Ugur

    2013-01-01

    Introduction: Numerous pharmacological agents have been used to enhance the viability of flaps. Ischemia reperfusion (I/R) injury is an unwanted, sometimes devastating complication in reconstructive microsurgery. Tadalafil, a specific inhibitor of phosphodiesterase type 5 is mainly used for erectile dysfunction, and acts on vascular smooth muscles, platelets and leukocytes. Herein, the protective and therapeutical effect of tadalafil in I/R injury in rat skin flap model is evaluated. Materials and Methods: Sixty epigastric island flaps were used to create I/R model in 60 Wistar rats (non-ischemic group, ischemic group, medication group). Biochemical markers including total nitrite, malondialdehyde (MDA) and myeloperoxidase (MPO) were analysed. Necrosis rates were calculated and histopathologic evaluation was carried out. Results: MDA, MPO and total nitrite values were found elevated in the ischemic group, however there was an evident drop in the medication group. Histological results revealed that early inflammatory findings (oedema, neutrophil infiltration, necrosis rate) were observed lower with tadalafil administration. Moreover, statistical significance (P < 0.05) was recorded. Conclusions: We conclude that tadalafil has beneficial effects on epigastric island flaps against I/R injury. PMID:23960309

  16. The role of passive avian head stabilization in flapping flight

    PubMed Central

    Pete, Ashley E.; Kress, Daniel; Dimitrov, Marina A.; Lentink, David

    2015-01-01

    Birds improve vision by stabilizing head position relative to their surroundings, while their body is forced up and down during flapping flight. Stabilization is facilitated by compensatory motion of the sophisticated avian head–neck system. While relative head motion has been studied in stationary and walking birds, little is known about how birds accomplish head stabilization during flapping flight. To unravel this, we approximate the avian neck with a linear mass–spring–damper system for vertical displacements, analogous to proven head stabilization models for walking humans. We corroborate the model's dimensionless natural frequency and damping ratios from high-speed video recordings of whooper swans (Cygnus cygnus) flying over a lake. The data show that flap-induced body oscillations can be passively attenuated through the neck. We find that the passive model robustly attenuates large body oscillations, even in response to head mass and gust perturbations. Our proof of principle shows that bird-inspired drones with flapping wings could record better images with a swan-inspired passive camera suspension. PMID:26311316

  17. DETAIL OF GASPROOF DOOR SHOWING THE THREE ROUND FLAP VALVES ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    DETAIL OF GAS-PROOF DOOR SHOWING THE THREE ROUND FLAP VALVES AT THE BASE OF THE DOOR - U.S. Naval Base, Pearl Harbor, Ford Island 5-Inch Antiaircraft Battery, Battery Command Center, Ford Island, Pearl City, Honolulu County, HI

  18. The role of passive avian head stabilization in flapping flight.

    PubMed

    Pete, Ashley E; Kress, Daniel; Dimitrov, Marina A; Lentink, David

    2015-09-06

    Birds improve vision by stabilizing head position relative to their surroundings, while their body is forced up and down during flapping flight. Stabilization is facilitated by compensatory motion of the sophisticated avian head-neck system. While relative head motion has been studied in stationary and walking birds, little is known about how birds accomplish head stabilization during flapping flight. To unravel this, we approximate the avian neck with a linear mass-spring-damper system for vertical displacements, analogous to proven head stabilization models for walking humans. We corroborate the model's dimensionless natural frequency and damping ratios from high-speed video recordings of whooper swans (Cygnus cygnus) flying over a lake. The data show that flap-induced body oscillations can be passively attenuated through the neck. We find that the passive model robustly attenuates large body oscillations, even in response to head mass and gust perturbations. Our proof of principle shows that bird-inspired drones with flapping wings could record better images with a swan-inspired passive camera suspension.

  19. Intraoperative esophageal Doppler hemodynamic monitoring in free perforator flap surgery.

    PubMed

    Figus, Andrea; Wade, Ryckie G; Oakey, Stephen; Ramakrishnan, Venkat V

    2013-03-01

    Goal-directed fluid therapy optimizes cardiac output and flap perfusion during anesthesia. Intraoperative esophageal Doppler (ED) monitoring has been reported as more accurate and reliable, demonstrating improved surgical outcomes compared with central venous pressure and arterial catheter monitoring. A prospective study of patients undergoing free perforator (deep inferior epigastric artery perforator/anterolateral thigh) flap surgery with intraoperative ED monitoring (51 patients) or central venous pressure monitoring (53 patients) was undertaken. Fluid input included crystalloids, colloids, or blood products. Fluid output included urine, blood, or suctioned fluid. Postoperative fluid balance was calculated as fluid input - output. Fluid input between groups was not different. Fluid output was greater in the ED group (P = 0.008). The ED group showed less fluid balance (P = 0.023), less anesthetic time (P = 0.001), less hospital stay (mean 1.9 days; P = 0.147), less monitoring and flap complications (P = 0.062). ED monitoring demonstrated no monitoring complications, provides a favorable postoperative fluid balance, and may reduce flap complications and hospital stay.

  20. Inverted Internal Limiting Membrane Flap For Large Traumatic Macular Holes.

    PubMed

    Abou Shousha, Mohsen Ahmed

    2016-01-01

    The aim of the study was to assess the role of inverted internal limiting membrane flap as a treatment option for large traumatic macular holes.This is a prospective noncomparative study in which 12 eyes with large traumatic macular holes (basal diameter of 1300-2800 μm) since 3 to 6 months were subjected to standard 23-gauge vitrectomy with removal of the posterior hyaloid, brilliant blue G (BBG)-assisted internal limiting membrane peeling in a circular fashion keeping it attached to the edge of the hole to create a flap. At the end of the surgery, air fluid exchange was done with inversion of the internal limiting membrane flap inside the macular hole using the soft tipped cannula and sulfur hexafluoride 20% as tamponade. The main follow-up measures are the best corrected visual acuity and the optical coherence tomography for 6 to 9 months.All the included eyes had a closed hole from the first week postoperative and along the follow-up period (6-9 months). The best corrected visual acuity improved from 20/2000 to 20/200 with a median of 20/400 preoperatively to 20/400 to 20/50 with a median of 20/100 at the end of follow-up period.Inverted internal limiting membrane flap is a good adjuvant to standard vitrectomy in the management of large traumatic macular holes that led to the 100% closure rate and improvement of best corrected visual acuity.

  1. Flexible flapping wings with self-organized microwrinkles.

    PubMed

    Tanaka, Hiroto; Okada, Hiroyuki; Shimasue, Yosuke; Liu, Hao

    2015-06-29

    Bio-inspired flapping wings with a wrinkled wing membrane were designed and fabricated. The wings consist of carbon fibre-reinforced plastic frames and a polymer film with microscale wrinkles inspired by bird feathers and the corrugations of insect wings. The flexural and tensile stiffness of the wrinkled film can be controlled by modifying the orientations and waveforms of the wrinkles, thereby expanding the design space of flexible wings for micro flapping-wing aerial robots. A self-organization phenomenon was exploited in the fabrication of the microwrinkles such that microscale wrinkles spanning a broad wing area were spontaneously created. The wavy shape of these self-organized wrinkles was used as a mould, and a Parylene film was deposited onto the mould to form a wrinkled wing film. The effect of the waveforms of the wrinkles on the film stiffness was investigated theoretically, computationally and experimentally. Compared with a flat film, the flexural stiffness was increased by two orders of magnitude, and the tensile stiffness was reduced by two orders of magnitude. To demonstrate the effect of the wrinkles on the actual deformation of the flapping wings and the resulting aerodynamic forces, the fabricated wrinkled wings were tested using a tethered electric flapping mechanism. Chordwise unidirectional wrinkles were found to prevent fluttering near the trailing edge and to produce a greater aerodynamic lift compared with a flat wing or a wing with spanwise wrinkles. Our results suggest that the fine stiffness control of the wing film that can be achieved by tuning the microwrinkles can improve the aerodynamic performance of future flapping-wing aerial robots.

  2. SUBAERF2 - WING AND FLAP SYSTEM ANALYSIS CODE

    NASA Technical Reports Server (NTRS)

    Carlson, H. W.

    1994-01-01

    The SUBAERF2 program was developed to provide for the aerodynamic analysis and design of low speed wing flap systems. SUBAERF2 is based on a linearized theory lifting surface solution. It is particularly well suited to configurations which, because of high speed flight requirements, must employ thin wings with highly swept leading edges. The program is applicable to wings with either sharp or rounded leading edges. This program is a new and improved version of LAR-13116 and LAR-12987, which it replaces. The low speed aerodynamic analysis method used in SUBAERF2 provides estimates of wing performance which include the effects of attainable leading-edge thrust and vortex lift. This basic aerodynamic analysis method has been improved to provide for the convenient, efficient and accurate treatment of simple leading-edge and trailing-edge flap systems. The user inputs flap geometry directly. Solutions can be found for various combinations of leading and trailing edge flap deflections. The program provides for the simultaneous analysis of up to 25 pairs of leading-edge and trailing-edge flap deflection schedules. A revised attainable thrust algorithm improves accuracy at the low Mach numbers sometimes encountered in wind tunnel testing. Also added is a means of estimating the distribution of leading edge separation vortex forces. The revised program has been particularly useful in the subsonic analysis of vehicles designed for supersonic cruise. The SUBAERF2 program is written in FORTRAN V for batch execution and has been implemented on a CDC 175 computer operating under NOS 2.4 with a central memory requirement of approximately 115K (octal) of 60 bit words. This program was originally developed in 1983 and later revised in 1988.

