Science.gov

Sample records for relaxing incision knife

  1. Evaluation of a new disposable silicon limbal relaxing incision knife by experienced users

    PubMed Central

    2009-01-01

    Background Previous research has suggested that the silicon BD Atomic Edge™ knife has superior performance characteristics when compared to a metal knife and performance similar to diamond knife when making various incisions. This study was designed to determine whether a silicon accurate depth knife has equivalent performance characteristics when compared to a diamond limbal relaxing incision (LRI) knife and superior performance characteristics when compared to a steel accurate depth knife when creating limbal relaxing incision. Methods Sixty-five ophthalmic surgeons with limbal relaxing incision experience created limbal relaxing incisions in ex-vivo porcine eyes with silicon and steel accurate depth knives and diamond LRI knives. The ophthalmic surgeons rated multiple performance characteristics of the knives on Visual Analog Scales. Results The observed differences between the silicon knife and diamond knife were found to be insignificant. The mean ratio between the performance of the silicon knife and the diamond knife was shown to be greater than 90% (with 95% confidence). The silicon knife's mean performance was significantly higher than the performance of the steel knife for all characteristics. (p-value < .05) Conclusions For experienced users, the silicon accurate depth knife was found to be equivalent in performance to the diamond LRI knife and superior to the steel accurate depth knife when making limbal relaxing incisions in ex vivo porcine eyes. Disposable silicon LRI knives may be an alternative to diamond LRI knives. PMID:20025762

  2. Characteristics of Bone Injuries Resulting from Knife Wounds Incised with Different Forces.

    PubMed

    Humphrey, Caitlin; Kumaratilake, Jaliya; Henneberg, Maciej

    2017-02-23

    The aim of this research was to experimentally determine the characteristics of incised bone wounds, which are commonly found in defense injuries. A specially constructed pivoting arm device was used to inflict wounds with controlled forces and direction. Five knives were selected to inflict the wounds on porcine forelimbs. Eight incised wounds were made per knife per force. A larger knife and a greater force caused longer and wider bone wounds. Comparisons of individual knives at the two forces produced varying results in the bone wounds. A correlation was seen between the force and the length (r = 0.69), width (r = 0.63), and depth (r = 0.57) of bone wounds. Serrated-edge and nonserrated knives can be distinguished from the appearance of the wound. The outcomes may be applicable in forensic investigations to ascertain the forces associated with incised wounds and identify the specific knife used. © 2017 American Academy of Forensic Sciences.

  3. A case of endophthalmitis associated with limbal relaxing incision.

    PubMed

    Haripriya, Aravind; Syeda, Taranum S

    2012-01-01

    Limbal relaxing incisions (LRIs) are considered a relatively safe procedure with rapid stabilization and absence of infectious complications. Do we need to readdress this last impression? We report a case of nocardia endophthalmitis associated with an exudate at the site of an LRI in a patient who underwent routine cataract surgery. This case, to the best of our knowledge, is the first report of its kind, stressing the need for a cautious approach to the adoption of this method of astigmatic correction.

  4. Relaxing incision for control of postoperative astigmatism following keratoplasty.

    PubMed

    Troutman, R C; Swinger, C

    1980-02-01

    A new technique has been presented which provides a second surgical approach to correct excessive residual astigmatism following keratoplasty. The relaxing incision procedure has advantages over wedge resection in that it can be performed at the slit lamp, it gives no initial overcorrection, and it has a much shorter postoperative course while giving rapid results without suturing. Since this technique does not appear to produce significant hyperopia and may produce a tendency toward myopia, the corneal surgeon would thus have alternative techniques from which to choose, depending, in part, on the spherical component of the refraction.

  5. A case of keratitis associated with limbal relaxing incision.

    PubMed

    Haripriya, Aravind; Smita, Anand

    2016-12-01

    We report a case of keratitis associated with limbal relaxing incision (LRI). The patient presented with progressive loss of vision with best-corrected visual acuity 20/40. Immature cataract with 1.43D against the rule astigmatism was noted. Prophylactic topical antibiotic was administered before surgery. He underwent uneventful phacoemulsification with intraocular lens implantation with LRI. On the 33rd postoperative day (POD), he presented with infiltrate along LRI site with mild iritis. Corneal scraping was positive for Staphylococcus aureus. After the treatment with topical moxifloxacin and fortified cefazolin, the infiltrate started to resolve. On the 50th POD, the corneal infection was resolved with marked thinning at LRI site.

  6. Comparison of wound healing between chopped mode-superpulse mode CO2 laser and steel knife incision.

    PubMed

    Ben-Baruch, G; Fidler, J P; Wessler, T; Bendick, P; Schellhas, H F

    1988-01-01

    The healing of surgical incisions made with the steel knife and CO2 laser chopped wave mode (ChW) or rapid superpulse (RSP) mode were compared using histologic parameters and breaking strength of the scars on postoperative day 14. Using a miniature pig model the Sharplan 1100 laser incisions were made with an average power of 15 W and power density of 7.68 kW/cm2. Histological sections on postoperative day 14 revealed the knife scar measured .49 mm, was hypocellular, and contained visible bundles of collagen fibers. Both CO2 laser scars were less mature, the ChW scar measured 1.04 mm, the RSP scar measured 1.37 mm, and both contained cellular granulation tissue without visible collagen fibers. The breaking strength of the scars was measured with a tensiometer. Laser wounds were weaker than the knife wound. Scheffe test for variables was significant at P = .01 between the two laser modes and the knife. No significant difference was noted in the breaking strengths of incisions made with the chopped mode and superpulse mode.

  7. Efficacy of single-incision needle-knife biopsy for sampling subepithelial lesions

    PubMed Central

    Shimamura, Yuto; Hwang, Jason; Cirocco, Maria; May, Gary R.; Mosko, Jeffrey; Teshima, Christopher W.

    2017-01-01

    Background and study aims Single-incision needle-knife (SINK) biopsy is a diagnostic method for acquiring tissue samples for subepithelial lesions (SELs). A single linear incision is made in the overlying mucosa and tissue samples are obtained by passing conventional biopsy forceps through the opening and deep into the lesion. The aim of this study was to describe the efficacy and safety of this technique. Patients and methods Consecutive patients who underwent SINK biopsy for an upper gastrointestinal SEL between October 2013 and September 2015 were retrospectively reviewed. Results Forty-nine patients underwent 50 SINK biopsies. Sufficient sampling for a definite pathologic diagnosis was obtained in 42 (86 %) cases, with 91 % (40/44) having sufficient sample to perform immunohistochemistry when deemed clinically relevant. Of the 26 patients with prior non-diagnostic biopsies or FNA, a specific diagnosis was obtained in 85 % (22/26). There were no significant adverse events. Conclusions SINK biopsy is a safe and feasible strategy for obtaining a definitive tissue diagnosis with immunohistochemistry for SELs. PMID:28337478

  8. A case of keratitis associated with limbal relaxing incision

    PubMed Central

    Haripriya, Aravind; Smita, Anand

    2016-01-01

    We report a case of keratitis associated with limbal relaxing incision (LRI). The patient presented with progressive loss of vision with best-corrected visual acuity 20/40. Immature cataract with 1.43D against the rule astigmatism was noted. Prophylactic topical antibiotic was administered before surgery. He underwent uneventful phacoemulsification with intraocular lens implantation with LRI. On the 33rd postoperative day (POD), he presented with infiltrate along LRI site with mild iritis. Corneal scraping was positive for Staphylococcus aureus. After the treatment with topical moxifloxacin and fortified cefazolin, the infiltrate started to resolve. On the 50th POD, the corneal infection was resolved with marked thinning at LRI site. PMID:28112139

  9. A stab in the dark: Design and construction of a novel device for conducting incised knife trauma investigations and its initial test.

    PubMed

    Humphrey, Caitlin; Kumaratilake, Jaliya; Henneberg, Maciej

    2016-05-01

    Knife attacks are commonly seen in Australia and other countries. During forensic investigations the force with which a wound was inflicted is often questioned. The ability to examine resultant trauma and particular weapons at different forces with an experimental device may lead to better interpretations of knife wounds. The objective of this study is to design, construct and test a device to analyse the characteristics and forces involved in knife attacks, particularly incised wounds. The mechanical variables (e.g. force, angle, knife geometry) involved in knife attacks have been considered to design and construct a suitable device which allows these variables to be systematically controlled and varied. A device was designed and constructed from mild steel. This included a pivoting arm and instrumented knife holder. The arm has adjustable angle and weight so that knives can be operated at different calculated forces. A device was successfully constructed and the repeatability of incised knife trauma and its characteristics in skeletal tissues were investigated. A device which allows reproducible and controlled experiments with knife wounds will be advantageous to forensic investigations. In particular, in determining forces and types of weapons associated with particular wounds, identifying or eliminating suspected weapons and more accurately answering the common question: How much force would be required to cause that particular wound. This could help to characterise the perpetrator. The device can be altered to be used in the future to investigate trauma caused by other weapons.

  10. Basal lamella relaxing incision improves endoscopic middle meatal access.

    PubMed

    Getz, Anne E; Hwang, Peter H

    2013-03-01

    Lateralization of the middle turbinate is a commonly cited factor leading to failure of functional endoscopic sinus surgery (FESS). Inadequate medialization during FESS may require repeat intraoperative attempts, and may lead to destabilization and mucosal trauma. A novel technique is described that increases middle meatal area and provides more definitive medialization at the outset of FESS. Twenty-nine middle turbinate medializations were prospectively evaluated in 18 consecutive patients undergoing primary ESS. Three intraoperative images of the middle meatus were obtained in the native position, after Freer medialization, and after basal lamella relaxing incision (BLRI). Measurements of middle meatal area were then calculated in a blinded and randomized fashion. Distances measured from the middle turbinate to the lateral nasal wall for each position ranged from 0 to 8 mm (median = 3.00 mm) for the native position, 0.5 to 10 mm (median = 5.00 mm) for standard Freer medialization, and 3 to 21 mm (median = 10.00 mm) for BLRI. Friedman's analysis of variance (ANOVA) showed that there was significant difference between the 3 measurements, and the post hoc Wilcoxon signed ranks tests showed that BLRI distance (median = 10; 95% confidence interval [CI], 7-11.2) was significantly larger than both standard Freer (median = 5; 95% CI, 4-6.2) and native (median = 3; 95% CI, 2-3) and that standard Freer was significantly larger than native (all p values <0.001). BLRI is a safe, controlled technique that provides significantly greater medialization of the middle turbinate compared to standard medialization techniques. BLRI significantly enhances the operative space within the middle meatus. © 2013 ARS-AAOA, LLC.

  11. Basal Lamella Relaxing Incision Improves Endoscopic Middle Meatal Access

    PubMed Central

    Hwang, Peter H.

    2012-01-01

    Background Lateralization of the middle turbinate is a commonly cited factor leading to failure of functional endoscopic sinus surgery (FESS). Inadequate medialization during FESS may require repeat intraoperative attempts, and may lead to destabilization and mucosal trauma. A novel technique is described that increases middle meatal area and provides more definitive medialization at the outset of FESS. Methods Twenty-nine middle turbinate medializations were prospectively evaluated in 18 consecutive patients undergoing primary endoscopic sinus surgery. Three intra-operative images of the middle meatus were obtained in the native position, after Freer medialization, and after basal lamella relaxing incision (BLRI). Measurements of middle meatal area were then calculated in a blinded and randomized fashion. Results Distances measured from the middle turbinate to the lateral nasal wall for each position ranged from 0 to 8 mm (median = 3.00 mm) for the native position, 0.5 to 10 mm (median = 5.00 mm) for Standard Freer medialization, and 3 to 21 mm (median = 10.00 mm) for BLRI. Friedman’s ANOVA showed that there was significant difference between the three measurements, and the post-hoc Wilcoxon signed-ranks tests showed that BLRI distance [median=10, 95% CI (7 to 11.2)] was significantly larger than both Standard Freer [median=5, 95% CI (4 to 6.2)] and Native [median=3, 95% CI (2 to 3)] and that Standard Freer was significantly larger than Native (all p-values <0.001). Conclusions BLRI is a safe, controlled technique that provides significantly greater medialization of the middle turbinate compared to standard medialization techniques. BLRI significantly enhances the operative space within the middle meatus. PMID:23038164

  12. Cyanoacrylate glue treatment for persistent aqueous leak following postkeratoplasty relaxing incisions with compression sutures.

    PubMed

    Karabatsas, C H; Easty, D L

    In spite of improvements in surgical techniques, donor materials and postoperative care, high astigmatism remains a quite common problem following penetrating keratoplasty [1]. Whenever the residual astigmatism cannot be corrected with spectacles or contact lenses, surgical treatment is required. Relaxing incisions combined with compression sutures is one of the most common methods used for this purpose [2, 3]. We report herein a case of persistent aqueous leak following relaxing incisions for the correction of postkeratoplasty astigmatism. The leak failed to respond to a bandage contact lens and resuturing and was eventually successfully treated with the use of cyanoacrylate glue. A marked regression of the surgical effect was observed in this case.

  13. Endoscopy-Assisted Single-Incision Technique to Harvest the Conchal Cartilage and Temporal Fascia Simultaneously by Using Phaco Slit Knife.

    PubMed

    Ugurlu, Alper Mete; Ersozlu, Tolga; Basat, Salih Onur; Ceran, Fatih

    2015-11-01

    Conchal cartilage and temporal fascia grafts are useful materials for secondary rhinoplasty cases. Generally, surgeons require to access autologous grafts fast and effortlessly. Harvesting 2 different types of graft, such as cartilage and fascia, however, are associated with limitations, such as additional surgery time, extra incisions, and postoperative additional distortions at the graft-host interface. The authors evolved a modified single incision that would harvest conchal cartilage and temporal fascia simultaneously by using 4 mm endoscope and 3 mm angled phaco slit knife.

  14. Dosimetric comparison between cone/Iris-based and InCise MLC-based CyberKnife plans for single and multiple brain metastases.

    PubMed

    Jang, Si Young; Lalonde, Ron; Ozhasoglu, Cihat; Burton, Steven; Heron, Dwight; Huq, M Saiful

    2016-09-01

    We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty-four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC- and clinical cone/Iris-based plans. Statistical analysis was performed using the nonparametric Wilcoxon-Mann-Whitney signed-rank test. The planning accuracy of the MLC-based plans was validated using chamber and film measurements. The InCise MLC-based plans achieved mean dose and target coverage comparable to the cone/Iris-based plans. Although the conformity indices of the MLC-based plans were slightly higher than those of the cone/Iris-based plans, beam delivery time for the MLC-based plans was shorter by 30%∼40%. For smaller targets or cases with OARs located close to or abutting target volumes, MLC-based plans provided inferior dose conformity compared to cone/Iris-based plans. The QA results of MLC-based plans were within 5% absolute dose difference with over 90% gamma passing rate using 2%/2 mm gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases. PACS number(s): 87.53.Ly, 87.55.D.

  15. Dosimetric comparison between cone/Iris-based and InCise MLC-based CyberKnife plans for single and multiple brain metastases.

    PubMed

    Jang, Si Young; Lalonde, Ron; Ozhasoglu, Cihat; Burton, Steven; Heron, Dwight; Huq, M Saiful

    2016-09-08

    We performed an evaluation of the CyberKnife InCise MLC by comparing plan qualities for single and multiple brain lesions generated using the first version of InCise MLC, fixed cone, and Iris collimators. We also investigated differences in delivery efficiency among the three collimators. Twenty-four patients with single or multiple brain mets treated previously in our clinic on a CyberKnife M6 using cone/Iris collimators were selected for this study. Treatment plans were generated for all lesions using the InCise MLC. Number of monitor units, delivery time, target coverage, conformity index, and dose falloff were compared between MLC- and clinical cone/Iris-based plans. Statistical analysis was performed using the non-parametric Wilcoxon-Mann-Whitney signed-rank test. The planning accuracy of the MLC-based plans was validated using chamber and film measurements. The InCise MLC-based plans achieved mean dose and target coverage comparable to the cone/Iris-based plans. Although the conformity indices of the MLC-based plans were slightly higher than those of the cone/Iris-based plans, beam delivery time for the MLC-based plans was shorter by 30% ~ 40%. For smaller targets or cases with OARs located close to or abutting target volumes, MLC-based plans provided inferior dose conformity compared to cone/Iris-based plans. The QA results of MLC-based plans were within 5% absolute dose difference with over 90% gamma passing rate using 2%/2 mm gamma criteria. The first version of InCise MLC could be a useful delivery modality, especially for clinical situations for which delivery time is a limiting factor or for multitarget cases.

  16. Corneal graft curvature change after relaxing incisions for post-penetrating keratoplasty astigmatism.

    PubMed

    Feizi, Sepehr; Javadi, Mohammad A

    2012-09-01

    To evaluate change in graft steepness after graft refractive surgery (GRS) consisting of relaxing incisions with or without counterquadrant compression sutures and discover the existing influential factors. In this retrospective study, 78 eyes of 76 patients who had received penetrating keratoplasty for keratoconus underwent GRS because of high post-penetrating keratoplasty astigmatism. Any shift in graft curvature was calculated using the keratometric coupling ratio (CR; the ratio of flattening of the incised meridian to steepening of the opposite meridian). Multiple regression analysis was used to investigate the possible effect of age, graft curvature, number of incisions, use of compression sutures, achieved vector astigmatic correction, and total arc length on CR. Mean patient age was 30.1 ± 10.3 years and mean follow-up period after GRS was 40.1 ± 29.0 months. There was a significant increase in average keratometry from 44.79 ± 2.08 diopters (D) preoperatively to 45.65 ± 1.86 D postoperatively (P < 0.001). Mean keratometric CR was 0.62 ± 1.09. Keratometric CR was significantly associated with patient age (R = 0.53, P = 0.04) and preoperative average keratometry (R = 0.61, P = 0.02). However, keratometric CR failed to show any significant correlation with other variables. A significant increase in graft steepening occurred after GRS, averaging 0.86 D. When both GRS and cataract extraction or phakic intraocular lens implantation are indicated, a staged approach (first GRS followed by phacoemulsification, for example) is advocated to calculate intraocular lens power with accuracy.

  17. Factors Influencing Efficacy of Peripheral Corneal Relaxing Incisions during Cataract Surgery

    PubMed Central

    Hirnschall, Nino; Wiesinger, Jörg; Draschl, Petra; Findl, Oliver

    2015-01-01

    Purpose. To evaluate influencing factors on the residual astigmatism after performing peripheral corneal relaxing incisions (PCRIs) during cataract surgery. Methods. This prospective study included patients who were scheduled for cataract surgery with PCRIs. Optical biometry (IOLMaster 500, Carl Zeiss Meditec AG, Germany) was taken preoperatively, 1 week, 4 months, and 1 year postoperatively. Additionally, corneal topography (Atlas model 9000, Carl Zeiss Meditec AG, Germany), ORA (Ocular Response Analyzer, Reichert Ophthalmic Instruments, USA), and autorefraction (Autorefractometer RM 8800 Topcon) were performed postoperatively. Results. Mean age of the study population (n = 74) was 73.5 years (±9.3; range: 53 to 90) and mean corneal astigmatism preoperatively was −1.82 D (±0.59; 1.00 to 4.50). Mean corneal astigmatism was reduced to 1.14 D (±0.67; 0.11 to 3.89) 4 months postoperatively. A partial least squares regression showed that a high eccentricity of the cornea, a large deviation between keratometry and topography, and a high preoperative astigmatism resulted in a larger postoperative error concerning astigmatism. Conclusions. PCRI causes a reduction of preoperative astigmatism, though the prediction is difficult but several factors were found to be a relevant source of error. PMID:26199739

  18. Comparison of astigmatism correction using either peripheral corneal relaxing incisions or toric intraocular lenses.

    PubMed

    Muftuoglu, Ilkay Kilic; Aydin Akova, Yonca; Aksoy, Sibel; Unsal, Erkan

    2016-01-01

    To compare the efficacy and short-term stability of toric intraocular lenses (tIOL) and peripheral cornea relaxing incisions (PCRI) during phacoemulsification. Patients with preexisting corneal astigmatism had cataract surgery either with tIOL (AcrySof Toric) (39 eyes of 35 patients) or standard intraocular lens (AcrySof) + PCRIs (38 eyes of 33 patients). Patients were retrospectively evaluated for manifest refraction, corneal topography, and uncorrected and corrected visual acuities preoperatively and at postoperative 1 and 6 months. The Alpins vectorial method was used to analyze the target induced astigmatism (TIA) and surgically induced astigmatism (SIA), magnitude of error (the difference between the magnitude of SIA and TIA) (ME), and correction index. Mean preoperative corneal astigmatism was 2.21 ± 1.32 D in the tIOL group and 2.24 ± 0.96 D in the PCRI group; the difference was not significant. The decrease in astigmatism was significant in both groups at last follow-up (64% tIOL group, 32% PCRI group, p<0.01, Wilcoxon signed rank test). The mean remaining refractive astigmatism was significantly higher in the PCRI group than in the tIOL group at 1-month (1.42 ± 1.22, 0.89 ± 0.68, respectively) and 6-month follow-ups (1.75 ± 1.37 D, 0.92 ± 0.72, respectively) (p<0.01). The mean ME was significantly lower (-0.35 versus -0.88) with a higher correction index (0.96 versus 0.56) in the tIOL group at 6 months postoperatively. Both tIOL implantation and using PCRI were effective methods to reduce preoperative astigmatism at the time of the cataract surgery. However, tIOLs provided better remaining astigmatism with a more stable refraction than PCRI.

  19. Diagnostic yield of endoscopic ultrasonography-guided single-incision needle knife biopsy for gastric subepithelial tumors: comparison with resected specimens.

    PubMed

    Kim, Joon Sung; Kim, Byung-Wook; Kim, Gi Jun; Kim, Young Wook; Ryu, Seung Ji; Park, Sung Min; Ji, Jeong-Seon; Jun, Sun Young

    2016-12-01

    Several techniques are recommended for the histologic diagnosis of gastric subepithelial tumors (SETs). The purpose of our study was to evaluate the diagnostic yield and safety of endoscopic ultrasonography-guided single-incision needle knife (SINK) biopsy for the diagnosis of gastric SETs. A retrospective review of patients who received biopsy for gastric SETs from August 2012 to May 2015 was conducted. Patients who received endoscopic ultrasonography and were found to have a SET originating from the muscularis propria of the stomach were included in the study. The aim of our study was to investigate the safety and diagnostic yield of SINK biopsy for gastric SETs. A total of 31 patients received SINK biopsy for SETs. The diagnostic yield of SINK biopsy was 87 % (95 % CI 75-100 %), and the diagnostic accuracy was 89 % (95 % CI 74-105 %). The sensitivity of SINK biopsy to identify gastrointestinal stromal tumors was 83 % (95 % CI 52-98 %); the specificity was 100 % (95 % CI 59-100 %); the positive predictive value was 100 % (95 % CI 69-100 %); and the negative predictive value was 78 % (95 % CI 40-97 %). There were no procedure-related adverse events during and after procedure. The use of SINK biopsy technique in patients with SETs is a good diagnostic tool with high diagnostic yield and accuracy. The method is simple, safe, and associated with few complications.

  20. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy

    PubMed Central

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time. PMID:27217626

  1. Dosimetric and radiobiological comparison of CyberKnife M6™ InCise multileaf collimator over IRIS™ variable collimator in prostate stereotactic body radiation therapy.

    PubMed

    Kathriarachchi, Vindu; Shang, Charles; Evans, Grant; Leventouri, Theodora; Kalantzis, Georgios

    2016-01-01

    The impetus behind our study was to establish a quantitative comparison between the IRIS collimator and the InCise multileaf collimator (MLC) (Accuray Inc. Synnyvale, CA) for prostate stereotactic body radiation therapy (SBRT). Treatment plans for ten prostate cancer patients were performed on MultiPlan™ 5.1.2 treatment planning system utilizing MLC and IRIS for 36.25 Gy in five fractions. To reduce the magnitude of variations between cases, the planning tumor volume (PTV) was defined and outlined for treating prostate gland only, assuming no seminal vesicle or ex-capsule involvement. Evaluation indices of each plan include PTV coverage, conformity index (CI), Paddick's new CI, homogeneity index, and gradient index. Organ at risk (OAR) dose sparing was analyzed by the bladder wall Dmax and V37Gy, rectum Dmax and V36Gy. The radiobiological response was evaluated by tumor control probability and normal tissue complication probability based on equivalent uniform dose. The dose delivery efficiency was evaluated on the basis of planned monitor units (MUs) and the reported treatment time per fraction. Statistical significance was tested using the Wilcoxon signed rank test. The studies indicated that CyberKnife M6™ IRIS and InCise™ MLC produce equivalent SBRT prostate treatment plans in terms of dosimetry, radiobiology, and OAR sparing, except that the MLC plans offer improvement of the dose fall-off gradient by 29% over IRIS. The main advantage of replacing the IRIS collimator with MLC is the improved efficiency, determined from the reduction of MUs by 42%, and a 36% faster delivery time.

  2. Craniosynostosis incision: scalpel or cautery?

    PubMed

    Wood, Jeyhan S; Kittinger, Benjamin J; Perry, Victor L; Adenola, Adeyemi; van Aalst, John A

    2014-07-01

    There is an ongoing debate regarding the optimal instrument for scalp incisions: the scalpel or electrocautery. The argument generally focuses on improved healing after an incision made with a knife and decreased bleeding when using electrocautery. This study compares the use of scalpel and electrocautery in making coronal incisions for patients undergoing surgical correction of craniosynostosis. The outcome metric used is wound healing within 6 months after surgery. All patients presenting to the University of North Carolina Children's Hospital with craniosynostosis between July 1, 2007 and January 1, 2010 requiring a coronal incision for surgical correction were prospectively enrolled. In all of these patients, half of the coronal incision was made with knife; the other half, with needle tip cautery. Side of the incision was specified at the time of surgery in the operative report. Patients were excluded from the study if the instrument for incision was not specified or if only 1 modality was used for the entire incision. Sixty-eight patients underwent cranial vault reconstruction, of which 58 met inclusion criteria. Of the 58 matched pairs, 55 were analyzed statistically. The 3 excluded cases were those who had midline complications. There were 17 wound complications (15%): 8 in the knife group, 6 in the cautery group, and 3 at midline (with indeterminate side for the problem). We found no statistically significant difference in wound healing between incisions made with a knife or with electrocautery.

  3. Using the phacoemulsification crescent knife in dacryocystorhinostomy.

    PubMed

    Fong, K S; Koh, A H; Choo, C T

    1998-04-01

    Dacryocystorhinostomy is an effective treatment for nasolacrimal duct obstruction. Most techniques employ a conventional blade or knife in making the incision of the nasal mucosa and lacrimal sac. The authors describe the use of a phacoemulsification crescent knife for this purpose. This technique can be effective and at the same time safer and easier to perform.

  4. Gamma Knife

    MedlinePlus

    ... equipment? How is safety ensured? What is this equipment used for? The Gamma Knife® and its associated ... in size. top of page How does the equipment work? The Gamma Knife® utilizes a technique called ...

  5. Effect of Relaxing Incisions on the Maxillary Growth after Primary Unilateral Cleft Palate Repair in Mild and Moderate Cases: A Randomized Clinical Trial

    PubMed Central

    Cotrina-Rabanal, Omar; Figallo-Hudtwalcker, Olga; Gonzalez-Vereau, Alicia

    2017-01-01

    Background: The purpose of this study was to evaluate the association between the use of relaxing incisions and maxillary growth disturbance after primary palatoplasty in patients with unilateral cleft lip and palate. Methods: This is a prospective, randomized, double-blind controlled trial study with ethical committee approval between 2 groups of patients with unilateral cleft lip and palate who were operated on using the two-flap and one-flap techniques from 2008 to 2011. Two groups of patients with unilateral cleft lip and palate were operated on using the mentioned techniques by the Outreach Surgical Center Program Lima since 2008. Data collection was accomplished by evaluation of maxillary arch dimensions and dental arch relationships (scored using the 5-year-olds’ index). Results: The mean score for the 5-year-olds’ index was 2.57 for two-flap technique and 2.80 for one-flap technique without statistical significant differences (P = 0.71). Our comparative study did not find statistically significant differences in maxillary arch dimensions between the studied techniques for unilateral cleft palate repair. Good levels of agreement were observed according to the κ statistics. Conclusions: The results arising from this clinical trial do not provide statistical evidence that one technique let us obtain better maxillary development than the other at 5 years. The use of relaxing incisions was not associated with maxillary growth impairment. A technique with limited relaxing incisions does not has better maxillary growth. Additional longer term study is necessary to confirm this preliminary report. PMID:28203502

  6. A Hot Knife Through Ice-Cream: Earthflow Response to Channel Incision (Or Channel Response to Earthflows?), Eel River Canyon, California

    NASA Astrophysics Data System (ADS)

    Mackey, B. H.; Roering, J. J.; McKean, J. A.

    2007-12-01

    Abundant glacier-like earthflow features are recognized as a primary erosional process in the highly erodable Franciscan Melange of the Eel River Basin, CA. Despite their prominence in this "melting ice-cream" topography, many questions regarding their effects on the long term sediment flux from this rapidly eroding basin remain unresolved. For example, does an earthflow's basal shear zone propagate vertically downwards with vertical river incision? What controls the upslope and lateral extent of individual earthflows? How does the erosive power of a river influence the rate of earthflow movement, or conversely do earthflow toe deposits regulate the rate of river incision? Here we present preliminary findings derived from study of 200km2 of lidar data (1m resolution) covering hillslopes adjacent to 30km of the Eel River. Lidar allows detailed analysis of the interaction between earthflows and the drainage network, and we document how inferred changes in local base level are propagated throughout adjacent hillslopes via earthflow movement. The most active earthflows (determined by field surveying and analysis of aerial photos rectified using lidar- generated digital topography) coincide with locally steep sections of channel, while downstream of the most active flows we frequently observe less-active or dormant earthflows. This observation supports the idea that the locations of the most active earthflows coincide with headward propagating knickpoints in the channel. The rate of earthflow movement appears to slow when an earthflow exhausts the upslope area of easily mobilized sediment. Earthflow toes can protrude directly into the channel, causing the channel to narrow and steepen, and even undercut the opposite bank. Large resistant boulders (>2m diameter) transported by the earthflow accumulate in the streambed and appear to both act as a check on further channel incision and earthflow movement. In contrast, areas adjacent to active earthflows exhibit smooth

  7. Peripheral corneal relaxing incisions based on anterior keratometry from Scheimpflug tomography versus Placido topography during standard cataract surgery.

    PubMed

    Nanavaty, Mayank A; Dizon, Marizol; Malde, Shruti; Favor, Danillo; Lake, Damian B

    2016-02-01

    To compare the outcomes of peripheral corneal relaxing incisions (PCRIs) based on standardized nomogram using keratometry from Scheimpflug and Placido machines during standard cataract surgery and to assess the astigmatism neutralization potential of PCRIs. In this prospective, comparative case series of eyes with keratometric astigmatism between 0.75D to 2.5D, undergoing routine cataract surgery, PCRIs were performed using standardized nomogram and keratometric data from either Scheimpflug or Placido machines. A single eye of 42 consecutive patients was recruited in each group. Data on pre- and postoperative uncorrected distance visual acuity (UDVA), corrected DVA (CDVA), keratometry and refraction were assessed at 10 weeks postoperatively. Refractive and keratometric J0 J45 vectors were also analyzed. Data on 41 and 39 eyes were available in each group, respectively. There was a significant reduction in keratometric astigmatism in both groups. However, between Scheimpflug and Placido groups, there was no difference in postoperative logMAR UDVA [0.15 ± 0.18 vs 0.14 ± 0.16, p = 0.82] and CDVA [0.11 ± 0.11 vs 0.09 ± 0.10, p = 0.58], postoperative spherical equivalent [-0.34D ± 0.40D vs -0.50D ± 0.43D, p = 0.11], keratometric J0 [-0.03 ± 0.39 vs 0.01 ± 0.85, p = 0.67] and J45 [-0.03 ± 0.41 vs 0.01 ± 0.86, p = 0.65] and refractive J0 [0.05 ± 0.46 vs -0.03 ± 0.92, p = 0.47)] and J45 [-0.06 ± 0.49 vs -0.03 ± 0.99, p = 0.82] vectors, reduction of keratometric astigmatism [-0.40D ± 0.55D vs -0.35D ± 1.24D, p = 0.75] and the keratometric astigmatism neutralization potential [38.56 % ± 29.71 % vs 52.66 % ± 44.06 %, p = 0.12]. - Although PCRIs performed using Scheimpflug or Placido keratometry reduced the keratometric astigmatism significantly during standard cataract surgery. The astigmatic neutralization potentials of PCRIs comparing these two

  8. Use of Sato's curved laryngoscope and an insulated-tip knife for endoscopic incisional therapy of esophageal web.

    PubMed

    Ohtaka, Masahiko; Kobayashi, Shouji; Yoshida, Takashi; Yamaguchi, Tatsuya; Uetake, Tomoyosi; Sato, Tadashi; Hayashi, Akira; Kanai, Mari; Yamamoto, Takanori; Hatsushika, Kyosuke; Masuyama, Keisuke; Enomoto, Nobuyuki

    2015-05-01

    We experienced two cases of esophageal web accompanying severe stricture that were treated by endoscopic incisions with an insulated-tip knife (IT-knife). With attention paid to the mucosa at the stricture, the lesion was incised with an IT-knife without complications. Sato's curved laryngoscope was used even in cervical esophageal lesions and an excellent field was secured.

  9. Bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes versus cold-knife transurethral incision for the treatment of posterior urethral stricture: a prospective, randomized study

    PubMed Central

    Cai, Wansong; Chen, Zhiyuan; Wen, Liping; Jiang, Xiangxin; Liu, Xiuheng

    2016-01-01

    OBJECTIVE: Evaluate the efficiency and safety of bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes for the treatment of posterior urethral stricture. Compare the outcomes following bipolar plasma vaporization with conventional cold-knife urethrotomy. METHODS: A randomized trial was performed to compare patient outcomes from the bipolar and cold-knife groups. All patients were assessed at 6 and 12 months postoperatively via urethrography and uroflowmetry. At the end of the first postoperative year, ureteroscopy was performed to evaluate the efficacy of the procedure. The mean follow-up time was 13.9 months (range: 12 to 21 months). If re-stenosis was not identified by both urethrography and ureteroscopy, the procedure was considered “successful”. RESULTS: Fifty-three male patients with posterior urethral strictures were selected and randomly divided into two groups: bipolar group (n=27) or cold-knife group (n=26). Patients in the bipolar group experienced a shorter operative time compared to the cold-knife group (23.45±7.64 hours vs 33.45±5.45 hours, respectively). The 12-month postoperative Qmax was faster in the bipolar group than in the cold-knife group (15.54±2.78 ml/sec vs 18.25±2.12 ml/sec, respectively). In the bipolar group, the recurrence-free rate was 81.5% at a mean follow-up time of 13.9 months. In the cold-knife group, the recurrence-free rate was 53.8%. CONCLUSIONS: The application of bipolar plasma-cutting and plasma-loop electrodes for the management of urethral stricture disease is a safe and reliable method that minimizes the morbidity of urethral stricture resection. The advantages include a lower recurrence rate and shorter operative time compared to the cold-knife technique. PMID:26872076

  10. Bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes versus cold-knife transurethral incision for the treatment of posterior urethral stricture: a prospective, randomized study.

    PubMed

    Cai, Wansong; Chen, Zhiyuan; Wen, Liping; Jiang, Xiangxin; Liu, Xiuheng

    2016-01-01

    Evaluate the efficiency and safety of bipolar plasma vaporization using plasma-cutting and plasma-loop electrodes for the treatment of posterior urethral stricture. Compare the outcomes following bipolar plasma vaporization with conventional cold-knife urethrotomy. A randomized trial was performed to compare patient outcomes from the bipolar and cold-knife groups. All patients were assessed at 6 and 12 months postoperatively via urethrography and uroflowmetry. At the end of the first postoperative year, ureteroscopy was performed to evaluate the efficacy of the procedure. The mean follow-up time was 13.9 months (range: 12 to 21 months). If re-stenosis was not identified by both urethrography and ureteroscopy, the procedure was considered "successful". Fifty-three male patients with posterior urethral strictures were selected and randomly divided into two groups: bipolar group (n=27) or cold-knife group (n=26). Patients in the bipolar group experienced a shorter operative time compared to the cold-knife group (23.45±7.64 hours vs 33.45±5.45 hours, respectively). The 12-month postoperative Qmax was faster in the bipolar group than in the cold-knife group (15.54±2.78 ml/sec vs 18.25±2.12 ml/sec, respectively). In the bipolar group, the recurrence-free rate was 81.5% at a mean follow-up time of 13.9 months. In the cold-knife group, the recurrence-free rate was 53.8%. The application of bipolar plasma-cutting and plasma-loop electrodes for the management of urethral stricture disease is a safe and reliable method that minimizes the morbidity of urethral stricture resection. The advantages include a lower recurrence rate and shorter operative time compared to the cold-knife technique.

  11. Comparative evaluation of aspheric toric intraocular lens implantation and limbal relaxing incisions in eyes with cataracts and ≤3 dioptres of astigmatism.

    PubMed

    Lam, Douglas K T; Chow, Vanissa W S; Ye, Cong; Ng, Paul Ka-Fai; Wang, Zheng; Jhanji, Vishal

    2016-02-01

    To compare the visual outcomes of aspheric toric intraocular lens (IOL) implantation and limbal relaxing incisions (LRI) for management of coexisting age-related cataracts and astigmatism. In this prospective study, sixty eyes of 60 patients with visually significant cataract and coexisting corneal astigmatism ≤3 dioptres (D) were randomised to undergo phacoemulsification with either aspheric toric IOL or aspheric monofocal IOL with LRI. The main outcome measures were postoperative 3-month uncorrected visual acuity (UCVA), contrast sensitivity, rotational stability of the toric IOL and spectacle independence. The postoperative UCVA, contrast sensitivity and refractive astigmatism were significantly better than the baseline measurements for both groups (p≤0.001). There was no significant difference detected for these parameters between LRI and toric IOL groups postoperatively (p≥0.119). At both postoperative month 1 and 3, the percentages of eyes in need of spectacles were lower in toric group than LRI group (p≤0.030). IOL misalignment was noted in three eyes in the toric IOL group (mean misalignment 7.67±4.04°). On vector analysis, magnitude of error (ME) was negative in the LRI group indicating undercorrection, whereas the ME was close to zero for toric group. Both toric IOL implantation and LRI were effective in correcting corneal astigmatism ≤3 D during phacoemulsification, while LRI tended to undercorrect astigmatism. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

  12. Comparison of Toric Foldable Iris-Fixated Phakic Intraocular Lens Implantation and Limbal Relaxing Incisions for Moderate-to-High Myopic Astigmatism.

    PubMed

    Lee, Jeihoon; Lee, Hun; Kang, David Sung Yong; Choi, Jin Young; Kim, Eung Kweon; Kim, Tae Im

    2016-11-01

    To compare the effectiveness of toric foldable iris-fixated phakic intraocular lens (pIOL) implantation and non-toric foldable iris-fixated pIOL implantation with limbal relaxing incisions (LRIs) for correcting moderate-to-high astigmatism in myopic eyes. The medical records of 146 patients (195 eyes) with myopic astigmatism who underwent toric foldable iris-fixated pIOL implantation (toric group; 94 eyes) or non-toric foldable iris-fixated pIOL implantation with concurrent LRIs (LRI group; 101 eyes) were retrospectively reviewed. For subgroup analysis, the two groups were subdivided according to preoperative astigmatic severity [moderate, 2.00 to <3.00 diopters (D); high, 3.00-4.00 D]. Visual and astigmatic outcomes were compared 6 months postoperatively. The uncorrected distance visual acuity was at least 20/25 in 100% and 98% of the toric and LRI group eyes, respectively. The toric group had lower mean residual cylindrical error (-0.67±0.39 D vs. -1.14±0.56 D; p<0.001) and greater mean cylindrical error change (2.17±0.56 D vs. 1.63±0.72 D; p<0.001) than the LRI group, regardless of the preoperative astigmatic severity. The mean correction index (1.10±0.16 vs. 0.72±0.24; p<0.001) and success index (0.24±0.14 vs. 0.42±0.21; p<0.001) also differed significantly between the groups. Both surgical techniques considerably reduced astigmatism and had comparable visual outcomes. However, toric foldable iris-fixated pIOL implantation was more reliable for correcting moderate-to-high astigmatism in myopic eyes.

  13. The Shoemaker's Knife

    ERIC Educational Resources Information Center

    Thomson, Ian

    2010-01-01

    Archimedes, the famous Greek mathematician, lived from 287 BCE until approximately 212 BCE. He thought that the figure of two semi-circles on a straight line enclosed by a larger semi-circle resembled a shoemaker's knife. Archimedes called this figure an "arbelos" since arbelos is the Greek word for a shoemaker's knife. The author describes the…

  14. The plasma scalpel: a new thermal knife.

    PubMed

    Glover, J L; Bendick, P J; Link, W J; Plunkett, R J

    1982-01-01

    A new thermal knife, the plasma scalpel, capable of simultaneous division of tissue and coagulation of blood vessels, is described. A high temperature argon gas plasma (unrelated to blood plasma) is created by passing the gas through a direct current arc, ionizing the gas and elevating its temperature to 3000 degrees C. A small plasma cutting jet is formed by a nozzle at the tip of the handpiece. Liver resections and muscle transections performed in a canine model, and full thickness burn excisions in a pig skin model showed effective division of tissue and significantly less blood loss when compared to the steel scalpel. Wound healing studies of histologic comparisons and wound breaking strength were performed for steel, plasma, laser, and electrosurgical scalped incisions in the skin of mice and rats. All thermal knife wounds showed localized tissue damage at the edges of the incision, but the events of healing began at the same time. Compared to the steel scalpel, there was a three to six day delay in the onset of healing, but healing occurred in the normal fashion and all thermal knife wounds reached the same healed breaking strength as the steel scalpel wounds. Clinically, the plasma scalped has been used for 138 procedures in 96 patients. The majority of cases have been transection of muscle, hepatic resection or debridement, or soft tissue debridement. Muscle transection data for the plasma scalped compared to the electrosurgical scalpel has shown virtually no blood loss with a shorter time to hemostasis for the plasma scalpel. The plasma scalpel has proved to be an effective thermal knife, capable of simultaneous division and coagulation. Further development work and proof of its efficacy in the clinical setting are necessary to establish the plasma scalpel and adequately demonstrate its proper role in surgery.

  15. Erbium: YAG Laser Incision of Urethral Structures for Treatment of Urinary Incontinence After Prostate Cancer Spray

    DTIC Science & Technology

    2006-02-01

    devoted to in vivo animal studies comparing the wound healingafter Erbium and Holmium laser incision of the urethra and bladder neck. Further...urinary incontinence. Conventional treatments for stricture (including balloon dilation, cold knife incision, electrocautery, and Holmium laser incision...urethral tissue with a thermal damage zone of only 10-20 µm. This thermal damage zone was much less than that of the Holmium laser which produced 300 µm of

  16. Dynamic gamma knife radiosurgery

    NASA Astrophysics Data System (ADS)

    Luan, Shuang; Swanson, Nathan; Chen, Zhe; Ma, Lijun

    2009-03-01

    Gamma knife has been the treatment of choice for various brain tumors and functional disorders. Current gamma knife radiosurgery is planned in a 'ball-packing' approach and delivered in a 'step-and-shoot' manner, i.e. it aims to 'pack' the different sized spherical high-dose volumes (called 'shots') into a tumor volume. We have developed a dynamic scheme for gamma knife radiosurgery based on the concept of 'dose-painting' to take advantage of the new robotic patient positioning system on the latest Gamma Knife C™ and Perfexion™ units. In our scheme, the spherical high dose volume created by the gamma knife unit will be viewed as a 3D spherical 'paintbrush', and treatment planning reduces to finding the best route of this 'paintbrush' to 'paint' a 3D tumor volume. Under our dose-painting concept, gamma knife radiosurgery becomes dynamic, where the patient moves continuously under the robotic positioning system. We have implemented a fully automatic dynamic gamma knife radiosurgery treatment planning system, where the inverse planning problem is solved as a traveling salesman problem combined with constrained least-square optimizations. We have also carried out experimental studies of dynamic gamma knife radiosurgery and showed the following. (1) Dynamic gamma knife radiosurgery is ideally suited for fully automatic inverse planning, where high quality radiosurgery plans can be obtained in minutes of computation. (2) Dynamic radiosurgery plans are more conformal than step-and-shoot plans and can maintain a steep dose gradient (around 13% per mm) between the target tumor volume and the surrounding critical structures. (3) It is possible to prescribe multiple isodose lines with dynamic gamma knife radiosurgery, so that the treatment can cover the periphery of the target volume while escalating the dose for high tumor burden regions. (4) With dynamic gamma knife radiosurgery, one can obtain a family of plans representing a tradeoff between the delivery time and the

  17. Souvenir knife: a retained transcranial knife blade.

    PubMed

    Davis, Neil L; Kahana, Tzipi; Hiss, Jehuda

    2004-09-01

    Upon necroscopic examination of a homeless male found comatose in the street and pronounced dead at a medical center 12 hours later, a sharp tip of a knife lodged in the right parietal region of his skull was incidentally discovered. The blade transected the diploe and penetrated the cerebral cortex. Subsequent police investigation revealed that this was the remnant of a stabbing attempt on his life several months prior to his death. The cause of death was determined to be unrelated to the metallic blade fragment, thus making it a truly incidental and rare finding of a "souvenir knife." Nevertheless, since the injury sustained in the stabbing was potentially life threatening, the investigation into that assault was reopened.A case report is presented, along with a brief review of the literature on "souvenir objects."

  18. Gamma knife surgery for craniopharyngioma.

    PubMed

    Prasad, D; Steiner, M; Steiner, L

    1995-01-01

    We present our results of Gamma Knife surgery for craniopharyngioma in nine patients. The current status of surgery, radiation therapy, intracavitary instillation of radionucleides and Gamma Knife surgery in the management of craniopharyngiomas is discussed.

  19. Comparative clinical dosimetry with X-knife and gamma knife.

    PubMed

    Semwal, M K; Singh, Sukhvir; Sarin, A; Bhatnagar, S; Pathak, H C

    2012-07-01

    X-knife and gamma knife techniques are well-established for cranial stereotactic radiosurgery (SRS). Due to differences in their radiation delivery methods, some of the dosimetric parameters of these two techniques differ which may have clinical significance. There are many dosimetric studies comparing linear accelerator based techniques such as X-knife with gamma knife but generally from different institutions. We carried out a retrospective comparative study of the dosimetric parameters of the SRS treatments performed at our centre with X-knife (circular cones) and gamma knife. Our results indicate that the dose conformity and dose fall-off in the vicinity of the target volumes were better for patients treated with gamma knife as compared to X-knife. However, the dose fall-off pattern shows a reversal at a larger distance from the target. It was better for the X-knife as compared to gamma knife in the low dose region. Copyright © 2011 Associazione Italiana di Fisica Medica. Published by Elsevier Ltd. All rights reserved.

  20. Pleuroscopic punch biopsy using insulated-tip diathermic knife-2 for the diagnosis of desmoplastic malignant mesothelioma.

    PubMed

    Masai, Kyohei; Sasada, Shinji; Izumo, Takehiro; Taniyama, Tomoko; Nakamura, Yukiko; Chavez, Christine; Sakurai, Hiroyuki; Tsuta, Koji; Tsuchida, Takaaki

    2013-10-01

    Desmoplastic malignant mesothelioma (DMM) is a rare subtype of malignant pleural mesothelioma (MPM) and is often difficult to distinguish from pleural fibrosis and reactive mesothelial hyperplasia, especially if the biopsy samples are small. We performed full-thickness pleural biopsy on a lesion suspected to be DMM using an insulated-tip diathermic knife-2 (IT knife-2) during flex-rigid pleuroscopy. IT knife-2 is a novel electrosurgical device for endoscopic submucosal dissection in the early gastrointestinal cancer. It consists of a needle knife with 3 short blades at the distal end attached to an insulated ceramic tip. A 54-year-old man presenting with chest wall mass and thickened pleura, in whom a computed tomography-guided percutaneous needle aspiration had remained negative, underwent flex-rigid pleuroscopy for definitive diagnosis. While applying electric current, we used the IT knife-2 to incise the pleura in a circular shape just above the endothoracic fascia. The incised pleura was removed by forceps and examined pathologically. The microscopic examination was compatible with DMM. We discovered that pleuroscopic punch biopsy using IT knife-2 can diagnose DMM. Use of IT knife-2 during flex-rigid pleuroscopy can obtain sufficient samples from densely thickened pleura, which is difficult to diagnose with small biopsies.

  1. [CyberKnife radiosurgery--present status and future prospect].

    PubMed

    Nomura, Ryutaro; Suzuki, Ichiro

    2011-03-01

    The CyberKnife Robotic Radiosurgery System is a non-invasive alternative to surgery for the treatment of both cancerous and non-cancerous tumors anywhere in the body, including the prostate, lung, brain, spine, liver, pancreas, and kidney. The treatment, which involves the delivery of high doses of radiation to tumors with extreme accuracy, offers new hope to patients who have inoperable or surgically complex tumors or who may prefer a nonsurgical option. To date, more than 95,000 patients have been treated and more than 207 systems have been installed worldwide. The CyberKnife System is a one-of-a-kind device because of the following reasons. First, the CyberKnife System uses image guidance software to track and continually adjust treatment for any patient or tumor movement. This advantage places the system far ahead of other similar treatments. It allows patients to breathe normally and relax comfortably during treatment. Second, some forms of radiosurgery require rigid head frames that are screwed into the patient's skull in order to minimize any head movement. The CyberKnife System does not require such extreme procedures to maintain the head position; instead, it relies on the sophisticated tracking software, allowing for a much more comfortable and noninvasive treatment. Third, unlike some radiosurgery systems, which can only treat tumors in the head, the CyberKnife System has unlimited reach to treat a broad range of tumors throughout the body, including the prostate, lung, brain, spine, liver, pancreas, and kidney. Finally, the CyberKnife System's treatment accuracy is unrivaled. Its ability to treat tumors with supreme accuracy is noncomparable to that of other radiation therapy and radiosurgery systems. The CyberKnife System can essentially "paint" the tumor with radiation, allowing it to precisely deliver treatment to the tumor alone, sparing surrounding healthy tissue.

  2. A nondeforming rhytidectomy incision.

    PubMed

    Talamas, I

    1999-01-01

    A new incision for facial rhytidectomy is presented that completely avoids deformation of the frame of the hair and allows the hair to be combed back without showing the scar, which becomes almost completely invisible in most patients if the incision is made at exactly the specified level. Several authors have tried to maintain the normal hairline, but some of their incisions deform the frame of the hair on the sides, higher than the level of the outer corner of the eye, and others go even higher than this point outside of the hairline, making the scar quite visible! The indications and contraindications for this operation and its designed incisions are discussed. These incisions encourage plastic surgeons not to remove any scalp in the rhytidectomy, but only the skin, because it is precisely the removal of scalp instead of skin that deforms the face, unless the amount of scalp tissue removed is very small. These same incisions are indicated for men.

  3. Single Incision Laparoscopy for the Management of Postoperative Hemorrhage

    PubMed Central

    Scheib, Stacey

    2012-01-01

    Introduction: Single incision laparoscopic surgery is being used as an access route for an increasing breadth of surgical cases. However, its use to evaluate and manage postoperative hemorrhage after laparoscopic surgery has not been reported. Case Description: A patient with recurrent cervical dysplasia who had undergone 2 previous cold knife conizations underwent a single incision total laparoscopic hysterectomy with right salpingectomy and left salpingo-oophorectomy. On postoperative day 1, she developed signs of intraabdominal hemorrhage. She underwent transcatheter arterial embolization of the left uterine artery and received 3U of packed red blood cells. However, on postoperative day 2, she developed signs of persistent bleeding. Discussion: We discuss our management of this case with single incision laparoscopy. PMID:23318078

  4. The Knife Machine. Module 15.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on the knife machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers one topic: performing special operations on the knife machine (a single needle or multi-needle machine which sews and cuts at the same time). These components are provided: an introduction, directions, an objective,…

  5. The Knife Machine. Module 15.

    ERIC Educational Resources Information Center

    South Carolina State Dept. of Education, Columbia. Office of Vocational Education.

    This module on the knife machine, one in a series dealing with industrial sewing machines, their attachments, and operation, covers one topic: performing special operations on the knife machine (a single needle or multi-needle machine which sews and cuts at the same time). These components are provided: an introduction, directions, an objective,…

  6. A new type of plasma knife and its effect on biological issues--a pilot study.

    PubMed

    Justan, I; Tichý, F; Slavícek, P

    2010-01-01

    Currently, several types of plasma discharge devices have become established for performing surgical procedures or superficial sterilization. Our goal is to introduce a brand new type of plasma discharge device with different characteristics, which we have used for two experiments involving thermal damage to biological tissues. A plasma discharge device with the following characteristics was used for all incisions in plasma group: radio frequency barrier discharger at atmospheric pressure with a working frequency of 13.56 MHz. The working gas was Argon. We used a Cesar 136 generator with typical power 100-150W and with a working gas flow rate between 0.5 and 3 litres per minute. The inner diameter of the end of the nozzle was 0.4mm. A standard Martin electrotome was used for all comparative incisions in the electrotome group. We used two experimental fresh rat cadavers, employing their skin, tails, lungs, livers, kidneys and spleens to make a comparative study between incisions made with a plasma discharge knife and those made with a standard electrotome device. All samples underwent histological verification. Our experiment showed slight differences in the impact on incision edges made by the plasma knife and the electrotome. The most interesting effect is on the skin: the plasma knife does not damage hair bulbs, and it results in less thermal damage. The plasma discharge knife is a promising device for cutting various biological tissues. Its effect can be compared with a standard electrotome, while in some tissues it causes less harm then an electrotome. Moreover, we can adjust its therapeutic effect. However, we do not consider the plasma knife a better choice at present, because maneuvering it is unwieldy.

  7. High grade anorectal stricture complicating Crohn's disease: endoscopic treatment using insulated-tip knife

    PubMed Central

    Chon, Hyung Ku; Shin, Ik Sang; Kim, Sang Wook

    2016-01-01

    Endoscopic treatments have emerged as an alternative to surgery, in the treatment of benign colorectal stricture. Unlike endoscopic balloon dilatation, there is limited data on endoscopic electrocautery incision therapy for benign colorectal stricture, especially with regards to safety and long-term patency. We present a case of a 29-year-old female with Crohn's disease who had difficulty in defecation and passing thin stools. A pelvic magnetic resonance imaging scan, gastrograffin enema, and sigmoidoscopy showed a high-grade anorectal stricture. An endoscopic insulated-tip knife incision was successfully performed to resolve the problem. From our experience, we suggest that endoscopic insulated-tip knife treatment may be a feasible and effective modality for patients with short-segment, very rigid, fibrotic anorectal stricture. PMID:27433152

  8. Endoscopic laser incision of the prostate

    NASA Astrophysics Data System (ADS)

    Gilbert, Peter T. O.

    1998-07-01

    To reduce morbidity and costs of transurethral incision of the prostate in cases with bladder neck obstruction and insignificant prostatic hyperplasia, a Nd:YAG laser, wavelength 1064 nm, was used for endoscopic tissue vaporization. Twenty seven patients suffering from severe urinary obstructive symptoms due to a high-riding vesical neck, were operated on under general anesthesia. Under endoscopic control and by means of a 600 micrometer lateral- firing quartz fiber two incisions were performed, starring at the 7 o'clock and 5 o'clock position, respectively, of the bladder neck and following the floor of the prostatic urethra to either side of the verumontanum. Vaporization was achieved with the fiber in permanent tissue contact and the laser working at 60 W power in continuous mode. Total energy averaged 10,000 J. No catheter was inserted and all patients were discharged on the same day after the first micturition. Anti-inflammatory agents were administered for two weeks. No serious complications were encountered postoperatively. Results were evaluated by means of clinical examination, uroflowmetry, sonographic measurement of residual urine and the International Prostate Symptom Score (IPSS) questionnaire. Considering a mean follow up of 15 months, all patients experienced considerable improvement of their obstruction, their urinary peak flow averaging 21 ml/s and their IPSS score 6.7 (preoperatively 12.2 ml/s and 21.8, respectively). As compared to the Collings knife, laser-incision of the prostate carries no risk of bleeding, thus obviating the need of catheterization. It can safely be done in an outpatient setting, probably as well under local as under general anesthesia.

  9. Alopecia Following Bicoronal Incisions.

    PubMed

    Kadakia, Sameep; Badhey, Arvind; Ashai, Sara; Lee, Thomas S; Ducic, Yadranko

    2017-05-01

    Multiple techniques may be used to perform bicoronal incisions, and alopecia is a known postoperative complication of this procedure. To date, no large studies exist comparing alopecia outcomes among bicoronal incision techniques with and without the use of Raney clips. To determine (1) whether postoperative alopecia is more common when bicoronal incisions are performed with monopolar cautery, Colorado microdissection tip cautery, or traditional cold steel and (2) whether this outcome is affected by the use of Raney clips. This retrospective study of postoperative alopecia included 505 patients undergoing bicoronal incisions in a single head and neck surgery practice from 1997 to 2015 with a minimum follow-up of 1 year. Patients with preexisting baldness as well as patients not following up for the minimum period were excluded. All data analysis took place between 1997 and 2015. Maximum alopecia width was measured in the postoperative period and compared among the technique groups both with and without Raney clip use. Raney clip duration as a product of surgery length was also compared. A total of 505 patients (301 male, 204 female) ranging in age from 3 to 97 years were included in the study (median age, 53.9 years). Of these, 236 underwent bicoronal incisions to approach the skull base, 78 to treat chronic frontal sinusitis unresponsive to endoscopic management or frontal sinus mucocele, 143 for trauma, and 48 for craniofacial surgery. For 173 patients, the cold steel technique was used for both skin and subcutaneous incision, 102 of whom needed Raney clips. For 161 patients, cold steel technique was used for skin incisions and monopolar cautery for subcutaneous incision; 81 of these patients required Raney clips. For 171 patients, Colorado tip microdissection cautery was used for both skin and subcutaneous incision, with Raney clips used in 66 of these patients. Incisions made with cold steel for both skin and subcutaneous tissue, regardless of Raney clip use

  10. The inverted Batman incision: a new incision in transcolumellar incision for open rhinoplasty.

    PubMed

    Nakanishi, Yuji; Nagasao, Tomohisa; Shimizu, Yusuke; Miyamoto, Junpei; Fukuta, Keizo; Kishi, Kazuo

    2013-12-01

    Columellar and nostril shapes often present irregularity after transcolumellar incision for open rhinoplasty, because of the contracture of the incised wound. The present study introduces a new technique to prevent this complication, and verifies its efficacy in improving cosmetic appearance. In our new method, a zig-zag incision with three small triangular flaps is made on the columella and in the pericolumellar regions of the bilateral nostril rims. Since the shape of the incision resembles the contour of an inverted "batman", we term our new method the "Inverted Batman" incision. To verify the effectiveness of the Inverted Batman incision, aesthetic evaluation was conducted for 21 patients operated on using the conventional transcolumellar incision (Conventional Group) and 19 patients operated on using the Inverted Batman incision (Inverted Batman Group). The evaluation was performed by three plastic surgeons, using a four-grade scale to assess three separate items: symmetry of bilateral soft triangles, symmetry of bilateral margins of the columella, and evenness of the columellar surface. The scores of the two groups for these three items were compared using a non-parametric test (Mann-Whitney U-test). With all three items, the Inverted Batman group patients present higher scores than Conventional Group patients. The Inverted Batman incision is effective in preserving the correct anatomical structure of the columella, soft triangle, and nostril rims. Hence, we recommend the Inverted Batman incision as a useful technique for open rhinoplasty.

  11. Biomechanics of knife stab attacks.

    PubMed

    Chadwick, E K; Nicol, A C; Lane, J V; Gray, T G

    1999-10-25

    Equipment, materials and methods for the measurement of the biomechanical parameters governing knife stab attacks have been developed and data have been presented that are relevant to the improvement of standards for the testing of stab-resistant materials. A six-camera Vicon motion analysis system was used to measure velocity, and derive energy and momentum during the approach phase of the attack and a specially developed force-measuring knife was used to measure three-dimensional forces and torque during the impact phase. The body segments associated with the knife were modelled as a series of rigid segments: trunk, upper arm, forearm and hand. The velocities of these segments, together with knowledge of the mass distribution from biomechanical tables, allowed the calculation of the individual segment energy and momentum values. The instrumented knife measured four components of load: axial force (along the length of the blade), cutting force (parallel to the breadth of the blade), lateral force (across the blade) and torque (twisting action) using foil strain gauges. Twenty volunteers were asked to stab a target with near maximal effort. Three styles of stab were used: a short thrust forward, a horizontal style sweep around the body and an overhand stab. These styles were chosen based on reported incidents, providing more realistic data than had previously existed. The 95th percentile values for axial force and energy were 1885 N and 69 J, respectively. The ability of current test methods to reproduce the mechanical parameters measured in human stab attacks has been assessed. It was found that current test methods could reproduce the range of energy and force values measured in the human stab attacks, although the simulation was not accurate in some respects. Non-axial force and torque values were also found to be significant in the human tests, but these are not reproduced in the standard mechanical tests.

  12. Single-incision laparoscopic myomectomy

    PubMed Central

    Jackson, Tiffany R; Einarsson, Jon I

    2011-01-01

    Laparoscopic myomectomy is a minimally invasive surgical option for the treatment of uterine leiomyomas. Single-incision laparoscopy is a relatively new concept that has potential in gynaecological surgery although the technical challenges of single-incision access have limited the widespread use of the technique. The use of intracorporeal suturing is a significant component of the learning curve for laparoscopic myomectomy and presents an even greater challenge with single-incision laparoscopic myomectomy. This article describes a surgeon’s approach to single-incision laparoscopic myomectomy. PMID:21197249

  13. Intralesional Injection of Mitomycin C at Transurethral Incision of Bladder Neck Contracture May Offer Limited Benefit: TURNS Study Group

    PubMed Central

    Redshaw, Jeffrey D.; Broghammer, Joshua A.; Smith, Thomas G.; Voelzke, Bryan B.; Erickson, Bradley A.; McClung, Christopher D.; Elliott, Sean P.; Alsikafi, Nejd F.; Presson, Angela P.; Aberger, Michael E.; Craig, James R.; Brant, William O.; Myers, Jeremy B.

    2015-01-01

    Purpose Injection of mitomycin C may increase the success of transurethral incision of the bladder neck for the treatment of bladder neck contracture. We evaluated the efficacy of mitomycin C injection across multiple institutions. Materials and Methods Data on all patients who underwent transurethral incision of the bladder neck with mitomycin C from 2009 to 2014 were retrospectively reviewed from 6 centers in the TURNS. Patients with at least 3 months of cystoscopic followup were included in the analysis. Results A total of 66 patients underwent transurethral incision of the bladder neck with mitomycin C and 55 meeting the study inclusion criteria were analyzed. Mean ± SD patient age was 64 ± 7.6 years. Dilation or prior transurethral incision of the bladder neck failed in 80% (44 of 55) of patients. Overall 58% (32 of 55) of patients achieved resolution of bladder neck contracture after 1 transurethral incision of the bladder neck with mitomycin C at a median followup of 9.2 months (IQR 11.7). There were 23 patients who had recurrence at a median of 3.7 months (IQR 4.2), 15 who underwent repeat transurethral incision of the bladder neck with mitomycin C and 9 of 15 (60%) who were free of another recurrence at a median of 8.6 months (IQR 8.8), for an overall success rate of 75% (41 of 55). Incision with electrocautery (Collins knife) was predictive of success compared with cold knife incision (63% vs 50%, p=0.03). Four patients experienced serious adverse events related to mitomycin C and 3 needed or are planning cystectomy. Conclusions The efficacy of intralesional injection of mitomycin C at transurethral incision of the bladder neck was lower than previously reported and was associated with a 7% rate of serious adverse events. PMID:25200807

  14. Impact of congenital narrowing of the bulbar urethra (Cobb's collar) and its transurethral incision in children.

    PubMed

    Nonomura, K; Kanno, T; Kakizaki, H; Koyama, T; Yamashita, T; Koyanagi, T

    1999-08-01

    We described the clinical manifestation and outcome after transurethral incision (TUI) of a congenital narrowing of the bulbar urethra (Cobb's collar). Over a period of 11 years a total of 74 boys, from 3 months to 16 years old with a mean age of 5 years, were subjected to TUI. A febrile urinary tract infection (UTI) was the most common symptom in 40 cases, enuresis in 15, urinary incontinence in 11, hematuria in 9, antenatally diagnosed dilated urinary tract in 4 and others in 9. Concurrent bladder instability was detected by cystometry in 27/31 boys older than 3 years with suspicious bladder urgency. When the bulbar narrowing was detected by cystourethroscopy under 8 Fr, the lesion was simultaneously incised by using an infantile resectoscope (Olympus 10 Fr with a knife electrode or Storz 10 F with a cold knife). Vesicoureteral refluxes (VURs) occurred in 39 cases (53%) and it was diminished in 11 and improved in 25 after TUI. Of the 40 cases, 38 (95%) were free from UTI after TUI. For enuresis and urinary incontinence, 14/15 and all 11, respectively, thrived after TUI and the anticholinergic supplement. Although 61 cases were primarily cured with no complications, insufficient cutting and recurrence of the stricture required an additional TUI in 13 cases for whom the knife electrode was mostly used. Overall clinical improvement was obtained in 71/74 (93%) cases after TUI. Meticulous cystourethroscopy is indispensable for detecting a clinically significant bulbar narrowing. TUI of the lesion is useful as a primary treatment in the majority of cases even with concurrent VUR and unstable bladder. A cold knife is preferable to electrocautery in incising this fine anterior urethral lesion.

  15. Heart bypass surgery incision (image)

    MedlinePlus

    ... the left part of the chest between the ribs. This incision is much less traumatic than the traditional heart bypass surgery incision which separates the breast bone. Minimally invasive heart bypass surgery allows the patient less pain and a faster recovery.

  16. Negative dysphotopsia after temporal corneal incisions.

    PubMed

    Cooke, David L

    2010-04-01

    Temporal incisions made during cataract extraction have been purported to cause negative dysphotopsia. A case in which negative dysphotopsia occurred after superior scleral tunnel incisions is described. The dystopsia symptoms resolved immediately after intraocular lens exchange using temporal corneal incisions.

  17. Finite element analysis of neodymium: yttrium-aluminum-garnet incisions for the prevention of anterior capsule contraction syndrome.

    PubMed

    Wang, Yan-ling; Wang, Zhen-ze; Zhao, Lu; Xiong, Shi-hong; Li, Qian; Wang, Ning-li; Sun, An-qiang

    2013-02-01

    Anterior capsular contraction syndrome is a potential complication of continuous curvilinear capsulorhexis (CCC). Three neodymium: yttrium-aluminum-garnet (Nd:YAG) laser relaxing incisions decrease anterior capsular contraction but the mechanism is unknown. The present study analyzed the biomechanical mechanism of three Nd:YAG laser relaxing incisions made to reduce anterior capsular contraction. A three-dimensional control model and a three-dimensional Nd:YAG model of the anterior capsule with an opening diameter of 6 mm were created. Three incisions of 1 mm in length were made centrifugally at intervals of 120° around the opening circle. The stress alterations of the anterior capsule after CCC with and without Nd:YAG relaxation were numerically simulated and compared. In the control model, the stress was axially uniform in the inner area and relatively high near the inner rim of the opening. Meanwhile, in the Nd:YAG model, the stress level was very low in the inner opening areas, especially near the three incisions. The relaxing incisions in the Nd:YAG model significantly released the relatively high stress on the anterior capsule. Additionally, there was a high stress gradient near the relaxing incisions. Biomechanical effects of stress release may be the preventive mechanism of Nd:YAG incision against anterior capsular contraction syndrome.

  18. Reflections on the Knife Edge

    PubMed Central

    Murphy, John Patrick Michael

    2011-01-01

    Introduction The accompanying article, written by John Murphy, a retired lawyer and lifelong outdoorsman from his beloved Colorado Rockies, draws the striking parallel between his experiences as a mountain climber and as a patient with metastatic melanoma facing the hope and uncertainty of experimental therapy. Both are life-threatening circumstances, demanding courage and hope, and challenging our soul in a way almost unique to human experience. Both involve a conscious choice to move forward into dangerous and uncertain territory, and require a determination to look death (John's “Reaper”) in the eye. Many remarkable books and films have been written about such experiences. I recall in particular the 2003 documentary film Touching the Void, about the incredible survival of a mountaineer who returned from a perilous fall in Peru. I highly recommend it to the reader. Another is Laura Hillenbrand's Unbroken: A World War II Story of Survival, Resilience, and Redemption (Random House, 2010), about the survival of a prisoner of war, the celebrated miler Louis Zamperini. Again, unbridled courage and undeniable hope turned futility into future. John Murphy's reflections remind us of the daily heroism of our patients who are holding tight to the lifeline offered by clinical research. Good climbing, John. All of us are with you on that Knife Edge, waiting for our turn to ascend... and hoping to be as courageous as you were then on Capitol Peak and are again now on the Knife Edge of a clinical trial. For our turn will come. PMID:21349953

  19. Maintaining knife sharpness in industrial meat cutting: A matter of knife or meat cutter ability.

    PubMed

    Karltun, J; Vogel, K; Bergstrand, M; Eklund, J

    2016-09-01

    Knife sharpness is imperative in meat cutting. The aim of this study was to compare the impact of knife blade steel quality with meat cutters' individual ability to maintain the cutting edge sharp in an industrial production setting. Twelve meat cutters in two different companies using three different knives during normal production were studied in this quasi-experimental study. Methods included were measuring knife cutting force before and after knife use, time knives were used, ratings of sharpness and discomfort and interviews. Results showed that the meat cutters' skill of maintaining sharpness during work had a much larger effect on knife sharpness during work than the knife steel differences. The ability was also related to feelings of discomfort and to physical exertion. It was found that meat cutters using more knives were more likely to suffer from discomfort in the upper limbs, which is a risk for developing MSD.

  20. CyberKnife radiosurgery for brain metastases.

    PubMed

    Wowra, Berndt; Muacevic, Alexander; Tonn, Jörg-Christian

    2012-01-01

    Classic radiosurgery is a neurosurgical treatment concept for single-fraction irradiation of cerebral lesions not amenable to open surgery. Until recently it has been realized mainly by frame-based technologies (Gamma Knife; stereotactic linear accelerators). The CyberKnife described in 1997 is an image-guided frameless robotic technology for whole-body radiosurgery. It can be used for classic single-fraction radiosurgery and for hypofractionated treatments. The CyberKnife treatment procedure is completely non-invasive and can be repeated throughout the body if necessary. Brain metastases are an important and frequently treated indication of modern radiosurgery. Data concerning radiosurgical treatment of brain metastases with the CyberKnife are reviewed. Scientific evidence shows that the full-body applicability of the CyberKnife is not at the expense of an inferior intracranial treatment quality when compared to standard frame-based technology. The clinical results of CyberKnife single-fraction radiosurgery are in line with the published literature. The attractive therapeutic profile of CyberKnife radiosurgery is reflected by a high tumor control and a low toxicity and the repeatability of the treatments for recurrent metastases. Although hypofractionated treatments (in 3-5 fractions) of brain metastases have been performed with the CyberKnife to treat large metastases, the clinical significance of this new radiosurgical concept is unclear and requires further study. A new approach is to treat the resection cavity with radiosurgery after surgical removal of brain metastases. In this concept radiosurgery replaces fractionated radiation therapy as an adjunct to surgery. The initial results are very promising. The CyberKnife has been established as a modern non-invasive technology for intra- and extracranial radiosurgery. It adds to the oncological armamentarium and confers upon radiosurgery a greater emphasis as an oncological treatment concept.

  1. Peripheral doses in CyberKnife radiosurgery

    SciTech Connect

    Petti, Paula L.; Chuang, Cynthia F.; Smith, Vernon; Larson, David A.

    2006-06-15

    The purpose of this work is to measure the dose outside the treatment field for conformal CyberKnife treatments, to compare the results to those obtained for similar treatments delivered with gamma knife or intensity-modulated radiation therapy (IMRT), and to investigate the sources of peripheral dose in CyberKnife radiosurgery. CyberKnife treatment plans were developed for two hypothetical lesions in an anthropomorphic phantom, one in the thorax and another in the brain, and measurements were made with LiF thermoluminescent dosimeters (TLD-100 capsules) placed within the phantom at various depths and distances from the irradiated volume. For the brain lesion, gamma knife and 6-MV IMRT treatment plans were also developed, and peripheral doses were measured at the same locations as for the CyberKnife plan. The relative contribution to the CyberKnife peripheral dose from inferior- or superior-oblique beams entering or exiting through the body, internally scattered radiation, and leakage radiation was assessed through additional experiments using the single-isocenter option of the CyberKnife treatment-planning program with different size collimators. CyberKnife peripheral doses (in cGy) ranged from 0.16 to 0.041 % ({+-}0.003%) of the delivered number of monitor units (MU) at distances between 18 and 71 cm from the field edge. These values are two to five times larger than those measured for the comparable gamma knife brain treatment, and up to a factor of four times larger those measured in the IMRT experiment. Our results indicate that the CyberKnife peripheral dose is due largely to leakage radiation, however at distances less than 40 cm from the field edge, entrance, or exit dose from inferior- or superior-oblique beams can also contribute significantly. For distances larger than 40 cm from the field edge, the CyberKnife peripheral dose is directly related to the number of MU delivered, since leakage radiation is the dominant component.

  2. Channel incision and water quality

    NASA Astrophysics Data System (ADS)

    Shields, F. D.

