The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Hideaki Kado - One of the best experts on this subject based on the ideXlab platform.
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modification of expanded Polytetrafluoroethylene valved conduit using the thin type leaflets
The Journal of Thoracic and Cardiovascular Surgery, 2018Co-Authors: Yusuke Yamamoto, Takako Miyazaki, Masaaki Yamagishi, Hitoshi Yaku, Satoshi Asada, Yoshinobu Maeda, Hideaki KadoAbstract:Abstract Objectives The expanded Polytetrafluoroethylene conduit with fan-shaped leaflets and bulging sinuses for right ventricular outflow tract reconstruction was modified with a newly developed thin-type expanded Polytetrafluoroethylene leaflet. The purpose of this study was to evaluate the clinical outcomes and hemodynamic performance of the modified conduit. Methods From January 2010 to December 2013, 149 patients underwent definitive right ventricular outflow tract reconstruction using the expanded Polytetrafluoroethylene conduit; the 55 patients receiving a conventional conduit (group N) were compared with the 94 patients receiving a modified conduit (group T). Results There were no conduit-related deaths, operative deaths, or reimplantations for conduit failure. The overall survival and freedom from reintervention for conduit-related reasons at 3 years were 98.2% versus 95.6% ( P = .438) and 94.7% versus 97.9% ( P = .954) for groups N and T, respectively. The mean peak pressure gradients were 22.6 ± 15.6 mm Hg versus 18.2 ± 11.5 mm Hg ( P = .161), and in the subanalysis within small-sized conduits, they were 30.2 ± 16.5 mm Hg versus 20.4 ± 10.7 mm Hg ( P = .034). Regarding conduit insufficiency, the modified conduit showed a significantly worse grade of insufficiency ( P = .014) only in the subanalysis within large-sized conduits. Conclusions Although the clinical outcomes did not differ within midterm observation, the thin-type expanded Polytetrafluoroethylene leaflet was considered to be suitable for the small-sized conduits, but not for large-sized conduits, based on the comparison of the hemodynamic performance. Long-term follow-up is necessary to address the appropriate sheet type for middle-sized conduits and to estimate the durability of the thin-type leaflet.
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expanded Polytetrafluoroethylene valved conduit and patch with bulging sinuses in right ventricular outflow tract reconstruction
The Journal of Thoracic and Cardiovascular Surgery, 2007Co-Authors: Takako Miyazaki, Masaaki Yamagishi, Toshihide Nakano, Atsuhiro Nakashima, Kouji Fukae, Hitoshi Yaku, Hideaki KadoAbstract:Objectives No specific prosthetic material is currently recognized as being the most suitable for right ventricular outflow tract reconstruction for congenital heart defects. Prosthetic valves are subject to wear and stress because they do not create vortex flow, which helps natural valves to close. We designed a fan-shaped expanded Polytetrafluoroethylene valved conduit and patch with bulging sinuses that create vortex flow, making them more reliable over the long term. Methods Bulging sinuses were formed on a sheet of expanded Polytetrafluoroethylene using a specially designed mold. Fan-shaped expanded Polytetrafluoroethylene sheets (0.1 mm thick) were anastomosed to the edge of the bulging sinuses as valve leaflets, creating monocuspid, bicuspid, or tricuspid valves. These valves were implanted in 157 patients undergoing right ventricular outflow tract reconstruction (age 16 days to 45.4 years, median 2.0 years), in 48 patients as a conduit, and in 109 patients as a patch. Valve function was followed up by echocardiography for 5.6 to 63.7 months (mean 20.8 months). Results There was no mortality or morbidity, and no patients required reoperation during follow-up. No patients had stenosis, and regurgitation was less than mild in all patients with conduits and moderate in 15 patients (13.8%) with patches, but moderate regurgitation did not further develop during follow-up. Valve motion was fully maintained in all patients. Conclusions The expanded Polytetrafluoroethylene valved conduits and patches with bulging sinuses showed excellent early-to-midterm results. The valved conduits and patches seem to be promising alternatives to homografts in right ventricular outflow tract reconstruction. Their function will be followed up further.