  3. Fibular free flap reconstruction of the "true" lateral mandibular defect.

    PubMed

    Anthony, J P; Foster, R D; Kaplan, M J; Singer, M I; Pogrel, M A

    1997-02-01

    The purpose of this study was to determine the role of the fibular free flap in reconstructing lateral segmental defects of the mandible. Over the past 5 1/2 years, 17 consecutive patients underwent reconstruction of their lateral mandible with the fibular free flap. Patients included 12 men and 5 women, the mean age was 54 years (range, 29-76 years), and the mean length of the mandibular defect was 6.3 cm (range, 2.5-9 cm). The majority of patients with tumors (54%) were treated for recurrence and 92% received radiation to the operative field. The mean operative time to perform the microsurgery and bone plating was 4 hours. Postoperative morbidity occurred in 3 patients (18%) (plate fracture, malocclusion, orocutaneous fistula). Five patients (29%) required leg donor site skin grafting. Donor site morbidity included a minor cellulitis, a transient neuropraxia, and one case of leg swelling. None required additional surgery for donor complications. Thus far, 71% of the patients have received dental rehabilitation and 35% had osseointegrated implants placed in their bone flap. Eighty-two percent of the patients achieved both good or excellent aesthetic and functional results. Sixteen patients (94%) tolerate at least a soft diet and 65% are on a regular diet. Five patients developed tumor recurrence an average of 9 months postoperatively with a mean survival of 21 months. This study demonstrates that the fibular free flap is highly reliable for reconstructing the lateral mandible in a single stage, with low overall morbidity, and provides for excellent dental and speech rehabilitation. For most patients, the fibular free flap should be considered for lateral mandibular reconstruction even in those patients with a limited life expectancy.

  4. Flap Reconstruction for Pressure Ulcers: An Outcomes Analysis

    PubMed Central

    Madden, James J.; Hoffman, Ashley N.; Kim, Justine S.; Thayer, Wesley P.; Nanney, Lillian B.; Spear, Marcia E.

    2017-01-01

    Background: Historically, complication rates after pressure ulcer reconstruction utilizing flap coverage have been high. Patients undergoing operations for pressure ulcer coverage typically have multiple risk factors for postoperative complications. The purpose of this study was to examine a large patient series in the pressure ulcer population to uncover objective evidence of the linkage between risk factors and outcomes after flap coverage. Methods: This study was a retrospective chart review of patients who underwent flap reconstruction for a pressure ulcer between 1997 and 2015. The characteristics of patients were analyzed to determine those who had complications such as pressure ulcer recurrence, wound dehiscence, and wound infection. Results: All patients (N = 276) underwent flap coverage of their pressure ulcers. The overall complication rate was 58.7% (162 patients). Wound dehiscence was the most common complication (31.2%), and the pressure ulcer recurrence rate was 28.6%. Multivariate regression for pressure ulcer recurrence revealed that body mass index <18.5 [relative risk (RR) 3.13], active smoking (RR 2.33), and ischial pressure ulcers (RR 3.46) were independent risk factors for pressure ulcer recurrence. Ischial pressure ulcers (RR 2.27) and preoperative osteomyelitis (RR 2.78) were independent risk factors for wound dehiscence. Diabetes was an independent risk factor for wound infection (RR 4.34). Conclusions: Our retrospective analysis revealed numerous factors that are associated with high rates of major postoperative complications. Risk factors must be taken into account when offering flap coverage, and risk-reducing strategies must be implemented in patients before pressure ulcer reconstruction. PMID:28203494

  5. Wound Dehiscence after Wisdom Tooth Removal in Mandibular Mesioangular Class IB Impactions: Triangular Transposition Flap versus Envelope Flap.

    PubMed

    Rahpeyma, Amin; Khajehahmadi, Saeedeh; Ilkhani, Sina

    2015-01-01

    Background and aims. Wound dehiscence after lower third molar surgery extends the postoperative treatment period and may cause long-standing pain. The aim of this study was to compare wound dehiscence after removal of wisdom teeth in the most prevalent mandibular impaction (mesioangular class IB) by two different soft tissue flap designs. Materials and methods. Partially-erupted mandibular third molars with mesioangular class IB impaction (Pell and Gregory classification) were selected. Split mouth technique was used to compare the two flap designs (envelope vs. triangular transposition flap-TTF). The patients were recalled one week and a month later and rechecked for dehiscence, infection, and dry socket formation. Results. There were no cases of infection in either group. However, three cases of dry socket in the envelope group and four in the TTF group were recorded. In the envelope group, dehiscence occurred in 43% of cases during the first week, with 67% of cases being a large dehiscence (diameters of more than 5 mm). Extra appointments (those requested by the patient exclusively related to the problem of the hole distal to the second molar) were scheduled in 10% of cases in the envelope group. In the TTF group, dehiscence occurred during the first week for the same impaction in 19% of cases with large dehiscence cases occurring in 65% of cases and extra appointment rate at 4.1%. Conclusion. According to theresults in the evaluated operation, TTF may prevent postoperative wound dehiscence more probably than the envelope flap.

  6. Assessing the suitability of medial sural artery perforator flaps in tongue reconstruction – An outcome study

    PubMed Central

    Kwon, Soo-Ha; Tsai, Chia-Hsuan; Chang, Kai-Ping; Kao, Huang-Kai

    2017-01-01

    Introduction Oncological resection of the tongue can be reconstructed using a multitude of free flaps. The medial sural artery perforator (MSAP) flap has been well described in the literature in terms of its anatomy and harvest. However, functional outcome studies of post-reconstruction tongue defects using the MSAP flap have not been reported. This study represents the largest outcome study of patients with tongue reconstructions using MSAP flaps and a comprehensive review of its use. Materials and methods From December of 2010 to October of 2015, 579 patients with subtotal glossectomy and free flap reconstructions in Chang Gung Memorial Hospital were retrospectively reviewed. 27 patients were reconstructed with MSAP flap. The pre- and intra-operative factors, as well as flap-related factors were analyzed. Post-operative complications and functional outcomes were evaluated. Donor site assessment were also conducted. Results A 96.3% flap survival rate was found with an average total operating time of 6 hours and 18 minutes. 84.6% of patients had primary closure of the donor site with and the remaining either had skin grafts or delayed closure. Donor site closure can be achieved primarily with no functional deficit. Speech intelligibility remained for most patients. 100% of patients resumed normal oral feeding. Conclusion The MSAP flap is a small to medium sized flap most suited for subtotal glossectomy defects where optimal outcomes can be achieved in terms of speech clarity and restoration of oral intake. PMID:28182639

  7. Heart rate and estimated energy expenditure of flapping and gliding in black-browed albatrosses.

    PubMed

    Sakamoto, Kentaro Q; Takahashi, Akinori; Iwata, Takashi; Yamamoto, Takashi; Yamamoto, Maki; Trathan, Philip N

    2013-08-15

    Albatrosses are known to expend only a small amount of energy during flight. The low energy cost of albatross flight has been attributed to energy-efficient gliding (soaring) with sporadic flapping, although little is known about how much time and energy albatrosses expend in flapping versus gliding during cruising flight. Here, we examined the heart rates (used as an instantaneous index of energy expenditure) and flapping activities of free-ranging black-browed albatrosses (Thalassarche melanophrys) to estimate the energy cost of flapping as well as time spent in flapping activities. The heart rate of albatrosses during flight (144 beats min(-1)) was similar to that while sitting on the water (150 beats min(-1)). In contrast, heart rate was much higher during takeoff and landing (ca. 200 beats min(-1)). Heart rate during cruising flight was linearly correlated with the number of wing flaps per minute, suggesting an extra energy burden of flapping. Albatrosses spend only 4.6±1.4% of their time flapping during cruising flight, which was significantly lower than during and shortly after takeoff (9.8±3.5%). Flapping activity, which amounted to just 4.6% of the time in flight, accounted for 13.3% of the total energy expenditure during cruising flight. These results support the idea that albatrosses achieve energy-efficient flight by reducing the time spent in flapping activity, which is associated with high energy expenditure.

  8. 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.

  9. Complications and oncologic outcomes of pedicled transverse rectus abdominis myocutaneous flap in breast cancer patients

    PubMed Central

    Somintara, Ongart; Lertsithichai, Panuwat; Kongdan, Youwanush; Supsamutchai, Chairat; Sukpanich, Rupporn

    2016-01-01

    Background There are several techniques for harvesting the pedicled transverse rectus abdominis myocutaneous (TRAM) flap after mastectomy in breast cancer patients. We examined the whole muscle with partial sheath sparing technique and determined factors associated with its complications and oncological outcomes. Methods We retrospectively reviewed the results of 168 TRAM flaps performed between January 2003 and December 2010, focusing on complications and oncologic outcomes. Results Among the 168 pedicled TRAM flap procedures in 158 patients, flap complications occurred in 34%. Most of the flap complications included some degree of fat necrosis. There was no total flap loss. Flap complications were associated with elderly patients and the presence of major donor site complications. Abdominal bulging and hernia occurred in 12% of patients. The bi-pedicled TRAM flap and higher body mass index (BMI) were significant factors associated with increased donor site complications. Seven patients (4%) developed loco-regional recurrence. Within a median follow-up of 27 months, distant metastasis and death occurred in 6% and 4% of patients, respectively. Conclusions The pedicled TRAM flap using the whole muscle with partial sheath sparing technique in the present study is consistent with the results from previous studies in flap complication rates and oncological outcomes. PMID:27563562

  10. Calculation of the longitudinal aerodynamic characteristics of upper-surface-blown wing-flap configurations

    NASA Technical Reports Server (NTRS)

    Mendenhall, M. R.; Spangler, S. B.