    2009-12-01

    Watershed development often triggers channel incision that leads to radical changes in channel morphology. Although morphologic evolution due to channel incision has been documented and modeled by others, ecological effects, particularly water quality effects, are less well understood. Furthermore, environmental regulatory frameworks for streams frequently focus on stream water quality and underemphasize hydrologic and geomorphic issues. Discharge, basic physical parameters, solids, nutrients (nitrogen and phosphorus), chlorophyll and bacteria were monitored for five years at two sites along a stream in a mixed cover watershed characterized by rapid incision of the entire channel network. Concurrent data were collected from two sites on a nearby stream draining a watershed of similar size and cultivation intensity, but without widespread incision. Data sets describing physical aquatic habitat and fish fauna of each stream were available from other studies. The second stream was impacted by watershed urbanization, but was not incised, so normal channel-floodplain interaction maintained a buffer zone of floodplain wetlands between the study reach and the urban development upstream. The incised stream had mean channel depth and width that were 1.8 and 3.5 times as large as for the nonincised stream, and was characterized by flashier hydrology. The median rise rate for the incised stream was 6.4 times as great as for the nonincised stream. Correlation analyses showed that hydrologic perturbations were associated with water quality degradation, and the incised stream had levels of turbidity and solids that were two to three times higher than the nonincised, urbanizing stream. Total phosphorus, total Kjeldahl N, and chlorophyll a concentrations were significantly higher in the incised stream, while nitrate was significantly greater in the nonincised, urbanizing stream (p < 0.02). Physical aquatic habitat and fish populations in the nonincised urbanizing stream were

  3. Single-Incision Laparoscopic Ventral Hernia Repair with Suprapubic Incision

    PubMed Central

    Turingan, Isidro; Tran, Mai

    2013-01-01

    Introduction: Although natural orifice transluminal endoscopic surgery promises truly scarless surgery, this has not progressed beyond the experimental setting and a few clinical cases in the field of ventral hernia repair. This is mainly because of the problem of sterilizing natural orifices, which prevents the use of any prosthetic material because of unacceptable risks of infection. Single-incision laparoscopic ventral hernia repair has gained more widespread acceptance by specialized hernia centers. Even so, there is a special subset of patients who are young and/or scar conscious and find any visible scar unacceptable. This study illustrates an innovative way of performing single-incision laparoscopic ventral hernia repair by a transverse suprapubic incision below the pubic hair/bikini line in 2 young male patients who had both umbilical and epigastric hernias as well as attenuated linea alba in the upper abdomen. Case Description: Both patients underwent successful laparoscopic repair, and both were highly satisfied with the procedure, which produced no visible scars on their abdomen. Discussion: Willingness to adopt new innovative procedures, such as single-incision laparoscopic surgery, has allowed modification of the incision site to produce invisible scars and hence become highly attractive to the young and scar-phobic segment of the population. PMID:23925028

  4. Transluminal endoscopic electrosurgical incision of fenestrated duodenal membranes.

    PubMed

    Blanco-Rodríguez, Gerardo; Penchyna-Grub, Jaime; Porras-Hernández, Juan D; Trujillo-Ponce, Adrián

    2008-06-01

    Duodenal fenestrated membranes are traditionally treated by side-to-side diamond-shaped duodenoduodenostomy, or duodenotomy and resection. We describe an alternative endoscopic approach for its resolution. A flexible panendoscopy reaching the duodenal membrane was performed. A balloon was inserted to dilate its orifice. Traction was applied to the balloon to differentiate the border of the membrane forming the duodenal wall. After visualizing the ampulla, the membrane was incised using a sphincterotome or needle knife on two sites opposite to the bile duct. From May 2001 to August 2007, ten patients with a fenestrated duodenal membrane underwent transluminal endoscopic electrosurgical incision (TEEI). Mean patient age was 3.4 years (range 1 month to 15 years). The endoscopic procedure lasted from 30 to 60 min. Oral intake began 24 h postsurgery in eight patients and at 48 h postsurgery in two patients. Hospital stay lasted for 2-5 days. After 1 year of follow-up, eight patients were asymptomatic and thriving at present, and one had a double membrane, required a second endoscopy with TEEI, and has experienced occasional vomiting. An additional asymptomatic patient was lost after 3 months of follow-up. TEEI of fenestrated duodenal membranes is a feasible and effective procedure in children.

  5. Knife-edge seal for vacuum bagging

    NASA Technical Reports Server (NTRS)

    Rauschl, J. A.

    1980-01-01

    Cam actuated clamps pinch bagging material between long knife edge (mounted to clamps) and high temperature rubber cushion bonded to baseplate. No adhesive, tape, or sealing groove is needed to seal edge of bagging sheet against base plate.

  6. A sharp knife for high temperatures

    NASA Technical Reports Server (NTRS)

    Heisman, R. M.; Iceland, W. F.

    1978-01-01

    Electrically heated nickel-chrome-steel alloy knife may be used to cut heat resistant plastic felt and similar materials with relative ease. Blade made of commercially available alloy RA 330 retains edge at temperatures as high as 927 C.

  7. Gamma Knife Radiosurgery for Acromegaly

    PubMed Central

    Rolston, John D.; Blevins, Lewis S.

    2012-01-01

    Acromegaly is debilitating disease occasionally refractory to surgical and medical treatment. Stereotactic radiosurgery, and in particular Gamma Knife surgery (GKS), has proven to be an effective noninvasive adjunct to traditional treatments, leading to disease remission in a substantial proportion of patients. Such remission holds the promise of eliminating the need for expensive medications, along with side effects, as well as sparing patients the damaging sequelae of uncontrolled acromegaly. Numerous studies of radiosurgical treatments for acromegaly have been carried out. These illustrate an overall remission rate over 40%. Morbidity from radiosurgery is infrequent but can include cranial nerve palsies and hypopituitarism. Overall, stereotactic radiosurgery is a promising therapy for patients with acromegaly and deserves further study to refine its role in the treatment of affected patients. PMID:22518132

  8. Small-incision lenticule extraction.

    PubMed

    Moshirfar, Majid; McCaughey, Michael V; Reinstein, Dan Z; Shah, Rupal; Santiago-Caban, Luis; Fenzl, Carlton R

    2015-03-01

    This review looks at the benefits, limitations, complications, and future applications of the small-incision lenticule extraction procedure. Using the search terms small incision lenticule extraction and femtosecond lenticule extraction, we obtained data from 56 articles (omitting German and Chinese articles) from the PubMed database. Small-incision lenticule extraction has shown efficacy, predictability, and safety that are proportionate to those of laser in situ keratomileusis (LASIK), with the additional benefit that it eliminates flap creation and the attendant risks. The potential advantages of the procedure related to improved biomechanical stability, postoperative inflammation, and dry-eye symptoms have not been fully established. Small-incision lenticule extraction-treated eyes have shown a reduced degree of postoperative corneal denervation and higher-order aberrations and an accelerated rate of corneal nerve convalescence relative to LASIK. Future possibilities related to long-term cryogenic storage of extracted lenticules with eventual reimplantation or donation have been investigated with encouraging preliminary results. Drs. Reinstein and Shah are consultants to Carl Zeiss Meditec AG. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2015 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  9. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  10. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  11. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  12. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  13. 21 CFR 886.4230 - Ophthalmic knife test drum.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Ophthalmic knife test drum. 886.4230 Section 886...) MEDICAL DEVICES OPHTHALMIC DEVICES Surgical Devices § 886.4230 Ophthalmic knife test drum. (a) Identification. An ophthalmic knife test drum is a device intended to test the keenness of ophthalmic...

  14. Relaxed heaps

    SciTech Connect

    Driscoll, J.R. ); Gabow, H.N.; Shrairman, R. ); Tarjan, R.E. )

    1988-11-01

    The relaxed heap is a priority queue data structure that achieves the same amortized time bounds as the Fibonacci heap - a sequence of m decrease key and n delete min operations takes time O(m + n log n). A variant of relaxed heaps achieves similar bounds in the worst case - O(1) time for decrease key and O(log n) for delete min. Relaxed heaps give a processor-efficient parallel implementation of Dijkstra's shortest path algorithm, and hence other algorithms in network optimization. A relaxed heap is a type of binomial queue that allows heap order to be violated.

  15. Single-step, natural orifice transluminal endoscopic incision drainage of a pancreatic pseudocyst: can it be simpler, safer and more cost effective?

    PubMed

    Hyder, Qurratulain; Zahid, Mohammad Ahmad; Malik, Arif; Rasheed, Rakhshanda

    2011-11-01

    Conventional endotherapy for pancreatic pseudocyst involves placement of stents in the cyst cavity. We have successfully treated bulging pseudocyst in a 50 year old male by endoscopic incision drainage (EID), without insertion of endoprostheses. The presenting complaints in our patient were epigastric mass and postprandial vomiting. He had recently undergone open cholecystectomy following recovery from gallstone pancreatitis. EID was performed under general anaesthesia. Needle knife was advanced through the accessory channel of a flexible gastroscope. Cyst contents were evacuated by making 5 cm horizontal incision on the gastric indentation with dramatic relief in symptoms There is no cyst recurrence during follow up for over 3 years.

  16. SMART micro-scissors based precise incision

    NASA Astrophysics Data System (ADS)

    Park, Hyun-Cheol; Yeo, Chaebeom; Song, Cheol

    2015-03-01

    Hand tremor reduction is important to achieve stable micro manipulation of the tool tip. A micro-scissors can be used for cutting delicate tissues safely. Here, we implement an OCT distance sensor guided SMART micro-scissors which could incise micro-surgical targets precisely and horizontally. Compared to freehand incision, it demonstrates enhanced incision performance on dry phantoms with great tremor suppression.

  17. Impalement head injury with serrated meat knife.

    PubMed

    Binitie, Op; Shilong, Dj; Ugwu, Bt; Ekedigwe, Je; Oyeniran, Oo; Adighije, Pf; Mairiga, An; Ninmol, Pj; Alayande, B

    2012-01-01

    An unsuspecting motorcycle passenger was ambushed and impaled on the right side of the head with a 30cm serrated meat carving knife during a sectarian crisis in the city of Jos, Plateau State, Nigeria. The patient escaped running with the knife in his head and was rescued to a military hospital from where he was promptly transferred within 90 minutes of the incident to the Emergency Department of Jos University Teaching Hospital (JUTH), Jos. Prompt resuscitation and CT brain imaging facilitated a successful neurosurgical intervention and a good outcome in the management of this patient.

  18. Automated Gamma Knife dose planning

    NASA Astrophysics Data System (ADS)

    Leichtman, Gregg S.; Aita, Anthony L.; Goldman, H. W.

    1998-06-01

    The Gamma Knife (Elekta Instruments, Inc., Atlanta, GA), a neurosurgical, highly focused radiation delivery device, is used to eradicate deep-seated anomalous tissue within the human brain by delivering a lethal dose of radiation to target tissue. This dose is the accumulated result of delivering sequential `shots' of radiation to the target where each shot is approximately 3D Gaussian in shape. The size and intensity of each shot can be adjusted by varying the time of radiation exposure and by using one of four collimator sizes ranging from 4 - 18 mm. Current dose planning requires that the dose plan be developed manually to cover the target, and only the target, with a desired minimum radiation intensity using a minimum number of shots. This is a laborious and subjective process which typically leads to suboptimal conformal target coverage by the dose. We have used adaptive simulated annealing/quenching followed by Nelder-Mead simplex optimization to automate the selection and placement of Gaussian-based `shots' to form a simulated dose plane. In order to make the computation of the problem tractable, the algorithm, based upon contouring and polygon clipping, takes a 2 1/2-D approach to defining the cost function. Several experiments have been performed where the optimizers have been given the freedom to vary the number of shots and the weight, collimator size, and 3D location of each shot. To data best results have been obtained by forcing the optimizers to use a fixed number of unweighted shots with each optimizer set free to vary the 3D location and collimator size of each shot. Our preliminary results indicate that this technology will radically decrease planning time while significantly increasing accuracy of conformal target coverage and reproducibility over current manual methods.

  19. SIMPLIFIED LAPAROSCOPIC CHOLECYSTECTOMY WITH TWO INCISIONS

    PubMed Central

    ABAID, Rafael Antoniazzi; CECCONELLO, Ivan; ZILBERSTEIN, Bruno

    2014-01-01

    Background Laparoscopic cholecystectomy has traditionally been performed with four incisions to insert four trocars, in a simple, efficient and safe way. Aim To describe a simplified technique of laparoscopic cholecystectomy with two incisions, using basic conventional instrumental. Technique In one incision in the umbilicus are applied two trocars and in epigastrium one more. The use of two trocars on the same incision, working in "x" does not hinder the procedure and does not require special instruments. Conclusion Simplified laparoscopic cholecystectomy with two incisions is feasible and easy to perform, allowing to operate with ergonomy and safety, with good cosmetic result. PMID:25004296

  20. Needle knife papillotomy in a university referral practice. Safety and efficacy of a modified technique.

    PubMed

    Gholson, C F; Favrot, D

    1996-10-01

    To study the utility of needle knife papillotomy (NKP), we retrospectively reviewed 575 consecutive endoscopic retrograde cholangiopancreatography (ERCP) procedures performed over a 3.5-year period. Seventy patients (12.2%) underwent NKP utilizing a shallow ampullary mucosal incision followed by probing with a taper-tipped cannula. Usually a prelude to anticipated therapeutic intervention, NKP was also performed purely for diagnosis in 15 patients (21.4%). The incised ampulla was normal-sized in the majority (53 of 70, 75.7%), and ductal dilatation was present in 49 of 70 cases (70%). NKP was performed de novo in 63 patients, one of whom had Billroth II anatomy, and stent-guided NKP was performed in seven patients (10%), two of whom had Billroth II anatomy. Biliary access was immediate in 68 patients (97.1%) and successful 24 h later in two cases. The NKP incision was completed with a traction sphincterotome in 45 patients (64.3%). Complications occurred after NKP in five patients (7.1%), compared with 11 complications (4.2%) among a concurrent 261 patients who underwent standard ES without NKP. All complications following NKP were selflimited, including pancreatitis (n = 2) and bleeding (n = 2). Our experience indicates that NKP is versatile, effective, and safe with broad applicability in an academic referral practice.

  1. Submillisecond Optical Knife-Edge Testing

    NASA Technical Reports Server (NTRS)

    Thurlow, P.

    1983-01-01

    Fast computer-controlled sampling of optical knife-edge response (KER) signal increases accuracy of optical system aberration measurement. Submicrosecond-response detectors in optical focal plane convert optical signals to electrical signals converted to digital data, sampled and feed into computer for storage and subsequent analysis. Optical data are virtually free of effects of index-of-refraction gradients.

  2. Concomitant GRID boost for Gamma Knife radiosurgery

    SciTech Connect

    Ma Lijun; Kwok, Young; Chin, Lawrence S.; Simard, J. Marc; Regine, William F.

    2005-11-15

    We developed an integrated GRID boost technique for Gamma Knife radiosurgery. The technique generates an array of high dose spots within the target volume via a grid of 4-mm shots. These high dose areas were placed over a conventional Gamma Knife plan where a peripheral dose covers the full target volume. The beam weights of the 4-mm shots were optimized iteratively to maximize the integral dose inside the target volume. To investigate the target volume coverage and the dose to the adjacent normal brain tissue for the technique, we compared the GRID boosted treatment plans with conventional Gamma Knife treatment plans using physical and biological indices such as dose-volume histogram (DVH), DVH-derived indices, equivalent uniform dose (EUD), tumor control probabilities (TCP), and normal tissue complication probabilities (NTCP). We found significant increase in the target volume indices such as mean dose (5%-34%; average 14%), TCP (4%-45%; average 21%), and EUD (2%-22%; average 11%) for the GRID boost technique. No significant change in the peripheral dose coverage for the target volume was found per RTOG protocol. In addition, the EUD and the NTCP for the normal brain adjacent to the target (i.e., the near region) were decreased for the GRID boost technique. In conclusion, we demonstrated a new technique for Gamma Knife radiosurgery that can escalate the dose to the target while sparing the adjacent normal brain tissue.

  3. Climatic control of bedrock river incision.

    PubMed

    Ferrier, Ken L; Huppert, Kimberly L; Perron, J Taylor

    2013-04-11

    Bedrock river incision drives the development of much of Earth's surface topography, and thereby shapes the structure of mountain belts and modulates Earth's habitability through its effects on soil erosion, nutrient fluxes and global climate. Although it has long been expected that river incision rates should depend strongly on precipitation rates, quantifying the effects of precipitation rates on bedrock river incision rates has proved difficult, partly because river incision rates are difficult to measure and partly because non-climatic factors can obscure climatic effects at sites where river incision rates have been measured. Here we present measurements of river incision rates across one of Earth's steepest rainfall gradients, which show that precipitation rates do indeed influence long-term bedrock river incision rates. We apply a widely used empirical law for bedrock river incision to a series of rivers on the Hawaiian island of Kaua'i, where mean annual precipitation ranges from 0.5 metres to 9.5 metres (ref. 12)-over 70 per cent of the global range-and river incision rates averaged over millions of years can be inferred from the depth of river canyons and the age of the volcanic bedrock. Both a time-averaged analysis and numerical modelling of transient river incision reveal that the long-term efficiency of bedrock river incision across Kaua'i is positively correlated with upstream-averaged mean annual precipitation rates. We provide theoretical context for this result by demonstrating that our measurements are consistent with a linear dependence of river incision rates on stream power, the rate of energy expenditure by the flow on the riverbed. These observations provide rare empirical evidence for the long-proposed coupling between climate and river incision, suggesting that previously proposed feedbacks among topography, climate and tectonics may occur.

  4. Limited incision carpal tunnel release

    PubMed Central

    Gaba, Sunil; Bhogesha, Sandeep; Singh, Onkar

    2017-01-01

    Background: Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Limited incision techniques for carpal tunnel release are gaining popularity. The main advantages of these techniques are less scar load, less pillar pain, shorter recovery, and return-to-work time. However, the completeness of release, and risk of neurovascular injury are always a concern. We devised a method of limited incision release with two mini-incisions and use of nasal speculum and a probe. We aimed to evaluate the clinical and neurological outcome of this technique. Materials and Methods: Twenty seven cases (9 male and 18 female, age 28–56 years) of isolated CTS cases were enrolled in the study. A total of 33 hands (six bilateral) underwent limited incision carpal tunnel release. In this study, two mini-incisions were used and release was done with the help of nasal speculum. Evaluation preoperatively and in 6 months and at 1-year postoperatively was done, namely, (a) clinical status examination, (b) motor testing using grip and pinch dynamometer, and (c) neurological outcome measure using nerve conduction study. Results: All the patients had good clinical and neurological outcome with no recurrence during followup. The first symptom to get relieved was night pains, with a mean of 4.5 days (range 2–14 days). Compared to pain, improvement of sensory symptoms was delayed; the mean duration was 42.8 days (range 30–90 days). Scar tenderness was present only for a mean duration of 9 days (range 7–21 days). The mean duration for patients to resume their daily activities was12 days (range 7–28 days) and to work was 32 days (range 21–90 days). The hand grip showed mean values of 45.12 ± 16.16 g/mm2 preoperatively, 62.45 ± 18.86 g/mm2 at 6 months postoperatively, and 74.87 ± 20.35 g/mm2 at 1-year postoperatively. The key pinch showed mean values of 11.27 ± 3.51 g/mm2 preoperatively, 20.181 ± 3.94 g/mm2 at 6 months postoperatively, and 27.96 ± 94.42 g/mm2

  5. Limited incision carpal tunnel release.

    PubMed

    Gaba, Sunil; Bhogesha, Sandeep; Singh, Onkar

    2017-01-01

    Carpal tunnel syndrome (CTS) is the most common peripheral entrapment neuropathy. Limited incision techniques for carpal tunnel release are gaining popularity. The main advantages of these techniques are less scar load, less pillar pain, shorter recovery, and return-to-work time. However, the completeness of release, and risk of neurovascular injury are always a concern. We devised a method of limited incision release with two mini-incisions and use of nasal speculum and a probe. We aimed to evaluate the clinical and neurological outcome of this technique. Twenty seven cases (9 male and 18 female, age 28-56 years) of isolated CTS cases were enrolled in the study. A total of 33 hands (six bilateral) underwent limited incision carpal tunnel release. In this study, two mini-incisions were used and release was done with the help of nasal speculum. Evaluation preoperatively and in 6 months and at 1-year postoperatively was done, namely, (a) clinical status examination, (b) motor testing using grip and pinch dynamometer, and (c) neurological outcome measure using nerve conduction study. All the patients had good clinical and neurological outcome with no recurrence during followup. The first symptom to get relieved was night pains, with a mean of 4.5 days (range 2-14 days). Compared to pain, improvement of sensory symptoms was delayed; the mean duration was 42.8 days (range 30-90 days). Scar tenderness was present only for a mean duration of 9 days (range 7-21 days). The mean duration for patients to resume their daily activities was12 days (range 7-28 days) and to work was 32 days (range 21-90 days). The hand grip showed mean values of 45.12 ± 16.16 g/mm(2) preoperatively, 62.45 ± 18.86 g/mm(2) at 6 months postoperatively, and 74.87 ± 20.35 g/mm(2) at 1-year postoperatively. The key pinch showed mean values of 11.27 ± 3.51 g/mm(2) preoperatively, 20.181 ± 3.94 g/mm(2) at 6 months postoperatively, and 27.96 ± 94.42 g/mm(2) at 1-year postoperatively. The tip pinch

  6. Minimal Incision Congenital Cardiac Surgery

    PubMed Central

    del Nido, Pedro J.

    2008-01-01

    Minimally invasive techniques have had limited application in congenital cardiac surgery, primarily due to the complexity of the defects, small working area, and the fact that most defects require exposure to intracardiac structures. Advances in cannula design and instrumentation have allowed application of minimal incision techniques but in most cases, cardiopulmonary bypass is still required. Image guided surgery, which uses non-invasive imaging to guide intracardiac procedures, holds the promise of permitting performance of reconstructive surgery in the beating heart in children. PMID:18395631

  7. Usefulness and safety of SB knife Jr in endoscopic submucosal dissection for colorectal tumors.

    PubMed

    Oka, Shiro; Tanaka, Shinji; Takata, Sayaka; Kanao, Hiroyuki; Chayama, Kazuaki

    2012-05-01

    Use of a Dual knife has become commonplace for endoscopic submucosal dissection (ESD) of colorectal tumors at Hiroshima University Hosipital. A Hook knife has been also used in combination with the Dual knife, depending on the location of the lesion. We have had recent opportunities to use a scissors-type SB knife Jr. We retrospectively compared outcomes of colorectal ESD performed with the Dual knife in combination with the SB knife Jr versus the Hook knife. In conclusion, although the Hook knife was shown to be a very useful auxiliary device for colorectal ESD, the SB knife Jr. yielded better results than the Hook knife in terms of complete en block resection and avoidance of perforation. Use of the Dual knife with the SB Knife Jr shows good potential for improving complete en bloc resection rate and safety of technically difficult colorectal ESD.

  8. Single-incision total laparoscopic hysterectomy.

    PubMed

    Sinha, Rakesh; Sundaram, Meenakshi; Mahajan, Chaitali; Raje, Shweta; Kadam, Pratima; Rao, Gayatri; Shitut, Prachi

    2011-01-01

    Single-incision laparoscopic surgery is an alternative to conventional multiport laparoscopy. Single-access laparoscopy using a transumbilical port affords maximum cosmetic benefits because the surgical incision is hidden in the umbilicus. The advantages of single-access laparoscopic surgery may include less bleeding, infection, and hernia formation and better cosmetic outcome and less pain. The disadvantages and limitations include longer surgery time, difficulty in learning the technique, and the need for specialized instruments. Ongoing refinement of the surgical technique and instrumentation is likely to expand its role in gynecologic surgery in the future. We perform single-incision total laparoscopic hysterectomy using three ports in the single transumbilical incision.

  9. Single-incision total laparoscopic hysterectomy

    PubMed Central

    Sinha, Rakesh; Sundaram, Meenakshi; Mahajan, Chaitali; Raje, Shweta; Kadam, Pratima; Rao, Gayatri; Shitut, Prachi

    2011-01-01

    Single-incision laparoscopic surgery is an alternative to conventional multiport laparoscopy. Single-access laparoscopy using a transumbilical port affords maximum cosmetic benefits because the surgical incision is hidden in the umbilicus. The advantages of single-access laparoscopic surgery may include less bleeding, infection, and hernia formation and better cosmetic outcome and less pain. The disadvantages and limitations include longer surgery time, difficulty in learning the technique, and the need for specialized instruments. Ongoing refinement of the surgical technique and instrumentation is likely to expand its role in gynecologic surgery in the future. We perform single-incision total laparoscopic hysterectomy using three ports in the single transumbilical incision. PMID:21197248

  10. History and present status of gamma knife radiosurgery in Japan.

    PubMed

    Otto, Stephen

    2009-01-01

    The Leksell GammaKnife has been received well by the medical community since its introduction at Tokyo University Hospital in late 1989. Knowledgeable users, working with the Elekta Company and with foreign GammaKnife users, have contributed to this success. The original indications have grown as Japanese users--again along with their foreign compatriots--found new ways to combat intracranial diseases using the GammaKnife.

  11. Relaxation System

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Environ Corporation's relaxation system is built around a body lounge, a kind of super easy chair that incorporates sensory devices. Computer controlled enclosure provides filtered ionized air to create a feeling of invigoration, enhanced by mood changing aromas. Occupant is also surrounded by multidimensional audio and the lighting is programmed to change colors, patterns, and intensity periodically. These and other sensory stimulators are designed to provide an environment in which the learning process is stimulated, because research has proven that while an individual is in a deep state of relaxation, the mind is more receptive to new information.

  12. Some observations on glass-knife making.

    PubMed

    Ward, R T

    1977-11-01

    The yield of usable knife edge per knife (for thin sectioning) was markedly increased when glass knives were made at an included angle of 55 degrees rather than the customary 45 degrees. A large number of measurements of edge check marks made with a routine light scattering method as well as observations made on a smaller number of test sections with the electron microscope indicated the superiority of 55 degrees knives. Knives were made with both taped pliers and an LKB Knifemaker. Knives were graded by methods easily applied in any biological electron microscope laboratory. Depending on the mode of fracture, the yield of knives having more than 33% of their edges free of check marks was 30 to 100 times greater at 55 degrees than 45 degrees.

  13. Knife blade as a facial foreign body.

    PubMed

    Gardner, P A; Righi, P; Shahbahrami, P B

    1997-08-01

    This case demonstrates the unpredictability of foreign bodies in the face. The retained knife blade eluded detection on two separate examinations. The essential components to making a correct diagnosis of a foreign body following a stabbing to the face include a thorough review of the mechanism of injury, a complete head and neck examination, a high index of suspicion, and plain radiographs of the face.

  14. Comparison of modified Cherney incision and vertical midline incision for management of early stage cervical cancer.

    PubMed

    Lee, San Hui; Yim, Ga Won; Lee, Dae Woo; Kim, Sang Wun; Kim, Sunghoon; Kim, Jae Wook; Kim, Young Tae

    2008-12-01

    The aim of this study was to compare operative feasibility and surgical outcome of the modified Cherney incision and vertical midline incision in patients undergoing radical hysterectomy and pelvic lymphadenectomy. Between March 2005 and December 2007, retrospective data of 78 patients (n=17; modified Cherney incision, n=61; vertical midline incision) with early stage cervical cancer who received radical hysterectomy and pelvic lymphadenectomy were reviewed. Baseline characteristics of patients who underwent modified Cherney incision and vertical midline incision were similar except for age (mean+/-SD: 32.3+/-3.4 yr vs. 52.5+/-8.4 yr, p<0.001). Patients who received modified Cherney incision had earlier initiation of soft diet (mean+/-SD: 46.5+/-19.5 hr vs. 56.4+/-25.4 hr, p<0.016) and shorter hospital stay compared to those who received vertical midline incision (mean+/-SD: 18.0+/-4.8 days vs. 21.7+/-3.7 days, p<0.042). There was no difference in the number of dissected pelvic lymph nodes, hemoglobin change, postoperative pain, postoperative ileus, Foley indwelling duration, and perioperative complications. Excluding the selection bias for age, there was no significant difference of the clinical outcome between the modified Cherney incision group and the vertical midline incision group. Modified Cherney incision can be cosmetically performed in young age women obtaining equal number of lymph nodes without increased operative morbidity compared to vertical midline incision.

  15. Gamma Knife Radiosurgery for Choroidal Hemangioma

    SciTech Connect

    Kim, Yun Taek; Kang, Se Woong; Lee, Jung-Il

    2011-12-01

    Purpose: Patients with choroidal hemangioma (CH), a benign ocular hamartoma, frequently presents with visual disturbance as a result of exudative retinal detachment (RD), which originates in subretinal fluid accumulation. We report our experience using the Leksell Gamma Knife in the management of symptomatic CH. Methods and Materials: Seven patients with symptomatic CH (circumscribed form in 3 patients and diffuse form in 4) were treated with the Leksell Gamma Knife at our institution during a 7-year period. All patients presented with exudative RD involving the macula that resulted in severe visual deterioration. The prescription dose to the target margin was 10 Gy in all cases. The mean tumor volume receiving the prescription dose was 536 mm{sup 3} (range, 151-1,057). The clinical data were analyzed in a retrospective fashion after a mean follow-up of 34.4 months (range, 9-76). Results: The resolution of exudative RD was achieved within 6 months, and the visual acuity of the affected eye had improved at the latest follow-up examination (p = .018) in all patients. No recurrence of exudative RD occurred. Thinning of the CHs was observed in most patients; however, symptomatic radiation toxicity had not developed in any of the patients. Conclusion: Symptomatic CHs can be safely and effectively managed with Gamma Knife radiosurgery using a marginal dose of 10 Gy.

  16. Experimental Bedrock Channel Incision: Scaling, Sculpture and Sediment Transport

    NASA Astrophysics Data System (ADS)

    Johnson, J. P.; Whipple, K. X.

    2004-12-01

    flux (all else held equal) causes renewed incision, but of an even narrower inner channel; increasing the sediment flux leads to inner channel deposition. Where erosion is most vigorous, sediment generally moving as saltating bedload becomes locally suspended by upward-directed mean flow. For example, swirling clouds of "bedload" particles are continuously suspended by vortices developed within potholes such that the upward flux of particles out of the potholes balance the total sediment flux through the flume. Potholes spontaneously form where average bed slope and fluid velocities were highest, dramatically accelerating the local erosion rate. Our experimental potholes are smaller in scale but morphologically strikingly similar to many observed in the field, and include features such as corkscrew grooves down the outside walls and a protruding horn at the pothole center. More generally, abrasion becomes focused in places where the flow is spatially accelerated, such as in scoops and bends with high curvature. The knife-edge margins and spatial distribution of erosional forms indicate abrupt transitions in erosional efficiency that are tightly coupled to near-bed fluid flow patterns, which in turn are strongly influenced by the erosional forms themselves. Our experiments suggest that, in highly sculpted bedrock channels, naturally developed bed roughness presents a physical length scale that is important to controlling the interaction between sediment impacts and the bed, rather than a length scale based explicitly on sediment transport and average flow conditions such as the saltation hop length.

  17. Relaxation Techniques.

    DTIC Science & Technology

    1985-04-01

    FUNDING/SPONSORING 18b. OFFICE SYMBOL 9. PROCUREMENT INSTRUMENT IDENTIFICATION NUMBER ORGANIZATION (If applicable) 8c ADDRESS f( t’, State and ZIP Code) 10...inhaling and exhaling to promote a feeling of relaxation that is used in yoga, LaMaze childbirth, and hypnosis . The sccond is progressive muscle

  18. Hillslope-derived blocks retard river incision

    NASA Astrophysics Data System (ADS)

    Shobe, Charles M.; Tucker, Gregory E.; Anderson, Robert S.

    2016-05-01

    The most common detachment-limited river incision models ignore the effects of sediment on fluvial erosion, yet steep reaches of mountain rivers often host clusters of large (>1 m) blocks. We argue that this distribution of blocks is a manifestation of an autogenic negative feedback in which fast vertical river incision steepens adjacent hillslopes, which deliver blocks to the channel. Blocks inhibit incision by shielding the bed and enhancing form drag. We explore this feedback with a 1-D channel-reach model in which block delivery by hillslopes depends on the river incision rate. Results indicate that incision-dependent block delivery can explain the block distribution in Boulder Creek, Colorado. The proposed negative feedback may significantly slow knickpoint retreat, channel adjustment, and landscape response compared to rates predicted by current theory. The influence of hillslope-derived blocks may complicate efforts to extract base level histories from river profiles.

  19. Minilaparotomy left iliac fossa skin crease incision vs. midline incision for left-sided colorectal cancer.

    PubMed

    Kam, M H; Seow-Choen, F; Peng, X H; Eu, K W; Tang, C L; Heah, S M; Ooi, B S

    2004-08-01

    Midline laparotomies offer excellent exposure but are associated with increased postoperative pain and longer recovery. A minilaparotomy resection of leftsided colorectal cancers was studied as an alternative approach. We performed a case-control retrospective review of 280 randomly selected patients (140 midline incisions; 140 left skin crease incisions) who underwent elective, curative resection of left-sided colorectal cancers. Patients in both groups were of comparable age and sex. The left skin crease incision was shorter (median length, 13.5 cm) than the midline incision (median length, 20.0 cm). Median operation time was less in the left skin crease group (75 min) than in the midline incision group (105 min). Similar types of operations were performed, including left hemicolectomies, sigmoid colectomies, anterior resections and ultra-low anterior resections. Adequacy of resection was confirmed by histological analysis, with no involvement of margins. The median numbers of lymph nodes removed were comparable: 10 for the skin crease incision group and 12 for the midline incision group. Postoperative parameters for the skin crease incision group showed that feeding, ambulation, narcotic use and hospital stay were significantly better than the parameters in the midline group. Complications of intestinal obstruction were also reduced in the skin crease incision group. The limited left skin crease incision provides adequate margins of clearance in colorectal cancers when compared to the midline incision, but has advantages of shorter operation time, earlier feeding and ambulation, and earlier discharge from hospital.

  20. [Design and application of silver needle-knife].

    PubMed

    Sun, Guodong; Shi, Bin; Zhang, Benwu; Xu, Haidong

    2015-04-01

    A silver needle-knife which has the dual function of silver needle and needle-knife is designed. The main components of this silver needle-knife are approximately 50% silver and approximately 50% nichrome. The silver needle-knife is composed of five parts, including needle-knife tail, spiral handle; steering handle, needle-knife body and needle-knife edge. It converges the advantages of needle-knife and silver needle, which can cut loose of diseased tissue and peel adhesion of lesions, but also be heated with moxa cone and thermal therapeutic instrument, and connect with electroacupuncture apparatus. It has the function of warming channel and removing coldness, dispelling wind and eliminating dampness, resolving spasm and relieving pain, dredging the channel and so on. Due to the spiral handle and the steering handle, the operation is easier, which reduces the blindness of cutting and increase the safety. It is mainly used for soft tissue injury, rheumatism and rheumatoid arthritis, as well as degenerative diseases of spine and joint, and it has obvious efficacy on some internal medical diseases.

  1. Knife River Indian Villages National Historic Site: Teacher's Guide.

    ERIC Educational Resources Information Center

    National Park Service (Dept. of Interior), Washington, DC. National Register of Historic Places.

    This guide provides history and social studies teachers, at all grade levels, with information and activities about the American Indians of the Northern Plains who lived in the area of the Knife River where it enters the Missouri River. Located in what is now North Dakota, this area is the Knife River Indian Villages National Historic Site. The…

  2. [SINGLE-INCISION TECHNIQUE FOR RIGHT HEMICOLECTOMY].

    PubMed

    Melnik, Idit; Dukhno, Oleg; Cohen, Ornit; Goldstein, Dimitry; Yoffe, Boris

    2016-08-01

    The single incision laparoscopic technique is an emerging modality. The aim of our study was to compare the intra-operative and short term post-operative outcomes of single incision versus multi-incision laparoscopy for right hemicolectomy. We retrospectively reviewed the charts of all patients who underwent right hemicolectomy from October 2010 till December 2012. Thirty six patients underwent laparoscopic right hemicolectomy, of which, twenty five were performed with the traditional multi-incision technique and eleven were conducted with a single incision. From the parameters that were evaluated, we found that in the single incision technique there was a statistical trend [p=0.08] of better oncological results with a higher mean lymph node extraction. In addition, there was a statistically significant [p=0.05] advantage of decreased length of hospitalization. The single incision technique is feasible and safe for right hemicolectomy. Given our findings, we believe that it can be an effective alternative to the traditional multi-port technique.

  3. Single incision pediatric flexible intramedullary tibial nailing.

    PubMed

    Coury, John G; Lum, Zachary C; O'Neill, Nicholas P; Gerardi, Joseph A

    2017-09-01

    There has been a trend towards flexible intramedullary nailing for unstable tibial shaft fractures in the pediatric population, traditionally, utilizing a 2-incision technique with passage of one nail medially and one nail laterally. Our study aims to compare a single incision approach for flexible nailing of unstable tibial shaft fractures in pediatric patients to the traditional 2-incision approach. Patients were selected for operative fixation if they had a length unstable tibial shaft fracture confirmed by fluoroscopy. Exclusion criteria included length stable tibial fractures that could undergo nonoperative treatment. Single incision technique utilized the medial incision only. Patients were monitored in the hospital for one postoperative day and followed up at 4 week, 8 week, and 12 week marks. Radiographic analysis was performed to evaluate for malunion or nonunion. Operative times, infection rates and complications were recorded and analyzed. All patients achieved complete fracture healing at the 12-week follow up. There were no delayed unions, nonunions or malunions in either treatment group. Single medial incision for tibial flexible nails had equivalent outcomes with no difference in primary healing rate, malunion or nonunion rate when compared to the dual incision technique.

  4. Natural orifice transluminal endoscopic wedge hepatic resection with a water-jet hybrid knife in a non-survival porcine model

    PubMed Central

    Shi, Hong; Jiang, Sheng-Jun; Li, Bin; Fu, Deng-Ke; Xin, Pei; Wang, Yong-Guang

    2011-01-01

    AIM: To explore the feasibility of a water-jet hybrid knife to facilitate wedge hepatic resection using a natural orifice transluminal endoscopic surgery (NOTES) approach in a non-survival porcine model. METHODS: The Erbe Jet2 water-jet system allows a needleless, tissue-selective hydro-dissection with a pre-selected pressure. Using this system, wedge hepatic resection was performed through three natural routes (trans-anal, trans-vaginal and trans-umbilical) in three female pigs weighing 35 kg under general anesthesia. Entry into the peritoneal cavity was via a 15-mm incision using a hook knife. The targeted liver segment was marked by an APC probe, followed by wedge hepatic resection performed using a water-jet hybrid knife with the aid of a 4-mm transparent distance soft cap mounted onto the tip of the endoscope for holding up the desired plane. The exposed vascular and ductal structures were clipped with Endoclips. Hemostasis was applied to the bleeding cut edges of the liver parenchyma by electrocautery. After the procedure, the incision site was left open, and the animal was euthanized followed by necropsy. RESULTS: Using the Erbe Jet2 water-jet system, trans-anal and trans-vaginal wedge hepatic resection was successfully performed in two pigs without laparoscopic assistance. Trans-umbilical attempt failed due to an unstable operating platform. The incision for peritoneal entry took 1 min, and about 2 h was spent on excision of the liver tissue. The intra-operative blood loss ranged from 100 to 250 mL. Microscopically, the hydro-dissections were relatively precise and gentle, preserving most vessels. CONCLUSION: The Erbe Jet2 water-jet system can safely accomplish non-anatomic wedge hepatic resection in NOTES, which deserves further studies to shorten the dissection time. PMID:21412502

  5. Natural orifice transluminal endoscopic wedge hepatic resection with a water-jet hybrid knife in a non-survival porcine model.

    PubMed

    Shi, Hong; Jiang, Sheng-Jun; Li, Bin; Fu, Deng-Ke; Xin, Pei; Wang, Yong-Guang

    2011-02-21

    To explore the feasibility of a water-jet hybrid knife to facilitate wedge hepatic resection using a natural orifice transluminal endoscopic surgery (NOTES) approach in a non-survival porcine model. The Erbe Jet2 water-jet system allows a needleless, tissue-selective hydro-dissection with a pre-selected pressure. Using this system, wedge hepatic resection was performed through three natural routes (trans-anal, trans-vaginal and trans-umbilical) in three female pigs weighing 35 kg under general anesthesia. Entry into the peritoneal cavity was via a 15-mm incision using a hook knife. The targeted liver segment was marked by an APC probe, followed by wedge hepatic resection performed using a water-jet hybrid knife with the aid of a 4-mm transparent distance soft cap mounted onto the tip of the endoscope for holding up the desired plane. The exposed vascular and ductal structures were clipped with Endoclips. Hemostasis was applied to the bleeding cut edges of the liver parenchyma by electrocautery. After the procedure, the incision site was left open, and the animal was euthanized followed by necropsy. Using the Erbe Jet2 water-jet system, trans-anal and trans-vaginal wedge hepatic resection was successfully performed in two pigs without laparoscopic assistance. Trans-umbilical attempt failed due to an unstable operating platform. The incision for peritoneal entry took 1 min, and about 2 h was spent on excision of the liver tissue. The intra-operative blood loss ranged from 100 to 250 mL. Microscopically, the hydro-dissections were relatively precise and gentle, preserving most vessels. The Erbe Jet2 water-jet system can safely accomplish non-anatomic wedge hepatic resection in NOTES, which deserves further studies to shorten the dissection time.

  6. [Clamshell thoracotomy after thoracic knife wounds].

    PubMed

    Rudolph, Marcus; Schneider, Niko R E; Popp, Erik

    2017-01-04

    Resuscitation in the event of traumatic cardiac arrest was for a long time considered to be a less than promising technique to employ; however, current data indicate that the prospects of success need not be any poorer than for resuscitation due to cardiac distress. The targeted and rapid remedying of reversible causes can re-establish the circulatory function and the European Resuscitation Council (ERC) algorithm for traumatic cardiac arrest is a helpful guide in this respect. This case report illustrates the resolute implementation of this algorithm in the prehospital environment in the case of an attempted suicide by a thoracic knife wound.

  7. Special indications in gamma knife surgery.

    PubMed

    Wowra, B; Muacevic, A; Müller-Schunk, S; Tonn, J C

    2004-01-01

    Pilocytic astrocytoma (PA) represent a rare indication for Gamma Knife Surgery. Mostly small remnants after surgical debulking are treated. The prognosis depends on specific variants of biological and clinical criteria. In this regard we differentiated two groups of tumors; the so-called 'typical' tumors with a histological grading of WHO Grade I, no prior fractionated radiotherapy and no cystic component and the so called 'atypical' tumors with either a malignant transformation, previous fractionated radiotherapy and/or cystic components. The outcome after GKS was much more favourable for typical PA than for atypical. In typical cases a high tumor control with a very low risk of side effects can be achieved.

  8. Low-power holmium:YAG laser urethrotomy for urethral stricture disease: comparison of outcomes with the cold-knife technique.

    PubMed

    Atak, Mustafa; Tokgöz, Hüsnü; Akduman, Bülent; Erol, Bülent; Dönmez, Ibrahim; Hancı, Volkan; Türksoy, Ozlem; Mungan, Necmettin Aydın

    2011-11-01

    In this prospective randomized clinical trial, we aimed to evaluate the safety and efficacy of endourethrotomy with holmium:yttrium-aluminium-garnet (HO:YAG) laser and compare the outcomes with the conventional cold-knife urethrotomy. Fifty-one male patients with single, iatrogenic, annular strictures of the urethra were randomly divided into two groups; 21 patients who underwent direct-vision endoscopic urethrotomy with Ho:YAG laser (15 W; 1,200-1,400 mJ; 8-12 Hz) at 12 o'clock position (laser group) and 30 patients who underwent direct-vision endoscopic urethrotomy with cold-knife incision at 12 o'clock position (cold-knife group). The results obtained were analyzed and compared at 3 months, 6 months, 9 months, and 12 months postoperatively by clinical evaluation, uroflowmetry, and retrograde urethrographies. Variables were compared among groups using Fisher's exact and Mann Whitney U tests. There were no differences between two groups in terms of patient age, preoperative Qmax value, stricture location, and length. Operative time was shorter in laser group (16.4 ± 8.04 minutes) when compared with cold-knife group (23.8 ± 5.47 minutes) (p<0.001). Recurrence-free rate at 3 months was similar between two groups (p=0.122). However, recurrence-free rates at 6 months, 9 months, and 12 months were significantly higher in laser group when compared with cold-knife group (p values were 0.045, 0.027, and 0.04, respectively). No intra- or postoperative complications were encountered. Use of Ho:YAG laser in the management of urethral stricture disease is a safe and effective method. In addition, it provides shorter operative time and lower recurrence rate when compared with the conventional technique. Copyright © 2011. Published by Elsevier B.V.

  9. Direct withdrawal of a knife lodged in the thoracic spinal canal in a patient with normal neurologic examination: is it safe?

    PubMed

    Sakar, Mustafa; Dogrul, Ramazan; Niftaliyev, Seymur; Bayri, Yasar; Dagcınar, Adnan

    2016-01-01

    Stab wound injuries to the spinal cord are rare, although they commonly cause complete or incomplete neurological deficits. Normal neurological examination with a knife traversing the spinal canal is extremely rare. Here we report on a patient with a knife lodged in the thoracic spine with normal neurological examination and describe direct withdrawal of the knife with excellent results that have not been reported to date. A 50-year-old male patient was admitted to the emergency service because of his sustaining a stab wound to thoracic 3-4 level due to a knife traversing the spinal canal and still lodged in the vertebral bodies. His neurological examination was normal. The knife was withdrawn in the operating room under general anesthesia without bleeding or cerebrospinal fluid leakage. After withdrawal neurological examination was normal and control magnetic resonance imaging showed no abnormalities. Surgical exploration is suggested for spinal stab wounds if there is a retained body. Some authors recommend exploration even no foreign body is detected. Incomplete or complete cord injuries deserve surgical exploration, but in a patient with normal neurological examination direct withdrawal can be a safe option. Exploration of the wound surgically may have risks associated with enlarging the incision, muscle dissection, enlarging dural tear and bony removal, which may have long-term adverse effects. The operation team must be ready for urgent exploration. Cerebrospinal fluid leakage, excessive bleeding or any neurological deficit after removal must mandate surgical exploration. Long-term close follow-up of the patient has paramount importance for late complications such as infection and pseudomeningocele development.

  10. Clear Corneal Incision in Cataract Surgery

    PubMed Central

    Al Mahmood, Ammar M.; Al-Swailem, Samar A.; Behrens, Ashley

    2014-01-01

    Since the introduction of sutureless clear corneal cataract incisions, the procedure has gained increasing popularity worldwide because it offers several advantages over the traditional sutured scleral tunnels and limbal incisions. Some of these benefits include lack of conjunctival trauma, less discomfort and bleeding, absence of suture-induced astigmatism, and faster visual rehabilitation. However, an increasing incidence of postoperative endophthalmitis after clear corneal cataract surgery has been reported. Different authors have shown a significant increase up to 15-fold in the incidence of endophthalmitis following clear corneal incision compared to scleral tunnels. The aim of this report is to review the advantages and disadvantages of clear corneal incisions in cataract surgery, emphasizing on wound construction recommendations based on published literature. PMID:24669142

  11. The oblique mastectomy incision: advantages and outcomes.

    PubMed

    Gronet, Edward M; Halvorson, Eric G

    2014-01-01

    Mastectomy has traditionally been performed using a transverse elliptical incision. The disadvantages of this approach are a potentially visible scar medially and poor subincisional soft-tissue coverage of implants laterally. A more natural and aesthetic result is obtained with an oblique incision running parallel to the pectoralis major muscle fibers. This approach offers women more freedom of choice in clothing as well as the potential for complete subincisional muscle coverage in alloplastic breast reconstruction, in addition to other functional advantages.

  12. Knife and impact cutting of lamb bone.

    PubMed

    King, M J

    1999-05-01

    The forces and hence fracture energies required to cut bone are presented in this paper and the merits of cutting with a high speed blade are considered. A plain knife blade was used to cut cancellous and compact lamb bone using three different methods. A microtome was used to produce a range of cut thicknesses which enabled the fracture energy to be separated into friction, surface fracture and plastic deformation energies. A tensile test machine was used to produce thicker off-cuts so that the energy required to cut through full sections of bone could be determined. A high speed rail gun was used to cut at speeds up to 130 m/s. The energy required to cut bone did not change with blade speed. However, the energies measured during the cutting varied over a wide range. In situations in which the surface of the cut bone exhibited a very uneven surface high energy was required, whereas when the resulting cut surface was planar the cutting energy was low. A light weight blade which impacts the bone at high speed will transmit a small impulse to the carcass which may be absorbed without transmitting strain to the muscle/connective tissue. This may allow the development of a high speed knife which will cut bone without excessively damaging the meat surrounding the cut.

  13. [CyberKnife can cause inappropriate shock].

    PubMed

    Cakmak, Nazmiye; Yılmaz, Hale; Sayar, Nurten; Erer, Betül

    2012-12-01

    Implantable cardioverter-defibrillators (ICD) have been increasingly used to treat life-threatening ventricular tachyarrhythmias. Although they have life-saving capabilities, they are very sensitive to electromagnetic energy sources. It has been reported that many problems associated with the detection of tachyarrhythmias and termination of the mechanism of the ICDs occur due to electromagnetic interference (EMI). In spite of the fact that EMI has been decreasingly observed with the latest generation ICDs, problems may still occur during radiotherapy. The CyberKnife is the latest stereotactic radio-surgery technology in the field of radiotherapy, and is currently being used for the treatment of malign neoplasm in the body. It is especially preferred for the treatment of advanced stage and metastatic tumors. Five ICD shocks were detected in a patient during a routine follow-up visit. When the patient was evaluated, it was determined that he underwent radiotherapy with CyberKnife technology because of lung metastasis and rectal adenocarcinoma. He received the ICD shocks while he was on radiotherapy. When the stored intracardiac electrograms in the memory of the ICD were investigated, it was established that the shocks were inappropriate shocks due to oversensing because of the exposure to EMI.

  14. The gamma knife in ophthalmology. Part One--Uveal melanoma.

    PubMed

    Wygledowska-Promieńska, Dorota; Jurys, Małgorzata; Wilczyński, Tomasz; Drzyzga, Łukasz

    2014-01-01

    The Gamma Knife was designed by Lars Leksell in the early 1950's. It gave rise to a new discipline of medicine--stereotactic radiosurgery. Primarily dedicated to neurosurgery, the Gamma Knife has become an alternative, widely used surgery technique. According to Elekta's statistics, approximately 60,000 people are treated with Leksell Gamma Knife every year and it is the most extensively studied stereotactic radiosurgery system in the world. The Leksell Gamma Knife can also be used in ophthalmology. The gamma ray beam concentration enables effective treatment of uveal melanoma, choroidal hemangioma, orbital tumors or even choroidal neovascularization. The virtue of Leksell Gamma Knife is its extreme precision, non-invasiveness and the possibility of outpatient treatment, which significantly reduces costs and diminishes post-operative complications. Innovative solutions shorten a single session to a minimum, which is very comfortable and safe for both staff and patients. Advantages and possible side effects of gamma knife radiosurgery are well-documented in the professional literature. The objective of this review is to present the recognized applications of Leksell Gamma Knife in ophthalmology.

  15. A nurse clinician's approach to knife crime prevention.

    PubMed

    England, Rachel; Jackson, Rob

    This article outlines a new and creative contribution to knife crime prevention by an emergency nurse clinician and an initial evaluation of its effectiveness. The 'knife crime prevention programme' is delivered to young people aged 11-16 years by one of the authors, Rob Jackson, an emergency nurse clinician at Liverpool University Hospital; the aim is to educate young people about the medical consequences of knife injury. A group of 140 students and 17 teachers responded to a questionnaire evaluating the effectiveness of the session delivered to four schools in Liverpool. Students and teachers positively rated the session, with the combination of the nurse clinician's knowledge and expertise and photographs and depictions of knife crime as a unique and impacting approach to knife crime prevention. It is suggested that the nurse clinician and other experienced health professionals have an important contribution to make in preventive approaches to knife crime. Further evaluation of the knife crime prevention programme will be conducted by the authors.

  16. Partial Superficial Parotidectomy via Retroauricular Hairline Incision.

    PubMed

    Kim, Do-Youn; Park, Gi Cheol; Cho, Young-Wook; Choi, Seung-Ho

    2014-06-01

    The purpose of this study was to evaluate the usefulness of retroauricular hair line incision (RAHI) in partial superficial parotidectomy by comparison with modified Blair incision or facelift incision. Medical records of 73 patients with benign parotid tumor who underwent partial superficial parotidectomy were retrospectively reviewed. Size and location of tumors, operative time, occurrence of facial nerve paralysis and Frey's syndrome, and cosmetic outcomes were compared among RAHI, facelift incision (FLI), modified Blair incision (MBI) groups. RAHI group showed better cosmetic results than FLI group or MBI group compared with other type of incisions (P<0.001, P<0.001, respectively). Among the 3 groups, there were no significant differences of operative time and location of tumor (P=0.377), size of tumor (P>0.999), occurrence of temporary or permanent facial nerve paralysis (P=0.745) and Frey's syndrome (P=0.940). Partial superficial parotidectomy can be done safely by RAHI in most cases of benign parotid tumor. Compared with MBI or FLI, RAHI has better cosmetic outcome with no increase of operative time or postoperative complications.

  17. Partial Superficial Parotidectomy via Retroauricular Hairline Incision

    PubMed Central

    Kim, Do-Youn; Park, Gi Cheol; Cho, Young-Wook

    2014-01-01

    Objectives The purpose of this study was to evaluate the usefulness of retroauricular hair line incision (RAHI) in partial superficial parotidectomy by comparison with modified Blair incision or facelift incision. Methods Medical records of 73 patients with benign parotid tumor who underwent partial superficial parotidectomy were retrospectively reviewed. Size and location of tumors, operative time, occurrence of facial nerve paralysis and Frey's syndrome, and cosmetic outcomes were compared among RAHI, facelift incision (FLI), modified Blair incision (MBI) groups. Results RAHI group showed better cosmetic results than FLI group or MBI group compared with other type of incisions (P<0.001, P<0.001, respectively). Among the 3 groups, there were no significant differences of operative time and location of tumor (P=0.377), size of tumor (P>0.999), occurrence of temporary or permanent facial nerve paralysis (P=0.745) and Frey's syndrome (P=0.940). Conclusion Partial superficial parotidectomy can be done safely by RAHI in most cases of benign parotid tumor. Compared with MBI or FLI, RAHI has better cosmetic outcome with no increase of operative time or postoperative complications. PMID:24917908

  18. Peripheral dose in ocular treatments with CyberKnife and Gamma Knife radiosurgery compared to proton radiotherapy

    NASA Astrophysics Data System (ADS)

    Zytkovicz, A.; Daftari, I.; Phillips, T. L.; Chuang, C. F.; Verhey, L.; Petti, P. L.

    2007-09-01

    Peripheral radiation can have deleterious effects on normal tissues throughout the body, including secondary cancer induction and cataractogenesis. The aim of this study is to evaluate the peripheral dose received by various regions of the body after ocular treatment delivered with the Model C Gamma Knife, proton radiotherapy with a dedicated ocular beam employing no passive-scattering system, or a CyberKnife unit before and after supplemental shielding was introduced. TLDs were used for stray gamma and x-ray dosimetry, whereas CR-39 dosimeters were used to measure neutron contamination in the proton experiments. Doses to the contralateral eye, neck, thorax and abdomen were measured on our anthropomorphic phantom for a 56 Gy treatment to a 588 mm3 posterior ocular lesion. Gamma Knife (without collimator blocking) delivered the highest dose in the contralateral eye, with 402-2380 mSv, as compared with 118-234 mSv for CyberKnife pre-shielding, 46-255 mSv for CyberKnife post-shielding and 9-12 mSv for proton radiotherapy. Gamma Knife and post-shielding CyberKnife delivered comparable doses proximal to the treatment site, with 190 versus 196 mSv at the thyroid, whereas protons doses at these locations were less than 10 mSv. Gamma Knife doses decreased dramatically with distance from the treatment site, delivering only 13 mSv at the lower pelvis, comparable to the proton result of 4 to 7 mSv in this region. In contrast, CyberKnife delivered between 117 and 132 mSv to the lower pelvis. In conclusion, for ocular melanoma treatments, a proton beam employing no double scattering system delivers the lowest peripheral doses proximally to the contralateral eye and thyroid when compared to radiosurgery with the Model C Gamma Knife or CyberKnife. At distal locations in the pelvis, peripheral doses delivered with proton and Gamma Knife are of an order of magnitude smaller than those delivered with CyberKnife.

  19. Embolization with Gamma Knife Radiosurgery of Giant Intracranial Arteriovenous Malformations.

    PubMed

    Chun, Dong Hyun; Kim, Moo Seong; Kim, Sung Tae; Paeng, Sung Hwa; Jeong, Hae Woong; Lee, Won Hee

    2016-01-01

    Giant arteriovenous malformations (i.e., those greater than 6 cm maximum diameter or volume > 33 cc) are difficult to treat and often carry higher treatment morbidity and mortality rates. In our study, we reviewed the angiographic results and clinical outcomes for 11 patients with giant arteriovenous malformations who were treated between 1994 and 2012. The patients selected included 9 males (82%) and 2 females (18%). Their presenting symptoms were hemorrhage (n=2; 18%), seizure (n=7; 64%), and headache (n=2; 12%). Nine patients were Spetzler-Martin Grade III, 2 were Spetzler-Martin Grade IV. The mean arteriovenous malformation volume was 41 cc (33-52 cc). The mean age of the patients was 45.1 years (24-57 years) and the mean radiation dose delivered to the margin of the nidus was 14.2 Gy. Ten patients received pre-Gamma Knife radiosurgery embolization and Gamma Knife radiosurgery, 1 patient received pre-Gamma Knife radiosurgery embolization and Gamma Knife radiosurgery twice and the interval between Gamma Knife radiosurgeries was 3 months. The complete obliteration rate following Gamma Knife radiosurgery was 36%, subtotal obliteration ( > 70% decreased size of nidus) was 36%, and partial obliteration was 28%. One patient experienced a small hemorrhage after embolization. Combined embolization and Gamma Knife radiosurgery showed successful obliteration of the arteriovenous malformation nidus. The use of embolization to initially reduce nidus size followed by Gamma Knife radiosurgery improves the treatment results. Repeated Gamma Knife radiosurgery should be a treatment option when there is a small nidus remnant.

  20. Natural relaxation

    NASA Astrophysics Data System (ADS)

    Marzola, Luca; Raidal, Martti

    2016-11-01

    Motivated by natural inflation, we propose a relaxation mechanism consistent with inflationary cosmology that explains the hierarchy between the electroweak scale and Planck scale. This scenario is based on a selection mechanism that identifies the low-scale dynamics as the one that is screened from UV physics. The scenario also predicts the near-criticality and metastability of the Standard Model (SM) vacuum state, explaining the Higgs boson mass observed at the Large Hadron Collider (LHC). Once Majorana right-handed neutrinos are introduced to provide a viable reheating channel, our framework yields a corresponding mass scale that allows for the seesaw mechanism as well as for standard thermal leptogenesis. We argue that considering singlet scalar dark matter extensions of the proposed scenario could solve the vacuum stability problem and discuss how the cosmological constant problem is possibly addressed.

  1. Nonvisualization of sterile surgical incisions with indium-111 labeled leukocytes

    SciTech Connect

    Abdel-Nabi, H.; Hinkle, G.H.; Olsen, J.O.

    1985-09-01

    The localization of In-111 labeled leukocytes (WBCs) in recent surgical incisions was studied in 18 patients. In-111 WBC images correlated well with culture results and clinical findings. No accumulation of In-111 WBCs was detected at the site of noninfected incisions in nine patients. In-111 WBCs did accumulate at incision sites in nine patients with infected surgical incisions. These results indicate that In-111 WBC study can accurately distinguish between normal healing and infection of recent surgical incisions.

  2. Bark Separation During Chipping With a Parallel Knife Chipper

    Treesearch

    John R. Erickson

    1968-01-01

    Five winter-cut northern species were chipped in a frozen and unfrozen condition with a parallel knife chipper. The degree of bark separation during chipping and a relative gradation of chip size are reported.

  3. How Sharp Does a "Knife Edge" Have to Be?

    ERIC Educational Resources Information Center

    Dietz, Eric R.; Gash, Philip W.

    1994-01-01

    Describes an experiment designed to help understand the effect of the curvature of the laboratory equipment support (cylindrical rod instead of knife-edge) on the frequency of oscillation of pendula. (ZWH)

  4. Neck Dissection Through a Facelift Incision

    PubMed Central

    Melvin, Thuy-Anh N.; Eliades, Steven J.; Ha, Patrick K.; Fakhry, Carole; Saunders, John M.; Califano, Joseph A.; Blanco, Ray G. F.

    2013-01-01

    Obectives/Hypothesis To determine the feasibility and safety of neck dissection through a facelift incision. Study Design Prospective case series. Methods Cadavers and live subjects underwent neck dissection using a facelift incision with and without endoscopic assistance. In the live facelift neck dissection (FLND), the preoperative surgical indications, staging, adjuvant therapy, intraoperative technical procedure, pathology reports on lymph nodes, and short-term outcomes were reviewed. Results FLND was successfully performed in four cadavers and four live subjects, including selective (less than five neck levels removed) and comprehensive (levels I–V removed) neck dissections. All levels were accessible through this approach, with additional retraction required for levels I and IV. Endoscopic assistance was required in one neck dissection for adequate visualization. Short-term complications and number of excised lymph nodes were comparable to those from traditional neck dissection approaches. Conclusions Open neck dissection through a facelift incision is feasible and offers an alternate approach to traditional incisions. This can be performed without requiring robotic assistance and with endoscopic assistance only in certain cases. Endoscopic assistance can offer enhanced visualization of the surgical field and complement open direct approaches in neck dissection. Although FLND offers improved cosmetic outcomes when compared to those of traditional neck incisions, further study is required to determine its efficacy and indications. PMID:23023877

  5. The treatment of tongue haemangioma by plasma knife surgery.

    PubMed

    Kutluhan, A; Bozdemir, K; Ugras, S

    2008-11-01

    A seven-year-old girl presented with a 4 cm x 2 cm lesion of the tongue which was located at the posterior one-third in the midline. The lesion was excised by plasma knife surgery. No complication, such as bleeding, shortness of breath or infection, occurred after the treatment. Plasma knife surgery is an acceptable choice for selected benign lingual vascular malformations.

  6. Optical knife-edge technique for nanomechanical displacement detection

    SciTech Connect

    Karabacak, D.; Kouh, T.; Huang, C.C.; Ekinci, K.L.

    2006-05-08

    We describe an optical knife-edge technique for nanomechanical displacement detection. Here, one carefully focuses a laser spot on a moving edge and monitors the reflected power as the edge is displaced sideways. To demonstrate nanomechanical displacement detection using the knife-edge technique, we have measured in-plane resonances of nanometer scale doubly clamped beams. The obtained displacement sensitivity is in the {approx}1 pm/{radical}(Hz) range--in close agreement with a simple analytical model.

  7. A prospective randomized study in 20 patients undergoing bilateral TKA comparing midline incision to anterolateral incision.

    PubMed

    Maniar, Rajesh N; Singhi, Tushar; Nanivadekar, Arun; Maniar, Parul R; Singh, Jaivardhan

    2017-02-11

    Lateral flap numbness is a known side-effect of midline skin incision in total knee arthroplasty (TKA) and a cause of patient dissatisfaction. Anterolateral incision is an alternative approach which preserves the infrapatellar branches of the saphenous nerve and avoids numbness. Studies have compared both incisions, but in different patients. However, different patients may assess the same sensory deficit dissimilarly, because of individual variations in anatomy and healing responses. We compared the two incisions in the same patient at the same time, using an anterolateral incision on one knee and a midline incision on the other knee in simultaneous bilateral TKA. Other surgical steps including medial arthrotomy were idential. We also correlated subjective and objective findings. Twenty patients were prospectively randomized. Sensory loss and skin healing were assessed at 6, 12 and 52 weeks. Subjective preference for the knee with less numbness was charted on Wald's Sequential Probability Ratio Test. Sensation scores for touch, vibration, static and moving two-point discrimination were measured. Scar healing was evaluated using the Patient and Observer Scar Assessment Scale (POSAS). Functional scores were measured. A statistically significant difference favoring knees with anterolateral incision was observed in patient preference at all assessment points and this correlated with sensation scores. A statistically significant difference was observed in POSAS score favoring knees with anterolateral incision at 6 and 12 weeks which became statistically insignificant at 1 year. Functional scores remained comparable. We recommend anterolateral incision as a safe and effective method to circumvent the problem of lateral flap numbness with midline incision. I.

  8. La relaxation en pedagogie (Relaxation in Teaching).

    ERIC Educational Resources Information Center

    Dufeu, Bernard

    1989-01-01

    A discussion of the use of relaxation techniques in the language classroom outlines the reasons for their use and specifies procedures for relaxation either lying down or seated as a prelude to instruction. (MSE)

  9. Treatment of epidermoid tumors with gamma knife radiosurgery: Case series

    PubMed Central

    Vasquez, Javier A. Jacobo; Fonnegra, Julio R.; Diez, Juan C.; Fonnegra, Andres

    2016-01-01

    Background: Epidermoid tumors (ETs) are benign lesions that are treated mainly by means of surgical resection, with overall good results. External beam radiotherapy is an alternative treatment for those recurrent tumors, in which a second surgery might not be the best choice for the patient. A little information exists about the effectiveness of gamma knife radiosurgery for the treatment of newly diagnosed and recurrent ETs. We present three cases of ETs treated with gamma knife radiosurgery. Case Description: Case 1 is a 21-year-old female with an ET located in the left cerebellopontine angle (CPA) with symptoms related to VIII cranial nerve dysfunction. Symptom control was achieved and maintained after single session radiosurgery with gamma knife. Case 2 is a 59-year-old female patient with the history of trigeminal neuralgia secondary to a recurrent ET located in the left CPA. Significant pain improvement was achieved after treatment with gamma knife radiosurgery. Case 3 is a 29-year-old male patient with a CPA ET causing long lasting trigeminal neuralgia, pain relief was achieved in this patient after gamma knife radiosurgery. Conclusion: Long-term symptom relief was achieved in all three cases proving that gamma knife radiosurgery is a good and safe alternative for patients with recurrent or nonsurgically treated ETs. PMID:26958427

  10. Treatment of epidermoid tumors with gamma knife radiosurgery: Case series.

    PubMed

    Vasquez, Javier A Jacobo; Fonnegra, Julio R; Diez, Juan C; Fonnegra, Andres

    2016-01-01

    Epidermoid tumors (ETs) are benign lesions that are treated mainly by means of surgical resection, with overall good results. External beam radiotherapy is an alternative treatment for those recurrent tumors, in which a second surgery might not be the best choice for the patient. A little information exists about the effectiveness of gamma knife radiosurgery for the treatment of newly diagnosed and recurrent ETs. We present three cases of ETs treated with gamma knife radiosurgery. Case 1 is a 21-year-old female with an ET located in the left cerebellopontine angle (CPA) with symptoms related to VIII cranial nerve dysfunction. Symptom control was achieved and maintained after single session radiosurgery with gamma knife. Case 2 is a 59-year-old female patient with the history of trigeminal neuralgia secondary to a recurrent ET located in the left CPA. Significant pain improvement was achieved after treatment with gamma knife radiosurgery. Case 3 is a 29-year-old male patient with a CPA ET causing long lasting trigeminal neuralgia, pain relief was achieved in this patient after gamma knife radiosurgery. Long-term symptom relief was achieved in all three cases proving that gamma knife radiosurgery is a good and safe alternative for patients with recurrent or nonsurgically treated ETs.

  11. Pallidotomy with the gamma knife: a positive experience.

    PubMed

    Young, R F; Vermeulen, S; Posewitz, A; Shumway-Cook, A

    1998-10-01

    51 patients with medically refractory Parkinson's disease underwent stereotactic posteromedial pallidotomy between August 1993 and February 1997 for treatment of bradykinesia, rigidity, and L-DOPA-induced dyskinesias. In 29 patients, the pallidotomies were performed with the Leksell Gamma Knife and in 22 they were performed with the standard radiofrequency (RF) method. Clinical assessment as well as blinded ratings of Unified Parkinson's Disease Rating Scale (UPDRS) scores were carried out pre- and postoperatively. Mean follow-up time is 20.6 months (range 6-48) and all except 4 patients have been followed more than one year. 85 percent of patients with dyskinesias were relieved of symptoms, regardless of whether the pallidotomies were performed with the Gamma Knife or radiofrequency methods. About 2/3 of the patients in both Gamma Knife and radiofrequency groups showed improvements in bradykinesia and rigidity, although when considered as a group neither the Gamma Knife nor the radiofrequency group showed statistically significant improvements in UPDRS scores. One patient in the Gamma Knife group (3.4%) developed a homonymous hemianopsia 9 months following treatment and 5 patients (27.7%) in the radiofrequency group became transiently confused postoperatively. No other complications were seen. Gamma Knife pallidotomy is as effective as radiofrequency pallidotomy in controlling certain of the symptoms of Parkinson's disease. It may be the only practical technique available in certain patients, such as those who take anticoagulants, have bleeding diatheses or serious systemic medical illnesses. It is a viable option for other patients as well.

  12. Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: A pilot animal study

    PubMed Central

    Jiang, Sheng-Jun; Shi, Hong; Swar, Gyanendra; Wang, Hai-Xia; Liu, Xiao-Jing; Wang, Yong-Guang

    2013-01-01

    AIM: To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model. METHODS: Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endsocope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation. RESULTS: Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure. CONCLUSION: Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation. PMID:24187461

  13. Trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife: a pilot animal study.

    PubMed

    Jiang, Sheng-Jun; Shi, Hong; Swar, Gyanendra; Wang, Hai-Xia; Liu, Xiao-Jing; Wang, Yong-Guang

    2013-10-28

    To investigate the feasibility and safety of Natural orifice trans-umbilical endoscopic cholecystectomy with a water-jet hybrid-knife in a non-survival porcine model. Pure natural orifice transluminal endoscopic surgery (NOTES) cholecystectomy was performed on three non-survival pigs, by transumbilical approach, using a water-jet hybrid-knife. Under general anesthesia, the following steps detailed the procedure: (1) incision of the umbilicus followed by the passage of a double-channel flexible endoscope through an overtube into the peritoneal cavity; (2) establishment of pneumoperitoneum; (3) abdominal exploration; (4) endoscopic cholecystectomy: dissection of the gallbladder performed using water jet equipment, ligation of the cystic artery and duct conducted using nylon loops; and (5) necropsy with macroscopic evaluation. Transumbilical endoscopic cholecystectomy was successfully completed in the first and third pig, with minor bleedings. The dissection times were 137 and 42 min, respectively. The total operation times were 167 and 69 min, respectively. And the lengths of resected specimen were 6.5 and 6.1 cm, respectively. Instillation of the fluid into the gallbladder bed produced edematous, distended tissue making separation safe and easy. Reliable ligation using double nylon loops insured the safety of cutting between the loops. There were no intraoperative complications or hemodynamic instability. Uncontrolled introperative bleeding occurred in the second case, leading to the operation failure. Pure NOTES trans-umbilical cholecystectomy with a water-jet hybrid-knife appears to be feasible and safe. Further investigation of this technique with long-term follow-up in animals is needed to confirm the preliminary observation.

  14. Breathing and Relaxation

    MedlinePlus

    ... Home Health Insights Stress & Relaxation Breathing and Relaxation Breathing and Relaxation Make an Appointment Ask a Question ... level is often dependent on his or her breathing pattern. Therefore, people with chronic lung conditions may ...

  15. Single incision laparoscopic splenectomy with double port.

    PubMed

    Vatansev, Celalettin; Ece, Ilhan

    2009-12-01

    In response to the increasing interest in minimally invasive surgery by both patients and surgeons, most abdominal surgery today is carried out laparoscopically. Laparoscopic splenectomy has become a gold standard in the treatment of spleen disorders related to hematologic diseases. Increasing laparoscopic surgery experience and improved new vessel sealing equipment have led to a decreasing number of ports in laparoscopic surgery and to operations from 1 incision. We carried out single-incision double-port laparoscopic splenectomy in a patient with immune thrombocytopenic purpura using only 2 trocars with a simple manipulation. Our review of the related literature revealed no earlier description of a single-incision double-port laparoscopic splenectomy. We therefore present herein this earlier unreported technique.

  16. Single incision endoscopic surgery for lumbar hernia.

    PubMed

    Kawaguchi, Masahiko; Ishikawa, Norihiko; Shimizu, Satsuki; Shin, Hisato; Matsunoki, Aika; Watanabe, Go

    2011-01-01

    Single Incision Endoscopic Surgery (SIES) has emerged as a less invasive surgery among laparoscopic surgeries, and this approach for incisional hernia was reported recently. This is the first report of SIES for an incisional lumbar hernia. A 66-year-old Japanese woman was referred to our institution because of a left flank hernia that developed after left iliac crest bone harvesting. A 20-mm incision was created on the left side of the umbilicus and all three trocars (12, 5, and 5 mm) were inserted into the incision. The hernial defect was 14 × 9 cm and was repaired with intraperitoneal onlay mesh and a prosthetic graft. The postoperative course was uneventful. SIES for lumbar hernia offers a safe and effective outcome equivalent compared to laparoscopic surgery. In addition, SIES is less invasive and has a cosmetic benefit.

  17. Combination of water-jet dissection and needle-knife as a hybrid knife simplifies endoscopic submucosal dissection.

    PubMed

    Lingenfelder, Tobias; Fischer, Klaus; Sold, Moritz G; Post, Stefan; Enderle, Markus D; Kaehler, Georg F B A

    2009-07-01

    The safety and efficacy of endoscopic submucosal dissection (ESD) is very dependent on an effective injection beneath the submucosal lamina and on a controlled cutting technique. After our study group demonstrated the efficacy of the HydroJet in needleless submucosal injections under various physical conditions to create a submucosal fluid cushion (Selective tissue elevation by pressure = STEP technique), the next step was to develop a new instrument to combine the capabilities of an IT-Knife with a high-pressure water-jet in a single instrument. In this experimental study, we compared this new instrument with a standard ESD technique. Twelve gastric ESD were performed in six pigs under endotracheal anesthesia. Square areas measuring 4-cm x 4-cm were marked out on the anterior and posterior wall in the corpus-antrum transition region. The HybridKnife was used as an standard needle knife with insulated tip (i.e., the submucosal injection was performed with an injection needle and only the radiofrequency (RF) part of the HybridKnife was used for cutting (conventional technique)) or the HybridKnife was used in all the individual stages of the ESD, making use of the HybridKnife's combined functions (HybridKnife technique). The size of the resected specimens, the operating time, the frequency with which instruments were changed, the number of bleeding episodes, and the number of injuries to the gastric wall together with the subjective overall assessment of the intervention by the operating physician were recorded. The resected specimens were the same size, with average sizes of 16.96 cm(2) and 15.85 cm(2) resp (p = 0.8125). Bleeding episodes have been less frequent in the HybridKnife group (2.83 vs. 3.5; p = 0.5625). The standard knife caused more injuries to the lamina muscularis propria (0.17 vs. 1.33; p = 0.0313). The operating times had a tendency to be shorter with the HybridKnife technique (47.18 vs. 58.32 minute; p = 0.0313). The combination of a needle-knife

  18. Relaxation Assessment with Varied Structured Milieu (RELAX).

    ERIC Educational Resources Information Center

    Cassel, Russell N.; Cassel, Susie L.