Tirone E David - One of the best experts on this subject based on the ideXlab platform.
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chordal replacement with Polytetrafluoroethylene sutures for mitral valve repair a 25 year experience
The Journal of Thoracic and Cardiovascular Surgery, 2013Co-Authors: Tirone E David, Susan Armstrong, Joan IvanovAbstract:Objective The study objective was to examine the late results of mitral valve repair with chordal replacement with Polytetrafluoroethylene sutures. Methods From 1986 to 2004, 606 consecutive patients with degenerative mitral regurgitation had mitral valve repair with chordal replacement with Polytetrafluoroethylene sutures. Patients' mean age was 57 years, and 73.6% were men. Isolated prolapse of the anterior leaflet was present in 17.6% of patients, isolated posterior leaflet prolapse was present in 29.5% of patients, and bileaflet prolapse was present in 52.9% of patients. Prolapse was corrected by creating 2 to 38 neochords of Polytetrafluoroethylene sutures (mean, 13 ± 9 per patient). The mean follow-up was 10.1 years, and 96% of the patients had multiple echocardiographic studies over the years. Results There were 5 early and 106 late deaths. Age, diabetes, hypertension, chronic obstructive lung disease, New York Heart Association functional classes III and IV, and ejection fraction less than 40% were independent predictors of mortality. At 18 years, freedom from reoperation on the mitral valve was 90.2% ± 2.4%, freedom from recurrent severe mitral regurgitation was 91.0% ± 2.7%, and freedom from moderate or severe mitral regurgitation was 67.5% ± 4.2%. Cox regression analysis revealed that isolated prolapse of the anterior leaflet was predictive of reoperation, and that older age, hypertension, and left ventricular ejection fraction less than 40% were predictive of recurrent moderate or severe mitral regurgitation. Conclusions Chordal replacement with Polytetrafluoroethylene sutures expands the indication of repair to patients with prolapse of multiple segments. Valve function remains stable in most patients during the first 2 decades of follow-up.
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ruptured synthetic expanded Polytetrafluoroethylene chordae tendinae
Cardiovascular Pathology, 2004Co-Authors: Tirone E David, Jagdish Butany, Michael J CollinsAbstract:Synthetic sutures are used for mitral valve repair and as synthetic chordae tendinae to resuspend the mitral valve. The sutures soon get covered with connective tissue and work well for long periods. We report the first instance (in the literature) of rupture of a synthetic (PTFE) chordae tendinae. The synthetic suture (PTFE) was associated with calcification.
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long term results of mitral valve repair for myxomatous disease with and without chordal replacement with expanded Polytetrafluoroethylene sutures
The Journal of Thoracic and Cardiovascular Surgery, 1998Co-Authors: Tirone E David, Ahmad S Omran, Susan Armstrong, Joan IvanovAbstract:Abstract Objective: This study was carried out to evaluate the long-term results of mitral valve repair for mitral regurgitation caused by myxomatous disease of the mitral valve and the late effects of chordal replacement with expanded Polytetrafluoroethylene sutures in this operation. Methods: A total of 324 patients with mitral regurgitation caused by myxomatous disease underwent mitral valve repair from 1981 to 1995; the group comprised 241 men and 83 women whose mean age was 58 ± 14 years. Chordal replacement with expanded Polytetrafluoroethylene sutures has been performed in 165 patients since 1985. Most of the patients who had chordal replacement with expanded Polytetrafluoroethylene sutures had prolapse of the anterior leaflet or prolapse of both leaflets, whereas most patients who had mitral valve repair without chordal replacement had prolapse of the posterior leaflet. Patients were followed up at annual intervals and had a Doppler echocardiographic study. The follow-up was complete and extended from 6 to 156 months (mean 36 ± 30 months). Results: Two operative and 21 late deaths occurred (14 cardiac and 7 noncardiac). At 10 years the actuarial survival was 75% ± 5%, the freedom from stroke was 94% ± 2%, the freedom from transient ischemic attacks was 92% ± 4%, the freedom from endocarditis was 99% ± 1%, the freedom from mitral valve reoperation was 96% ± 1%, and the freedom from severe mitral regurgitation was 93% ± 3%. Chordal replacement with expanded Polytetrafluoroethylene sutures had no effect on any of these end points. Conclusions: Mitral valve repair was feasible in most patients with mitral regurgitation caused by myxomatous disease and it was associated with low rates of valve-related complications. Chordal replacement with expanded Polytetrafluoroethylene had no adverse effect on the late outcome and was believed to have increased the probability of mitral valve repair. (J Thorac Cardiovasc Surg 1998;115:1279-86)
Takako Miyazaki - One of the best experts on this subject based on the ideXlab platform.