    1978-01-01

    An engineering method for predicting the longitudinal aerodynamic characteristics of wing-flap configurations with upper surface blowing (USB) was developed. Potential flow models were incorporated into the prediction method: a wing and flap lifting surface model and a jet wake model. The wing-flap model used a vortex-lattice to represent the wing and flaps. The wing had an arbitrary planform and camber and twist, and the flap system was made up of a Coanda flap and other flap segments of arbitrary size. The jet wake model consisted of a series of closely spaced rectangular vortex rings. The wake was positioned such that it was tangent to the upper surface of the wing and flap between the exhaust nozzle and the flap trailing edge. It was specified such that the mass, momentum, and spreading rates were similar to actual USB jet wakes. Comparisons of measured and predicted pressure distributions, span load distributions, and total lift and pitching-moment coefficients on swept and unswept USB configurations are included. A wide range of thrust coefficients and flap deflection angles were considered at angles of attack up to the onset of stall.

  11. Development of an Extracorporeal Perfusion Device for Small Animal Free Flaps

    PubMed Central

    Fichter, Andreas M.; Ritschl, Lucas M.; Borgmann, Anna; Humbs, Martin; Luppa, Peter B.; Wolff, Klaus-Dietrich; Mücke, Thomas

    2016-01-01

    Background Extracorporeal perfusion (ECP) might prolong the vital storage capabilities of composite free flaps, potentially opening a wide range of clinical applications. Aim of the study was the development a validated low-cost extracorporeal perfusion model for further research in small animal free flaps. Methods After establishing optimal perfusion settings, a specially designed extracorporeal perfusion system was evaluated during 8-hour perfusion of rat epigastric flaps followed by microvascular free flap transfer. Controls comprised sham-operation, ischemia and in vivo perfusion. Flaps and perfusate (diluted blood) were closely monitored by blood gas analysis, combined laser Doppler flowmetry and remission spectroscopy and Indocyanine-Green angiography. Evaluations were complemented by assessment of necrotic area and light microscopy at day 7. Results ECP was established and maintained for 8 hours with constant potassium and pH levels. Subsequent flap transfer was successful. Notably, the rate of necrosis of extracorporeally perfused flaps (27%) was even lower than after in vivo perfusion (49%), although not statistically significant (P = 0,083). After sham-operation, only 6% of the total flap area became necrotic, while 8-hour ischemia led to total flap loss (98%). Angiographic and histological findings confirmed these observations. Conclusions Vital storage capabilities of microvascular flaps can be prolonged by temporary ECP. Our study provides important insights on the pathophysiological processes during extracorporeal tissue perfusion and provides a validated small animal perfusion model for further studies. PMID:26808996

  12. Multiple-digit resurfacing using a thin latissimus dorsi perforator flap.

    PubMed

    Kim, Sang Wha; Lee, Ho Jun; Kim, Jeong Tae; Kim, Youn Hwan

    2014-01-01

    Traumatic digit defects of high complexity and with inadequate local tissue represent challenging surgical problems. Recently, perforator flaps have been proposed for reconstructing large defects of the hand because of their thinness and pliability and minimal donor site morbidity. Here, we illustrate the use of thin latissimus dorsi perforator flaps for resurfacing multiple defects of distal digits. We describe the cases of seven patients with large defects, including digits, circumferential defects and multiple-digit defects, who underwent reconstruction with thin latissimus dorsi perforator flaps between January 2008 and March 2012. Single-digit resurfacing procedures were excluded. The mean age was 56.3 years and the mean flap size was 160.4 cm(2). All the flaps survived completely. Two patients had minor complications including partial flap loss and scar contracture. The mean follow-up period was 11.7 months. The ideal flap for digit resurfacing should be thin and amenable to moulding, have a long pedicle for microanastomosis and have minimal donor site morbidity. Thin flaps can be harvested by excluding the deep adipose layer, and their high pliability enables resurfacing without multiple debulking procedures. The latissimus dorsi perforator flap may be the best flap for reconstructing complex defects of the digits, such as large, multiple-digit or circumferential defects, which require complete wrapping of volar and dorsal surfaces.

  13. Analysis of Microvascular Free Flap Failure Focusing on the Microscopic Findings of the Anastomosed Vessels.

    PubMed

    Seo, Mi Hyun; Kim, Soung Min; Huan, Fan; Myoung, Hoon; Lee, Jong Ho; Lee, Suk Keun

    2015-10-01

    Microvascular flap reconstruction is known as successful technique, although vascular thrombosis can cause free flap failure. To analyze the histologic characteristics and causes of free flap failure, this clinical study examined failed free flaps, including the microanastomosed sites. This study included a total of 5 failed flaps, including 3 radial forearm free flaps, 1 latissimus dorsi free flap, and 1 fibular free flap, all performed with microvascular reconstruction surgery from 2009 to 2011 at Seoul National University Dental Hospital. At the resection surgeries of the failed nonviable flaps, histologic specimens including the microanastomosed vessels were acquired. For light microscope observation, the slides were stained with hematoxylin and eosin (HE), and also with Masson trichrome. Selected portions of graft tissue were also observed under transmission electron microscope (TEM). It was found that the cause of flap failure was the occlusion of vessels because of thrombi formation. During the microanastomosis, damage to the vessel endothelium occurred, followed by intimal hyperplasia and medial necrosis at the anastomosed site. In the TEM findings, some smooth muscle cells beneath endothelium were atrophied and degenerated. The formation of thrombi and the degeneration of the smooth muscle cells were coincident with vascular dysfunction of graft vessel. The damaged endothelium and the exposed connective tissue elements might initiate the extrinsic pathway of thrombosis at the microanastomotic site. Therefore, it is suggested that accurate surgical planning, adequate postoperative monitoring, and skillful technique for minimizing vascular injury are required for successful microvascular transfer.

  14. PIV study of near-field tip vortex behind perforated Gurney flaps

    NASA Astrophysics Data System (ADS)

    Lee, T.

    2011-02-01

    The impact of Gurney flaps, of different heights and perforations, on the growth and development of a tip vortex, both along the tip and in the near field of a finite NACA 0012 wing, at Re = 1.05 × 105 was investigated by using particle image velocimetry (PIV). Wind-tunnel force balance measurements were also made to supplement the PIV results. This study is a continuation of the work of Lee and Ko (Exp Fluids 46(6):1005-1019, 2009) on the near-wake measurements behind perforated Gurney flaps. The present results show that along the tip, the overall behavior of the secondary vortices and their interaction with the primary, or tip, vortex remained basically unchanged, regardless of flap height and perforation. The peak vorticity of the tip vortex, however, increased with flap height and always exhibited a local maximum at x/ c = 0.8 (from the leading edge). In the near field, the strength and structure of the near-field tip vortex were found to vary greatly with the flap height and perforation. The small flaps produced a more concentrated tip vortex with an increased circulation, while the large Gurney flaps caused a disruption of the tip vortex. The disrupted vortex can, however, be re-established by the addition of flap perforation. The larger the flap perforation the more organized the tip vortex. The Gurney flaps have the potential to serve as an alternative off-design wake vortex control device.

  15. Changes of perfusion of microvascular free flaps in the head and neck: a prospective clinical study.

    PubMed

    Mücke, Thomas; Rau, Andrea; Merezas, Andreas; Kanatas, Anastasios; Mitchell, David A; Wagenpfeil, Stefan; Wolff, Klaus-Dietrich; Steiner, Timm

    2014-11-01

    Reconstruction with a free flap is routine in head and neck surgery. However, reliable assessment of perfusion can be difficult, so we prospectively evaluated it in 4 types of microvascular free flaps in the oral cavity (n=196) and assessed differences in blood flow by non-invasive monitoring with a laser Doppler flowmetry unit. We measured oxygen saturation, haemoglobin concentration, and velocity on the surface of the flap preoperatively at the donor site, and on the flap on the first, second, and seventh postoperative days, and after 4 weeks in 186/196 patients, mean (SD) age of 60 (13) years. We studied the radial forearm (n=76, 41%), fibular (n=45, 24%), anterolateral thigh (n=53, 28%), and soleus perforator (n=12, 7%) flaps. The values for the radial forearm flap differed significantly from the others. There were significant differences in haemoglobin concentrations between the fibular and soleus perforator flaps, and between the anterolateral thigh and soleus perforator flaps (p=0.002 each). Free flaps are unique in the way that perfusion develops after microvascular anastomoses. Knowledge of how each flap is perfused may indicate different patterns of healing that could potentially influence long term rehabilitation and detection of future deficits in perfusion.