    1983-01-01

    Describes Relaxation Assessment with Varied Structured Milieu (RELAX), a clinical program designed to assess the degree to which an individual is able to demonstrate self-control for overall general relaxation. The program is designed for use with the Cassel Biosensors biofeedback equipment. (JAC)

  19. Relaxation Assessment with Varied Structured Milieu (RELAX).

    ERIC Educational Resources Information Center

    Cassel, Russell N.; Cassel, Susie L.

    1983-01-01

    Describes Relaxation Assessment with Varied Structured Milieu (RELAX), a clinical program designed to assess the degree to which an individual is able to demonstrate self-control for overall general relaxation. The program is designed for use with the Cassel Biosensors biofeedback equipment. (JAC)

  20. Usefulness of a novel slim type FlushKnife-BT over conventional FlushKnife-BT in esophageal endoscopic submucosal dissection

    PubMed Central

    Ohara, Yoshiko; Toyonaga, Takashi; Hoshi, Namiko; Tanaka, Shinwa; Baba, Shinichi; Takihara, Hiroshi; Kawara, Fumiaki; Ishida, Tsukasa; Morita, Yoshinori; Umegaki, Eiji; Azuma, Takeshi

    2017-01-01

    AIM To investigated the usefulness of a novel slim type ball-tipped FlushKnife (FlushKnife-BTS) over ball-tipped FlushKnife (FlushKnife-BT) in functional experiments and clinical practice. METHODS In order to evaluate the functionality of FlushKnife-BTS, water aspiration speed, resistance to knife insertion through the scope, and waterjet flushing speed were compared between FlushKnife-BTS and BT. In clinical practice, esophageal endoscopic submucosal dissection (ESD) performed using FlushKnife-BTS or BT by an experienced endoscopist between October 2015 and January 2016 were retrospectively reviewed. The treatment speed and frequency of removing and reinserting the knife to aspirate fluid and air during ESD sessions were analyzed. RESULTS Functional experiments revealed that water aspiration speed by the endoscope equipped with a 2.8-mm working channel with FlushKnife-BTS was 7.7-fold faster than that with conventional FlushKnife-BT. Resistance to knife insertion inside the scope with a 2.8-mm working channel was reduced by 40% with FlushKnife-BTS. The waterjet flushing speed was faster with the use of FlushKnife-BT. In clinical practice, a comparison of 6 and 7 ESD using FlushKnife-BT and BTS, respectively, revealed that the median treatment speed was 25.5 mm2/min (range 19.6-30.3) in the BT group and 44.2 mm2/min (range 15.5-55.4) in the BTS group (P = 0.0633). However, the median treatment speed was significantly faster with FlushKnife-BTS when the resection size was larger than 1000 m2 (n = 4, median 24.2 mm2/min, range 19.6-27.7 vs n = 4, median 47.4 mm2/min, range 44.2-55.4, P = 0.0209). The frequency of knife replacement was less in the BTS group (median 1.76 times in one hour, range 0-5.45) than in the BT group (7.02 times in one hour, range 4.23-15) (P = 0.0065). CONCLUSION Our results indicate that FlushKnife-BTS enhances the performance of ESD, particularly for large lesions, by improving air and fluid aspiration and knife insertion during ESD and

  1. Usefulness of a novel slim type FlushKnife-BT over conventional FlushKnife-BT in esophageal endoscopic submucosal dissection.

    PubMed

    Ohara, Yoshiko; Toyonaga, Takashi; Hoshi, Namiko; Tanaka, Shinwa; Baba, Shinichi; Takihara, Hiroshi; Kawara, Fumiaki; Ishida, Tsukasa; Morita, Yoshinori; Umegaki, Eiji; Azuma, Takeshi

    2017-03-07

    To investigated the usefulness of a novel slim type ball-tipped FlushKnife (FlushKnife-BTS) over ball-tipped FlushKnife (FlushKnife-BT) in functional experiments and clinical practice. In order to evaluate the functionality of FlushKnife-BTS, water aspiration speed, resistance to knife insertion through the scope, and waterjet flushing speed were compared between FlushKnife-BTS and BT. In clinical practice, esophageal endoscopic submucosal dissection (ESD) performed using FlushKnife-BTS or BT by an experienced endoscopist between October 2015 and January 2016 were retrospectively reviewed. The treatment speed and frequency of removing and reinserting the knife to aspirate fluid and air during ESD sessions were analyzed. Functional experiments revealed that water aspiration speed by the endoscope equipped with a 2.8-mm working channel with FlushKnife-BTS was 7.7-fold faster than that with conventional FlushKnife-BT. Resistance to knife insertion inside the scope with a 2.8-mm working channel was reduced by 40% with FlushKnife-BTS. The waterjet flushing speed was faster with the use of FlushKnife-BT. In clinical practice, a comparison of 6 and 7 ESD using FlushKnife-BT and BTS, respectively, revealed that the median treatment speed was 25.5 mm(2)/min (range 19.6-30.3) in the BT group and 44.2 mm(2)/min (range 15.5-55.4) in the BTS group (P = 0.0633). However, the median treatment speed was significantly faster with FlushKnife-BTS when the resection size was larger than 1000 m(2) (n = 4, median 24.2 mm(2)/min, range 19.6-27.7 vs n = 4, median 47.4 mm(2)/min, range 44.2-55.4, P = 0.0209). The frequency of knife replacement was less in the BTS group (median 1.76 times in one hour, range 0-5.45) than in the BT group (7.02 times in one hour, range 4.23-15) (P = 0.0065). Our results indicate that FlushKnife-BTS enhances the performance of ESD, particularly for large lesions, by improving air and fluid aspiration and knife insertion during ESD and reducing the frequency of

  2. Single-incision laparoscopic total colectomy.

    PubMed

    Paranjape, Charudutt; Ojo, Oluwatosin J; Carne, David; Guyton, Daniel

    2012-01-01

    To present our experience with a single-incision laparoscopic total colectomy, along with a literature review of all published cases on single-incision laparoscopic total colectomy. A total of 22 cases were published between 2010 and 2011, with our patient being case 23. These procedures were performed in the United States and United Kingdom. Surgical procedures included total colectomy with end ileostomy, proctocolectomy with ileorectal anastomosis, and total proctocolectomy with ileopouch-anal anastomosis. Intraoperative and postoperative data are analyzed. Twenty-two of the 23 cases were performed for benign cases including Crohns, ulcerative colitis, and familial adenomatous polyposis. One case was performed for adenocarcinoma of the cecum. The mean age was 35.3 years (range, 13 to 64), the mean body mass index was 20.1 (range, 19 to 25), mean operative time was 175.9 minutes (range, 139 to 216), mean blood loss was 95.3mL (range, 59 to 200), mean incision length was 2.61cm (range, 2 to 3). Average follow-up was 4.6 months with 2 reported complications. Single-incision laparoscopic total colectomy is feasible and safe in the hands of an experienced surgeon. It has been performed for both benign and malignant cases. It is comparable to the conventional multi-port laparoscopic total colectomy.

  3. Single-Incision Laparoscopic Total Colectomy

    PubMed Central

    Ojo, Oluwatosin J.; Carne, David; Guyton, Daniel

    2012-01-01

    Background and Objectives: To present our experience with a single-incision laparoscopic total colectomy, along with a literature review of all published cases on single-incision laparoscopic total colectomy. Methods: A total of 22 cases were published between 2010 and 2011, with our patient being case 23. These procedures were performed in the United States and United Kingdom. Surgical procedures included total colectomy with end ileostomy, proctocolectomy with ileorectal anastomosis, and total proctocolectomy with ileopouch-anal anastomosis. Intraoperative and postoperative data are analyzed. Results: Twenty-two of the 23 cases were performed for benign cases including Crohns, ulcerative colitis, and familial adenomatous polyposis. One case was performed for adenocarcinoma of the cecum. The mean age was 35.3 years (range, 13 to 64), the mean body mass index was 20.1 (range, 19 to 25), mean operative time was 175.9 minutes (range, 139 to 216), mean blood loss was 95.3mL (range, 59 to 200), mean incision length was 2.61cm (range, 2 to 3). Average follow-up was 4.6 months with 2 reported complications. Conclusions: Single-incision laparoscopic total colectomy is feasible and safe in the hands of an experienced surgeon. It has been performed for both benign and malignant cases. It is comparable to the conventional multi-port laparoscopic total colectomy. PMID:22906326

  4. Penetration tests to study the mechanical tribological properties of chisel type knife

    NASA Astrophysics Data System (ADS)

    Vlăduţoiu, L.; Chişiu, G.; Andrei, T.; Predescu, A.; Muraru, C.; Vlăduţ, V.

    2017-02-01

    The goal of this study was to analyze the behaviour of chisel knife type penetration in a certain type of sand. A series of penetration tests were carried out with chisel knife type, the answer to penetration depending mainly on nature, shape, size of knife and operating parameters such as speed, depth and working conditions. Tests were conducted in work conditions with wet sand and dry sand and determined force of resistance to penetration of the chisel knife type to a certain depth.

  5. Transconjunctival single-plane sclerocorneal incisions versus clear corneal incisions in cataract surgery.

    PubMed

    Sugai, Shigeru; Yoshitomi, Fumiaki; Oshika, Tetsuro

    2010-09-01

    To compare a transconjunctival single-plane sclerocorneal incision with 2 tiny conjunctival cuts at both ends and a clear corneal incision (CCI) in cataract surgery. Department of Ophthalmology, Institute of Clinical Medicine, University of Tsukuba, Ibaraki, Japan. Patients having routine cataract surgery were randomly divided into 2 groups based on incision type; that is, transconjunctival single-plane sclerocorneal or CCI. The incidence of intraoperative ballooning of the conjunctiva (chemosis) and the percentage of eyes that required stromal hydration to securely close the wound in each group were recorded and compared. Each group comprised 61 eyes (61 patients). No eye in the transconjunctival sclerocorneal group and 6 eyes (9.8%) in the CCI group developed intraoperative conjunctival chemosis (P = .027, Fisher exact probability test). Corneal stromal hydration was required in 2 eyes (3.3%) and 15 eyes (24.6%), respectively (P = .001). The transconjunctival single-plane sclerocorneal incision was effective and combined the merits of CCI incisions and sclerocorneal incisions. Copyright (c) 2010 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  6. Gamma Knife Treatment of Brainstem Metastases

    PubMed Central

    Peterson, Halloran E.; Larson, Erik W.; Fairbanks, Robert K.; MacKay, Alexander R.; Lamoreaux, Wayne T.; Call, Jason A.; Carlson, Jonathan D.; Ling, Benjamin C.; Demakas, John J.; Cooke, Barton S.; Peressini, Ben; Lee, Christopher M.

    2014-01-01

    The management of brainstem metastases is challenging. Surgical treatment is usually not an option, and chemotherapy is of limited utility. Stereotactic radiosurgery has emerged as a promising palliative treatment modality in these cases. The goal of this study is to assess our single institution experience treating brainstem metastases with Gamma Knife radiosurgery (GKRS). This retrospective chart review studied 41 patients with brainstem metastases treated with GKRS. The most common primary tumors were lung, breast, renal cell carcinoma, and melanoma. Median age at initial treatment was 59 years. Nineteen (46%) of the patients received whole brain radiation therapy (WBRT) prior to or concurrent with GKRS treatment. Thirty (73%) of the patients had a single brainstem metastasis. The average GKRS dose was 17 Gy. Post-GKRS overall survival at six months was 42%, at 12 months was 22%, and at 24 months was 13%. Local tumor control was achieved in 91% of patients, and there was one patient who had a fatal brain hemorrhage after treatment. Karnofsky performance score (KPS) >80 and the absence of prior WBRT were predictors for improved survival on multivariate analysis (HR 0.60 (p = 0.02), and HR 0.28 (p = 0.02), respectively). GKRS was an effective treatment for brainstem metastases, with excellent local tumor control. PMID:24886816

  7. Results of Gamma Knife Radiosurgery in Acromegaly

    PubMed Central

    Franzin, Alberto; Spatola, Giorgio; Losa, Marco; Picozzi, Piero; Mortini, Pietro

    2012-01-01

    Objective. Single-session radiosurgery with Gamma Knife (GK) may be a potential adjuvant treatment in acromegaly. We analyzed the safety and efficacy of GK in patients who had previously received maximal surgical debulking at our hospital. Methods. The study was a retrospective analysis of hormonal, radiological, and ophthalmologic data collected in a predefined protocol from 1994 to 2009. The mean age at treatment was 42.3 years (range 22–67 yy). 103 acromegalic patients participated in the study. The median follow-up was 71 months (IQ range 43–107). All patients were treated with GK for residual or recurrent GH-secreting adenoma. Results. Sixty-three patients (61.2%) reached the main outcome of the study. The rate of remission was 58.3% at 5 years (95% CI 47.6–69.0%). Other 15 patients (14.6%) were in remission after GK while on treatment with somatostatin analogues. No serious side effects occurred after GK. Eight patients (7.8%) experienced a new deficit of pituitary function. New cases of hypogonadism, hypothyroidism, and hypoadrenalism occurred in 4 of 77 patients (5.2%), 3 of 95 patients (3.2%), and 6 of 100 patients at risk (6.0%), respectively. Conclusion. In a highly selected group of acromegalic patients, GK treatment had good efficacy and safety. PMID:22518119

  8. Gamma Knife radiosurgery for intracranial hemangioblastoma.

    PubMed

    Silva, Danilo; Grabowski, Mathew M; Juthani, Rupa; Sharma, Mayur; Angelov, Lilyana; Vogelbaum, Michael A; Chao, Samuel; Suh, John; Mohammadi, Alireza; Barnett, Gene H

    2016-09-01

    Gamma knife radiosurgery (GKRS) has become a treatment option for intracranial hemangioblastomas, especially in patients with poor clinical status and also high-risk surgical candidates. The objective of this study was to analyze clinical outcome and tumor control rates. Retrospective chart review revealed 12 patients with a total of 20 intracranial hemangioblastomas treated with GKRS from May 1998 until December 2014. Kaplan-Meier plots were used to calculate the actuarial local tumor control rates and rate of recurrence following GKRS. Univariate analysis, including log rank test and Wilcoxon test were used on the Kaplan-Meier plots to evaluate the predictors of tumor progression. Two-tailed p value of <0.05 was considered as significant. Median follow-up was 64months (2-184). Median tumor volume pre-GKRS was 946mm(3) (79-15970), while median tumor volume post-GKRS was 356mm(3) (30-5404). Complications were seen in two patients. Tumor control rates were 100% at 1year, 90% at 3years, and 85% at 5years, using the Kaplan-Meier method. There were no statistically significant univariate predictors of progression identified, although there was a trend towards successful tumor control in solid tumors (p=0.07). GKRS is an effective and safe option for treating intracranial hemangioblastoma with favorable tumor control rates. Copyright © 2016 Elsevier Ltd. All rights reserved.

  9. Gamma knife radiosurgery in movement disorders: Indications and limitations.

    PubMed

    Higuchi, Yoshinori; Matsuda, Shinji; Serizawa, Toru

    2017-01-01

    Functional radiosurgery has advanced steadily during the past half century since the development of the gamma knife technique for treating intractable cancer pain. Applications of radiosurgery for intracranial diseases have increased with a focus on understanding radiobiology. Currently, the use of gamma knife radiosurgery to ablate deep brain structures is not widespread because visualization of the functional targets remains difficult despite the increased availability of advanced neuroimaging technology. Moreover, most existing reports have a small sample size or are retrospective. However, increased experience with intraoperative neurophysiological evaluations in radiofrequency thalamotomy and deep brain stimulation supports anatomical and neurophysiological approaches to the ventralis intermedius nucleus. Two recent prospective studies have promoted the clinical application of functional radiosurgery for movement disorders. For example, unilateral gamma knife thalamotomy is a potential alternative to radiofrequency thalamotomy and deep brain stimulation techniques for intractable tremor patients with contraindications for surgery. Despite the promising efficacy of gamma knife thalamotomy, however, these studies did not include sufficient follow-up to confirm long-term effects. Herein, we review the radiobiology literature, various techniques, and the treatment efficacy of gamma knife radiosurgery for patients with movement disorders. Future research should focus on randomized controlled studies and long-term effects. © 2016 International Parkinson and Movement Disorder Society. © 2016 International Parkinson and Movement Disorder Society.

  10. Surgery or gamma -knife for the treatment of arteriovenous malformations?

    PubMed

    Shigeno, T; Atsuchi, M; Tanaka, J; Goto, K; Ogata, N

    2000-09-01

    Decision making for either surgery or gamma-knife for the treatment of arteriovenous malformations (AVMs) cannot be uniform. The skill of the neurosurgeon in operating on AVMs is now being compared with that of the gamma-knife. The decision varies from case to case and is to be taken by the neurosurgeon. This report presents three cases in which such decision making was not easy. Case 1 was a non-ruptured cingulate AVM of 2.5 cm diameter in the cingulate cortex. The operative field was anticipated to be very narrow between the parietal bridging veins. Case 2 was a tiny ruptured AVM in the speech-motor area which was buried underneath the cortex. Case 3 was a large ruptured thalamo-stiriate-capsular AVM with feeders from the anterior and posterior choroidal arteries. All cases were operated without serious morbidity. A combination of pre-operative intravascular surgery (cases 1 and 3) or postoperative gamma-knife (case 3) was adopted. In conclusion, there is no unitary rule to decide on surgery or gamma-knife for the treatment of AVMs. It depends on what good or harm the responsible surgeon or the gamma-knife does.

  11. Longitudinal incision in surgical release of De Quervain disease.

    PubMed

    Gundes, Hakan; Tosun, Bilgehan

    2005-09-01

    The objective of this paper is to contrast the use of a longitudinal incision in surgical decompression of De Quervain disease with a transverse incision. The advantages are ease in recognition of compartment variations and superficial branches of radial nerve and prevention of palmar tendon subluxation by permitting a more dorsal release of the compartment sheath. Since 2002, we have used a longitudinal skin incision instead of the classic transverse incision to release the first dorsal compartment.

  12. A retracting wire knife for cutting fiber bundles and making sheet lesions of brain tissue.

    PubMed

    Shibata, M; Russell, I S

    1979-07-01

    A retracting knife which has two cutting wires for the transection of fiber bundles is described. The knife holds the fiber bundles of the stria terminalis between the two cutting wires and transects them by a shearing movement as the wires close. In addition, the feasability of such a knife producing a sheet lesion around the n. caudatus is also described.

  13. Development of an air knife to remove seed coat fragments during lint cleaning

    USDA-ARS?s Scientific Manuscript database

    An air knife is a tool commonly used to blow off debris in a manufacturing line. The knife may also be used to break the attachment force between a lint cleaner saw and a seed coat fragment (SCF) with attached fiber, and remove them. Work continued on evaluating an auxiliary air knife mounted on t...

  14. [Stab injury of the brain by kitchen knife].

    PubMed

    Mashiyama, Shoji; Fukawa, Osamu; Kawase, Makoto; Noshita, Norio; Takada, Shihomi

    2006-05-01

    A 32-year-old male attempted suicide by stabbing his forehead with a kitchen knife, and was sent to our hospital. On admission, he was confused (20-30/JCS), but was able to move his both extremities. Skull X-p, CT scan indicated that the kitchen knife penetrated the frontal bone, reached the cerebrum by way of the frontal sinus. Cerebral angiography was performed, and showed no vascular lesions. Emergent craniotomy was performed and the kitchen knife was removed with minimum movement. Traumatic intracerebral hematoma was removed, and injured frontal sinus, dura mater and frontal bone were repaired. Postoperative course was excellent and he was discharged with the wounds well healded, no neurological deficits on the 17th day after the operation. There are several reported cases of such stab injury. Stab injury of the brain was discussed in the literature.

  15. Delayed bleeding after gamma knife surgery for meningioma.

    PubMed

    Kim, C H; Kim, D G; Paek, S H; Chung, H-T; Choi, Y L; Chi, J G

    2004-07-01

    We report the occurrence of haemorrhage in a meningioma after gamma knife surgery.A 52-year-old woman had undergone gamma knife radiosurgery for a growing meningioma in the left tentorial hiatus three years earlier (A radiation dose of 15 Gy was administered to the margin, with a maximum dose of 30 Gy, Fig. 1a). The size of the mass decreased steadily, and central lucency was seen in the follow-up magnetic resonance images, a usual finding seen after gamma knife surgery (MRI, Fig. 1b). However, a MRI taken at the 30-month follow-up showed the tumour to be swollen, and peritumoural oedema had increased (Fig. 1c). Three years later, apoplectic symptoms occurred, and computed tomography revealed a peritumoural haemorrhage, with oedema (Fig. 1d). An emergency craniotomy was carried out, and the biopsy showed a transitional type of meningioma, with vasculopathy and necrosis. After operation she had a right hemiparesis and a visual defect.

  16. Neck incision planning for total laryngectomy: A finite element analysis.

    PubMed

    Feng, Allen L; Clark, James H; Agrawal, Nishant; Moussa, Walied; Richmon, Jeremy D

    2015-11-26

    Post-operative complications can be attributed to technical aspects of surgery, yet no studies have investigated the mechanics behind commonly used incisions for total laryngopharyngectomies (TLP). This procedure, seen in head and neck cancer patients, necessitates free tissue transfer to construct a neo-pharynx, creating an inherently greater risk of complications. We sought to investigate the impact of neck incision location on these post-operative complications for TLP using finite element analysis (FEA). A nonlinear hyperelastic 2-D finite element model was used to evaluate the stress and strain along the incision line of two separate neck incision models commonly used for TLP: low-neck apron (LNA) incisions that incorporate the patient׳s tracheostoma and mid-neck apron (MNA) incisions that do not communicate with the tracheostoma. A constant displacement was applied to the incision to simulate normal neck extension experienced during the post-operative phase. Each neck incision was also modeled at varying strain energy densities to simulate various stages of wound healing. For a constant displacement of 40mm, the principal von Mises stress of the LNA incision varied between 5.87 and 6.41MPa, depending on the hyperelastic properties of the healing incision. This stress was concentrated at the junction of the incision and the fixed tracheostomal edge. The MNA model demonstrated a principal von Mises stress that varied between 0.558 and 0.711MPa and was concentrated along the midline of the neck incision. MNA incisions for TL patients result in principal von Mises stresses which are up to 11 times lower than those seen in LNA incisions. These results coincided with clinical observations from a concurrent study that showed a decrease in rate of wound dehiscence for patients undergoing TLP with an MNA incision.

  17. Drainage basins and channel incision on Mars.

    PubMed

    Aharonson, Oded; Zuber, Maria T; Rothman, Daniel H; Schorghofer, Norbert; Whipple, Kelin X

    2002-02-19

    Measurements acquired by the Mars Orbiter Laser Altimeter on board the Mars Global Surveyor indicate that large drainage systems on Mars have geomorphic characteristics inconsistent with prolonged erosion by surface runoff. We find the topography has not evolved to an expected equilibrium terrain form, even in areas where runoff incision has been previously interpreted. By analogy with terrestrial examples, groundwater sapping may have played an important role in the incision. Longitudinally flat floor segments may provide a direct indication of lithologic layers in the bedrock, altering subsurface hydrology. However, it is unlikely that floor levels are entirely due to inherited structures due to their planar cross-cutting relations. These conclusions are based on previously unavailable observations, including extensive piece-wise linear longitudinal profiles, frequent knickpoints, hanging valleys, and small basin concavity exponents.

  18. [Submammary skin incision for longitudinal medial sternotomy].

    PubMed

    Ramírez Marroquín, S; Rojas Pacheco, A M; Herrera Alarcón, V; Santibáñez Escobar, F; Molina Méndez, J; Serrano Gallardo, G; Barragán García, R

    1996-01-01

    The submammary incision has been postulated as an alternative in median sternotomy approach since 1960. We used this incision in 32 females patients from 1 to 24 years. The diagnoses were atrial septal defects (ASD) 23 patients, ventricular septal defect (VSD) 2 patients, double outlet right ventricle 1 patient, supravalvular aortic stenosis 1 patient, ASD with VSD 3 patients and partial anomalous pulmonary venous connection 1 patient. Nine patients had a complication: cheloid scar 1 patient, seroma 2 patients, wound dehiscence 3 patients, and diminution of sensitivity 3 patients. We conclude, that this type of surgical approach is an excellent alternative for women with good aesthetic and psychological results. Their complications are easy to correct.

  19. A randomized comparative study on modified Joel-Cohen incision versus Pfannenstiel incision for cesarean section

    PubMed Central

    Saha, Shyama Prasad; Bhattarcharjee, Nabendu; Das Mahanta, Sabysachi; Naskar, Animesh; Bhattacharyya, Sanjoy Kumar

    2013-01-01

    Objective: Pfanennstiel incision is the most commonly used incision for cesarean section, but may not be the best. This study compared the modified Joel-Cohen incision with the Pfannenstiel incision to evaluate whether techniques to open the abdomen might influence operative time, and maternal and neonatal outcomes. Material and Methods: In a randomized comparative trial, 302 women with gestational age >34 weeks, requiring cesarean section, were randomly assigned to either modified Joel-Cohen incision or Pfannenstiel incision for entry into the peritoneal cavity. The primary outcome measure was total time required for performing operation and secondary outcome measures were baby extraction time, number of haemostatic procedures used in the abdominal wall, postoperative morbidity, postoperative hospital stay and neonatal outcome. Results: Mean total operative time was significantly less in the modified Joel-Cohen group as compared to the Pfannenstiel group (29.81 vs 32.67 min, p<0.0001, 95%CI=2.253 to 3.467). Time taken to deliver the baby and haemostatic procedures required during operation were also significantly less in the modified Joel-Cohen group as compared to the Pfannenstiel group. Requirement of strong analgesics was higher in the Pfannenstiel group (53.64% vs 21.85%, p<0.0001). There was no statically significant difference in the incidence of postoperative wound complications but postoperative stay in hospital was significantly less in the modified Joel-Cohen group (p=0.002). Neonatal outcomes were similar in both groups. Conclusion: The modified Joel-Cohen incision for entry into peritoneal cavity during cesarean section is associated with reduced mean total operative and baby extraction times with less postoperative pain and shorter hospital stay, which may be beneficial and cost effective. PMID:24592067

  20. Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie's disease with erectile dysfunction.

    PubMed

    Djordjevic, Miroslav L; Kojovic, Vladimir

    2013-05-01

    We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie's disease associated with erectile dysfunction. Between April 2005 and June 2011, 62 patients underwent surgery due to severe Peyronie's disease associated with erectile dysfunction. Malleable and inflatable penile prostheses were inserted in 49 and 13 cases, respectively. Penile prostheses were inserted into the corpora cavernosa using the standard ventral approach. After lifting the neurovascular bundle, the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis. Subsequently, the wide neurovascular bundle was replaced, and all incisions of the tunica albuginea were covered to prevent corporal grafting. In the median follow-up of 35 months (range 14-82 months), the penis was completely straightened in 59 (95%) patients. Numbness of the glans, which the patients found initially upsetting, decreased or disappeared spontaneously 3-6 months later. Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie's disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea without additional grafting.

  1. Penile prosthesis implantation and tunica albuginea incision without grafting in the treatment of Peyronie's disease with erectile dysfunction

    PubMed Central

    Djordjevic, Miroslav L; Kojovic, Vladimir

    2013-01-01

    We evaluated penile prosthesis implantation with tunica albuginea-relaxing incisions without grafting in the treatment of Peyronie's disease associated with erectile dysfunction. Between April 2005 and June 2011, 62 patients underwent surgery due to severe Peyronie's disease associated with erectile dysfunction. Malleable and inflatable penile prostheses were inserted in 49 and 13 cases, respectively. Penile prostheses were inserted into the corpora cavernosa using the standard ventral approach. After lifting the neurovascular bundle, the tunica albuginea was incised and opened at the plaque region to correct the deformities and to lengthen the penis. Subsequently, the wide neurovascular bundle was replaced, and all incisions of the tunica albuginea were covered to prevent corporal grafting. In the median follow-up of 35 months (range 14–82 months), the penis was completely straightened in 59 (95%) patients. Numbness of the glans, which the patients found initially upsetting, decreased or disappeared spontaneously 3–6 months later. Penile prosthesis implantation with tunica albuginea incisions is a viable alternative in the treatment of Peyronie's disease because the extensive dissection of the neurovascular bundle allows a good approach to the plaque and provides excellent covering of the incised tunica albuginea without additional grafting. PMID:23435473

  2. Leiomyomatous hamartoma of the incisive papilla.

    PubMed

    Corrêa, L; Lotufo, M; Martins, M T; Sugaya, N; de Sousa, S C

    2001-01-01

    A case of unusual hamartoma in a six-year-old otherwise healthy Brazilian girl is reported, with emphasis on histological and immunohistochemical features. A mass observed in the incisive papilla was detected whose appearance was similar to congenital epulis or fibroma. Histological findings showed interlacing fascicles of large spindle cells resembling smooth muscle cells. Immunohistochemical staining for desmin and for smooth-muscle actin was positive. The histological diagnosis was leiomyomatous hamartoma, based on clinical and microscopic observations.

  3. Single incision endoscopic surgery for gynaecomastia.

    PubMed

    Jarrar, G; Peel, A; Fahmy, R; Deol, H; Salih, V; Mostafa, A

    2011-09-01

    Surgical excision has been an effective treatment for gynaecomastia. Recently, there has been a shift from the open approach to minimally invasive techniques. In this report we describe our technique which includes endoscopic excision and/or liposuction of gynaecomastia via a single lateral chest wall incision. Between May 2007 and April 2010, a total of 12 gynaecomastia patients were treated with liposuction and/or endoscopic excision. Patients were divided into 3 groups: group I; liposuction only, group II; endoscopic excision plus liposuction and group III; endoscopic excision only. One 15 mm incision was made laterally at the anterior axillary line. A vacuum assisted liposuction removing the fatty tissue was performed. Then endoscopic excision of the remaining fibroglandular tissue was done under vision through the same incision. The parynchyma was then dissected into small pieces and pulled out. Group I had liposuction only (n = 4), group II had liposuction combined with endoscopic excision (n = 7) (58%) while group III had endoscopic excision only (n = 1). The mean operative time for liposuction and endoscopic excision was 58 min for each side. Mean hospital stay was 1.4 days. Postoperative complications included infection with abscess formation and one patient had seroma. Mean follow-up was 56 weeks. Eleven out of twelve patients (92%) were satisfied with their results. Long-term follow-up showed that results were stable over time, and no revisions were necessary. Endoscopic excision of gynaecomastia through a single lateral chest wall incision is a minimally invasive effective and safe technique for the management of gynaecomastia, with excellent aesthetic results and an acceptable complication rate. Copyright © 2011 British Association of Plastic, Reconstructive and Aesthetic Surgeons. Published by Elsevier Ltd. All rights reserved.

  4. [Unique incision vasectomy: review of 1,800 cases].

    PubMed

    Castillo Jimeno, J M; Santiago González, A; Rodríguez Pérez, M J; Quel Alzueta, N; Ruiz Rubio, J L; Antón López, M J; Martínez Morillas, M

    1992-01-01

    We reviewed 1,800 vasectomy procedures using the double lateral scrotal incision and single incision of the raphe that had been performed at the Family Planning Center. The number of complications were minimal for both techniques: 6.5% for the patients submitted to the double incision and 5.5% for those submitted to the single incision procedure. The advantages of the single incision procedure are: it is easy to perform, less anesthesia is required, there are less complications, and the operating time is reduced.

  5. Minimally invasive "pocket incision" aortic valve surgery.

    PubMed

    Yakub, M A; Pau, K K; Awang, Y

    1999-02-01

    A minimally invasive approach to aortic valve surgery through a transverse incision ("pocket incision") at the right second intercostal space was examined. Sixteen patients with a mean age of 30 years underwent this approach. The third costal cartilage was either excised (n = 5) or dislocated (n = 11). The right internal mammary artery was preserved. Cardiopulmonary bypass (CPB) was established with aortic-right atrial cannulation in all except the first case. Aortic valve replacements (AVR) were performed in 15 patients and one had aortic valve repair with concomitant ventricular septal defect closure. There was no mortality and no major complications. The aortic cross-clamp, CPB and operative times were 72 +/- 19 mins, 105 +/- 26 mins and 3 hrs 00 min +/- 29 mins respectively. The mean time to extubation was 5.7 +/- 4.0 hrs, ICU stay of 27 +/- 9 hrs and postoperative hospital stay of 5.1 +/- 1.2 days. Minimally invasive "pocket incision" aortic valve surgery is technically feasible and safe. It has the advantages of central cannulation for CPB, preservation of the internal mammary artery and avoiding sternotomy. This approach is cosmetically acceptable and allows rapid patient recovery.

  6. Orbitoethmoidal impacted injury by kitchen knife causing abducens nerve palsy.

    PubMed

    Carneiro, José Thiers; da Silva Tabosa, Ana Karla; de Souza, Fernando Jordão; Shinohara, Elio Hitoshi

    2011-06-01

    Impacted knife injuries in the maxillofacial region are rare and infrequently reported. In cases of injury involving orbit or eye, these reports are even rarer. Damage to the orbital contents may result in a rupture of the globe, extraocular muscle injury, lacrimal gland damage, and others. Orbital foreign bodies are not only difficult to detect, and clinical features vary according to its size, characteristics, shape, penetrating method, and site. In this report, a case of abducens nerve palsy after orbitoethmoidal knife injury is presented.

  7. A phase-knife wave-front sensor

    SciTech Connect

    Goncharov, A S; Larichev, A V

    2005-01-31

    The use of an optical system with a phase knife is proposed to record qualitatively the shape of the optical-radiation wave front. Theoretical and numerical studies of a sensor based on a phase knife are performed, the algorithms for reconstruction of the phase function and schemes for sensor realisation are developed, and the range in which the device can be used expediently is determined. The sensor component parameters required for its realisation are determined, and the sensor efficiency in various operational modes is tested experimentally. (laser applications and other topics in quantum electronics)

  8. Repeat Gamma Knife surgery for vestibular schwannomas

    PubMed Central

    Lonneville, Sarah; Delbrouck, Carine; Renier, Cécile; Devriendt, Daniel; Massager, Nicolas

    2015-01-01

    Background: Gamma Knife (GK) surgery is a recognized treatment option for the management of small to medium-sized vestibular schwannoma (VS) associated with high-tumor control and low morbidity. When a radiosurgical treatment fails to stop tumor growth, repeat GK surgery can be proposed in selected cases. Methods: A series of 27 GK retreatments was performed in 25 patients with VS; 2 patients underwent three procedures. The median time interval between GK treatments was 45 months. The median margin dose used for the first, second, and third GK treatments was 12 Gy, 12 Gy, and 14 Gy, respectively. Six patients (4 patients for the second irradiation and 2 patients for the third irradiation) with partial tumor regrowth were treated only on the growing part of the tumor using a median margin dose of 13 Gy. The median tumor volume was 0.9, 2.3, and 0.7 cc for the first, second, and third treatments, respectively. Stereotactic positron emission tomography (PET) guidance was used for dose planning in 6 cases. Results: Mean follow-up duration was 46 months (range 24–110). At the last follow-up, 85% of schwannomas were controlled. The tumor volume decreased, remained unchanged, or increased after retreatment in 15, 8, and 4 cases, respectively. Four patients had PET during follow-up, and all showed a significant metabolic decrease of the tumor. Hearing was not preserved after retreatment in any patients. New facial or trigeminal palsy did not occur after retreatment. Conclusions: Our results support the long-term efficacy and low morbidity of repeat GK treatment for selected patients with tumor growth after initial treatment. PMID:26500799

  9. Repeat Gamma Knife Radiosurgery for Trigeminal Neuralgia

    SciTech Connect

    Aubuchon, Adam C.; Chan, Michael D.; Lovato, James F.; Balamucki, Christopher J.; Ellis, Thomas L.; Tatter, Stephen B.; McMullen, Kevin P.; Munley, Michael T.; Deguzman, Allan F.; Ekstrand, Kenneth E.; Bourland, J. Daniel; Shaw, Edward G.

    2011-11-15

    Purpose: Repeat gamma knife stereotactic radiosurgery (GKRS) for recurrent or persistent trigeminal neuralgia induces an additional response but at the expense of an increased incidence of facial numbness. The present series summarized the results of a repeat treatment series at Wake Forest University Baptist Medical Center, including a multivariate analysis of the data to identify the prognostic factors for treatment success and toxicity. Methods and Materials: Between January 1999 and December 2007, 37 patients underwent a second GKRS application because of treatment failure after a first GKRS treatment. The mean initial dose in the series was 87.3 Gy (range, 80-90). The mean retreatment dose was 84.4 Gy (range, 60-90). The dosimetric variables recorded included the dorsal root entry zone dose, pons surface dose, and dose to the distal nerve. Results: Of the 37 patients, 81% achieved a >50% pain relief response to repeat GKRS, and 57% experienced some form of trigeminal dysfunction after repeat GKRS. Two patients (5%) experienced clinically significant toxicity: one with bothersome numbness and one with corneal dryness requiring tarsorraphy. A dorsal root entry zone dose at repeat treatment of >26.6 Gy predicted for treatment success (61% vs. 32%, p = .0716). A cumulative dorsal root entry zone dose of >84.3 Gy (72% vs. 44%, p = .091) and a cumulative pons surface dose of >108.5 Gy (78% vs. 44%, p = .018) predicted for post-GKRS numbness. The presence of any post-GKRS numbness predicted for a >50% decrease in pain intensity (100% vs. 60%, p = .0015). Conclusion: Repeat GKRS is a viable treatment option for recurrent trigeminal neuralgia, although the patient assumes a greater risk of nerve dysfunction to achieve maximal pain relief.

  10. The assessment of cold hyperalgesia after an incision.

    PubMed

    Scherer, Moritz; Reichl, Sylvia U; Augustin, Miriam; Pogatzki-Zahn, Esther M; Zahn, Peter K

    2010-01-01

    Although cold hypersensitivity is a well-documented phenomenon in animals and humans with inflammatory and neuropathic pain, little is known about the presence of cold hyperalgesia after surgery. Therefore, we studied primary cold hyperalgesia after a surgical incision in mice. Before and after plantar incision, inflammation with complete Freund adjuvant, and spared nerve ligation, unrestrained male animals were placed on a Peltier-cooled cold plate with a surface temperature of 0 degrees C and withdrawal latencies were measured. Additionally, incision-induced cold hyperalgesia was also assessed in female animals. Furthermore, skin temperature before and after plantar incision and inflammation were assessed by using infrared thermography (Varioscan LW 3011; Infratec, Dresden, Germany). Cold hyperalgesia to a noxious cold stimulus was observed after inflammation and nerve injury but not after a surgical incision. Similar results were demonstrated for female animals after incision. Furthermore, a significant increase in skin temperature was recorded after inflammation but not after incision, indicating that a surgery evokes only minor inflammatory effects. The present data give strong evidence that a surgical incision does not cause cold hyperalgesia. Furthermore, a lack of cold hyperalgesia in unrestrained male and female mice after incision was not due to increased skin temperature after incision. Finally, we demonstrated that in contrast to a surgical incision, inflammation and nerve injury generate intense cold hyperalgesia and an increase in skin temperature, suggesting that different mechanisms are involved in surgical and inflammatory or neuropathic pain.

  11. Gamma Knife Radiosurgery in Sphenopetroclival Meningiomas: Preliminary Experience at the Iran Gamma Knife Center.

    PubMed

    Azar, Maziar; Kazemi, Farid; Chanideh, Iran; Amirjamshidi, Abbas; Amini, Elahe; Ghanavati, Pedram

    2016-09-01

    The aims of this study were to characterize the epidemiologic, histologic, and radiologic aspects of sphenopetroclival meningiomas (SpPCMs) and to evaluate the outcome of Gamma Knife radiosurgery (GKRS) either as an adjunct to microsurgery or as a primary SpPCM treatment modality. In this retrospective study, medical records of patients with SpPCM who underwent GKRS at the Iran Gamma Knife Center between April 2003 and March 2012 were analyzed. We assessed 122 patients with SpPCMs, including 101 women and 21 men, aged 24-94 years. The mean tumor volume was 12.24 ± 9.30 mL. Patients received 22.32 ± 3.29 Gy and 13.18 ± 1.02 Gy maximal and average marginal dose of GKRS, respectively. The most common complaint was visual impairment, followed by facial sensory impairment and headache. The most frequently involved cranial nerves were III, IV, and VI in 72.1% of patients, followed by II in 52.9%, and V in 35.5%. After radiosurgery, headaches improved in 90.0%, diplopia in 75.0%, and ptosis in 63.0% of patients. On magnetic resonance imaging, tumor size was reduced, unchanged, or increased in 77, 44, and 1 patient, respectively. Progression-free survival at the 5-year follow-up was 56.6%. Younger age (hazard ratio = 0.972, P = 0.011) and lower tumor volume (hazard ratio = 0.959, P = 0.009) were the main prognostic factors for progression-free survival. GKRS can be an effective alternative treatment for controlling the progression of SpPCM tumors, producing appropriate clinical outcomes and few complications. Copyright © 2016 Elsevier Inc. All rights reserved.

  12. Feasibility of identification of gamma knife planning strategies by identification of pareto optimal gamma knife plans.

    PubMed

    Giller, C A

    2011-12-01

    The use of conformity indices to optimize Gamma Knife planning is common, but does not address important tradeoffs between dose to tumor and normal tissue. Pareto analysis has been used for this purpose in other applications, but not for Gamma Knife (GK) planning. The goal of this work is to use computer models to show that Pareto analysis may be feasible for GK planning to identify dosimetric tradeoffs. We define a GK plan A to be Pareto dominant to B if the prescription isodose volume of A covers more tumor but not more normal tissue than B, or if A covers less normal tissue but not less tumor than B. A plan is Pareto optimal if it is not dominated by any other plan. Two different Pareto optimal plans represent different tradeoffs between dose to tumor and normal tissue, because neither plan dominates the other. 'GK simulator' software calculated dose distributions for GK plans, and was called repetitively by a genetic algorithm to calculate Pareto dominant plans. Three irregular tumor shapes were tested in 17 trials using various combinations of shots. The mean number of Pareto dominant plans/trial was 59 ± 17 (sd). Different planning strategies were identified by large differences in shot positions, and 70 of the 153 coordinate plots (46%) showed differences of 5mm or more. The Pareto dominant plans dominated other nearby plans. Pareto dominant plans represent different dosimetric tradeoffs and can be systematically calculated using genetic algorithms. Automatic identification of non-intuitive planning strategies may be feasible with these methods.

  13. Latent Period of Relaxation.

    PubMed

    Kobayashi, M; Irisawa, H

    1961-10-27

    The latent period of relaxation of molluscan myocardium due to anodal current is much longer than that of contraction. Although the rate and the grade of relaxation are intimately related to both the stimulus condition and the muscle tension, the latent period of relaxation remains constant, except when the temperature of the bathing fluid is changed.

  14. Risk management in a community Gamma Knife unit.

    PubMed

    Johnstone, P A; Hodgens, D W; Ott, K; Goetsch, S J

    2001-01-01

    The records of the San Diego Gamma Knife Center were retrospectively reviewed for unprogrammed events as part of a risk management assessment. Review was made of the physicist notes of the first 1,000 patients successfully treated at the center. This encompassed 1,020 stereotactic frame placement procedures, accompanied by Gamma Knife radiosurgery in 98.0% of intended cases. A total of 7,145 Gamma Knife shots were delivered to 1,509 lesions. Of the 43 unprogrammed events documented, 8 were patient related and 14 were related to lesion growth or location; these were considered unavoidable. Further, one event was related to dose administration, 5 to diagnosis, 15 to technique; these were considered potentially avoidable. This yielded an avoidable error rate of 2.1% per patient, 1.4% per lesion treated, and 0.29% per shot. It was clear that more avoidable errors occurred early in the center's operation, consistent with a learning curve. Review of individual physician's cases revealed none appeared more likely to have an avoidable event. Consistently high quality may be achieved at a community-based Gamma Knife center if sufficient multidisciplinary involvement is achieved. Copyright 2002 S. Karger AG, Basel

  15. [Analysis of bleeding cause after uvulopalatopharyngoplasty with endotherm knife].

    PubMed

    Yang, Guoning; Cun, Lihua; Ma, Ya; Duan, Jingyan

    2015-10-01

    To summary and analyze the bleeding causes after uvulopalatopharyngoplasty(UPPP) with endotherm knife, and preventive measures will be given to effectively reduce postoperation hemorrhage. Two hundred and twenty-six cases of obstructive sleep apnea hypopnea syndrome (OSAHS) adult patients, were carryed out UPPP under general anesthesia with endotherm knife to observe postoperation hemorrhage. Eight cases out of 226 patients or 3.5% occurred postoperation hemorrhage, 2 cases after 1 or 2 days, 6 cases after 6 or 12 days. The postoperation hemorrhage stopped by local compression hemostasis or bi-polar coagulation hemostasis, and no more bleeding occurred. The minimal trauma, quick operation and less-bleeding will be caused by UPPP with endotherm knife. Few patients 3.5% had a small amount of bleeding after operation, but no serious bleeding occured. Hemorrhage often happened during pseud mucosa falling off period. The bleeding was related with using skill of endotherm knife during operation, postoperation pse-ud mucosa falling off, local inflammation, improper eating and emotional stress of patients.

  16. "Fist, Stick, Knife, Gun": Getting Real in Upward Bound.

    ERIC Educational Resources Information Center

    Pace, Barbara G.; Adkins, Theresa A.

    2002-01-01

    Describes how a teacher found literature for Upward Bound students. Presents Geoffrey Canada's "Fist, Stick, Knife, Gun: A Personal History of Violence in America" as a nonfiction work to provide clarity and connections that might not have been available in a fictional work, yet it had elements of literary fiction that made the text…

  17. Investigation of waste glass pouring behavior over a knife edge

    SciTech Connect

    Ebadian, M.A.

    1998-01-01

    The development of vitrification technology for converting radioactive waste into a glass solid began in the early 1960s. Some problems encountered in the vitrification process are still waiting for a solution. One of them is wicking. During pouring, the glass stream flows down the wall of the pour spout until it reaches an angled cut in the wall. At this point, the stream is supposed to break cleanly away from the wall of the pour spout and fall freely into the canister. However, the glass stream is often pulled toward the wall and does not always fall into the canister, a phenomenon known as wicking. Phase 1 involves the assembly, construction, and testing of a melter capable of supplying molten glass at operational flow rates over a break-off point knife edge. Phase 2 will evaluate the effects of glass and pour spout temperatures as well as glass flow rates on the glass flow behavior over the knife edge. Phase 3 will identify the effects on wicking resulting from varying the knife edge diameter and height as well as changing the back-cut angle of the knife edge. The following tasks were completed in FY97: Design the experimental system for glass melting and pouring; Acquire and assemble the melter system; and Perform initial research work.

  18. The Shoemaker's Knife--An Approach of the Polya Type.

    ERIC Educational Resources Information Center

    Libeskind, Shlomo; Lott, Johnny W.

    1984-01-01

    Archimedes' shoemaker's knife problem is interesting in its own right and also allows the demonstration of heuristic teaching ideas and a different method of doing a routine construction. The focus in the article is on the thought processes involved and questions asked when attempting proofs with the problem. (MNS)

  19. 40. Main fuses and knife switch for power to the ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    40. Main fuses and knife switch for power to the bridge, located in the control house. This is one of two located at either end of the main electrical panel (photograph 41). Facing east. - Henry Ford Bridge, Spanning Cerritos Channel, Los Angeles-Long Beach Harbor, Los Angeles, Los Angeles County, CA

  20. "Fist, Stick, Knife, Gun": Getting Real in Upward Bound.

    ERIC Educational Resources Information Center

    Pace, Barbara G.; Adkins, Theresa A.

    2002-01-01

    Describes how a teacher found literature for Upward Bound students. Presents Geoffrey Canada's "Fist, Stick, Knife, Gun: A Personal History of Violence in America" as a nonfiction work to provide clarity and connections that might not have been available in a fictional work, yet it had elements of literary fiction that made the text…

  1. Adjustable knife cuts honeycomb material to specified depth

    NASA Technical Reports Server (NTRS)

    Rauschl, J. A.

    1966-01-01

    Calibrated, adjustable knife cuts aluminum honeycomb or other soft materials to a desired depth. The frame of the device accommodates standard commercial blades. Since the blade is always visible to the operator, the device can be used on any straight or irregular layout line.

  2. The Shoemaker's Knife--An Approach of the Polya Type.

    ERIC Educational Resources Information Center

    Libeskind, Shlomo; Lott, Johnny W.

    1984-01-01

    Archimedes' shoemaker's knife problem is interesting in its own right and also allows the demonstration of heuristic teaching ideas and a different method of doing a routine construction. The focus in the article is on the thought processes involved and questions asked when attempting proofs with the problem. (MNS)

  3. Electromagnetic tracker accuracy in the CyberKnife suite

    NASA Astrophysics Data System (ADS)

    Wilson, Emmanuel; Slack, Rebecca; Banovac, Filip; Dieterich, Sonja; Zhang, Hui; Cleary, Kevin

    2006-03-01

    Electromagnetic trackers have found inroads into medical applications as a tool for navigation in recent years. Their susceptibility to interference from both electromagnetic and ferromagnetic sources have prompted several accuracy assessment studies in past years. To the best of our knowledge, this is the first accuracy study conducted to characterize measurement accuracy of an NDI AURORA electromagnetic tracker within a CyberKnife radiosurgery suite. CyberKnife is a frameless, stereotactic radiosurgery device used to ablate tumors within the brain, spine and in recent years, the chest and abdomen. This paper uses a data collection protocol to collect uniformly distributed data points within a subset of the AURORA measurement volume in a CyberKnife suite. The key aim of the study is to determine the extent to which large metal components of the CyberKnife stereotactic radiosurgery device and robot mount contribute to overall system performance for the AURORA electromagnetic device. A secondary goal of the work is to determine the variation in accuracy and device behavior with the presence of ionizing radiation when the LINAC is turned on.

  4. A new Gamma Knife radiosurgery paradigm: Tomosurgery

    NASA Astrophysics Data System (ADS)

    Hu, Xiaoliang

    The Leksell (Elekta, Stockholm, Sweden) Gamma Knife(TM) (LGK) is the worldwide standard-of-care for the radiosurgical treatment of a wide variety of intracranial lesions. The current LGK utilizes a step-and-shoot dose delivery mechanism where the centroid of each conformal radiation dose (i.e., the shot isocenter) requires repositioning the patient outside of the irradiation field. Perhaps the greatest challenge the LGK treatment team faces is planning the treatment of large and/or complexly shaped lesions that may be in close proximity to critical neural or vascular structures. The standard manual treatment planning approach is a time consuming procedure where additional time spent does not guarantee the identification of an increasingly optimal treatment plan. I propose a new radiosurgery paradigm which I refer to as "Tomosurgery". The Tomosurgery paradigm begins with the division of the target volume into a series of adjacent treatment slices, each with a carefully determined optimal thickness. The use of a continuously moving disk-shaped radiation shot that moves through the lesion in a raster-scanning pattern is expected to improve overall radiation dose conformality and homogeneity. The Tomosurgery treatment planning algorithm recruits a two-stage optimization strategy, which first plans each treatment slice as a simplified 2D problem and secondly optimally assembles the 2D treatment plans into the final 3D treatment plan. Tested on 11 clinical LGK cases, the automated inversely-generated Tomosurgery treatment plans performed as well or better than the neurosurgeon's manually created treatment plans across all criteria: (a) dose volume histograms, (b) dose homogeneity, (c) dose conformality, and (d) critical structure damage, where applicable. LGK Tomosurgery inverse treatment planning required much less time than standard of care, manual (i.e., forward) LGK treatment planning procedures. These results suggest that Tomosurgery might provide an improvement

  5. Dosimetry of the Leksell gamma knife

    NASA Astrophysics Data System (ADS)

    Meltsner, Sheridan Griffin

    No accepted official protocol exists for the dosimetry of the Leksell Gamma KnifeRTM (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 separate 60Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This paper proposes an air kerma based dosimetry protocol using an in-air or in-acrylic phantom measurement to determine the dose rate of fields collimated by the 18 mm helmet of a GK unit. A small-volume ionization chamber was used to make measurements at the physical isocenter of three GK units. The dose rate to water was determined using a modified version of the AAPM Task Group 21 protocol designed for use with 60Co-based teletherapy machines. This experimentally determined dose rate was compared to the treatment planning system (TPS) dose rate that is determined by the clinical medical physicist at the time of machine commissioning. The TPS dose rate is defined as dose rate to water at a depth of 8 cm. The dose rate to water for the 18 mm helmet determined using the air kerma based calculations presented here is consistently between 1.5% and 2.9% higher than the TPS dose rate. These air kerma based measurements allow GK dosimetry to be performed with an established dosimetry protocol and without complications arising from the use of and possible variations in solid phantom material. Measurements were made with the same chamber in a spherical acrylic phantom for comparison. This methodology will allow future development of calibration methods appropriate for the smaller fields of GK units to be compared to a well established standard. Multiple three-dimensional dosimetry methods were also used to capture the dose distribution of the entire field of the GK. These methods included radiosensitive gel, a novel three-dimensional radiochromic film phantom, and Monte Carlo modeling. These methods were also compared to the

  6. Minimum-incision metatarsal ray resection: an observational case series.

    PubMed

    Roukis, Thomas S

    2010-01-01

    This report describes the results of 17 metatarsal ray resections performed through a minimal incision in 13 consecutive patients. Each patient underwent minimum-incision metatarsal ray resection for either definitive treatment or as the index incision and drainage procedure followed by transmetatarsal amputation. There were 10 male and 3 female patients with a mean age of 68.8 +/- 8.5 years (range, 59-83 years). Twelve patients had diabetes mellitus and 7 had critical limb ischemia. There were 11 right feet and 6 left feet involved, and 3 second, 3 third, 3 fourth, and 8 fifth minimum-incision metatarsal ray resections performed. Direct primary-incision closure was performed 7 times (1 with adjacent percutaneous metatarsal osteotomy), delayed primary closure was performed 4 times (1 with external fixation), and conversion to a transmetatarsal amputation was performed 2 times. Fourteen of 17 minimum-incision metatarsal ray resections were deemed successful. Two failures occurred when skin necrosis developed from excessive tension along the incision line requiring conversion to a transmetatarsal amputation, and the other occurred in a patient with unreconstructed critical limb ischemia who underwent multiple repeated incision and drainage procedures and vascular bypass with ultimate healing via secondary intent. When properly performed in patients with adequate vascular inflow, minimum-incision metatarsal ray resection as the definitive procedure or in conjunction with an incision and drainage for unsalvageable toe infection or gangrene represents a safe, simple, useful technique.

  7. Knife mill operating factors effect on switchgrass particle size distributions.

    PubMed

    Bitra, Venkata S P; Womac, Alvin R; Yang, Yuechuan T; Igathinathane, C; Miu, Petre I; Chevanan, Nehru; Sokhansanj, Shahab

    2009-11-01

    Biomass particle size impacts handling, storage, conversion, and dust control systems. Switchgrass (Panicum virgatum L.) particle size distributions created by a knife mill were determined for integral classifying screen sizes from 12.7 to 50.8 mm, operating speeds from 250 to 500 rpm, and mass input rates from 2 to 11 kg/min. Particle distributions were classified with standardized sieves for forage analysis that included horizontal sieving motion with machined-aluminum sieves of thickness proportional to sieve opening dimensions. Then, a wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Correlation coefficient of geometric mean length with knife mill screen size, feed rate, and speed were 0.872, 0.349, and 0.037, respectively. Hence, knife mill screen size largely determined particle size of switchgrass chop. Feed rate had an unexpected influence on particle size, though to a lesser degree than screen size. The Rosin-Rammler function fit the chopped switchgrass size distribution data with an R(2)>0.982. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Uniformity coefficient was more than 4.0, which indicated a large assortment of particles and also represented a well-graded particle size distribution. Knife mill chopping of switchgrass produced 'strongly fine skewed mesokurtic' particles with 12.7-25.4 mm screens and 'fine skewed mesokurtic' particles with 50.8 mm screen. Results of this extensive analysis of particle sizes can be applied to selection of knife mill operating parameters to produce a particular size of switchgrass chop, and will serve as a guide for relations among the various analytic descriptors of biomass particle distributions.

  8. Knife mill operating factors effect on switchgrass particle size distributions

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Yang, Y.T.; Igathinathane, C.; Miu, P.I; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-06-01

    Biomass particle size impacts handling, storage, conversion, and dust control systems. Switchgrass (Panicum virgatum L.) particle size distributions created by a knife mill were determined for integral classifying screen sizes from 12.7 to 50.8 mm, operating speeds from 250 to 500 rpm, and mass input rates from 2 to 11 kg/min. Particle distributions were classified with standardized sieves for forage analysis that included horizontal sieving motion with machined-aluminum sieves of thickness proportional to sieve opening dimensions. Then, a wide range of analytical descriptors were examined to mathematically represent the range of particle sizes in the distributions. Correlation coefficient of geometric mean length with knife mill screen size, feed rate, and speed were 0.872, 0.349, and 0.037, respectively. Hence, knife mill screen size largely determined particle size of switchgrass chop. Feed rate had an unexpected influence on particle size, though to a lesser degree than screen size. The Rosin Rammler function fit the chopped switchgrass size distribution data with an R2 > 0.982. Mass relative span was greater than 1, which indicated a wide distribution of particle sizes. Uniformity coefficient was more than 4.0, which indicated a large assortment of particles and also represented a well-graded particle size distribution. Knife mill chopping of switchgrass produced strongly fine skewed mesokurtic particles with 12.7 25.4 mm screens and fine skewed mesokurtic particles with 50.8 mm screen. Results of this extensive analysis of particle sizes can be applied to selection of knife mill operating parameters to produce a particular size of switchgrass chop, and will serve as a guide for relations among the various analytic descriptors of biomass particle distributions.

  9. CyberKnife radiosurgery for the treatment of orbital metastases.

    PubMed

    Klingenstein, A; Kufeld, M; Wowra, B; Muacevic, A; Fürweger, C; Schaller, U C

    2012-10-01

    Purpose of this study is to evaluate radiographic therapy response, clinical outcome and adverse effects of CyberKnife radiosurgery in patients suffering from orbital metastases. Sixteen orbital metastases originating from different solid cancers in fourteen patients were treated by single fraction CyberKnife radiosurgery. Radiographic response and clinical outcome were evaluated. The treated tumor volume ranged from 0.2 to 35 cm3 (median 2.3 cm3, mean 7.0 cm3, SD 6 10.4 cm3, CI 0.9-9.4 cm3). The prescription dose ranged from 16.5-21 Gy (median 18 Gy, mean 18.2 Gy, SD 6 1.2 Gy, CI 17.0-18.4 Gy). A no change situation was observed in nine lesions, partial remission in four as well as complete remission in one metastasis. Tumor growth was stabilized or regressive following CyberKnife therapy in 87% of the cases. Recurrence was observed in two cases (13%). Before therapy, three patients suffered from visual disturbance and five patients reported diplopia. Six patients had no initial symptoms. After therapy, one patient indicated improvement of the present visual deficit and two patients no change. Out of the two patients with persistent diplopia, two reported improvement after therapy and three no change. No progression of symptoms was noted in any of the cases. Fourteen out of sixteen treated lesions were stable or regressive following CyberKnife radiosurgery (87%). As no serious adverse effects were reported in this series, CyberKnife therapy was shown to be of great value for local management of orbital metastases.

  10. Implementation of Monte Carlo Simulations for the Gamma Knife System

    NASA Astrophysics Data System (ADS)

    Xiong, W.; Huang, D.; Lee, L.; Feng, J.; Morris, K.; Calugaru, E.; Burman, C.; Li, J.; Ma, C.-M.

    2007-06-01

    Currently the Gamma Knife system is accompanied with a treatment planning system, Leksell GammaPlan (LGP) which is a standard, computer-based treatment planning system for Gamma Knife radiosurgery. In LGP, the dose calculation algorithm does not consider the scatter dose contributions and the inhomogeneity effect due to the skull and air cavities. To improve the dose calculation accuracy, Monte Carlo simulations have been implemented for the Gamma Knife planning system. In this work, the 201 Cobalt-60 sources in the Gamma Knife unit are considered to have the same activity. Each Cobalt-60 source is contained in a cylindric stainless steel capsule. The particle phase space information is stored in four beam data files, which are collected in the inner sides of the 4 treatment helmets, after the Cobalt beam passes through the stationary and helmet collimators. Patient geometries are rebuilt from patient CT data. Twenty two Patients are included in the Monte Carlo simulation for this study. The dose is calculated using Monte Carlo in both homogenous and inhomogeneous geometries with identical beam parameters. To investigate the attenuation effect of the skull bone the dose in a 16cm diameter spherical QA phantom is measured with and without a 1.5mm Lead-covering and also simulated using Monte Carlo. The dose ratios with and without the 1.5mm Lead-covering are 89.8% based on measurements and 89.2% according to Monte Carlo for a 18mm-collimator Helmet. For patient geometries, the Monte Carlo results show that although the relative isodose lines remain almost the same with and without inhomogeneity corrections, the difference in the absolute dose is clinically significant. The average inhomogeneity correction is (3.9 ± 0.90) % for the 22 patients investigated. These results suggest that the inhomogeneity effect should be considered in the dose calculation for Gamma Knife treatment planning.

  11. Single Incision Laparoscopic Cholecystectomy for Gallbladder Duplication

    PubMed Central

    Kabul Gürbulak, Esin; Özşahin, Hamdi; Düzköylü, Yiğit; Akgün, Ismail Ethem; Battal, Muharrem; Gürbulak, Bünyamin

    2015-01-01

    Duplication of the gallbladder is a rare congenital anomaly of the gallbladder, with an estimated prevalence of 1–3 per 3800 individuals. Unless properly diagnosed preoperatively, it can lead to biliary tract injuries and postoperative complications which may require reoperative surgeries. While previously reported cases have been treated with conventional laparoscopic cholecystectomy (LC), treatment with single incision laparoscopic surgery (SILS) has not been reported yet. We herein present the case of a 58-year-old female with gallbladder duplication who was successfully treated with SILS cholecystectomy. PMID:26266074

  12. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification

    PubMed Central

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%. PMID:28046056

  13. Feasibility Study on Applying Radiophotoluminescent Glass Dosimeters for CyberKnife SRS Dose Verification.

    PubMed

    Hsu, Shih-Ming; Hung, Chao-Hsiung; Liao, Yi-Jen; Fu, Hsiao-Mei; Tsai, Jo-Ting; Huang, Yung-Hui; Huang, David Y C

    2017-01-01

    CyberKnife is one of multiple modalities for stereotactic radiosurgery (SRS). Due to the nature of CyberKnife and the characteristics of SRS, dose evaluation of the CyberKnife procedure is critical. A radiophotoluminescent glass dosimeter was used to verify the dose accuracy for the CyberKnife procedure and validate a viable dose verification system for CyberKnife treatment. A radiophotoluminescent glass dosimeter, thermoluminescent dosimeter, and Kodak EDR2 film were used to measure the lateral dose profile and percent depth dose of CyberKnife. A Monte Carlo simulation for dose verification was performed using BEAMnrc to verify the measured results. This study also used a radiophotoluminescent glass dosimeter coupled with an anthropomorphic phantom to evaluate the accuracy of the dose given by CyberKnife. Measurements from the radiophotoluminescent glass dosimeter were compared with the results of a thermoluminescent dosimeter and EDR2 film, and the differences found were less than 5%. The radiophotoluminescent glass dosimeter has some advantages in terms of dose measurements over CyberKnife, such as repeatability, stability, and small effective size. These advantages make radiophotoluminescent glass dosimeters a potential candidate dosimeter for the CyberKnife procedure. This study concludes that radiophotoluminescent glass dosimeters are a promising and reliable dosimeter for CyberKnife dose verification with clinically acceptable accuracy within 5%.

  14. PROSPECTIVE COMPARATIVE STUDY BETWEEN PROXIMAL TRANSVERSE INCISION AND THE CONVENTIONAL LONGITUDINAL INCISIONS FOR CARPAL TUNNEL RELEASE

    PubMed Central

    Teixeira Alves, Marcelo de Pinho

    2015-01-01

    Carpal tunnel syndrome (CTS) is a pathological condition frequently seen in orthopedic consultation offices. It is most common compressive neuropathy and also the one most often treated surgically. CTS is usually diagnosed clinically, through the clinical history, physical examination (Tinel, Phalen and Durkan tests) and complementary examinations, and more specifically, nerve conduction studies. Ultrasound scans and magnetic resonance imaging may also be used. Conservative treatment is reserved for patients presenting with mild symptoms, with little incapacitation, who show good response to non-steroidal or steroidal anti-inflammatory drugs, physiotherapy and lifestyle changes. Surgical treatment is more frequent, and a variety of techniques are used. The goal of the surgery is to decompress the carpal tunnel and, by sectioning the transverse carpal ligament, release the median nerve. The aim of this paper was to compare surgical treatment of CTS by means of a transverse mini-incision made proximally to the carpal canal, with the classic longitudinal incision over the carpal canal. The mini-incision technique was shown to be less invasive and equally effective for treating CTS, with less morbidity than with the classic longitudinal incision. PMID:27022592

  15. Evaluation of maxillary growth: is there any difference using relief incision during palatoplasty?

    PubMed

    Maluf, Ivan; Doro, Ubiratan; Fuchs, Taíse; dos Santos, Diego Esteves; dos Santos Sacomam, Franserg; da Silva Freitas, Renato; Roca, Guilherme Berto

    2014-05-01

    Scar retraction due to exposed bone in palatoplasty is the leading cause of constricted maxilla. Modern techniques have focused on minimizing the effects of scarring by reducing the exposure of the bone area. The objective of the study was to compare the palatal mucoperiosteal detachment with minimal lateral incision, followed by their synthesis, with the maintenance of lateral areas for relaxation (similar to the von Langenbeck technique) and evaluate the transversal development of the maxilla. A prospective, randomized study was conducted, in which the molding of the dental arch of 14 pigs in 2 stages (at 1 month and 5 months) was performed. The pigs were divided into 3 groups: group 1 underwent lateral incision of the palate for mucoperiosteal detachment and maintenance of bone exposure; group 2 underwent mucoperiosteal palatal detachment with lateral access and no bone exposure; and group 3, the control animals, did not undergo any surgical procedures. Measurements of the dental arches were compared between the groups to assess differences in the development of the maxillary transverse diameter. There were no animals lost during the study. Group 1 showed greater growth restriction of the transverse diameter of the maxilla (36%) when compared with groups 2 (56%) and 3 (59%). Groups 2 and 3 showed similar transverse maxillary development, with no statistical difference. The technique of mucoperiosteal detachment without lateral relief incision has the advantage of reducing future morbidity of a constricted maxilla. This study demonstrated that the technique described can reduce rates of maxillary underdevelopment, a significant complication inherent in the procedure for palatoplasty. The lateral incisions reduce maxillary growth by approximately 20% as compared with this technique. Level II of evidence.

  16. Comparison of O-Type HybridKnife to Conventional Knife in Endoscopic Submucosal Dissection for Gastric Mucosal Lesions

    PubMed Central

    Huang, Rui; Yan, Honglin; Ren, Gui; Pan, Yanglin; Zhang, Linhui; Liu, Zhiguo; Guo, Xuegang; Wu, Kaichun

    2016-01-01

    Abstract Endoscopic submucosal dissection (ESD) has been accepted as a minimal invasive alternative to surgery for localized superficial gastrointestinal neoplasms recently. However, the procedure remains to be technically challenging and time consuming. A new dissecting knife with partially insulated tip has been recently developed with built-in injection capability. The purpose of this study was to investigate whether the efficiency of ESD procedure could be improved with this new device. A total of 78 patients, who underwent ESD with gastric mucosal lesions including flat type polyps, adenoma or early gastric cancer, were randomly assigned to either ESD with O-type HybridKnife or conventional ESD knives without waterjet. Procedure time and related factors of ESD were analyzed. ESD procedure time was 43.0 (interquartile range, IQR 27.0–60.0) minutes in HybridKnife group compared to 60.5 (IQR 44.0–86.3) minutes in the control group (P = 0.001). There was no difference in the clinical outcome and the adverse event rate. The former demonstrated more favorable results in lesions ≤4 cm of specimen size (P ≤ 0.0001) and when located in the distal stomach (P = 0.001), also in lesions with fibrosis (P = 0.008). Multivariate regression analysis showed that O-type Knife (P ≤ 0.0001), specimen size (P ≤ 0.0001), and fibrosis (P ≤ 0.0001) were independent predictors of procedure time. The O-type HybridKnife yielded faster procedure time compared to the conventional knives in gastric ESD with a similar safety profile. PMID:27043675

  17. Two-Step Incision for Periarterial Sympathectomy of the Hand

    PubMed Central

    Jeon, Seung Bae; Ahn, Yong Su; Choi, Matthew Seung Suk

    2015-01-01

    Background Surgical scars on the palmar surface of the hand may lead to functional and also aesthetic and psychological consequences. The objective of this study was to introduce a new incision technique for periarterial sympathectomy of the hand and to compare the results of the new two-step incision technique with those of a Koman incision by using an objective questionnaire. Methods A total of 40 patients (17 men and 23 women) with intractable Raynaud's disease or syndrome underwent surgery in our hospital, conducted by a single surgeon, between January 2008 and January 2013. Patients who had undergone extended sympathectomy or vessel graft were excluded. Clinical evaluation of postoperative scars was performed in both groups one year after surgery using the patient and observer scar assessment scale (POSAS) and the Wake Forest University rating scale. Results The total patient score was 8.59 (range, 6-15) in the two-step incision group and 9.62 (range, 7-18) in the Koman incision group. A significant difference was found between the groups in the total PS score (P-value=0.034) but not in the total observer score. Our analysis found no significant difference in preoperative and postoperative Wake Forest University rating scale scores between the two-step and Koman incision groups. The time required for recovery prior to returning to work after surgery was shorter in the two-step incision group, with a mean of 29.48 days in the two-step incision group and 34.15 days in the Koman incision group (P=0.03). Conclusions Compared to the Koman incision, the new two-step incision technique provides better aesthetic results, similar symptom improvement, and a reduction in the recovery time required before returning to work. Furthermore, this incision allows the surgeon to access a wide surgical field and a sufficient exposure of anatomical structures. PMID:26618125

  18. Two-Step Incision for Periarterial Sympathectomy of the Hand.

    PubMed

    Jeon, Seung Bae; Ahn, Hee Chang; Ahn, Yong Su; Choi, Matthew Seung Suk

    2015-11-01

    Surgical scars on the palmar surface of the hand may lead to functional and also aesthetic and psychological consequences. The objective of this study was to introduce a new incision technique for periarterial sympathectomy of the hand and to compare the results of the new two-step incision technique with those of a Koman incision by using an objective questionnaire. A total of 40 patients (17 men and 23 women) with intractable Raynaud's disease or syndrome underwent surgery in our hospital, conducted by a single surgeon, between January 2008 and January 2013. Patients who had undergone extended sympathectomy or vessel graft were excluded. Clinical evaluation of postoperative scars was performed in both groups one year after surgery using the patient and observer scar assessment scale (POSAS) and the Wake Forest University rating scale. The total patient score was 8.59 (range, 6-15) in the two-step incision group and 9.62 (range, 7-18) in the Koman incision group. A significant difference was found between the groups in the total PS score (P-value=0.034) but not in the total observer score. Our analysis found no significant difference in preoperative and postoperative Wake Forest University rating scale scores between the two-step and Koman incision groups. The time required for recovery prior to returning to work after surgery was shorter in the two-step incision group, with a mean of 29.48 days in the two-step incision group and 34.15 days in the Koman incision group (P=0.03). Compared to the Koman incision, the new two-step incision technique provides better aesthetic results, similar symptom improvement, and a reduction in the recovery time required before returning to work. Furthermore, this incision allows the surgeon to access a wide surgical field and a sufficient exposure of anatomical structures.

  19. Determination of kQ using MLC-collimated rectangular fields for absolute dosimetry of the CyberKnife.

    PubMed

    Gersh, Jacob A; Willett, Benjamin

    2015-11-01

    Traditional CyberKnife (CK) calibration uses TG-51, which requires kQ to be defined using the standard reference condition of 100 cm SSD in a 10 cm×10 cm field. Since the CK is calibrated using a 6 cm fixed-aperture collimating cone at 80 cm SAD, the BJR-25 method is commonly used to relate circular-field PDDs to square-field PDDs for kQ determination. Using the InCise MLC system, the CK is able to deliver rectangular fields, allowing a more direct measurement of %dd(10 cm) using conventional reference conditions. We define the PDD correction factor (CPDD) as the ratio of %dd(10 cm) measured using CK reference conditions to that measured using standard TG-51 reference conditions. Using four ionization chambers (A1SL, CC08, CC13, and A19), %dd(10 cm) is measured using a 6 cm fixed cone at 80 cm SSD and at 100 cm SSD using an effective 10 cm×10 cm MLC-collimated field. These values are used to calculate CPDD, while the latter is used to directly calculate a kQ value. This direct kQ value is then compared to values determined using the BJR-25 method. Using the MLC system, this study demonstrates conversion between the %dd(10 cm) measured using CyberKnife reference conditions and TG-51 reference conditions. These values provide the means for derivation of a kQ curve as a function of direct measurements of %dd(10 cm) using a 6 cm fixed-aperture collimating cone at 80 cm SSD. PACS number: 87.55.Qr.

  20. Strong alkalinization of Chara cell surface in the area of cell wall incision as an early event in mechanoperception.

    PubMed

    Bulychev, Alexander A; Alova, Anna V; Bibikova, Tatiana N

    2013-11-01

    Mechanical wounding of cell walls occurring in plants under the impact of pathogens or herbivores can be mimicked by cell wall incision with a glass micropipette. Measurements of pH at the surface of Chara corallina internodes following microperforation of cell wall revealed a rapid (10-30s) localized alkalinization of the apoplast after a lag period of 10-20s. The pH increase induced by incision could be as large as 3 pH units and relaxed slowly, with a halftime up to 20min. The axial pH profile around the incision zone was bell-shaped and localized to a small area, extending over a distance of about 100μm. The pH response was suppressed by lowering cell turgor upon the replacement of artificial pond water (APW) with APW containing 50mM sorbitol. Stretching of the plasma membrane during its impression into the cell wall defect is likely to activate the Ca(2+) channels, as evidenced from sensitivity of the incision-induced alkalinization to the external calcium concentration and to the addition of Ca(2+)-channel blockers, such as La(3+), Gd(3+), and Zn(2+). The maximal pH values attained at the incision site (~10.0) were close to pH in light-dependent alkaline zones of Chara cells. The involvement of cytoskeleton in the origin of alkaline patch was documented by observations that the incision-induced pH transients were suppressed by the inhibitors of microtubules (oryzalin and taxol) and, to a lesser extent, by the actin inhibitor (cytochalasin B). The results indicate that the localized increase in apoplastic pH is an early event in mechanoperception and depends on light, cytoskeleton, and intracellular calcium. © 2013.

  1. Microbubble incision as a new rescue technique for big-bubble deep anterior lamellar keratoplasty with failed bubble formation.

