Regurgitant Commissure Flow Through a Closed Polymeric Heart Valve

2010 ◽  
Author(s):  
Scott C. Corbett ◽  
Hamid N.-Hashemi ◽  
Ahmet U. Coskun
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Structural Changes ◽  
Patient Survival ◽  
Improve Patient Survival ◽  
Flow Disturbances ◽  
Limited Life ◽  
Flow Through ◽  
Valve Prostheses ◽  
Improve Patient

While heart valve prostheses have been used successfully since 1960, outcomes are far from ideal. The underlying problem with bioprostheses is a limited life from structural changes such as calcification and leaflet wear, leading to valve failure. The underlying problem with mechanical heart valves is the presence of flow disturbances which necessitate anticoagulation. A polyurethane valve has the potential to improve upon the shortcomings of existing valves and ultimately improve patient survival.

Characterization of a Novel Polymeric Trileaflet Heart Valve Prosthesis

2009 ◽  
Author(s):  
Scott C. Corbett ◽  
Neil Verma ◽  
Parnian Boloori Zadeh ◽  
Ahmet U. Coskun ◽  
Hamid N.-Hashemi
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Structural Changes ◽  
Survival Rates ◽  
Valve Prosthesis ◽  
Improve Patient Survival ◽  
Limited Life ◽  
Valve Prostheses ◽  
Improve Patient

While heart valve prostheses have been used successfully since 1960, 10-year survival rates still range from 37–58% [1]. The underlying problem with bioprostheses is a limited life from structural changes such as calcification and leaflet wear, leading to valve failure [2]. Biological tissue fixation and methods used to mount the tissue to a supporting stent can be blamed for this shortcoming. The underlying problem with mechanical heart valves is the presence of a centrally located leaflet, or occluder. It propagates high velocity jets, turbulence and areas of stagnation: the disturbances which necessitate anticoagulation [3]. A polyurethane valve has the potential to improve upon the shortcomings of existing valves and ultimately improve patient survival.

scholarly journals Primary Malignant Melanoma of the Vagina without Metastasis: A Rare Case and Review of Literature

2020 ◽  
Author(s):  
Wilson Bizimana ◽  
Gloria Akimana ◽  
Arthur Semedo Insumbo ◽  
Hounayda Jerguigue ◽  
Rachida Latib ◽  
...  
Keyword(s):  
Malignant Melanoma ◽  
Patient Survival ◽  
Rare Condition ◽  
Primary Malignant Melanoma ◽  
Imaging Features ◽  
Review Of Literature ◽  
Pelvic Magnetic Resonance Imaging ◽  
Improve Patient Survival ◽  
Appropriate Treatment ◽  
Improve Patient

AbstractMalignant melanoma of vagina is a rare condition. Its histogenesis has been debated and the positive diagnosis is based on immunohistochemistry. Pelvic magnetic resonance imaging remains the gold standard for assessing locoregional extension status and post-treatment surveillance of melanoma of vagina. The observation concerned a 53-year-old woman with no specific history who presented a primary malignant melanoma of vagina without secondary locations. To date, the case is the second one reported in the literature. Early diagnosis of the malignant melanoma of vagina may improve patient survival because late diagnoses are punctuated by poor prognosis. We have presented epidemiological with etiopathogenic characteristics and described all imaging features to stage the tumor and to conduct the appropriate treatment.

Large Displacement Flexural Properties of Tissue Engineered Heart Valve Scaffolds

2000 ◽  
Author(s):  
Michael S. Sacks ◽  
Sanjay Kaushal ◽  
John E. Mayer
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Critical Test ◽  
Bioprosthetic Heart Valves ◽  
Property Evaluation ◽  
Fundamental Information ◽  
Tissue Engineered Heart Valve ◽  
Valve Prostheses ◽  
Tissue Engineered Heart Valves

Abstract The need for improved heart valve prostheses is especially critical in pediatric applications, where growth and remodeling are essential. Tissue engineered heart valves (TEHV) have functioned in the pulmonary circulation of growing lambs for up to four months [1], and thus can potentially overcome limitations of current bioprosthetic heart valves. Despite these promising results, significant questions remain. In particular, the role of scaffold mechanical properties in optimal extra-cellular matrix development, as well as TEHV durability, are largely unexplored. We have previously demonstrated flexure testing as a sensitive and critical test for BHV tissue mechanical property evaluation [2]. The following study was conducted to determine the feasibility of using this technique to provide fundamental information required for optimizing TEHV scaffold designs.