  16. Anatomical Basis and Clinical Application of Synovial Flaps in the Wrist and Distal Forearm.

    PubMed

    Colen, David L; Yeh, Jiun-Ting; Colen, Lawrence B

    2017-01-12

    Neuropathic symptoms after median nerve repair at the wrist or secondary to refractory carpal tunnel syndrome may become debilitating. These symptoms develop due to perineural adhesions, intraneural fibrosis and fixation of the nerve to the transverse carpal ligament after surgery and often require neurolysis. Interposition of vascularized soft tissue over the median nerve at the time of neurolysis prevents recurrence of such adhesions. The synovial flap, fashioned from the synovial lining of the flexor tendon sheath, is an ideal tissue for this purpose. Previous authors have described the surgical technique of the synovial flap, but the anatomical basis and design of the flap have not been previously discussed.Twenty fresh cadaver upper extremities were injected with microfil in order to analyze the arterial anatomy, flap dimensions and arc of rotation of the flexor tendon synovium mobilized as a flap suitable for coverage of the median nerve at the wrist. We determined that both radial and ulnar based flaps are clinically useful for providing coverage in the wrist and distal forearm. This flap was used in eighteen patients with complicated median nerve lesions in this region. All patients had an uncomplicated postoperative course. Of thirteen patients treated for post-traumatic median nerve neuromas, all but two had significant resolution of symptoms. When used as a vascularized flap, the flexor tendon synovium provides adequate protection of the median nerve. Flap dimensions and vascularity of this tissue make it an ideal local flap option when performing reoperative surgery on the median nerve.

  17. Systematic Review and Operative Technique of Recalcitrant Pressure Ulcers Using a Fillet Flap Technique

    PubMed Central

    Rao, Venkat K.

    2016-01-01

    Background: The purpose of this article is to describe the indications, operative technique, outcomes, and systematic review of the literature on the reconstruction of patients with end-stage pressure ulcers using a fillet flap technique. In this technique, the femur, tibia, and fibula are removed from the thigh and leg, and the soft tissue is used as a pedicled, or free, myocutaneous flap for reconstruction. Long-term outcomes, salient surgical technique of flap elevation, and design are detailed for patients who had a fillet of leg flap for reconstruction of extensive pressure ulcers. Methods: The indications, surgical technique, and postoperative outcomes of 5 patients who had pedicled fillet flaps are reviewed including patient age, sex, underlying comorbidities, duration of paraplegia, operative technique, and complications. A systematic review of the literature was performed searching PubMed, Cochrane Database, and Medline with the following MeSH terms: pressure ulcer, pressure sore, decubitus ulcer, fillet flap, and fillet flap. Inclusion criteria were use of a fillet technique, article data on the number of reconstructions before fillet flap, complications, and English language. Results: Most of our patients were male 75% (n = 3) with an average age of 47.5 years, had been paralyzed for an average of 16 years, and had few medical comorbidities. Two patients (3 flaps) required hip disarticulation, 1 patient had a bilateral fillet flaps, and 3 patients had resection of tibia/fibula. After following patients for an average of 1.4 years (4 mo to 2 yr), complications were limited to 1 patient who had partial-thickness flap loss at the distal skin flap that healed by secondary intention and 1 patient who had ulcer recurrence because of noncompliance. Four articles met inclusion criteria for systematic review and 3 were excluded. Conclusions: The fillet of leg flap remains a useful and reliable method of reconstructing end-stage pressure ulcers. PMID:27622082

  18. Results of Free Flap Reconstruction After Ablative Surgery in the Head and Neck

    PubMed Central

    Kim, Heejin; Jeong, Woo-Jin

    2015-01-01

    Objectives Due to the complex anatomy and function of the head and neck region, the reconstruction of ablative defects in this area is challenging. In addition, an increasing interest in improving the quality of life of patients and achieving good functional results has highlighted the importance of free flaps. The aim of this study was to summarize the results of free flap reconstruction and salvage of free flaps in a single institute, and to analyze differences in the results by the flap donor site, recipient site, and learning curve. Methods The medical records of patients who underwent free flap reconstruction from 2004-2012 were reviewed retrospectively. One hundred and fifty free flaps were used in 134 patients, who had an average age of 57.7 years. The types of flaps applied, primary defect sites, success rates, results of salvage operations for compromised flap, and the learning curve were analyzed. Results The anterolateral thigh flap was preferred for the reconstruction of head and neck defects. The overall success rate was 90.7%, with 14 cases of failure. A total of 19 salvage operations (12.7%) for compromised flap were performed, and 12 flaps (63.2%) were salvaged successfully. Dependency on the facial vessels as recipient vessels was statistically different when oral and oropharyngeal defects were compared to hypopharyngeal and laryngeal defects. The learning curve for microvascular surgery showed decrease in the failure rate after 50 cases. Conclusion The free flap technique is safe but involves a significant learning period and requires careful postoperative monitoring of the patient. Early intervention is important for the salvage of free flaps and for lowering the failure rate. PMID:26045917

  19. Predictive Capability of Near-Infrared Fluorescence Angiography in Submental Perforator Flap Survival

    PubMed Central

    Matsui, Aya; Lee, Bernard T.; Winer, Joshua H.; Laurence, Rita G.; Frangioni, John V.

    2010-01-01

    Background Perforator flaps have become increasingly popular in reconstructive surgery as patients experience less donor-site morbidity than with conventional musculocutaneous flaps. Previously, our laboratory described the intraoperative use of near-infrared (NIR) fluorescence angiography for patient-specific perforator-flap design. This study evaluates the predictive capability of NIR fluorescence angiography for flap survival in submental flap reconstruction. Methods NIR angiography was performed using indocyanine green at 0, 0.5, 24, 48, and 72 h post-surgery after flap creation in 12 pigs. A single perforator artery was preserved during flap creation based on location (central or non-central) and dominance (dominant or non-dominant). Venous drainage, arterial perfusion, and perfused area as percentage of total flap were analyzed. Clinical assessments of perfusion were compared with those made using NIR imaging and histology. Results Use of NIR fluorescence angiography immediately after flap creation accurately predicted areas of perfusion at 72 h (p = 0.0013), compared to the initial clinical assessment (p = 0.3085). Identification of necrosis by histology at 72 h correlated with NIR findings of insufficient arterial perfusion immediately after flap creation. No statistically significant differences in perfusion metrics were detected based on location or dominance of the preserved perforator; however, flaps containing central perforators had a higher percent perfused area than those with non-central perforators. Conclusions The use of NIR angiography immediately after flap creation can predict areas of perfusion at 72 h. This predictive capability may permit intraoperative revision of compromised flaps that have a high likelihood of failure. PMID:21042109

  20. Survey of wing and flap lower-surface temperatures and pressures during full-scale ground tests of an externally blown flap system

    NASA Technical Reports Server (NTRS)

    Hughes, D. L.

    1972-01-01

    Full-scale ground tests of an externally blown flap system were made using the wing of an F-111B airplane and a CF700 engine. Pressure and temperature distributions were determined on the undersurface of the wing, vane, and flap for two engine exhaust nozzles (conical and daisy) at several engine power and engine/wing positions. The tests were made with no airflow over the wing. The leading-edge wing sweep angle was fixed at 26 deg, the angle of incidence between the engine and the wing was fixed at 3 deg, and the tests were conducted with the flap retracted, extended and deflected 35 deg, and extended and deflected 60 deg. The integrated local pressures on the undersurface of the flap produced loads approximately three times as great at the 60 deg flap position as at the 35 deg flap position. With both nozzle configurations, more than 90 percent of the integrated pressure loads were contained within plus or minus 20 percent of the flap span centered around the engine exhaust centerline. The maximum temperature recorded on the flaps was 218 C (424 F) for the conical nozzle and 180 C (356 F) for the daisy nozzle.

  1. Free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps for breast reconstruction: a systematic review of flap complication rates and donor-site morbidity.

    PubMed

    Sailon, Alexander M; Schachar, Jeffrey S; Levine, Jamie P

    2009-05-01

    Free transverse rectus abdominis myocutaneous and deep inferior epigastric perforator flaps represent increasingly popular options for breast reconstruction. Although several retrospective, small-scale studies comparing these flaps have been published, most have failed to find a significant difference in flap complication rates or donor-site morbidity. We systematically reviewed the current literature, and subsequently pooled and analyzed data from included studies. Included studies reported flap complications and/or donor site morbidities for both flap types. Eight studies met the inclusionary criteria. For flap complications, there was a statistically significant difference between deep inferior epigastric perforator and free transverse rectus abdominis myocutaneous flaps in fat necrosis rates (25.5 +/- 0.49 vs. 11.3% +/- 0.41%, P < 0.001) and total necrosis rates (4.15 +/- 0.08 vs. 1.59% +/- 0.08%, P = 0.044). Partial necrosis rates were not statistically significant (3.54 +/- 0.07 vs. 1.60% +/- 0.07%, P = 0.057). For donor-site morbidity, there was no statistically significant difference in abdominal bulge (8.07 +/- 0.23 vs. 11.25% +/- 0.29%, P = 0.28). Multicenter, prospective studies are needed to further investigate differences between these flap options.

  2. Outcomes of Anatomic Reconstruction of Gunshot-Inflicted Lower Face Defects by Free Osteoseptocutaneous Fibula Flap and Expanded or Nonexpanded Temporal Scalp Flap Combination in Males.