    PubMed

    Riss, Stephan; Heindl, Ludwig M; Bachmann, Björn O; Kruse, Friedrich E; Cursiefen, Claus

    2013-02-01

    To describe a new surgical technique allowing dissection down to Descemet membrane in big-bubble deep anterior lamellar keratoplasty (DALK) with failed big-bubble formation (the "microbubble incision technique"). This is an interventional case series of 10 consecutive patients with keratoconus undergoing intended big-bubble DALK with failure to establish a normal big bubble. In all patients, repeated air injections into the stroma were performed, leaving a whitish colored stroma. Lamellar dissection as far down as possible was then performed within this white tissue. As soon as the anterior chamber was visible, a large remaining intrastromal air bubble was incised with a sharp 15-degree knife introduced perpendicular to the tissue to open up this predescemetic bubble. If deeper air bubbles were still visible, this approach was repeated. Using a blunt spatula, this new layer was then prepared and viscodissection performed. Using this novel approach, in 9 of the 10 patients, it was possible to dissect down to Descemet membrane. Macroperforation made conversion to penetrating keratoplasty necessary in 1 patient. Microperforations not necessitating conversion occurred in 2 patients. All 9 patients with "rescued" DALK had an uneventful postoperative course and had a mean visual acuity of 20/63 ± 20/125 (range, 20/500-20/50) and a mean endothelial cell count of 1672 ± 163 cells per square millimeter (range, 1493-1867 cells/mm) at 3 months. Microbubble incision is a new rescue technique for big-bubble DALK patients without bubble formation allowing for a safer dissection down to Descemet membrane.

  2. Endoscopic submucosal dissection of early gastric neoplasia with a water jet-assisted knife: a Western, single-center experience.

    PubMed

    Schumacher, Brigitte; Charton, Jean-Pierre; Nordmann, Thomas; Vieth, Michael; Enderle, Markus; Neuhaus, Horst

    2012-06-01

    Endoscopic submucosal dissection (ESD) of early gastric neoplasia has not yet been established in Western countries because of a lack of data and the difficult, time-consuming, and hazardous nature of the method. Some of the technical limitations may be overcome by use of a water jet-assisted knife, which allows a combination of a high-pressure water jet and electrosurgical interventions. To evaluate the efficacy and safety of water jet-assisted ESD (WESD) with a water jet-assisted knife in selected patients with early gastric neoplasia. Single-center, prospective study. This study involved 29 consecutive patients (13 female; median age 61 years; age range 35-93 years) with early gastric neoplasia that met the expanded criteria of the Japanese Gastric Cancer Association. Histology of biopsies had shown gastric adenocarcinoma in 21 cases, adenoma in 8 case, and suspicion of a GI stromal tumor in 1 case. The median maximal diameter of the lesions was 20 mm (range 10-40 mm). All procedures were done with patients under sedation with propofol. The water jet-assisted knife was used for setting coagulation markers around the neoplastic lesions, then for circumferential incision and dissection in combination with repeated submucosal injection of saline solution with a water jet system. Bleeding was treated with diathermia by use of the water jet-assisted knife or hemostatic forceps in case of failure or larger vessels. Clips were used for closure of perforations. Complete resection of neoplasia, procedure time, complication and recurrence rates. According to endoscopic criteria, complete resection of the targeted area could be achieved in all cases, with an en bloc resection rate of 90%. The median procedure duration was 74 minutes (range 15-402 minutes). Exchange of the device was needed in only 10 cases because of severe bleeding from larger vessels, which could be managed by use of hemostatic forceps. The 30-day morbidity rate was 4 of 30 (13.8%) because of

  3. Bipolar plasma vaporization versus monopolar TUR and "cold-knife" TUI in secondary bladder neck sclerosis - an evidence based, retrospective critical comparison in a single center clinical setting.

    PubMed

    Moldoveanu, C; Geavlete, B; Jecu, M; Stanescu, F; Adou, L; Bulai, C; Ene, C; Geavlete, P

    2014-03-15

    A long term, retrospective study was performed aiming to outline a critical comparison concerning the efficacy, safety and durability of the bipolar plasma vaporization (BPV), standard monopolar transurethral resection (TUR) and "cold-knife" "star" transurethral incision (TUI) in secondary bladder neck sclerosis (BNS) cases. Of the 126 patients included in the trial based on maximum flow rate (Qmax) below 10 mL/s and International Prostate Symptom Score (IPSS) over 19, classical resection was performed in 46 cases, "cold-knife" TUI in 37 cases and bipolar vaporization in 43 patients. The evaluation protocol comprised IPSS, QoL (quality of life) score, Qmax and PVR (post-voiding residual urinary volume) assessment performed at 1, 3, 6, 12, 18 and 24 months after the initial intervention. Significant intraoperative complications (capsular perforation - 8.7%; bleeding - 4.3%) occurred secondary to monopolar resection. "Star" TUI was the fastest technique, followed by plasma-button vaporization (7.2 and 11.4 versus 16.5 minutes). BPV and TUI patients benefitted from the shortest catheterization periods (0.75 and 1 versus 2.0 days) and hospital stays (1.0 and 1.25 versus 2.0 days). Immediate postoperative adverse events consisted of hematuria (6.5% of the TUR cases) and acute urinary retention (8.1% of the TUI group). Significantly higher long term BNS recurrence rates requiring re-treatment were established in the TUI (18.7%) and TUR (12.8%) series by comparison to BPV (5.4%). Among patients that completed the follow-up protocol, equivalent IPSS, QoL, Qmax and PVR features were determined in the 3 study arms. The plasma vaporization approach was confirmed as a successful match to conventional TUR and "cold-knife" TUI in terms of surgical safety profile, postoperative recovery, therapeutic durability and urodynamic and symptom score parameters.

  4. PARAMAGNETIC RELAXATION IN CRYSTALS.

    DTIC Science & Technology

    CRYSTALS, PARAMAGNETIC RESONANCE, RELAXATION TIME , CRYSTAL DEFECTS, QUARTZ, GLASS, STRAIN(MECHANICS), TEMPERATURE, NUCLEAR SPINS, HYDROGEN, CALCIUM COMPOUNDS, FLUORIDES, COLOR CENTERS, PHONONS, OXYGEN.

  5. Incised bifurcations and uneven radial distribution of channel incision in the Wax Lake Delta, USA

    NASA Astrophysics Data System (ADS)

    Shaw, J. B.; Mohrig, D. C.

    2009-12-01

    The Wax Lake Delta, southern Louisiana, has been found to possess distributary channels whose beds range from non-depositional to strongly erosional, cut into pre-delta muds. This discovery was unexpected given that the overall depositional setting has created greater than 100 square km of subareal land in less than 40 years. Furthermore, while map views of the system reveal an approximately radial symmetric depositional pattern and delta shape, the pattern of channel incision is unevenly distributed across the distributary network. The apex of Wax Lake delta is defined by an adverse ramp with a bed slope of 0.006 that connects the deep feeder channel (18m) to the shallower, first set of bifurcations. We find two distinct zones of channel bottom character within the distributary network. The first zone consists of substantially incised channels stemming from the bifurcation directly downstream of the Wax Lake Outlet and ramp described above. The maximum depth of incision into pre-delta mud decreases from roughly 3m to 1.5m nearer the delta front. This incision can make up greater than 1/3 of the total flow depth in these channels. The second zone is characterized by non-depositional channel bottoms that are located off to either side of the swath of incisional channels. These channels sit on top of the pre-delta substrate, showing no significant erosion or deposition. The occurrence of bed erosion and non-deposition throughout the observed channel network raises the previously unasked questions of whether these regimes extend to the very front of the delta located 10km from the delta apex, and whether incision plays an important role in the original development of bifurcations on this delta. The development of channel bifurcations under conditions with significant bed incision has yet to be discussed in the river bifurcation literature, and may play an important role in the observed constancy of channel network patterns. Using USACE bathymetry surveys as well as

  6. A noninvasive eye fixation monitoring system for CyberKnife radiotherapy of choroidal and orbital tumors

    SciTech Connect

    Daftari, I. K.; Petti, P. L.; Larson, D. A.; O'Brien, J. M.; Phillips, T. L.

    2009-03-15

    A new noninvasive monitoring system for fixing the eye has been developed to treat orbital and choroidal tumors with CyberKnife-based radiotherapy. This device monitors the eye during CT/MRI scanning and during treatment. The results of this study demonstrate the feasibility of the fixation light system for CyberKnife-based treatments of orbital and choroidal tumors and supports the idea that larger choroidal melanomas and choroidal metastases could be treated with CyberKnife without implanting fiducial markers.

  7. Visualizing morphological changes of clear corneal cataract incisions with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Rao, Bin; Zhang, Jun; Taban, Mehran; McDonnell, Peter J.; Chen, Zhongping

    2004-07-01

    Dynamic morphological changes of clear corneal cataract incisions are studied with Optical Coherence Tomography (OCT). Two opposite types of dynamic incision wound behaviors are documented. A stable incision angle range is found to be existent for single-planed, clear corneal cataract incisions. When well pressurized, incision angles within this stable range result in well-apposed incision edges that resist gapping while incision angles falling outside this range have a larger tendency for wound leakage. It is also shown that a two-planed incision can effectively expand the stable range. For incision angles outside the stable range, the farther the incision angle is away from stable range, the larger the gap between incision wound edges when well pressurized. Thus, incision construction method has a major impact on the self-sealing capability of the incision wounds. In this investigation, OCT has been demonstrated as an effective modality for imaging and monitoring corneal surgery.

  8. Optical coherence tomography (OCT) guided smart laser knife for cancer surgery (Conference Presentation)

    NASA Astrophysics Data System (ADS)

    Katta, Nitesh; Mcelroy, Austin; Estrada, Arnold; Milner, Thomas E.

    2017-02-01

    Neurological cancer surgeries require specialized tools that enhance imaging for precise cutting and removal of tissue without damaging adjacent neurological structures. The novel combination of high-resolution fast optical coherence tomography (OCT) alongside short pulsed nanosecond thulium (Tm) lasers offers stark advantages utilizing the superior beam quality, high volumetric tissue removal rates of thulium lasers with minimal residual thermal footprint in the tissue and avoiding damage to delicate sub-surface structures (e.g., nerves and microvessels); which has not been showcased before. A bench-top system is constructed, using a 15W 1940nm nanosecond pulsed Tm fiber laser (500uJ pulse energy, 100ns pulse duration, 30kHz repetition rate) for removing tissue and a swept source laser (1310±70nm, 100kHz sweep rate) is utilized for OCT imaging, forming a combined Tm/OCT system - a smart laser knife. The OCT image-guidance informs the Tm laser for cutting/removal of targeted tissue structures. Tissue phantoms were constructed to demonstrate surgical incision with blood vessel avoidance on the surface where 2mm wide 600um deep cuts are executed around the vessel using OCT to guide the procedure. Cutting up to delicate subsurface blood vessels (2mm deep) is demonstrated while avoiding damage to their walls. A tissue removal rate of 5mm^3/sec is obtained from the bench-top system. We constructed a blow-off model to characterize Tm cut depths taking into account the absorption coefficients and beam delivery systems to compute Arrhenius damage integrals. The model is used to compare predicted tissue removal rate and residual thermal injury with experimental values in response to Tm laser-tissue modification.

  9. Thymic Carcinoma Treated by CyberKnife Stereotactic Body Radiotherapy

    PubMed Central

    Miyazaki, Shinichiro

    2017-01-01

    The standard treatment for advanced thymic carcinoma has not yet been established. Most patients have no symptoms until the advanced stage. Radiation therapy has been used for advanced stage cancer, usually in combination with surgery or chemotherapy; however, the survival rates are 30%-50%. We performed hypofractionated stereotactic radiotherapy with CyberKnife (Accuray, Sunnyvale, CA, USA) for 10 cases of advanced thymic cancer. All cases reached at least partial remission (PR) in two months with progression-free irradiated lesions and minimal radiation-related toxicity. It took only seven to 12 days for each therapy that did not require admission. CyberKnife is beneficial for patients even at the terminal stage. PMID:28367393

  10. SRAO: optical design and the dual-knife-edge WFS

    NASA Astrophysics Data System (ADS)

    Ziegler, Carl; Law, Nicholas M.; Tokovinin, Andrei

    2016-07-01

    The Southern Robotic Adaptive Optics (SRAO) instrument will bring the proven high-efficiency capabilities of Robo-AO to the Southern-Hemisphere, providing the unique capability to image with high-angular-resolution thousands of targets per year across the entire sky. Deployed on the modern 4.1m SOAR telescope located on Cerro Tololo, the NGS AO system will use an innovative dual-knife-edge wavefront sensor, similar to a pyramid sensor, to enable guiding on targets down to V=16 with diffraction limited resolution in the NIR. The dual-knife-edge wavefront sensor can be up to two orders of magnitude less costly than custom glass pyramids, with similar wavefront error sensitivity and minimal chromatic aberrations. SRAO is capable of observing hundreds of targets a night through automation, allowing confirmation and characterization of the large number of exoplanets produced by current and future missions.

  11. Detrital Zircon Record of Colorado River Incision

    NASA Astrophysics Data System (ADS)

    Kimbrough, D.; Grove, M.; Gehrels, G.; Dorsey, R.; House, K. P.; Howard, K.; Pearthree, P. A.; Spencer, J. E.; Mahoney, B.

    2007-05-01

    The Colorado River is a large, youthful, unequilibrated continental drainage system the base-level for which was established rather abruptly between 5 and 6 million years ago in conjunction with Gulf of California rifting and establishment of the modern river course through the western Grand Canyon and lower Colorado river region. New laser ablation ICPMS detrital zircon U-Pb analyses (~3000) from ~40 samples provide insight into details relating to the cause, timing and consequences of river inception. These samples encompass (1) the modern Colorado River delta, (2) major tributaries including the Green, "Grand", San Juan, Little Colorado and Gila rivers (3) late Miocene to Pliocene sediments along the lower Colorado (4) late Miocene to Pleistocene deltaic and fluvial sediments of the Imperial and Palm Spring Groups in the western Salton Trough, and (5) late Miocene- early Pliocene Bidahochi Formation of eastern Arizona. Data from the western Salton Trough and modern delta yield strata yield remarkably homogeneous age distributions that indicate there was little evolution in Colorado River sediment composition since 5.3 Ma. Detrital zircon is dominated by a mix of local southwest US cratonal basement (1.7 and 1.4 Ga) plus reworked supracrustal sequences of the Colorado Plateau that provide Neoproterozoic, 1.1 Ga, and early Paleozoic zircons. A relative paucity of Grenville-age grains in the earliest part of the delta sequence may reflect an early stage of the modern river prior to deep incision through Colorado Plateau erg deposits. The strong homogeneity of the detrital zircon record from late Miocene to the present is consistent with the `lake spillover model' for inception and integration of the modern Colorado River drainage. Abrupt integration of the lower Colorado River after 5.6 Ma is clearly recorded by detrital zircon ages from the laucustrine Bouse Formation and Bullhead alluvium aggradational package. Fluvial-laucustrine deposits of the Bidahochi

  12. Isolated subtalar arthrodesis through minimal incision surgery.

    PubMed

    Carranza-Bencano, A; Tejero-García, S; Del Castillo-Blanco, G; Fernández-Torres, J J; Alegrete-Parra, A

    2013-08-01

    In recent years there has been an increase in the use of minimally invasive techniques, such as arthroscopy, percutaneous, and minimally invasive incisions, for foot and ankle surgery. The purpose of this study was to analyze the fusion rate and clinical results of isolated subtalar arthrodesis (ISA) using the novel and original technique of minimal incision surgery (MIS). There were a total of 77 feet in 76 patients who underwent ISA and were followed for 50 months on average (range, 15-108). The first 30 cases were evaluated retrospectively, and 47 cases were evaluated prospectively. MIS without tourniquet was used in all cases and fusion was assessed radiographically and clinically. Clinical outcome measures used were the Angus and Cowell Scoring System, AOFAS Ankle-Hindfoot, the SF-36, and a patient satisfaction questionnaire 12 months after the intervention. Radiographic and clinical consolidation was achieved in 92% of cases. Main outcomes were "good" in 57 patients as determined by the Angus and Cowell criteria, with 13 "fair" and 7 "poor" results. In the prospective group, AOFAS scores improved by 47.6 points (95% CI: 50.7-42.5) 12 months after surgical intervention. SF-36 outcomes improved by 14.5 points (95% CI: 11.58-17.31) in the mental summary component and 4.2 points (95% CI: 2.2-6.1) in the physical summary component. We recorded no cases of early complications such as wound infections, neurovascular damage, or delayed wound healing. To our knowledge, the present series represents the largest study on subtalar arthrodesis using minimally invasive surgery. The data obtained showed a similar rate of bony union and clinical outcomes compared with the literature, but without early wound complications. ISA using the MIS technique was a good option for patients at greater risk of wound healing complications. Level IV, case series.

  13. Cross-Grain Knife Planing Improves Surface Quality and Utilization of Aspen

    Treesearch

    Harold A. Stewart

    1971-01-01

    Aspen at 6 percent moisture content was planed parallel to the grain and across the grain on a cabinet planer with a 25? rake angle, 1/16- and 1/32-inch depth of cut, and 20 knife marks per inch. Aspen was also cross-grain knife planed with a 45? rake angle, 1/32-, 1/16-, and 1/8-inch depths of cut, and 20, 10, 5, and 2.5 knife marks per inch. Cross-grain knife...

  14. No need to change the skin knife in modern arthroplasty surgery.

    PubMed

    Ottesen, C; Skovby, A; Troelsen, A; Specht, C; Friis-Møller, A; Husted, H

    2014-08-01

    Earlier studies have found varying contamination rates using separate skin and deep knives in total hip (THA) and total knee (TKA) arthroplasty surgery. Previous studies were primarily conducted in the setting of concomitant use of laminar airflow and/or plastic adhesive draping. This has lead to conflicting conclusions regarding discarding the skin knife or not. This study evaluates the prevalence of contamination of a separate skin knife using modern antiseptic technique in primary THA and TKA without laminar airflow. Three knives from each primary THA and TKA surgery in non-laminar airflow operating rooms were collected: one used for the skin, one used for deeper tissues and one control knife. A total of 831 knife blades from 277 patients were cultured 12 days. Contamination of the skin knife was found in eight patients (2.8 %), contamination of the "deep" knife in five patients (1.8 %) and contamination of the control knife in five patients (1.8 %). No patient developed an infection with 1-year follow-up. Our findings suggest a very low rate of contamination of the skin knife using modern antiseptic technique without laminar airflow and/or plastic adhesive draping and do not support the use of a separate skin knife in arthroplasty surgery.

  15. Gamma Knife treatment of low-grade gliomas in children.

    PubMed

    Ekşi, Murat Şakir; Yılmaz, Baran; Akakın, Akın; Toktaş, Zafer Orkun; Kaur, Ahmet Cemil; Demir, Mustafa Kemal; Kılıç, Türker

    2015-11-01

    Low-grade gliomas have good overall survival rates in pediatric patients compared to adults. There are some case series that reported the effectiveness and safety of Gamma Knife radiosurgery, yet they are limited in number of patients. We aimed to review the relevant literature for pediatric low-grade glial tumors treated with stereotactic radiosurgery, specifically Gamma Knife radiosurgery, and to present an exemplary case. A 6-year-old boy was admitted to clinic due to head trauma. He was alert, cooperative, and had no obvious motor or sensorial deficit. A head CT scan depicted a hypodense zone at the right caudate nucleus. The brain magnetic resonance imaging (MRI) depicted a mass lesion at the same location. A stereotactic biopsy was performed. Histopathological diagnosis was low-grade astrocytoma (grade II, World Health Organization (WHO) classification, 2007). Gamma Knife radiosurgery was applied to the tumor bed. Tumor volume was 21.85 cm(3). Fourteen gray was given to 50% isodose segment of the lesion (maximal dose of 28 Gy). The tumor has disappeared totally in 4 months, and the patient was tumor-free 21 months after the initial treatment. The presented literature review represents mostly single-center experiences with different patient and treatment characteristics. Accordingly, a mean/median margin dose of 11.3-15 Gy with Gamma Knife radiosurgery (GKRS) is successful in treatment of pediatric and adult low-grade glial tumor patients. However, prospective studies with a large cohort of pediatric patients should be conducted to make a more comprehensive conclusion for effectiveness and safety of GKRS in pediatric low-grade glial tumors.

  16. Wound Hypoxia in Deep Tissue after Incision in the Rats

    PubMed Central

    Kang, Sinyoung; Lee, Dongchul; Theusch, Brett E.; Arpey, Christopher J.; Brennan, Timothy J.

    2013-01-01

    Our previous studies using rat models of incisional pain have demonstrated that tissue lactate levels increase and pH decreases for several days after incision, suggesting the presence of an ischemic-like condition. The purpose of this study was to evaluate the time course and the extent of tissue hypoxia that develops in incised muscle and skin. We directly measured oxygen tension at several time points after incisions of the gastrocnemius muscle, the paraspinal skin, and the plantar hindpaw in anesthetized rats using an oxygen-sensitive microelectrode. In vivo hypoxia of the incised tissues was also evaluated immunohistochemically using a hypoxia marker pimonidazole hydrochloride. To minimized inter-subject variability, unincised contralateral tissues were used as a control. Tissue oxygen tension was decreased in both skeletal muscle and skin compared to control, for several days after incision: when measured directly, oxygen tension decreased immediately and remained low for several days after incisions. Pimonidazole immunostaining revealed hypoxic areas in incised muscle and skin for several days. By postoperative day 10, tissue oxygen tension recovered to that of control tissue. These results support the evidence that a hypoxic condition is present in deep tissue after incisions and that an ischemic-like mechanism may contribute to postoperative pain. PMID:23926943

  17. SMA Syndrome Treated by Single Incision Laparoscopic Duodenojejunostomy.

    PubMed

    Kim, Sungsoo; Kim, Yoo Seok; Min, Young-Don

    2014-01-01

    Superior mesenteric artery (SMA) syndrome is a mechanical duodenal obstruction by the SMA. The traditional approach to SMA syndrome was open bypass surgery. Nowadays, a conventional approach has been replaced by laparoscopic surgery. But single incision laparoscopic approach for SMA syndrome is rare. Herein, we report the first case of SMA syndrome patient who was treated by single incision laparoscopic duodenojejunostomy.

  18. Worldwide variance in the potential utilization of Gamma Knife radiosurgery.

    PubMed

    Hamilton, Travis; Dade Lunsford, L

    2016-12-01

    OBJECTIVE The role of Gamma Knife radiosurgery (GKRS) has expanded worldwide during the past 3 decades. The authors sought to evaluate whether experienced users vary in their estimate of its potential use. METHODS Sixty-six current Gamma Knife users from 24 countries responded to an electronic survey. They estimated the potential role of GKRS for benign and malignant tumors, vascular malformations, and functional disorders. These estimates were compared with published disease epidemiological statistics and the 2014 use reports provided by the Leksell Gamma Knife Society (16,750 cases). RESULTS Respondents reported no significant variation in the estimated use in many conditions for which GKRS is performed: meningiomas, vestibular schwannomas, and arteriovenous malformations. Significant variance in the estimated use of GKRS was noted for pituitary tumors, craniopharyngiomas, and cavernous malformations. For many current indications, the authors found significant variance in GKRS users based in the Americas, Europe, and Asia. Experts estimated that GKRS was used in only 8.5% of the 196,000 eligible cases in 2014. CONCLUSIONS Although there was a general worldwide consensus regarding many major indications for GKRS, significant variability was noted for several more controversial roles. This expert opinion survey also suggested that GKRS is significantly underutilized for many current diagnoses, especially in the Americas. Future studies should be conducted to investigate health care barriers to GKRS for many patients.

  19. A knife-edge array field emission cathode

    SciTech Connect

    Lee, Bo

    1994-08-01

    many cathode applications require a new type of cathode that is able to produce short pulsed electron beams at high emission current. Gated field emitter arrays of micrometer size are recognized as candidates to meet this need and have become the research focus of vacuum microelectronics. Existing fabrication methods produce emitters that are limited either in frequency response or in current emission. One reason is that the structure of these emitters are not sufficiently optimized. In this study, the author investigated the factors that affect the performance of field emitters. An optimum emitter structure, the knife-edge field emitter array, was developed from the analysis. Large field enhancement factor, large effective emission area, and small emitter capacitance are the advantages of the structure. The author next explored various options of fabricating the knife-edge emitter structure. He proposed a unique thin film process procedure and developed the fabrication techniques to build the emitters on (110) silicon wafers. Data from the initial cathode tests showed very low onset voltages and Fowler-Nordheim type emission. Emission simulation based on the fabricated emitter structure indicated that the knife-edge emitter arrays have the potential to produce high performance in modulation frequency and current emission. Several fabrication issues that await further development are discussed and possible solutions are suggested.

  20. TEACHING NEUROMUSCULAR RELAXATION.

    ERIC Educational Resources Information Center

    NORRIS, JEANNE E.; STEINHAUS, ARTHUR H.

    THIS STUDY ATTEMPTED TO FIND OUT WHETHER (1) THE METHODS FOR ATTAINING NEUROMUSCULAR RELAXATION THAT HAVE PROVED FRUITFUL IN THE ONE-TO-ONE RELATIONSHIP OF THE CLINIC CAN BE SUCCESSFULLY ADAPTED TO THE TEACHER-CLASS RELATIONSHIP OF THE CLASSROOM AND GYMNASIUM, AND (2) NEUROMUSCULAR RELAXATION CAN BE TAUGHT SUCCESSFULLY BY AN APPROPRIATELY TRAINED…

  1. Incision into the eastern Andean Plateau during Pliocene cooling.

    PubMed

    Lease, Richard O; Ehlers, Todd A

    2013-08-16

    Canyon incision into mountain topography is commonly used as a proxy for surface uplift driven by tectonic or geodynamic processes, but climatic changes can also instigate incision. The ~1250-kilometer (km)-long eastern margin of the Andean Plateau hosts a series of 1.5- to 2.5-km-deep canyons that cross major deformation zones. Using (U-Th)/He thermochronology, we document a transition from Miocene faulting to Pliocene canyon incision across the northeastern plateau margin. Regionally, widespread Pliocene incision into the eastern plateau margin is concurrent with a shift in global climate from early Pliocene warmth to late Pliocene cooling. Enhanced moisture transport onto the Andean Plateau driven by sea surface temperature changes during cooling is the likely pacemaker for canyon incision.

  2. Relaxation of magnetotail plasmas

    NASA Technical Reports Server (NTRS)

    Bhattacharjee, A.

    1987-01-01

    A quasi-thermodynamic model is presented for the relaxation of magnetotail plasmas during substorms, followed by quiet times. It is proposed that the plasma relaxes to a state of low-potential energy subject to a small number of global constraints. The constraints are exactly preserved by all ideal motions and, approximately, by a wide class of motions of the plasma undergoing magnetic reconnection. A variational principle which minimizes the free energy predicts the relaxed state. Exact, two-dimensional solutions of the relaxed state are obtained. A universal feature of the exact solutions is a chain of magnetic islands along the tail axis. Sufficient conditions for the stability of relaxed states are obtained from the second variation of the free-energy functional.

  3. Influence of Incision Location on Transmitter Loss, Healing, Incision Lengths, Suture Retention, and Growth of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greggory L.; Woodley, Christa M.; Deters, Katherine A.

    2010-05-11

    In this study, conducted by Pacific Northwest National Laboratory for the U.S. Army Corps of Engineers, Portland District, we measured differences in survival and growth, incision openness, transmitter loss, wound healing, and erythema among abdominal incisions on the linea alba, lateral and parallel to the linea alba (muscle-cutting), and following the underlying muscle fibers (muscle-sparing). A total of 936 juvenile Chinook salmon were implanted with both Juvenile Salmon Acoustic Tracking System transmitters (0.43 g dry) and passive integrated transponder tags. Fish were held at 12°C (n = 468) or 20°C (n = 468) and examined once weekly over 98 days. We found survival and growth did not differ among incision groups or between temperature treatment groups. Incisions on the linea alba had less openness than muscle-cutting and muscle-sparing incisions during the first 14 days when fish were held at 12°C or 20°C. Transmitter loss was not different among incision locations by day 28 when fish were held at 12°C or 20°C. However, incisions on the linea alba had greater transmitter loss than muscle-cutting and muscle-sparing incisions by day 98 at 12°C. Results for wound closure and erythema differed among temperature groups. Results from our study will be used to improve fish-tagging procedures for future studies using acoustic or radio transmitters.

  4. Direct measures of mechanical energy for knife mill size reduction

    SciTech Connect

    Bitra, V.S.P.; Womac, A.R.; Igathinathane, C.; Miu, P.I; Yang, Y.T.; Smith, D.R.; Chevanan, Nehru; Sokhansanj, Shahabaddine

    2009-08-01

    Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be 0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These

  5. Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation

    PubMed Central

    Murovic, Judith A.; Charles Cho, S.

    2009-01-01

    Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \\and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife

  6. Surgical strategies for managing foraminal nerve sheath tumors: the emerging role of CyberKnife ablation.

    PubMed

    Murovic, Judith A; Charles Cho, S; Park, Jon

    2010-02-01

    Sixteen Stanford University Medical Center (SUMC) patients with foraminal nerve sheath tumors had charts reviewed. CyberKnife radiosurgery was innovative in management. Parameters were evaluated for 16 foraminal nerve sheath tumors undergoing surgery, some with CyberKnife. Three neurofibromas had associated neurofibromatosis type 1 (NF1). Eleven patients had one resection; others had CyberKnife after one (two) and two (three) operations. The malignant peripheral nerve sheath tumor (MPNST) had prior field-radiation and adds another case. Approaches included laminotomy and laminectomies with partial (three) or total (two) facetectomies/fusions. Two cases each had supraclavicular, lateral extracavitary, retroperitoneal and Wiltze and costotransversectomy/thoracotomy procedures. Two underwent a laminectomy/partial facetectomy, then CyberKnife. Pre-CyberKnife, one of two others had a laminectomy/partial facetectomy, then total facetectomy/fusion and the other, two supraclavicular approaches. The MPNST had a hemi-laminotomy then laminectomy/total facetectomy/fusion, followed by CyberKnife. Roots were preserved, except in two. Of 11 single-operation-peripheral nerve sheath tumors, the asymptomatic case remained stable, nine (92%) improved and one (9%) worsened. Examinations remained intact in three (27%) and improved in seven (64%). Two having a single operation then CyberKnife had improvement after both. Of two undergoing two operations, one had symptom resolution post-operatively, worsened 4 years post-CyberKnife then has remained unchanged after re-operation. The other such patient improved post-operatively, had no change after re-operation and improved post-CyberKnife. The MPNST had presentation improvement after the first operation, worsened and after the second surgery \\and CyberKnife, the patient expired from tumor spread. In conclusion, surgery is beneficial for pain relief and function preservation in foraminal nerve sheath tumors. Open surgery with CyberKnife

  7. Stab Wound in the Skull Treated with a Medial Supraorbital Craniotomy Through an Incision in the Eyebrow-a Minimally Invasive Approach.

    PubMed

    Araujo, João Luiz Vitorino; Ferraz, Vinicius Ricieri; Vilela, Denes; Sette, Marcelo

    2015-12-01

    The eyebrow incision associated with medial supraorbital craniotomy is a minimally invasive alternative approach to the lesions located in the medial anterior cranial fossa. The main advantages of the medial supraorbital craniotomy regarding frontolateral supraorbital craniotomy are the absence of manipulation of the temporal muscle, less risk of injury to the frontotemporal branch of the facial nerve and a more medial view of the anterior structures such as frontal sinus, olfatory groove and frontal lobe. We report a unique case of cranial stab wound in which a piece of the knife stayed in the frontal sinus and removal was performed using the medial supraorbital approach. There were no complications during surgery, the patient reported mild hypoesthesia in the left frontal region and was discharged on the 7th postoperative day. During follow-up after 2 months, good cosmetic result of the surgical wound and preserved sensitivity of the left frontal region were noted.

  8. Angiomatous lesion and delayed cyst formation after gamma knife surgery for intracranial meningioma: case report and review of literatures.

    PubMed

    Liu, Zhiyong; He, Min; Chen, Hongxu; Liu, Yi; Li, Qiang; Li, Lin; Li, Jin; Chen, Haifeng; Xu, Jianguo

    2015-01-01

    Gamma Knife has become a major therapeutic method for intracranial meningiomas, vascular malformations and schwannomas with exact effect. In recent years an increasing number of delayed complications after Gamma Knife surgery have been reported, such as secondary tumors, cystic changes or cyst formation. But angiomatous lesion and delayed cyst formation after Gamma Knife for intracranial lesion has rarely been reported. Here we report the first case of angiomatous lesion and delayed cyst formation following Gamma Knife for intracranial meningioma and discuss its pathogenesis.

  9. Testing bedrock incision models: Holocene channel evolution, High Cascades, Oregon

    NASA Astrophysics Data System (ADS)

    Sweeney, K. E.; Roering, J. J.; Fonstad, M. A.

    2013-12-01

    There is abundant field evidence that sediment supply controls the incision of bedrock channels by both protecting the bed from incision and providing tools to incise the bed. Despite several theoretical models for sediment-dependent bedrock abrasion, many investigations of natural channel response to climatic, lithologic, or tectonic forcing rely on the stream power model, which does not consider the role of sediment. Here, we use a well-constrained fluvial channel cut into a Holocene lava flow in the High Cascades, Oregon to compare incision predictions of the stream power model and of the full physics of theoretical models for saltation-abrasion incision by bedload and suspended load. The blocky andesite of Collier lava flow erupted from Collier Cone ~1500 years ago, paving over the existing landscape and erasing fine-scale landscape dissection. Since the eruption, a 6 km stream channel has been incised into the lava flow. The channel is comprised of three alluvial reaches with sediment deposits up to 2 m thick and two bedrock gorges with incision of up to 8 m, with larger magnitude incision in the upstream gorge. Abraded forms such as flutes are present in both gorges. Given the low magnitude and duration of modern snowmelt flow in the channel, it is likely that much of the incision was driven by sediment-laden outburst floods from the terminus of Collier Glacier, which is situated just upstream of the lava flow and has produced two outburst floods in the past 100 years. This site is well suited for comparing incision models because of the relatively uniform lithology of the lava flow and our ability to constrain the timing and depth of incision using the undissected lava surface above the channel as an initial condition. Using a simple finite difference scheme with airborne-Lidar-derived pre-incision topography as an initial condition, we predict incision in the two gorges through time with both stream power and sediment-dependent models. Field observations

  10. [Skin sparing incision mastectomy and immediate TRAM flap breast reconstruction].

    PubMed

    Liu, L; Pand, R

    2000-07-01

    In order to achieve a high-quality reconstructed breast, we improved the operation method using the skin sparing incision mastectomy and immediate TRAM flap breast reconstruction. Patients with duct carcinoma in situ were selected to undergo mastectomy with a skin sparing incision. The site of the previous biopsy incision was marked around the areola, and then the preferred skin sparing incision included the nipple-areola complex and a margin around the biopsy site for the non-ptotic breast. The excised skin was replaced as precisely as possible with the TRAM flap skin immediately. While the mastectomy was being performed the TRAM flap was incised and elevated. The pedicled or free TRAM flap has been used for 34 patients. Nipple-areola reconstruction was made at the second stage. The results of the skin sparing breast reconstruction are better than other breast reconstruction techniques in the breast's shape, colour, sensation, symmetry and incision scar. Skin sparing incision mastectomy with immediate TRAM flap breast reconstruction technique is an ideal breast reconstructive method for the patients with breast duct carcinoma in situ. The advantages of the method include 1. The TRAM flap is an autograft without rejection; 2. The reconstructed breast has good shape and better sensation than other autograft reconstructive techniques since most breast skin has been spared; 3. The symmetry of the reconstructed breast with the contralateral breast is improved.

  11. Gamma Knife 3-D dose distribution near the area of tissue inhomogeneities by normoxic gel dosimetry

    SciTech Connect

    Isbakan, Fatih; Uelgen, Yekta; Bilge, Hatice; Ozen, Zeynep; Agus, Onur; Buyuksarac, Bora

    2007-05-15

    The accuracy of the Leksell GammaPlan registered , the dose planning system of the Gamma Knife Model-B, was evaluated near tissue inhomogeneities, using the gel dosimetry method. The lack of electronic equilibrium around the small-diameter gamma beams can cause dose calculation errors in the neighborhood of an air-tissue interface. An experiment was designed to investigate the effects of inhomogeneity near the paranosal sinuses cavities. The homogeneous phantom was a spherical glass balloon of 16 cm diameter, filled with MAGIC gel; i.e., the normoxic polymer gel. Two hollow PVC balls of 2 cm radius, filled with N{sub 2} gas, represented the air cavities inside the inhomogeneous phantom. For dose calibration purposes, 100 ml gel-containing vials were irradiated at predefined doses, and then scanned in a MR unit. Linearity was observed between the delivered dose and the reciprocal of the T2 relaxation time constant of the gel. Dose distributions are the results of a single shot of irradiation, obtained by collimating all 201 cobalt sources to a known target in the phantom. Both phantoms were irradiated at the same dose level at the same coordinates. Stereotactic frames and fiducial markers were attached to the phantoms prior to MR scanning. The dose distribution predicted by the Gamma Knife planning system was compared with that of the gel dosimetry. As expected, for the homogeneous phantom the isodose diameters measured by the gel dosimetry and the GammaPlan registered differed by 5% at most. However, with the inhomogeneous phantom, the dose maps in the axial, coronal and sagittal planes were spatially different. The diameters of the 50% isodose curves differed 43% in the X axis and 32% in the Y axis for the Z=90 mm axial plane; by 44% in the X axis and 24% in the Z axis for the Y=90 mm coronal plane; and by 32% in the Z axis and 42% in the Y axis for the X=92 mm sagittal plane. The lack of ability of the GammaPlan registered to predict the rapid dose fall off, due

  12. Single incision laparoscopic cholecystectomy: for what benefit?

    PubMed

    Tranchart, Hadrien; Ketoff, Serge; Lainas, Panagiotis; Pourcher, Guillaume; Di Giuro, Giuseppe; Tzanis, Dimitrios; Ferretti, Stefano; Dautruche, Antoine; Devaquet, Niaz; Dagher, Ibrahim

    2013-06-01

    A single-incision laparoscopic cholecystectomy (SILC) was developed to improve outcomes as compared with the four-port classic laparoscopic cholecystectomy (CLC). Any potential benefits associated with a SILC have been suggested by previous studies reporting few patients with different surgical techniques. The aim of this study was to describe the experience with a standardized SILC as compared with CLC. From June 2010 to January 2012, 40 patients underwent a SILC [median age: 47.5 years (25-92)] and operative and peri-operative data were prospectively collected. Over the same period, 37 patients underwent a CLC. A 10-point visual analogue scale (VAS) was used for qualitative data. The costs of SILC and CLC were also compared. For those patients undergoing a SILC the median operating time was 70 min (24-110). There were no conversions. An additional trocar was necessary in 16 patients. Four patients developed post-operative complications. The median immediate post-operative pain score was 5 (0-10). The median quality of life and cosmetic satisfaction at the initial post-operative visit were 10 (6-10) and 10 (5-10), respectively (VAS). Although the surgical results of both groups were similar, post-operative complications were exclusively reported in the SILC group (two incisional hernias). Standardization of SILC is possible but associated with an important rate of additional trocar placement and a disturbing rate of incisional hernias. © 2012 International Hepato-Pancreato-Biliary Association.

  13. [Diagnostic image (310). A man with a knife in his head].

    PubMed

    Beltman, J J; Wilde, J

    2007-02-10

    A 30-year-old man presented with a knife in his head; it had perforated the left temporal area and its point was located in the mouth. After surgical removal of the knife, the patient left the hospital without functional deficits.

  14. Removing seed coat fragments with a lint cleaner grid bar air knife

    USDA-ARS?s Scientific Manuscript database

    Seed coat fragments (SCF) in ginned lint cause spinning problems at the textile mill and undesirable defects in finished goods. Work continued on developing an air knife that may help remove SCF from ginned lint. The air knife is mounted on the 1st lint cleaner grid bar of a saw-type lint cleaner,...

  15. [Research progress of needles with knife-edge for carotid cardiac syndrome].

    PubMed

    Tan, Lingqiong; Zhao, Yanling

    2015-04-01

    According to topographic anatomy, pathogenesis and by retrieving, summarizing and analyzing literature regarding needle-knife and needles with knife-edge for carotid cardiac syndrome, it is found out that clinical misdiagnosis rate of carotid cardiac syndrome is considerably high. Needle-knife and needles with knife-edge could significantly improve the clinical symptoms of carotid cardiac syndrome, showing characteristic and advantage in treatment, but it is deficient in technique standard and efficacy criteria that should be united and authoritative. Researches regarding pathogenesis of carotid cardiac syndrome are not systematic. Clinical observation regarding long-term efficacy and relapse of needle-knife and needles with knife-edge treatment is rare. It is believed that the awareness on carotid cardiac syndrome should be increased to reduce misdiagnosis; scientific and standardized technique standard and efficacy criteria should be established; systematic and comprehensive researches regarding mechanism of needle-knife and needles with knife-edge for carotid cardiac syndrome should be launched; besides, clinical discussion regarding its long-term efficacy should start to provide a better clinical guideline.

  16. Relaxation Techniques for Health

    MedlinePlus

    ... for posttraumatic stress disorder have had inconsistent results. Rheumatoid Arthritis There’s limited evidence that biofeedback or other relaxation ... might be valuable additions to treatment programs for rheumatoid arthritis. Ringing in the Ears (Tinnitus) Only a few ...

  17. Relaxation techniques for stress

    MedlinePlus

    ... problems such as high blood pressure, stomachaches, headaches, anxiety, and depression. Using relaxation techniques can help you feel calm. These exercises can also help you manage stress and ease ...

  18. Geology of the Knife River area, North Dakota

    USGS Publications Warehouse

    Benson, William Edward

    1953-01-01

    The Knife River area, consisting of six 15-minute quadrangles, includes the lower half of the Knife River valley in west-central North Dakota. The area, in the center of the Williston Basin, is underlain by the Tongue River member of the Fort Union formation (Paleocene) and the Golden Valley formation (Eocene). The Tongue River includes beds equivalent to the Sentinel Butte shale; the Golden Valley formation, which receives its first detailed description in this report, consists of two members, a lower member of gray to white sandy kaolin clay and an upper member of cross-bedded micaceous sandstone. Pro-Tongue River rocks that crop out in southwestern North Dakota include the Ludlow member of the Fort Union formation, the Cannonball marine formation (Paleocene) and the Hell Creek, Fox Hills, and Pierre formations, all upper Cretaceous. Post-Golden Valley rocks include the White River formation (Oligocene) and gravels on an old planation surface that may be Miocene or Pliocent. Surficial deposits include glacial and fluvial deposits of Pleistocene age and alluvium, dune sand, residual silica, and landslide blocks of Recent age. Three ages of glacial deposits can be differentiated, largely on the basis of three fills, separated by unconformities, in the Knife River valley. All three are of Wisconsin age and probably represent the Iowan, Tazewell, and Mankato substages. Deposits of the Cary substage have not been identified either in the Knife River area or elsewhere in southern North Dakota. Iowan glacial deposits form the outermost drift border in North Dakota. Southwest of this border are a few scattered granite boulders that are residual from the erosion of either the White River formation or a pre-Wisconsin till. The Tazewell drift border cannot be followed in southern North Dakota. The Mankato drift border can be traced in a general way from the South Dakota State line northwest across the Missouri River and through the middle of the Knife River area. The major

  19. Neurological complications after gamma-knife radiosurgery for hypothalamic hamartoma.

    PubMed

    Butragueño Laiseca, Laura; Oikonomopoulou, Niki; Miranda Herrero, María Concepción; Barredo Valderrama, Estíbaliz; Vázquez López, María; Jiménez de Domingo, Ana; Aguado Del Hoyo, Alejandra; García-Leal, Roberto; Meiriño, Rosa M

    2016-09-01

    The Gamma-knife technique is a safe and effective option for the treatment of hypothalamic hamartomas that produce epileptic seizures refractory to medical treatment and/or serious behavioral disorders. After this type of radiosurgery, an adequate symptomatic control is normally achieved, with notable decrease or even disappearance of the seizures. Radiological changes, such as a decrease in the size of the tumor or adjacent edema secondary to non-necrotizing radioinduced inflammatory reaction are unusual consequences. Side effects and neurological complications are also rare events. This report describes an unusual case of complete radiological resolution of a hypothalamic hamartoma as well as neurological complications after Gamma-knife surgery (receiving 13 Gy to the 85% isodose line, 1 cm(3) of tumor volume) in a 8-year-old boy who suffered from severe refractory seizures. After radiosurgery, the patient experienced a notable improvement in his symptoms, achieving seizure cessation within 3 months. However, 4 months after the procedure he presented drowsiness, fever and decreased level of consciousness due to a direct effect on the hypothalamus with local and regional edema secondary to the radiosurgery that was performed. He was successfully treated with corticosteroids (with a total duration of 11 months), and twelve months after the surgery, complete disappearance of both the nodular lesion and the secondary edema was observed. The patient remains seizure-free in the last 16 months, with remarkable changes in his behavior. The present case shows that complete radiological resolution of a hypothalamic hamartoma after Gamma-knife technique is unusual but possible, without long-term neurological consequences. Nevertheless, despite its low incidence, if a patient presents neurological symptoms, primarily during the first year after intervention, possible complications of this type of surgery must be taken into account. Copyright © 2016 European Paediatric

  20. Gamma Knife Radiosurgery for Atypical and Anaplastic Meningiomas.

    PubMed

    Wang, Wei-Hsin; Lee, Cheng-Chia; Yang, Huai-Che; Liu, Kang-Du; Wu, Hsiu-Mei; Shiau, Cheng-Ying; Guo, Wan-You; Pan, David Hung-Chi; Chung, Wen-Yuh; Chen, Ming-Teh

    2016-03-01

    Atypical and anaplastic meningiomas have much higher recurrence rates after surgical resection compared with benign meningiomas, but the role of adjuvant radiosurgery remains unclear. This study was undertaken to evaluate the outcomes of gamma knife radiosurgery for patients with atypical and anaplastic meningiomas. In this retrospective analysis of a prospectively maintained database, 46 patients with histologically proven atypical or anaplastic meningiomas by current World Health Organization (WHO) criteria underwent postoperative Gamma Knife radiosurgery between 1993 and 2013. The median follow-up period was 32.6 months. The median tumor volume and margin dose were 11.7 mL (range, 2-53 mL) and 13.1 Gy (range, 12.0-16.5 Gy), respectively. Local control at 3 and 5 years was 50.6% and 32.1%, respectively. Gender (P = 0.013) and marginal dose less than or equal to 13 Gy (P = 0.049) were associated with the local control. The 3- and 5-year overall survival for patients with WHO grade II was 97.1% and 88.3%, respectively, compared with 66.7% and 66.7% for patients with WHO grade III meningiomas. Radiation therapy before Gamma Knife radiosurgery (GKRS; P = 0.018) and tumor grade (P = 0.019) were the factors associated with a worse overall survival rate. Fourteen patients (30.4%) developed adverse radiation effects after GKRS treatment, and all were Radiation Therapy Oncology Group grade I. Postoperative GKRS treatment for patients with atypical and anaplastic meningioma is challenging. More aggressive treatment, including of safely maximizing the extent of surgical resection and using a higher margin dose (>13Gy), should be applied to achieve better local control. Copyright © 2016 Elsevier Inc. All rights reserved.

  1. PRESAGE 3D dosimetry accurately measures Gamma Knife output factors

    NASA Astrophysics Data System (ADS)

    Klawikowski, Slade J.; Yang, James N.; Adamovics, John; Ibbott, Geoffrey S.

    2014-12-01

    Small-field output factor measurements are traditionally very difficult because of steep dose gradients, loss of lateral electronic equilibrium, and dose volume averaging in finitely sized detectors. Three-dimensional (3D) dosimetry is ideal for measuring small output factors and avoids many of these potential challenges of point and 2D detectors. PRESAGE 3D polymer dosimeters were used to measure the output factors for the 4 mm and 8 mm collimators of the Leksell Perfexion Gamma Knife radiosurgery treatment system. Discrepancies between the planned and measured distance between shot centers were also investigated. A Gamma Knife head frame was mounted onto an anthropomorphic head phantom. Special inserts were machined to hold 60 mm diameter, 70 mm tall cylindrical PRESAGE dosimeters. The phantom was irradiated with one 16 mm shot and either one 4 mm or one 8 mm shot, to a prescribed dose of either 3 Gy or 4 Gy to the 50% isodose line. The two shots were spaced between 30 mm and 60 mm apart and aligned along the central axis of the cylinder. The Presage dosimeters were measured using the DMOS-RPC optical CT scanning system. Five independent 4 mm output factor measurements fell within 2% of the manufacturer’s Monte Carlo simulation-derived nominal value, as did two independent 8 mm output factor measurements. The measured distances between shot centers varied by ±0.8 mm with respect to the planned shot displacements. On the basis of these results, we conclude that PRESAGE dosimetry is excellently suited to quantify the difficult-to-measure Gamma Knife output factors.

  2. Cyclic steps incised on experimental bedrock

    NASA Astrophysics Data System (ADS)

    Yokokawa, M.; Kyogoku, A.; Kotera, A.; Izumi, N.

    2013-12-01

    the step shape has been predicted by the mathematical model (Izumi et al., 2012). Among three cases of sediment supply: 1 g/sec, 3 g/sec, and 6 g/sec with fixed water discharge (52 g/sec), the erosion rate was maximized in the cases of the sediment supply of 3 g/sec both in the cement-sand-water ratios of 2:150:50 and 3:150:50. The erosion rate is higher in the case of the moderate amount of sediment supply rather than in the case of the largest amount of sediment supply in which the alluvial cover effect inhibited erosion. This result is consistent with that observed in previous studies (Sklar & Dietrich, 2004; Johnson & Whipple, 2010). References Izumi, N., Yokokawa, M. & Parker G. 2012. Cyclic step morphology formed on bedrock. Annual Journal of Hydraulic Engineering 68(4) : I_955-I_960. Johnson, J.P.L. & Whipple, K.X. 2010. Evaluating the controls of shear stress, sediment supply, alluvial cover, and channel morphology on experimental bedrock incision rate. Journal of Geophysical Research 115, F02018, doi:10.1029/2009JF001335. Sklar, L.S. & Dietrich, W.E. 2004. A mechanistic model for river incision into bedrock by sultating bedload. Water Resources Re-search 40, W06301, doi:10.1029/2003WR002496.

  3. Single-incision laparoscopic management of a giant hepatic cyst.

    PubMed

    Willems, Kaitlin; Monsivais, Sharon; Vassaur, Hannah; Buckley, Francis P

    2015-07-29

    Large symptomatic hepatic cysts may warrant surgical management. Traditional multiport laparoscopic technique is typically preferred over open laparotomy, but the use of the single-incision laparoscopic approach for this diagnosis is not well documented. Here, we describe the case of a 68-year-old woman who underwent complete anterior wall fenestration, excision and cauterization of a simple hepatic cyst via a single-incision laparoscopic technique through an incision at the umbilicus. The objective of this case report is to document single-incision laparoscopy as a safe, feasible and cosmetically appealing approach for the management of a large hepatic cyst. Published by Oxford University Press and JSCR Publishing Ltd. All rights reserved. © The Author 2015.

  4. MCNP-based computational model for the Leksell Gamma Knife

    SciTech Connect

    Trnka, Jiri; Novotny, Josef Jr.; Kluson, Jaroslav

    2007-01-15

    We have focused on the usage of MCNP code for calculation of Gamma Knife radiation field parameters with a homogenous polystyrene phantom. We have investigated several parameters of the Leksell Gamma Knife radiation field and compared the results with other studies based on EGS4 and PENELOPE code as well as the Leksell Gamma Knife treatment planning system Leksell GammaPlan (LGP). The current model describes all 201 radiation beams together and simulates all the sources in the same time. Within each beam, it considers the technical construction of the source, the source holder, collimator system, the spherical phantom, and surrounding material. We have calculated output factors for various sizes of scoring volumes, relative dose distributions along basic planes including linear dose profiles, integral doses in various volumes, and differential dose volume histograms. All the parameters have been calculated for each collimator size and for the isocentric configuration of the phantom. We have found the calculated output factors to be in agreement with other authors' works except the case of 4 mm collimator size, where averaging over the scoring volume and statistical uncertainties strongly influences the calculated results. In general, all the results are dependent on the choice of the scoring volume. The calculated linear dose profiles and relative dose distributions also match independent studies and the Leksell GammaPlan, but care must be taken about the fluctuations within the plateau, which can influence the normalization, and accuracy in determining the isocenter position, which is important for comparing different dose profiles. The calculated differential dose volume histograms and integral doses have been compared with data provided by the Leksell GammaPlan. The dose volume histograms are in good agreement as well as integral doses calculated in small calculation matrix volumes. However, deviations in integral doses up to 50% can be observed for large

  5. Differential stream incision in the Oregon Coast Range

    SciTech Connect

    Personius, S.F. )

    1993-04-01

    Stream incision rates are used to determine rates and styles of late quaternary deformation of the Oregon Coast Range, in the forearc of the Cascadia subduction zone. Bedrock incision rates were obtained along westward-flowing streams, from the Umpqua river in a central western Oregon to the North Fork Nehalem River in northwestern Oregon. Incision measurements were restricted mostly to nontidal reaches that are more than 20--40 km inland from the coast, to exclude areas affected by eustatic changes in sea level. Most strath ages were determined indirectly by radiocarbon dating of detrital charcoal sampled from alluvium that overlies the straths. A few incision measurements were made on straths that underlie higher, less well preserved terrace remnants. The ages of some of these higher straths were determined by thermoluminescence (TL) dating. These ages are less constrained than those established with radiocarbon dating, but they appear to yield similar rates of incision. The difference in age between the overlying sediments and the age of strath abandonment is unknown, but several lines of evidence indicate that sediment mobilization and deposition most likely were concurrent with cutting of the strath. Numerous strath height measurements indicate that rates of incision are fairly uniform along many kilometers of individual Coast Range streams, regardless of the type of bedrock traversed. Such uniform incision rates do not support the landward tilting of the Coast Range as postulated by other studies. However, regional differences in incision apparent in northern Oregon may be explained by differential uplift caused by north-south compression in the overriding North American plate, or by changes in the geometry of the subducting Juan de Fuca plate.

  6. Landscape evolution due to river incision in active mountains

    NASA Astrophysics Data System (ADS)

    Lavé, L.; Attal, A.

    2003-04-01

    It is commonly accepted that fluvial network incision control the local base level for hillslopes and therefore controls the rate of landscape denudation, and thus the way the landscape will respond to tectonic or climatic forcings. For that reason, many studies have focused for the last ten years in quantifying fluvial incision rates and the mechanisms of fluvial incision into bedrock. In many morphotectonic settings the shear stress model has been widely used and provided satisfactory first order description of the river incision in active mountains. Across the Siwaliks range in front of the Himalaya, the shear stress model (that also includes bedload mean pebble size and explicit channel width variations), provides a good proxy to estimate incision and uplift rate, that can be measured independently from fluvial terraces studies. By transposition and after calibration to more resistant crystalline lithologies, this model helped to define the incision rate profiles across the whole Himalayan ranges. These profiles were found coherent with current seismotectonic model, sediment budget, fluvial terrace studies and geochronology results. More importantly, the incision model was found to provide good results in two other active regions: across the Nanga Parbat massif in Pakistan, and in the San Gabriel Ranges in California, with only minor required changes of the erodibility coefficient despite very different hydroclimatic setting. However, this semi-empirical model is not mechanically satisfying: in many settings, river bedload fluxes exert an important control on incision rates, by limiting bedrock exposure or by providing an efficient tool for river mechanical abrasion. A reappraisal of the former examples as thus conducted in order to test different models including the role of sediment fluxes. General results and models will be first discussed in light of their physical consistency with field and experimental data on pebble and bedrock abrasion, and second in

  7. Calcaneal Fracture Management: Extensile Lateral Approach Versus Small Incision Technique.

    PubMed

    Kiewiet, Nathan J; Sangeorzan, Bruce J

    2017-03-01

    Calcaneal fracture management has historically been a controversial topic and represents an area of sustained interest over the past several decades. The authors review current methods for calcaneal fracture fixation with an extensile lateral approach and small incision techniques. Early reports of small incision techniques have reported promising outcomes and reduced risks for complications. These techniques may be beneficial to reduce the risk of soft tissue complications and improve the rate of recovery.

  8. Orchiopexy through a single high transverse scrotal incision

    PubMed Central

    Khirallah, Mohammad G.; Elafifi, Mahmoud A.; Elbatarny, Akram M.; Elsharaby, Ahmed M.

    2015-01-01

    Background: Palpable Undescended Testis (PUT) represents a common paediatric problem in many premature and some mature infants. There are several surgical techniques to correct PUT either through combined inguinal and scrotal incision or single transverse scrotal incision. This study assessed single high transverse scrotal incision for the management of PUT as regards to feasibility, postoperative success and final cosmetic results. Materials and Methods: One hundred twenty patients were managed at the Paediatric Surgery Department of Tanta University Hospital with PUT during the period from March 2010 to March 2014. They were all operated at the age of 6-12 months. We excluded recurrent cases, and cases older than 12 months. Through high transverse scrotal incision, the layers were divided, and the canal entered through the external ring, dissecting the PUT and bringing it through the incision. Hernia sac, if present, was ligated at the neck. Creation of the dartos pouch was then made through the same incision. All infants were followed-up at 1 month, 2 months and 6 months to detect any re-ascended cases, testicular atrophy and the final cosmetic appearance. Results: A total of 140 PUTs were operated upon in 120 patients. PUT was bilateral in 20 patients, right-sided in 65 cases and left-sided in 35 cases. Thirty testes were located at the external ring; the others were located within the inguinal canal. No cases needed a redo operation, and there was no case of postoperative testicular atrophy. Conclusion: Single high transverse incision was sufficient to deal with PUT especially, in young infants (age 6 months) with no need for conversion in most cases to the traditional two incisions technique, and good long term follow-up and a better cosmetic results. PMID:25659553

  9. Water table fluctuations near an incised stream, Walnut Creek, Iowa

    USGS Publications Warehouse

    Schilling, K.E.; Zhang, Y.-K.; Drobney, P.

    2004-01-01

    Incised channels are common features in many agricultural watersheds, but the effects of channel incision on riparian water table conditions have been poorly documented. In this study, we evaluate the water table fluctuations in the floodplain near an incised stream (Walnut Creek, Iowa) and investigate the roles that channel incision and variable recharge play in modifying the water table configuration in the floodplain. Groundwater flows from higher landscape positions towards Walnut Creek under hydraulic gradients that were steepest near the upland/floodplain contact and in the near-stream riparian zone. Annually, water table fluctuations on the floodplain were greatest in wells located 30 m from the creek, midway between the creek and upland. Water levels monitored continuously during a runoff event indicated that bank storage was confined to a narrow zone adjacent to the channel. A steady-state, one-dimensional analytical model was developed to describe the shape of the water table surface near an incised stream and evaluate how variable groundwater recharge and channel bed lowering has affected the shape of the water table surface. Results from this study have implications for managing the riparian buffers of incised streams with successful establishment dependent upon matching buffer vegetation to riparian water table conditions. ?? 2003 Elsevier B.V. All rights reserved.

  10. A geometric analysis of mastectomy incisions: Optimizing intraoperative breast volume

    PubMed Central

    Chopp, David; Rawlani, Vinay; Ellis, Marco; Johnson, Sarah A; Buck, Donald W; Khan, Seema; Bethke, Kevin; Hansen, Nora; Kim, John YS

    2011-01-01

    INTRODUCTION: The advent of acellular dermis-based tissue expander breast reconstruction has placed an increased emphasis on optimizing intraoperative volume. Because skin preservation is a critical determinant of intraoperative volume expansion, a mathematical model was developed to capture the influence of incision dimension on subsequent tissue expander volumes. METHODS: A mathematical equation was developed to calculate breast volume via integration of a geometrically modelled breast cross-section. The equation calculates volume changes associated with excised skin during the mastectomy incision by reducing the arc length of the cross-section. The degree of volume loss is subsequently calculated based on excision dimensions ranging from 35 mm to 60 mm. RESULTS: A quadratic relationship between breast volume and the vertical dimension of the mastectomy incision exists, such that incrementally larger incisions lead to a disproportionally greater amount of volume loss. The vertical dimension of the mastectomy incision – more so than the horizontal dimension – is of critical importance to maintain breast volume. Moreover, the predicted volume loss is more profound in smaller breasts and primarily occurs in areas that affect breast projection on ptosis. CONCLUSIONS: The present study is the first to model the relationship between the vertical dimensions of the mastectomy incision and subsequent volume loss. These geometric principles will aid in optimizing intra-operative volume expansion during expander-based breast reconstruction. PMID:22654531

  11. Posterosuperior extension of caudal septal incision for endoscopic septoplasty.

    PubMed

    Kim, Sang-Wook; Joo, Yeon-Hee; Jeon, Sea-Yuong

    2015-10-01

    Endoscopic septoplasty provides several advantages over traditional headlight septoplasty in terms of better visualization. However, surgeons may experience frequent soiling of the endoscope lens by blood from the incision site and awkwardness in finding adequate space for the endoscope and dissectors in narrow septal mucosal tunnels. Here, we propose a simple and safe modification for endoscopic septoplasty. A total of 21 patients underwent endoscopic septoplasty using a new modification. Briefly, a posterosuperior extension incision was made along the dorsal septum at the superior end of the caudal septal incision, and a posteroinferior-based septal mucosal flap was developed and placed laterally over the inferior turbinate during surgery. The new modification reported here provided clear endoscopic visualization and a comfortable working space from making the incision to closing the wound. In addition, no significant complications related to this modification, such as increased operation time, intraoperative or postoperative bleeding, delayed wound healing, synechia, nasal septal perforation, and reduced olfaction, were observed. Adding a posterosuperior extension incision to the caudal septal incision might be a safe and efficient modification for endoscopic septoplasty. © 2015 ARS-AAOA, LLC.

  12. Periareolar incision for the management of benign breast tumors.

    PubMed

    Kong, Xiangnan; Chen, Xi; Jiang, Liyu; Ma, Tingting; Han, Baosan; Yang, Qifeng

    2016-11-01

    Benign breast tumors (BBTs) are common in women. The traditional surgical resection method for the various types of BBT leaves obvious scars and affects the appearance of the breast. The present study introduces the experience of a single institution in the treatment of BBT by periareolar incision. The clinical data of 153 patients (182 breasts) with BBT who had undergone a resection via a periareolar incision between January 2010 and December 2012 in Qilu Hospital, Shandong University (Jinan, Shandong, China), was retrospectively analyzed. All incisions were primary healing. Of the 153 patients, 1 (0.7%) developed a hematoma and 2 (1.3%) developed slight nipple ischemia. No infections or other complications were observed. During 1 month to 3 years of follow-up, the cosmetic effects were assessed. Periareolar incision is not only suitable for all types of breast surgery for benign tumor resection, but also has the advantage of a hidden incision, a small scar, no ischemic necrosis of the nipple areola, high patient satisfaction and good post-operative cosmetic effect. The technique is therefore a good surgical incision choice that is worthy of note.

  13. Evaluation of tissue adhesives in closure of scleral tunnel incisions.

    PubMed

    Kim, J C; Bassage, S D; Kempski, M H; del Cerro, M; Park, S B; Aquavella, J V

    1995-05-01

    Using a biomechanical wound strength model, we compared the efficacy of cyanoacrylate and fibrin glues used to close scleral tunnel incisions. Scleral tunnel incisions were made in four groups of rabbits: (1) traditional self-sealing incision, (2) modified non-self-sealing incision, (3) method 2, closed with cyanoacrylate glue, or (4) method 2, closed with fibrin glue. Overall, Groups 1 and 4 showed the least clinical reaction, the slightest decrease in intraocular pressure (which recovered to baseline by day 7), and the most significant recovery of postoperative astigmatism. Initially, the bursting pressure in Groups 1 and 3 was statistically the highest (P < .005). By day 3, wound strengths in Groups 1 and 4 were comparable. Bursting pressure decreased in Groups 2 and 3 by day 7. Our results indicate that clinical responses, intraocular pressure, induced astigmatism, and ultimately wound strength were comparable in fibrin-glue-closed scleral pocket and sutureless self-sealing cataract incisions. Although cyanoacrylate glue cures immediately and initially demonstrates a strong adhesive quality, it causes a severe inflammatory response that inhibits subsequent collagen remodeling. Fibrin tissue adhesives may have an application as adjunctive means of closing scleral tunnel incisions.

  14. Periareolar incision for the management of benign breast tumors

    PubMed Central

    Kong, Xiangnan; Chen, Xi; Jiang, Liyu; Ma, Tingting; Han, Baosan; Yang, Qifeng

    2016-01-01

    Benign breast tumors (BBTs) are common in women. The traditional surgical resection method for the various types of BBT leaves obvious scars and affects the appearance of the breast. The present study introduces the experience of a single institution in the treatment of BBT by periareolar incision. The clinical data of 153 patients (182 breasts) with BBT who had undergone a resection via a periareolar incision between January 2010 and December 2012 in Qilu Hospital, Shandong University (Jinan, Shandong, China), was retrospectively analyzed. All incisions were primary healing. Of the 153 patients, 1 (0.7%) developed a hematoma and 2 (1.3%) developed slight nipple ischemia. No infections or other complications were observed. During 1 month to 3 years of follow-up, the cosmetic effects were assessed. Periareolar incision is not only suitable for all types of breast surgery for benign tumor resection, but also has the advantage of a hidden incision, a small scar, no ischemic necrosis of the nipple areola, high patient satisfaction and good post-operative cosmetic effect. The technique is therefore a good surgical incision choice that is worthy of note. PMID:27899991

  15. Influence of Incision Location on Transmitter Loss, Healing, Incision Lengths, Suture Retention, and Growth of Juvenile Chinook Salmon

    DTIC Science & Technology

    2010-05-01

    analysis. Dennis Dauble , Brian Miller, Katie Panther, John Panther, and Virginia Panther provided much scientific advice. Final Report vii...represented the proportion of the incision that was apposed, folding inward, overlapping, and/or gaping apart. Similar to Wynne et al. (2004), apposition...grade external appearance of tissue apposition of incision. A) Eight possible outcomes of apposition (apposed, folding inward, some portion overlapping

  16. A randomised controlled trial of mini incision or conventional incision for saphenous vein harvesting in patients undergoing myocardial revascularization

    PubMed Central

    Gontijo de Deus, Kleber; Diogo Filho, Augusto; Cesar Santos, Paulo

    2016-01-01

    Objective Compare the evolution regarding the complications concerning two types of incision (conventional × mini-incision), for saphenectomy in patients that go under myocardial revascularization or otherwise known as coronary artery bypass surgery. Methods In January 2012 to August 2013, 66 patients were prospectively selected for coronary artery bypass with cardiopulmonary bypass surgery. These were divided into two groups: Conventional and Mini-Incision, with 33 patients in each group chosen in a random fashion and with knowledge of which technique to be used being presented only at the start of the surgery. In the conventional group, the patients received an incision to the lower member of 7–10 cm. The patients in the Mini-Incision group received an incision to the lower member of 3–4 cm, both performed without the use of any special material. Results The groups were similar in terms of clinical data and in the preoperative period. Males made up a greater part of the group with 63.7% and 81.9% in groups C and M, respectively. Among the complications analysed, edema (p = 0.011), hematoma (p = 0.020), dehiscence (p = 0.012) and infection (p = 0.012), were significantly greater in group C when compared to group M. When the matter comes to the variable in relation to the risk of Surgical Site Infections (SSI), no difference was found between the groups. Conclusion Coronary artery bypass surgery with mini-incision for saphenectomy, demonstrated a lower rate for preoperative complications when compared to saphenectomy under conventional incision procedures. PMID:27006766

  17. Fluvial incision into bedrock: Insights from morphometric analysis and numerical modeling of gorges incising glacial hanging valleys (Western Alps, France)

    NASA Astrophysics Data System (ADS)

    Valla, Pierre G.; van der Beek, Peter A.; Lague, Dimitri

    2010-06-01

    Bedrock gorges incising glacial hanging valleys potentially allow measurements of fluvial bedrock incision in mountainous relief. Using digital elevation models, topographic maps, and field reconnaissance, we identified and characterized 30 tributary hanging valleys incised by gorges near their confluence with trunk streams in the Romanche watershed, French Western Alps. Longitudinal profiles of these tributaries are all convex and have abrupt knickpoints at the upper limit of oversteepened gorge reaches. We reconstructed initial glacial profiles from glacially polished bedrock knobs surrounding the gorges in order to quantify the amount of fluvial incision and knickpoint retreat. From morphometric analyses, we find that mean channel gradients and widths, as well as knickpoint retreat rates, display a drainage area dependence modulated by bedrock lithology. However, there appears to be no relation between horizontal retreat and vertical downwearing of knickpoints. Assuming a postglacial origin of these gorges, our results imply high postglacial fluvial incision (0.5-15 mm yr-1) and knickpoint retreat (1-200 mm yr-1) rates that are, however, consistent with previous estimates. Numerical modeling was used to test the capacity of different fluvial incision models to predict the inferred evolution of the gorges. Results from simple end-member models suggest transport-limited behavior of the bedrock gorges. A more sophisticated model including dynamic width adjustment and sediment-dependent incision rates predicts present-day channel geometry only if a significant supply of sediment from the gorge sidewalls (˜10 mm yr-1) is triggered by gorge deepening, combined with pronounced inhibition of bedrock incision by sediment transport and deposition.

  18. Anterior capsulotomy with a pulsed-electron avalanche knife

    PubMed Central

    Palanker, Daniel; Nomoto, Hiroyuki; Huie, Philip; Vankov, Alexander; Chang, David F.

    2009-01-01

    PURPOSE To evaluate a new pulsed-electron avalanche knife (PEAK) design for creating a continuous curvilinear capsulorhexis (CCC) and compare the CCC with a mechanical capsulorhexis. SETTING Department of Ophthalmology, Stanford University, Stanford, California, USA. METHODS In this study, CCCs were created in freshly enucleated bovine eyes and in rabbit eyes in vivo. The cutting velocity was adjusted by controlling the burst repetition rate, voltage amplitude, and burst duration. Tissue samples were fixed and processed for histology and scanning electron microscopy (SEM) immediately after surgery. RESULTS The study included 50 bovine eyes and 10 rabbit eyes. By adjusting the electrosurgical waveforms, gas-bubble formation was minimized to permit good surgical visualization. The optimum voltage level was determined to be ±410 V with a burst duration of 20 μs. Burst repetition rate, continuously adjustable from 20 to 200 Hz with footpedal control, allowed the surgeon to vary linear cutting velocity up to 2.0 mm/second. Histology and SEM showed that the pulsed-electron avalanche knife produced sharp-edged capsule cutting without radial nicks or tears. CONCLUSIONS The pulsed-electron probe duplicated the surgical feel of a 25-gauge cystotome and created a histologically smooth capsule cut. PMID:20117716

  19. GammaKnife surgery: safety and the identity of users.

    PubMed

    Dinka, David; Nyce, James M; Timpka, Toomas

    2005-01-01

    In this study we investigated safety-related usability issues of an advanced medical technology, a radiosurgery system. We were interested in which criteria are important for users when a system's usability and safety is to be improved. The data collection was based on interviews and observations at three different sites where the Leksell GammaKnife is used. The analysis was qualitative. The main finding was that the user's identity or professional background has a significant impact both on how he or she views his or her role in the clinical setting, and on how he or she defines what improvements are necessary and general safety issues. In fact, the opinion even of users experienced in safety-related problems was highly influenced by how they related to the technology and its development. None of the users actually considered Leksell GammaKnife as lacking in safety, instead, their assessment was directed towards potential future system improvements. Our findings suggest that the importance of user identity or professional background cannot be neglected during the development of advanced technology. They also suggest that the user feedback should always be related to user background and identity in order to understand how important different issues are for particular users.

  20. Dosimetrical evaluation of Leksell Gamma Knife 4C radiosurgery unit

    NASA Astrophysics Data System (ADS)

    Sajeev, Thomas; Mustafa, Mohamed M.; Supe, Sanjay S.

    2011-01-01

    A number of experiments was performed using standard protocols, in order to evaluate the dosimetric accuracy of Leksell Gamma Knife 4C unit. Verification of the beam alignment has been performed for all collimators using solid plastic head phantom and Gafchromic™ type MD-55 films. The study showed a good agreement of Leksell Gammaplan calculated dose profiles with experimentally determined profiles in all three axes. Isocentric accuracy is verified using a specially machined cylindrical aluminium film holder tool made with very narrow geometric tolerances aligned between trunnions of 4 mm collimator. Considering all uncertainties in all three dimensions, the estimated accuracy of the unit was 0.1 mm. Dose rate at the centre point of the unit has been determined according to the IAEA, TRS-398 protocol, using Unidose-E (PTW-Freiburg, Germany) with a 0.125 cc ion chamber, over a period of 6 years. The study showed that the Leksell Gamma Knife 4C unit is excellent radiosurgical equipment with high accuracy and precision, which makes it possible to deliver larger doses of radiation, within the limits defined by national and international guidelines, applicable for stereotactic radiosurgery procedures.

  1. Incision History of the Black Canyon of the Gunnison

    NASA Astrophysics Data System (ADS)

    Sandoval, M.; Karlstrom, K. E.; Aslan, A.; Kirby, E.; Granger, D.

