Thorac Cardiovasc Surg 2015; 63 - OP40
DOI: 10.1055/s-0035-1544292

Assessment of the Hydrodynamic Function of TAVI Prostheses Implanted in Bioprostheses

M. Kütting 1, Ghalati P. Farhadi 1, C. Schmitz 1, M. Utzenrath 1, S. Egron 1, A. Sedaghat 2, B. Fujita 3, S. Ensminger 3, U. Steinseifer 1
  • 1Helmholtz-Institut RWTH Aachen, Cardiovascular Engineering, Aachen, Germany
  • 2Medizinische Klinik II, Universität Bonn, Kardiologie, Bonn, Germany
  • 3Klinik für Thorax- und Kardiovaskularchirurgie, HDZ NRW, Bad Oeynhausen, Germany

Objectives: Bioprostheses are currently and have been for the last decades favored over mechanical heart valve prostheses, but are prone to early device failure. Hence, valve-in-valve implantation to restore valvar function in dysfunctional bioprostheses is becoming part of clinical routine. This study seeks to investigate the hydrodynamic function of TAVI prostheses in bioprostheses.

Methods: Four different TAVI prostheses (Edwards Sapien XT 23 mm and 26 mm, Medtronic CoreValve 26 mm and 29 mm) were matched to bioprostheses (Medtronic Mosaic, Edwards Perimount, St. Jude Trifecta, Vaskutec Aspire) for which they are deemed suitable for implantation according to manufacturer guidelines or the Valve-in-Valve app. The prostheses were positioned and expanded according the recommendations given in the Valve-in-Valve app. Using a left heart simulator, the hydrodynamic performance of the bioprosthesis-TAVI prosthesis pairing was assessed at three different physiological flow conditions (cardiac output: 3l/min, 5l/min and 8l/min).

Results: Gradients for all bioprosthesis-TAVI prosthesis pairings showed an average of 11.5 mmHg for 5L/min of cardiac output (5.4 mmHg at 3l/min, 16.7 mmHg at 8l/min). Higher gradients were recorded in bioprostheses with small inner diameters. In cases were the recommendations for choosing a certain size TAVI prosthesis were not clear, the larger size TAVI prosthesis led to higher leakage and closure volumes. The mean insufficiency was 5.32% of the stroke volume for 5l/min of cardiac output (4.24% for 3l/min, 3.04% for 8l/min). Direct comparisons of the Sapien XT and CoreValve in identical bioprosthesis models showed comparable gradients, while leakage differed, with the Sapien XT showing better seal in an Edwards Perimount and the CoreValve showing better seal in a St. Jude Trifecta.

Conclusions: Implantation of TAVI prostheses into dysfunctional bioprosthesis is a hydrodynamically viable option of restoring valvar function. A better understanding of the interaction between TAVI prostheses and degenerated bioprostheses will impact prosthesis type and sizing choices and further benefit the outcome of patients undergoing valve-in-valve implantations.