Abstract A56: Identification of a micro RNA profile to predict response to therapy and improve patient survival in ovarian cancer

2013 ◽  
Author(s):  
Marina Rigau ◽  
Blanca Majem ◽  
Tatiana Altadill ◽  
Lucia Lanau ◽  
José-Luis Sánchez-Iglesias ◽  
...  
Keyword(s):  
Ovarian Cancer ◽  
Patient Survival ◽  
Response To Therapy ◽  
Micro Rna ◽  
Improve Patient Survival ◽  
Improve Patient

scholarly journals Surgical Resection and Pazopanib Treatment for Recurrent Cardiac Angiosarcoma

2019 ◽  
Vol 12 ◽  
pp. 2632010X1983126
Author(s):  
Yuki Nakamura ◽  
Koichi Toda ◽  
Shigeru Miyagawa ◽  
Yasushi Yoshikawa ◽  
Hiroki Hata ◽  
...  
Keyword(s):  
Surgical Resection ◽  
Poor Prognosis ◽  
Tumor Recurrence ◽  
Kinase Inhibitor ◽  
Patient Survival ◽  
Optimal Management ◽  
Improve Patient Survival ◽  
Cardiac Angiosarcoma ◽  
Sarcoma Treatment ◽  
Improve Patient

Cardiac sarcoma treatment is challenging for surgeons because of frequent tumor recurrence and poor prognosis. In addition, optimal management of recurrences is not well established. The multi-targeted tyrosine kinase inhibitor, pazopanib, was recently approved for soft-tissue sarcoma. Herein, we present a case involving recurrent cardiac angiosarcoma where the patient survived for 2 years with complete remission of disease after repeated surgical resection and treatment with oral pazopanib. Based on our experience, aggressive surgical resection combined with pazopanib may be a valid treatment for recurrent cardiac angiosarcoma to improve patient survival.

Surveillance of hepatocellular carcinoma in patients with hepatitis C virus infection may improve patient survival

2006 ◽  
Vol 26 (5) ◽  
pp. 543-551 ◽  
Author(s):  
Hironori Tanaka ◽  
Kazuhiro Nouso ◽  
Haruhiko Kobashi ◽  
Yoshiyuki Kobayashi ◽  
Shin-ichiro Nakamura ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Virus Infection ◽  
Patient Survival ◽  
Hepatitis C Virus Infection ◽  
Improve Patient Survival ◽  
Improve Patient

Biomechanical Simulations of Bioprosthetic Heart Valve Deformations

2006 ◽  
Author(s):  
Wei Sun ◽  
Hengchu Cao ◽  
Jim Davidson ◽  
Michael Sacks
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Stress Concentrations ◽  
Bioprosthetic Heart Valves ◽  
Structural Fatigue ◽  
Structural Deterioration ◽  
Bending Stresses ◽  
Improved Performance ◽  
Valve Prostheses ◽  
Opening And Closing

Previous research has suggested that the structural deterioration in porcine bioprosthetic heart valves (BHV) may be correlated with the regions of high tensile and bending stresses acting on the leaflets during opening and closing[1, 2]. Stress concentrations within the cusp can either directly accelerate tissue structural fatigue damage, or initiate calcification by causing structural disintegration, enabling multiple pathways of calcification that can lead to valve failure[3,4]. In the case of bovine pericardial heart valve prostheses, structural failure of the leaflets is rare but calcification has been observed. Although details of the process are unclear, it is generally assumed that the design of the pericardial valve, which gives a stress-reduced state of the leaflets, is likely to provide improved performance in long-term applications.