    2006-12-01

    The Gunnison River is the major tributary of the Colorado River that drains some of the highest topography of the Colorado Rocky Mountains. Paleo river profiles at 640ka, 10Ma, and ~35Ma provide benchmarks to understand the long-term incision history of the Black Canyon. Reconstruction of these paleo profiles is based on elevated bedrock straths and alluvial deposits that can be dated using the Lava Creek B ash (640 ka), Grand Mesa and associated basalts (10 Ma), and Oligocene ash flow tuffs (~35 Ma). Comparison of these to the modern profile offers insight into incision history. The modern long profile displays a distinct knickpoint located near the Painted Wall in the Black Canyon of the Gunnison National Park. This high-gradient reach (10-km-long) is partly explained by the Vernal Mesa Granite, but it traverses basement lithologies present above and below the knickpoint, suggesting that increased river gradient is not explained entirely by hard bedrock. Incision rates downstream of the knickpoint are higher (250-300 m/Ma over 640 ka and ~ 150 m/Ma over 10 Ma) in comparison to upstream rates (140 m/Ma over 640 ka and ~ 150 m/Ma over 10 Ma). The difference in incision rates across the knickpoint argue that this feature reflects transient adjustment of the fluvial system to baselevel lowering associated with downstream drainage reorganization. Incision rates in the nearby reaches of the Colorado River since 1-3 Ma are distinctly higher than those in the time periods of ~30 Ma- present and 10 Ma-present. This leads us to infer that rapid incision was not established in the Gunnison region until post ca. 3 Ma. A knickpoint similar to that seen in the modern profile is present in the reconstructed 640ka profile, reinforcing the transient character and implying upstream migration of the knickpoint of 25km in the past 640 ka. Projection of the ~ 640 ka river gravels in the abandoned Shinn- Bostwick tributary to its intersection with the Gunnison at Red Canyon is

  2. Endoscopic treatment for pancreatic diseases: Needle-knife-guided cannulation via the minor papilla

    PubMed Central

    Wang, Wei; Gong, Biao; Jiang, Wei-Song; Liu, Lei; Bielike, Kouken; Xv, Bin; Wu, Yun-Lin

    2015-01-01

    AIM: To determine the efficacy and safety of meticulous cannulation by needle-knife. METHODS: Three needle-knife procedures were used to facilitate cannulation in cases when standard cannulation techniques failed. A total of 104 cannulations via the minor papilla attempted in 74 patients at our center between January 2008 and June 2014 were retrospectively reviewed. RESULTS: Standard methods were successful in 79 cannulations. Of the 25 cannulations that could not be performed by standard methods, 19 were performed by needle-knife, while 17 (89.5%) were successful. Needle-knife use improved the success rate of cannulation [76.0%, 79/104 vs 92.3%, (79 + 17)/104; P = 0.001]. When the 6 cases not appropriate for needle-knife cannulation were excluded, the success rate was improved further (80.6%, 79/98 vs 98.0%, 96/98; P = 0.000). There were no significant differences in the rates of post-endoscopic retrograde cholangiopancreatography adverse events between the group using standard methods alone and the group using needle-knife after failure of standard methods (4.7% vs 10.5%, P = 0.301). CONCLUSION: The needle-knife procedure may be an alternative method for improving the success rate of cannulation via the minor papilla, particularly when standard cannulation has failed. PMID:26019460

  3. Unusual clinical case: extraluminal manifestation of a tapeworm from the eviscerated midline incision in a post-surgery patient.

    PubMed

    Dural, Ahmet Cem; Celik, Muhammet Ferhat; Temizgonul, Baha; Unsal, Mustafa Gokhan; Akarsu, Cevher; Gonenc, Murat; Kalayci, Mustafa Uygar; Alis, Halil

    2015-04-15

    Taenia saginata infestation is one of the most common cestode infestations in humans, that may cause gastrointestinal tract related complications as a result of obstruction, perforation or anastomotic leakage. A 55-year-old male patient who was receiving palliative chemotherapy for stage IV gastric cancer was admitted to the emergency department for abdominal pain. A hollow viscus organ perforation was diagnosed and an emergency surgery was performed. On postoperative day 5, the patient's midline incision eviscerated and a moving taenia emerged, with abundant particulated fluid from the incision line. The patient was admitted for abdominal surgery due to suspected bowel perforation. During the abdominal exploration, a relaxed purse stitch of the feeding tube was observed and no other bowel perforations were seen. The patient underwent two planned surgery for abdominal cavity lavage after the removal of cestode. Unfortunately, the patient died sixteen days after his admission to the intensive care unit. This is the first case describing an extraluminal manifestation of a tapeworm in a midline incision from evisceration without intestinal perforation.

  4. Novel design and sensitivity analysis of displacement measurement system utilizing knife edge diffraction for nanopositioning stages.

    PubMed

    Lee, ChaBum; Lee, Sun-Kyu; Tarbutton, Joshua A

    2014-09-01

    This paper presents a novel design and sensitivity analysis of a knife edge-based optical displacement sensor that can be embedded with nanopositioning stages. The measurement system consists of a laser, two knife edge locations, two photodetectors, and axillary optics components in a simple configuration. The knife edge is installed on the stage parallel to its moving direction and two separated laser beams are incident on knife edges. While the stage is in motion, the direct transverse and diffracted light at each knife edge is superposed producing interference at the detector. The interference is measured with two photodetectors in a differential amplification configuration. The performance of the proposed sensor was mathematically modeled, and the effect of the optical and mechanical parameters, wavelength, beam diameter, distances from laser to knife edge to photodetector, and knife edge topography, on sensor outputs was investigated to obtain a novel analytical method to predict linearity and sensitivity. From the model, all parameters except for the beam diameter have a significant influence on measurement range and sensitivity of the proposed sensing system. To validate the model, two types of knife edges with different edge topography were used for the experiment. By utilizing a shorter wavelength, smaller sensor distance and higher edge quality increased measurement sensitivity can be obtained. The model was experimentally validated and the results showed a good agreement with the theoretically estimated results. This sensor is expected to be easily implemented into nanopositioning stage applications at a low cost and mathematical model introduced here can be used for design and performance estimation of the knife edge-based sensor as a tool.

  5. Neural outcomes after plasma knife dissection: a pathologic study and clinical correlation.

    PubMed

    Gillespie, M Boyd; Stachiw, Natalka D; Way, Justin; Lentsch, Eric J; Richardson, Mary S; Nguyen, Shaun A; Day, Terry A; Hornig, Joshua D

    2010-10-01

    The initial aim was to determine the rate of pathologic tissue damage when dissecting the rat sciatic nerve with either bipolar forceps or low-temperature tripolar plasma knife. The second aim was to determine the safety and effectiveness of the plasma knife during parotid surgery. A prospective, randomized, single-blind study was performed on 40 rat sciatic nerves dissected by either bipolar electrocautery with a cold knife or a plasma knife. Dissected nerves were excised and submitted blindly to pathology for analysis of nerve injury. The degree of nerve trauma was graded by the Carlander nerve injury classification. Separately, a review was performed on the facial nerve outcomes of 30 patients who underwent plasma knife parotidectomy. No thermal or neural injury was noted in the 40 rat sciatic nerves dissected by either bipolar electrocautery or plasma knife (p = 1.0). Two plasma knife-dissected nerves (8%) demonstrated significant numbers of mast cells in the perineural soft tissue. In 30 patients undergoing plasma knife-parotidectomy, 10 (33%) had mild weakness of 1 or 2 preserved facial nerve branch postoperatively (House-Brackmann 2) that resolved within 1 month, whereas 2 (7%) had visible weakness in 1 branch (HB 3) that normalized after 3 months of follow-up. Plasma knife nerve dissection seems to be a safe and effective alternative to conventional methods. This technique may confer some advantages over conventional methods with the ability to simultaneously cut and coagulate tissue with minimal thermal spread and electrical stimulation of adjacent neural structures. © 2010 Wiley Periodicals, Inc.

  6. Retroauricular hairline incision for removal of upper neck masses.

    PubMed

    Roh, Jong-Lyel

    2005-12-01

    The general population has been increasingly concerned about cosmesis and hopeless about prominent or invisible postoperative scars of the face and neck. The purpose of this study was to evaluate the benefit of a retroauricular hairline incision (RAHI) by comparing it with conventional cervical incision for removal of upper neck masses. Prospective clinical study. Thirty-four patients with upper neck masses were divided into two surgical groups of RAHI (17) and conventional cervical incision (17) matched by age, sex, marital status and size, location, pathology of lesions. The operation time, complications, length of hospital stay, and subjective satisfaction with incision scar checked by visual analogue scale were compared between groups. The lesions of each group were congenital cysts (6), abscesses (2), inflammatory masses (2), and benign (6) or malignant (1) tumors and located in the upper neck. Mean operation time was 51 +/- 17 minute in the RAHI group and 41 +/- 13 minutes in the controls (P = .064). Mean hospital stay and complication rates were comparable between groups. Mean score of patient's satisfaction was 8.9 +/- 0.7 in the RAHI group and 4.5 +/- 2.7 in the controls (P < .001). The degree of incision scarring did not differ between groups, but the scars were less visible in the RAHI group because of hiding by the auricle and hair. The postauricular approach leading to a potentially invisible area of operation has a clear cosmetic benefit compared with conventional cervical incision. This will be helpful for patients with surgically indicated upper neck masses who hope for invisible incision scars.

  7. Face lifts with hidden scars: the vertical U incision.

    PubMed

    Marchac, Daniel; Brady, James A; Chiou, Portia

    2002-06-01

    The authors present their latest development of a strictly vertical retroauricular incision to minimize a sequela of a face lift, namely, a visible scar. The temporal preauricular vertical incision and the retroauricular vertical incision form two parallel arms of a U-shaped incision. Anteriorly, a downward rotation flap is made to maintain the horizontal temporal line at the right level, and posteriorly, the scalp is incised vertically, followed by extensive superficial retroauricular undermining. In both temporal and retroauricular areas, skin and scalp undergo a redistribution rather than resection, which is extremely limited. The authors' experience with 100 patients who were operated on with vertical U incisions since April of 2000 is described. A total of 35 patients were evaluated after a 6-month follow-up by using clinical and photographic examinations. There were very few complications because the extensive retroauricular flap has good viability. There were no problems with sensitivity, hair loss, or scar spreading, and the hairline was not displaced. The quality of the scar was excellent in the majority of cases. We experienced only a few hypertrophic but well-hidden scars. This approach can also be used in secondary cases when the primary scar is of good quality. The neck pull is as effective as that in the classic approach with a traverse retroauricular incision. The nondetectability of the retroauricular scar is of special interest in young patients and in men. The authors believe there is no contraindication for this technique. It does not significantly prolong the operating time. It includes a large undermining in the retroauricular area (6 cm from the sulcus), but this dissection is easily performed in the superficial plane. In addition to using fibrin glue in the undermined areas, the authors drain the neck. They do not use dressings. Recovery was fast, and there were only two instances of hematomas and two instances of subcutaneous cervical fluid

  8. Minimal incision posterior approach levator plication for aponeurotic ptosis

    PubMed Central

    Ng, D S; Chan, E; Ko, S T

    2015-01-01

    Purpose To assess the efficacy and predictability of a minimal incision posterior approach levator plication technique for correction of involutional ptosis. Method Retrospective chart review of patients with involutional aponeurotic ptosis underwent minimal incision posterior approach levator plication technique between August 2013 and June 2014 by a single surgeon. The upper lid was double everted, and the conjunctiva and Muller's muscle layers were incised vertically until the levator aponeurosis could be identified. The incision(s) was similar to performing incision and curettage of chalazion, except that the site was above the tarsal plate and extended towards the fornix. Then insertion of aponeurosis was dissected away from the anterior tarsal surface, and the more superiorly located levator was plicated on it with double arm suture(s). No tissue was excised in this procedure. Surgical success was defined as a postoperative margin reflex distance (MRD)>2 mm and<4.5 mm, interlid height<1 mm and satisfactory contour. Results Forty-four lids of 27 patients were included. Preoperative mean MRD was 0.48 +/− 0.56 mm. Severe ptosis of MRD<1 mm was present in 34/44 patients (77.3%). The postoperative mean MRD was 2.49 +/− 0.53 mm, and mean improvement was 2.02 +/− 0.61 mm, which was statistically significant (P<0.001). The overall success rate was 38/44 (86.4%). Conclusions Minimal incision posterior approach to levator plication was effective for the correction of aponeurotic ptosis with moderate to good levator function. PMID:25613849

  9. Fatal missile injury from the rotating knife of an agricultural mower.

    PubMed

    Roll, P; Klintschar, M

    1998-06-08

    The first case of a lethal injury inflicted by a projectile-wise shot piece of the rotating knife of an agricultural mower (gyro mower) is presented. The knife had travelled approximately 100 m through the air before hitting the victim's body. It transected most organs of the ventral neck including both carotids, the trachea and the esophagus and led to death from exsanguination. The type of the knife which was recovered from the body led to the identification of the mower whose operator had not noticed the accident. Legal action against the user or against the producer of the mower were considered but dismissed as no safety regulations had been violated.

  10. Lateral Erosion Encourages Vertical Incision in a Bimodal Alluvial River

    NASA Astrophysics Data System (ADS)

    Gran, K. B.

    2015-12-01

    Sand can have a strong impact on gravel transport, increasing gravel transport rates by orders of magnitude as sand content increases. Recent experimental work by others indicates that adding sand to an armored bed can even cause armor to break-up and mobilize. These two elements together help explain observations from a bimodal sand and gravel-bedded river, where lateral migration into sand-rich alluvium breaks up the armor layer, encouraging further incision into the bed. Detailed bedload measurements were coupled with surface and subsurface grain size analyses and cross-sectional surveys in a seasonally-incised channel carved into the upper alluvial fan of the Pasig-Potrero River at Mount Pinatubo, Philippines. Pinatubo erupted in 1991, filling valleys draining the flanks of the volcano with primarily sand-sized pyroclastic flow debris. Twenty years after the eruption, sand-rich sediment inputs are strongly seasonal, with most sediment input to the channel during the rainy season. During the dry season, flow condenses from a wide braided planform to a single-thread channel in most of the upper basin, extending several km onto the alluvial fan. This change in planform creates similar unit discharge ranges in summer and winter. Lower sediment loads in the dry season drive vertical incision until the bed is sufficiently armored. Incision proceeds downstream in a wave, with increasing sediment transport rates and decreasing grain size with distance downstream, eventually reaching a gravel-sand transition and return to a braided planform. Incision depths in the gravel-bedded section exceeded 3 meters in parts of a 4 km-long study reach, a depth too great to be explained by predictions from simple winnowing during incision. Instead, lateral migration into sand-rich alluvium provides sufficient fine sediment to break up the armor surface, allowing incision to start anew and increasing the total depth of the seasonally-incised valley. Lateral migration is recorded in a

  11. Relaxation in quantum glasses

    NASA Astrophysics Data System (ADS)

    Ancona Torres, Carlos E.

    The Ising model in transverse field provides the simplest description of a quantum glass. I study two systems that are realizations of the Ising model in transverse field, LiHoxY1-- xF4 and Rb1-- x(NH4)xH2PO 4. In the spin glass LiHoxY1-- xF4, applying a magnetic field Ht transverse to the Ising direction introduces tunneling between the bare Ising eigenstates. In addition, the coupling between the transverse dipolar interaction and the transverse field introduces entanglement or tunable random fields depending on the concentration. By comparing the classical and quantum transitions in LiHo0.198Y0.802F4 and LiHo 0.167Y0.833F4, I characterize the crossover from random field dominated behavior in the 19.8% sample to entanglement dominated behavior in the 16.7% sample. The quantum transition in the 19.8% sample is dominated by the limit on its correlation length caused by the random fields, while the dominant effect in the 16.7% sample is the enhanced tunneling rate introduced by entanglement. The proton glass Rb1--x(NH 4)xH2PO4 relaxes through tunneling of protons in the hydrogen bonds of the crystal, yielding an effective Ising model in transverse field. Since this field cannot be tuned directly, I combine bulk dielectric susceptibility measurements with neutron Compton scattering measurements of the local tunneling potential in two different concentrations, x = 35% and 72%. I find that tunneling drives the fastest relaxation processes at temperatures as high as 20 K and explicitly calculate the tunneling rate from the tunneling potential of the hydrogen bond. Moreover, the structural mechanism for the glassy relaxation allows a real-space picture of the relaxation dynamics to be correlated to the free energy description of aging. I find that the glassy relaxation is driven by the sequential diffusion of defects called Takagi configurations with a classical to quantum crossover in the relaxation at 3 K. I relate the relaxation rate to the quantum action of tunneling

  12. Small incision removal of nylon foil orbital implants.

    PubMed

    Liu, Catherine Y; Vemuri, Swapna; Tao, Jeremiah P

    2015-01-01

    To describe a small incision technique for the removal of a nylon foil orbital wall implant. The authors retrospectively reviewed the charts of 9 patients who underwent a minimally invasive anterior orbitotomy for nylon foil explantation. Indications for removal and surgical technique, including size of orbitotomy incision and extent of orbital dissection, were recorded. Motility, globe position, strabismus pre- and post procedure, and complications were also assessed. Photographs, videos, and postoperative imaging were included, when available. The indications for removal were adjacent sinusitis (4 cases), undesirable implant position (3), orbital abscess (1), and adjacent orbital emphysema (1). The removal technique was associated with no changes in motility, globe position, or strabismus postprocedure. The average incision size was 1.1 cm, and the procedure was rapid, usually seconds once the anterior aspect of the implant was exposed and grasped with a hemostat. The dissection in all cases was to the anterior aspect of the implant without a need for deep orbital manipulation. The authors demonstrate through video that the implant folds to exit through a small incision. No adverse events were noted. Nasal endoscopy and radiography demonstrated a fibrous capsule that maintained orbital structure and support. Thin nylon foil implant can be explanted safely and efficiently through a very small incision. The orbit maintains structure and configuration postexplantation in this series.

  13. Slide crown lengthening procedure using wide surface incisions and cyanoacrylate.

    PubMed

    Szymaitis, Dennis W

    2011-01-01

    This article introduces the slide crown lengthening procedure (SCLP), which incorporates surgical design features to overcome present crown lengthening procedure (CLP) shortcomings. The result is a 75% decrease in required surgery on adjacent teeth and a corresponding 75% reduction in surgical time. Other advantages include a reduction in surgical morbidity, improvement in terminal esthetics, and fewer teeth subject to papillae removal and apically repositioned gingiva. The 20 to 30 degree incision forming the slide is the pivotal feature; it allows effortless flap positioning. This incision angle enables wide surface incisions to adhere flaps together by producing stronger fibrin clots, decreasing tissue retraction angles, and reforming disrupted fibrin clots as incision sides slide while maintaining contact. This enhanced fibrin clot eliminates the need for sutures. The slide produced by the 20 to 30 degree incision functions for crown lengthening on all sites (facial, lingual, or palatal). This versatile surgical design introduces a new healing dimension that adapts to and provides benefits for other dental surgeries, such as gingival grafts, endodontic surgery, implants, and extractions.

  14. Episodic incision of the Colorado River in Glen Canyon, Utah

    USGS Publications Warehouse

    Garvin, C.D.; Hanks, T.C.; Finkel, R.C.; Heimsath, A.M.

    2005-01-01

    Incision rates of the Colorado River are integral to understanding the development of the Colorado Plateau. Here we calculate episodic incision rates of the Colorado River based on absolute ages of two levels of Quaternary deposits adjacent to Glen Canyon, Utah, along the north flank of Navajo Mountain. Minimum surface ages are determined by a combination of cosmogenic radionuclide surface exposure ages, uranium series and soil-development formation times. Bedrock incision rates of the Colorado River between c. 500 ka and c. 250 ka, and c. 250 ka to present are c. 0??4 m ka-1 and c. 0??7 m ka-1, respectively. These rates are more than double the rates reported in the Grand Canyon, suggesting that the Colorado River above Lees Ferry is out of equilibrium with the lower section of the river. We also determine incision rates of two tributaries to the Colorado River. Oak Creek and Bridge Creek flow off Navajo Mountain into Glen Canyon from the southeast. Oak Creek and Bridge Creek both have incision rates of c. 0??6 m ka-1 over the past c. 100 ka at points about 9 km away from the main stem of the Colorado River. Copyright ?? 2005 John Wiley & Sons, Ltd.

  15. Relationship of Incisive Papilla to Maxillary Incisors and Canines.

    PubMed

    Shrestha, Suraksha; Joshi, Sarita Pradhan; Yadav, Santosh Kumar

    2016-04-01

    The study was carried to find a relationship between the postextraction stable landmark, the incisive papilla, and the most labial position of the maxillary central incisor teeth, which occurred in Nepalese population. Casts of the subjects selected by nonprobability random sampling meeting the inclusion criteria were obtained. Each casts were standardized with respect to the occlusal plane and a photographic technique was used to measure the distance from the tangent of the labial surface of the central incisors to the posterior border of the incisive papilla. The measurements were made using Adobe Photoshop and results were analyzed by using appropriate statistical methods. Most appropriate software (SPSS) for the purpose was used to generate all desired values. The data obtained suggested that the distance from the labial surface of maxillary central incisors to the posterior border of the incisive papilla ranged from 9 to 15.9 mm with a mean of 11.59 mm (SD 1.3). Various other results were also found after evaluation of the arch forms in relation to sex and race. Within the limitations of the study, these results suggested that there is a relationship between the maxillary central incisors and the incisive papilla aiding in the anteroposterior positioning of the anterior tooth. The clinical relevance of the study lies in application of the incisive papilla as a starting point in the preliminary location of maxillary incisors and canines during construction of the denture in absence of preextraction records.

  16. Stereotactic radiosurgery using the gamma knife for acoustic neuromas

    SciTech Connect

    Foote, R.L.; Coffey, R.J.; Swanson, J.W.

    1995-07-15

    The purpose of this investigation was to assess the efficacy and toxicity of stereotactic radiosurgery using the gamma knife for acoustic neuromas. Between January 1990 and January 1993, 36 patients with acoustic neuromas were treated with stereotactic radiosurgery using the gamma knife. The median maximum tumor diameter was 21 mm (range: 6-32 mm). Tumor volumes encompasses within the prescribed isodose line varied from 266 to 8,667 mm{sup 3} (median: 3,135 mm{sup 3}). Tumors {<=} 20 mm in maximum diameter received a dose of 20 Gy to the margin, tumors between 21 and 30 mm received 18 Gy, and tumors > 30 mm received 16 Gy. The dose was prescribed to the 50% isodose line in 31 patients and to the 45%, 55%, 60%, 70%, and 80% isodose line in one patient each. Nine tumors (26%) were smaller, and 26 tumors (74%) were unchanged. No tumor had progressed. The 1- and 2-year actuarial incidences of facial neuropathy were 52.2% and 66.5%, respectively. The 1- and 2-year actuarial incidences of trigeminal neuropathy were 33.7% and 58.9%, respectively. The 1- and 2-year actuarial incidence of facial or trigeminal neuropathy (or both) was 60.8% and 81.7%, respectively. Multivariate analysis revealed that the following were associated with the time of onset or worsening of facial weakness or trigeminal neuropathy: (a) patients < age 65 years, (b) dose to the tumor margin, (c) maximum tumor diameter {>=} 21 mm, (d) use of the 18 mm collimator, and (e) use of > five isocenters. The 1- and 2-year actuarial rates of preservation of useful hearing (Gardner-Robertson class I or II) were 100% and 41.7% {plus_minus} 17.3, respectively. Stereotactic radiosurgery using the gamma knife provides short-term control of acoustic neuromas when a dose of 16 to 20 Gy to the tumor margin is used. Preservation of useful hearing can be accomplished in a significant proportion of patients. 30 refs., 5 tabs.

  17. [Effective comparison between improved lateral incision and the traditional L-shaped extension incision in treatment of intra-articular calcaneal fractures].

    PubMed

    Yan, Ying-Qi; Fan, Shun-Wu; Huang, Yue

    2010-11-01

    To compare the clinical outcome between the two different approaches of improved lateral incision and the traditional L-shaped extension incision to treat intra-articular calcaneal fractures. From January 2005 to January 2008, 36 cases of intra-articular calcaneal fractures were treated by improved lateral incision or the traditional L-shaped extension incision. In improved lateral incision group, there were 19 cases including 12 males and 7 females with an average age of (38.1 +/- 9.1) years; According to Sanders classification: 8 cases were type II, 9 were type III, 2 were type IV; The time from injury to the operation was (10.5 +/- 1.7) days. In the traditional L-shaped extension incision group,there were 17 cases including 11 males and 6 females with an average age of (38.4 +/- 7.3) years; according to Sanders classification of fractures: 7 cases were type II, 9 were type III, 1 was type IV; The time from injury to the operation was (10.6 +/- 1.8) days. Observing and comparing some items of the two groups including (1) operation time, blood loss, incision length, number of graft cases, (2) VAS pain scores after the first day, (3) wound healing, (4) Maryland foot scoring, (5) postoperative imaging results were comparative analyzed. Two groups of patients were followed up from 10 to 15 months with an average of 11 months. The operative time and number of graft cases were compared between two groups with no statistically significant differences. The blood loss were (94.0 +/- 9.5) ml in improved lateral incision group and (109.9 +/- 13.7) ml in L-shaped extension incision group, incision length were (6.8 +/- 1.1) cm in improved lateral incision group and (15.7 +/- 2.2) cm in L-shaped extension incision group with significant differences. Postoperative VAS pain score at the first day were (1.95 +/- 0.71) points in improved lateral incision group and (3.65 +/- 1.00) points in L-shaped incision group with significant difference. In improved lateral incision group

  18. The problem of insufficient incisal display: a case presentation.

    PubMed

    Castillo, Rodrigo

    2010-01-01

    Enhancement of facial beauty is one of the primary elective goals of patients seeking dental care. Frequently, improvements in natural beauty can be expected to follow restoration of ideal relationships between the denture and the facial soft tissues. A very important feature in a youthful appearance is the incisal tooth display; the amount of maxillary incisal exposure gradually decreases with age, accompanied by a gradual increase in mandibular incisal exposure. However, this problem could be present in young people where the effects of age should not be apparent yet. There are some other factors that could accelerate this process. The present case illustrates the improvement and rejuvenation of an unesthetic young smile through restorative treatment.

  19. Force modeling for incision surgery into tissue with haptic application

    NASA Astrophysics Data System (ADS)

    Kim, Pyunghwa; Kim, Soomin; Choi, Seung-Hyun; Oh, Jong-Seok; Choi, Seung-Bok

    2015-04-01

    This paper presents a novel force modeling for an incision surgery into tissue and its haptic application for a surgeon. During the robot-assisted incision surgery, it is highly urgent to develop the haptic system for realizing sense of touch in the surgical area because surgeons cannot sense sensations. To achieve this goal, the force modeling related to reaction force of biological tissue is proposed in the perspective on energy. The force model describes reaction force focused on the elastic feature of tissue during the incision surgery. Furthermore, the force is realized using calculated information from the model by haptic device using magnetorheological fluid (MRF). The performance of realized force that is controlled by PID controller with open loop control is evaluated.

  20. Single Incision Laparoscopic Colectomy: Technical Aspects, Feasibility, and Expected Benefits

    PubMed Central

    Leblanc, F.; Champagne, B. J.; Augestad, K. M.; Stein, S. L.; Marderstein, E.; Reynolds, H. L.; Delaney, C. P.

    2010-01-01

    Background. This paper studied technical aspects and feasibility of single incision laparoscopic colectomy (SILC). Methods. Bibliographic search was carried out up to October 2009 including original articles, case reports, and technical notes. Assessed criteria were techniques, operative time, scar length, conversion, complications, and hospitalization duration. Results. The review analyzed seventeen SILCs by seven surgical teams. A single port system was used by four teams. No team used the same laparoscope. Two teams used two laparoscopes. All teams used curved instruments. SILC time was 116 ± 34 minutes. Final scar was longer than port incision (31 ± 7 versus 24 ± 8 mm; P = .036). No conversion was reported. The only complication was a bacteremia. Hospitalization was 5 ± 2 days. Conclusion. SILC is feasible. A single incision around the umbilical scar represents cosmetic progress. Comparative studies are needed to assess potential abdominal wall and recovery benefits to justify the increased cost of SILC. PMID:20585367

  1. Giant Nasolabial Cyst Treated Using Neumann Incision: Case Report

    PubMed Central

    Ordones, Alexandre Beraldo; Neri, Larissa; Oliveira, Ingrid Helena Lopes; Tepedino, Miguel Soares; Pinna, Fábio de Rezende; Voegels, Richard Louis

    2013-01-01

    Introduction A nasolabial cyst is an ectodermal development cyst. It presents as a fullness of canine fossa, nasal ala, or vestibule of the nose. It is rare and usually small. Treatment consists of complete surgical excision or transnasal endoscopic marsupialization. Objective To describe a giant nasolabial cyst case treated using Neumann incision. Case Report A 37-year-old man was referred to the otolaryngology department with nasal obstruction and nasal deformity. Computed tomography showed a nasal cystic lesion 4 × 4.5 × 5 cm wide. Surgical excision using Neumann incision was performed. Discussion Neumann incision provides wide access to the nasal cavity and may be useful in nasolabial cyst treatment. PMID:25992051

  2. Vascular alterations in the rabbit patellar tendon after surgical incision

    PubMed Central

    DOSCHAK, M. R.; MATYAS, J. R.; HART, D. A.; BRAY, R. C.

    2001-01-01

    Open incision of the patellar tendon (PT) is thought to promote acute vascular responses which ultimately result in an enhanced degree of tendon repair. Such a clinical procedure is commonly applied to patients with refractory tendinitis. The objective of this study was to quantify the vascular adaptations (both anatomical and physiological) to longitudinal incision of the PT, and the resultant effects on tendon organisation. Fifty-four New Zealand White rabbits were separated into 3 experimental groups and 2 control groups. Experimental groups underwent surgical incision of the right PT, and were assessed 3 d, 10 d and 42 d following injury; normal unoperated controls were evaluated at time zero, and sham-operated controls were evaluated at 3 d to control for the effects of incising the overlying skin. Quantitative measures of PT blood supply (blood flow, microvascular volume) and geometric properties of PT substance were obtained for each PT. Histomorphology was assessed to evaluate vascular remodelling and matrix organisation in the healing PT. Longitudinal open incision surgery of the PT led to rapid increases in both blood flow and vascular volume. The incision of overlying tissues alone (sham-operated) contributed to this measurable increase, and accounted for 36% and 42% of the elevated blood flow and vascular volume respectively at the 3 d interval. In the incised PT, blood flow significantly increased by 3 d compared with both time zero and sham-operated controls, and remained significantly elevated at the 10 d interval. Similarly, vascular volume of the incised PT increased at 3 d compared both with time zero and sham-operated controls. At the 10 d interval, the increase in vascular volume was greatest in the central PT substance. By 42 d both blood flow and vascular volume of the incised tendon had diminished, with only blood flow remaining significantly different from controls. In the contralateral limb, a significant neurogenically mediated

  3. Influence on grip of knife handle surface characteristics and wearing protective gloves.

    PubMed

    Claudon, Laurent

    2006-11-01

    Ten subjects were asked to apply maximum torques on knife handles with either their bare hand or their hand wearing a Kevlar fibre protective glove. Four knife handles (2 roughnesses, 2 hardnesses) were tested. Surface electromyograms of 6 upper limb and shoulder muscles were recorded and subject opinions on both knife handle hardness and friction in the hand were also assessed. The results revealed the significant influence of wearing gloves (p<0.0001), knife type (p<0.0005) and handle hardness (p<0.005) on the applied torque. Wearing Kevlar fibre gloves greatly increased the torque independently of the other two parameters. Under the bare hand condition, a 90 degrees ShA slightly rough handle provided the greatest torque. Subject opinion agreed with the observed effects on recorded torque values except for the hardness factor, for which a preference for the 70 degrees ShA value over the 90 degrees ShA value emerged.

  4. Optimal Shape of a Gamma-ray Collimator: single vs double knife edge

    NASA Astrophysics Data System (ADS)

    Metz, Albert; Hogenbirk, Alfred

    2017-09-01

    Gamma-ray collimators in nuclear waste scanners are used for selecting a narrow vertical segment in activity measurements of waste vessels. The system that is used by NRG uses tapered slit collimators of both the single and double knife edge type. The properties of these collimators were investigated by means of Monte Carlo simulations. We found that single knife edge collimators are highly preferable for a conservative estimate of the activity of the waste vessels. These collimators show much less dependence on the angle of incidence of the radiation than double knife edge collimators. This conclusion also applies to cylindrical collimators of the single knife edge type, that are generally used in medical imaging spectroscopy.

  5. Non-uniform sampling knife-edge method for camera modulation transfer function measurement

    NASA Astrophysics Data System (ADS)

    Duan, Yaxuan; Xue, Xun; Chen, Yongquan; Tian, Liude; Zhao, Jianke; Gao, Limin

    2016-11-01

    Traditional slanted knife-edge method experiences large errors in the camera modulation transfer function (MTF) due to tilt angle error in the knife-edge resulting in non-uniform sampling of the edge spread function. In order to resolve this problem, a non -uniform sampling knife-edge method for camera MTF measurement is proposed. By applying a simple direct calculation of the Fourier transform of the derivative for the non-uniform sampling data, the camera super-sampled MTF results are obtained. Theoretical simulations for images with and without noise under different tilt angle errors are run using the proposed method. It is demonstrated that the MTF results are insensitive to tilt angle errors. To verify the accuracy of the proposed method, an experimental setup for camera MTF measurement is established. Measurement results show that the proposed method is superior to traditional methods, and improves the universality of the slanted knife-edge method for camera MTF measurement.

  6. Liminal Masculinity in Richard Selzer's Knife Song Korea.

    PubMed

    Sun, Jiena

    2014-03-01

    The doctor in a foreign country is a recurring theme in physician writer Richard Selzer's stories. In his 2009 novel, Knife Song Korea, Selzer returns to this theme, examining it in depth through the lens of gender. Selzer features the American military surgeon Sloane's multiple border-crossings, namely, from America to Korea, from health to patienthood, and from sex-exploitation to love. Crossing those visible or invisible borders in the gender and race conscious contexts of medical profession and military in wartime Korea, Sloane finds himself liminally located among various masculine stereotypes. The mixed-race situation in the novel further pushes Sloane to realize the unbearability of the baggage of American manhood as represented in his profession. Selzer's punishment of Sloane's border-crossings seems to suggest that physicians, together with patients, are equally likely to be victimized by the macho norms in medicine.

  7. Gamma knife radiosurgery for the treatment of brain metastases.

    PubMed

    Sansur, C A; Chin, L S; Ames, J W; Banegura, A T; Aggarwal, S; Ballesteros, M; Amin, P; Simard, J M; Eisenberg, H

    2000-01-01

    One hundred and ninety-three patients with brain metastases from various primary sites received Gamma Knife radiosurgery (GKR) from July 1992 to August 1997 and were reviewed to evaluate their clinical outcome. Survival follow-up was available on 173 patients. Whole-brain radiation therapy was also administered to 148 of these patients. The median survival was 13.1 months from initial detection of brain metastases, and 7.5 months from GKR. Univariate and multivariate analyses were performed to determine prognostic factors that influenced survival following GKR. Enhanced survival is observed in patients with radiosensitive tumor types, supratentorial tumor, history of brain tumor resection, controlled primary site, and absent extracranial metastases. Local lesion control was obtained in 82% of the patients according to their last follow-up MRI scan. GKR is an effective means of treating patients with brain metastases.

  8. Modeling of laser knife-edge and pinhole experiments

    NASA Astrophysics Data System (ADS)

    Boley, Charles D.; Estabrook, Kent G.; Auerbach, Jerome M.; Feit, Michael D.; Rubenchik, Alexander M.

    1999-07-01

    We describe simulations of experiments invovling laser illumination of a metallic knife edge in the Optical Sciences Laboratory (OSL) at LLNL, and pinhole closure in the Beamlet experiment at LLNL. The plasma evolution is modeled via LASNEX. In OSL, the calculated phases of a probe beam are found to exhibit the same behavior as in experiment but to be consistently larger. The motion of a given phase contour tends to decelerate at high intensities. At fixed intensity, the speed decreases with atomic mass. We then calculate the plasma associated with 4-leaf pinholes on the Beamlet transport spatial filter. We employ a new propagation code to follow a realistic input beam through the entire spatial filter, including the plasmas. The detailed behavior of the output wavefronts is obtained. We show how closure depends on the orientation and material of the pinholes blades. As observed in experiment, a diamond orientation is preferable to a square orientation, and tantalum performs better than stainless steel.

  9. A modular Geant4 model of Leksell Gamma Knife Perfexion™

    NASA Astrophysics Data System (ADS)

    Pipek, J.; Novotný, J.; Novotný, J., Jr.; Kozubíková, P.

    2014-12-01

    This work presents a Monte Carlo model of Leksell Gamma Knife Perfexion as well as the main parameters of the dose distribution in the standard phantom obtained using this model. The model is developed in the Geant4 simulation toolkit in a modular way which enables its reuse in other Perfexion studies. Large phase space files were created, containing particles that are entering the inner machine cavity after being transported through the collimation system. All 14 output factors of the machine and effective output factors for both the 4 mm (0.830 ± 0.009) and 8 mm (0.921 ± 0.004) collimators were calculated. Dose profiles along the main axes are also included for each collimator size. All results are compared to the values obtained from the treatment planning system, from experiments, and from other Monte Carlo models.

  10. Single-incision laparoscopy surgery: a systematic review

    PubMed Central

    far, Sasan Saeed; Miraj, Sepide

    2016-01-01

    Background Laparoscopic surgery is a modern surgical technique in which operations are performed far from their location through small incisions elsewhere in the body. Objective This systematic review is aimed to overview single-incision laparoscopy surgery. Methods This systematic review was carried out by searching studies in PubMed, Medline, Web of Science, and IranMedex databases. The initial search strategy identified about 87 references. In this study, 54 studies were accepted for further screening and met all our inclusion criteria [in English, full text, therapeutic effects of single-incision laparoscopy surgery and dated mainly from the year 1990 to 2016]. The search terms were “single-incision,” “surgery,” and “laparoscopy.” Results Single-incision laparoscopy surgery is widely used for surgical operations in cholecystectomy, sleeve gastrectomy, cholecystoduodenostomy, hepatobiliary disease, colon cancer, obesity, appendectomy, liver surgery, rectosigmoid cancer, vaginal hysterectomy, vaginoplasty, colorectal lung metastases, pyloroplasty, endoscopic surgery, hernia repair, nephrectomy, rectal cancer, colectomy and uterus-preserving repair, bile duct exploration, ileo-ileal resection, lymphadenectomy, incarcerated inguinal hernia, anastomosis, congenital anomaly, colectomy for cancer. Conclusion Based on the findings, single-incision laparoscopy surgery is a scarless surgery with minimal access. Although it possesses lots of benefits, including less incisional pain and scars, cosmesis, and the ability to convert to standard multiport laparoscopic surgery, it has some disadvantages, for example, less freedom of movement, fewer number of ports that can be used, and the proximity of the instruments to each other during the operation. PMID:27957308

  11. Hypopituitarism after gamma knife radiosurgery for pituitary adenoma.

    PubMed

    Zibar Tomšić, Karin; Dušek, Tina; Kraljević, Ivana; Heinrich, Zdravko; Solak, Mirsala; Vučinović, Ana; Ozretić, David; Mihailović Marasanov, Sergej; Hršak, Hrvoje; Kaštelan, Darko

    2017-05-24

    The aim of the study was to investigate the incidence of and risk factors for hypopituitarism after gamma knife radiosurgery (GKRS) for pituitary adenoma. We conducted a retrospective analysis of the pituitary function of 90 patients who underwent GKRS for pituitary adenoma at the University Hospital Centre Zagreb between 2003 and 2014. Twenty seven of them met the inclusion criteria and the others were excluded from the study due to pituitary insufficiency which was present before GKRS. Eighteen patients had non-functioning and 9 patients had secretory adenomas. Median patients' age was 56 years (24-82). GKRS was performed using the Leksell gamma knife Model C. The median prescription radiation dose was 20 Gy (15-25) and the median tumor volume size was 3.4 cm(3) (0.06-16.81). New onset hypopituitarism was defined as a new deficit of one of the three hormonal axes (corticotroph, thyreotroph, or gonadotroph) ≥3 months following GKRS. SPSS was used for statistical analysis, with the significance level at P<0.05. During the median follow-up period of 72 months (range 6-144), 30% of patients developed new hypopituitarism after GKRS. This corresponds to incidence of one new case of hypopituitarism per 15 patient-years. Age, gender, tumor function, tumor volume, suprasellar extension, prescription dose of radiation, as well as dose-volume to the pituitary gland, stalk and hypothalamus were not predictive factors for the development of hypopituitarism. In our cohort of patients with pituitary tumors who underwent GKRS, 30% developed new hypopituitarism during the follow-up period.

  12. [Clitoromegaly--treatment with the harmonic knife (case description)].

    PubMed

    Daniłoś, Jarosław; Morawska, Dorota; Stachowicz, Norbert; Kotarski, Jan

    2013-01-01

    Clitoromegaly, state when clitoris is non-physiologically large, most frequently occurs among patients with endocrine disorders (adrenal-genital syndrome, hormonally active tumors producing androgens, the use of anabolic steroids) or genetic. Less often the clitoromegaly is idiopathic of unknown etiology. There are no fixed standards for the size of organ, but it is assumed that not being in erect clitoris due to sexual arousal has a diameter of no more than 1/2 cm. To assess the size and shape of the clitoris can be used five Prader scale. However, it is most commonly used to assess the genitals of intersex. To the Clinic of Gynecology Oncology and Gynecology reported a 33 year old female patient because of escalating discomfort in sexual life. Patient associated her discomfort with her overly enlarged and painful clitoris preventing its proper coexistence. Gynecological survey found the correct size uterus and appendages. Vestibule of the vagina and the vagina of normal length and width. Larger and smaller labia developed properly. Clitoris increased to approximately 4x2 cm, not swollen, moving, with a uniform consistency. Except clitoromegaly in initial examination no abnormalities were found. Prior to surgery the patient has identified karyotype (46 XX) and has made designation of the levels of sex hormones and sonographic examination. In conducting these studies there was no answer found for the reason of clitoromegaly, there was the idiopathic overgrowth stated. Because of the pain during cohabitation associated with clitoromegaly, the patient was classified for reducing operation of this organ. For fear of the possibility of organ dysfunction, excessive bleeding and the appearance of postoperative adhesions abandoned classical surgical technique. It was decided to use in this operation, the harmonic knife. The use of harmonic knife allows avoiding introperative bleeding and precise, a partial reduction of the clitoris to the considered correct size without

  13. Facilitated thyrotropin release after retrochiasmatic hypothalamic knife cuts.

    PubMed

    Phelps, C P; Colombo, J A

    1981-03-01

    Diencephalic structures that influence plasma thyrotropin (TSH) in male rats under pentobarbital anesthesia (35 mg/kg, IP) were studied by combining medial preoptic area-suprachiasmatic nucleus (MPOA-Sch) bilateral electrical stimulation (monophasic pulses, 200 microA at 50 Hz, 30 min) with progressive midline lesions produced by a retractable Halász knife. Plasma TSH was measured by radioimmunoassay just before (0 time) and at 30, 60 and 90 min after the beginning of stimulation. Rats that had received only sham surgical procedures 90 days prior to stimulation were characterized by a more than 2-3 fold elevation in basal (0 time) plasma TSH levels when compared to those found in intact control rats and expected elevations in plasma TSH at 30 min after stimulation were eliminated. After a small frontal cut (1.3 FC), 0 time plasma TSH levels increased more tha 4-fold above those of controls in association with a facilitation of stimulated release of TSH. When the knife blade radius was 1.5 mm (1.5 FC) the facilitation of TSH release after stimulation occurred again; however, 0 time plasma TSH concentrations in 1.5 FC rats were not different from control levels. These effects of midline cortical, thalamic and hypothalamic damage on TSH release required the passage of more than 12 days after brain surgery. Collectively, these findings suggest potential neural elements that are inhibitory for 'basal' and 'phasic' TSH release which are in close proximity to a separate excitatory neural system and which can be activated by MPOA-Sch stimulation.

  14. Gamma knife radiosurgery of recurrent central neurocytomas: a preliminary report

    PubMed Central

    Bertalanffy, A; Roessler, K; Dietrich, W; Aichholzer, M; Prayer, D; Ertl, A; Kitz, K

    2001-01-01

    OBJECTIVES—A series of three recurrent central neurocytomas treated by gamma knife radiosurgery (GKRS), which were initially totally resected, are described. Up to now, no reports exist on this treatment modality for this rare tumour entity.
METHODS—Three male patients, aged between 20 and 25 years, presented with large intraventricular tumours. Total tumour removal was achieved by a single surgical procedure (one patient) or two operations (two patients). Neuropathological investigation showed a central neurocytoma, immunohistochemically all three tumours expressed a neuronal antigenetic profile typical for neurocytomas, and the MIB-1 proliferation index ranged from 2.4% to 8.7%. Each patient experienced a tumour recurrence after 5 to 6 years. The recurrence was multifocal in two and a singular tumour mass in one patient. Gamma knife radiosurgery was performed. The tumours were enclosed within the 30% to 60% isodoseline, and delivered a tumour marginal dose of 9.6 to 16 Gy. During the follow up period, the patients were tested clinically and the volume of the tumours was measured on MRI.
RESULTS—Within follow up periods of 1 to 5 years, control MRI showed a significant decrease of the tumour mass in all cases. None of the patients developed new neurological symptoms after GKRS. Two patients returned to work in their previous employment, whereas one patient remained permanently disabled due to a pre-existing visual impairment and abducens palsy.
CONCLUSION—GKRS proved to be a useful tool in the treatment of recurrent central neurocytomas. Tumour control and even tumour shrinkage can be achieved with a single procedure and a low risk of morbidity.

 PMID:11254772

  15. In-line digital holography with double knife edge

    NASA Astrophysics Data System (ADS)

    Ramirez, Claudio; Iemmi, Claudio; Campos, Juan

    2015-06-01

    We study and test a new technique for in-line digital holography which avoids the formation of the conjugate images. Inline digital holography is based in a common path configuration. In this case, the hologram is produced by the interference between the reference wave front and the diffracted wave front by an almost transparent object. Twin images are obtained with obscured rings that difficult the determination of the best focusing plane. To avoid the conjugated image, the information of the magnitude and phase of the wave front are needed. In a recent work a new in-line digital holography technique was proposed. In this method the object is illuminated with a collimated wave front. A plane, close to the particles distribution is imaged onto a CCD by means of a convergent lens and at the same time, a knife edge is placed in the focal plane of the lens in order to block half of spatial frequency spectrum. In this way, by means of a numerical processing performed on the Fourier plane, it is possible to eliminate one of the components (real or conjugate) of the reconstructed images nevertheless it is observed a tiny deformation of the resulting hologram image. To compensate this effect, we propose a new configuration in which we implement the knife edge technique on both parts of the spectrum at the same time. Finally in the computer, we process the holograms to build one complete without deformation. This hologram is used to recover the wave front at different planes without the influence of the conjugate image.

  16. Quality of life: Gamma Knife surgery and whole brain radiation therapy.

    PubMed

    Nesbitt, Janice

    2007-01-01

    Cerebral metastasis of cancers originating outside the brain has traditionally been treated with whole brain radiation therapy (WBRT). Gamma Knife Radiosurgery (GKS) provides safe and effective alternative treatment that is less invasive and has fewer side effects. Both WBRT and GKS are reviewed and discussed in terms of quality of life and health outcomes. The case studies of two individuals who underwent Gamma Knife surgery are presented.

  17. Gamma knife surgery-induced ependymoma after the treatment of meningioma - a case report.

    PubMed

    Wang, Ke; Pan, Li; Che, Xiaoming; Lou, Meiqing

    2012-01-01

    Gamma knife surgery is widely used for a number of neurological disorders. However, little is known about its long-term complications such as carcinogenic risks. Here, we present a case of a radiosurgery-induced ependymoma by gamma knife surgery for the treatment of a spinal meningioma in a 7-year-old patient. In light of reviewing the previous reports, we advocate high caution in making young patients receive this treatment.

  18. A novel technique of anesthesia induction in supine position with impaled knife in the back

    PubMed Central

    Kumar, Ajay; Saha, Kamales Kumar; Jagiasi, Bharat; Saha, Kakalee K

    2015-01-01

    Current technique of airway management for impaled knife in the back includes putting the patient in lateral position and intubation. We present here a novel technique of anesthesia induction (intubation and central line insertion) in a patient with impaled knife in the back which is simple and easily reproducible. This technique can be used for single lung ventilation using double lumen tube or bronchial blocker also if desired. PMID:25849698

  19. Single Incision Laparoscopic Cholecystectomy in situs Inversus Totalis

    PubMed Central

    Bozkurt, Suleyman; Coskun, Halil; Atak, Tuba; Kadioglu, Huseyin

    2012-01-01

    Situs inversus totalis (SIT) is a rare genetic anomaly characterized by arrangement of the abdominal and thoracic organs in a perfect mirror image reversal of the normal positioning. Transposition of the organs causes difficulty in diagnosis and treatment of the diseases related to abdomen and thorax. Single incision laparoscopic surgery (SILS) is a new technique and it is increasingly used with better cosmetic results. In this paper, a single incision laparoscopic cholecystectomy (SILC) performed in a patient with SIT is presented. SILC can be performed safely in the patients with SIT with better cosmetic results. PMID:23741594

  20. Single Incision Laparoscopic Cholecystectomy in situs Inversus Totalis.

    PubMed

    Bozkurt, Suleyman; Coskun, Halil; Atak, Tuba; Kadioglu, Huseyin

    2012-07-01

    Situs inversus totalis (SIT) is a rare genetic anomaly characterized by arrangement of the abdominal and thoracic organs in a perfect mirror image reversal of the normal positioning. Transposition of the organs causes difficulty in diagnosis and treatment of the diseases related to abdomen and thorax. Single incision laparoscopic surgery (SILS) is a new technique and it is increasingly used with better cosmetic results. In this paper, a single incision laparoscopic cholecystectomy (SILC) performed in a patient with SIT is presented. SILC can be performed safely in the patients with SIT with better cosmetic results.

  1. Modified temporal incision for facial rhytidectomy: an 18-year experience.

    PubMed

    Guyuron, Bahman; Watkins, Frederick; Totonchi, Ali

    2005-02-01

    An 18-year experience with the senior author's temporal incision is expounded. First, the existing sideburn is outlined with a marking pen. A sideburn is designed approximately 2 cm wide and 2 cm long, regardless of the extent of the existing sideburn providing the minimum sideburn. The posterocaudal portions of the newly designed sideburn will correspond to that of the existing dense portion of the sideburn. After dissection and removal of excess skin, the entire vertical portion of the scar will remain within the hair-bearing skin, eliminating the potential for visibility unless preoperatively the sideburn is less that 2 cm wide. There are several advantages to this approach. First, the configuration of the sideburn remains essentially unaltered. Second, the length of distribution for the redundant redraped facial skin is increased in comparison with most other incisions, thus avoiding a dog-ear regardless of the extent of the excess facial skin. Rhytidectomy is more effective because the distance from the incision to the nasolabial crease and the oral commissure is reduced, thereby effectively transmitting the traction forces to these sites compared with the conventional temporal incision that is placed above the ear. In addition, exposure of the surgical field is significantly enhanced by the added ability to rotate the skin flap medially. The potential disadvantage is that the operative time is increased to accommodate meticulous repair of the temporal incision. A slight modification of this incision has been implemented over the past 18 years, placing the anterior vertical incision farther posterior compared with the original report. The horizontal and posterior vertical portions of the incision are positioned at the hairline, resulting in an inconspicuous scar. None of the 125 patients in this latter group required a scar revision compared with 37 (4.28 percent) of 865 patients before this modification. This technique effectively achieves the goal of facial

  2. Columellar Incision Scars in Asian Patients Undergoing Open Rhinoplasty.

    PubMed

    Kim, Ho Chan; Jang, Yong Ju

    2016-05-01

    An open approach has been adopted for rhinoplasty because of its wide and undistorted exposure. The formation of a columellar incision scar is the main drawback of this approach. To evaluate the incidence and evolution of and risk factors for columellar incision scars in an Asian population. A retrospective case series of 529 patients who underwent open rhinoplasty was performed in a tertiary care referral center in South Korea from January 1, 2011, to May 31, 2014. Problematic transcolumellar incision scars were categorized into wide and depressed, notching, and hyperpigmented wound types. Follow-up was complete on January 28, 2015, and data were assessed from July 1, 2014, to May 29, 2015. The incidence of each problematic scar and the time course of erythema evolution were evaluated. Factors affecting the formation of a problematic scar were also evaluated. Of 529 patients (176 female and 353 male patients; mean age, 31 [range, 5-70] years), 234 patients with at least 6 months of follow-up underwent evaluation for a problematic scar. Fourteen of the 234 patients (6.0%) had problematic incision scarring (wide and depressed wound, 4 [1.7%]; notching wound, 3 [1.3%]; hyperpigmentation, 4 [1.7%]; marginal incision hypertrophic scar, 2 [0.8%]; and columellar skin necrosis, 1 [0.4%]). Of the 243 patients with regular follow-up who underwent evaluation for erythema evolution, erythematous wounds were found in almost all in the immediate postoperative period and had normalized by a mean (SD) of 66.7 (37.4) postoperative days. Use of costal cartilage as tip graft material was associated with a problematic incision scar (2 of 25 patients [8.0%] vs 6 of 180 patients with other graft material [3.3%]; P = .02). In this cohort of Asian patients, the incisions used for an open rhinoplasty approach had some problems. However, the low incidence of problematic scars indicates that open rhinoplasty should not be discouraged because of the incision scar. 4.

  3. Long-Term Results of Gamma Knife Radiosurgery for Intracranial Meningioma.

    PubMed

    Jang, Chang Ki; Jung, Hyun Ho; Chang, Jong Hee; Chang, Jin Woo; Park, Yong Gou; Chang, Won Seok

    2015-10-01

    The predominant treatment modality for meningioma is surgical resection. However, gamma knife radiosurgery is also an important treatment modality for meningioma that is small or cannot be completely removed because of its location. In this study, we evaluated the effectiveness and long-term results of radiosurgical treatment for meningioma in our institution. We studied 628 patients (130 men and 498 women) who underwent gamma knife radiosurgery for intracranial meningioma, which is radiologically diagnosed, from Jan 2008 to Nov 2012. We included patients with single lesion meningioma, and followed up after 6 months with imaging, and then at 24 months with a clinical examination. Patients with high-grade meningioma or multiple meningiomas were excluded. We analyzed each of the factors associated with progression free survival. The median patient's age was 56.8 years. Maximal dosage was 27.8 Gy and marginal dosage was 13.9 Gy. The overall tumor control rate was 95%. Twenty-eight patients (4.4%) showed evidence of tumor recurrence. Ninety-eight patients (15%) developed peritumoral edema (PTE) after gamma-knife surgery; two of them (2%) underwent surgical resections due to PTE. Nine patients had craniotomy and tumor removal after gamma knife surgery. Gamma knife surgery for intracranial meningioma has proven to be a safe and effective treatment tool with successful long-term outcomes. Gamma knife radiosurgery can be especially effective in cases of remnant meningioma after surgical resection or where PTE is not present.

  4. Long-Term Results of Gamma Knife Radiosurgery for Intracranial Meningioma

    PubMed Central

    Jang, Chang Ki; Jung, Hyun Ho; Chang, Jong Hee; Chang, Jin Woo; Park, Yong Gou

    2015-01-01

    Background The predominant treatment modality for meningioma is surgical resection. However, gamma knife radiosurgery is also an important treatment modality for meningioma that is small or cannot be completely removed because of its location. In this study, we evaluated the effectiveness and long-term results of radiosurgical treatment for meningioma in our institution. Methods We studied 628 patients (130 men and 498 women) who underwent gamma knife radiosurgery for intracranial meningioma, which is radiologically diagnosed, from Jan 2008 to Nov 2012. We included patients with single lesion meningioma, and followed up after 6 months with imaging, and then at 24 months with a clinical examination. Patients with high-grade meningioma or multiple meningiomas were excluded. We analyzed each of the factors associated with progression free survival. The median patient's age was 56.8 years. Maximal dosage was 27.8 Gy and marginal dosage was 13.9 Gy. Results The overall tumor control rate was 95%. Twenty-eight patients (4.4%) showed evidence of tumor recurrence. Ninety-eight patients (15%) developed peritumoral edema (PTE) after gamma-knife surgery; two of them (2%) underwent surgical resections due to PTE. Nine patients had craniotomy and tumor removal after gamma knife surgery. Conclusion Gamma knife surgery for intracranial meningioma has proven to be a safe and effective treatment tool with successful long-term outcomes. Gamma knife radiosurgery can be especially effective in cases of remnant meningioma after surgical resection or where PTE is not present. PMID:26605265

  5. Obesity-inducing hypothalamic knife cuts: effects on lipolysis and blood insulin levels.

    PubMed

    Bray, G A; Sclafani, A; Novin, D

    1982-09-01

    The effect of two experimental manipulations designed to mobilize lipids from adipose tissue have been investigated in rats with parasagittal knife cuts in the ventromedial hypothalamus (VMH). Those animals which displayed hyperphagia during the initial 5 days VMH knife cuts were then restricted in food intake to reduce body weights to levels comparable to that of the sham-operated controls. Two weeks following the knife-cut lesions, or sham operations, animals in the first experiment were exposed to the cold for 60 min, and those in the second experiment were injected with 2-deoxy-D-glucose (2-DG). The injections of 2-DG increased the level of glycerol in the control animals but not in the animals with VMH knife cuts. Both groups showed a rise in glucose. Plasma insulin and triglycerides were the same in both groups. Exposure to the cold increased the level of glycerol in both groups. The insulin levels were lower in the corresponding groups with knife cuts. These studies show that VMH knife cuts do not produce hyperinsulinemia in pair-gained rats.

  6. Effects of oral and parenteral quinine on rats with ventromedial hypothalamic knife-cut obesity.

    PubMed

    Oku, J; Bray, G A; Fisler, J S

    1984-06-01

    The addition of quinine to the food reversed the obesity in rats with hypothalamic hyperphagia induced by knife cuts. Similarly, the injection of quinine into rats with hypothalamic knife cuts reduced food intake and body weight but the effects were smaller than those observed when quinine was added to the diet. Urinary quinine excretion was similar by the oral and parenteral routes. The food intake of the knife-cut animals receiving quinine gradually fell to the same level as in the sham-operated animals receiving quinine by either route. The weights of retroperitoneal fat pads were related to the weights of the animals and were reduced in the quinine-treated groups. Plasma insulin concentrations were significantly higher in the knife-cut animals and were reduced toward control levels by quinine treatment. Gluconeogenesis, measured by incorporation of radioactivity from labeled bicarbonate into glucose, was unaffected by treatment with quinine or by knife cuts. Lipogenesis from tritiated water in vivo was not different between treatment groups in the liver or retroperitoneal fat pads. However, in vivo lipogenesis was reduced in knife-cut rats fed ad libitum compared with quinine-treated rats. The response of lipogenesis to insulin in vitro was also not different between treatment groups. These data suggest that a major part of the reduction in food intake in hyperphagic rats eating a quinine-adulterated diet is due to postingestional events.

  7. Ventromedial hypothalamic knife-cut lesions in rats resistant to dietary obesity.

    PubMed

    Oku, J; Bray, G A; Fisler, J S; Schemmel, R

    1984-06-01

    The effects of ventromedial hypothalamic (VMH) knife-cut lesions on food intake and body weight of S 5B/Pl rats, which are normally resistant to obesity when eating a high-fat diet, were examined in two experiments. In the first experiment body weight increased only slightly after VMH knife-cut lesions when animals were fed pelleted laboratory chow or a 10% corn oil diet. When eating the 30% corn oil diet, however, body weight increased in the VMH knife-cut rats. In the second experiment VMH knife-cut lesions produced a small weight gain in rats fed the 10% fat diet; this manipulation also increased food intake and disrupted the normal diurnal feeding pattern. Changes in the weight of the liver, interscapular brown adipose tissue, and white adipose tissue paralleled the changes in body weight. Plasma insulin increased in the rats eating the 30% corn oil diet ad libitum but not in the VMH-lesioned animals pair fed to the sham-operated rats. Incorporation of 3H from 3H2O into lipid was significantly increased in white fat of animals with VMH knife cuts. Similar results were obtained from incubation of adipose tissue in vitro with insulin and radioactively labeled glucose. These studies show that hypothalamic knife-cut lesions can remove the resistance of the S 5B/Pl rats to obesity when they are fed a high-fat diet.

  8. Peripheral dose measurement for CyberKnife radiosurgery with upgraded linac shielding

    SciTech Connect

    Chuang, Cynthia F.; Larson, David A.; Zytkovicz, Andrea; Smith, Vernon; Petti, Paula L.

    2008-04-15

    The authors investigated the peripheral dose reduction for CyberKnife radiosurgery treatments after the installation of a linac shielding upgrade. As in a previous investigation, the authors considered two treatment plans, one for a hypothetical target in the brain and another for a target in the thorax, delivered to an anthropomorphic phantom. The results of the prior investigation showed that the CyberKnife delivered significantly higher peripheral doses than comparable model C Gamma Knife or IMRT treatments. Current measurements, after the linac shielding upgrade, demonstrate that the additional shielding decreased the peripheral dose, expressed as a percentage of the delivered monitor units (MU), by a maximum of 59%. The dose reduction was greatest for cranial-caudal distances from the field edge less than 30 cm, and at these distances, the CyberKnife peripheral dose, expressed as a percentage of the delivered MU, is now comparable to that measured for the other treatment modalities in our previous investigation. For distances between 30 and 70 cm from the field edge, the additional shielding reduced the peripheral dose by between 20% and 55%. At these distances, the CyberKnife peripheral dose remains higher than doses measured in our previous study for the model C Gamma Knife and IMRT.

  9. [Application of robotized radiosurgical system CyberKnife for the treatment of neurosurgical patients].

    PubMed

    Konovalov, A N; Golanov, A V; Gorlachev, G E; Kornienko, V N; Trunin, Iu Iu; Kotel'nikova, T M; Zolotova, S V; Vetlova, E R; Galkin, M V; Antipina, N A; Mariashev, S A; Pronin, I N; Arutiunov, N V; Lubnin, A Iu; Iakovlev, S B

    2012-01-01

    Robotized system for radiosurgery CyberKnife (Accuray Inc., USA) is the first device dedicated and optimized for advanced irradiation during 1-7 fractions (i.e. radiosurgery and hypofractionation). CyberKnife is characterized by elaborate guidance system, high precision of dose delivery, possibility of conformal dose distributions with high gradient of target borderline dose which is most important in proximity of critical structures. The first CyberKnife system in Russia was installed in Burdenko Neurosurgery Institute. The paper presents 2-year experience of treating patients using CyberKnife. From April 2009 till October 2011 896 patients were treated using CyberKnife. Mean age was 48 years. Overall number of sessions was 2626. Radiosurgical procedures were performed in 21.8% of patients. 91% of cases were treated for intracranial lesions. Limited follow-up period in all kinds of pathology demonstrated results consistent with standard fractionation or radiosurgery. The rates of observed complications were also comparable with accepted techniques. CyberKnife system plays significant role in everyday activity of department of radiation therapy. In careful and thorough selection of patients it allows efficient and high-quality treatment of patients with neurosurgical diseases.

  10. Application of a cervical low incision in the functional neck dissection of thyroid papillary carcinoma.

    PubMed

    Xu, Jiajie; Chen, Chao; Zheng, Chuanming; Wang, Kejing; Shang, Jinbiao; Fang, Xianhua; Ge, Minghua; Tan, Zhuo

    2016-04-01

    The present study aimed to discuss the advantage of the application of a cervical low incision for functional neck dissection in patients with thyroid papillary carcinoma. The study was a retrospective analysis of 87 thyroid papillary carcinoma patients; cervical low incision in the functional neck dissection was applied for 47 cases and the classic 'L' incision was applied for 40 cases. The different integrity, surgical time, blood loss and the aesthetic property of the incision were compared between the cervical low incision and the classic 'L' incision for lateral neck dissection of thyroid cancer. The postoperative pathological diagnosis was that the average total amount and the region II lymph nodes of the unilateral neck dissection were 33 and 10 for the cervical low incision group, and 32 and 11 for the classic 'L' incision group, respectively (P>0.05). The average unilateral neck dissection times were 87 and 58 min for the cervical low incision group and the classic 'L' incision group, respectively (P<0.05). The blood loss of the cervical low incision group was 67 ml, while the loss for the classic 'L' incision group was 61 ml (P>0.05). The postoperative incision of the cervical low incision group was smaller and more concealing. Additionally, the cosmetic deformities were milder for an inconspicuous cervical scar, and the sensation was improved for the patients in comparison with the classic 'L' incision group. These results suggest that the application of cervical low incision for functional neck dissection in thyroid papillary carcinoma patients aids in reducing postoperative complications, without increasing recurrence rates. Therefore, the classic 'L' incision can be replaced by the cervical low incision.

  11. Application of a cervical low incision in the functional neck dissection of thyroid papillary carcinoma

    PubMed Central

    XU, JIAJIE; CHEN, CHAO; ZHENG, CHUANMING; WANG, KEJING; SHANG, JINBIAO; FANG, XIANHUA; GE, MINGHUA; TAN, ZHUO

    2016-01-01

    The present study aimed to discuss the advantage of the application of a cervical low incision for functional neck dissection in patients with thyroid papillary carcinoma. The study was a retrospective analysis of 87 thyroid papillary carcinoma patients; cervical low incision in the functional neck dissection was applied for 47 cases and the classic ‘L’ incision was applied for 40 cases. The different integrity, surgical time, blood loss and the aesthetic property of the incision were compared between the cervical low incision and the classic ‘L’ incision for lateral neck dissection of thyroid cancer. The postoperative pathological diagnosis was that the average total amount and the region II lymph nodes of the unilateral neck dissection were 33 and 10 for the cervical low incision group, and 32 and 11 for the classic ‘L’ incision group, respectively (P>0.05). The average unilateral neck dissection times were 87 and 58 min for the cervical low incision group and the classic ‘L’ incision group, respectively (P<0.05). The blood loss of the cervical low incision group was 67 ml, while the loss for the classic ‘L’ incision group was 61 ml (P>0.05). The postoperative incision of the cervical low incision group was smaller and more concealing. Additionally, the cosmetic deformities were milder for an inconspicuous cervical scar, and the sensation was improved for the patients in comparison with the classic ‘L’ incision group. These results suggest that the application of cervical low incision for functional neck dissection in thyroid papillary carcinoma patients aids in reducing postoperative complications, without increasing recurrence rates. Therefore, the classic ‘L’ incision can be replaced by the cervical low incision. PMID:27073645

  12. Relaxation in Physical Education Curricula.

    ERIC Educational Resources Information Center

    Coville, Claudia A.

    1979-01-01

    A theoretical framework for incorporating relaxation instruction in the physical education curriculum is presented based on the assumption that relaxation is a muscular-skeletal skill benefitting general motor skill acquisition. Theoretical principles, a definition of relaxation, and an analysis of stages of skill development are also used in the…

  13. A Comparison of Relaxation Strategies.

    ERIC Educational Resources Information Center

    Matthews, Doris B.

    Some researchers argue that all relaxation techniques produce a single relaxation response while others support a specific-effects hypothesis which suggests that progressive relaxation affects the musculoskeletal system and that guided imagery affects cognitive changes. Autogenics is considered a technique which is both somatic and cognitive. This…

  14. Relaxation from particle production

    NASA Astrophysics Data System (ADS)

    Hook, Anson; Marques-Tavares, Gustavo

    2016-12-01

    We consider using particle production as a friction force by which to implement a "Relaxion" solution to the electroweak hierarchy problem. Using this approach, we are able to avoid superplanckian field excursions and avoid any conflict with the strong CP problem. The relaxation mechanism can work before, during or after inflation allowing for inflationary dynamics to play an important role or to be completely decoupled.

  15. Relaxation from particle production

    SciTech Connect

    Hook, Anson; Marques-Tavares, Gustavo

    2016-12-20

    Here, we consider using particle production as a friction force by which to implement a “Relaxion” solution to the electroweak hierarchy problem. Using this approach, we are able to avoid superplanckian field excursions and avoid any conflict with the strong CP problem. The relaxation mechanism can work before, during or after inflation allowing for inflationary dynamics to play an important role or to be completely decoupled.

  16. Imaging and investigating the effects of incision angle of clear corneal cataract surgery with optical coherence tomography

    NASA Astrophysics Data System (ADS)

    Rao, Bin; Zhang, Jun; Taban, Mehran; McDonnell, Peter J.; Chen, Zhongping

    2003-12-01

    Effects of incision angle in construction of clear corneal cataract incision are studied with optical coherence tomography (OCT). A stable incision angle range is found to be existent for single-planed, clear corneal cataract incisions. When well pressurized, incision angles within this stable range result in well-apposed incision edges that resist gapping while incision angles falling outside this range have a larger tendency for wound leakage. It is also shown that a two-planed incision can effectively expand the stable range. For incision angles outside the stable range, the farther the incision angle is away from stable range, the larger the gap between incision wound edges when well pressurized. These findings emphasize the significance of incision construction to the self-sealing property of clear corneal cataract incisions. Finally, we demonstrate that OCT could be an effective modality for imaging and monitoring corneal surgery.

  17. Analysis of perioperative factors and cost comparison of single-incision and traditional multi-incision laparoscopic cholecystectomy.

    PubMed

    Beck, Catherine; Eakin, Jeffrey; Dettorre, Rebecca; Renton, David

    2013-01-01

    Recent technological advances in single-incision platforms have allowed many general surgeons to add single-incision laparoscopic cholecystectomy (SILC) to their armamentarium. However, adopting new surgical technologies comes at a cost to the patient and the surgeon. This study compared retrospective case-matched SILC and traditional multi-incision laparoscopic cholecystectomy (MILC) to evaluate the effects of SILC on perioperative outcomes and patient cost. The study compared 50 patients who underwent SILC with a case-matched population of individuals who underwent traditional MILC. The SILC technique was performed using one of three commercially available single-incision platforms currently used for single-incision laparoscopic surgery (SILS) cholecystectomies. All the SILS platforms were placed in a 2-cm supraumbilical incision. All statistical analyses were performed using Microsoft Excel 2008 for Macintosh, with statistical significance determined by a p value of 0.05 or less. The average operative time was 42 min for the SILC group and 45 min for the MILC group. The difference was not statistically significant. Similarly, the average estimated blood loss was 14 ml for the SILC group and 11 ml for the MILC group. Again, the difference was not statistically significant. Moreover, the body mass index (BMI) did not differ statistically between the SILC group (28.4 kg/m(2)) and the MILC group (32.2 kg/m(2)). The average patient cost was $18,447 for SILC and $17,701 for MILC, yielding a cost difference of $746. This difference was not statistically significant. At the authors' institution, SILS cholecystectomy was performed with blood loss, operating room time, and cost equal to that for MILC. Further research is necessary to assess the economic feasibility of SILC and the trade-off of cost with the improved cosmesis, decreased pain, greater patient satisfaction, reduced postoperative analgesic requirement, and faster return to work to determine the overall value

  18. Endoscopic submucosal tunnel dissection of upper gastrointestinal submucosal tumors: A comparative study of hook knife vs hybrid knife

    PubMed Central

    Zhou, Jie-Qiong; Tang, Xiao-Wei; Ren, Yu-Tang; Wei, Zheng-Jie; Huang, Si-Lin; Gao, Qiao-Ping; Zhang, Xiao-Feng; Yang, Jian-Feng; Gong, Wei; Jiang, Bo

    2017-01-01

    AIM To compare the efficacy and safety of a hook knife (HO) with a hybrid knife (HK) during endoscopic submucosal tunnel dissection (ESTD) procedure. METHODS Between August 2012 and December 2015, the ESTD procedure was performed for 83 upper GI submucosal lesions, which originated from the muscularis propria layer identified by upper endoscopy and endoscopic ultrasonography. Of these, 34 lesions were treated by a HO, whereas 49 lesions were treated by a HK. Data regarding age, gender, presenting symptoms, tumor location and size, procedure time, complications, en bloc resection rate and others were analyzed and compared between the two groups. RESULTS There were no significant differences in the age, gender, presenting symptoms and tumor location between the two groups. ESTD was successfully completed in all the patients, and no case was converted to laparoscopy. The mean procedure time was significantly shorter in the HK group than in the HO group (41.3 ± 20.3 min vs 57.2 ± 28.0 min, P = 0.004). The mean frequency of device exchange was 1.4 ± 0.6 in the HK group and significantly less than 3.3 ± 0.6 in the HO group (P < 0.001). The differences in tumor size and histopathological diagnoses were not significant between the two groups (P = 0.813, P = 0.363, respectively). Both groups had an equal en bloc resection rate and complete resection rate. Additionally, the complication rate was similar between the two groups (P = 0.901). During the follow-up, no recurrence occurred in either group. CONCLUSION We demonstrate for the first time that HO and HK do not differ in efficacy or safety, but HK reduces the frequency of device exchange and procedure time. PMID:28348490

  19. Single incision glove port laparoscopic colorectal cancer resection

    PubMed Central

    Joshi, HMN; Gosselink, MP; Adusumilli, S; Hompes, R; Cunningham, C; Lindsey, I

    2015-01-01

    Introduction The advantages of single port surgery remain controversial. This study was designed to evaluate the safety and feasibility of single incision glove port colon resections using a diathermy hook, reusable ports and standard laparoscopic straight instrumentation. Methods Between June 2012 and February 2014, 70 consecutive patients (30 women) underwent a colonic resection using a wound retractor and glove port. Forty patients underwent a right hemicolectomy through the umbilicus and thirty underwent attempted single port resection via an incision in the right rectus sheath (14 high anterior resection, 13 low anterior resection, 3 abdominoperineal resection). Results Sixty-two procedures (89%) were completed without conversion to open or multiport techniques. Four procedures had to be converted and additional ports were needed in four other patients. The postoperative mortality rate was 0%. Complications occurred in six patients (9%). Two cases were R1 while the remainder were R0 with a median nodal harvest of 20 (range: 9–48). The median length of hospital stay was 5 days (range: 3–25 days) (right hemicolectomy: 5 days (range: 3–12 days), left sided resection: 6 days (range: 4–25 days). At a median follow-up of 14 months, no port site hernias were observed. Conclusions Single incision glove port surgery is an appropriate technique for different colorectal cancer resections and has the advantage of being less expensive than surgery with commercial single incision ports. PMID:26263805

  20. Minimal incision surgery in strabismus: Modified fornix-based approach.

    PubMed

    Pérez-Flores, I

    2016-07-01

    To evaluate the modified fornix-based technique as an approach for minimal incision surgery in strabismus. The medical records of all consecutive patients that underwent strabismus surgery with fornix-based conjunctival incision between 2007 and 2012 were retrospectively reviewed. As a primary variable, an analysis was made of the wound size depending on the number of stitches. A descriptive study was performed on the variables related to patients and to the type of strabismus and surgery. Out of 153patients identified, 138 with 294 surgeries were included. In 200 (68%) interventions, the incision was sutured with one stitch, in 77 (26.2%) with 2, in 13 (4.4%) with 3, and in 4 (1.4%) with 4, with the mean number of stitches being 1.39±0.64. The mean age of the patients was 39years (2-80), and 36 (26.1%) had previous strabismus surgery, with topical anaesthesia being used in 35 (25.4%) cases. At 3months after surgery deviation was ≤10DP in 114 (82.6%) patients. There were no wound-related complications. The modified fornix-based technique is an effective and safe approach for minimal incision surgery in strabismus, in patients at all ages, with previous history of strabismus surgery and with topical anaesthesia. Copyright © 2015 Sociedad Española de Oftalmología. Published by Elsevier España, S.L.U. All rights reserved.