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modification of expanded Polytetrafluoroethylene valved conduit using the thin type leaflets
The Journal of Thoracic and Cardiovascular Surgery, 2018Co-Authors: Yusuke Yamamoto, Takako Miyazaki, Masaaki Yamagishi, Hitoshi Yaku, Satoshi Asada, Yoshinobu Maeda, Hideaki KadoAbstract:Abstract Objectives The expanded Polytetrafluoroethylene conduit with fan-shaped leaflets and bulging sinuses for right ventricular outflow tract reconstruction was modified with a newly developed thin-type expanded Polytetrafluoroethylene leaflet. The purpose of this study was to evaluate the clinical outcomes and hemodynamic performance of the modified conduit. Methods From January 2010 to December 2013, 149 patients underwent definitive right ventricular outflow tract reconstruction using the expanded Polytetrafluoroethylene conduit; the 55 patients receiving a conventional conduit (group N) were compared with the 94 patients receiving a modified conduit (group T). Results There were no conduit-related deaths, operative deaths, or reimplantations for conduit failure. The overall survival and freedom from reintervention for conduit-related reasons at 3 years were 98.2% versus 95.6% ( P = .438) and 94.7% versus 97.9% ( P = .954) for groups N and T, respectively. The mean peak pressure gradients were 22.6 ± 15.6 mm Hg versus 18.2 ± 11.5 mm Hg ( P = .161), and in the subanalysis within small-sized conduits, they were 30.2 ± 16.5 mm Hg versus 20.4 ± 10.7 mm Hg ( P = .034). Regarding conduit insufficiency, the modified conduit showed a significantly worse grade of insufficiency ( P = .014) only in the subanalysis within large-sized conduits. Conclusions Although the clinical outcomes did not differ within midterm observation, the thin-type expanded Polytetrafluoroethylene leaflet was considered to be suitable for the small-sized conduits, but not for large-sized conduits, based on the comparison of the hemodynamic performance. Long-term follow-up is necessary to address the appropriate sheet type for middle-sized conduits and to estimate the durability of the thin-type leaflet.