An Initial Parametric Study on Fluid Flow Through Bileaflet Mechanical Heart Valves Using Computational Fluid Dynamics

1994 ◽  
Vol 208 (2) ◽  
pp. 63-72 ◽  
Author(s):  
M J King ◽  
T David ◽  
J Fisher
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Heart Valve ◽  
Heart Valves ◽  
Mechanical Heart Valve ◽  
Volumetric Flow Rate ◽  
Flow Fields ◽  
Opening Angle ◽  
Bileaflet Mechanical Heart Valve ◽  
Flow Through

The effect of leaflet opening angle on flow through a bileaflet mechanical heart valve has been investigated using computational fluid dynamics (CFD). Steady state, laminar flow for a Newtonian fluid at a Reynolds number of 1500 was used in the two-dimensional model of the valve, ventricle, sinus and aorta. This computational model was verified using one-dimensional laser Doppler velocimetry (LDV). Although marked differences in the flow fields and energy dissipation of the jets downstream of the valve were found between the CFD predictions and the three-dimensional experimental model, both methods showed similar trends in the changes of the flow fields as the leaflet opening angle was altered. As the opening angle increased the area of recirculating fluid downstream of the leaflets, the pressure drop across the valve and the volumetric flow rate through the outer orifice decreased. For opening angles greater than 80° the jet through the outer orifice recombined with the central jet downstream of the leaflet; for an opening angle of 78° the jet through the outer orifice impinged on the aortic wall before recombining with the central jet. This study suggests that the opening angle has a marked effect on the flow downstream of the bileaflet mechanical heart valve and that valves with opening angles greater than 80° are preferable.

scholarly journals Lung cancer requires multidisciplinary treatment to improve patient survival: A case report

2017 ◽  
Vol 14 (3) ◽  
pp. 3035-3038 ◽  
Author(s):  
Aldo Pezzuto ◽  
Fabrizio Terzo ◽  
Maria Laura Graziani ◽  
Alberto Ricci ◽  
Pierdonato Bruno ◽  
...  
Keyword(s):  
Lung Cancer ◽  
Case Report ◽  
Patient Survival ◽  
Multidisciplinary Treatment ◽  
Improve Patient Survival ◽  
Improve Patient

scholarly journals Prophylaxis of thrombotic complications in a pregnant patients with prosthetic heart valves

2012 ◽  
Vol 61 (5) ◽  
pp. 10-24
Author(s):  
Aleksandr Davidovich Makatsariya ◽  
Viktoriya Omarovna Bitsadze ◽  
Dzhamilya Khizriyevna Khizroyeva ◽  
Vyacheslav Borisovich Nemirovskiy ◽  
Svetlana Vladimirovna Akinshina
Keyword(s):  
Heart Valve ◽  
Heart Valves ◽  
Anticoagulation Therapy ◽  
Mechanical Heart Valve ◽  
Prosthetic Heart Valves ◽  
Dose Selection ◽  
Heart Valve Prostheses ◽  
Adequate Dose ◽  
Thrombotic Complications ◽  
Valve Prostheses

In patients with prosthetic heart valves pregnancy and labor are associated with high risk. There are no established anticoagulation guidelines in pregnant women with mechanical heart valve prostheses. More often physiological hypercoagulable state during pregnancy can reveal acquired and/or inherited hemostasis abnormalities which were asymptotic before pregnancy. The presence in the history of patients the foetal loss syndrome, severe obstetric complications (severe preeclampsia, abruptio placenta, antenatal fetal death, feto-placental insufficiency), thrombosis events is an indication for the screening for genetic thrombophilia and antiphospholipid syndrome. The diagnosis of thrombophilia in patients with mechanical heart valve prostheses can explain the inefficiency of anticoagulation therapy, warfarin resistance, «floating» hemostasis markers and difficulties in adequate dose selection

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