  1. Single-incision laparoscopic surgery for biliary tract disease

    PubMed Central

    Chuang, Shu-Hung; Lin, Chih-Sheng

    2016-01-01

    Single-incision laparoscopic surgery (SILS), or laparoendoscopic single-site surgery, has been employed in various fields to minimize traumatic effects over the last two decades. Single-incision laparoscopic cholecystectomy (SILC) has been the most frequently studied SILS to date. Hundreds of studies on SILC have failed to present conclusive results. Most randomized controlled trials (RCTs) have been small in scale and have been conducted under ideal operative conditions. The role of SILC in complicated scenarios remains uncertain. As common bile duct exploration (CBDE) methods have been used for more than one hundred years, laparoscopic CBDE (LCBDE) has emerged as an effective, demanding, and infrequent technique employed during the laparoscopic era. Likewise, laparoscopic biliary-enteric anastomosis is difficult to carry out, with only a few studies have been published on the approach. The application of SILS to CBDE and biliary-enteric anastomosis is extremely rare, and such innovative procedures are only carried out by a number of specialized groups across the globe. Herein we present a thorough and detailed analysis of SILC in terms of operative techniques, training and learning curves, safety and efficacy levels, recovery trends, and costs by reviewing RCTs conducted over the past three years and two recently updated meta-analyses. All existing literature on single-incision LCBDE and single-incision laparoscopic hepaticojejunostomy has been reviewed to describe these two demanding techniques. PMID:26811621

  2. Human repair endonuclease incises DNA at cytosine photoproducts

    SciTech Connect

    Gallagher, P.E.; Weiss, R.B.; Brent, T.P.; Duker, N.J.

    1987-05-01

    The nature of DNA damage by uvB and uvC irradiation was investigated using a defined sequence of human DNA. A UV-irradiated, 3'-end-labeled, 92 base pair sequence from the human alphoid segment was incubated with a purified human lymphoblast endonuclease that incises DNA at non-dimer photoproducts. Analysis by polyacrylamide gel electrophoresis identified all sites of endonucleolytic incision as cytosines. These were found in regions of the DNA sequence lacking adjacent pyrimidines and therefore are neither cyclobutane pyrimidine dimers nor 6-4'-pyrimidines. Incision at cytosine photoproducts was not detected at loci corresponding to alkali-labile sites in either control or irradiated substrates. This demonstrates that the bands detected after the enzymic reactions were not the result of DNA strand breaks, base loss sites or ring-opened cytosines. The optimal wavelengths for formation of cytosine photoproducts are 270-295 nm, similar to those associated with maximal tumor yields in animal ultraviolet carcinogenesis studies. Irradiation by monochromatic 254 nm light resulted in reduced cytosine photoproduct formation. This human UV endonuclease has an apparently identical substrate specificity to E. coli endonuclease III. Both the human and bacterial enzymes incise cytosine moieties in UV irradiated DNA and modified thymines in oxidized DNA.

  3. Time from uterine incision to delivery and hypoxic neonatal outcomes.

    PubMed

    Spain, Janine E; Tuuli, Methodius; Stout, Molly J; Roehl, Kimberly A; Odibo, Anthony O; Macones, George A; Cahill, Alison G

    2015-04-01

    The objective of this study was to estimate the association between time from uterine incision to delivery and hypoxic neonatal outcomes in nonanomalous term infants. All women undergoing in-labor term cesarean deliveries (CDs) in the first 2 years of an ongoing prospective cohort study were included. The primary exposure was time in seconds from uterine incision to delivery. The primary outcome was a composite of hypoxia-associated neonatal outcomes, defined as at least one of: seizures, hypoxic ischemic encephalopathy, need for hypothermia treatment, and death within 7 days. Of 812 patients who underwent in-labor CD, the composite hypoxia outcome occurred in 18 (2.2%) neonates. There was no significant difference in the rate of hypoxic morbidity with increasing increments of 60 seconds from uterine incision to delivery (p = 0.35). There was a significantly increased risk of hypoxic morbidity in those delivered in the highest quintile (>240 seconds) compared with those in the lowest quintile (≤ 60 seconds) in cesareans performed for an indication other than nonreassuring fetal status (relative risk, 5.58; 95% confidence interval, 1.30-23.91). Overall, duration from uterine incision to delivery for in-labor cesareans of nonanomalous term infants was not associated with an increase in risk of hypoxia-associated morbidities. Thieme Medical Publishers 333 Seventh Avenue, New York, NY 10001, USA.

  4. Time between skin incision and delivery during cesarean.

    PubMed

    Rossouw, Jana N; Hall, David; Harvey, Justin

    2013-04-01

    To investigate factors influencing skin incision-to-delivery time (including sub-divisions thereof) and the effect of these surgical intervals on immediate neonatal outcome. A prospective cohort analysis was conducted of all women undergoing cesarean delivery at Tygerberg Hospital, Cape Town, South Africa, from May 24 to November 2, 2010. Three surgical intervals were evaluated: skin incision to myometrium, myometrium to delivery, and skin incision to delivery. Neonatal outcome was assessed by the 5-minute Apgar score. Of 1120 cesarean deliveries recorded during the study period, 77.2% were emergency procedures, which were performed more quickly at all surgical planes (P<0.01). Adhesions in the surgical field were present in 7.4% of all primary procedures versus 67.7% of all third procedures (P<0.001). The skin incision-to-delivery time was significantly extended among repeat procedures (P<0.001) and increased progressively with degree of obesity (P<0.001). Although the 3 surgical intervals were calculated individually, none of the median values correlated with a 5-minute Apgar score below 7 for emergency deliveries. Repeat procedures, adhesions, and obesity prolonged the time taken for cesarean delivery. Nevertheless, the effect of these factors on the 5-minute Apgar score was minimal. Copyright © 2013 International Federation of Gynecology and Obstetrics. Published by Elsevier Ireland Ltd. All rights reserved.

  5. Reconstructive subperiosteal midface lift: A three nonvisible incision approach.

    PubMed

    Sales-Sanz, Marco; Barrancos, Constanza; Won-Kim, Hae-Ryung; Sales-Sanz, Andrea; Colmenero, César

    2017-10-01

    This article describes our surgical technique for subperiosteal midface elevation in patients with paralytic lower eyelid malposition or cicatricial inferior eyelid retraction. Nineteen patients with paralytic lower eyelid malposition and 15 patients with cicatricial inferior eyelid retraction underwent a subperiosteal midface lift (n = 34). The procedure was performed under local anesthesia through three nonvisible incisions. A transconjunctival incision allows preseptal dissection to the orbital rim, followed by a subperiosteal dissection of the midface. An oral incision is useful to achieve complete subperiosteal dissection and to perform the distal periostomy, which allows complete release of the midface soft tissues. A temporal incision provides access to the temporal fascia for fixation of the elevated tissues and gives the surgeon the possibility of removing redundant skin from the scalp instead of the lower eyelid. Additional posterior lamellar grafting was performed in 24 patients. There was a statistically significant reduction in the distance from the pupil centre to the lower eyelid (margin reflex distance, MRD2) 1 month after surgery (preoperative MRD2 9.62 ± 4.52 mm, postoperative MRD2 5.28 ± 2.62 mm). The ectropion and lower eyelid retraction was resolved in all patients, except for one recurrence. Midfacial elevation is a safe and effective surgical technique in the treatment of static lower eyelid malposition after chronic facial nerve palsy or posttraumatic or iatrogenic lower eyelid retraction.

  6. Single-incision pediatric endosurgery in newborns and infants

    PubMed Central

    Kozlov, Yury; Novozhilov, Vladimir; Baradieva, Polina; Krasnov, Pavel; Kovalkov, Konstantin; Muensterer, Oliver J

    2015-01-01

    This study focuses on the successful application of single-incision pediatric endosurgery in the treatment of congenital anomalies and acquired diseases in neonates and infants. The purpose of this scientific review consists in highlighting the spectrum, indications, applicability, and effectiveness of single-port endosurgery in children during the first 3 postnatal months. PMID:26566478

  7. Fontan operation for the Cantrell syndrome using a clamshell incision.

    PubMed

    Ito, Hiroki; Ota, Noritaka; Murata, Masaya; Sakamoto, Kisaburo

    2013-10-01

    A median sternotomy could be difficult for a child with ectopia cordis and complex congenital cardiac anomalies. We report a patient with ectopia cordis, functionally single ventricle and bilateral superior vena cava, who underwent a staged Fontan procedure through a clamshell incision and the sternothoracotomy approach.

  8. Fontan operation for the Cantrell syndrome using a clamshell incision

    PubMed Central

    Ito, Hiroki; Ota, Noritaka; Murata, Masaya; Sakamoto, Kisaburo

    2013-01-01

    A median sternotomy could be difficult for a child with ectopia cordis and complex congenital cardiac anomalies. We report a patient with ectopia cordis, functionally single ventricle and bilateral superior vena cava, who underwent a staged Fontan procedure through a clamshell incision and the sternothoracotomy approach. PMID:23814137

  9. "Scleral tunnel incision"-trabeculectomy with one releasable suture.

    PubMed

    Vuori, M L; Viitanen, T

    2001-06-01

    To describe a modified surgical technique, a scleral tunnel incision- trabeculectomy (STIT) and evaluate its safety and efficacy in lowering IOP in glaucoma patients. One hundred and three patients were included in a retrospective, nonrandomized clinical study. Fifty-three patients were operated conventionally and 40 patients underwent STIT. In the modified technique the sides of the scleral flap are opened only half-way to the limbus and the flap is closed with a single releasable "slipknot"-suture. The mean IOP on the first postoperative day was 4.5 +/- 6.8 mmHg in the conventional group and 7.4 +/- 7.1 mmHg in the tunnel incision group (p = 0.012). On the second postoperative day the mean IOP was 4.5 +/- 7.3 mmHg and 6.3 +/- 6.5 mmHg in the conventional group and tunnel incision group, respectively (p = 0.065). There was no statistically significant difference in the mean postoperative IOP between the groups at one month and at 6-12 months. Shallow anterior chamber and iridocorneal touch occurred statistically significantly less in the tunnel incision group than in the conventional group. STIT appears to be equivalent to conventional trabeculectomy (CT) in lowering IOP during the first 6-12 months postoperatively. It is also relatively safe and has fewer early complications related to excessive aqueous outflow than CT.

  10. Observation of Phase Objects by Using an X-ray Microscope with a Foucault Knife-Edge

    NASA Astrophysics Data System (ADS)

    Watanabe, N.; Sasaya, T.; Imai, Y.; Iwata, S.; Zama, K.; Aoki, S.

    2011-09-01

    An x-ray microscope with a zone plate was assembled at the synchrotron radiation source of BL3C, Photon Factory. A Foucault knife-edge was set at the back focal plate of the objective zone plate and phase retrieval was tested by scanning the knife-edge. A preliminary result shows that scanning the knife-edge during exposure was effective for phase retrieval. Phase-contrast tomography was investigated using differential projection images calculated from two Schlieren images with the oppositely oriented knife-edges. Fairly good reconstruction images of polystyrene beads and spores could be obtained.

  11. Observation of Phase Objects by Using an X-ray Microscope with a Foucault Knife-Edge

    SciTech Connect

    Watanabe, N.; Sasaya, T.; Imai, Y.; Iwata, S.; Zama, K.; Aoki, S.

    2011-09-09

    An x-ray microscope with a zone plate was assembled at the synchrotron radiation source of BL3C, Photon Factory. A Foucault knife-edge was set at the back focal plate of the objective zone plate and phase retrieval was tested by scanning the knife-edge. A preliminary result shows that scanning the knife-edge during exposure was effective for phase retrieval. Phase-contrast tomography was investigated using differential projection images calculated from two Schlieren images with the oppositely oriented knife-edges. Fairly good reconstruction images of polystyrene beads and spores could be obtained.

  12. Late Quaternary rates of stream incision in Northeast Peloponnese, Greece

    NASA Astrophysics Data System (ADS)

    Karymbalis, Efthimios; Papanastassiou, Dimitrios; Gaki-Papanastassiou, Kalliopi; Ferentinou, Maria; Chalkias, Christos

    2016-09-01

    This study focuses on defining rates of fluvial incision for the last 580±5 kyr along valley systems of eight streams that drain the eastern part of the northern Peloponnese. The streams are developed on the uplifted block of the offshore-running Xylokastro normal fault, one of the main faults bounding the southern edge of the Gulf of Corinth half-graben, and have incised a set of ten uplifted marine terraces having an amphitheatric shape. These terraces range in age from 60±5 kyr to 580±5 kyr and have been mapped in detail and correlated with late Pleistocene oxygen-isotope stages of high sea-level stands by previous studies. The terraces were used in this paper as reference surfaces in order to define fluvial incision rates at the lower reaches of the studied streams. To evaluate incision rates, thirty-three topographic valley cross-sections were drawn using fieldwork measurements as well as using a highly accurate (2×2 cell size) Digital Elevation Model (DEM) at specific locations where streams cut down the inner edges of the marine terraces. For each cross-section the ratio of valley floor width to valley height (Vf) and long-term mean stream incision rates were estimated for the last 580±5 kyr, while rock uplift rates were estimated for the last 330±5 kyr. The geomorphic evolution of the valleys on the uplifted block of the Xylokastro fault has been mainly driven by the lithology of the bedrock, sea level fluctuations during the late Quaternary, and incision of the channels due to the tectonic uplift. Stream incision rates range from 0.10±0.1 mm/yr for the last 123±7 kyr to 1.14±0.1 mm/yr for the last 310±5 kyr and are gradually greater from east to west depending on the distance from the trace of the fault. Downcutting rates are comparable with the rock uplift rates, which range from 0.4±0.02 mm/yr to 1.49±0.12 mm/yr, over the last 330±5 kyr.

  13. Quantified Incision Placement for Postseptal Approach Transconjunctival Blepharoplasty.

    PubMed

    Undavia, Satyen; Briceño, César A; Massry, Guy G

    2016-01-01

    This study quantifies the incision location in transconjunctival lower eyelid blepharoplasty to optimize postspetal (direct) access to the eyelid/orbital fat. A retrospective chart review of patients undergoing transconjunctival blepharoplasty by one surgeon (GGM) from January 2013 to January 2014 was performed. Simultaneous globe retropulsion and lower eyelid inferior displacement was used to balloon the conjunctiva forward to maximally visualize the transconjunctival surface anatomical landmarks of importance. A caliper was used to measure the distance in millimeters from the inferior tarsus to the most superior projection of visible fat. The conjunctival incision was made 0.5 mm posterior to this measured distance. For each procedure it was noted whether the preseptal or postseptal plane was entered. Sixty-six patients were assessed. Fifty patients were women, and the mean patient age was 54 years (range 36-71 years). The mean distance from the inferior tarsus to the visualized superior tip of fat was 6.03 mm (range 5-7 mm) and the mean incision placement was 6.53 mm (range 5.5-7.5 mm). The postseptal space (direct access to fat) was entered in 54 cases (82%). The inferior vascular arcade was identified in 23 cases (35%) cases. In this instance, the incision was placed below this landmark in 16 cases (70%). There were 5 cases (7.6%) of postoperative chemosis which all resolved within 2 months with conservative measures. There were no other complications related to the conjunctival incision. Placing the conjunctival incision for postseptal approach transconjunctival blepharoplasty 0.5 mm posterior to the most superior projection of clinically visible fat (with adjunctive globe retropulsion and lower eyelid infraplacement) accesses the postspetal space directly in 82% of cases. Previously suggested incision placements: between 2 and 5 mm below the tarsus, at the fornix, or at the inferior vascular arcade are subjective/anecdotal at best and without

  14. Gamma Knife radiosurgery with CT image-based dose calculation.

    PubMed

    Xu, Andy Yuanguang; Bhatnagar, Jagdish; Bednarz, Greg; Niranjan, Ajay; Kondziolka, Douglas; Flickinger, John; Lunsford, L Dade; Huq, M Saiful

    2015-11-08

    The Leksell GammaPlan software version 10 introduces a CT image-based segmentation tool for automatic skull definition and a convolution dose calculation algorithm for tissue inhomogeneity correction. The purpose of this work was to evaluate the impact of these new approaches on routine clinical Gamma Knife treatment planning. Sixty-five patients who underwent CT image-guided Gamma Knife radiosurgeries at the University of Pittsburgh Medical Center in recent years were retrospectively investigated. The diagnoses for these cases include trigeminal neuralgia, meningioma, acoustic neuroma, AVM, glioma, and benign and metastatic brain tumors. Dose calculations were performed for each patient with the same dose prescriptions and the same shot arrangements using three different approaches: 1) TMR 10 dose calculation with imaging skull definition; 2) convolution dose calculation with imaging skull definition; 3) TMR 10 dose calculation with conventional measurement-based skull definition. For each treatment matrix, the total treatment time, the target coverage index, the selectivity index, the gradient index, and a set of dose statistics parameters were compared between the three calculations. The dose statistics parameters investigated include the prescription isodose volume, the 12 Gy isodose volume, the minimum, maximum and mean doses on the treatment targets, and the critical structures under consideration. The difference between the convolution and the TMR 10 dose calculations for the 104 treatment matrices were found to vary with the patient anatomy, location of the treatment shots, and the tissue inhomogeneities around the treatment target. An average difference of 8.4% was observed for the total treatment times between the convolution and the TMR algorithms. The maximum differences in the treatment times, the prescription isodose volumes, the 12 Gy isodose volumes, the target coverage indices, the selectivity indices, and the gradient indices from the convolution

  15. Gamma Knife radiosurgery with CT image-based dose calculation.

    PubMed

    Xu, Andy Yuanguang; Bhatnagar, Jagdish; Bednarz, Greg; Niranjan, Ajay; Kondziolka, Douglas; Flickinger, John; Lunsford, L Dade; Huq, M Saiful

    2015-11-01

    The Leksell GammaPlan software version 10 introduces a CT image-based segmentation tool for automatic skull definition and a convolution dose calculation algorithm for tissue inhomogeneity correction. The purpose of this work was to evaluate the impact of these new approaches on routine clinical Gamma Knife treatment planning. Sixty-five patients who underwent CT image-guided Gamma Knife radiosurgeries at the University of Pittsburgh Medical Center in recent years were retrospectively investigated. The diagnoses for these cases include trigeminal neuralgia, meningioma, acoustic neuroma, AVM, glioma, and benign and metastatic brain tumors. Dose calculations were performed for each patient with the same dose prescriptions and the same shot arrangements using three different approaches: 1) TMR 10 dose calculation with imaging skull definition; 2) convolution dose calculation with imaging skull definition; 3) TMR 10 dose calculation with conventional measurement-based skull definition. For each treatment matrix, the total treatment time, the target coverage index, the selectivity index, the gradient index, and a set of dose statistics parameters were compared between the three calculations. The dose statistics parameters investigated include the prescription isodose volume, the 12 Gy isodose volume, the minimum, maximum and mean doses on the treatment targets, and the critical structures under consideration. The difference between the convolution and the TMR 10 dose calculations for the 104 treatment matrices were found to vary with the patient anatomy, location of the treatment shots, and the tissue inhomogeneities around the treatment target. An average difference of 8.4% was observed for the total treatment times between the convolution and the TMR algorithms. The maximum differences in the treatment times, the prescription isodose volumes, the 12 Gy isodose volumes, the target coverage indices, the selectivity indices, and the gradient indices from the convolution

  16. Interneural and intervascular extension for increased exposure in midline vertical incisions.

    PubMed

    Rizzo, P

    1986-08-01

    In instances in which wide upper lateral abdominal exposure is required, standard midline incisions are occasionally inadequate. The typical invered "U" incision violates the nerve and blood supply to the abdominal wall. An interneural and intervascular incision which is used either as an extension of the midline incision or bilaterally as the primary incision is described herein. The interneural and intervascular extension begins at the costal margin and curves medially with severance of the full thickness abdominal wall to join the vertical midline incision. This extension raises a triangular flap of abdominal wall with a base on the costal cartilage and apex at the junction of the two incisions. In a series of seven patients, no interneural and intervascular incision resulted in wound hernia or delayed wound healing postoperatively. This approach provides superior lateral abdominal exposure and by paralleling nerve and vascular distribution, follows sound anatomic principles for minimizing pain and promoting subsequent wound healing.

  17. Incision of the Jezero Crater Outflow Channel by Fluvial Sediment Transport

    NASA Astrophysics Data System (ADS)

    Holo, S. J.; Kite, E. S.

    2017-10-01

    We developed a simple model of channel incision of the Jezero Crater outflow channel in which channel incision occurs contemporaneously with lake filling. The timescales required to erode the channel are comparable to the lake filling timescales.

  18. 357 Gamma Knife Stereotactic Radiosurgery in the Management of Large Cerebral Arteriovenous Malformations.

    PubMed

    Singh, Manmohan; Aggarwal, Deepak; Kale, Shashank Sharad

    2016-08-01

    Large brain arteriovenous malformations (AVMs) pose management challenge in neurosurgical practice. Management remains conservative unless these AVMs bleed or present with neurological deficits. For patients who require treatment, options are limited with very high treatment-related morbidity. Gamma knife radiosurgery remains an excellent noninvasive option for such AVMs. This is a retrospective study of 74 patients with large AVMs who were treated with gamma knife radiosurgery over 16 years. Sixty-five patients were treated with single-fraction and 9 patients were treated with volume-staged gamma knife radiosurgery. Average follow-up was 4.2 years. In the single-fraction group, 90% patients had SM grade 3 and 4 AVMs while 10% patients had SM grade 5 AVMs. Mean marginal radiation dose was 23.66 Gy. Overall obliteration rate of 66% was observed. Four percent of patients rebled in this group. Postradiation edema was observed in 18% of patient who presented with headache, new-onset seizures, and motor deficits. The symptoms improved with steroid therapy in most patients. Delayed cyst formations were seen in 2 patients. Interestingly, 41% patients showed seizure control after gamma knife radiosurgery. In volume-staging group, 60% patients had SM grade 4 AVMs and 40% patients has SM grade 5 AVMs. All patients were treated in 2 sittings. Average marginal dose used was 23 Gy. These patients showed nearly 80% reduction in the nidus volume at follow-up. No new-onset deficit was observed in this group, and all patients tolerated the treatment very well. Large-volume AVMs can be managed with gamma knife radiosurgery with acceptable risks. Single-fraction gamma knife radiosurgery should be considered for moderate-size AVMs away from critical structures. Large-volume lesions should be treated with volume-staged gamma knife radiosurgery.

  19. Knife inflicted penetrating injuries of the maxillofacial region: a descriptive, record-based study.

    PubMed

    Meer, M; Siddiqi, A; Morkel, J A; Janse van Rensburg, P; Zafar, S

    2010-01-01

    Penetrating knife injuries of the face are more common in South Africa than the rest of the world. These injuries can be life-threatening, especially where the major blood vessels of the face are involved. The approach to treatment should be multidisciplinary, beginning with the trauma unit to provide airway maintenance and haemodynamic stabilisation. An interventional radiologist may be consulted for angiography. The aim of the present study was to retrospectively analyse all cases of knife-inflicted penetrating injuries to the maxillofacial region with the knife in situ and subsequently develop a management protocol to be used by maxillofacial surgery registrars when presented with such cases. It was a retrospective, cross-sectional and record-based study, analysing all penetrating knife injuries reported at various hospitals for a period of 11 years. In this study, 24 cases of knife injuries were analysed. Twenty-one patients (87.5%) in this series were male and three (12.5%) were female. Of these 24 patients, 13 (54.2%) were coloured and 11 (45.8%) were black. There were no white or Indian patients. Post-surgical recovery of all patients was rapid and uneventful, and there were no fatalities. Patients with knife injuries to the face with no definite signs of vascular injury can thus be safely and accurately managed on the basis of physical examination and plain-film radiography. An angiogram is mandatory if the patient presents with excessive bleeding, an expanding haematoma or if the knife blade is in the region of any large vessels.

  20. Endoscopic submucosal dissection for superficial esophageal neoplasms using the stag beetle knife.

    PubMed

    Fujinami, H; Hosokawa, A; Ogawa, K; Nishikawa, J; Kajiura, S; Ando, T; Ueda, A; Yoshita, H; Sugiyama, T

    2014-01-01

    Endoscopic submucosal dissection (ESD) is an accepted standard treatment for early gastric cancer but is not widely used in the esophagus because of technical difficulties. To increase the safety of esophageal ESD, we used a scissors-type device called the stag beetle (SB) knife. The aim of this study was to determine the efficacy and safety of ESD using the SB knife. We performed a single-center retrospective, uncontrolled trial. A total of 38 lesions were excised by ESD from 35 consecutive patients who were retrospectively divided into the following two groups according to the type of knife used to perform ESD: the hook knife (hook group) was used in 20 patients (21 lesions), and the SB knife (SB group) was used in 15 patients (17 lesions). We evaluated and compared the operative time, lesion size, en bloc resection rate, pathological margins free rate, and complication rate in both groups. The operative time was shorter in the SB group (median 70.0 minutes [interquartile range, 47.5-87.0]) than in the hook group (92.0 minutes [interquartile range, 63.0-114.0]) (P = 0.019), and the rate of complications in the SB group was 0% compared with 45.0% in the hook group (P = 0.004). However, the lesion size, en bloc resection rate, and pathological margins free rate did not differ significantly between the two groups. In conclusion, ESD using the SB knife was safer than that using a conventional knife for superficial esophageal neoplasms.

  1. Size reduction of high- and low-moisture corn stalks by linear knife grid system

    SciTech Connect

    Womac, A.R.; Igathinathane, C.; Sokhansanj, Shahabaddine; Narayan, S.

    2009-04-01

    High- and low-moisture corn stalks were tested using a linear knife grid size reduction device developed for first-stage size reduction. The device was used in conjunction with a universal test machine that quantified shearing stress and energy characteristics for forcing a bed of corn stalks through a grid of sharp knives. No published engineering performance data for corn stover with similar devices are available to optimize performance; however, commercial knife grid systems exist for forage size reduction. From the force displacement data, mean and maximum ultimate shear stresses, cumulative and peak mass-based cutting energies for corn stalks, and mean new surface area-based cutting energies were determined from 4 5 refill runs at two moisture contents (78.8% and 11.3% wet basis), three knife grid spacings (25.4, 50.8, and 101.6 mm), and three bed depths (50.8, 101.6, and 152.4 mm). In general, the results indicated that peak failure load, ultimate shear stress, and cutting energy values varied directly with bed depth and inversely with knife grid spacing. Mean separation analysis established that high- and low-moisture conditions and bed depths 101.6 mm did not differ significantly (P < 0.05) for ultimate stress and cutting energy values, but knife grid spacing were significantly different. Linear knife grid cutting energy requirements for both moisture conditions of corn stalks were much smaller than reported cutting energy requirements. Ultimate shear stress and cutting energy results of this research should aid the engineering design of commercial scale linear knife gird size reduction equipment for various biomass feedstocks.

  2. Progressive muscle relaxation, yoga stretching, and ABC relaxation theory.

    PubMed

    Ghoncheh, Shahyad; Smith, Jonathan C

    2004-01-01

    This study compared the psychological effects of progressive muscle relaxation (PMR) and yoga stretching (hatha) exercises. Forty participants were randomly divided into two groups and taught PMR or yoga stretching exercises. Both groups practiced once a week for five weeks and were given the Smith Relaxation States Inventory before and after each session. As hypothesized, practitioners of PMR displayed higher levels of relaxation states (R-States) Physical Relaxation and Disengagement at Week 4 and higher levels of Mental Quiet and Joy as a posttraining aftereffect at Week 5. Contrary to what was hypothesized, groups did not display different levels of R-States Energized or Aware. Results suggest the value of supplementing traditional somatic conceptualizations of relaxation with the psychological approach embodied in ABC relaxation theory. Clinical and research implications are discussed.

  3. Differentiable McCormick relaxations

    DOE PAGES

    Khan, Kamil A.; Watson, Harry A. J.; Barton, Paul I.

    2016-05-27

    McCormick's classical relaxation technique constructs closed-form convex and concave relaxations of compositions of simple intrinsic functions. These relaxations have several properties which make them useful for lower bounding problems in global optimization: they can be evaluated automatically, accurately, and computationally inexpensively, and they converge rapidly to the relaxed function as the underlying domain is reduced in size. They may also be adapted to yield relaxations of certain implicit functions and differential equation solutions. However, McCormick's relaxations may be nonsmooth, and this nonsmoothness can create theoretical and computational obstacles when relaxations are to be deployed. This article presents a continuously differentiablemore » variant of McCormick's original relaxations in the multivariate McCormick framework of Tsoukalas and Mitsos. Gradients of the new differentiable relaxations may be computed efficiently using the standard forward or reverse modes of automatic differentiation. Furthermore, extensions to differentiable relaxations of implicit functions and solutions of parametric ordinary differential equations are discussed. A C++ implementation based on the library MC++ is described and applied to a case study in nonsmooth nonconvex optimization.« less

  4. Differentiable McCormick relaxations

    SciTech Connect

    Khan, Kamil A.; Watson, Harry A. J.; Barton, Paul I.

    2016-05-27

    McCormick's classical relaxation technique constructs closed-form convex and concave relaxations of compositions of simple intrinsic functions. These relaxations have several properties which make them useful for lower bounding problems in global optimization: they can be evaluated automatically, accurately, and computationally inexpensively, and they converge rapidly to the relaxed function as the underlying domain is reduced in size. They may also be adapted to yield relaxations of certain implicit functions and differential equation solutions. However, McCormick's relaxations may be nonsmooth, and this nonsmoothness can create theoretical and computational obstacles when relaxations are to be deployed. This article presents a continuously differentiable variant of McCormick's original relaxations in the multivariate McCormick framework of Tsoukalas and Mitsos. Gradients of the new differentiable relaxations may be computed efficiently using the standard forward or reverse modes of automatic differentiation. Furthermore, extensions to differentiable relaxations of implicit functions and solutions of parametric ordinary differential equations are discussed. A C++ implementation based on the library MC++ is described and applied to a case study in nonsmooth nonconvex optimization.

  5. Commissioning of the Leksell Gamma Knife(®) Icon™.

    PubMed

    Zeverino, Michele; Jaccard, Maud; Patin, David; Ryckx, Nick; Marguet, Maud; Tuleasca, Constantin; Schiappacasse, Luis; Bourhis, Jean; Levivier, Marc; Bochud, Francois O; Moeckli, Raphaël

    2017-02-01

    The Leksell Gamma Knife (LGK) Icon has been recently introduced to provide Gamma Knife technology with frameless stereotactic treatments which use an additional cone-beam CT (CBCT) imaging system and a motion tracking system (IFMM, Intra-Fraction Motion Management). The system was commissioned for the treatment unit itself as well as the imaging system. The LGK Icon was calibrated using an A1SL ionization chamber. EBT3 radiochromic films were employed to independently check the machine calibration, to measure the relative output factors (ROFs) and to collect dose distributions. Coincidence between CBCT isocenter and radiological focus was evaluated by means of EBT3 films. CBCT image quality was investigated in terms of spatial resolution, contrast-to-noise ratio (CNR), and uniformity for the two presets available (low dose and high dose). Computed Tomography Dose Index (CTDI) was also measured for both presets. The absolute dose rate of the LGK Icon was 3.86 ± 0.09 Gy/min. This result was confirmed by EBT3 readings. ROF were found to be 0.887 ± 0.035 and 0.797 ± 0.032 for the 8 mm and 4 mm collimators, respectively, which are within 2% of the Monte Carlo-derived ROF values. Excellent agreement was found between calculated and measured dose distribution with the gamma pass rate >95% of points for the nine dose distributions analyzed with 3%/1 mm criteria. CBCT isocenter was found to be within 0.2 mm with respect to radiological focus. Image quality parameters were found to be well within the manufacturer's specifications with the high-dose preset being superior in terms of CNR and uniformity. CTDI values were 2.41 mGy and 6.32 mGy, i.e. -3.6% and 0.3% different from the nominal values for the low-dose and high-dose presets, respectively. The LGK Icon was successfully commissioned for clinical use. The use of the EBT3 to characterize the treatment unit was demonstrated to be feasible. The CBCT imaging system operates well within the manufacturer's specifications

  6. Air kerma based dosimetry calibration for the Leksell Gamma Knife

    SciTech Connect

    Meltsner, Sheridan Griffin; DeWerd, Larry A.

    2009-02-15

    No accepted official protocol exists for the dosimetry of the Leksell Gamma Knife registered (GK) stereotactic radiosurgery device. Establishment of a dosimetry protocol has been complicated by the unique partial-hemisphere arrangement of 201 individual {sup 60}Co beams simultaneously focused on the treatment volume and by the rigid geometry of the GK unit itself. This article proposes an air kerma based dosimetry protocol using either an in-air or in-acrylic phantom measurement to determine the absorbed dose rate of fields of the 18 mm helmet of a GK unit. A small-volume air ionization chamber was used to make measurements at the physical isocenter of three GK units. The absorbed dose rate to water was determined using a modified version of the AAPM Task Group 21 protocol designed for use with {sup 60}Co-based teletherapy machines. This experimentally determined absorbed dose rate was compared to the treatment planning system (TPS) absorbed dose rate. The TPS used with the GK unit is Leksell GammaPlan. The TPS absorbed dose rate at the time of treatment is the absorbed dose rate determined by the physicist at the time of machine commissioning decay corrected to the treatment date. The TPS absorbed dose rate is defined as absorbed dose rate to water at the isocenter of a water phantom with a radius of 8 cm. Measurements were performed on model B and C Gamma Knife units. The absorbed dose rate to water for the 18 mm helmet determined using air-kerma based calculations is consistently between 1.5% and 2.9% higher than the absorbed dose rate provided by the TPS. These air kerma based measurements allow GK dosimetry to be performed with an established dosimetry protocol and without complications arising from the use of and possible variations in solid phantom material. Measurements were also made with the same ionization chamber in a spherical acrylic phantom for comparison. This methodology will allow further development of calibration methods appropriate for the

  7. Results of gamma knife surgery for Cushing's disease.

    PubMed

    Sheehan, Jason P; Xu, Zhiyuan; Salvetti, David J; Schmitt, Paul J; Vance, Mary Lee

    2013-12-01

    Cushing's disease is a challenging neuroendocrine disorder. Although resection remains the primary treatment option for most patients, the disease persists if there is residual or recurrent tumor. Stereotactic radiosurgery has been used to treat patients with persistent Cushing's disease after a prior resection. The authors report on the long-term risks and benefits of radiosurgery for Cushing's disease. A retrospective review of a prospectively collected database of radiosurgery patients was undertaken at the University of Virginia. All patients with Cushing's disease treated with Gamma Knife surgery (GKS) were identified. Those without at least 12 months of clinical and radiological follow-up were excluded from this analysis. Rates of endocrine remission, tumor control, and adverse events were assessed. Statistical methods were used to identify favorable and unfavorable prognostic factors. Ninety-six patients with the required follow-up data were identified. The mean tumor margin dose was 22 Gy. The median follow-up was 48 months (range 12-209.8 months). At the last follow-up, remission of Cushing's disease occurred in 70% of patients. The median time to remission among all patients was 16.6 months (range 1-165.7 months). The median time to remission in those who had temporarily stopped taking ketoconazole at the time of GKS was 12.6 months, whereas it was 21.8 months in those who continued to receive ketoconazole (p < 0.012). Tumor control was achieved in 98% of patients. New loss of pituitary function occurred in 36% of patients. New or worsening cranial neuropathies developed in 5 patients after GKS, with the most common involving cranial nerves II and III. Gamma Knife surgery offers a high rate of tumor control and a reasonable rate of endocrine remission in patients with Cushing's disease. The cessation of cortisol-lowering medications around the time of GKS appears to result in a more rapid rate of remission. Delayed hypopituitarism and endocrine recurrence

  8. Grueneisen Relaxation Photoacoustic Microscopy

    NASA Astrophysics Data System (ADS)

    Wang, Lidai; Zhang, Chi; Wang, Lihong V.

    2014-10-01

    The temperature-dependent property of the Grueneisen parameter has been employed in photoacoustic imaging mainly to measure tissue temperature. Here we explore this property using a different approach and develop Grueneisen relaxation photoacoustic microscopy (GR-PAM), a technique that images nonradiative absorption with confocal optical resolution. GR-PAM sequentially delivers two identical laser pulses with a microsecond-scale time delay. The first laser pulse generates a photoacoustic signal and thermally tags the in-focus absorbers. When the second laser pulse excites the tagged absorbers within the thermal relaxation time, a photoacoustic signal stronger than the first one is produced, owing to the temperature dependence of the Grueneisen parameter. GR-PAM detects the amplitude difference between the two colocated photoacoustic signals, confocally imaging the nonradiative absorption. We greatly improved axial resolution from 45 μm to 2.3 μm and, at the same time, slightly improved lateral resolution from 0.63 μm to 0.41 μm. In addition, the optical sectioning capability facilitates the measurement of the absolute absorption coefficient without fluence calibration.

  9. Effects of incising on treatability and leachability of CCA-C-treated eastern hemlock

    Treesearch

    S. Nami Kartal

    2002-01-01

    Incising is used to increase exposed wood surface and improve uptake and penetration of preservative during pressure treatment of refractory species. However, incising may also cause increased leaching of preservative when the wood is placed in service. This study compared the rate of leaching from unincised eastern hemlock to that of wood that had been incised to two...

  10. Channel incision and suspended sediment delivery at Caspar Creek, Mendocino County, California

    Treesearch

    Nicholas J. Dewey; Thomas E. Lisle; Leslie M. Reid

    2003-01-01

    Tributary and headwater valleys in the Caspar Creek watershed,in coastal Mendocino County, California,show signs of incision along much of their lengths.An episode of incision followed initial-entry logging which took place between 1860 and 1906. Another episode of incision cut into skid-trails created for second-entry logging in the 1970's.

  11. What can we learn from fluvial incision in high mountains?

    NASA Astrophysics Data System (ADS)

    Fuchs, Margret; Gloaguen, Richard; Krbetschek, Matthias

    2013-04-01

    High and actively deforming mountain ranges attract the attention of geoscientists as they provide natural laboratories of fast evolving process-response systems. Tectonic compressional settings, often linked to perpendicular extension, control the topographic growth and hence, erosion, transport pathways and sedimentation. High altitude differences within short horizontal distances promote material re-organisation and high rates of surface processes. Furthermore, high mountains constitute orographic barriers that affect atmospheric circulations as well as host different climate regimes similar to those of widely separated latitudinal belts. Both cause a high sensitivity of surface processes to changes in climatic conditions. However, feedbacks between climatic and tectonic forcing are complex. Additionally, the dominance of one or the other varies in space and also over time, inheriting various traces of the paleo-morphodynamic conditions to the subsequent process regimes. To unravel the forces driving the evolution of relief in active mountains, numerous studies employ the drainage network of the corresponding mountains as a proxy of landscape evolution. Especially the rates of river incision provide a powerful tool to characterize the surface response and infer causes behind it. Several parameters of river incision are available to describe the fluvial incision at individual sites (e.g. terrace incision rates), along the river course (e.g. longitudinal river profiles, Hack index) and in its perpendicular dimension (e.g. valley cross sections, valley shape ratios). But they require careful interpretation. They are sensitive to both, climatic and tectonic forcing. Therefore, the synopsis of such indices for fluvial incision is essential to evaluate the role of climatic versus tectonic forcing. Here, we use the Panj river system, the major river draining the Pamir mountains of Central Asia, as an example. The Panj experiences high altitude changes of more than 4000

  12. Ultrafast Relaxation in Conjugated Polymers

    NASA Astrophysics Data System (ADS)

    Kobayashi, Takayoshi

    The following sections are included: * INTRODUCTION * EXPERIMENTAL * Samples * Femtosecond experimental apparatus * RESULTS AND DISCUSSION * Poly(phenylacetylenes) * Blue-phase PDA-3BCMU * Red-phase PDA-4BCMU * Blue-phase PDA-DFMP * P3MT * P3DT * PTV * RELAXATION MECHANISMS * Review of the previous works * Symmetry of the lower electronic excited states * Primary relaxation processes * Theoretical studies of nonlinear excitations * Mechanism of relaxation in polymers with a weakly nondegenerate ground state (poly(phenylacetylene)s) * Dual peak component with power-law decay * Single-peak component with an exponential decay * Hot self-trapped exciton * Transition to the electron-hole threshold * Transition to a biexciton state * Mechanism of relaxation in polymers with a strongly or moderately nondegenerate ground state * Classifications of polymers * Femtosecond relaxation * Picosecond relaxation * CONCLUSION * Acknowledgments * REFERENCES

  13. Relaxing music for anxiety control.

    PubMed

    Elliott, Dave; Polman, Remco; McGregor, Richard

    2011-01-01

    The purpose of this investigation was to determine the characteristics of relaxing music for anxiety control. Undergraduate students (N=84) were instructed to imagine themselves in an anxiety producing situation while listening to a selection of 30 music compositions. For each composition, level of relaxation, the factors that either enhanced or detracted from its relaxing potential and the emotional labels attached were assessed. Participants were also asked to state which music components (e.g., tempo, melody) were most conducive to relaxation. Additional information was obtained through the use of a focus group of 6 undergraduate music students. This paper presents details on the characteristics of relaxing-music for anxiety control and emotional labels attached to the relaxing compositions. Furthermore, an importance value has been attached to each of the music components under scrutiny, thus providing an indication of which music components should receive greatest attention when selecting music for anxiety control.

  14. ABC relaxation theory and the factor structure of relaxation states, recalled relaxation activities, dispositions, and motivations.

    PubMed

    Smith, J C; Wedell, A B; Kolotylo, C J; Lewis, J E; Byers, K Y; Segin, C M

    2000-06-01

    ABC Relaxation Theory proposes 15 psychological relaxation-related states (R-States): Sleepiness, Disengagement, Physical Relaxation, Mental Quiet, Rested/Refreshed, At Ease/At Peace, Energized, Aware, Joy, Thankfulness and Love, Prayerfulness, Childlike Innocence, Awe and Wonder, Mystery, and Timeless/Boundless/Infinite. The present study summarizes the results of 13 separate factor analyses of immediate relaxation-related states, states associated with recalled relaxation activities, relaxation dispositions, and relaxation motivations on a combined sample of 1,904 individuals (group average ages ranged from 28-40 yr.). Four exploratory factor analyses of Smith Relaxation Inventories yielded 15 items that most consistently and exclusively load (generally at least .70) on six replicated factors. These items included happy, joyful, energized, rested, at peace, warm, limp, silent, quiet, dozing, drowsy, prayerful, mystery, distant, and indifferent. Subsequent factor analyses restricted to these items and specifying six factors were performed on 13 different data sets. Each yielded the same six-factor solution: Factor 1: Centered Positive Affect, Factor 2: Sleepiness, Factor 3: Disengagement, Factor 4: Physical Relaxation, Factor 5: Mental Quiet, and Factor 6: Spiritual. Implications for ABC Relaxation Theory are discussed.

  15. Gamma Knife output factor measurements using VIP polymer gel dosimetry

    SciTech Connect

    Moutsatsos, A.; Petrokokkinos, L.; Karaiskos, P.; Papagiannis, P.; Georgiou, E.; Dardoufas, K.; Sandilos, P.; Torrens, M.; Pantelis, E.; Kantemiris, I.; Sakelliou, L.; Seimenis, I.

    2009-09-15

    Purpose: Water equivalent polymer gel dosimeters and magnetic resonance imaging were employed to measure the output factors of the two smallest treatment fields available in a Gamma Knife model C radiosurgery unit, those formed employing the 4 and 8 mm final collimator helmets. Methods: Three samples of the VIP normoxic gel formulation were prepared and irradiated so that a single shot of the field whose output factor is to be measured and a single shot of the reference 18 mm field were delivered in each one. Emphasis is given to the development and benchmarking of a refined data processing methodology of reduced uncertainty that fully exploits the 3D dose distributions registered in the dosimeters. Results: Polymer gel results for the output factor of the 8 mm collimator helmet are found to be in close agreement with the corresponding value recommended by the vendor (0.955{+-}0.007 versus 0.956, respectively). For the 4 mm collimator helmet, however, polymer gel results suggest an output factor 3% lower than the value recommended by the vendor (0.841{+-}0.009 versus 0.870, respectively). Conclusions: A comparison with corresponding measurements published in the literature indicates that output factor results of this work are in agreement with those obtained using dosimetric systems which, besides fine spatial resolution and lack of angular and dose rate dependence of the dosimeter's response, share with polymer gels the favorable characteristic of minimal radiation field perturbation.

  16. Measurement of Gamma Knife registered helmet factors using MOSFETs

    SciTech Connect

    Kurjewicz, Laryssa; Berndt, Anita

    2007-03-15

    The relative dose rate for the different Gamma Knife registered helmets (4, 8, 14, and 18 mm) is characterized by their respective helmet factors. Since the plateau of the dose profile for the 4 mm helmet is at most 1 mm wide, detector choices are limited. Traditionally helmet factors have been measured using 1x1x1 mm{sup 3} thermoluminescent dosimeters (TLDs). However, these are time-consuming, cumbersome measurements. This article investigates the use of metal-oxide-semiconductor field effect transistors (MOSFETs) (active area of 0.2x0.2 mm{sup 2}) as a more accurate and convenient dosimeter. Their suitability for these measurements was confirmed by basic characterization measurements. Helmet factors were measured using both MOSFETs and the established TLD approach. A custom MOSFET cassette was designed in analogy to the Elekta TLD cassette (Elekta Instruments AB) for use with the Elekta dosimetry sphere. Although both dosimeters provided values within 3% of the manufacturer's suggestion, MOSFETs provided superior accuracy and precision, in a fraction of the time required for the TLD measurements. Thus, MOSFETs proved to be a reasonable alternative to TLDs for performing helmet factor measurements.

  17. Gamma Knife Surgery for Metastatic Brain Tumors from Gynecologic Cancer.

    PubMed

    Matsunaga, Shigeo; Shuto, Takashi; Sato, Mitsuru

    2016-05-01

    The incidences of metastatic brain tumors from gynecologic cancer have increased. The results of Gamma Knife surgery (GKS) for the treatment of patients with brain metastases from gynecologic cancer (ovarian, endometrial, and uterine cervical cancers) were retrospectively analyzed to identify the efficacy and prognostic factors for local tumor control and survival. The medical records were retrospectively reviewed of 70 patients with 306 tumors who underwent GKS for brain metastases from gynecologic cancer between January 1995 and December 2013 in our institution. The primary cancers were ovarian in 33 patients with 147 tumors and uterine in 37 patients with 159 tumors. Median tumor volume was 0.3 cm(3). Median marginal prescription dose was 20 Gy. The local tumor control rates were 96.4% at 6 months and 89.9% at 1 year. There was no statistically significant difference between ovarian and uterine cancers. Higher prescription dose and smaller tumor volume were significantly correlated with local tumor control. Median overall survival time was 8 months. Primary ovarian cancer, controlled extracranial metastases, and solitary brain metastasis were significantly correlated with satisfactory overall survival. Median activities of daily living (ADL) preservation survival time was 8 months. Primary ovarian cancer, controlled extracranial metastases, and higher Karnofsky Performance Status score were significantly correlated with better ADL preservation. GKS is effective for control of tumor progression in patients with brain metastases from gynecologic cancer, and may provide neurologic benefits and preservation of the quality of life. Copyright © 2016 Elsevier Inc. All rights reserved.

  18. First year experience with newly developed Leksell Gamma Knife Perfexion.

    PubMed

    Bhatnagar, Jagdish P; Novotny, Josef; Niranjan, Ajay; Kondziolka, Douglas; Flickinger, John; Lunsford, Dade; Huq, M Saiful

    2009-07-01

    A new model of Leksell Gamma Knife(R) (LGK), known as Perfexion (LGK PFX), was introduced by Elekta Instrument, AB, Sweden, in 2006. This model has a radically different design from the earlier models U, B, C and 4C. Dosimetric characteristics of LGK PFX, technical differences between LGK PFX and LGK 4C, experience gained with acceptance testing and commissioning of the LGK PFX, and comparison between LGK PFX and LGK 4C are presented in this study. Excellent agreement is found between the manufacturers recommended values of absorbed dose rate, relative output factors for 4 and 8 mm collimators, coincidence of mechanical and dosimetric isocenter, FWHM for beam profiles for various collimators and those reported in the present study. Excellent agreement is also found between the dosimetric characteristics of LGK PFX and LGK 4C for the 4 and 8 mm collimators. Examples of clinical cases treated with LGK PFX and impact of LGK PFX on workflow and dosimetric conformity of treatment planning is also given. The set up and treatment of patients on the LGK PFX is much more efficient since it is a fully automated system. The system also provides more options to generate plan with high dosimetric conformity.

  19. Effect of dorsomedial hypothalamic nuclei knife cuts on ingestive behavior.

    PubMed

    Bellinger, L L; Bernardis, L L

    1999-06-01

    Previous findings show that rats with electrolytic or excitotoxic lesions in the dorsomedial hypothalamic nucleus (DMN) are hypophagic and hypodipsic and have reduced ponderal and linear growth but normal body composition. DMN-lesioned (DMNL) rats also show altered ingestive responses to naloxone. The present study investigated the intrahypothalamic nerve pathways involved in these DMNL effects and the response of the pathways to deprivation challenges by placing knife cuts posterior (Post), lateral (Lat), ventral (Vent), dorsal, or anterior to the DMN or by administering sham operations. One major finding was that rats with Post or Vent were hypophagic (P < 0. 05) and had reduced body weight but responded normally to deprivation challenges. Post and Lat groups were hypodipsic (P < 0. 05), but plasma Na+, K+, and osmolality and 24-h post-water-deprivation drinking responses were similar in all groups. Naloxone did not suppress the intake of Post rats. It appears that the hypophagia and the reduced body weight after DMNL involve fibers entering or leaving the DMN from ventral and posterior directions, and they may be part of an opioid feeding system.

  20. Pulsed electron avalanche knife: new technology for cataract surgery

    PubMed Central

    Priglinger, Siegfried G; Palanker, Daniel; Alge, Claudia S; Kreutzer, Thomas C; Haritoglou, Christos; Grueterich, Martin; Kampik, Anselm

    2007-01-01

    Background The pulsed electron avalanche knife (PEAK‐fc) is a new pulsed electrosurgical device that allows for precise, “cold” and traction‐free tissue dissection. Aim To evaluate the surgical applicability, safety and potential complications of PEAK‐fc in complicated cataract surgery. Methods The study included five children with congenital cataracts, two patients with advanced senile cataracts, six adults with mature cataracts, three of them with posterior iris synechia, three patients with post‐traumatic cataracts with zonulolysis, one patient with intumescent traumatic cataract and three patients with massive anterior capsule opacification. Anterior and posterior capsulotomies, iris synechiolysis, dissection of anterior capsule opacification and fibrotic scar tissue were performed. PEAK‐fc was set at voltages of 500–700 V, pulse duration of 0.1 m and repetition rate of 40–100 Hz. Results Anterior and posterior capsulotomies were successfully and safely performed in all eyes. The edges of capsulotomies appeared sharp, showing only limited collateral damage. PEAK‐fc worked best by just gently touching the capsule, thereby avoiding tractional forces or pressure on the lens capsule. Posterior iris synechiae could be released and anterior capsule opacification was dissected without complications. Conclusions PEAK‐fc is a very helpful cutting device for complicated cases of cataract surgery, especially for mature and congenital cataracts, traumatic zonulolysis or anterior segment complications after intraocular inflammation. PMID:17229798

  1. Analytical description of dose profile behaviour in Gamma Knife radiosurgery

    NASA Astrophysics Data System (ADS)

    Fenner, J.; Gwilliam, M.; Mehrem, R.; Bird, A.; Walton, L.

    2008-04-01

    Stereotactic Gamma Knife radiosurgery utilizes ionizing beams from 60Co sources and relies on a combination of collimator sizes, weighting, etc to generate a high-dose region that is conformal with a designated target volume. Dose computation is typically performed by computer, but in this paper, single collimator dose profile behaviour is modelled analytically and then extended to accommodate multiple collimators of different weights with co-located isocentres. The dose profile from a single helmet is derived from a top-hat beam profile approximation and an idealized symmetric distribution of sources is used to represent the 201 sources within a collimating helmet. The results from the analysis are validated by an independent numerical model and also compared with those obtained by other groups using numerical and experimental methods. With respect to multiple collimators, the relationship between the size (full width half maximum) of the irradiated volume and relative collimator weighting is also examined using the simple analytical model. The simplicity of the mathematics clarifies the relationship between beam profile, dose profile and multiple collimator behaviour, and provides data that compare favourably with published literature.

  2. Penetrating and Intrastromal Corneal Arcuate Incisions in Rabbit and Human Cadaver Eyes: Manual Diamond Blade and Femtosecond Laser-Created Incisions.

    PubMed

    Gray, Brad; Binder, Perry S; Huang, Ling C; Hill, Jim; Salvador-Silva, Mercedes; Gwon, Arlene

    2016-07-01

    To compare morphologic differences between freehand diamond or femtosecond laser-assisted penetrating and intrastromal arcuate incisions. Freehand diamond blade, corneal arcuate incisions (180° apart, 60° arc lengths) and 150 kHz femtosecond laser (80% scheimpflug pachymetry depth corneal thickness) arcuate incisions were performed in rabbits. Intrastromal arcuate incisions (100 μm above Descemet's membrane, 100 μm below epithelium) were performed in rabbit corneas (energy 1.2 μJ, spot line separation 3 × 3 μm, 90° side cut angle). Eyes were examined by slit lamp and light microscopy up to 47 days post-procedure. Freehand diamond blade penetrating incisions, and femtosecond laser penetrating and intrastromal arcuate incisions (energy 1.8 μJ, spot line separation 2 × 2 μm) were performed in cadaver eyes. Optical coherence tomography was performed immediately after surgery and the corneas were fixed for light scanning and transmission electron microscopy. The rabbit model showed anterior stromal inflammation with epithelial hyperplasia in penetrating blade and laser penetrating wounds. The laser intrastromal and penetrating incisions showed localized constriction of the stromal layers of the cornea near the wound. In cadaver eyes, penetrating wound morphology was similar between blade and laser whereas intrastromal wounds did not affect the cornea above or below incisions. Penetrating femtosecond laser arcuate incisions have more predictable and controlled outcomes shown by less post-operative scarring than incisions performed with a diamond blade. Intrastromal incisions do not affect uncut corneal layers as demonstrated by histopathology. The femtosecond laser has significant advantages in its ability to make intrastromal incisions which are not achievable by traditional freehand or mechanical diamond blades.

  3. Development of a Stereotactic Device for Gamma Knife Irradiation of Small Animals

    PubMed Central

    Chung, Hyun-Tai; Kim, Dong Gyu; Paek, Sun Ha; Cho, Keun-Tae

    2008-01-01

    Objective The authors developed a stereotactic device for irradiation of small animals with Leksell Gamma Knife® Model C. Development and verification procedures were described in this article. Methods The device was designed to satisfy three requirements. The mechanical accuracy in positioning was to be managed within 0.5 mm. The strength of the device and structure were to be compromised to provide enough strength to hold a small animal during irradiation and to interfere the gamma ray beam as little as possible. The device was to be used in combination with the Leksell G-frame® and KOPF® rat adaptor. The irradiation point was determined by separate imaging sequences such as plain X-ray images. Results The absolute dose rate with the device in a Leksell Gamma Knife was 3.7% less than the value calculated from Leksell Gamma Plan®. The dose distributions measured with GAFCHROMIC® MD-55 film corresponded to those of Leksell Gamma Plan® within acceptable range. The device was used in a series of rat experiments with a 4 mm helmet of Leksell Gamma Knife. Conclusion A stereotactic device for irradiation of small animals with Leksell Gamma Knife Model C has been developed so that it fulfilled above requirements. Absorbed dose and dose distribution at the center of a Gamma Knife helmet are in acceptable ranges. The device provides enough accuracy for stereotactic irradiation with acceptable practicality. PMID:19096541

  4. The current role of Gamma Knife radiosurgery in the management of intracranial haemangiopericytoma.

    PubMed

    Spina, Alfio; Boari, Nicola; Gagliardi, Filippo; Donofrio, Carmine A; Franzin, Alberto; Mortini, Pietro

    2016-04-01

    Haemangiopericytomas (HPCs) are rare tumours characterised by aggressive behaviour with tendency to local recurrence and to metastasise. WHO grade II and grade III tumours show different progression-free survival and overall survival rates. Gross total tumour resection is still considered the treatment of choice. Adjuvant radiation therapies represent an option in the treatment strategy regardless the extent of resection. Based on this consideration, Gamma Knife radiosurgery has been introduced either as a primary treatment or as an adjuvant treatment for residual or recurrent tumours. A systematic search was performed on PubMed, Web of Science and Google Scholar for clinical series reporting Gamma Knife radiosurgery, Cyberknife and Linear Accelerator (LINAC) for the management of intracranial HPCs. Fourteen studies focusing on the effects of Gamma Knife radiosurgery for intracranial HPCs were included. Four studies reported data on Cyberknife radiosurgery and LINAC. A total of 208 patients harbouring 366 tumours have been reported. Patient's features, radiosurgical treatment characteristics and follow-up data of the pertinent literature have been critically revised. Gamma Knife radiosurgery and the other radiosurgical techniques represent a feasible and effective therapy in the management of HPCs. Tumour control and survival rate are comparable to those reported for radiotherapy. Further studies should be focused to define the exact role of Gamma Knife radiosurgery in the management of HPCs.

  5. Constant face pain in typical trigeminal neuralgia and response to γ knife radiosurgery.

    PubMed

    Brisman, Ronald

    2013-01-01

    Constant pain, especially if prominent, is sometimes considered incompatible with a diagnosis of typical idiopathic trigeminal neuralgia. This study aims to clarify the frequency of patient-reported constant pain in patients with medically intractable, typical, idiopathic trigeminal neuralgia as diagnosed with standard clinical parameters and confirmed by the response to a modified McGill questionnaire, a 'hold-still' test that eliminated triggers and the response to Gamma Knife radiosurgery. Forty consecutive patients with typical trigeminal neuralgia were given questionnaires prior to Gamma Knife radiosurgery. Those with constant pain were further tested by being advised to hold completely still for up to 3 min. Final pain relief was evaluated after Gamma Knife radiosurgery. Twenty of forty patients indicated on a questionnaire that they had constant face pain. Pain decreased on the 'hold-still' test on all 12 patients who were tested. Following Gamma Knife radiosurgery, there was no significant difference in pain relief in those without or with constant pain. Patients with typical idiopathic trigeminal neuralgia frequently report that 50% or more of their pain is constant. This constant pain is markedly decreased if the patient holds completely still for a few minutes and does not affect the outcome of Gamma Knife radiosurgery. Copyright © 2013 S. Karger AG, Basel.

  6. Inflammatory cytokine expression following the use of bipolar electrocoagulation, ultracision harmonic scalpel and cold knife biopsy.

    PubMed

    Litta, Pietro; Saccardi, Carlo; Gizzo, Salvatore; Conte, Lorena; Ambrosi, Giulia; Sissi, Claudia; Palumbo, Manlio

    2015-08-01

    Electrical surgical devices may determine tissue damage through lateral thermal spread and activation of inflammatory processes. Several tissue effects are associated with the use of different surgical instruments. The aim of the present study was to compare tissue damage following the application of cold knife biopsy, bipolar electrocoagulation and the ultracision harmonic scalpel, through the analysis of inflammatory gene mediator expression. Three fragments of the round ligament (length 0.5 cm) were obtained from 22 females who had undergone total or subtotal laparoscopic hysterectomy using three different modes of resection: Cold knife biopsy, bipolar electrocoagulation and ultracision harmonic scalpel. The tissue fragments were examined by quantitative polymerase chain reaction (qPCR) analysis of selected cytokines. Gene expression analysis demonstrated large standard deviations due to individual variability among patients and indicated variability in the concentrations of cytokines in the three different samples. The quantity of cytokine mRNA in the cold knife biopsy samples was generally greater than those obtained by other techniques. Tumor necrosis factor-α expression was significantly higher in the sample obtained with the ultracision harmonic scalpel and bipolar electrocoagulation (P=0.033) when compared with cold knife biopsy. The inflammatory response was analyzed by the quantification of gene expression through the use of qPCR. The ultracision harmonic scalpel and bipolar electrocoagulation triggered the inflammatory cascade and resulted in an increased production of cytokines compared with cold knife biopsy.

  7. Management of Liver Cancer Argon-helium Knife Therapy with Functional Computer Tomography Perfusion Imaging.

    PubMed

    Wang, Hongbo; Shu, Shengjie; Li, Jinping; Jiang, Huijie

    2016-02-01

    The objective of this study was to observe the change in blood perfusion of liver cancer following argon-helium knife treatment with functional computer tomography perfusion imaging. Twenty-seven patients with primary liver cancer treated with argon-helium knife and were included in this study. Plain computer tomography (CT) and computer tomography perfusion (CTP) imaging were conducted in all patients before and after treatment. Perfusion parameters including blood flows, blood volume, hepatic artery perfusion fraction, hepatic artery perfusion, and hepatic portal venous perfusion were used for evaluating therapeutic effect. All parameters in liver cancer were significantly decreased after argon-helium knife treatment (p < 0.05 to all). Significant decrease in hepatic artery perfusion was also observed in pericancerous liver tissue, but other parameters kept constant. CT perfusion imaging is able to detect decrease in blood perfusion of liver cancer post-argon-helium knife therapy. Therefore, CTP imaging would play an important role for liver cancer management followed argon-helium knife therapy.

  8. Dose verification of single shot gamma knife applications using VIPAR polymer gel and MRI

    NASA Astrophysics Data System (ADS)

    Karaiskos, P.; Petrokokkinos, L.; Tatsis, E.; Angelopoulos, A.; Baras, P.; Kozicki, M.; Papagiannis, P.; Rosiak, J. M.; Sakelliou, L.; Sandilos, P.; Vlachos, L.

    2005-03-01

    This work describes an experimental procedure with potential to assess the overall accuracy associated with gamma knife clinical applications, from patient imaging and dosimetry planning to patient positioning and dose delivery using the automated positioning system of a Leksell Gamma Knife model C. The VIPAR polymer gel-MRI dosimetry method is employed due to its inherent three-dimensional feature and linear dose response over the range of gamma knife applications. Different polymer gel vials were irradiated with single shot gamma knife treatment plans using each of the four available collimator helmets to deliver a maximum dose of 30 Gy. Percentage relative dose results are presented not only in the form of one-dimensional profiles but also planar isocontours and isosurfaces in three dimensions. Experimental results are compared with corresponding Gammaplan treatment planning system calculations as well as acceptance test radiochromic film measurements. A good agreement, within the experimental uncertainty, is observed between measured and expected dose distributions. This experimental uncertainty is of the order of one imaging pixel in the MRI gel readout session (<1 mm) and allows for the verification of single shot gamma knife applications in terms of acceptance specifications for precision in beam alignment and accuracy. Averaging net R2 results in the dose plateau of the 4 mm and 18 mm collimator irradiated gel vials, which were MR scanned in the same session, provides a crude estimate of the 4 mm output factor which agrees within errors with the default value of 0.870.

  9. Medial epicanthoplasty using the palpebral margin incision method.

    PubMed

    Chen, Wen; Li, Shenkai; Li, Yangqun; Wang, Yining

    2009-12-01

    Epicanthal deformity is one of the most frequently encountered cosmetic problems in Asian people. Herein, we introduce a new method for correction of epicanthal folds, which always is performed in combination with double eyelidplasty. First, through upper and lower palpebral margin incisions, we release and excise the connective and orbicularis oculi muscle dense fibres underlying the epicanthal folds, as well as the superficial head of the medial canthal ligament. After repositioning the medial canthus in a double eyelidplastic procedure, we cut off the redundant skin tissue and close the incisions. 82 epicanthoplasties have been performed during the past 2 years. Follow-up time ranged from 1 to 32 months. Postsurgery scars were invisible in all cases. All patients were satisfied with the results. No recurrence of the epicanthal fold was observed. The new method introduced has advantages in avoiding scar formation and is an especially suitable approach for epicanthoplasty in Asian patients.

  10. Comparison of immediate small-incision lenticule extraction after suction loss with uneventful small-incision lenticule extraction.

    PubMed

    Park, Jin Hyoung; Koo, Hyung Jin

    2017-04-01

    To evaluate and compare the predictability and safety of immediate small-incision lenticule extraction, also known as SMILE, after suction loss during the procedure with those of uneventful small-incision lenticule extraction. Nunemiso Eye Center, Seoul, South Korea. Retrospective case series. Patients who had immediate small-incision lenticule extraction using reapplied suction (study group) or uneventful small-incision lenticule extraction (control group) for myopia or myopic astigmatism were included. All patients were followed for at least 12 months. Demographic as well as visual and refractive outcomes were compared between the 2 groups. Twenty-three eyes were enrolled in the study group and 48 eyes in the control group. The overall cumulative incidence of suction loss was 0.2% (28 of 11 762 eyes). Twenty-two eyes (96%) in the study group had unchanged or improved decimal Snellen corrected distance visual acuity (CDVA). At 12 months, the mean uncorrected distance visual acuity, CDVA, and manifest refraction defocus equivalent in the study group and control group were 0.99 ± 0.17 (SD), 1.11 ± 0.14, 0.75 ± 0.50 diopters (D), and 1.25 ± 0.22 D, 1.26 ± 0.21 D, 0.35 ± 0.26 D, respectively (P = .000, P = .007, and P = .000, respectively). The correlation between the achieved and the attempted spherical equivalent refraction was slightly better in the control group (R(2) = 0.972) than in the study group (R(2) = 0.933). Immediate small-incision lenticule extraction using reapplied suction resulted in safe and clinically predictable long-term outcomes. However, predictability was lower for immediate than for uneventful small-incision lenticule extraction. Copyright © 2017 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  11. Relaxation Techniques for Trauma.

    PubMed

    Scotland-Coogan, Diane; Davis, Erin

    2016-01-01

    Physiological symptoms of posttraumatic stress disorder (PTSD) manifest as increased arousal and reactivity seen as anger outburst, irritability, reckless behavior with no concern for consequences, hypervigilance, sleep disturbance, and problems with focus (American Psychiatric Association, 2013 ). In seeking the most beneficial treatment for PTSD, consideration must be given to the anxiety response. Relaxation techniques are shown to help address the physiological manifestations of prolonged stress. The techniques addressed by the authors in this article include mindfulness, deep breathing, yoga, and meditation. By utilizing these techniques traditional therapies can be complemented. In addition, those who are averse to the traditional evidence-based practices or for those who have tried traditional therapies without success; these alternative interventions may assist in lessening physiological manifestations of PTSD. Future research studies assessing the benefits of these treatment modalities are warranted to provide empirical evidence to support the efficacy of these treatments.

  12. Hydraulic Implications of Different Megaflood Canyon Incision Models

    NASA Astrophysics Data System (ADS)

    Larsen, I. J.; Lamb, M. P.

    2015-12-01

    Deeply incised canyons are some of the most dramatic features of landscapes carved by megafloods. The geometry of these canyons may reveal information regarding flood magnitudes during the last ice age on Earth and the volume of water flowing on early Mars. Canyons on both planets have been alternatively modeled as 'channels', where the modern topography was completely inundated with water to the elevation of the canyon rims, or as 'valleys' that were progressively incised by lesser discharges. Here we combine numerical flood simulations and sediment transport mechanics to explore the hydraulic implications that result from modeling the canyons as 'channels' versus 'valleys'. Over 300 floods were simulated for Moses Coulee, a 60 km-long canyon in the Channeled Scablands of eastern Washington, USA, using a 2D, depth-averaged hydraulic model. We simulated floods with discharges ranging from 0.1 million m3 s-1 to 6 million m3 s-1 using both the modern landscape as a topographic boundary condition and synthetic topographies that restored the canyon floor to different elevations as guided by strath terraces. For each simulation we tracked whether shear stresses on the terrace treads exceeded thresholds for sliding of basalt columns. Simulations using the modern topography indicate shear stresses were sufficiently high to erode the terraces at discharges lower than bankfull, and surprisingly, shear stresses decrease with increasing discharge at some sites due to backwater dynamics, which constrains canyon formation to moderate discharges. Simulations performed on the synthetic topography suggest the canyon could have been incised progressively by floods smaller than those required to fill the canyon to bankfull stage. These results suggest the canyons can be viewed as valleys that incised progressively, as opposed to channels filled with water, which has implications for placing bounds on paleoflood hydraulic reconstruction on Earth and Mars.

  13. Single-Incision Laparoscopic Colon and Rectal Surgery

    PubMed Central

    Keller, Deborah S.; Haas, Eric M.

    2015-01-01

    Single-incision laparoscopic surgery (SILS) was introduced to further the enhanced outcomes of multiport laparoscopy. Multiple studies have demonstrated the safety and feasibility of SILS for both benign and malignant colorectal disease. SILS provides the potential for improved cosmesis, postoperative outcomes, and patient quality of life. However, widespread use has been limited by technical demands and lack of an evidence and competency-based curriculum. PMID:26491404

  14. Single-incision laparoscopic cholecystectomy: How I do it?

    PubMed Central

    Bhandarkar, Deepraj; Mittal, Gaurav; Shah, Rasik; Katara, Avinash; Udwadia, Tehemton E

    2011-01-01

    Single-incision laparoscopic cholecystectomy (SILC) is a relatively new technique that is being increasingly used by surgeons around the world. Unlike the multi-port cholecystectomy, a standardised technique and detailed description of the operative steps of SILC is lacking in the literature. This article provides a stepwise account of the technique of SILC aimed at surgeons wishing to learn the procedure. A brief review of the current literature on SILC follows. PMID:21197237

  15. Comet Bursting Through Relaxation

    NASA Astrophysics Data System (ADS)

    Jacobson, Seth A.; Scheeres, D. J.

    2012-10-01

    Comets may be excited and occupy non-principal axis (complex) rotation states for a large fraction of their lifetimes. Many comet nuclei have been identified or are suspected to occupy non-principal axis (complex) rotation [Belton 2005, etc.] as well as have evolving rotation rates [Belton 2011, etc.]. Comet orbits drive these rotation states through cycles of excitation due to surface jets and relaxation due to time variable internal stresses that dissipate energy in the anelastic comet interior. Furthermore, relaxation from complex rotation can increase the loads along the symmetry axis of prolate comets. These loads stretch the body along the symmetry axis and may be the cause of the characteristic ``bowling pin’’ shape and eventually may lead to failure. This is an alternative model for comet bursting. Each cycle deposits only a small amount of energy and stress along the axis, but this process is repeated every orbit during which jets are activated. Our model for the evolution of comet nuclei includes torques due to a number of discrete jets located on the surface based on Neishtadt et al. [2002]. The model also includes internal dissipation using an approach developed by Sharma et al. [2005] and Vokrouhlicky et al. [2009]. These equations are averaged over the instantaneous spin state and the heliocentric orbit so the long-term evolution of the comet can be determined. We determine that even after the inclusion of internal dissipation there still exist non-principal axis equilibrium states for certain jet geometries. For ranges of dissipation factors and jet geometries, prolate comets are found to occupy states that have time variable internal loads over long time periods. These periodic loadings along the symmetry axis may lead to ``necking’’ as the body extends along the axis to release the stress and eventually disruption.

  16. Bedrock incision by bedload: insights from direct numerical simulations

    NASA Astrophysics Data System (ADS)

    Aubert, Guilhem; Langlois, Vincent J.; Allemand, Pascal

    2016-04-01

    Bedload sediment transport is one of the main processes that contribute to bedrock incision in a river and is therefore one of the key control parameters in the evolution of mountainous landscapes. In recent years, many studies have addressed this issue through experimental setups, direct measurements in the field, or various analytical models. In this article, we present a new direct numerical approach: using the classical methods of discrete-element simulations applied to granular materials, we explicitly compute the trajectories of a number of pebbles entrained by a turbulent water stream over a rough solid surface. This method allows us to extract quantitatively the amount of energy that successive impacts of pebbles deliver to the bedrock, as a function of both the amount of sediment available and the Shields number. We show that we reproduce qualitatively the behaviour observed experimentally by Sklar and Dietrich (2001) and observe both a "tool effect" and a "cover effect". Converting the energy delivered to the bedrock into an average long-term incision rate of the river leads to predictions consistent with observations in the field. Finally, we reformulate the dependency of this incision rate with Shields number and sediment flux, and predict that the cover term should decay linearly at low sediment supply and exponentially at high sediment supply.

  17. Open reduction of nasal bone fractures through an intercartilaginous incision.

    PubMed

    Kim, Ji Heui; Lee, Jun Ho; Hong, Seok Min; Park, Chan Hum

    2013-01-01

    Open reduction through an intercartilaginous incision was useful for treating delayed-diagnosed nasal bone fractures because it resulted in a successful outcome with minimal complications. Nasal bone fractures are generally managed with closed reduction, which is usually inadequate and results in airway obstruction with a delayed diagnosis of nasal bone fracture when bone healing and fibrotic adhesions around the bone fragment have progressed. This study investigated the surgical outcome of open reduction through an intercartilaginous incision for delayed-diagnosis nasal bone fractures. The study enrolled 18 patients who underwent open reduction through an intercartilaginous incision to correct delayed-diagnosis nasal bone fractures. Three independent otorhinolaryngologists evaluated the outcomes 4-35 months (average 12.7 months) postoperatively as excellent, fair or poor. The time from injury to surgery was 11-39 days (20-39 days in adults and 11-30 days in children). The 18 cases included 16 primary repairs and two revisions. A Kirschner wire was inserted in six (33.3%) patients who had unstable reduced nasal bones. Postoperatively, l5 (83%) patients had excellent results, two (11%) had fair, and one (6%) had a poor outcome. No patient experienced any complication.

  18. Small-incision lenticule extraction in posterior polymorphic corneal dystrophy.

    PubMed

    Park, Jin Hyoung; Lee, Jae Hyun; Koo, Hyung Jin

    2016-05-01

    We present the case of a 37-year-old man with posterior polymorphic corneal dystrophy who had small-incision lenticule extraction surgery to correct myopic refractive errors. The subjective refraction was -2.62 in the right eye and -2.50 -0.25 × 80 in the left eye. Slitlamp biomicroscopy revealed a band-like lesion in the corneal endothelium of the right eye. The endothelial cell count was 1745 cells/mm(2) in the right eye and 2945 cells/mm(2) in the left eye. Small-incision lenticule extraction was performed to correct the myopic refractive errors in both eyes. Twelve months after surgery, the uncorrected distance visual acuity in both eyes was 20/20 and the posterior polymorphic corneal dystrophy lesion had not progressed. The case suggests that small-incision lenticule extraction surgery can be performed successfully and safely in patients with posterior polymorphic corneal dystrophy. None of the authors has a financial or proprietary interest in any material or method mentioned. Copyright © 2016 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

  19. Progressive incision of the Channeled Scablands by outburst floods.

    PubMed

    Larsen, Isaac J; Lamb, Michael P

    2016-10-13

    The surfaces of Earth and Mars contain large bedrock canyons that were carved by catastrophic outburst floods. Reconstructing the magnitude of these canyon-forming floods is essential for understanding the ways in which floods modify planetary surfaces, the hydrology of early Mars and abrupt changes in climate. Flood discharges are often estimated by assuming that the floods filled the canyons to their brims with water; however, an alternative hypothesis is that canyon morphology adjusts during incision such that bed shear stresses exceed the threshold for erosion by a small amount. Here we show that accounting for erosion thresholds during canyon incision results in near-constant discharges that are five- to ten-fold smaller than full-to-the-brim estimates for Moses Coulee, a canyon in the Channeled Scablands, which was carved during the Pleistocene by the catastrophic Missoula floods in eastern Washington, USA. The predicted discharges are consistent with flow-depth indicators from gravel bars within the canyon. In contrast, under the assumption that floods filled canyons to their brims, a large and monotonic increase in flood discharge is predicted as the canyon was progressively incised, which is at odds with the discharges expected for floods originating from glacial lake outbursts. These findings suggest that flood-carved landscapes in fractured rock might evolve to a threshold state for bedrock erosion, thus implying much lower flood discharges than previously thought.

