In vivo degradation of silicone rubber poppets in prosthetic heart valves

1976 ◽  
Vol 10 (3) ◽  
pp. 471-481 ◽  
Author(s):  
Edward F. Cuddihy ◽  
Jovan Moacanin ◽  
E. John Roschke ◽  
Earl C. Harrison
Keyword(s):  
Silicone Rubber ◽  
Heart Valves ◽  
Prosthetic Heart Valves ◽  
In Vivo Degradation

Modeling of Tissue Fatigue Damage in Bio-Prosthetic Heart Valve

2011 ◽  
Author(s):  
Caitlin Martin ◽  
Wei Sun
Keyword(s):  
Fatigue Damage ◽  
Heart Valve ◽  
Anticoagulant Therapy ◽  
Heart Valves ◽  
Prosthetic Heart Valve ◽  
Bovine Pericardium ◽  
Prosthetic Heart Valves ◽  
Mechanical Valves ◽  
In Vivo Degradation

Bio-prosthetic heart valves (BHVs) with leaflets made of glutaraldehyde-treated bovine pericardium (GLBP), have been used extensively to replace diseased heart valves. BHVs display superior hemodynamics to mechanical valves and eliminate the need for anticoagulant therapy; however, they exhibit poor durability resulting from in vivo degradation and fatigue damage of the leaflets.

scholarly journals SIBS triblock copolymers in cardiac surgery: in vitro and in vivo studies in comparison with ePTFE

2020 ◽  
Vol 21 (4) ◽  
pp. 67-80
Author(s):  
M. A. Rezvova ◽  
E. A. Ovcharenko ◽  
P. A. Nikishev ◽  
S. V. Kostyuk ◽  
L. V. Antonova ◽  
...  
Keyword(s):  
Cell Adhesion ◽  
Heart Valves ◽  
Ex Vivo ◽  
Calcium Content ◽  
Positive Control ◽  
Prosthetic Heart Valves ◽  
Solution Casting Method ◽  
Cell Adhesion And Proliferation

Implantation of polymeric heart valves can solve the problems of existing valve substitutes – mechanical and biological. Objective: to comprehensively assess the hemocompatibility of styrene-isobutylene-styrene (SIBS) triblock copolymer, synthesized by controlled cationic polymerization in comparison with expanded polytetrafluoroethylene (ePTFE) used in clinical practice. Materials and methods. SIBS-based films were made by polymer solution casting method; in vitro biocompatibility assessment was performed using cell cultures, determining cell viability, cell adhesion and proliferation; tendency of materials to calcify was determined through in vitro accelerated calcification; in vivo biocompatibility assessment was performed by subcutaneous implantation of rat samples; hemocompatibility was determined ex vivo by assessing the degree of hemolysis, aggregation, and platelet adhesion. Results. The molecular weight of synthesized polymer was 33,000 g/mol with a polydispersity index of 1.3. When studying cell adhesion, no significant differences (p = 0.20) between the properties of the SIBS polymer (588 cells/mm2) and the properties of culture plastics (732 cells/mm2) were discovered. Cell adhesion for the ePTFE material was 212 cells/mm2. Percentage of dead cells on SIBS and ePTFE samples was 4.40 and 4.72% (p = 0.93), respectively, for culture plastic – 1.16% (p < 0.05). Cell proliferation on the ePTFE surface (0.10%) was significantly lower (p < 0.05) than for the same parameters for SIBS and culture plastic (62.04 and 44.00%). Implantation results (60 days) showed the formation of fibrous capsules with average thicknesses of 42 μm (ePTFE) and 58 μm (SIBS). Calcium content in the explanted samples was 0.39 mg/g (SIBS), 1.25 mg/g (ePTFE) and 93.79 mg/g (GA-xenopericardium) (p < 0.05). Hemolysis level of red blood cells after contact with SIBS was 0.35%, ePTFE – 0.40%, which is below positive control (p < 0.05). Maximum platelet aggregation of intact platelet-rich blood plasma was 8.60%, in contact with SIBS polymer – 18.11%, with ePTFE – 22.74%. Conclusion. In terms of hemocompatibility properties, the investigated SIBS polymer is not inferior to ePTFE and can be used as a basis for development of polymeric prosthetic heart valves.

In Vivo Observation of Cavitation on Prosthetic Heart Valves

ASAIO Journal ◽  
1996 ◽  
Vol 42 (5) ◽  
pp. M550-554 ◽  
Author(s):  
CONRAD M. ZAPANTA ◽  
DAVID R. STINEBRING ◽  
DEBORAH S. SNECKENBERGER ◽  
STEVEN DEUTSCH ◽  
DAVID B. GESELOWITZ ◽  
...  
Keyword(s):  
Heart Valves ◽  
Prosthetic Heart Valves

Statistical Analysis of Longevity of Prosthetic Aortic Valves

1976 ◽  
Vol 43 (1) ◽  
pp. 2-7 ◽  
Author(s):  
D. N. Ghista ◽  
Y. K. Lin
Keyword(s):  
Heart Valves ◽  
Prosthetic Heart Valve ◽  
Fatigue Properties ◽  
Prosthetic Heart Valves ◽  
Aortic Valves ◽  
Damage Rate ◽  
Design Charts ◽  
Physiological Fluid ◽  
Fluid Environment

The analysis and procedure for obtaining the average fatigue damage rate, and hence a measure of longevity, of a prosthetic heart valve is presented. Design charts are developed to obtain measures of longevity of prosthetic heart valves, for various values of valve geometry characterizing parameter, valve’s in vivo pressure loading characteristics and the fatigue properties of the valve material. Such design charts can be updated when more reliable information about the fatigue properties of valve material (in a physiological fluid environment) becomes available.

An Experimental Study of the Flow-Induced Mass Transfer Distribution in the Vicinity of Prosthetic Heart Valves

1981 ◽  
Vol 103 (1) ◽  
pp. 1-10 ◽  
Author(s):  
F. L. Galanga ◽  
J. R. Lloyd
Keyword(s):  
Mass Transfer ◽  
Experimental Study ◽  
Heart Valves ◽  
Electrochemical Techniques ◽  
Reynolds Numbers ◽  
In Vivo Studies ◽  
High Mass ◽  
Prosthetic Heart Valves ◽  
Disk Valve

An experimental study of the flow-induced mass transfer distribution in the vicinity of a model disk valve and a ball valve was conducted using electrochemical techniques. Reynolds numbers ranged from 1000 to 6000, which are characteristic of physiologic conditions. Local instantaneous and time average data are presented. It was found that the flow-induced mass transfer distribution was high in regions of both low and high shear. It was also demonstrated that the fluctuations in the mass transfer to the wall of the test section around the valve are significantly affected by valve design. The regions of high mass transfer measured in this study were found to correlate very closely to regions where thrombus formations have been documented in in-vivo studies.

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