    PubMed

    Eser, Cengiz; Gencel, Eyüphan; Kesiktaş, Erol; Yavuz, Metin

    2016-07-01

    Reconstruction of gunshot-inflicted composite lower face defects is a challenge for plastic surgeons. Functional and aesthetic repair of such defects mostly requires free or pedicled flap applications or combinations of both.In this study, the authors evaluated 7 males with gunshot-inflicted composite mandibular defects. All patients underwent reconstruction with a free osteoseptocutaneous fibula flap (FOCF) for the composite mandibular defect and a pre or nonexpanded temporal artery-based scalp flap for beardless facial skin. All patients were evaluated aesthetically and functionally with a postoperative evaluation scale. Average patient follow-up time was 3.5 years.All FOCFs survived completely. Expander exposition was observed in 2 preexpanded temporal scalp flaps. The problem was solved by rapid expansion and early flap application. All patients had acceptable functional and aesthetic results.In conclusion, the scalp flap should be considered in male beardless skin reconstruction due to its ease of application, reliability, and proximity to the defect. Preexpansion of this flap can decrease donor area morbidities. Moreover, the FOCF and scalp flap combination is a convenient procedure for gunshot-inflicted lower face defects, and such procedures produce good aesthetic and functional long-term outcomes.

  3. Improved technique for evaluating oral free flaps by pinprick testing assisted by indocyanine green near-infrared fluorescence angiography.

    PubMed

    Nagata, Tetsuji; Masumoto, Kazuma; Uchiyama, Yoshiyuki; Watanabe, Yoshiko; Azuma, Ryuichi; Morimoto, Yuji; Katou, Fuminori

    2014-10-01

    In head and neck surgery, free-flap reconstruction using a microvascular anastomosis is an indispensable option after tumor ablation. Because the success of free-flap reconstruction is enhanced by rapid identification and salvage of failing flaps, postoperative monitoring of free flaps is essential. We describe a new technique using indocyanine green (ICG) near-infrared angiography and pinprick testing to monitor intraoral free flaps. A solution of ICG (Diagnogreen, 5 ml) was intravenously injected, and scanning was performed with a near-infrared video camera system. Thirty seconds after ICG injection, a pinprick test was performed by placing a 24-gage needle through the dermis to the subcutaneous fat of the flap. Pinprick testing during ICG fluorescence imaging was performed in 30 patients. Flap perfusion was confirmed in all patients, and all flaps survived postoperatively. ICG fluorescence imaging demonstrated that flap perfusion was maintained.

  4. Distally based venous flap: a new technique for the correction of syndactyly without skin graft in adult patients.

    PubMed

    Cil, Yakup; Kocman, Atacan Emre; Yapici, Abdul Kerim

    2009-12-01

    Skin grafts and local flaps are conventional methods for repairing simple syndactyly. Skin grafts usually leave unsightly appearance and contracture formation. In this study, unipedicled distally based venous flap were raised from third or fourth metacarpal area of the hand for syndactyly treatment. The distally based venous flap was to provide skin coverage to one side of the finger, in order to avoid complications arising from using skin graft. Nine patients' syndactylies (5 simple incomplete and 4 simple complete syndactyly) were treated using this method. The mean follow-up period of the flaps was 14 months, ranging from 12 to 16 months. Mild edema and venous congestion occurred in all flaps. Superficial necrosis involving two flaps did not affect flap survival. All flaps survived completely. In this article, we have described a new surgical technique for the correction of syndactyly in a single surgical procedure that utilizes a distally based venous flap to provide skin coverage without skin graft.

  5. Combined Use of an Anterolateral Thigh Flap and Superficial Inferior Epigastric Artery Flap for Reconstruction of an Extensive Abdominal Wall Defect

    PubMed Central

    Kagaya, Yu; Arikawa, Masaki; Kobayashi, Eisuke

    2016-01-01

    Summary: Reconstruction of large abdominal wall defects is challenging. We herein report the successful reconstruction of an extensive abdominal wall defect using a novel combination of flaps after sarcoma resection. A 74-year-old man presented with a dedifferentiated liposarcoma on his abdominal wall. He underwent excision of the tumor, which resulted in an extensive abdominal wall defect. The defect was reconstructed with a pedicled anterolateral thigh flap with an iliotibial tract and a pedicled superficial inferior epigastric artery flap. No skin graft was necessary. The wounds healed successfully, and no herniation occurred. The combination of an anterolateral thigh flap and a superficial inferior epigastric artery flap is a versatile option for reconstruction of extensive abdominal wall defects. PMID:27975026

  6. Wind tunnel tests of the GA(W)-2 airfoil with 20% aileron, 25% slotted flap, 30% Fowler flap and 10% slot-lip spoiler

    NASA Technical Reports Server (NTRS)

    Wentz, W. H., Jr.

    1977-01-01

    Two dimensional wind tunnel tests were conducted for the GA(W)-2 airfoil section with: 20% aileron, 25% slotted flap; 30% Fowler flap, and 10% slot-lip spoiler. All tests were conducted at a Reynolds number of 2,200,000 and a Mach Number of 0.13. In addition to force measurements, tuft studies were conducted for the slotted and Fowler flap configurations. Aileron and spoiler hinge moments were obtained by integration of surface pressure measurements. Tests results show that a value of 3.82 was obtained with 30% Fowler flap. Aileron control effectiveness and hinge moments were similar to other airfoils. The slot-lip spoiler provided powerful, positive roll control at all flap settings.

  7. A "watch window" technique for monitoring buried free jejunum flaps during circumferential pharyngolaryngectomy reconstruction.

    PubMed

    Li, Quan; Zhang, Xin-Rui; Liu, Xue-Kui; Zhang, Zhi-Gang; Liu, Wei-Wei; Li, Hao; Guo, Zhu-Ming

    2012-07-01

    The free jejunum flap approach is the optimal option for circumferential pharyngolaryngectomy reconstruction. In this study, we designed a "watch window" for monitoring buried free jejunum flaps, thereby allowing us to assess graft viability. From 2007 to 2011, 14 patients with hypopharyngeal cancer underwent circumferential pharyngolaryngectomy that was reconstructed using a free jejunum flap at the Sun Yat-sen University Cancer Centre. During the closing of the neck incision, a "watch window" was designed for postoperative monitoring. Two patients experienced thrombosis of the pedicle. One was detected early and successfully rescued by removal of the thrombosis, the other one managed with a second free jejunum flap. The success rate of the buried flaps was 92.9%. No pharyngocutaneous fistulas or strictures occurred. All patients eventually resumed oral feeding and swallowing. The "watch window" technique for monitoring buried free jejunum flaps is simple, reliable and useful for finding vascular problems. Level of evidence Case series.

  8. Versatility of Abbe-Estlander Flap in Lip Reconstruction – A Prospective Clinical Study

    PubMed Central

    Shetty, Premlatha M; Bhambar, Rohan Suhas; Gattumeedhi, Shashank Redddy; Kumar, Ram Mohan; Kumar, Harsh

    2014-01-01

    Aims & Objectives: Aim of this study was to evaluate the versatility of Abbe-Estlander flap in lip reconstruction with regard to function and aesthetic outcome and objectives were to present our experience and result in series of 10 cases of lip reconstruction by Abbe-Estlander flap. Materials and Methods: A total number of 10 patients were taken up in the study, age ranging from 35-71 y, mean age being 60. Out of 10 patients, 6 (60%) were male and 4 (40%) female. In all these patients, Abbe-Estlander flap that involved the commissure was used for reconstruction. Patients were recalled at intervals of three weeks, three months and six months for follow up. Results: All patients had satisfactory results in terms of aesthetic and functional outcome. Conclusion: Abbe-Estlander flap is safe and a reliable flap which is technically simple to perform, and provides functionally and aesthetically pleasing result and affords versatility in flap design. PMID:25478393

  9. Analysis of a Multi-Flap Control System for a Swashplateless Rotor

    NASA Technical Reports Server (NTRS)

    Sekula, Martin K.; Wilbur, Matthew L.

    2011-01-01

    An analytical study was conducted examining the feasibility of a swashplateless rotor controlled through two trailing edge flaps (TEF), where the cyclic and collective controls were provided by separate TEFs. This analysis included a parametric study examining the impact of various design parameters on TEF deflections. Blade pitch bearing stiffness; blade pitch index; and flap chord, span, location, and control function of the inboard and outboard flaps were systematically varied on a utility-class rotorcraft trimmed in steady level flight. Gradient-based optimizations minimizing flap deflections were performed to identify single- and two-TEF swashplateless rotor designs. Steady, forward and turning flight analyses suggest that a two-TEF swashplateless rotor where the outboard flap provides cyclic control and inboard flap provides collective control can reduce TEF deflection requirements without a significant impact on power, compared to a single-TEF swashplateless rotor design.

  10. Closure of difficult palatal fistulas using a "parachuting and anchoring" technique with the tongue flap.

    PubMed

    Elyassi, Ali R; Helling, Eric R; Closmann, James J

    2011-12-01

    The tongue flap has been described in reconstructing palatal defects. Nevertheless, properly securing the flap to the palatal defect has continued to pose a challenge, especially because the flap becomes mobile with normal activities (i.e., speech and swallow). For this reason, alternative fixation schemes have been discussed in literature, but do not always solve the problem. In this article, we offer an alternative method for positioning and securing the tongue flap into the palatal defect. The authors of this article believe that advantages of this technique include an increase in flap security and immobility and a decrease in postoperative maxillomandibular fixation requirement. Although unanswered questions still remain regarding improved flap retention with this method, we believe that the "parachuting and anchoring" technique provides an alternative method that can most definitely add to the surgeon's armamentarium.