  20. Postmortem sole incisions - a new sign of heroin overdose?

    PubMed

    Benomran, Fawzi

    2008-01-01

    Postmortem sole incisions have been observed in a number of heroin overdose fatalities. Acqueintance of those victims confessed to producing those incisions as a life saving procedure in a futile attempt to help the comatose overdose victim. They thought that bleeding the unconscious victim would remove the overdose, in manner similar to bloodletting or phlebotomy which is still popular in the Gulf region. The presence of such wounds has become a first indication or rather "sign" of heroin poisoning. In such cases, laboratory investigation confirmed the pathologist's preliminary suspicion. In Dubai, postmortem sole incisions are important sign of death from heroin overdose even in the absence of other classical signs. This sign becomes more credible when accompanied by other signs and/or circumstantial evidence suggestive of heroin use. It is suggested that this should be called "bloodletting sign" of death from heroin overdose. The sign should not be confused with the self-inflicted cuts seen on the arms and forearms of drug misusers which are caused for other reasons.

  1. Single incision thoracoscopic sympathectomy for palmar and axillary hyperhidrosis

    PubMed Central

    2014-01-01

    Background: Primary hyperhidrosis is characterized by excessive sweating beyond physiological needs. It is a common disease (incidence 2.8%) that causes intense discomfort for patients. In the last decade, advantages of Single-Incision Thoracoscopic Sympathectomy have become clear, particularly in decreasing morbidity of sympathectomy. Patients and methods: From January 2010 to December 2012, 39 patients (29 females and 10 males) with primary palmar or axillary hyperhidrosis were treated by thoracoscopic sympathectomy. The age ranged from 18 to 40 years with a mean of 26.28 years. We used single incision thoracoscopic electrocoagulation through 10 mm incision for thoracic sympathetic chain (T2–T4). Results: The mean follow-up was 23.6 ± 14.2 months (range = 4–24 months). A total of 97.42% of patients were satisfied with the results. A total of 72.5% of patients had cure, one patient (2.5%) and another patient (2.5%) presented with recurrent axillary hyperhidrosis. The morbidity was 10.2% with no mortality. Percentage of compensatory sweating and gustatory sweating were 5.1% (p = .353) and 2.5% (p = .552), respectively. The result of sympathectomy in patients with both palmar and axillary hyperhidrosis was significantly better (17, 43.58%) compared to palmar type (14, 35.89%) or axillary type (7, 17.94%). Conclusion: Thoracoscopic sympathectomy is a simple, safe, and cost-effective therapy with good results and low complications. PMID:26770711

  2. A two-incision approach: promises and pitfalls.

    PubMed

    Rosenberg, Aaron G

    2005-09-01

    Is this an optimal procedure? Clearly, it is not for every patient, but it does serve patients who can benefit from rapid recovery as well as those patients truly interested in minimizing their down time. It also is clearly not for the occasional total hip surgeon. It is a technique that brings to the patient the maximum potential for speed of recovery. However, it is important to stress again that the surgical approach is just one factor facilitating the recovery curve. While the benefits are real, their importance must be weighed by both surgeon and patient relative to the risks. The risks are not insignificant, but generally decrease with time and experience. As opposed to several smaller incision modifications of routine approaches to THA, the two-incision approach does require a separate and distinctively different skill set, including alternative methods to make up for the lack of standard visualization and careful attention to details such as incision placement and location of the starting point in the intramedullary canal. However, in the rest of the medical world, that is what minimally invasive surgery is about.

  3. Pleistocene drainage incision in the upper Mississippi Valley Driftless Area

    SciTech Connect

    Knox, J.C.

    1985-01-01

    The deep dissection of the Wisconsin Driftless Area and topographically similar, but glaciated areas in adjacent states is generally acknowledged to have occurred during the Pleistocene, but the precise chronology has been poorly understood. The distribution of pre-Illinoian glacial outwash gravels on uplands and valley side benches near the Mississippi River, on the western margin of the Wisconsin Driftless Area, indicates that the major incision (50-60 m) of drainage had occurred during the very early Pleistocene. Deposits in cut-off valley meanders, a common feature in the lower reaches of Driftless Area rivers, provide a basis for relative dating of the valley incision. The cut-offs appear to have evolved episodically when, at various times during the Pleistocene, glacial debris blocked the drainages of the Mississippi and Wisconsin Rivers causing massive alluviation of side valley tributaries. A radiocarbon date of 21,910 +/- 350 year B.P., representing a buried soil horizon at 22 m depth and about 9 m above the bedrock floor of a cut-off valley meander and 18 m above the bedrock floor of the adjacent present-day valley, supports stratigraphic interpretations that suggest modest valley incision into bedrock probably occurred during the Illinoian and may have also occurred during the early Wisconsinan.

  4. Progressive incision of the Channeled Scablands by outburst floods

    NASA Astrophysics Data System (ADS)

    Larsen, Isaac J.; Lamb, Michael P.

    2016-10-01

    The surfaces of Earth and Mars contain large bedrock canyons that were carved by catastrophic outburst floods. Reconstructing the magnitude of these canyon-forming floods is essential for understanding the ways in which floods modify planetary surfaces, the hydrology of early Mars and abrupt changes in climate. Flood discharges are often estimated by assuming that the floods filled the canyons to their brims with water; however, an alternative hypothesis is that canyon morphology adjusts during incision such that bed shear stresses exceed the threshold for erosion by a small amount. Here we show that accounting for erosion thresholds during canyon incision results in near-constant discharges that are five- to ten-fold smaller than full-to-the-brim estimates for Moses Coulee, a canyon in the Channeled Scablands, which was carved during the Pleistocene by the catastrophic Missoula floods in eastern Washington, USA. The predicted discharges are consistent with flow-depth indicators from gravel bars within the canyon. In contrast, under the assumption that floods filled canyons to their brims, a large and monotonic increase in flood discharge is predicted as the canyon was progressively incised, which is at odds with the discharges expected for floods originating from glacial lake outbursts. These findings suggest that flood-carved landscapes in fractured rock might evolve to a threshold state for bedrock erosion, thus implying much lower flood discharges than previously thought.

  5. Post-Oligocene river incision, southern Sierra Madre Occidental, Mexico

    NASA Astrophysics Data System (ADS)

    Montgomery, David R.; López-Blanco, Jorge

    2003-09-01

    The Sierra Madre Occidental of western Mexico consists of a granitic basement covered by Oligocene ignimbrites that define a reference surface from which to estimate late Cenozoic river incision. A 90-m-grid digital elevation model was used to characterize contemporary topography and interpolate the Late Oligocene surface of the ignimbrite plateau from a surface fit to the highest points in the relatively undissected uplands between major river valleys. Long-term river incision rates calculated from the difference between this reference surface and longitudinal profiles of 11 rivers that flow toward the Tepic-Zacoalco rift zone range from about 0.01 to 0.2 mm year -1. River profiles of this region also show evidence of river capture driven by flexural uplift along the flank of the rift zone. River profile concavity values ( θ) in the Sierra Madre Occidental range from 0.22 to 0.63, a range similar to that reported previously for a wide range of environments. In contrast, the empirically constrained ratio of exponents in the stream power model of river incision ( m/ n) ranges from 0.44 to 0.52, close to the expected theoretical value of 0.5. The wider range of observed θ values may illustrate how θ can differ from the driving values of m/ n in non-steady-state bedrock river systems.

  6. Single incision laparoscopic surgery in general surgery: a review.

    PubMed

    Greaves, N; Nicholson, J

    2011-09-01

    Single incision laparoscopic surgery (SILS) is a rapidly developing field that may represent the future of laparoscopic surgery. The major advantage of SILS over standard laparoscopic surgery is in cosmesis, with surgery becoming essentially scarless if the incision is hidden within the umbilicus. Only one incision is required so the risk of potential complications like port site hernias, haematomas and wound infection is reduced. The trade-off for this is a technically more challenging procedure with different underlying principles to that of traditional laparoscopic surgery. A wide variety of new equipment has been developed to support SILS and the range of procedures that are amenable to the technique is increasing. To date most of the published data relating to SILS are in the form of case series, with the first large randomised controlled trials due to be completed by the end of 2012. The existing evidence suggests that SILS is similar to standard laparoscopic surgery in terms of complication rates, completion rates and post-operative pain scores. However, the duration of SILS is longer than equivalent laparoscopic procedures. This article discusses SILS with regard to its applications in general surgery and reviews the evidence currently available.

  7. Curative effect and costs of surgical and gamma knife treatments on intractable epilepsy caused by temporal-hippocampal sclerosis.

    PubMed

    Han, Z T; Chen, Q X

    2015-07-31

    This study aimed to investigate the curative effect and costs of surgical and gamma knife treatments on intractable epilepsy caused by temporal-hippocampal sclerosis. The subjects comprised patients who suffered from intractable epilepsy caused by temporal-hippocampal sclerosis and received treatment in the Department of Neurosurgery of our hospital between 2010 and 2011. After obtaining their consent, patients were evaluated and selected to receive surgical or gamma knife treatments. In the surgical group, the short-term curative rate was 92.60% and the average cost was US$ 1311.50 while in the gamma knife group, the short-term curative rate was 53.79%, and the average cost was US$ 2786.90. Both surgical and gamma knife treatments of intractable epilepsy caused by temporal-hippocampal sclerosis are safe and effective, but the short-term curative effect of surgical treatment is better than that of gamma knife, and its cost is lower.

  8. Influence of the substrate material on the knife-edge based profiling of tightly focused light beams.

    PubMed

    Huber, C; Orlov, S; Banzer, P; Leuchs, G

    2016-04-18

    The performance of the knife-edge method as a beam profiling technique for tightly focused light beams depends on several parameters, such as the material and height of the knife-pad as well as the polarization and wavelength of the focused light beam under study. Here we demonstrate that the choice of the substrate the knife-pads are fabricated on has a crucial influence on the reconstructed beam projections as well. We employ an analytical model for the interaction of the knife-pad with the beam and report good agreement between our numerical and experimental results. Moreover, we simplify the analytical model and demonstrate, in which way the underlying physical effects lead to the apparent polarization dependent beam shifts and changes of the beamwidth for different substrate materials and heights of the knife-pad.

  9. Influence of the substrate material on the knife-edge based profiling of tightly focused light beams

    NASA Astrophysics Data System (ADS)

    Huber, C.; Orlov, S.; Banzer, P.; Leuchs, G.

    2016-04-01

    The performance of the knife-edge method as a beam profiling technique for tightly focused light beams depends on several parameters, such as the material and height of the knife-pad as well as the polarization and wavelength of the focused light beam under study. Here we demonstrate that the choice of the substrate the knife-pads are fabricated on has a crucial influence on the reconstructed beam projections as well. We employ an analytical model for the interaction of the knife-pad with the beam and report good agreement between our numerical and experimental results. Moreover, we simplify the analytical model and demonstrate, in which way the underlying physical effects lead to the apparent polarization dependent beam shifts and changes of the beamwidth for different substrate materials and heights of the knife-pad.

  10. Numerical modeling of tectonically driven river dynamics and deposition in an upland incised valley

    NASA Astrophysics Data System (ADS)

    Bianchi, Valeria; Salles, Tristan; Ghinassi, Massimiliano; Billi, Paolo; Dallanave, Edoardo; Duclaux, Guillaume

    2015-07-01

    Within upstream reaches of incised valleys, fluvial sedimentation occurs where it is controlled by interaction between climate and tectonics. This study focuses on a Plio-Pleistocene fluvial paleovalley, which drained the northeastern margin of Siena basin (northern Apennines, Italy). Valley filling resulted from the interaction between river drainage and active normal faults striking perpendicular and parallel to the main valley. Through numerical modeling, this study aims to refine temporal and spatial mesoscale deposit variations, which highlight the upset of fluvial architectures derived from the interplay between the river system and uplift. Geomorphological and hydrodynamic parameter calibration was performed integrating field studies with paleohydraulic and paleomagnetic data. The numerical model simulates the evolution of valley formation with the development of (i) a pre-tectonic steady state system, followed by (ii) a syntectonic aggradation and avulsion phase, and (iii) a post-tectonic relaxation phase. The syntectonic phase shows fine sediment back-filling upstream of the uplifted area and coarse sediment down-filling downstream of the upwarping. The recorded aggradations are asynchronous with upstream deposition preceding downstream deposition.

  11. Acute necrosis after Gamma Knife surgery in vestibular schwannoma leading to multiple cranial nerve palsies.

    PubMed

    Kapitza, Sandra; Pangalu, Athina; Horstmann, Gerhard A; van Eck, Albert T; Regli, Luca; Tarnutzer, Alexander A

    2016-08-01

    We discuss a rare acute complication after Gamma Knife therapy (Elekta AB, Stockholm, Sweden) in a single patient. A 52-year-old woman presented with vertigo, facial weakness and hearing loss emerging 48hours following Gamma Knife radiosurgery for a right-sided vestibular schwannoma. Neurological examination 6days after symptom onset showed right-sided facial palsy, spontaneous left-beating nystagmus and pathologic head-impulse testing to the right. Pure-tone audiogram revealed right-sided sensorineural hearing loss. A diagnosis of acute vestibulocochlear and facial neuropathy was made. Brain MRI demonstrated focal contrast sparing within the schwannoma, likely related to acute radiation necrosis. Acute multiple cranial neuropathies of the cerebellopontine angle after Gamma Knife treatment should raise suspicion of acute tissue damage within the schwannoma and should result in urgent MRI. Treatment with steroids may be considered based on accompanying swelling and edema. Copyright © 2016 Elsevier Ltd. All rights reserved.

  12. Image-guided robotic radiosurgery (CyberKnife) for pancreatic insulinoma: is laparoscopy becoming old?

    PubMed

    Huscher, Cristiano Germano Sigismondo; Mingoli, Andrea; Sgarzini, Giovanna; Mereu, Andrea; Gasperi, Maurizio

    2012-03-01

    Insulinomas constitute about 25% of endocrine pancreatic tumors. Laparoscopic surgery is the treatment of choice. However, pancreas-related complications rate is very high, even in experienced hands, ranging up to 37%. Alternative procedures such as embolization with trisacryl have not been accepted by the surgical community. Image-guided robotic radiosurgery or stereotactic radiosurgery (CyberKnife) is a minimally invasive procedure delivering large doses of ionizing radiation to a well-defined target. CyberKnife radiosurgery is successfully used in brain cancer, lung cancer, prostate cancer, liver metastases, kidney cancer, and pancreatic cancer. The authors present the first case to their knowledge of a benign functioning insulinoma successfully treated by a CyberKnife technique with a 3-year follow-up.

  13. Gamma Knife radiosurgery in pituitary adenomas: Why, who, and how to treat?

    PubMed

    Castinetti, Frederic; Brue, Thierry

    2010-08-01

    Pituitary adenomas are benign tumors that can be either secreting (acromegaly, Cushing's disease, prolactinomas) or non-secreting. Transsphenoidal neurosurgery is the gold standard treatment; however, it is not always effective. Gamma Knife radiosurgery is a specific modality of stereotactic radiosurgery, a precise radiation technique. Several studies reported the efficacy and low risk of adverse effects induced by this technique: in secreting pituitary adenomas, hypersecretion is controlled in about 50% of cases and tumor volume is stabilized or decreased in 80-90% of cases, making Gamma Knife a valuable adjunctive or first-line treatment. As hormone levels decrease progressively, the main drawback is the longer time to remission (12-60 months), requiring an additional treatment during this period. Hypopituitarism is the main side effect, observed in 20-40% cases. Gamma Knife is thus useful in the therapeutic algorithms of pituitary adenomas in well-defined indications, mainly low secreting small lesions well identified on magnetic resonance imaging (MRI).

  14. [Acupoint position and manipulation of needle knife treating shoulder bi syndrome].

    PubMed

    Zhao, Li; Guo, Changqing

    2016-03-01

    With Jianyu (LI 15), Jianliao (TE 14) and Jianzhen (SI 9) for instance, the three acupoints used to treat shoulder bi syndrome by needle knife, and through traceability and researching constant structure, the acupoint position, insertion trace, manipulation and clinical significance of needle knife medicine were discussed. Accurate position is one of the characteristics of acupoints selection of needle knife medicine. As for the acupoints selection method, the mean of body surface localization is always used. The phanerous or palpable bone processes, muscles and tendons are taken as positioning marks; pressing areas where appear sour, numb, or distensible and other sensations is considered as the principle of press positioning. So acupoints position method is the combination of observation and palpation. Different insertion methods can effectively relieve the accretive bursae synovialis, tendon, joint capsule and the compressed nerve, so that shoulder bi syndrome is relieved.

  15. A quality assurance program in stereotactic radiosurgery using the Gamma Knife unit.

    PubMed

    Stuecklschweiger, G F; Feichtinger, K

    1998-10-01

    Because of the large single-fraction dose in stereotactic radiosurgery it is important to guarantee a high geometric and dosimetric accuracy. The paper represent the quality assurance program for the Gamma Knife unit at the University Clinic of Neurosurgery in Graz. The program includes the following procedures: timer control, mechanical radiation isocenter coincidence, trunnion centricity, helmet microswitches test, radiation output and relative helmet factors, dose profile verification, safety interlocks checks and software quality assurance. In summary, the mechanical accuracy and reproducibility of the Gamma Knife unit are < 1 mm. The geometric failure in stereotactic Gamma Knife treatment is limited by the human error in setting the clinical target volume and the spatial accuracy of dose delivery to the patient is limited by the accuracy of modern target localization procedures.

  16. Splitting of tungsten wire in the knife-edge compression test

    NASA Astrophysics Data System (ADS)

    Walter, J. L.; Briant, C. L.; Koch, E. F.

    1982-08-01

    As-drawn tungsten wire has been known to split and rolled tungsten sheet to delaminate if mishandled. The mechanism of splitting of tungsten wire in a knife-edge compression test was studied for a number of tungsten wires of different diameter, composition, processing history, and origin. The micro-structure of these wires was examined by optical, scanning, and transmission electron microscopy. Grain boundary composition was determined by Auger electron spectroscopy. A correlation between the number of transverse boundaries in the microstructure and the split load in the knife-edge compression test was observed; the greater the number of transverse boundaries, the lower the load required to induce a split. This relationship held for all wires, regardless of the history of the wire. It was concluded that transverse grain or subgrain boundaries are responsible for initiating splits in the knife-edge compression test. The mechanism of splitting is discussed.

  17. A constrained tracking algorithm to optimize plug patterns in multiple isocenter Gamma Knife radiosurgery planning

    SciTech Connect

    Li Kaile; Ma Lijun

    2005-10-15

    We developed a source blocking optimization algorithm for Gamma Knife radiosurgery, which is based on tracking individual source contributions to arbitrarily shaped target and critical structure volumes. A scalar objective function and a direct search algorithm were used to produce near real-time calculation results. The algorithm allows the user to set and vary the total number of plugs for each shot to limit the total beam-on time. We implemented and tested the algorithm for several multiple-isocenter Gamma Knife cases. It was found that the use of limited number of plugs significantly lowered the integral dose to the critical structures such as an optical chiasm in pituitary adenoma cases. The main effect of the source blocking is the faster dose falloff in the junction area between the target and the critical structure. In summary, we demonstrated a useful source-plugging algorithm for improving complex multi-isocenter Gamma Knife treatment planning cases.

  18. Stereotaxic gamma knife surgery in treatment of critically located pilocytic astrocytoma: preliminary result

    PubMed Central

    Hafez, Raef FA

    2007-01-01

    Background Low-grade gliomas are uncommon primary brain tumors, located more often in the posterior fossa, optic pathway, and brain stem and less commonly in the cerebral hemispheres. Case presentations Two patients with diagnosed recurrent cystic pilocytic astrocytoma critically located within the brain (thalamic and brain stem) were treated with gamma knife surgery. Gamma knife surgery (GKS) did improve the patient's clinical condition very much which remained stable later on. Progressive reduction on the magnetic resonance imaging (MRI) studies of the solid part of the tumor and almost disappearance of the cystic component was achieved within the follow-up period of 36 months in the first case with the (thalamic located lesion) and 22 months in the second case with the (brain stem located lesion). Conclusion Gamma knife surgery represents an alternate tool in the treatment of recurrent and/or small postoperative residual pilocytic astrocytoma especially if they are critically located PMID:17394660

  19. [Stereotactic Body Radiotherapy with CyberKnife®for Liver Metastases from Colorectal Cancer].

    PubMed

    Mihara, Koki; Kaihara, Masaki; Sunahori, Sayaka; Yamashiro, Naotsugu; Nishiya, Shin; Ito, Yasuhiro; Funakoshi, Kazuto; Egawa, Tomohisa; Tsukamoto, Nobuhiro; Nagashima, Atsushi

    2015-10-01

    For treatment of colorectal liver metastases, liver resection is recommended for resectable cases in the clinical guidelines for colorectal cancer. On the other hand, there are currently no data supporting the efficacy of radiation therapy as a topical treatment, and this treatment can therefore not presently be recommended. With CyberKnife®, it is possible to perform stereotactic radiation therapy using a linear accelerator with high accuracy, even for lesions in the trunk area such as liver metastases. Between December 2009 and September 2014 in our hospital, we performed radiation treatment using CyberKnife® for 14 cases with 22 colorectal liver metastases. As a result, we obtained response and local control rates of 76.2%and 81.0%, respectively. Moreover, no advanced adverse events were observed. Thus, we consider that CyberKnife® treatment for colorectal liver metastases is effective as a topical treatment, with low invasiveness and high safety.

  20. Cleaning mechanism of particle contaminants on large aperture optical components by using air knife sweeping technology

    NASA Astrophysics Data System (ADS)

    Niu, Longfei; Liu, Hao; Miao, Xinxiang; Lv, Haibing; Yuan, Xiaodong; Zhou, Hai; Yao, Caizhen; Zhou, Guorui; Li, Qin

    2017-05-01

    The cleaning mechanism of optical surface particle contaminants in the light pneumatic tube was simulated based on the static equations and JKR model. Cleaning verification experiment based on air knife sweeping system and on-line monitoring system in high power laser facility was set up in order to verify the simulated results. Results showed that the removal ratio is significantly influenced by sweeping velocity and angle. The removal ratio can reach to 94.3% by using higher input pressure of the air knife, demonstrating that the air knife sweeping technology is useful for maintaining the surface cleanliness of optical elements, and thus guaranteeing the long-term stable running of the high power laser facility.

  1. Epithelial and connective tissue healing following electrosurgical incisions in human gingiva.

    PubMed

    Kalkwarf, K L; Krejci, R F; Wentz, F M; Edison, A R

    1983-02-01

    Electrosurgery is used for intraoral incisions by many clinicians. Much controversy surrounds the effect of lateral heat produced during the electrosurgical incision upon the healing of adjacent connective tissue. Ten electrosurgical incisions were made in the gingiva in each of five adult male volunteers. The duration of incision and actual energy production for each incision were calculated. Excisional biopsies of the incisions were obtained at 0-504 hours. At the light microscopic level, epithelium, totally degenerated immediately following the electrosurgery incision, showed extensive activity at 24-48 hours and had covered all wounds by 72 hours. Early hour specimens showed a homogenous connective tissue region, adjacent to the wound site, devoid of cells and fibers. This zone of denatured connective tissue gradually diminished until it was no longer present at 396 hours.

  2. Modified facelift incision for partial parotidectomy versus bayonet-shaped incision: a comparison using visual analog scale.

    PubMed

    Bulut, Olcay Cem; Plinkert, Peter; Federspil, Philippe A

    2016-10-01

    The aim of this study is to show differences between a modified facelift incision (MFI) for partial parotidectomy versus a bayonet-shaped incision (BSI). 24 patients presenting with a parotid tumor were surgically treated with a partial parotidectomy using a MFI. We generated a "matched pair control group" regarding age, tumor size and gender, who received a BSI. A questionnaire was sent to all patients and relevant data reviewed. The cosmetic satisfaction on a VAS with a MFI was 9.74 (±0.47) compared to BSI with 7.63 (±2.44, p = 0.004). The scoring in the two subgroups "visible scar" and "people noticed my surgery" was significantly better in the MFI group The postoperative skin numbness, skin depression, facial nerve function postoperatively showed no statistical differences. The MFI for parotid tumors has a better outcome than the BSI regarding cosmetic satisfaction and visible scarring.

  3. Bedrock River Incision Following Aggradation: Observations from the Waipaoa River Regarding Tributary Response to Mainstem Incision and the Role of Paleotopography

    NASA Astrophysics Data System (ADS)

    Crosby, B. T.; Whipple, K. X.

    2005-12-01

    Following a period of valley-filling aggradation, the form and extent of subsequent alluvial and bedrock incision is governed by the pre-aggradation topography and the position of the channel at the time of incision. We present findings from an extensive along-stream survey of the Waihuka Stream, a tributary to the Waipaoa River on the North Island of New Zealand. Never glaciated, this basin aggraded 5 to 25 m of coarse alluvial sediment during the last glacial period, creating an extensive and distinctive valley-fill surface. ~18 ka, aggradation ceased and a subsequent pulse of fluvial incision abandoned the aggradational surface. At present, the river gorge is incised 25 to 60 m into alluvial fill and mudstone bedrock beneath the top of the aggradational surface. Using a laser range-finder and GPS-enabled GIS surveying tool, we surveyed ~17 km of the Waihuka Stream (4.8×106 m2 to 6.3×107 m2). We collected a longitudinal profile and the relative elevations of fill and strath surfaces exposed in channel banks. We also surveyed a total of ~9 km in 14 tributaries to the Waihuka. Drainage areas of tributaries ranged between 5×105 m2 and 9.9×106 m2. In the Waihuka, we find that the amount of bedrock incision depends on whether the incising channel locally lowered through alluvial fill to reoccupy the preaggradation channel or whether it locally had to cut an entirely new valley into bedrock. Reaches dominated by bedrock incision were observed where alluvial fan deposits laterally shifted the mainstem channel out of the paleovalley and against the opposite bedrock hillslope. The along-stream variation in bed erodability forced by whether the re-incising channel encountered bedrock or alluvium had a significant effect on the propagation of the incision signal into tributaries. Where the channel dominantly re-incised alluvial fill, tributaries have stepped but not dramatically over-steepened longitudinal profiles that appear to be adjusting to the new base-level. In

  4. A cross-sectional study of knife injuries at a London major trauma centre.

    PubMed

    Pallett, J R; Sutherland, E; Glucksman, E; Tunnicliff, M; Keep, J W

    2014-01-01

    No national recording systems for knife injuries exist in the UK. Understanding the true size and nature of the problem of knife injuries is the first stage in reducing the burden of this injury. The aim of this study was to survey every knife injury seen in a single inner city emergency department (ED) over a one-year period. A cross-sectional observational study was performed of all patients attending with a knife injury to the ED of a London major trauma centre in 2011. Demographic characteristics, patterns of injury, morbidity and mortality data were collected. A total of 938 knife injuries were identified from 127,191 attendances (0.77% of all visits) with a case fatality rate of 0.53%. A quarter (24%) of the major trauma team's caseload was for knife injuries. Overall, 44% of injuries were selfreported as assaults, 49% as accidents and 8% as deliberate self-harm. The highest age specific incident rate occurred in the 16-24 year age category (263/100,000). Multiple injuries were seen in 19% of cases, of which only 81% were recorded as assaults. The mean length of stay for those admitted to hospital was 3.04 days. Intrathoracic injury was seen in 26% of cases of chest trauma and 24% of abdominal injuries had a second additional chest injury. Violent intentional injuries are a significant contributory factor to the workload of the major trauma team at this centre. This paper contributes to a more comprehensive understanding of the nature of these injuries seen in the ED.

  5. A cross-sectional study of knife injuries at a London major trauma centre

    PubMed Central

    Sutherland, E; Glucksman, E; Tunnicliff, M; Keep, JW

    2014-01-01

    INTRODUCTION No national recording systems for knife injuries exist in the UK. Understanding the true size and nature of the problem of knife injuries is the first stage in reducing the burden of this injury. The aim of this study was to survey every knife injury seen in a single inner city emergency department (ED) over a one-year period. METHODS A cross-sectional observational study was performed of all patients attending with a knife injury to the ED of a London major trauma centre in 2011. Demographic characteristics, patterns of injury, morbidity and mortality data were collected. RESULTS A total of 938 knife injuries were identified from 127,191 attendances (0.77% of all visits) with a case fatality rate of 0.53%. A quarter (24%) of the major trauma team’s caseload was for knife injuries. Overall, 44% of injuries were selfreported as assaults, 49% as accidents and 8% as deliberate self-harm. The highest age specific incident rate occurred in the 16–24 year age category (263/100,000). Multiple injuries were seen in 19% of cases, of which only 81% were recorded as assaults. The mean length of stay for those admitted to hospital was 3.04 days. Intrathoracic injury was seen in 26% of cases of chest trauma and 24% of abdominal injuries had a second additional chest injury. CONCLUSIONS Violent intentional injuries are a significant contributory factor to the workload of the major trauma team at this centre. This paper contributes to a more comprehensive understanding of the nature of these injuries seen in the ED. PMID:24417825

  6. Peroral endoscopic myotomy using FlushKnife BT: a single-center series.

    PubMed

    Tanaka, Shinwa; Toyonaga, Takashi; Kawara, Fumiaki; Grimm, Ian S; Hoshi, Namiko; Abe, Hirofumi; Ohara, Yoshiko; Morita, Yoshinori; Umegaki, Eiji; Azuma, Takeshi

    2017-07-01

    Peroral endoscopic myotomy (POEM) is an evolving new treatment strategy for achalasia. Although several kinds of electrosurgical knives have been used in performing POEM, the best device has yet to be determined. The FlushKnife BT is a waterjet-emitting short needle-knife with a small ball tip (BT) that offers the potential to perform all aspects of POEM with a single device. In this study, we evaluated the safety and efficiency of the FlushKnife BT for POEM.  A total of 54 consecutive patients with achalasia and other spastic esophageal motility disorders, such as jackhammer esophagus or distal esophageal spasm, who underwent POEM between January 2016 and August 2016, were included in this retrospective study.  The median operation time was 73.0 minutes (range 39 - 184 minutes). All procedures were completed using only the FlushKnife BT without changing to any other electrosurgical instrument. The median number of additional submucosal injections with an injection needle was 0 (range 0 - 1). Endoscopic vessel sealing was performed a mean of 3 times (range 0 - 7). The median number of bleeding episodes requiring treatment with hemostatic forceps was 0 (range 0 - 5). There were no significant adverse events. Seven of 52 patients (13.5 %) reported symptoms of gastroesophageal reflux disease such as heartburn or acid reflux at 3 month follow-up.  The FlushKnife BT enabled POEM to be performed with very few device exchanges, either for re-injection or to control intraoperative bleeding. In this uncontrolled case series, the ability of the FlushKnife BT to perform nearly all aspects of the POEM procedure seems to make it particularly well suited to this procedure.

  7. Thermal welding vs. cold knife tonsillectomy: a comparison of voice and speech.

    PubMed

    Celebi, Saban; Yelken, Kursat; Celik, Oner; Taskin, Umit; Topak, Murat

    2011-01-01

    To compare acoustic, aerodynamic and perceptual voice and speech parameters in thermal welding system tonsillectomy and cold knife tonsillectomy patients in order to determine the impact of operation technique on voice and speech. Thirty tonsillectomy patients (22 children, 8 adults) participated in this study. The preferred technique was cold knife tonsillectomy in 15 patients and thermal welding system tonsillectomy in the remaining 15 patients. One week before and 1 month after surgery the following parameters were estimated: average of fundamental frequency, Jitter, Shimmer, harmonic to noise ratio, formant frequency analyses of sustained vowels. Perceptual speech analysis and aerodynamic measurements (maximum phonation time and s/z ratio) were also conducted. There was no significant difference in any of the parameters between cold knife tonsillectomy and thermal welding system tonsillectomy groups (p>0.05). When the groups were contrasted among themselves with regards to preoperative and postoperative rates, fundamental frequency was found to be significantly decreased after tonsillectomy in both of the groups (p<0.001). First formant for the vowel /a/ in the cold knife tonsillectomy group and for the vowel /i/ in the thermal welding system tonsillectomy group, second formant for the vowel /u/ in the thermal welding system tonsillectomy group and third formant for the vowel /u/ in the cold knife tonsillectomy group were found to be significantly decreased (p<0.05). The surgical technique, whether it is cold knife or thermal welding system, does not appear to affect voice and speech in tonsillectomy patients. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

  8. Comparison of the results of open carpal tunnel release and KnifeLight carpal tunnel release.

    PubMed

    Yeo, K Q; Yeo, E M N

    2007-12-01

    The study compares the results of open release of carpal tunnel syndrome with a release done with a proprietary instrument, the KnifeLight, which uses a minimal access approach. A retrospective study was conducted on two groups of patients operated on by the same surgeon between January 1998 and August 2002. All cases presented with numbness of six months duration or more, and a positive Phalen's test. Open carpal tunnel release was done in the first group of 26 consecutive patients before the KnifeLight was introduced in January 2000. The KnifeLight technique was used in a second consecutive group of 49 patients. In two patients, the KnifeLight procedure was abandoned because the median nerve could not be safely separated from the transverse carpal ligament. The two groups were shown to be comparable with respect to clinical presentation and nerve conduction studies. There was no complication in both groups. However, no advantage could be demonstrated in the use of the KnifeLight procedure as compared to the open procedure in respect to improvement in pain, numbness or patient satisfaction. The study also showed that the severity of nerve conduction changes is not related to the severity of numbness. It is also not a good guide to the improvement of numbness and patient satisfaction after the operation. The method was found to be acceptable to patients as an office procedure. The cost of doing either procedure is reduced when done as an office procedure, but there is a cost incurred in the use of the KnifeLight instrument.

  9. Maylard incision in gynecologic surgery: 4-year experience in Thammasat University Hospital.

    PubMed

    Manusook, Sakol; Suwannarurk, Komsun; Pongrojpaw, Densak; Bhamarapravatana, Kornkarn

    2014-08-01

    To present the results of Maylard incisionfor gynecologic surgery in Thammasat University Hospital during the past four years. A retrospective study of gynecologic surgery performed via the Maylard muscle cutting incision compare to Pfannenstiel muscle splitting and midline incision. Data came from subjects who underwent gynecologic surgey at Thammasat University Hospital, Pathumthani, Thailand friom January 2010 to December 2013. In the period of 4 years, there were 283 cases of elective surgery that performed via Maylard, Pfannenstiel and midline incision by the single experience gynecologic surgeon team. One hundred and six cases were performed via Maylard incision technique. The remaining 59 and 118 cases were performed via Pfannenstiel and midline incision technique, respectively. Two-thirds and one-thirds of cases underwent hysterectomy and conservative surgery, respectively. Benign conditions were the major indicationfor surgery at the percentage of 83.4. Operative results were not significantly different from well-known midline and Pfannenstiel incision in terms of blood loss, time to first meal and postoperative pain. Operative time in Maylard incision was longer than in Pfannenstiel incision. Length of stay in Maylard incision was longer than Pfannenstiel but shorter than midline incision. Overall complications (eoperation, bowel injuries, urinary bladder injuries and blood transfusion rate) were not significantly different. Maylard incision provides similar operative results with midline and Pfannenstiel technique. Even though it takes more time for abdominal entry but it gives more operative exposure than Pfannenstiel incision. In the woman with previous low transverse scar and gynaecologic surgery is needed, Maylard incision could be an optional technique that provides cosmetic and successfud results. Hand on training for Maylard incision from their mentors should be encouraged to more practice.

  10. In vivo architectural analysis of clear corneal incisions using anterior segment optical coherence tomography.

    PubMed

    Dupont-Monod, Sylvère; Labbé, Antoine; Fayol, Nicolas; Chassignol, Alexis; Bourges, Jean-Louis; Baudouin, Christophe

    2009-03-01

    To use anterior segment optical coherence tomography (AS-OCT) to analyze the in vivo architecture of clear corneal incisions after phacoemulsification using different techniques. Department of Ophthalmology, Quinze-Vingts National Ophthalmology Hospital, Paris, France. This prospective observational study analyzed clear corneal incisions used in phacoemulsification. All wounds were evaluated 1 day and 8 days postoperatively by AS-OCT (Visante). Incision architecture and pachymetry at the wound level were analyzed. Thirty-five clear corneal incisions were analyzed. Six eyes had 2.75 mm coaxial phacoemulsification, 19 had 2.20 mm microincision coaxial phacoemulsification, and 10 had 1.30 mm bimanual microincision phacoemulsification. The 1.30 mm incision had a straight-line configuration. The 2.20 mm and 2.75 mm incisions had an arcuate configuration. The angles of incidence of 1.30 mm incisions were greater than those of 2.20 mm incisions (P<.001). All incisions had slight corneal edema limited to the incision area. The edema was slightly greater around 1.30 mm incisions (mean pachymetry 1143 microm +/- 140 [SD]) than around 2.20 mm incisions (mean 1012 +/- 101 microm) (P = .001). Bimanual procedures had satisfactory endothelial apposition in the enlarged areas, where stromal edema was less than that surrounding the unenlarged 1.30 mm incisions. The 3 phacoemulsification techniques induced gaping of the endothelial edge, minor inadequate endothelial apposition, and mild stromal edema in the area of the clear corneal incisions. Bimanual microincision sleeveless phacoemulsification may alter the wound slightly more than coaxial 2.75 mm and microcoaxial 2.20 mm sleeved-tip phacoemulsification.

  11. Development of relaxation turbulence models

    NASA Technical Reports Server (NTRS)

    Hung, C. M.

    1976-01-01

    Relaxation turbulence models have been intensively studied. The complete time dependent mass averaged Navier-Stokes equations have been solved for flow into a two dimensional compression corner. A new numerical scheme has been incorporated into the developed computed code with an attendant order of magnitude reduction in computation time. Computed solutions are compared with experimental measurements of Law for supersonic flow. Details of the relaxation process have been studied; several different relaxation models, including different relaxation processes and varying relaxation length, are tested and compared. Then a parametric study has been conducted in which both Reynolds number and wedge angle are varied. To assess effects of Reynolds number and wedge angle, the parametric study includes the comparison of computed separation location and upstream extent of pressure rise; numerical results are also compared with the measurements of surface pressure, skin friction and mean velocity field.

  12. Reliability of the frozen section in sharp knife cone biopsy of the cervix.

    PubMed

    Woodford, H D; Poston, W; Elkins, T E

    1986-10-01

    Eight patient records were reviewed following cold knife conization in which frozen section diagnosis was utilized to aid the surgeon in formulating appropriate therapy after conization. Two patients were diagnosed as having microinvasive squamous cell carcinoma on final pathology when frozen sections were read as showing no invasion. Furthermore, in the 51 instances in which a degree of cervical dysplasia was determined from frozen sections, 14 discrepancies were noted on final pathology (27%). Such discrepancies may lead to unnecessary hysterectomies performed for cervical dysplasia that is easily treated with outpatient office procedures, especially when cold knife conization and frozen section diagnosis are performed without prior colposcopy and biopsy.

  13. Successful Treatment of Eccrine Porocarcinoma Metastasized to a Cervical Lymph Node with CyberKnife Radiosurgery.

    PubMed

    Fujimura, Taku; Hashimoto, Akira; Furudate, Sadanori; Kambayashi, Yumi; Haga, Takahiro; Aiba, Setsuya

    2014-05-01

    Eccrine porocarcinoma is a rare type of skin cancer that originates from eccrine sweat glands or acrosyringium and mainly occurs in the elderly. In this report, we describe an 85-year-old Japanese woman with eccrine porocarcinoma that metastasized to a cervical lymph node who was cured with CyberKnife radiosurgery. Because our patient had a high risk of perioperative complication, standard surgical therapy with a wide margin was impractical. Our present study suggests the novel possibility of using CyberKnife for the treatment of inoperable metastatic porocarcinoma.

  14. Gamma knife radiosurgery for Cushing's disease and Nelson's syndrome.

    PubMed

    Marek, Josef; Ježková, Jana; Hána, Václav; Kršek, Michal; Liščák, Roman; Vladyka, Vilibald; Pecen, Ladislav

    2015-06-01

    This paper presents our 18 years of experience in treating ACTH secreting adenomas (Cushing's disease and Nelson's syndrome) using the Leksell gamma knife (LGK) irradiation. Twenty-six patients with Cushing's disease were followed-up after LGK irradiation for 48-216 months (median 78 months). Seventeen patients had undergone previous surgery, in nine patients LGK irradiation was the primary therapy. Furthermore, 14 patients with Nelson's syndrome were followed-up for 30-204 months (median 144 months). LGK treatment resulted in hormonal normalization in 80.7 % of patients with Cushing's disease. Time to normalization was 6-54 months (median 30 months). The volume of the adenoma decreased in 92.3% (in 30.7% disappeared completely). There was no recurrence of the disease. In all 14 patients with Nelson's syndrome ACTH levels decreased (in two patients fully normalized) their ACTH levels. When checked up 5-10 years after irradiation regrowth of the adenoma was only detected in one patient (9.1%), in 27.3% adenoma volume remained unchanged, in 45.4% adenoma volume decreased and in 18.2% adenoma completely disappeared. Hypopituitarism did not develop in any patient where the critical dose to the pituitary and distal infundibulum was respected. LGK radiation represents an effective and well-tolerated option for the treatment of patients with Cushing's disease after unsuccessful surgery and may be valuable even as a primary treatment in patients who are not suitable for, or refuse, surgery. In the case of Nelson's syndrome it is possible to impede tumorous growth and control the size of the adenoma in almost all patients.

  15. Clinical outcomes following salvage Gamma Knife radiosurgery for recurrent glioblastoma

    PubMed Central

    Larson, Erik W; Peterson, Halloran E; Lamoreaux, Wayne T; MacKay, Alexander R; Fairbanks, Robert K; Call, Jason A; Carlson, Jonathan D; Ling, Benjamin C; Demakas, John J; Cooke, Barton S; Lee, Christopher M

    2014-01-01

    Glioblastoma multiforme (GBM) is the most common malignant primary brain tumor with a survival prognosis of 14-16 mo for the highest functioning patients. Despite aggressive, multimodal upfront therapies, the majority of GBMs will recur in approximately six months. Salvage therapy options for recurrent GBM (rGBM) are an area of intense research. This study compares recent survival and quality of life outcomes following Gamma Knife radiosurgery (GKRS) salvage therapy. Following a PubMed search for studies using GKRS as salvage therapy for malignant gliomas, nine articles from 2005 to July 2013 were identified which evaluated rGBM treatment. In this review, we compare Overall survival following diagnosis, Overall survival following salvage treatment, Progression-free survival, Time to recurrence, Local tumor control, and adverse radiation effects. This report discusses results for rGBM patient populations alone, not for mixed populations with other tumor histology grades. All nine studies reported median overall survival rates (from diagnosis, range: 16.7-33.2 mo; from salvage, range: 9-17.9 mo). Three studies identified median progression-free survival (range: 4.6-14.9 mo). Two showed median time to recurrence of GBM. Two discussed local tumor control. Six studies reported adverse radiation effects (range: 0%-46% of patients). The greatest survival advantages were seen in patients who received GKRS salvage along with other treatments, like resection or bevacizumab, suggesting that appropriately tailored multimodal therapy should be considered with each rGBM patient. However, there needs to be a randomized clinical trial to test GKRS for rGBM before the possibility of selection bias can be dismissed. PMID:24829861

  16. Cavernomas: Outcomes after gamma-knife radiosurgery in Iran

    PubMed Central

    Azimi, Parisa; Shahzadi, Sohrab; Bitaraf, Mohammad Ali; Azar, Maziar; Alikhani, Mazdak; Zali, Alireza; Sadeghi, Sohrab

    2015-01-01

    Background: Treatment of cavernomas remains a challenge in surgically inaccessible regions. The purpose of this study was to evaluate outcomes after gamma-knife surgery (GKS) for these patients. Materials and Methods: A retrospective review of 100 patients treated between 2003 and 2011 was conducted in order to evaluate hemorrhage rates, complications, radiation effects after GKS. Dosage at the tumor margin was stratified into two groups: those that received ≤13 Gy; and those who received >13 Gy. The demographic and clinical characteristics of patients including age, gender, and hemorrhage rates were extracted from care records. Results: The median age was 32.5 years (ranging from 15 to 79). 44% were female. The median follow-up time was 42.2 months (ranging from 24 to 90). The median volume of the lesions was 1050.0 mm3 (ranging from 112.0 to 4100.0) before GKS. A reduction of 27.5% in median size of cavernomas was achieved at the last follow-up. There was 12% treatment-related morbidity after GKS. The hemorrhage rate in the first 2 years after GKS was 4.1% and 1.9% thereafter. There was no mortality due to GKS, and 93 patients were alive at the last follow-up. The radiation-related complication developed with marginal dose 13 Gy. Conclusion: The GKS for cavernomas appears to be a safe and beneficial in carefully selected patients. Low-dose GKS may be effective for the management of cavernous malformations. PMID:25767582

  17. Gamma Knife radiosurgery for hemangioma of the cavernous sinus.

    PubMed

    Lee, Cheng-Chia; Sheehan, Jason P; Kano, Hideyuki; Akpinar, Berkcan; Martinez-Alvarez, Roberto; Martinez-Moreno, Nuria; Guo, Wan-Yuo; Lunsford, L Dade; Liu, Kang-Du

    2017-05-01

    OBJECTIVE Cavernous sinus hemangiomas (CSHs) are rare vascular tumors. A direct microsurgical approach usually results in massive hemorrhage and incomplete tumor resection. Although stereotactic radiosurgery (SRS) has emerged as a therapeutic alternative to microsurgery, outcome studies are few. Authors of the present study evaluated the role of SRS for CSH. METHODS An international multicenter study was conducted to review outcome data in 31 patients with CSH. Eleven patients had initial microsurgery before SRS, and the other 20 patients (64.5%) underwent Gamma Knife SRS as the primary management for their CSH. Median age at the time of radiosurgery was 47 years, and 77.4% of patients had cranial nerve dysfunction before SRS. Patients received a median tumor margin dose of 12.6 Gy (range 12-19 Gy) at a median isodose of 55%. RESULTS Tumor regression was confirmed by imaging in all 31 patients, and all patients had greater than 50% reduction in tumor volume at 6 months post-SRS. No patient had delayed tumor growth, new cranial neuropathy, visual function deterioration, adverse radiation effects, or hypopituitarism after SRS. Twenty-four patients had presented with cranial nerve disorders before SRS, and 6 (25%) of them had gradual improvement. Four (66.7%) of the 6 patients with orbital symptoms had symptomatic relief at the last follow-up. CONCLUSIONS Stereotactic radiosurgery was effective in reducing the volume of CSH and attaining long-term tumor control in all patients at a median of 40 months. The authors' experience suggests that SRS is a reasonable primary and adjuvant treatment modality for patients in whom a CSH is diagnosed.

  18. Real-time inverse planning for Gamma Knife radiosurgery.

    PubMed

    Wu, Q Jackie; Chankong, Vira; Jitprapaikulsarn, Suradet; Wessels, Barry W; Einstein, Douglas B; Mathayomchan, Boonyanit; Kinsella, Timothy J

    2003-11-01

    The challenges of real-time Gamma Knife inverse planning are the large number of variables involved and the unknown search space a priori. With limited collimator sizes, shots have to be heavily overlapped to form a smooth prescription isodose line that conforms to the irregular target shape. Such overlaps greatly influence the total number of shots per plan, making pre-determination of the total number of shots impractical. However, this total number of shots usually defines the search space, a pre-requisite for most of the optimization methods. Since each shot only covers part of the target, a collection of shots in different locations and various collimator sizes selected makes up the global dose distribution that conforms to the target. Hence, planning or placing these shots is a combinatorial optimization process that is computationally expensive by nature. We have previously developed a theory of shot placement and optimization based on skeletonization. The real-time inverse planning process, reported in this paper, is an expansion and the clinical implementation of this theory. The complete planning process consists of two steps. The first step is to determine an optimal number of shots including locations and sizes and to assign initial collimator size to each of the shots. The second step is to fine-tune the weights using a linear-programming technique. The objective function is to minimize the total dose to the target boundary (i.e., maximize the dose conformity). Results of an ellipsoid test target and ten clinical cases are presented. The clinical cases are also compared with physician's manual plans. The target coverage is more than 99% for manual plans and 97% for all the inverse plans. The RTOG PITV conformity indices for the manual plans are between 1.16 and 3.46, compared to 1.36 to 2.4 for the inverse plans. All the inverse plans are generated in less than 2 min, making real-time inverse planning a reality.

  19. Salvage Gamma Knife Stereotactic Radiosurgery for Surgically Refractory Trigeminal Neuralgia

    SciTech Connect

    Little, Andrew S.; Shetter, Andrew G. Shetter, Mary E.; Kakarla, Udaya K.; Rogers, C. Leland

    2009-06-01

    Purpose: To evaluate the clinical outcome of patients with surgically refractory trigeminal neuralgia (TN) treated with rescue gamma knife radiosurgery (GKRS). Methods and Materials: Seventy-nine patients with typical TN received salvage GKRS between 1997 and 2002 at the Barrow Neurological Institute (BNI). All patients had recurrent pain following at least one prior surgical intervention. Prior surgical interventions included percutaneous destructive procedures, microvascular decompression (MVD), or GKRS. Thirty-one (39%) had undergone at least two prior procedures. The most common salvage dose was 80 Gy, although 40-50 Gy was typical in patients who had received prior radiosurgery. Pain outcome was assessed using the BNI Pain Intensity Score, and quality of life was assessed using the Brief Pain Inventory. Results: Median follow-up after salvage GKRS was 5.3 years. Actuarial analysis demonstrated that at 5 years, 20% of patients were pain-free and 50% had pain relief. Pain recurred in patients who had an initial response to GKRS at a median of 1.1 years. Twenty-eight (41%) required a subsequent surgical procedure for recurrence. A multivariate Cox proportional hazards model suggested that the strongest predictor of GKRS failure was a history of prior MVD (p=0.029). There were no instances of serious morbidity or mortality. Ten percent of patients developed worsening facial numbness and 8% described their numbness as 'very bothersome.' Conclusions: GKRS salvage for refractory TN is well tolerated and results in long-term pain relief in approximately half the patients treated. Clinicians may reconsider using GKRS to salvage patients who have failed prior MVD.

  20. Gamma Knife Radiosurgery for Brain Metastases From Primary Breast Cancer

    SciTech Connect

    Kased, Norbert; Binder, Devin K.; McDermott, Michael W.; Nakamura, Jean L.; Huang, Kim; Berger, Mitchel S.; Wara, William M.; Sneed, Penny K.

    2009-11-15

    Purpose: The relative roles of stereotactic radiosurgery (SRS) vs. whole brain radiotherapy (WBRT) in the treatment of patients with brain metastases from breast cancer remain undefined. In this study, we reviewed our experience with these patients. Materials and Methods: We retrospectively reviewed all patients treated between 1991 and 2005 with Gamma Knife SRS for brain metastases from breast cancer. The actuarial survival and freedom from progression endpoints were calculated using the Kaplan-Meier method. Results: Between 1991 and 2005, 176 patients underwent SRS for brain metastases from breast cancer. The median survival time was 16.0 months for 95 newly diagnosed patients and 11.7 months for 81 patients with recurrent brain metastases. In the newly diagnosed patients, omission of upfront WBRT did not significantly affect the MST (p = .20), brain freedom from progression (p = .75), or freedom from new brain metastases (p = .83). Longer survival was associated with age <50 years, Karnofsky performance score >=70, primary tumor control, estrogen receptor positivity, and Her2/neu overexpression. No association was found between the number of treated brain metastases and the survival time. Conclusion: We have described prognostic factors for breast cancer patients treated with SRS for newly diagnosed or recurrent brain metastases. Most patient subsets had a median survival time of >=11 months. Unexpectedly, upfront WBRT did not appear to improve brain freedom from progression, and a larger number of brain metastases was not associated with a shorter survival time. Breast cancer might be distinct from other primary sites in terms of prognostic factors and the roles of WBRT and SRS for brain metastases.

  1. Gamma Knife Radiosurgery for the Treatment of Cystic Cerebral Metastases

    SciTech Connect

    Ebinu, Julius O.; Lwu, Shelly; Monsalves, Eric; Arayee, Mandana; Chung, Caroline; Laperriere, Normand J.; Kulkarni, Abhaya V.; Goetz, Pablo; Zadeh, Gelareh

    2013-03-01

    Purpose: To assess the role of Gamma Knife radiosurgery (GKRS) in the treatment of nonsurgical cystic brain metastasis, and to determine predictors of response to GKRS. Methods: We reviewed a prospectively maintained database of brain metastases patients treated at our institution between 2006 and 2010. All lesions with a cystic component were identified, and volumetric analysis was done to measure percentage of cystic volume on day of treatment and consecutive follow-up MRI scans. Clinical, radiologic, and dosimetry parameters were reviewed to establish the overall response of cystic metastases to GKRS as well as identify potential predictive factors of response. Results: A total of 111 lesions in 73 patients were analyzed; 57% of lesions received prior whole-brain radiation therapy (WBRT). Lung carcinoma was the primary cancer in 51% of patients, 10% breast, 10% colorectal, 4% melanoma, and 26% other. Fifty-seven percent of the patients were recursive partitioning analysis class 1, the remainder class 2. Mean target volume was 3.3 mL (range, 0.1-23 mL). Median prescription dose was 21 Gy (range, 15-24 Gy). Local control rates were 91%, 63%, and 37% at 6, 12, and 18 months, respectively. Local control was improved in lung primary and worse in patients with prior WBRT (univariate). Only lung primary predicted local control in multivariate analysis, whereas age and tumor volume did not. Lesions with a large cystic component did not show a poorer response compared with those with a small cystic component. Conclusions: This study supports the use of GKRS in the management of nonsurgical cystic metastases, despite a traditionally perceived poorer response. Our local control rates are comparable to a matched cohort of noncystic brain metastases, and therefore the presence of a large cystic component should not deter the use of GKRS. Predictors of response included tumor subtype. Prior WBRT decreased effectiveness of SRS for local control rates.

  2. Trigeminal neuralgia pain relief after gamma knife stereotactic radiosurgery.

    PubMed

    Baschnagel, Andrew M; Cartier, Jacqueline L; Dreyer, Jason; Chen, Peter Y; Pieper, Daniel R; Olson, Rick E; Krauss, Daniel J; Maitz, Ann H; Grills, Inga Siiner

    2014-02-01

    To report outcomes of patients with medical and/or surgical refractory trigeminal neuralgia (TN) treated with gamma knife stereotactic radiosurgery (GK SRS). One hundred and forty-nine patients with 152 cases of TN treated with GK SRS were analyzed. All patients, except one, received a dose of 40Gy to the 50% isodose volume. The Barrow Neurological Institute (BNI) pain intensity score was used to grade pain. Actuarial rates of pain relief were calculated. Multiple factors were analyzed for association with pain relief. The median follow up was 27 months (4-71 months). Overall 92% of cases achieved a BNI score I-III after GK SRS. Of those who had pain relief after GK SRS, 32% developed pain recurrence defined as a BNI score of IV or V. The actuarial rate of freedom from pain recurrence (BNI scores I-III) of all treated cases at 1, 2 and 3-years was 76%, 69% and 60%, respectively. On univariate analysis age ≥70 was predictive of better pain relief (p=0.046). Type of pain, prior surgery, multiple sclerosis, number of isocenters, treated nerve length, volume and thickness and distance from the root entry zone to the isocenter were not significant for maintaining a BNI score of I-III. Those who achieved a BNI score of I or II were more likely to maintain pain relief compared to those who only achieved a BNI score of III (93% vs 38% at three years, p<0.01). The rate of pain relief of twenty-seven patients who underwent repeat GK SRS was 70% and 62% at 1 and 2 years, respectively. Toxicity after first GK SRS was minimal with 25% of cases experiencing only new or worsening post-treatment numbness. GK SRS provides acceptable pain relief with limited morbidity in patients with medical and/or surgical refractory TN. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Gamma knife radiosurgery of meningiomas involving the foramen magnum

    PubMed Central

    Starke, Robert M.; Nguyen, James H.; Reames, Davis L.; Rainey, Jessica; Sheehan, Jason P.

    2010-01-01

    Background: Foramen magnum meningiomas represent a challenging clinical entity. Although resection is performed for those with a mass effect, complete resection is not always feasible. For some patients, stereotactic radiosurgery may be used as the primary treatment modality. We evaluatedthe long-term outcome of Gamma Knife radiosurgery (GKRS) for the treatment of patientswith a foramen magnum meningioma. Materials and Methods: Between 1991 and 2005, 222 patients with a meningioma in the posterior fossa were treated with GKRS at the University of Virginia. Of these patients, 5 had meningiomas involving the foramen magnum. At the time of GKRS, the median age of the patients was 60 years (range, 51–78). Three patients were treated with radiosurgery following an initial resection and 2 were treated with upfront radiosurgery. The patients were assessed clinically and radiologically at routine intervals following GKRS. Results: The median tumor volume was 6.8 cc (range 1.9–17 cc). The GKRS tumor received a marginal dose of 12 Gy (range 10–15), and the median number of isocenters was 5 (range 3–19). The mean follow-up was 6 years (range 4–13). One lesion increased in size following GKRS requiring a second treatment, resulting in size stabilization. At the time of the last follow-up, all meningiomas had either demonstrated no growth (n = 4) or reduction in size (n = 1). No patients experienced post-radiotherapy complications. Conclusions: GKRS affords a high rate of tumor control and preservation of neurologic function for patients with foramen magnum meningiomas. Further study of its role in the neurosurgical management of such patients seems warranted. PMID:20890411

  4. Influence of Incision Location on Transmitter Loss, Healing, Survival, Growth, and Suture Retention of Juvenile Chinook Salmon

    SciTech Connect

    Panther, Jennifer L.; Brown, Richard S.; Gaulke, Greg L.; Deters, Katherine A.; Woodley, Christa M.; Eppard, M. Brad

    2011-11-01

    Fisheries research involving surgical implantation of transmitters necessitates the use of methods that minimize transmitter loss and fish mortality and optimize healing of the incision. We evaluated the effects of three incision locations on transmitter loss, healing, survival, growth, and suture retention in juvenile Chinook salmon Oncorhynchus tshawytscha. The three incision locations were (1) on the linea alba (LA incision), (2) adjacent and parallel to the LA (muscle-cutting [MC] incision), and (3) extending from the LA towards the dorsum at a 45° angle, between the parallel lines of myomeres (muscle-sparing [MS] incision). A Juvenile Salmon Acoustic Telemetry System acoustic transmitter (0.44 g in air) and a passive integrated transponder tag (0.10 g in air) were implanted into each fish (total N = 936 fish). The fish were held at 12°C or 20°C and were examined weekly for 98 d. The progression of healing among incision locations and the variability in transmitter loss made it difficult to identify one incision location as the best choice. The LA incisions had a much smaller wound extent (area of visible subepidermal tissue) than MC and MS incisions during the first 28 d of the study. In both temperature treatments, apposition of incisions through day 14 was better for LA incisions than for MC and MS incisions. However, MC and MS incisions were less likely than LA incisions to reopen over time and thus were less likely to allow transmitter loss through the incision.

  5. Comparison of two different labial salivary gland biopsy incision techniques: A randomized clinical trial

    PubMed Central

    Ati775 i?kler, Mert; Ergun, Sertan; Ofluo?lu, Duygu; Tanyeri775 i?, Hakk?

    2013-01-01

    Objectives: To compare the reliability of two different labial salivary gland biopsy (LSGB) incision techniques (vertical versus horizontal incision techniques) and to report the related complications and discomfort. Study Design: 163 patients who underwent LSGB were included in this study. Patients were randomly divided as vertical incision group (n=81) and horizontal incision group (n=82). Demographic and clinical information of each patient were recorded. A questionnaire was prepared and applied together with Visual Analog Scale (VAS) on the subjects verbally at the 7th day, postoperatively. Intraoperative, short- term and delayed complications were evaluated. Results: The mean age of patients (117 female, 46 male) was 47.3 years (range 19-79 years). Vertical incision technique was associated with less pain (p<0.001), less swelling (p<0.05), less scar formation (p<0.05) and less difficulty in eating (p<0.05) when compared with horizontal incision technique. No statistically significant differences were observed between the 2 groups in terms of hematoma, parasthesia and speech difficulty (p>0.05). Additionally, two subjects in the horizontal incision group revealed permanent paresthesia during the follow-up period of two years. Conclusions: This prospective study demonstrated that the subjects in the vertical incision group had less complication rates and discomfort after labial salivary gland procedure than those in the horizontal incision group. Key words:Salivary gland, biopsy, incision. PMID:23986021

  6. Impact of channel incision on the hydraulics of flood flows: Examples from Polish Carpathian rivers

    NASA Astrophysics Data System (ADS)

    Wyżga, Bartłomiej; Zawiejska, Joanna; Radecki-Pawlik, Artur

    2016-11-01

    Channel deepening may result from channel incision or river metamorphosis changing a wide and shallow channel to a narrow and deep one. As only the first type of channel change leads to increased flow capacity of the channel, a lowering of water stage associated with a given discharge rather than a lowering of river bed should be used to identify channel incision. A lowering of minimum annual stage at gauging stations is typically used to assess the relative importance of channel incision along a river or within a particular region. Rivers of the Polish Carpathians incised by 0.5-3.8 m over the twentieth century, with the amount of incision being greater in their lower and middle courses than in the upper ones. Variability in the hydraulic importance of channel incision with increasing river size is analysed by comparing changes in the frequency of valley floor inundation at gauging stations located along the seventh-order Dunajec River. Despite a lower absolute amount of channel incision in the upper river course, here incision has increased channel conveyance and reduced the frequency of valley floor inundation considerably more than in the lower course. Hydraulic effects of channel incision depend also on lateral stability of an incising river. Low-energy rivers from the eastern part of the Polish Carpathians remained laterally stable during channel incision. This has resulted in substantial lowering of stages for low flood discharges and markedly smaller one for high-magnitude floods, whereas velocity of the flows conveyed over the highly elevated floodplains has decreased considerably. In high-energy rivers from the western part of the Polish Carpathians, alternation of incision and lateral channel migration has led to the formation of incised meander belts, with substantially lowered stages for all flood discharges and increased velocity of the flows conveyed over the newly-formed, low-lying floodplains.

  7. Progressive muscle relaxation, breathing exercises, and ABC relaxation theory.

    PubMed

    Matsumoto, M; Smith, J C

    2001-12-01

    This study compared the psychological effects of Progressive Muscle Relaxation (PMR) and breathing exercises. Forty-two students were divided randomly into two groups and taught PMR or breathing exercises. Both groups practiced for five weeks and were given the Smith Relaxation States Inventory before and after each session. As hypothesized, PMR practitioners displayed greater increments in relaxation states (R-States) Physical Relaxation and Disengagement, while breathing practitioners displayed higher levels of R-State Strength and Awareness. Slight differences emerged at Weeks 1 and 2; major differences emerged at Weeks 4 and 5. A delayed and potentially reinforcing aftereffect emerged for PMR only after five weeks of training--increased levels of Mental Quiet and Joy. Clinical and theoretical implications are discussed.

  8. Quasiparticle relaxation in superconducting nanostructures

    NASA Astrophysics Data System (ADS)

    Savich, Yahor; Glazman, Leonid; Kamenev, Alex

    2017-09-01

    We examine energy relaxation of nonequilibrium quasiparticles in "dirty" superconductors with the electron mean free path much shorter than the superconducting coherence length. Relaxation of low-energy nonequilibrium quasiparticles is dominated by phonon emission. We derive the corresponding collision integral and find the quasiparticle relaxation rate. The latter is sensitive to the breaking of time reversal symmetry (TRS) by a magnetic field (or magnetic impurities). As a concrete application of the developed theory, we address quasiparticle trapping by a vortex and a current-biased constriction. We show that trapping of hot quasiparticles may predominantly occur at distances from the vortex core, or the constriction, significantly exceeding the superconducting coherence length.

  9. Can Black Hole Relax Unitarily?

    NASA Astrophysics Data System (ADS)

    Solodukhin, S. N.

    2005-03-01

    We review the way the BTZ black hole relaxes back to thermal equilibrium after a small perturbation and how it is seen in the boundary (finite volume) CFT. The unitarity requires the relaxation to be quasi-periodic. It is preserved in the CFT but is not obvious in the case of the semiclassical black hole the relaxation of which is driven by complex quasi-normal modes. We discuss two ways of modifying the semiclassical black hole geometry to maintain unitarity: the (fractal) brick wall and the worm-hole modification. In the latter case the entropy comes out correctly as well.

  10. Stress relaxation in heterogeneous polymers

    NASA Astrophysics Data System (ADS)

    Witten, T. A.

    1992-05-01

    When heterogeneous polymers such as diblock copolymers form a microdomain phase, an imposed strain gives rise to stress from two sources, and several mechanisms of stress relaxation. The release of stress by disentanglement is strongly influenced by the effective confinement of the junction points to the domain boundaries and by the stretching of the chains. Using accepted notions of entangled chain kinetics, it is argued that the relaxation time for sliding stress is exponential in the chainlength to the 7/9 power. A method for calculating the frequency-dependent dynamic modulus is sketched. Despite the slow relaxation implied by these mechanisms, it appears possible to create domains of high energy.

  11. Single-incision laparoscopic surgery - current status and controversies

    PubMed Central

    Rao, Prashanth P; Rao, Pradeep P; Bhagwat, Sonali

    2011-01-01

    Scarless surgery is the Holy Grail of surgery and the very raison d’etre of Minimal Access Surgery was the reduction of scars and thereby pain and suffering of the patients. The work of Muhe and Mouret in the late 80s, paved the way for mainstream laparoscopic procedures and it rapidly became the method of choice for many intra-abdominal procedures. Single-incision laparoscopic surgery is a very exciting new modality in the field of minimal access surgery which works for further reducing the scars of standard laparoscopy and towards scarless surgery. Natural orifice translumenal endoscopic surgery (NOTES) was developed for scarless surgery, but did not gain popularity due to a variety of reasons. NOTES stands for natural orifice translumenal endoscopic surgery, a term coined by a consortium in 2005. NOTES remains a research technique with only a few clinical cases having been reported. The lack of success of NOTES seems to have spurred on the interest in single-incision laparoscopy as an eminently doable technique in the present with minimum visible scarring, rendering a ‘scarless’ effect. Laparo-endoscopic single-site surgery (LESS) is, a term coined by a multidisciplinary consortium in 2008 for single-incision laparoscopic surgery. These are complementary technologies with similar difficulties of access, lack of triangulation and inadequate instrumentation as of date. LESS seems to offer an advantage to surgeons with its familiar field of view and instruments similar to those used in conventional laparoscopy. LESS remains a evolving special technique used successfully in many a centre, but with a significant way to go before it becomes mainstream. It currently stands between standard laparoscopy and NOTES in the armamentarium of minimal access surgery. This article outlines the development of LESS giving an overview of all the techniques and devices available and likely to be available in the future. PMID:21197236

  12. Effect of the gamma knife treatment on the trigeminal nerve root in Chinese patients with primary trigeminal neuralgia.

    PubMed

    Song, Zhi-Xiu; Qian, Wei; Wu, Yu-Quan; Sun, Fang-Jie; Fei, Jun; Huang, Run-Sheng; Fang, Jing-Yu; Wu, Cai-Zhen; An, You-Ming; Wang, Daxin; Yang, Jun

    2014-01-01

    To understand the mechanism of the gamma knife treating the trigeminal neuralgia. Using the MASEP-SRRS type gamma knife treatment system, 140 Chinese patients with trigeminal neuralgia (NT) were treated in our hospital from 2002 to 2010, in which the pain relief rate reached 95% and recurrence rate was 3% only. We investigated the effect of the gamma knife treatment on the trigeminal nerve root in 20 Chinese patients with primary trigeminal neuralgia by the magnetic resonance imager (MRI) observation. 1) The cross-sectional area of trigeminal nerve root became smaller and MRI signals were lower in the treatment side than those in the non-treatment side after the gamma knife treatment of primary trigeminal neuralgia; 2) in the treatment side, the cross-sectional area of the trigeminal nerve root decreased significantly after the gamma knife treatment; 3) there was good correlation between the clinical improvement and the MRI findings; and 4) the straight distance between the trigeminal nerve root and the brainstem did not change after the gamma knife treatment. The pain relief induced the gamma knife radiosurgery might be related with the atrophy of the trigeminal nerve root in Chinese patients with primary trigeminal neuralgia.

  13. Review of single incision laparoscopic surgery in colorectal surgery

    PubMed Central

    Madhoun, Nisreen; Keller, Deborah S; Haas, Eric M

    2015-01-01

    As surgical techniques continue to move towards less invasive techniques, single incision laparoscopic surgery (SILS), a hybrid between traditional multiport laparoscopy and natural orifice transluminal endoscopic surgery, was introduced to further the enhanced outcomes of multiport laparoscopy. The safety and feasibility of SILS for both benign and malignant colorectal disease has been proven. SILS provides the potential for improved cosmesis, postoperative pain, recovery time, and quality of life at the drawback of higher technical skill required. In this article, we review the history, describe the available technology and techniques, and evaluate the benefits and limitations of SILS for colorectal surgery in the published literature. PMID:26478673

  14. Wound construction in manual small incision cataract surgery

    PubMed Central

    Haldipurkar, S S; Shikari, Hasanain T; Gokhale, Vishwanath

    2009-01-01

    The basis of manual small incision cataract surgery is the tunnel construction for entry to the anterior chamber. The parameters important for the structural integrity of the tunnel are the self-sealing property of the tunnel, the location of the wound on the sclera with respect to the limbus, and the shape of the wound. Cataract surgery has gone beyond just being a means to get the lens out of the eye. Postoperative astigmatism plays an important role in the evaluation of final outcome of surgery. Astigmatic consideration, hence, forms an integral part of incisional considerations prior to surgery. PMID:19075401

  15. Single incision laparoscopic cholecystectomy: Less scar, less pain

    PubMed Central

    Tyagi, Shantanu; Sinha, Rajeev; Tyagi, Aarti

    2017-01-01

    CONTEXT AND AIMS: Our study aims to evaluate the post-operative pain and cosmesis of single-incision laparoscopic cholecystectomy (SILC) in comparison with the standard, 3-port laparoscopic cholecystectomy (SLC) with respect to the length of incision, cosmetic scores, post-operative pain scores and duration of hospital stay. SETTINGS AND DESIGN: This comparative randomised study was conducted in a tertiary care centre teaching hospital between September 2012 and 2014. One hundred and fifty consecutive patients, who qualified as per inclusion criteria, were included in the study. SUBJECTS AND METHODS: Seventy-five patients were included in the SLC arm and 75 in the SILC arm. SILC procedure was carried out as transumbilical multiport technique and SLC as 3-port technique utilizing - 5, 5, 10 mm ports. STATISTICAL ANALYSIS USED: The data for the primary observations (post-operative pain scores, cosmetic score and incision length) and secondary observation (post-operative hospital stay) were noted. Weighted mean difference was used for calculation of quantitative variables, and odds ratios were used for pooling qualitative variables. RESULTS: Pain scores at 4 and 24 h were significantly better for SILC arm than SLC arm (at 4 h - 4.84 ± 0.95 vs. 6.17 ± 0.98, P < 0.05 and at 24 h - 3.84 ± 0.96 vs. 5.17 ± 0.09, P < 0.05). Length of incision was significantly smaller (SILC - 2.631 ± 0.44 cm vs. SLC - 5.11 ± 0.44 cm), P < 0.05 and cosmetic score was significantly better in SILC arm (6.25 ± 1.24) than SLC arm (4.71 ± 1.04), P < 0.05. Difference between the hospital stay is insignificant for two arms SILC (2.12 ± 0.34) and SLC (2.13 ± 0.35), P > 0.05. DISCUSSION: Significant difference was found in duration and intensity of pain between two procedures at 4 and 24 h. Cosmesis was significantly better in SILC than SLC group, the sample size in our study was small to arrive at a definite conclusion. The procedure can be selectively and judiciously performed by surgeons

  16. Canyon incision, volcanic fill, and re-incision rates in southwest Peru: proxies for quantifying uplift in the Central Andes

    NASA Astrophysics Data System (ADS)

    Thouret, Jean-Claude; Gunnell, Yanni; de La Rupelle, Aude

    2010-05-01

    Using zircon and apatite fission tracks and apatite (U-Th)/He to constrain 26 rock cooling histories of Cretaceous diorites and 40Ar-39Ar to date 45 Neogene ignimbrites and lavas, we have estimated incision and topographic uplift rates of the Western Cordillera in southwest Peru. Rock cooling patterns confirm that continental denudation declined rapidly during the early Cenozoic. Topographic paleoelevations provided by 24.5 Ma forearc marine sediments now occurring at 1.8 km a.s.l. indicate that the Andean orogenic plateau did not begin to rise before Miocene time. A suite of marker horizons consisting of Huaylillas ignimbrite (14.3-12.7 Ma) on the plateau, and of Sencca ignimbrite (3.8 Ma) and Barroso lavas (2.27 Ma) near the Rio Cotahuasi and Rio Ocoña valley floors, respectively, have helped to bracket accelerated uplift between 13 Ma and 3.8-2.27 Ma. In-canyon (U-Th)/He bedrock cooling ages decrease upstream from ~13 Ma to 2-4 Ma, implying that uplift-driven valley incision began after 14 Ma and that downcutting was neither steady nor uniform along the 209 km-long canyon system. Whereas ~9 Ma Caraveli ignimbrites filled broad, shallow valleys, V-shaped downcutting occurred after 9-6 Ma. Argon-dated in-canyon lava flows and ignimbrites reveal three pulses of bedrock incision: 8.8-5.8 Ma, 5.8-3.6 Ma, 3.6-1.36 Ma, followed by post-1.36 Ma re-incision into unconsolidated valley fill. Accordingly, ample variations belie the 14 Myr-averaged incision rate of 170 m Myr-1: 130-190 m Myr-1 between 13 and 9 Ma, rising to 250-400 m/Myr-1 between 9 and 3.8 Ma and to >1000 m Myr-1 of reincision after 1.36 Ma. Rapid bedrock incision ended before 3.76 Ma in the upper, and before 2.27 Ma in the lower canyon reaches. The 3.76 to 1.36 Ma pyroclastic and mass-flow deposits filled the valley to ~75% and ~60% of its height in its upper and lower reaches, respectively. Post-1.36 Ma re-incision removed 75% of these deposits, thus exhuming most of the bedrock paleocanyon. The upper

  17. [Effect of Small Knife Needle on β-enorpin and Enkehalin Contents of Tansverse Process Syndrome of the Third Vertebra].

