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Mechanical Valve (mechanical + valve)
Selected AbstractsFive-Year Follow-Up of Valve Replacement with the Jyros Bileaflet Mechanical ValveARTIFICIAL ORGANS, Issue 1 2000Koji Onoda Abstract: Jyros bileaflet rotating valves were implanted as a clinical trial conducted in Japan, and the 5-year results were assessed. Nineteen patients underwent implantation of the valves: 14 in the mitral and 5 in the aortic position. The mean follow-up period was 65.4 ± 15.7 months. There was 1 case of late death due to fatal arrhythmia and another case of cerebral thromboembolism (1.0% per patient year). All survivors were in New York Heart Association class I. On the early postoperative cinefluorography, 8 valves (42.1%) showed rotation of the leaflets. However, in the latest assessment 6 valves (33.3%) showed rotation, some valves had stopped rotation, and others had started to rotate during the follow-up period. The Jyros valve functions effectively, similar to other bileaflet valves. However, because the correlation between thromboembolism and the rotation mechanism is not clear, further follow-up of our patients and more implant studies are necessary to elucidate this issue. [source] Prosthetic Valve Thrombosis Presenting as an Acute Embolic Myocardial Infarction in a Pregnant Patient: Issues on Anticoagulation Regimens and Thrombolytic TherapyECHOCARDIOGRAPHY, Issue 9 2006Padmini Varadarajan M.D. Mechanical valves are inherently thrombogenic and require meticulous anticoagulation. Pregnancy produces a hypercoagulable state and achieving adequate anticoagulation is difficult. We present a pregnant patient who had a nonobstructive thrombus of mechanical mitral valve causing embolic acute myocardial infarction. Issues surrounding management of anticoagulation and use of thrombolytic therapy during pregnancy are discussed. Education regarding the critical nature of adequate anticoagulation in these patients is important. [source] Temperature responsive pore-filled membranes based on a BSA/poly(N -isopropylacrylamide) hydrogelADVANCES IN POLYMER TECHNOLOGY, Issue 1 2008R. Zhang Abstract A temperature-sensitive hydrogel based on a copolymer of BSA and poly(N -isopropylacrylamide) (PNIPAAm) has been synthesized using carbodiimide chemistry. Fourier transform infrared spectroscopy confirmed primary complex formation between carbodiimide-activated carboxylic acids on the protein with protein amino groups. As a result of temperature-induced conformational changes in PNIPAAm grafted onto the protein backbone, these protein hydrogels show significant morphological changes in response to temperature. The structural changes of the gels in response to temperature were assessed using scanning electron microscopy, and the effect of temperature on their balance of hydrophobicity was found using turbidity measurements. Composite pore-filled membranes formed by impregnating glass fiber filters with the polymer mixture prior to gelation were used to determine permeability changes in response to temperature using both low (riboflavin) and intermediate (lysozyme) molecular weight diffusates. Clear correlation was found between changes in morphology, turbidity, and gel permeability as the gel temperature was increased from 24,37°C. In the case of permeability studies, significant transport of lysozyme only occurred at temperatures above the lower transition temperature of the hydrogel, suggesting the gel was acting as a mechanical "valve" to control flux. © 2008 Wiley Periodicals, Inc. Adv Polym Techn 27:27,34, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/adv.20113 [source] Delayed Presentation of Injury to the Sinus of Valsalva with Aortic Regurgitation Resulting from Penetrating Cardiac WoundsJOURNAL OF CARDIAC SURGERY, Issue 3 2003Narutoshi Hibino M.D. An emergency operation was performed successfully to repair the penetrating cardiac injury of the right ventricular outflow tract without using cardiopulmonary bypass. Two years after the operation, he was complained of dyspnea and a continuous murmur was detected. Echocardiography and cardiac catheterization revealed aorto-right ventricular fistula in the sinus of valsalva with aortic regurgitation. In operation, the healed laceration of the right coronary cusp and the fistula between aorta and right ventricle were identified. The fistula was closed using a Dacron patch and the aortic valve was replaced with a mechanical valve. Long-term follow-up of penetrating thoracic injuries is important for detecting underlying intracardiac lesions. (J Card Surg 2003;18:236-239) [source] Treatment for Mechanical Valve Thrombosis in the Right Heart: Combined Pharmacological and Mechanical ThrombolysisARTIFICIAL ORGANS, Issue 8 2010Shigeaki Aoyagi Abstract We report clinical results of combined pharmacological and mechanical thrombolysis for mechanical prosthetic valve thrombosis (PVT) in the right heart. Between January 1992 and December 2008, combined thrombolysis, which consisted of an intravenous infusion of urokinase together with mechanical disruption of thrombus in a prosthetic valve by temporarily increasing the cardiac pacing rate, was performed in three patients with four cases of mechanical PVT in the right heart. The prosthetic valve in all three patients was a bileaflet mechanical valve, and was located in the tricuspid position in two patients and in the pulmonary position in the remaining patient. PVT was diagnosed by echocardiography and cineradiography. Thrombolysis was successful in all four cases in the three patients, and no hemorrhagic complications or clinically symptomatic pulmonary embolisms were observed. Mechanical disruption of thrombus using a pacemaker appears to be an effective adjunctive modality to thrombolysis with fibrinolytic agents for PVT in the right heart. Combined pharmacological and mechanical thrombolysis may improve success rates and reduce the time required for thrombolysis of PVT. [source] Transvenous Cardioverter-Defibrillator Implantation in a Patient with Tricuspid Mechanical ProsthesisJOURNAL OF CARDIOVASCULAR ELECTROPHYSIOLOGY, Issue 3 2007MAURO BIFFI M.D. Background. A 64-year-old woman was referred to our center because of poorly tolerated ventricular tachycardia (VT) at 210 bpm due to an old myocardial infarction. The patient had been operated on at age of 20 for mitral valve commissurolysis, at age of 49 for ductal carcinoma, at age of 56 for mitral valve replacement, and at age of 61 for tricuspid valve replacement. Left ventricular EF was 31%. The patient was in permanent atrial fibrillation (AF) since the age of 53. She had undergone three cardiac surgery procedures, ending with two prosthetic mechanical valves. The cardiac surgery team advised against an epicardial ICD implantation. Results. We achieved a fully transvenous implant, with a screw-in defibrillation coil in the low right atrium and a bipolar pacing/sensing lead in a posterolateral branch of the coronary sinus. Pacing/sensing parameters were reliable, and effective defibrillation occurred at 20 J by a stepdown protocol. During 16-month follow-up, three VT episodes at 210 bpm were terminated by antitachycardia pacing (ATP) therapy. Left ventricular pacing/sensing was stable at long term. Conclusion. Thanks to technologic improvements, transvenous ICD implantation is feasible and safe in patients with a tricuspid mechanical prosthesis. [source] Treatment of mechanical valve thrombosis during pregnancyCLINICAL CARDIOLOGY, Issue 6 2007Calvin Choi M.D. Abstract Pregnant patients with mechanical valves require anticoagulation. The risk of bleeding and embryopathy associated with oral anticoagulation must be weighed against the risk of valve thrombosis. In the presence of a mechanical valve thrombosis, an appropriate treatment modality must be selected, as it is critical for the health of mother and fetus. In this review, we present a pregnant patient with mechanical valve thrombosis (MVT) who underwent thrombolytic therapy, subsequent anticoagulation according to available guidelines, and delivered a healthy baby at full term. Copyright © 2007 Wiley Periodicals, Inc. [source] | ||||||||||