  11. Localized, Non-Harmonic Active Flap Motions for Low Frequency In-Plane Rotor Noise Reduction

    NASA Technical Reports Server (NTRS)

    Sim, Ben W.; Potsdam, Mark; Kitaplioglu, Cahit; LeMasurier, Philip; Lorber, Peter; Andrews, Joseph

    2012-01-01

    A first-of-its-kind demonstration of the use of localized, non-harmonic active flap motions, for suppressing low frequency, in-plane rotor noise, is reported in this paper. Operational feasibility is verified via testing of the full-scale AATD/Sikorsky/UTRC active flap demonstration rotor in the NFAC's 40- by 80-Foot anechoic wind tunnel. Effectiveness of using localized, non-harmonic active flap motions are compared to conventional four-per-rev harmonic flap motions, and also active flap motions derived from closed-loop acoustics implementations. All three approaches resulted in approximately the same noise reductions over an in-plane three-by-three microphone array installed forward and near in-plane of the rotor in the nearfield. It is also reported that using an active flap in this localized, non-harmonic manner, resulted in no more that 2% rotor performance penalty, but had the tendency to incur higher hub vibration levels.

  12. Free radial forearm flap versatility for the head and neck and lower extremity

    SciTech Connect

    Chicarilli, Z.N.; Ariyan, S.; Cuono, C.B.

    1986-07-01

    Microsurgical techniques have developed numerous territories suitable for free tissue transfer. However, the demand for thin cutaneous resurfacing limits the choice of flaps available to the reconstructive microsurgeon. The radial forearm flap is a thin, axial, fasciocutaneous flap, offering pliable cutaneous resurfacing, with or without sensation. We have used 15 flaps to reconstruct defects in the head and neck and lower extremity resulting from burns, blunt and avulsive trauma, radiation necrosis, and tumor ablation. Two flaps (15 percent) developed venous congestion and were salvaged by reoperation. One retrograde flap (7.5 percent) developed partial necrosis from arterial insufficiency. Neural re-innervation was successful in two out of three patients in whom it was attempted. Two patients (15%) sustained minor donor site skin graft loss that healed secondarily. In our series of predominantly older patients the donor sites have been relatively inconspicuous at one year follow-up. A functional restoration was achieved in all patients.

  13. Thermal injury in TAPIA breast reconstruction—thermal injury to thoracodorsal artery perforator flap

    PubMed Central

    Børsen-Koch, Mikkel; Gunnarsson, Gudjon L.; Sørensen, Jens Ahm

    2017-01-01

    This paper presents two case reports on thermal injury to a breast reconstructed by the TAPIA method. In both cases the injuries were caused by excessive sun exposure. Thermal injury to flaps used in breast reconstruction has previously been described but most commonly in abdominal flaps, which may be due to the relative high frequency of this type of reconstructions. Reports of thermal injury to reconstructions using the Latissimus Dorsi flap are rare. The injuries previously described are most often caused by severe heat exposure. The thoracodorsal artery perforator (TAP)-flap can be used as an alternative to the Latissimus Dorsi flap but it may be more susceptible to thermal insult due to the total denervation, the restricted blood supply and the limited thickness of the flap. Precautions are recommended to avoid this type of injury. PMID:28210561

  14. Wind-tunnel investigation of a Fowler flap and spoiler for an advanced general aviation wing

    NASA Technical Reports Server (NTRS)

    Paulson, J. W., Jr.

    1976-01-01

    The wing was tested without fuselage or empennage and was fitted with approximately three-quarter span Fowler flaps and half span spoilers. The spoilers were hinged at the 70 percent chord point and vented when the flaps were deflected. Static longitudinal and lateral aerodynamic data were obtained over an angle of attack range of -8 deg to 22 deg for various flap deflections and positions, spoiler geometries, and vent lip geometries. Lateral characteristics indicate that the spoilers are generally adequate for lateral control. In general, the spoiler effectiveness increases with increasing angle of attack, increases with increasing flap deflections, and is influenced by vent lip geometry. In addition, the data show that some two-dimensional effects on spoiler effectiveness are reduced in the three-dimensional case. Results also indicate significant increase in lift coefficient as the Fowler flaps are deflected; when the flap was fully deflected, the maximum wing lift coefficient was increased about 96 percent.

  15. Current sheet flapping motions in the tailward flow of magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Wu, Mingyu; Lu, Quanming; Volwerk, Martin; Vörös, Zoltán.; Ma, Xuanye; Wang, Shui

    2016-08-01

    The feature and origin of current sheet flapping motions are one of most interesting issues of magnetospheric dynamics. In this paper we report the flapping motion of the current sheet detected in the tailward flow of a magnetic reconnection event on 7 February 2009. This flapping motion with frequency about 12 mHz was accompanied by magnetic turbulence. The observations by the tail-elongated fleet of five Time History of Events and Macroscale Interactions during Substorms probes indicate that these flapping oscillations were rather confined within the tailward flow than were due to a global process. This flapping motion could be due to the instability driven by the free energy associated with the ion temperature anisotropy in the tailward flow. Our observations indicate that the flapping motion in the tailward flow could have a different generation mechanism with that in the earthward flow.

  16. Tests of a Gust-alleviating Flap in the Gust Tunnel

    NASA Technical Reports Server (NTRS)

    Donely, Philip; Shufflebarger, C C

    1940-01-01

    Tests were made to determine the effectiveness of a long-period dynamically overbalanced flap in reducing airplane accelerations due to atmospheric gusts. For two gust shapes, one gust velocity, one forward velocity, and one wing loading, a series of flights was made with the flap locked and was then repeated with the flap free to operate. The records were evaluated by routine methods. The results indicate that the flap reduced the maximum acceleration increment 39 percent for a severe gust but with a representative gust shape (a sharp-edge gust), the reduction was only 3 percent. The results also indicate that the flap tended to reduce the longitudinal stability of the airplane. Computations made of the effectiveness and the action of the flap were in good agreement with the experimental results.

  17. Flap survey test of a combined surface blowing model: Flow measurements at static flow conditions

    NASA Technical Reports Server (NTRS)

    Fukushima, T.

    1978-01-01

    The Combined Surface Blowing (CSB) V/STOL lift/propulsion system consists of a blown flap system which deflects the exhaust from a turbojet engine over a system of flaps deployed at the trailing edge of the wing. Flow measurements consisting of velocity measurements using split film probes and total measure surveys using a miniature Kiel probe were made at control stations along the flap systems at two spanwise stations, the centerline of the nozzle and 60 percent of the nozzle span outboard of the centerline. Surface pressure measurements were made in the wing cove and the upper surface of the first flap element. The test showed a significant flow separation in the wing cove. The extent of the separation is so large that the flow into the first flap takes place only at the leading edge of the flap. The velocity profile measurements indicate that large spanwise (3 dimensional) flow may exist.

  18. Prophylactic cross-face nerve flap for muscle protection prior to facial palsy.

    PubMed

    Koshima, Isao; Narushima, Mitsunaga; Mihara, Makoto; Yamamoto, Yusuke; Iida, Takuya; Uchida, Gentaro

    2011-02-01

    The facial muscles of a 28-year-old woman with left acoustic neuroma were successfully protected with a vascularised cross-face nerve flap using a vascularised lateral femoral cutaneous nerve along with a perforator of the lateral circumflex femoral system. It was transferred as a vascularised cross-face nerve flap to bridge a 15-cm-long defect between the bilateral buccal branches. Three months after the nerve flap transfer, the total tumour including the facial nerve was resected. Postoperatively, rapid nerve sprouting through the nerve flap and excellent facial reanimation were obtained 3-6 months after resection. This method is a one-stage reconstruction procedure, has minimal donor-site morbidity and results in strong postoperative muscle contraction. To our knowledge, this is the first report on a prophylactic cross-face nerve flap technique for the protection of facial muscles before facial nerve transection, and also the usefulness of vascularised lateral femoral cutaneous nerve flap.

  19. Risk factors and therapeutic strategy after failure of free flap coverage for lower-limb defects.

    PubMed

    Perrot, Pierre; Bouffaut, Anne-Laure; Perret, Christophe; Connault, Jérôme; Duteille, Franck

    2011-03-01

    From 2004 to 2007, 148 limb free flaps were performed in a series of 138 patients at the University Hospital in Nantes, France. Flaps were successful in 127 instances (rate: 86%; group A) and failed in 21 (group B). An analysis of the various factors (pre-, intra-, and postoperative) in both groups that may have influenced the outcome of surgery identified the following: operating time, cold ischemia time, and the interval before reoperation. This report is based on our experience in managing 21 free flap failures during reconstructive surgery of the limbs. The causes of failure were analyzed, and possible therapeutic strategies defined (i.e., a second free flap procedure, a pedicle flap, coverage with artificial dermis, or amputation). In our opinion, careful analysis of the causes of flap failure is essential to an appropriate choice of subsequent therapeutic strategy.