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expanded Polytetrafluoroethylene valved conduit and patch with bulging sinuses in right ventricular outflow tract reconstruction
The Journal of Thoracic and Cardiovascular Surgery, 2007Co-Authors: Takako Miyazaki, Masaaki Yamagishi, Toshihide Nakano, Atsuhiro Nakashima, Kouji Fukae, Hitoshi Yaku, Hideaki KadoAbstract:Objectives No specific prosthetic material is currently recognized as being the most suitable for right ventricular outflow tract reconstruction for congenital heart defects. Prosthetic valves are subject to wear and stress because they do not create vortex flow, which helps natural valves to close. We designed a fan-shaped expanded Polytetrafluoroethylene valved conduit and patch with bulging sinuses that create vortex flow, making them more reliable over the long term. Methods Bulging sinuses were formed on a sheet of expanded Polytetrafluoroethylene using a specially designed mold. Fan-shaped expanded Polytetrafluoroethylene sheets (0.1 mm thick) were anastomosed to the edge of the bulging sinuses as valve leaflets, creating monocuspid, bicuspid, or tricuspid valves. These valves were implanted in 157 patients undergoing right ventricular outflow tract reconstruction (age 16 days to 45.4 years, median 2.0 years), in 48 patients as a conduit, and in 109 patients as a patch. Valve function was followed up by echocardiography for 5.6 to 63.7 months (mean 20.8 months). Results There was no mortality or morbidity, and no patients required reoperation during follow-up. No patients had stenosis, and regurgitation was less than mild in all patients with conduits and moderate in 15 patients (13.8%) with patches, but moderate regurgitation did not further develop during follow-up. Valve motion was fully maintained in all patients. Conclusions The expanded Polytetrafluoroethylene valved conduits and patches with bulging sinuses showed excellent early-to-midterm results. The valved conduits and patches seem to be promising alternatives to homografts in right ventricular outflow tract reconstruction. Their function will be followed up further.
Mark W Turrentine - One of the best experts on this subject based on the ideXlab platform.
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right ventricular outflow tract reconstruction with a Polytetrafluoroethylene monocusp valve a twelve year experience
The Journal of Thoracic and Cardiovascular Surgery, 2007Co-Authors: John W Brown, Mark Ruzmetov, Palaniswamy Vijay, Mark D Rodefeld, Mark W TurrentineAbstract:Objective Transannular patching of the right ventricular outflow tract results in pulmonary insufficiency. Biologic monocusp valves prevent early pulmonary insufficiency but usually become nonfunctional in less than 1 year. Polytetrafluoroethylene monocusp leaflets demonstrated favorable characteristics in our animal studies and have been applied to a variety of right ventricular outflow tract reconstructions at our institution. Methods From 1994 through 2006, 192 patients (mean age, 3.3 ± 5.0 years) underwent right ventricular outflow tract reconstruction with a Polytetrafluoroethylene monocusp valve (192 patients; 202 implants). Intraoperative, early postoperative, and late follow-up echocardiographic data (mean interval, 4.9 ± 3.1 years; range, 6 months to 12 years) were retrospectively obtained to compare clinical outcomes among three preoperative diagnostic groups: patients undergoing initial repair of tetralogy of Fallot or pulmonary atresia/ventricular septal defect (group I), patients undergoing redo right ventricular outflow tract procedures (group II), and patients undergoing complex initial repairs (group III). Results There were 4 early and 5 late deaths (9/192; 5%). The difference between the preoperative and postoperative peak right ventricular outflow tract gradients was significant (71.2 vs 23.1; P P = .01) and from group III (90%; P = .02), but there was no difference between groups I and III. Conclusions Use of a Polytetrafluoroethylene monocusp valve prevents early and significantly reduces midterm pulmonary insufficiency. It is relatively inexpensive, easy to construct, and remains free from significant stenosis in the majority of patients. We have not witnessed significant calcification or pulmonary embolization, and the only antithrombic agent used has been low-dose aspirin.
Ji Ae Park - One of the best experts on this subject based on the ideXlab platform.
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a new simplified technique for making tricuspid expanded Polytetrafluoroethylene valved conduit for right ventricular outflow reconstruction
The Annals of Thoracic Surgery, 2013Co-Authors: Si Chan Sung, Yun-hee Chang, Ji Ae ParkAbstract:Several methods of making expanded Polytetrafluoroethylene valved conduit have been reported, but these techniques are complicated and less reproducible. We have developed a new simplified technique for making a tricuspid expanded Polytetrafluoroethylene valved conduit for right ventricular outflow tract reconstruction and have been using this conduit for approximately 3 years with excellent results. Our technique is straightforward and reproducible, and the cusps in the conduit are durable due to the use of a specialized suturing technique.
