Assessing the Thrombogenic Potential of Heart Valve Prostheses: An Approach for a Standardized In-Vitro Method

Abstract

Purpose: Thrombogenic complications are still a main issue in the general performance of cardiovascular implants, especially heart valves. To date, the thrombogenic potential of those prostheses is pre-clinically assessed in time consuming animal studies with questionable evidence.

Methods: In this study, we present a new in-vitro method to assess and compare deficiencies of heart valve substitutes concerning their thrombogenic performance and locate initial clot formation under physiological conditions using porcine blood. Therefore, an athrombogenic pulse duplicator (THIA3) was developed that simulates the anatomic and hemodynamic conditions in the vicinity of the aortic valve. Validation of this tester was carried out with regard to hemodynamics, reproducibility and using positive and negative control valves and by comparison of clot locations with literature data from chronic animal trials with sheep using a St. Jude bileaflet valve.

Results: Validation of the tester showed quasi-physiological hemodynamics and reproducible clot formation. Identical clot formations were found comparing findings in vitro with chronic animal trials.

Conclusion: The THIA 3 has proven its suitability for valid, reproducible evaluation of thrombogenic potential of heart valves in a short period of time.

Keywords: Heart valve prostheses; In vitro testing; Tester validation; Thrombosis.