  20. Digital reconstruction and donor site resurfacing: a two-flap technique.

    PubMed

    Kang, Qing-Lin; Chai, Yi-Ming; Chen, Weijia; Zeng, Bing-Fang

    2007-01-01

    Use of a great toe pulp flap is one of the methods to repair partial soft-tissue defect of the thumb or other digits. However, the conventional application of free skin grafts to close the donor site may bring donor-site morbidity. The authors present a two-flap technique that a reverse first dorsal metatarsal artery (FDMA) flap resurfaces the defect of the free great toe pulp flap. Six patients with soft-tissue defects of the thumbs or fingers were treated with this technique. Both the pulp and reverse flaps survived uneventfully after reconstruction of the thumbs and fingers. The reverse flap to resurface the donor site on the great toe was sensate and durable. Satisfactory appearance and function were gained in all patients. Results revealed that this technique can be accepted as an alternative method when treating soft tissue defect of the thumb or finger.

  1. Microvascular medial femoral condylar flaps in 107 consecutive reconstructions in the head and neck.

    PubMed

    Brandtner, Christian; Hachleitner, Johannes; Bottini, Gian Battista; Buerger, Heinz; Gaggl, Alexander

    2016-07-01

    We have assessed the role of the medial femoral condylar flap in 107 patients who had reconstructions of the head and neck. We retrospectively reviewed their medical records for indications, complications, and outcomes. The flap was primarily used for coverage of alveolar ridge defects (n=67), secondly for defects of the facial bone, calvaria, or skull base (n=35), and thirdly for partial laryngeal defects (n=5). Two flaps were lost. One patient fractured a femur 5 weeks postoperatively. The duration of follow up ranged from 6 months to 12 years. The medial femoral condylar flap is well-suited to individual reconstructions of the alveolar ridge, midface, calvaria, skull base, and part of the larynx with poor recipient sites. The flap does not replace other wellknown flaps, but offers new solutions for solving special problems in head and neck surgery.

  2. Free flaps in orbital exenteration: a safe and effective method for reconstruction.

    PubMed

    López, Fernando; Suárez, Carlos; Carnero, Susana; Martín, Clara; Camporro, Daniel; Llorente, José L

    2013-05-01

    The aim of this study was to investigate the course of reconstructive treatment and outcomes with use of free flaps after orbital exenteration for malignancy. Charts of patients who had free flap reconstruction after orbital exenteration were retrospectively reviewed and the surgical technique was evaluated. Demographics, histology, surgical management, complications, locoregional control, and survival were analyzed. We performed 22 flaps in 21 patients. Reconstruction was undertaken mainly with anterolateral thigh (56 %), radial forearm (22 %), or parascapular (22 %) free flaps. Complications occurred in 33 % of patients and the flap's success rate was 91 %. The 5-year locoregional control and survival rates were 42 and 37 %, respectively. Free tissue transfer is a reliable, safe, and effective method for repair of defects of the orbit and periorbital structures resulting from oncologic resection. The anterolateral thigh flap is a versatile option to reconstruct the many orbital defects encountered.

  3. [The role definition of lateral arm free flap in reconstruction after head and neck cancer surgery].

    PubMed

    Li, C; Cai, Y C; Wang, W; He, Y X; Lan, X J; Li, Q L; Zhou, Y Q; Liu, J F; Zhu, G Q; Liu, K; Wang, S X; Wang, K; Fan, J C; Sun, R H

    2016-02-01

    Application of free flap is one of the important repair means in head and neck surgery. A variety of free flaps, such as anterolateral thigh flap, have showed unique advantages in repair for tissue defects after resection of head and neck tumor, and have became increasing popularity. Lateral arm flee flap is an important repair means in plastic surgery, which has developed more than 30 years, but the application of this flap for reconstruction in head and neck surgery is relatively backward, with few reports. This review focuses on the creativity and innovation, the relationship between anatomy and clinical application, and the application status and prospects for lateral arm flee flap in individual head and neck reconstruction surgery.

  4. Free Flap Salvage after Recurrent Venous Thrombosis by Means of Large-Scale Treatment with Medical Leeches

    PubMed Central

    Fujiki, Masahide; Arikawa, Masaki; Kagaya, Yu; Miyamoto, Shimpei

    2016-01-01

    Summary: An anterolateral thigh flap was salvaged using 110 medical leeches in the absence of an available vein for reanastomosis. After surgical construction of the flap for full-thickness thoracic wall reconstruction, the patient developed complete venous occlusion. Specifically, the anastomotic vein developed complete occlusion, and the internal jugular vein had a thrombus. In addition, because the lung was posterior to the flap, the angiogenic area of the flap was very small. When the medical leeches were first applied, the flap showed prominent venous congestion. However, the congestion began to resolve by day 6 of leech use, leading to complete survival of the flap. PMID:28293509

  5. Tests in the variable-density wind tunnel of the NACA 23012 airfoil with plain and split flaps

    NASA Technical Reports Server (NTRS)

    Abbott, Ira H; Greenberg, Harry

    1939-01-01

    Section characteristics for use in wing design are presented for the NACA 23012 airfoil with plain and split flaps of 20 percent wing chord at a value of the effective Reynolds number of about 8,000,000. The flap deflections covered a range from 60 degrees upward to 75 degrees downward for the plain flap and from neutral to 90 degrees downward for the split flap. The split flap was aerodynamically superior to the plain flap in producing high maximum lift coefficients and in having lower profile-drag coefficients at high lift coefficients.

  6. Tertiary resurfacing after one of the first free flaps in Europe, a reflection on 30 years of microsurgical progress.

    PubMed

    Hart, A M; Tollan, C J; Dabernig, J; Acland, R; Taggart, I

    2007-01-01

    Free flaps have been used for over 30 years. During this period, improved anatomical understanding has increased donor options and available pedicle lengths, permitting safer, single-stage reconstructions with simpler anastomoses. Refinements, such as perforator flaps in particular, have greatly improved donor morbidity, recipient site cosmesis, and the ability to replace 'like with like' while retaining options for innervation. This case highlights the evolution from one of Europe's first free tissue transfers, effectively a perforator flap, through the advent of free muscle flaps to the current generation of contourable perforator flaps. Free flap transfer has become increasingly sophisticated, safer, and more predictable, yet the potential quality of reconstructive outcome has changed little.

  7. 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.

  8. Hemipelvectomy for Buttock Tumors Utilizing an Anterior Myocutaneous Flap of Quadriceps Femoris Muscle

    PubMed Central

    Sugarbaker, Paul H.; Chretien, Paul A.

    1983-01-01

    Hemipelvectomy utilizing an anterior myocutaneous flap is indicated for aggressive tumors of the buttock and proximal portion of the posterior thigh. A large operative defect created posteriorly by amputation of the lower extremity, hemipelvis, and buttock is covered by a myocutaneous flap of quadriceps femoris muscle and overlying skin and subcutaneous tissue. The superficial femoral artery is preserved to sustain the myocutaneous flap. ImagesFig. 2A,B,C.Fig. 2A,B,C. PMID:6848048

  9. Noise Radiation from a Continuous Mold-Line Link Flap Configuration

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, Thomas F.; Humphreys, William M., Jr.

    2011-01-01

    The results of an experimental study of the noise from a Continuous Mold-Line Link (CML) flap are presented. Acoustic and unsteady surface pressure measurements were performed on a main element wing section with a half-span CML flap in NASA Langley s Quiet Flow Facility. The acoustic data were acquired with a medium aperture directional array (MADA) of microphones. The Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) method is applied to determine the spatial distribution and strength of the noise sources over the surface of the test model. A Coherent Output Power (COP) method which relates the output from unsteady surface pressure sensors to the output of the MADA is also used to obtain more detailed characteristics of the noise source distribution in the trailing edge region of the CML. These results are compared to those obtained for a blunt flap to quantify the level of noise benefit that is achieved with the CML flap. The results indicate that the noise from the CML region of the flap is 5 to 17 dB lower (depending on flap deflection and Mach number) than the noise from the side edge region of the blunt flap. Lower noise levels are obtained for all frequencies. Spectral analysis of the noise from the cove region of the CML and blunt flap models also reveal a spectral peak in the high frequency range that is related to noise scattering at the trailing edge of the main element. The peaks in the CML and blunt flap cove noise spectra are close in level and often exceed blunt side edge noise. Applying a strip of serrated tape to the trailing edge of the CML flap model main airfoil reduced the peak but increased other noise somewhat. Directivity measurements show that the CML flap can be more directional than the blunt flap.

  10. Noise Radiation from a Continuous Mold-Line Link Flap Configuration

    NASA Technical Reports Server (NTRS)

    Hutcheson, Florence V.; Brooks, Thomas F.; Humphreys, William M.

