A Biocompatible Flow Chamber to Study the Hemodynamic Performance of Prosthetic Heart Valves

Abstract

The goal of this study was to design, fabricate, and characterize a biocompatible flow chamber to study the performance of artificial heart valves. The system consists of a testing fluid chamber and a water chamber (separated by a latex diaphragm), following the design of a left ventricular assist device. Two St. Jude bileaflet mechanical heart valves were placed oppositely in the testing fluid chamber to control flow direction. The flow rate of the testing fluid chamber was set at 5.6 L/min, with a stroke volume of 80 ml. The performance of the system was examined through three-dimensional numerical simulation and in vitro experiments with whole blood and washed platelets. Hemolysis was measured with whole blood using a spectrophotometer. Platelet activation was measured by platelet surface P-selectin expression using flow cytometry. The three-dimensional computational fluid dynamics model demonstrated that the flow field in the chamber was laminar and physiological. Results from in vitro experiments indicated that the flow conditions in the chamber did not induce hemolysis or platelet activation with the presence of St. Jude heart valves. Overall, the flow chamber can provide a feasible environment to study the hemodynamic performance of artificial heart valves.

Use of Computational Fluid Dynamics to Analyze Blood Flow, Hemolysis and Sublethal Damage to Red Blood Cells in a Bileaflet Artificial Heart Valve

“…Failure of a suture with the valve pulling away from the surrounding tissue, dehiscence, is yet another problem [22] leading to hemolysis. While clinical studies show a prevalence of subclinical hemolysis (with a low incidence of hemolytic anemia or clinically severe hemolysis) in valve replacement patients [23][24][25], current in-vitro and CFD research into hemolysis damage are still measuring and predicting damage to RBCs from notable amounts of hemolysis caused by artificial heart valves [26][27][28][29].…”

Evaluation of Dysprosia Aerogels as Drug Delivery Systems: A Comparative Study with Random and Ordered Mesoporous Silicas

“…The plasma hemoglobin concentration was determined by measuring the light absorbance of the substrate reagent at 600 nm. 67 2.3.2. Aggregation Testing.…”

“…Activator reagent (H 2 O 2 , 200 μL) was added so that hemoglobin in the samples could activate the substrate reagent and change the substrate color. The plasma hemoglobin concentration was determined by measuring the light absorbance of the substrate reagent at 600 nm …”

Emerging Trends in Heart Valve Engineering: Part III. Novel Technologies for Mitral Valve Repair and Replacement

“…Once built, ex vivo biocompatible flow chambers can also be used to test the performance of prosthetic heart valves. 66 Until more durable valves are introduced, the mechanical heart valves will remain the first choice for younger patients. In the next few years, the mechanical heart valve field should continue evolving from efforts to optimize hemodynamics, testing devices, and surface coatings.…”