Patient‐specific in vitro testing for evaluating TAVR clinical performance—A complementary approach to current ISO standard testing. Issue 4 (7th December 2020)

• Record Type: Journal Article
• Authors: Kovarovic, Brandon J.; Rotman, Oren M.; Parikh, Puja; Slepian, Marvin J.; Bluestein, Danny
• Is Part Of: Artificial organs. Volume 45:Issue 4(2021)
• Page Start: E41
• Page End: E52
• Publication Date: 2020-12-07
• Subjects: calcific aortic valve disease -- in vitro hemodynamic testing -- ISO 5840 -- patient‐specific testing -- transcatheter aortic valve replacement; Artificial organs -- Periodicals; 617.956
• DOI: 10.1111/aor.13841
• Languages: English
• ISSNs: 0160-564X

Abstract

Abstract: Following in vitro tests established for surgical prosthetic heart valves, transcatheter aortic valves (TAV) are similarly tested in idealized geometries—excluding effects that may hamper TAVR performance in situ. Testing in vitro in pulse duplicator systems that incorporated patient‐specific replicas would enhance the testing veracity by bringing it closer to the clinical scenario. To that end we compare TAV hemodynamic performance tested in idealized geometries according to the ISO standard (baseline performance) to that obtained by testing the TAVs following deployment in patient‐specific replicas. Balloon‐expandable ( n = 2) and self‐expandable ( n = 3) TAVs were tested in an idealized geometry in mock‐circulation system (following ISO 5840‐3 guidelines) and compared to the measurements in a dedicated mock‐circulation system adapted for the five patient‐specific replicas. Patient‐specific deployments resulted in a decline in performance as compared to the baseline idealized testing, as well as a variation in performance that depended on the design features of each device that was further correlated with the radial expansion and eccentricity of the deployed TAV stent (obtained with CT‐scans of the deployed valves). By excluding the deployment effects in irregular geometries, the current idealized ISO testing is limited to characterize the baseline device performance. Utilizing patient‐specific anatomic contours provides performance indicators under more stringent conditions likely encountered in vivo. It has the potential to enhance testing and development complementary to the ISO standard, for improved TAV safety and effectiveness. Abstract : In vitro testing of transcatheter aortic valves (TAV) are tested in idealized geometries, whereas this study incorporated patient‐specific replicas to emulate the clinical scenario. The TAV hemodynamic performance tested in ISO standard idealized geometries is compared to the performance in patient‐specific replicas. Patient‐specific deployments resulted in a performance reduction and a variation in performance dependent on the TAV stent design, radial expansion, and eccentricity. Utilizing patient‐specific anatomies enhances testingand development complementary to the ISO standard, for improved TAV safety.