    PubMed

    Liu, Nai-gang; Guo, Chang-qing; Sun, Hong-mei; Li, Xiao-hong; Wu, Hai-xia; Xu, Hong

    2016-04-01

    To explore the analgesic mechanism of small knife needle for treating transverse process syndrome of the third vertebra (TPSTV) by observing peripheral and central changesof β-endorphin (β-EP) and enkephalin (ENK) contents. Totally 30 Japanese white big-ear rabbits of clean grade were divided into 5 groups according to random digit table, i.e., the normal control group, the model group, the small knife needle group, the electroacupunture (EA) group, and the small knife needle plus EA group, 6 in each group. The TPSTV model was established by inserting a piece of gelatin sponge into the left transverse process of 3rd lumbar vertebrae. Rabbits in the small knife needlegroup were intervened by small knife needle. Those in the EA group were intervened by EA at bilateralWeizhong (BL40). Those in the small knife needle plus EA group were intervened by small knife needleand EA at bilateral Weizhong (BL40). Contents of β-EP and ENK in plasma, muscle, spinal cord, and hypothalamus were determined after sample collection at day 28 after modeling. Compared with the normal control group, contents of β-EP and ENK in plasma and muscle increased significantly, and contents of β-EP and ENK in spinal cord and hypothalamus decreased significantly in the model group (P < 0.05, P < 0.01). Contents of β-EP and ENK approximated normal levels in the three treatment groups after respective treatment. Compared with the model group, the content of β-EP in muscle decreased, and contents of β-EP and ENK in hypothalamus increased in the three treatment groups after respective treatment (P < 0.05). There were no significant difference among the three treatment groups (P > 0.05). Small knife needle treatment and EA had benign regulation on peripheral and central β-EP and ENK in TPSTV rabbits. Small knife needle treatment showed better effect than that of EA.

  18. Whole-procedure clinical accuracy of Gamma Knife treatments of large lesionsa).

    PubMed

    Ma, Lijun; Chuang, Cynthia; Descovich, Martina; Petti, Paula; Smith, Vernon; Verhey, Lynn

    2008-11-01

    The mechanical accuracy of Gamma Knife radiosurgery based on single-isocenter measurement has been established to within 0.3mm. However, the full delivery accuracy for Gamma Knife treatments of large lesions has only been estimated via the quadrature-sum analysis. In this study, the authors directly measured the whole-procedure accuracy for Gamma Knife treatments of large lesions to examine the validity of such estimation. The measurements were conducted on a head-phantom simulating the whole treatment procedure that included frame placement, computed tomography imaging, treatment planning, and treatment delivery. The results of the measurements were compared with the dose calculations from the treatment planning system. Average agreements of 0.1-1.6mm for the isodose lines ranging from 25% to 90% of the maximum dose were found despite potentially large contributing uncertainties such as 3-mm imaging resolution, 2-mm dose grid size, 1-mm frame registration, multi-isocenter deliveries, etc. The results of our measurements were found to be significantly smaller (>50%) than the calculated value based on the quadrature-sum analysis. In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain. © 2008 American Association of Physicists in Medicine.

  19. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    SciTech Connect

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao

    2016-01-28

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke’s tabulated data.

  20. Implementation of a quantitative Foucault knife-edge method by means of isophotometry

    NASA Astrophysics Data System (ADS)

    Zhevlakov, A. P.; Zatsepina, M. E.; Kirillovskii, V. K.

    2014-06-01

    Detailed description of stages of computer processing of the shadowgrams during implementation of a modern quantitative Foucault knife-edge method is presented. The map of wave-front aberrations introduced by errors of an optical surface or a system, along with the results of calculation of the set of required characteristics of image quality, are shown.

  1. Development of an air-knife system for highly reproducible fabrication of polydimethylsiloxane microstencils

    NASA Astrophysics Data System (ADS)

    Choi, Jin Ho; Kim, Gyu Man

    2015-08-01

    In this study, an air-knife system was developed for the automated fabrication of polymer microstencils with microscale perforated patterns. Blowing compressed N2 gas through the air knife provided a uniform laminar gas flow of high intensity suitable for perforating holes in the stencil. The polydimethylsiloxane (PDMS) stencil was replicated from a master mold prepared by photolithography. When the prepolymer of PDMS was spin-coated onto the master mold, a thin layer of the prepolymer remained on top of the master's structure and consequently prevented the formation of the perforated patterns. This residual layer was easily removed by the presented air knife. The air-knife system controlled the flow rate of N2 gas and the conveying speed of the master mold; therefore, the system possessed high reproducibility compared to manual gas blowing. Its use reduced the fabrication time for perforated biocompatible polymer microstencils, allowing for their mass production via an automated system. The validity of this suggested method was proven through experiments and was evaluated by application in various fields.

  2. Quantitative phase tomography by using x-ray microscope with Foucault knife-edge scanning filter

    NASA Astrophysics Data System (ADS)

    Watanabe, Norio; Tsuburaya, Yuji; Shimada, Akihiro; Aoki, Sadao

    2016-01-01

    Quantitative phase tomography was evaluated by using a differential phase microscope with a Foucault knife-edge scanning filter. A 3D x-ray phase image of polystyrene beads was obtained at 5.4 keV. The reconstructed refractive index was fairly good agreement with the Henke's tabulated data.

  3. The Effects of Swedish Knife Model on Students' Understanding of the Digestive System

    ERIC Educational Resources Information Center

    Cerrah Ozsevgec, Lale; Artun, Huseyin; Unal, Melike

    2012-01-01

    This study was designed to examine the effect of Swedish Knife Model on students' understanding of digestive system. A simple experimental design (pretest-treatment-posttest) was used in the study and internal comparison of the results of the one group was made. The sample consisted of 40 7th grade Turkish students whose ages range from 13 to 15.…

  4. Whole-procedure clinical accuracy of gamma knife treatments of large lesions.

    PubMed

    Ma, Lijun; Chuang, Cynthia; Descovich, Martina; Petti, Paula; Smith, Vernon; Verhey, Lynn

    2008-11-01

    The mechanical accuracy of Gamma Knife radiosurgery based on single-isocenter measurement has been established to within 0.3 mm. However, the full delivery accuracy for Gamma Knife treatments of large lesions has only been estimated via the quadrature-sum analysis. In this study, the authors directly measured the whole-procedure accuracy for Gamma Knife treatments of large lesions to examine the validity of such estimation. The measurements were conducted on a head-phantom simulating the whole treatment procedure that included frame placement, computed tomography imaging, treatment planning, and treatment delivery. The results of the measurements were compared with the dose calculations from the treatment planning system. Average agreements of 0.1-1.6 mm for the isodose lines ranging from 25% to 90% of the maximum dose were found despite potentially large contributing uncertainties such as 3-mm imaging resolution, 2-mm dose grid size, 1-mm frame registration, multi-isocenter deliveries, etc. The results of our measurements were found to be significantly smaller (>50%) than the calculated value based on the quadrature-sum analysis. In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain.

  5. 18. DETAIL OF COMBINATION HANDWASH SINK/KNIFE STERILIZER ON SPLITTERS' PLATFORM; ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. DETAIL OF COMBINATION HANDWASH SINK/KNIFE STERILIZER ON SPLITTERS' PLATFORM; KNIVES AND CLEAVERS WERE CLEANED FREQUENTLY BY DIPPING THEM INTO STEAM-HEATED WATER IN THE RECTANGULAR TANK; NOTE FOOT-OPERATED FAUCETS - Rath Packing Company, Beef Killing Building, Sycamore Street between Elm & Eighteenth Streets, Waterloo, Black Hawk County, IA

  6. The Effects of Swedish Knife Model on Students' Understanding of the Digestive System

    ERIC Educational Resources Information Center

    Cerrah Ozsevgec, Lale; Artun, Huseyin; Unal, Melike

    2012-01-01

    This study was designed to examine the effect of Swedish Knife Model on students' understanding of digestive system. A simple experimental design (pretest-treatment-posttest) was used in the study and internal comparison of the results of the one group was made. The sample consisted of 40 7th grade Turkish students whose ages range from 13 to 15.…

  7. Dose De-Escalation With Gamma Knife Radiosurgery in the Treatment of Choroidal Melanoma

    SciTech Connect

    Schirmer, Clemens M.; Chan, Michael; Mignano, John; Duker, Jay; Melhus, Christopher S.; Williams, Lloyd B.; Wu, Julian K.; Yao, Kevin C.

    2009-09-01

    Purpose: Single-fraction targeted radiation therapy delivered by the Leksell Gamma Knife system is a minimally invasive treatment option for choroidal melanoma that has been used as an alternative to enucleation, proton beam therapy, or brachytherapy. Previously reported Gamma Knife series involved the treatment of choroidal melanomas with a dose of 40 to 50 Gy at the tumor margin. We report our institutional experience using a significantly lower dose. Methods and Materials: Fourteen patients with choroidal melanoma were treated with the Leksell Gamma Knife at our institution over a 7-year period. The treatment and clinical data were analyzed in a retrospective fashion after a mean follow-up of 32.2 months. Results: The mean dose to the tumor margin was 22.2 {+-} 2.4 Gy (range, 20- 25 Gy). Mean treated tumor volume was 1.1 {+-} 1.2 cc. Local control was achieved in 13 cases (93%). In 1 patient both intraocular spread and distant metastatic disease developed after treatment. Visual function of the affected eye was preserved in 5 patients (36%) at latest follow-up, in 9 patients (64%) visual loss ensued. Mild to moderate radiation toxicity developed in 8 patients. Conclusions: Choroidal melanoma can be safely and effectively treated using Leksell Gamma Knife stereotactic radiosurgery with a marginal dose of less than 25 Gy.

  8. Effects of photoperiod and hypothalamic knife cuts on the timing of FSH surges in hamsters.

    PubMed

    Badura, L L; Sisk, C L; Nunez, A A

    1991-02-01

    The timing of the proestrous surge of follicle-stimulating hormone (FSH) was examined in female hamsters with hypothalamic knife cuts that prevented reproductive responses to photoperiod. All animals received either a horizontal knife cut aimed between the suprachiasmatic nuclei (SCN) and the paraventricular nuclei (PVN), or sham surgery, and were housed in long (16 h of light/24 h) or short (6 h of light/24 h) photoperiods. Following exposure to either photo-period for 11-12 weeks, a subset of the animals was fitted with an indwelling jugular cannula. Blood samples were taken hourly over a 24-h period and plasma levels of FSH were determined by RIA. Knife cuts placed ventral to or through the ventral portions of the PVN prevented short day-induced anestrus. On the day of proestrus, peak elevations of FSH in cycling animals with knife cuts in both photoperiods, as well as in sham-operated females in long days, occurred 4-5 h before lights out. In contrast, sham-operated anestrous females in short days showed peak elevations of FSH approximately 3-4 h after lights out. The present results support the view that neural connections between the SCN and the PVN mediate the effects of short days on reproductive physiology, including changes in the timing of the FSH surge.

  9. Chief Dull Knife Community Is Strengthening the Northern Cheyenne Language and Culture.

    ERIC Educational Resources Information Center

    Littlebear, Richard E.

    2003-01-01

    Language revitalization programs should focus on whether they want to teach the language, teach about the language, teach with the language, or teach the language for academic credit. A program at Chief Dull Knife College (Montana) teaches the Cheyenne language using the Total Physical Response method, which replicates the manner in which first…

  10. Endoscopic Submucosal Dissection Using a Novel Versatile Knife: An Animal Feasibility Study (with Video)

    PubMed Central

    Kwon, Chang-Il; Kim, Gwangil; Kim, Won Hee; Ko, Kwang Hyun; Hong, Sung Pyo; Jeong, Seok; Lee, Don Haeng

    2014-01-01

    Background/Aims In order to reduce the procedure time and the number of accessory changes during endoscopic submucosal dissection (ESD), we developed a novel versatile knife, which has the combined advantages of several conventional knives. The aim of this study was to compare the efficacy, safety, and histological quality of ESD performed using this novel versatile knife and a combination of several conventional knives. Methods This was an in vivo animal study comparing two different modalities of ESD in mini-pigs. Completion time of each resection was documented, and the resected specimens were retrieved and evaluated for completeness. To assess the quality control of the procedures and adverse events, detailed histopathological examinations were performed. Results A total of 18 specimens were dissected by ESD safely and easily (nine specimens using the new versatile knife; nine specimens by mixing conventional knives). All resections were completed as en bloc resections. There was no significant difference in procedure time between the 2 modalities (456 seconds vs. 355 seconds, p=0.258) and cutting speed (1.983 mm2/sec vs. 1.57 mm2/sec, p=1.000). The rate of adverse events and histological quality did not statistically differ between the modalities. Conclusions ESD with a versatile knife appeared to be an easy, safe, and technically efficient method. PMID:25505721

  11. Past, Present and Future. Dull Knife Memorial College (Indian Action Program Inc.).

    ERIC Educational Resources Information Center

    1978

    Five vocational training programs as well as academic coursework are offered on the Northern Cheyenne Reservation by Dull Knife Memorial College. Established and operated by the Northern Cheyenne, and located in Lame Deer, Montana, the college was chartered by a tribal ordinance in 1975. Approximately 75 trainees are currently involved in the…

  12. Knife River: Early Village Life on the Plains. Teaching with Historic Places.

    ERIC Educational Resources Information Center

    Metcalf, Fay

    This document, from the lesson plan series, "Teaching with Historic Places," examines the Native Americans who lived on the plains along the Knife River in what is now North Dakota. Following an introductory section, the document sets out student objectives, teaching activities, readings, and illustrations. The teaching activity…

  13. Whole-procedure clinical accuracy of Gamma Knife treatments of large lesions

    SciTech Connect

    Ma Lijun; Chuang, Cynthia; Descovich, Martina; Petti, Paula; Smith, Vernon; Verhey, Lynn

    2008-11-15

    The mechanical accuracy of Gamma Knife radiosurgery based on single-isocenter measurement has been established to within 0.3 mm. However, the full delivery accuracy for Gamma Knife treatments of large lesions has only been estimated via the quadrature-sum analysis. In this study, the authors directly measured the whole-procedure accuracy for Gamma Knife treatments of large lesions to examine the validity of such estimation. The measurements were conducted on a head-phantom simulating the whole treatment procedure that included frame placement, computed tomography imaging, treatment planning, and treatment delivery. The results of the measurements were compared with the dose calculations from the treatment planning system. Average agreements of 0.1-1.6 mm for the isodose lines ranging from 25% to 90% of the maximum dose were found despite potentially large contributing uncertainties such as 3-mm imaging resolution, 2-mm dose grid size, 1-mm frame registration, multi-isocenter deliveries, etc. The results of our measurements were found to be significantly smaller (>50%) than the calculated value based on the quadrature-sum analysis. In conclusion, Gamma Knife treatments of large lesions can be delivered much more accurately than predicted from the quadrature-sum analysis of major sources of uncertainties from each step of the delivery chain.

  14. Chief Dull Knife Community Is Strengthening the Northern Cheyenne Language and Culture.

    ERIC Educational Resources Information Center

    Littlebear, Richard E.

    2003-01-01

    Language revitalization programs should focus on whether they want to teach the language, teach about the language, teach with the language, or teach the language for academic credit. A program at Chief Dull Knife College (Montana) teaches the Cheyenne language using the Total Physical Response method, which replicates the manner in which first…

  15. CT-Guided Fiducial Placement for CyberKnife Stereotactic Radiosurgery: An Initial Experience

    SciTech Connect

    Sotiropoulou, Evangelia; Stathochristopoulou, Irene; Stathopoulos, Konstantinos; Verigos, Kosmas; Salvaras, Nikolaos; Thanos, Loukas

    2010-06-15

    CyberKnife frameless image-guided radiosurgery has become a widely used system for parenchymal extracranial lesions. Gold fiducials are required for the planning and aiming of CyberKnife therapy. We report our initial experience and describe the technique of positioning tumor markers, under CT guidance. We conducted a retrospective review of 105 patients who were referred for CyberKnife stereotactic radiosurgery at Iatropolis CyberKnife Center in Athens. All patients underwent percutaneous fiducial placement via CT guidance. At the desired location, the 18-G needle was advanced into or near the tumor. Data collected included number and locations of fiducials placed and complications experienced to date. One hundred five patients underwent fiducial placement under CT guidance and a total number of 319 gold seeds were implanted. We experienced one episode of pneumothorax that required drainage, one mild pneumothorax, and three episodes of perifocal pulmonary hemorrhage. In conclusion, fiducial implantation under CT guidance appears to be a safe and efficient procedure, as long as it is performed by an experienced interventional radiologist.

  16. Extracranial Facial Nerve Schwannoma Treated by Hypo-fractionated CyberKnife Radiosurgery

    PubMed Central

    Miyazaki, Shinichiro; Hori, Tomokatsu

    2016-01-01

    Facial nerve schwannoma is a rare intracranial tumor. Treatment for this benign tumor has been controversial. Here, we report a case of extracranial facial nerve schwannoma treated successfully by hypo-fractionated CyberKnife (Accuray, Sunnyvale, CA) radiosurgery and discuss the efficacy of this treatment. A 34-year-old female noticed a swelling in her right mastoid process. The lesion enlarged over a seven-month period, and she experienced facial spasm on the right side. She was diagnosed with a facial schwannoma via a magnetic resonance imaging (MRI) scan of the head and neck and was told to wait until the facial nerve palsy subsides. She was referred to our hospital for radiation therapy. We planned a fractionated CyberKnife radiosurgery for three consecutive days. After CyberKnife radiosurgery, the mass in the right parotid gradually decreased in size, and the facial nerve palsy disappeared. At her eight-month follow-up, her facial spasm had completely disappeared. There has been no recurrence and the facial nerve function has been normal. We successfully demonstrated the efficacy of CyberKnife radiosurgery as an alternative treatment that also preserves neurofunction for facial nerve schwannomas. PMID:27774363

  17. Stereotactic ablative radiotherapy with CyberKnife for advanced thymic carcinoma: a case report.

    PubMed

    Fan, C Y; Huang, W Y; Jen, Y M; Lin, M J; Lin, K T

    2015-10-01

    Thymic carcinoma is a rare but lethal mediastinal cancer. The optimal treatment for advanced thymic carcinoma is not yet established. This report is the first known of stereotactic ablative radiotherapy (sabr) with CyberKnife (Accuray, Sunnyvale, CA, U.S.A.) as definitive therapy for thymic carcinoma. The patient, a 70-year-old woman with thymic carcinoma, invasion into neighboring organs, and pleural metastases-underwent CyberKnife sabr at 40 Gy in 5 fractions for two lesions, one in the thymus and one in the right paraspinal pleura. After 61 months of observation, a partial response was observed in the irradiated fields. However, disease progression in the non-irradiated pleura was noted. The patient underwent salvage CyberKnife sabr for the four initially nonirradiated pleural lesions. Computed tomography images obtained 10 months after the salvage therapy revealed a partial response. The patient is living, with progression-free irradiated lesions and no radiation-related toxicity. CyberKnife sabr is feasible for patients who are unable to undergo either surgery or conventionally fractionated radiation therapy.

  18. Extracranial Facial Nerve Schwannoma Treated by Hypo-fractionated CyberKnife Radiosurgery.

    PubMed

    Sasaki, Ayaka; Miyazaki, Shinichiro; Hori, Tomokatsu

    2016-09-21

    Facial nerve schwannoma is a rare intracranial tumor. Treatment for this benign tumor has been controversial. Here, we report a case of extracranial facial nerve schwannoma treated successfully by hypo-fractionated CyberKnife (Accuray, Sunnyvale, CA) radiosurgery and discuss the efficacy of this treatment. A 34-year-old female noticed a swelling in her right mastoid process. The lesion enlarged over a seven-month period, and she experienced facial spasm on the right side. She was diagnosed with a facial schwannoma via a magnetic resonance imaging (MRI) scan of the head and neck and was told to wait until the facial nerve palsy subsides. She was referred to our hospital for radiation therapy. We planned a fractionated CyberKnife radiosurgery for three consecutive days. After CyberKnife radiosurgery, the mass in the right parotid gradually decreased in size, and the facial nerve palsy disappeared. At her eight-month follow-up, her facial spasm had completely disappeared. There has been no recurrence and the facial nerve function has been normal. We successfully demonstrated the efficacy of CyberKnife radiosurgery as an alternative treatment that also preserves neurofunction for facial nerve schwannomas.

  19. Sphincterotomy by triple lumen needle knife using guide wire in patients with Billroth II gastrectomy.

    PubMed

    Park, Su Bum; Kim, Hyung Wook; Kang, Dae Hwan; Choi, Cheol Woong; Yoon, Ki Tae; Cho, Mong; Song, Byeong Jun

    2013-12-28

    To investigate the usefulness of a guide wire and triple lumen needle knife for removing stones in Billroth II (B-II) gastrectomy patients. Endoscopic sphincterotomy in patients with B-II gastrectomy is challenging. We used a new guide wire technique involving sphincterotomy by triple lumen needle knife through a forward-viewing endoscopy. This technique was performed in nine patients between August 2010 and June 2012. Sphincterotomy as described above was performed. Adequate sphincterotomy, successful stone removal, and complications were investigated prospectively. Sphincterotomy by triple lumen needle knife using guide wire was successful in all nine patients. Sphincterotomy started towards the 4-5 o'clock direction and continued to the upper margin of the papillary roof. Complete stone removal in one session was achieved in all patients. There were no procedure related complications, such as bleeding, pancreatitis, or perforation. In patients with B-II gastrectomy, guide wire using sphincterotomy by triple lumen needle knife through a forward-viewing endoscopy seems to be an effective and safe procedure for the removal of common bile duct stones.

  20. Stereotactic diffusion tensor imaging tractography for Gamma Knife radiosurgery.

    PubMed

    Gavin, Cormac G; Ian Sabin, H

    2016-12-01

    OBJECTIVE The integration of modern neuroimaging into treatment planning has increased the therapeutic potential and safety of stereotactic radiosurgery. The authors report their method of integrating stereotactic diffusion tensor imaging (DTI) tractography into conventional treatment planning for Gamma Knife radiosurgery (GKRS). The aim of this study was to demonstrate the feasibility of this technique and to address some of the technical limitations of previously reported techniques. METHODS Twenty patients who underwent GKRS composed the study cohort. They consisted of 1 initial test case (a patient with a vestibular schwannoma), 5 patients with arteriovenous malformations, 9 patients with cerebral metastases, 1 patient with parasagittal meningioma, and 4 patients with vestibular schwannoma. DT images were obtained at the time of standard GKRS protocol MRI (T1 and T2 weighted) for treatment, with the patient's head secured by a Leksell stereotactic frame. All studies were performed using a 1.5-T magnet with a single-channel head coil. DTI was performed with diffusion gradients in 32 directions and coregistered with the volumetric T1-weighted study. DTI postprocessing by means of commercially available software allowed tensor computation and the creation of directionally encoded color-, apparent diffusion coefficient-, and fractional anisotropy-mapped sequences. In addition, the software allowed visualized critical tracts to be exported as a structural volume and integrated into GammaPlan as an "organ at risk" during shot planning. Combined images were transferred to GammaPlan and integrated into treatment planning. RESULTS Stereotactic DT images were successfully acquired in all patients, with generation of correct directionally encoded color images. Tract generation with the software was straightforward and reproducible, particularly for axial tracts such as the optic radiation and the arcuate fasciculus. Corticospinal tract visualization was hampered by some

  1. Pulsed electron avalanche knife (PEAK) for intraocular surgery.

    PubMed

    Palanker, D V; Miller, J M; Marmor, M F; Sanislo, S R; Huie, P; Blumenkranz, M S

    2001-10-01

    To develop a better and more economical instrument for precise, tractionless, "cold" cutting during intraocular surgery. The use of highly localized electric fields rather than laser light as the means of tissue dissection was investigated. A high electric field at the tip of a fine wire can, like lasers, initiate plasma formation. Micrometer-length plasma streamers are generated when an insulated 25 micron (microm) wire, exposed to physiological medium at one end, is subjected to nanosecond electrical pulses between 1 and 8 kV in magnitude. The explosive evaporation of water in the vicinity of these streamers cuts soft tissue without heat deposition into surrounding material (cold cutting). Streamers of plasma and the dynamics of water evaporation were imaged using an inverted microscope and fast flash photography. Cutting effectiveness was evaluated on both polyacrylamide gels, on different tissues from excised bovine eyes, and in vivo on rabbit retina. Standard histology techniques were used to examine the tissue. Electric pulses with energies between 150 and 670 microJ produced plasma streamers in saline between 10 and 200 microm in length. Application of electric discharges to dense (10%) polyacrylamide gels resulted in fracturing of the gel without ejection of bulk material. In both dense and softer (6%) gels, layer by layer shaving was possible with pulse energy rather than number of pulses as the determinant of ultimate cutting depth. The instrument made precise partial or full-thickness cuts of retina, iris, lens, and lens capsule without any evidence of thermal damage. Because different tissues require distinct energies for dissection, tissue-selective cutting on complex structures can be performed if the appropriate pulse energies are used; for example, retina can be dissected without damage to the major retinal vessels. This instrument, called the Pulsed Electron Avalanche Knife (PEAK), can quickly and precisely cut intraocular tissues without traction

  2. Stress Relaxation of Interim Restoratives.

    DTIC Science & Technology

    1978-05-18

    unmodified zinc oxide- eugenol cement were more favorable than those of IRM and Cavit. The plastic behavior of gutta-percha temporary stopping precluded assessment of its relaxation at temperatures in excess of 22P C. (Author)

  3. Relaxation Pathways in Metallic Glasses

    NASA Astrophysics Data System (ADS)

    Gallino, Isabella; Busch, Ralf

    2017-09-01

    At temperatures below the glass transition temperature, physical properties of metallic glasses, such as density, viscosity, electrical resistivity or enthalpy, slowly evolve with time. This is the process of physical aging that occurs among all types of glasses and leads to structural changes at the microscopic level. Even though the relaxation pathways are ruled by thermodynamics as the glass attempts to re-attain thermodynamic equilibrium, they are steered by sluggish kinetics at the microscopic level. Understanding the structural and dynamic pathways of the relaxing glassy state is still one of the grand challenges in materials physics. We review some of the recent experimental advances made in understanding the nature of the relaxation phenomenon in metallic glasses and its implications to the macroscopic and microscopic properties changes of the relaxing glass.

  4. Relaxation labeling using modular operators

    SciTech Connect

    Duncan, J.S.; Frei, W.

    1983-01-01

    Probabilistic relaxation labeling has been shown to be useful in image processing, pattern recognition, and artificial intelligence. The approaches taken to date have been encumbered with computationally extensive summations which generally prevent real-time operation and/or easy hardware implementation. The authors present a new and unique approach to the relaxation labeling problem using modular, VLSI-oriented hierarchical complex operators. One of the fundamental concepts of this work is the representation of the probability distribution of the possible labels for a given object (pixel) as an ellipse, which may be summed with neighboring object's distribution ellipses, resulting in a new, relaxed label space. The mathematical development of the elliptical approach will be presented and compared to more classical approaches, and a hardware block diagram that shows the implementation of the relaxation scheme using vlsi chips will be presented. Finally, results will be shown which illustrate applications of the modular scheme, iteratively, to both edges and lines. 13 references.

  5. Relaxation behavior of glassy selenium

    NASA Astrophysics Data System (ADS)

    Svoboda, Roman; Pustková, Pavla; Málek, Jiří

    2007-05-01

    The dynamics of the glass transition of amorphous selenium was investigated by using differential scanning calorimeter. The heat capacity data were analyzed applying the phenomenological Tool Narayanaswamy Moynihan (TNM) model in order to describe the relaxation behavior of a-Se. The TNM parameters were evaluated by fitting the enthalpic cycles and also one isothermal experiment. Furthermore, peak-shift method and several other methods of evaluating the TNM parameters were applied to confirm the results of curve fitting. The results are compared with the other published enthalpy and viscosity data, volume and enthalpy relaxation are compared on account of our previous mercury dilatometry measurements. We found out that the pre-exponential factor A and the apparent activation energy Δh* of structural relaxation are similar for volume and enthalpy relaxation and Δh* is very close to the activation energy of viscous flow.

  6. Trochlear Nerve Schwannoma Treated with Gamma Knife after Excision: A Case Report and Review of the Literature.

    PubMed

    Inoue, Takuro; Shima, Ayako; Hirai, Hisao; Suzuki, Fumio; Matsuda, Masayuki

    2015-11-01

    Trochlear nerve schwannomas are extremely rare. We present a surgically excised case of trochlear nerve schwannoma followed by Gamma Knife (ELEKTA, Stockholm, Sweden) after histologic confirmation. A 52-year-old man presented with diplopia, gait disturbance, and sensory disturbance. Magnetic resonance imaging demonstrated a large cystic mass at ambient cistern on the right side. Subtotal excision followed by Gamma Knife surgery was undertaken. His neurologic symptoms disappeared with radiologic reduction in size at 15-month follow-up. Because Gamma Knife can manage trochlear nerve schwannomas well, surgical excision should be reserved for large ones and limited to subcapsular or subtotal removal with the expectation of possible recovery of neurologic dysfunction.

  7. Relaxation Dynamics in Heme Proteins.

    NASA Astrophysics Data System (ADS)

    Scholl, Reinhard Wilhelm

    A protein molecule possesses many conformational substates that are likely arranged in a hierarchy consisting of a number of tiers. A hierarchical organization of conformational substates is expected to give rise to a multitude of nonequilibrium relaxation phenomena. If the temperature is lowered, transitions between substates of higher tiers are frozen out, and relaxation processes characteristic of lower tiers will dominate the observational time scale. This thesis addresses the following questions: (i) What is the energy landscape of a protein? How does the landscape depend on the environment such as pH and viscosity, and how can it be connected to specific structural parts? (ii) What relaxation phenomena can be observed in a protein? Which are protein specific, and which occur in other proteins? How does the environment influence relaxations? (iii) What functional form best describes relaxation functions? (iv) Can we connect the motions to specific structural parts of the protein molecule, and are these motions important for the function of the protein?. To this purpose, relaxation processes after a pressure change are studied in carbonmonoxy (CO) heme proteins (myoglobin-CO, substrate-bound and substrate-free cytochrome P450cam-CO, chloroperoxidase-CO, horseradish peroxidase -CO) between 150 K and 250 K using FTIR spectroscopy to monitor the CO bound to the heme iron. Two types of p -relaxation experiments are performed: p-release (200 to ~eq40 MPa) and p-jump (~eq40 to 200 MPa) experiments. Most of the relaxations fall into one of three groups and are characterized by (i) nonexponential time dependence and non-Arrhenius temperature dependence (FIM1( nu), FIM1(Gamma)); (ii) exponential time dependence and non-Arrhenius temperature dependence (FIM0(A_{i}to A_{j})); exponential time dependence and Arrhenius temperature dependence (FIMX( nu)). The influence of pH is studied in myoglobin-CO and shown to have a strong influence on the substate population of the

  8. Anterior ilioinguinal incision for drainage of high-located perianal abscess.

    PubMed

    Peng, K-T; Hsieh, M-C; Hsu, W-H; Li, Y-Y; Yeh, C-H

    2013-08-01

    Most perianal abscesses originate from infected anal glands at the base of the anal crypts. Most abscesses below are usually drained through perianal incision and can be treated successfully. However, when perianal abscesses extend to the high intrapelvic cavity, it may be inadequate treatment through a single route incision through a perianal approach. The aim of this technical note is to show that combined anterior ilioinguinal and perianal incisions may provide optimal surgical field and multiple drainages. Here, we report a 56-year-old male patient with perianal-originating parapsoas abscesses. Residual abscess still remained after initial perianal incision and drainage after 1-month treatment. We presented combined anterior ilioinguinal and perianal incision technique methods for proper drainage in this complicated case. No recurrent or residual abscess remained after 2 weeks of operation. So, combined anterior ilioinguinal incision is feasible for high-located perianal abscess.

  9. A sine-wave-shaped skin incision for inserting deep-brain stimulators.

    PubMed

    Solmaz, Bilgehan; Tatarli, Necati; Ceylan, Davut; Bayri, Yaşar; Ziyal, M Ibrahim; Şeker, Aşkin

    2014-08-01

    The sine-wave-shaped skin incision is a technique that minimizes skin-related complications near burr hole caps after electrode placement for deep-brain stimulation (DBS). Between 2011 and 2013, 54 DBS electrodes were implanted in 27 consecutive patients with Parkinson's disease (PD), essential tremor, or dystonia. The sine-wave incision was used in 26 patients and conventional bilateral linear scalp incisions were used in one patient. None of the patients whose operations involved sine-wave-shaped incisions developed hardware-linked complications such as skin infection or skin erosion. The one patient who underwent conventional bilateral linear scalp incisions developed a skin infection. By preserving the vascular anatomy of the scalp and reducing skin tension at the wound site, the sine-wave-shaped incision promotes wound healing.

  10. MRI-based polymer gel dosimetry for validating plans with multiple matrices in Gamma Knife stereotactic radiosurgery.

    PubMed

    Gopishankar, N; Watanabe, Yoichi; Subbiah, Vivekanandhan

    2011-01-31

    One of treatment planning techniques with Leksell GammaPlan (LGP) for Gamma Knife stereotactic radiosurgery (GKSRS) uses multiple matrices with multiple dose prescriptions. Computational complexity increases when shots are placed in multiple matrices with different grid sizes. Hence, the experimental validation of LGP calculated dose distributions is needed for those cases. For the current study, we used BANG3 polymer gel contained in a head-sized glass bottle to simulate the entire treatment process of GKSRS. A treatment plan with three 18 mm shots and one 8 mm shot in separate matrices was created with LGP. The prescribed maximum dose was 8 Gy to three shots and 16 Gy to one of the 18 mm shots. The 3D dose distribution recorded in the gel dosimeter was read using a Siemens 3T MRI scanner. The scanning parameters of a CPMG pulse sequence with 32 equidistant echoes were as follows: TR = 7 s, echo step = 13.6 ms, field-of-view = 256 mm × 256 mm, and pixel size = 1 mm × 1 mm. Interleaved acquisition mode was used to obtain 15 to 45 2-mm-thick slices. Using a calibration relationship between absorbed dose and the spin-spin relaxation rate (R2), we converted R2 images to dose images. MATLAB-based in-house programs were used for R2 estimation and dose comparison. Gamma-index analysis for the 3D data showed gamma values less than unity for 86% of the voxels. Through this study we accomplished the first application of polymer gel dosimetry for a true comparison between measured 3D dose distributions and LGP calculations for plans using multiple matrices for multiple targets.

  11. SU-E-T-804: Verification of the BJR-25 Method of KQ Determination for CyberKnife Absolute Dosimetry

    SciTech Connect

    Gersh, J; Willett, B

    2015-06-15

    Purpose: Absolute calibration of the CyberKnife is performed using a 6cm-diameter cone defined at 80cm SAD. Since kQ is defined using PDD values determined using 10×10 cm fields at 100cm SSD, the PDD must be corrected in order to correctly apply the quality conversion factor. The accepted method is based on equivalent field-size conversions of PDD values using BJR25. Using the new InCise MLC system, the CK is capable of generating a rectangular field equivalent to 10×10 cm square field. In this study, a comparison is made between kQ values determined using the traditional BJR25 method and the MLC method introduced herein. Methods: First, kQ(BJR) is determined: a PDD is acquired using a 6cm circular field at 100cm SSD, its field size converted to an equivalent square, and PDD converted to a 10×10cm field using the appropriate BJR25 table. Maintaining a consistent setup, the collimator is changed, and the MLC method is used. Finally, kQ is determined using PDDs acquired with a 9.71×10.31cm at 100cm SSD. This field is produced by setting the field to a size of 7.77×8.25cm (since it is defined at 80cm SAD). An exact 10×10cm field since field size is relegated to increments of its leaf width (0.25cm). This comparison is made using an Exradin A1SL, IBA CC08, IBA CC13, and an Exradin A19. For each detector and collimator type, the beam injector was adjusted to give 5 different beam qualities; representing a range of clinical systems. Results: Averaging across all beam qualities, kQ(MLC) differed from kQ(BJR) by less than 0.15%. The difference between the values increased with detector volume. Conclusion: For CK users with standard cone collimators, the BJR25 method has been verified. For CK users the MLC system, a technique is described to determine kQ. Primary author is the President/Owner of Spectrum Medical Physics, LLC, a company which maintains contracts with Siemens Healthcare and Standard Imaging, Inc.

  12. Relaxation processes in Aeolian transport

    NASA Astrophysics Data System (ADS)

    Selmani, Houssem; Valance, Alexandre; Ould El Moctar, Ahmed; Dupont, Pascal; Zegadi, Rabah

    2017-06-01

    We investigate experimentally the relaxation process toward the equilibrium regime of saltation transport in the context of spatial inhomogeneous conditions. The relaxation length associated to this process is an important length in aeolian transport. This length stands for the distance needed for the particle flux to adapt to a change in flow conditions or in the boundary conditions at the bed. Predicting the value of this length under given conditions of transport remains an open and important issue. We conducted wind tunnel experiments to document the influence of the upstream particle flux and wind speed on the relaxation process toward the saturated transport state. In the absence of upstream particle flux, data show that the relaxation length is independent of the wind strength (except close to the threshold of transport). In contrast, in the case of a finite upstream flux, the relaxation length exhibits a clear increase with increasing air flow velocity. Moreover, in the latter the relaxation is clearly non-monotonic and presents an overshoot.

  13. Vacancy Relaxation in Cubic Crystals

    NASA Technical Reports Server (NTRS)

    Girifalco, L. A.; Weizer, V. G.

    1960-01-01

    The configuration of the atoms surrounding a vacancy in four face-centered cubic and three body-centered cubic metals has been computed, using a pairwise, central-force model in which the energy of interaction between two atoms was taken to have the form of a Morse function. Only radial relaxations were considered. The first and second nearest-neighbor relaxations for the face-centered systems were found to be: Pb (1.42,-0.43), Ni (2.14,-0.39), Cu(2.24,-0.40) and Ca (2.73,-0.41, expressed in percentages of normal distances. For the body-centered systems the relaxations out to the fourth nearest neighbors to the vacancy were: Fe (6.07,-2.12, -0.25, -), Ba (7.85, -2.70, 0.70, -0.33) and Na (10.80, -3.14, 3.43, -0.20). The positive signs indicate relaxation toward the vacancy and the negative signs indicate relaxation away from the vacancy. The energies of relaxation (eV) are: Pb (0.162), Ni (0.626), Cu (0.560), Ca (0.400), Fe (1.410), Ba (0.950) and Na (0.172).

  14. Leksell Gamma Knife radiosurgery of the jugulotympanic glomus tumor: long-term results.

    PubMed

    Liscak, Roman; Urgosik, Dusan; Chytka, Tomas; Simonova, Gabriela; Novotny, Josef; Vymazal, Josef; Guseynova, Khumar; Vladyka, Vilibald

    2014-12-01

    Glomus tumors usually display indolent behavior, and the effectiveness of radiation in stopping their growth can be assessed after long-term follow-up. Currently only midterm results of radiosurgery are available, so the authors included patients treated by Gamma Knife at least 10 years ago in this study to obtain a perspective of long-term results. During the period from 1992 to 2003, the Gamma Knife was used to treat 46 patients with glomus tumors. The age of the patients ranged from 21 to 79 years (median 56 years). Gamma Knife radiosurgery was the primary treatment in 17 patients (37%). Open surgery preceded radiosurgery in 46% of cases, embolization in 17%, and fractionated radiotherapy in 4%. The volume of the tumor ranged from 0.2 to 24.3 cm(3) (median 3.6 cm(3)). The minimal dose to the tumor margin ranged between 10 and 30 Gy (median 20 Gy). One patient was lost for follow-up after radiosurgery. Clinical follow-up was available in 45 patients and 44 patients were followed with MRI in a follow-up period that ranged from 12 to 217 months (median 118 months). Neurological deficits improved in 19 (42%) of 45 patients and deteriorated in 2 patients (4%). Tumor size decreased in 34 (77%) of 44 patients with imaging follow-up, while an increase in volume was observed in 1 patient (2%) 182 months after radiosurgery and Gamma Knife treatment was repeated. One patient underwent another Gamma Knife treatment for secondary induced meningioma close to the glomus tumor 98 months after initial radiosurgical treatment. Seven patients died 22-96 months after radiosurgery (median 48 months), all for unrelated reasons. Radiosurgery has proved to be a safe treatment with a low morbidity rate and a reliable long-term antiproliferative effect.

  15. Effect of CyberKnife stereotactic body radiation therapy for hepatocellular carcinoma on hepatic toxicity

    PubMed Central

    Liang, Ping; Huang, Cheng; Liang, Shi-Xiong; Li, Ye-Fei; Huang, Shang-Xiao; Lian, Zu-Ping; Liu, Jian-Min; Tang, Yang; Lu, Hai-Jie

    2016-01-01

    Objective To evaluate the safety of CyberKnife stereotactic body radiation therapy (SBRT) for hepatocellular carcinoma (HCC) patients and identify the treatment-related risk factors of hepatic toxicity. Materials and methods One hundred and four HCC patients treated with CyberKnife SBRT were included in this study between August 2009 and December 2012. The average dose of prescribed radiation was 42.81±4.78 Gy (28–55 Gy) with the average fraction size of 8–16 Gy to the planning target volume. The average fractions were 3.31±0.81 (2–6 fractions). Response rates were determined, and the Child–Pugh (CP) score and class following CyberKnife SBRT were obtained to evaluate hepatic toxicity. Results Seventeen patients experienced progression in CP class and 24 patients experienced CTCAE V. 4.0 grade 2–3 hepatic toxicity during the five-month follow-up period, while no patient experienced grade 4 liver toxicity. Multivariate analysis indicated that only V25 was an independent factor in grade 2–3 hepatic toxicity (P=0.029, <0.05). Radiation-induced hepatic toxicity (RIHT), defined as an increase of at least two points within three months following CyberKnife SBRT, occurred in 13 of the 104 patients (13/104, 12.5%), and only the normal liver tissue was found to be associated with RIHT (P=0.008, <0.05). Conclusion CyberKnife SBRT is a feasible and safe treatment for HCC with regard to hepatic toxicity, while V25 and normal liver volume may be an independent factor of grade 2–3 hepatic toxicity and RIHT, respectively. PMID:27920555

  16. A microcosting study of microsurgery, LINAC radiosurgery, and gamma knife radiosurgery in meningioma patients.

    PubMed

    Tan, Siok Swan; van Putten, Erik; Nijdam, Wideke M; Hanssens, Patrick; Beute, Guus N; Nowak, Peter J; Dirven, Clemens M; Hakkaart-van Roijen, Leona

    2011-01-01

    The aim of the present study is to determine and compare initial treatment costs of microsurgery, linear accelerator (LINAC) radiosurgery, and gamma knife radiosurgery in meningioma patients. Additionally, the follow-up costs in the first year after initial treatment were assessed. Cost analyses were performed at two neurosurgical departments in The Netherlands from the healthcare providers' perspective. A total of 59 patients were included, of whom 18 underwent microsurgery, 15 underwent LINAC radiosurgery, and 26 underwent gamma knife radiosurgery. A standardized microcosting methodology was employed to ensure that the identified cost differences would reflect only actual cost differences. Initial treatment costs, using equipment costs per fraction, were 12,288 for microsurgery, 1,547 for LINAC radiosurgery, and 2,412 for gamma knife radiosurgery. Higher initial treatment costs for microsurgery were predominantly due to inpatient stay (5,321) and indirect costs (4,350). LINAC and gamma knife radiosurgery were equally expensive when equipment was valued per treatment (2,198 and 2,412, respectively). Follow-up costs were slightly, but not significantly, higher for microsurgery compared with LINAC and gamma knife radiosurgery. Even though initial treatment costs were over five times higher for microsurgery compared with both radiosurgical treatments, our study gives indications that the relative cost difference may decrease when follow-up costs occurring during the first year after initial treatment are incorporated. This reinforces the need to consider follow-up costs after initial treatment when examining the relative costs of alternative treatments.

  17. A microcosting study of microsurgery, LINAC radiosurgery, and gamma knife radiosurgery in meningioma patients

    PubMed Central

    van Putten, Erik; Nijdam, Wideke M.; Hanssens, Patrick; Beute, Guus N.; Nowak, Peter J.; Dirven, Clemens M.; Hakkaart-van Roijen, Leona

    2010-01-01

    The aim of the present study is to determine and compare initial treatment costs of microsurgery, linear accelerator (LINAC) radiosurgery, and gamma knife radiosurgery in meningioma patients. Additionally, the follow-up costs in the first year after initial treatment were assessed. Cost analyses were performed at two neurosurgical departments in The Netherlands from the healthcare providers’ perspective. A total of 59 patients were included, of whom 18 underwent microsurgery, 15 underwent LINAC radiosurgery, and 26 underwent gamma knife radiosurgery. A standardized microcosting methodology was employed to ensure that the identified cost differences would reflect only actual cost differences. Initial treatment costs, using equipment costs per fraction, were €12,288 for microsurgery, €1,547 for LINAC radiosurgery, and €2,412 for gamma knife radiosurgery. Higher initial treatment costs for microsurgery were predominantly due to inpatient stay (€5,321) and indirect costs (€4,350). LINAC and gamma knife radiosurgery were equally expensive when equipment was valued per treatment (€2,198 and €2,412, respectively). Follow-up costs were slightly, but not significantly, higher for microsurgery compared with LINAC and gamma knife radiosurgery. Even though initial treatment costs were over five times higher for microsurgery compared with both radiosurgical treatments, our study gives indications that the relative cost difference may decrease when follow-up costs occurring during the first year after initial treatment are incorporated. This reinforces the need to consider follow-up costs after initial treatment when examining the relative costs of alternative treatments. PMID:20526795

  18. Comparative analyses of linac and Gamma Knife radiosurgery for trigeminal neuralgia treatments

    NASA Astrophysics Data System (ADS)

    Ma, L.; Kwok, Y.; Chin, L. S.; Yu, C.; Regine, W. F.

    2005-11-01

    Dedicated linac-based radiosurgery has been reported for trigeminal neuralgia treatments. In this study, we investigated the dose fall-off characteristics and setup error tolerance of linac-based radiosurgery as compared with standard Gamma Knife radiosurgery. In order to minimize the errors from different treatment planning calculations, consistent imaging registration, dose calculation and dose volume analysis methods were developed and implemented for both Gamma Knife and linac-based treatments. Intra-arc setup errors were incorporated into the treatment planning process of linac-based deliveries. The effects of intra-arc setup errors with increasing number of arcs were studied and benchmarked against Gamma Knife deliveries with and without plugging patterns. Our studies found equivalent dose fall-off properties between Gamma Knife and linac-based radiosurgery given a sufficient number of arcs (>7) and small intra-arc errors (<0.5 mm) were satisfied for linac-based deliveries. Increasing the number of arcs significantly decreased the variations in the dose fall-off curve at the low isodose region (e.g. from 40% to 10%) and also improved dose uniformity at the high isodose region (e.g. from 70% to 90%). As the number of arcs increased, the effects of intra-arc setup errors on the dose fall-off curves decreased. Increasing the number of arcs also reduced the integral dose to the distal normal brain tissues. In conclusion, linac-based radiosurgery produces equivalent dose fall-off characteristics to Gamma Knife radiosurgery with a high number of arcs. However, one must note the increased treatment time for a large number of arcs and isocentre accuracies.

  19. Use of cyanoacrylate glue for the closure of uterine incisions.

    PubMed

    Basaran, Mustafa; Vural, Mehmet; Irkorucu, Oktay; Gul, Mesut

    2009-01-01

    Closure of uterine incisions in a variety of gynecological procedures, specifically in myomectomy operations, is associated with significant hemorrhage. Excessive suturing to control bleeding may have negative effects on wound healing and might increase peritoneal adhesions. Moreover, difficulty of handling uterine tissue in laparoscopic procedures is not only a factor for suboptimal closure and inadequate control of bleeding but also a significant factor for surgeons for choosing laparotomy over laparoscopic approach. Cyanoacrylates are a group of molecules used as industrial adhesives. Newer cyanoacrylates are widely used in medicine. These agents are excellent biological adhesives due to strong adhesive action, hemostatic action, and antibacterial properties. Moreover, the presence of blood and tissue fluids enhances the activity of cyanoacrylates. In this study, 2-octyl cyanoacrylate, polypropylene, and polyglactin 910 sutures were compared in terms of adhesive strength, control of hemorrhage and postoperative intraabdominal adhesions in a rat model. Wound healing was excellent in all groups. Cyanoacrylates were associated with significantly lower total adhesion scores. This is the first report proposing the use of cyanoacrylates in gynecologic surgeries with supporting evidence for clinical use. Cyanoacrylates might be the first choice for the closure of uterine incisions and for the control of hemorrhage especially in laparoscopic procedures.

  20. Avoiding Facial Incisions with Midface Free Tissue Transfer

    PubMed Central

    Stalder, Mark W.; Sosin, Michael; Urbinelli, Leo J.; Mayo, James L.; Dorafshar, Amir H.; Hilaire, Hugo St.; Borsuk, Daniel E.

    2017-01-01

    Background: We have adopted an intraoral microsurgical anastomosis to the facial vessels to eliminate the need for any visible facial incisions. Methods: Cadaveric dissection was used to demonstrate accessibility of the facial artery and vein through an intraoral approach. Additionally, 5 patients underwent free tissue transfer for reconstruction of major defects of the midface through an intraoral, transmucosal approach, obviating the need for visible skin incisions. Results: The pathology included palatal defects due to mucoepidermoid carcinoma and ischemic necrosis from cocaine abuse, maxillary defects secondary to fibrous dysplasia and avascular necrosis from traumatic blast injury, and a residual posttraumatic bony deformity of the zygoma. Reconstructions were performed with a free ulnar forearm flap, a free vastus lateralis muscle flap, a deep circumflex iliac artery myoosseous flap, a free fibula flap, and a deep circumflex iliac artery osseous flap, respectively. The facial artery and vein were used as recipient vessels for microvascular anastomosis for all cases. Mean follow-up was 12.2 months. All free tissue transfers were successful, and each patient had a satisfactory aesthetic outcome with no associated facial scars. Conclusion: This technique can be employed during reconstruction of an array of bony or soft-tissue midface deficits with minimal morbidity. This small series effectively demonstrates the varied pathologies and tissue deficiencies that can be successfully reconstructed with free tissue transfer using an entirely intraoral approach to the recipient facial vessels, resulting in no visible scars on the face and an improvement in the overall aesthetic outcome. PMID:28280662

  1. Rapid incision of the Colorado River in Glen Canyon - insights from channel profiles, local incision rates, and modeling of lithologic controls

    USGS Publications Warehouse

    Cook, K.L.; Whipple, K.X.; Heimsath, A.M.; Hanks, T.C.

    2009-01-01

    The Colorado River system in southern Utah and northern Arizona is continuing to adjust to the baselevel fall responsible for the carving of the Grand Canyon. Estimates of bedrock incision rates in this area vary widely, hinting at the transient state of the Colorado and its tributaries. In conjunction with these data, we use longitudinal profiles of the Colorado and tributaries between Marble Canyon and Cataract Canyon to investigate the incision history of the Colorado in this region. We find that almost all of the tributaries in this region steepen as they enter the Colorado River. The consistent presence of oversteepened reaches with similar elevation drops in the lower section of these channels, and their coincidence within a corridor of high local relief along the Colorado, suggest that the tributaries are steepening in response to an episode of increased incision rate on the mainstem. This analysis makes testable predictions about spatial variations in incision rates; these predictions are consistent with existing rate estimates and can be used to guide further studies. We also present cosmogenic nuclide data from the Henry Mountains of southern Utah. We measured in situ 10Be concentrations on four gravel-covered strath surfaces elevated from 1 m to 110 m above Trachyte Creek. The surfaces yield exposure ages that range from approximately 2??5 ka to 267 ka and suggest incision rates that vary between 350 and 600 m/my. These incision rates are similar to other rates determined within the high-relief corridor. Available data thus support the interpretation that tributaries of the Colorado River upstream of the Grand Canyon are responding to a recent pulse of rapid incision on the Colorado. Numerical modeling of detachment-limited bedrock incision suggests that this incision pulse is likely related to the upstream-dipping lithologic boundary at the northern edge of the Kaibab upwarp. ?? 2009 John Wiley & Sons, Ltd.

  2. Paraglacial fluvial bedrock incision in postglacial landscapes: the NW Scottish Highlands

    NASA Astrophysics Data System (ADS)

    Whitbread, Katie; Jansen, John; Bishop, Paul; Fabel, Derek

    2010-05-01

    Glacial landscape forms are inherited by rivers following deglaciation. Hillslopes and valley floors configured by glacial erosion control the distribution of bedrock channels and potential sites for fluvial incision. The importance of 'stream power' parameters, channel slope and drainage area (discharge), in controlling the rate of incision is widely accepted, but the rate, timing and mechanisms of incision have yet to be quantified in these settings. The dual controls of glacially conditioned bedrock slopes and sediment supply set two of the key boundary conditions for temporally and spatially dynamic fluvial bedrock incision. Measurement of incision rates in these settings is key to understanding the influence of controls on fluvial erosion, and the role of the process in long-term evolution of deglaciated landscapes. In tectonically-passive, hard-rock terrains, such as the Scottish Highlands, incisional fluvial features such as bedrock channels, gorges and waterfalls are common on glacially carved valley steps. Here we report preliminary data on fluvial incision rates measured with cosmogenic 10Be. Our results confirm a postglacial age of bedrock straths in the NW Scottish Highlands and indicate a vertical incision rate of 0.3 mm/yr into resistant quartzites. Further work will explore erosion mechanisms and rates of incision across the Scottish Highlands, and assess controls on fluvial incision, including the potential role of paraglacial sediment.

  3. An episode of rapid bedrock channel incision during the last glacial cycle, measured with 10Be

    USGS Publications Warehouse

    Reusser, L.; Bierman, P.; Pavich, M.; Larsen, J.; Finkel, R.

    2006-01-01

    We use 10Be to infer when, how fast, and why the Susquehanna River incised through bedrock along the U.S. Atlantic seaboard, one of the world's most prominent and ancient passive margins. Although the rate at which large rivers incise rock is a fundamental control on the development of landscapes, relatively few studies have directly measured how quickly such incision occurs either in tectonically active environments or along passive margins. Exposure ages of fluvially carve d, bedrock strath terraces, preserved along the lower Susquehanna River, demonstrate that even along a passive margin, large rivers are capable of incising through rock for short periods of time at rates approaching those recorded in tectonically active regions, such as the Himalayas. Over eighty samples, collected along and between three prominent levels of strath terraces within Holtwood Gorge, indicate that the Susquehanna River incised more than 10 meters into the Appalachian Piedmont during the last glacial cycle. Beginning ???36 ka, incision rates increased dramatically, and remained elevated until ???14 ka. The northern half of the Susquehanna basin was glaciated during the late Wisconsinan; however, similar rates and timing of incision occurred in the unglaciated Potomac River basin immediately to the south. The concurrence of incision periods on both rivers suggests that glaciation and associated meltwater were not the primary drivers of incision. Instead, it appears that changing climatic conditions during the late Pleistocene promoted an increase in the frequency and magnitude of flood events capable of exceeding thresholds for rock detachment and bedrock erosion, thus enabling a short-lived episode of rapid incision into rock. Although this study has constraine d the timing and rate of bedrock incision along the largest river draining the Atlantic passive margin, the dates alone cannot explain fully why, or by what processes, this incision occurred. However, cosmogenic dating offers

  4. Safety of cesarean delivery through placental incision in patients with anterior placenta previa

    PubMed Central

    Hong, Deok-Ho; Kim, Eugene; Kyeong, Kyu-Sang; Hong, Seung Hwa

    2016-01-01

    Objective To demonstrate the safety of fetal delivery through placental incision in a placenta previa pregnancy. Methods We examined the medical records of 80 women with singleton pregnancy diagnosed with placenta previa who underwent cesarean section between May 2010 and May 2015 at the Department of Obstetrics and Gynecology, Chungbuk National University Hospital. Among the women with placenta previa, those who did not have the placenta in the uterine incision site gave birth via conventional uterine incision, while those with anterior placenta previa or had placenta attached to the uterine incision site gave birth via uterine incision plus placental incision. We compared the postoperative hemoglobin level and duration of hospital stay for the mother and newborn of the two groups. Results There was no difference between the placental incision group and non-incision group in terms of preoperative and postoperative hemoglobin change, the amount of blood transfusions required by the mother, newborns with 1-min or 5-min Apgar scores below 7 points or showing signs of acidosis on umbilical cord blood gas analysis result of pH below 7.20. Moreover, neonatal hemoglobin levels did not differ between the two groups. Conclusion Fetal delivery through placental incision during cesarean section for placenta previa pregnancy does not negatively influence the prognosis of the mother or the newborn, and therefore, is considered a safe surgical technique. PMID:27004200

  5. In vivo and in vitro analysis of topographic changes secondary to DSAEK venting incisions

    PubMed Central

    Moshirfar, Majid; Lependu, Monette T; Church, Dane; Neuffer, Marcus C

    2011-01-01

    Introduction Descemet’s stripping automated endothelial keratoplasty (DSAEK) venting incisions may induce irregular corneal astigmatism. The study examines in vivo and in vitro astigmatic effects of venting incisions. Patients and methods In vivo analysis examined eleven eyes of eleven patients who had received DSAEK with venting incisions. A chart review of the eleven eyes including assessment of pre and postoperative refraction and topography was performed. In vitro analysis examined three cadaver eyes which received topographic imaging followed by venting incisions at 4 mm, 6 mm, and 7 mm optical zones. Topographic imaging was then performed again after the incisions. Results Postoperative topographies of eleven eyes demonstrated localized flattening at incision sites and cloverleaf pattern astigmatism. There was a significant difference in corneal irregularity measurement (P = 0.03), but no significant difference in shape factor or change of topographic cylinder. The cloverleaf pattern was found in cadaver eyes with incisions placed at 4 mm and 6 mm optical zones but not at the 7 mm zone. Conclusion DSAEK venting incisions can cause irregular corneal astigmatism that may affect visual outcomes. The authors recommend placement of venting incisions near the 7 mm optical zone. PMID:21966185

  6. In vivo and in vitro analysis of topographic changes secondary to DSAEK venting incisions.

    PubMed

    Moshirfar, Majid; Lependu, Monette T; Church, Dane; Neuffer, Marcus C

    2011-01-01

    Descemet's stripping automated endothelial keratoplasty (DSAEK) venting incisions may induce irregular corneal astigmatism. The study examines in vivo and in vitro astigmatic effects of venting incisions. In vivo analysis examined eleven eyes of eleven patients who had received DSAEK with venting incisions. A chart review of the eleven eyes including assessment of pre and postoperative refraction and topography was performed. In vitro analysis examined three cadaver eyes which received topographic imaging followed by venting incisions at 4 mm, 6 mm, and 7 mm optical zones. Topographic imaging was then performed again after the incisions. Postoperative topographies of eleven eyes demonstrated localized flattening at incision sites and cloverleaf pattern astigmatism. There was a significant difference in corneal irregularity measurement (P = 0.03), but no significant difference in shape factor or change of topographic cylinder. The cloverleaf pattern was found in cadaver eyes with incisions placed at 4 mm and 6 mm optical zones but not at the 7 mm zone. DSAEK venting incisions can cause irregular corneal astigmatism that may affect visual outcomes. The authors recommend placement of venting incisions near the 7 mm optical zone.

  7. Safety of cesarean delivery through placental incision in patients with anterior placenta previa.

    PubMed

    Hong, Deok-Ho; Kim, Eugene; Kyeong, Kyu-Sang; Hong, Seung Hwa; Jeong, Eun-Hwan

    2016-03-01

    To demonstrate the safety of fetal delivery through placental incision in a placenta previa pregnancy. We examined the medical records of 80 women with singleton pregnancy diagnosed with placenta previa who underwent cesarean section between May 2010 and May 2015 at the Department of Obstetrics and Gynecology, Chungbuk National University Hospital. Among the women with placenta previa, those who did not have the placenta in the uterine incision site gave birth via conventional uterine incision, while those with anterior placenta previa or had placenta attached to the uterine incision site gave birth via uterine incision plus placental incision. We compared the postoperative hemoglobin level and duration of hospital stay for the mother and newborn of the two groups. There was no difference between the placental incision group and non-incision group in terms of preoperative and postoperative hemoglobin change, the amount of blood transfusions required by the mother, newborns with 1-min or 5-min Apgar scores below 7 points or showing signs of acidosis on umbilical cord blood gas analysis result of pH below 7.20. Moreover, neonatal hemoglobin levels did not differ between the two groups. Fetal delivery through placental incision during cesarean section for placenta previa pregnancy does not negatively influence the prognosis of the mother or the newborn, and therefore, is considered a safe surgical technique.

  8. Incidence of lower eyelid complications after a transconjunctival approach: influence of repeated incisions.

    PubMed

    Yamashita, Masanobu; Kishibe, Miyuki; Shimada, Kenichi

    2014-07-01

    Although many authors have described advantages of the transconjunctival approach, few reports describe risks of postoperative lower eyelid complications with repeated incisions. The objective of this study was to investigate whether the incidence of postoperative lower eyelid complication using the transconjunctival approach was different, depending on the time of incision. Patients who underwent orbital bony surgery at the Kanazawa Medical University Hospital between 1996 and 2012 were reviewed. Patients were divided into a group that underwent single transconjunctival incision and a group that underwent repeated incisions. Intraoperative and postoperative complications, including eyelid ectropion, entropion, and scleral show, were compared between the groups. A total of 154 transconjunctival incisions were made in 145 patients (mean age, 35.6 y; 99 men and 46 women), who were observed for a mean of 14 months (range, 6-97 mo). Two patients had eyelid lacerations with inferior lacrimal canaliculus injuries. Lower eyelid malposition requiring operative correction occurred in 3 of the 140 patients in group A (2.1%) and in 3 of the 14 patients in group B (21.4%) (P = 0.01). The total postoperative complication rate in patients with a single incision was 5.0% (n = 7), and that for repeated incisions (2-5 times) was 35.7% (n = 5) (P = 0.001). The total complication rate of transconjunctival incision was slightly high. Although repeated incision cases were significantly more frequent, the eyelid could be corrected without visible scarring although eyelid complications occurred.

  9. First Report: Linear Incision for Placement of a Magnetically Coupled Bone-Anchored Hearing Implant.

    PubMed

    Barry, Jonnae Y; Reghunathan, Saranya; Jacob, Abraham

    2017-02-01

    Discuss use of a linear incision for placement of a magnetically coupled bone anchored hearing implant. Case series. Two patients underwent placement of magnetically coupled bone-anchored hearing implants (BAHI) through linear incisions. The first, a 40-year-old female with congenital single-sided deafness, previously had successful implantation of a percutaneous bone anchored hearing implant through a linear incision; unfortunately, she developed pain and intermittent drainage at her abutment site with time, resulting in a request for removal of her device. As an alternative to complete removal, we offered to replace the percutaneous implant with a magnetically coupled BAHI, employing the same linear incision previously. The second patient, a 53-year-old obese female with limited neck mobility and mixed hearing loss, underwent primary placement of a magnetically coupled BAHI through a linear incision. Limitations in neck mobility and patient body habitus precluded use of a traditional C-shaped incision. Both patients underwent surgery successfully, healed without incident, had their devices activated 6 weeks after their procedures, and are able to wear their implants more than 8 hours per day without discomfort. Surgical techniques for bone-anchored implants continue to evolve. Though manufacturers of magnetically coupled devices recommend using C-shaped incisions with large skin flaps, our first reported cases suggest that a small linear incision immediately overlying the implant magnet may be an acceptable alternative. Potential benefits include a smaller incision, less hair removal, smaller flap, decreased surgical time, and less postoperative pain.

  10. Comparison of fibrin glue and suture in the healing of teat incisions in lactating goats.

    PubMed

    Alan, M; Yener, Z; Tasal, I; Bakir, B

    2008-05-01

    The aims of this study were to investigate whether fibrin glue can be used to close experimentally induced incisions of the teat (mammary papillae) in lactating goats and to compare the healing of the glued with the sutured incisions. Four clinically healthy lactating dairy goats, namely 8 mammary papillae were used. After surgical preparation of the papillae, a 3.5 cm long incision of each papilla was made through skin, muscular layer and mucosa into the papillary sinus. The wounds in the right papillae in all goats were closed with U-shaped uninterrupted 00 chromic catgut sutures. The wounds in the left papillae in all goats were closed, using fibrin glue. One incision was seen to be dehisced and fistulous one day after in fibrin glued teats. The animals were slaughtered 8 days after surgical manipulation. The mammary papillae were removed and examined in the viewpoint on gross and microscopic findings. The healing of wounds was slower and feeble in glued mammary papillary incisions, however faster and stronger in sutured incisions on day 8 after operations. But, available outcomes like less tissue thickness and positive cosmetic results could be obtained byfibrin glue used on mammary papillary incisions, which are very important for teats to be milked by hand and milking machine. Results suggest that it is advisable to use only one or two simple interrupted sutures in teat incisions glued with fibrin to prevent the dehiscence but with a more reliable healing than the sutured incisions.

  11. Differential diagnosis and management of giant fibroadenoma: comparing excision with reduction mammoplasty incision and excision with inframammary incision.

    PubMed

    Ugburo, Andrew O; Olajide, Thomas O; Fadeyibi, Idowu O; Mofikoya, Bolaji O; Lawal, Abdulrazzaq O; Osinowo, Adedapo O

    2012-10-01

    Giant fibroadenoma (GFA) may present with breast asymmetry and can be excised with an inframammary incision (IFI) or reduction mammoplasty incision (RMI). This study investigated the clinical presentation and compared excision with the IFI and RMI. All patients with benign breast tumours greater than 5 cm underwent core needle biopsy and a histopathological diagnosis. All confirmed GFA had their clinical details documented and randomised into two groups for excision with an IFI or RMI. Twenty-two patients were studied. The age range was 12-46 years, mean 21.18 ± 2.22 years. The patients were divided into two groups: a juvenile group (n = 16) (73%) aged 12-18 years, mean age 14.06 ± 0.42 years, and a perimenopausal group (n = 5) aged 28-46 years. The juvenile group showed cyclic increases in breast size monthly with menstruation while the perimenopausal showed an initial slow growth of 6-24 months followed by a rapid growth. Fifteen patients (68%) had excision biopsy with IMI and seven patients with RMI. Seven of the patients treated with IFI had minimal preoperative asymmetry and satisfactory aesthetic outcome. Among the patients with severe preoperative asymmetry treated with IFI (n = 8) and RMI (n = 7), those treated with IFI had persistent postoperative skin redundancy and asymmetry, which was not found in those treated with RMI. In conclusion, for patients with significant asymmetry, excision with the IFI was associated with persistent asymmetry while excision with RMI was associated with restoration of symmetry.

  12. Comparison of single incision and multi incision diagnostic laparoscopy on evaluation of diaphragmatic status after left thoracoabdominal penetrating stab wounds

    PubMed Central

    İlhan, Mehmet; Gök, Ali Fuat Kaan; Bademler, Süleyman; Cücük, Ömer Cenk; Soytaş, Yiğit; Yanar, Hakan Teoman

    2017-01-01

    AIM: Single incision diagnostic laparoscopy (SIDL) may be an alternative procedure to multi-incision diagnostic laparoscopy (MDL) for penetrating thoracoabdominal stab wounds. The purpose of this study is sharing our experience and comparing two techniques for diaphragmatic status. MATERIALS AND METHODS: Medical records of 102 patients with left thoracoabdominal penetrating stab injuries who admitted to Istanbul School of Medicine, Trauma and Emergency Surgery Clinic between February 2012 and April 2016 were examined. The patients were grouped according to operation technique. Patient records were retrospectively reviewed for data including, age, sex, length of hospital stay, diaphragm injury rate, surgical procedure, operation time and operation time with wound repair, post-operative complications and accompanying injuries. RESULTS: The most common injury location was the left anterior thoracoabdomen. SIDL was performed on 26 patients. Nine (34.6%) of the 26 patients had a diaphragm injury. Seventy-six patients underwent MDL. Diaphragmatic injury was detected in 20 (26.3%) of 76 patients. The average operation time and post-operative complications were similar; there was no statistically significant difference between MDL and SIDL groups. CONCLUSION: SIDL can be used as a safe and feasible procedure in the repair of a diaphragm wounds. SIDL may be an alternative method in the diagnosis and treatment of these patients. PMID:27934791

  13. Relaxation schemes for Chebyshev spectral multigrid methods

    NASA Technical Reports Server (NTRS)

    Kang, Yimin; Fulton, Scott R.

    1993-01-01

    Two relaxation schemes for Chebyshev spectral multigrid methods are presented for elliptic equations with Dirichlet boundary conditions. The first scheme is a pointwise-preconditioned Richardson relaxation scheme and the second is a line relaxation scheme. The line relaxation scheme provides an efficient and relatively simple approach for solving two-dimensional spectral equations. Numerical examples and comparisons with other methods are given.

  14. Two-year experience with the commercial Gamma Knife Check software.

    PubMed

    Xu, Andy Yuanguang; Bhatnagar, Jagdish; Bednarz, Greg; Novotny, Josef; Flickinger, John; Lunsford, L Dade; Huq, M Saiful

    2016-07-08

    The Gamma Knife Check software is an FDA approved second check system for dose calculations in Gamma Knife radiosurgery. The purpose of this study was to evaluate the accuracy and the stability of the commercial software package as a tool for independent dose verification. The Gamma Knife Check software version 8.4 was commissioned for a Leksell Gamma Knife Perfexion and a 4C unit at the University of Pittsburgh Medical Center in May 2012. Independent dose verifications were performed using this software for 319 radiosurgery cases on the Perfexion and 283 radiosurgery cases on the 4C units. The cases on each machine were divided into groups according to their diagnoses, and an averaged absolute percent dose difference for each group was calculated. The percentage dose difference for each treatment target was obtained as the relative difference between the Gamma Knife Check dose and the dose from the tissue maximum ratio algorithm (TMR 10) from the GammaPlan software version 10 at the reference point. For treatment plans with imaging skull definition, results obtained from the Gamma Knife Check software using the measurement-based skull definition method are used for comparison. The collected dose difference data were also analyzed in terms of the distance from the treatment target to the skull, the number of treatment shots used for the target, and the gamma angles of the treatment shots. The averaged percent dose differences between the Gamma Knife Check software and the GammaPlan treatment planning system are 0.3%, 0.89%, 1.24%, 1.09%, 0.83%, 0.55%, 0.33%, and 1.49% for the trigeminal neuralgia, acoustic neuroma, arteriovenous malformation (AVM), meningioma, pituitary adenoma, glioma, functional disorders, and metastasis cases on the Perfexion unit. The corresponding averaged percent dose differences for the 4C unit are 0.33%, 1.2%, 2.78% 1.99%, 1.4%, 1.92%, 0.62%, and 1.51%, respectively. The dose difference is, in general, larger for treatment targets in the

  15. Two-year experience with the commercial Gamma Knife Check software.

    PubMed

    Xu, Andy Yuanguang; Bhatnagar, Jagdish; Bednarz, Greg; Novotny, Josef; Flickinger, John; Lunsford, L Dade; Huq, M Saiful

    2016-07-01

    The Gamma Knife Check software is an FDA approved second check system for dose calculations in Gamma Knife radiosurgery. The purpose of this study was to evaluate the accuracy and the stability of the commercial software package as a tool for independent dose verification. The Gamma Knife Check software version 8.4 was commissioned for a Leksell Gamma Knife Perfexion and a 4C unit at the University of Pittsburgh Medical Center in May 2012. Independent dose verifications were performed using this software for 319 radiosurgery cases on the Perfexion and 283 radiosurgery cases on the 4C units. The cases on each machine were divided into groups according to their diagnoses, and an averaged absolute percent dose difference for each group was calculated. The percentage dose difference for each treatment target was obtained as the relative difference between the Gamma Knife Check dose and the dose from the tissue maximum ratio algorithm (TMR 10) from the GammaPlan software version 10 at the reference point. For treatment plans with imaging skull definition, results obtained from the Gamma Knife Check software using the measurement-based skull definition method are used for comparison. The collected dose difference data were also analyzed in terms of the distance from the treatment target to the skull, the number of treatment shots used for the target, and the gamma angles of the treatment shots. The averaged percent dose differences between the Gamma Knife Check software and the GammaPlan treatment planning system are 0.3%, 0.89%, 1.24%, 1.09%, 0.83%, 0.55%, 0.33%, and 1.49% for the trigeminal neuralgia, acoustic neuroma, arteriovenous malformation (AVM), meningioma, pituitary adenoma, glioma, functional disorders, and metastasis cases on the Perfexion unit. The corresponding averaged percent dose differences for the 4C unit are 0.33%, 1.2%, 2.78% 1.99%, 1.4%, 1.92%, 0.62%, and 1.51%, respectively. The dose difference is, in general, larger for treatment targets in the

  16. Gamma Knife radiosurgery of large skull base meningiomas.

    PubMed

    Starke, Robert M; Przybylowski, Colin J; Sugoto, Mukherjee; Fezeu, Francis; Awad, Ahmed J; Ding, Dale; Nguyen, James H; Sheehan, Jason P

    2015-02-01

    Stereotactic radiosurgery (SRS) has become a common treatment modality for intracranial meningiomas. Skull base meningiomas greater than 8 cm3 in volume have been found to have worse outcomes following SRS. When symptomatic, patients with these tumors are often initially treated with resection. For tumors located in close proximity to eloquent structures or in patients unwilling or unable to undergo a resection, SRS may be an acceptable therapeutic approach. In this study, the authors review the SRS outcomes of skull base meningiomas greater than 8 cm3 in volume, which corresponds to a lesion with an approximate diameter of 2.5 cm. The authors reviewed the data in a prospectively compiled database documenting the outcomes of 469 patients with skull base meningiomas treated with single-session Gamma Knife radiosurgery (GKRS). Seventy-five patients had tumors greater than 8 cm3 in volume, which was defined as a large tumor. All patients had a minimum follow-up of 6 months, but patients were included if they had a complication at any time point. Thirty patients were treated with upfront GKRS, and 45 were treated following microsurgery. Patient and tumor characteristics were assessed to determine predictors of new or worsening neurological function and tumor progression following GKRS. After a mean follow-up of 6.5 years (range 0.5-21 years), the tumor volume was unchanged in 37 patients (49%), decreased in 26 patients (35%), and increased in 12 patients (16%). Actuarial rat