    2008-01-01

    The results of an experimental study of the noise from a Continuous Mold-Line Link (CML) flap are presented. Acoustic and unsteady surface pressure measurements were performed on a main element wing section with a half-span CML flap in NASA Langley s Quiet Flow Facility. The acoustic data were acquired with a medium aperture directional array (MADA) of microphones. The Deconvolution Approach for the Mapping of Acoustic Sources (DAMAS) method is applied to determine the spatial distribution and strength of the noise sources over the surface of the test model. A Coherent Output Power (COP) method which relates the output from unsteady surface pressure sensors to the output of the MADA is also used to obtain more detailed characteristics of the noise source distribution in the trailing edge region of the CML. These results are compared to those obtained for a blunt flap to quantify the level of noise benefit that is achieved with the CML flap. The results indicate that the noise from the CML region of the flap is 5 to 17 dB lower (depending on flap deflection and Mach number) than the noise from the side edge region of the blunt flap. Lower noise levels are obtained for all frequencies. Spectral analysis of the noise from the cove region of the CML and blunt flap models also reveal a spectral peak in the high frequency range that is related to noise scattering at the trailing edge of the main element. The peaks in the CML and blunt flap cove noise spectra are close in level and often exceed blunt side edge noise. Applying a strip of serrated tape to the trailing edge of the CML flap model main airfoil, reduced the peak but increased other noise somewhat. Directivity measurements show that the CML flap can be more directional than the blunt flap.

  11. Distally Based Dorsal Digital Fasciocutaneous Flap for the Repair of Digital Terminal Amputation Defects

    PubMed Central

    Hou, Ruixing; Ju, Jihui; Zhao, Qiang; Liu, Yuefei

    2012-01-01

    The preferred plastic surgery regimen for distal digital segment wounds remains unknown, although multiple options are available for the repair. The purpose of this investigation is to study its anatomic rationale and clinical outcomes, in addition to the role of dorsal digital veins in digital reconstruction. Patients (n  =  765) suffering from digital terminal segment traumatic wounds (823 digits) were identified and reviewed in a retrospective manner. The wounds were repaired using distally based dorsal digital fasciocutaneous flaps with venoneuroadipofascial pedicles. Skin flaps survived in 818 digits (99.4%), whereas 5 flaps (0.6%) became partially necrotic. Postoperative follow-up data were available from 521 patients involving 559 digits, for an average duration of 10 months (range, 4–36 months). The wider pedicled fascial flap (1.0–1.5 cm) was significantly associated with a decreased occurrence of blebs, whereas the first few patients with pedicled fascial flaps 0.5 to 1.0 cm wide exhibited more frequent occurrence of blebs and flap contractures. The flaps retracted in size within the first 2 to 3 months at the rate of 10% compared with the intraoperative outlined size. The skin flaps became mildly pigmented within the first postoperative month, and at 6 months the flaps turned brighter in color, almost approximating the color of the normal digits. At 12 months, both the texture and appearance of the flaps were acceptable. The donor sites healed without any scar contracture. The digital terminals appeared grossly normal with acceptable digital function. Without any neural reconstruction, skin flap sensation was rated as S2 to S3+, whereas with neural reconstruction the 2-point discrimination sensitivity measured 4 to 9 mm. The use of a distally based dorsal digital fasciocutaneous flap with venoneuroadipofascial pedicle was a simple, safe, and less invasive regimen for repairing digital terminal segment wounds. PMID:23294073

  12. Self-propulsion of flapping bodies in viscous fluids: Recent advances and perspectives

    NASA Astrophysics Data System (ADS)

    Wang, Shizhao; He, Guowei; Zhang, Xing

    2016-12-01

    Flapping-powered propulsion is used by many animals to locomote through air or water. Here we review recent experimental and numerical studies on self-propelled mechanical systems powered by a flapping motion. These studies improve our understanding of the mutual interaction between actively flapping bodies and surrounding fluids. The results obtained in these works provide not only new insights into biolocomotion but also useful information for the biomimetic design of artificial flyers and swimmers.

  13. Cornerstones in reconstructive plastic surgery: Argentinian development of muscular, myocutaneous, and fasciocutaneous flaps.

    PubMed

    Kostianovsky, A S; Sostaric, N M

    1992-01-01

    This article pays tribute to two Argentinian surgeons whose work has been published in their local journals but is unknown internationally. Goldtraj's pioneering work on the treatment of vascular ulcers of the leg using a muscular flap, presented in 1954, and Spadafora's work on the treatment of tissue defects with myocutaneous and fasciocutaneous flaps, presented in 1964, are discussed. Both papers deserve a place among the pioneering contributions on the subject of muscular as well as myocutaneous and fasciocutaneous flaps.

  14. A Fluid Structure Interaction Strategy with Application to Low Reynolds Number Flapping Flight

    DTIC Science & Technology

    2010-01-01

    and CN(t) (force normal to stroke plane) with time for FSI calculation of flapping wing model in free longitudinal flight: (blue) RB1, (dashed...kinematics. The effects of wing flexibility are evaluated on the performance of a flapping , flexible airfoil. In three-dimensional studies most of the...scale flapping wing devices [91]. As the size of the vehicle and characteristic Reynolds number (Re) of the flow decrease, friction forces are

  15. An Investigation into Ground Effect for an Underwater Biologically Inspired Flapping Foil

    DTIC Science & Technology

    2014-01-01

    remains to be done to explore the benefit induced by flapping a foil close to a hard surface ground. iv Acknowledgements I would first like to...acknowledge that this research topic has been inspired by the flapping fins and wings of swimming and flying animals. While most of the literature in...the flapping frequency expressed in radians. Similarly, pitch motion can be described by: () = 0 cos() Equation 4. Equation for pitch

  16. Flapping Wing Technology for Micro Air Vehicles Incorporating a Lead Zirconate Titanate (PZT) Bimorph Actuator

    DTIC Science & Technology

    2012-06-01

    Flapping Wing Technology for Micro Air Vehicles Incorporating a Lead Zirconate Titanate (PZT) Bimorph Actuator by Asha J. Hall, Richard A...Laboratory Aberdeen Proving Ground, MD 21005 ARL-TR-6040 June 2012 Flapping Wing Technology for Micro Air Vehicles Incorporating a Lead Zirconate ...2011 to April 2012 4. TITLE AND SUBTITLE Flapping Wing Technology for Micro Air Vehicles Incorporating a Lead Zirconate Titanate (PZT) Bimorph

  17. A Fundamental Study in Nonlinear Aeroelastic Phenomena in Flapping Wing Micro Air Vehicles

    DTIC Science & Technology

    2008-11-30

    obtained from an updated Lagrangian approach for flapping wings with prescribed root motion that resembles insect or hummingbird wing flapping...which account for evolution of the wake, provide a reasonable approximation to the development of the unsteady wake during a flapping cycle. A two...condition at the leading edge. The evolution of the wake is governed by the Rott-Birkhoff equation, which is derived from the Biot-Savart law for two

  18. Tug 'O' war: challenges of transverse upper gracilis (TUG) myocutaneous free flap breast reconstruction.

    PubMed

    Locke, Michelle B; Zhong, Toni; Mureau, Marc A M; Hofer, Stefan O P

    2012-08-01

    Autologous tissue microsurgical breast reconstruction is increasingly requested by women following mastectomy. While the abdomen is the most frequently used donor site, not all women have enough abdominal tissue excess for a unilateral or bilateral breast reconstruction. A secondary choice in such women may be the transverse upper gracilis (TUG) myocutaneous flap. This study reviews our experience with TUG flap breast reconstruction looking specifically at reconstructive success rate and the requirement for secondary surgery. A total of 16 free TUG flaps were performed to reconstruct 15 breasts in eight patients over a period of five years. Data were collected retrospectively by chart review. Follow up ranged from 14 to 41 months. During the follow up period, there was one (6.3%) complete flap loss in an immediate breast reconstruction patient. Four further flaps (25%) failed in their primary aim of breast reconstruction, as they required additional significant reconstruction with either deep inferior epigastric perforator (DIEP) flaps (two flaps (12.5%), one patient) or augmentation with silicone breast implants (two flaps (12.5%), one patient), giving a successful breast reconstruction rate with the TUG flap of only 66.7%. In all of the remaining reconstructed breasts, deficient flap volume or breast contour was seen. Eight flaps were augmented by lipofilling. A total of 62.5% of the donor sites had complications, namely sensory disturbance of the medial thigh (25%) and poor scar (37.5%) requiring revision. This series demonstrates a high rate of reconstructive failure and unsatisfactory outcomes from TUG flap breast reconstruction. We feel this reinforces the necessity of adequate pre-operative patient assessment and counselling, including discussion regarding the likelihood of subsequent revisional surgery, before embarking on this form of autologous breast reconstruction.

  19. Microcapillary sign of flap alignment in femtosecond laser-assisted in situ keratomileusis

    PubMed Central

    Fawzy, Fathy; Wahba, Sherine S; Fawzy, Nader

    2016-01-01

    We present an observational sign that ensures perfect alignment during femtosecond laser-assisted in situ keratomileusis (FS LASIK). Alignment is assured when a microsponge is used to dry the flap and the area of dryness exceeds the area of direct touch of the microsponge. The area might even reach the whole circumference of the flap at the first touch. This sign of alignment can be explained by microcapillary action. This sign was not elicited in flaps created by a microkeratome. PMID:27799731

  20. Lower Lip Suspension Using Bilateral Temporalis Muscle Flaps and Fascia Lata Grafts

    DTIC Science & Technology

    2012-01-01

    muscle, as in a Gil- lies-type temporalis flap for facial reanimation (Figs. 1 and 2). A strip of muscle measuring 5 cm wide is then raised from superior...formed procedure. DISCUSSION The temporalis muscle is a robust flap, and its transfer has long had a place in the history of facial reanimation ...temporalis turndown flaps for dynamic lower lip reanimation in 1934.4 McLaughlin de- scribed disinsertion of the muscle from the coro- noid through a