Sutureless aortic valve replacement: a theoretical analysis of the effective orifice area in comparison with stented valves

Abstract

Objective: Sutureless aortic valve replacement has recently been introduced as an alternative to conventional surgery to minimize the operative risk in elderly patients, shortening the cardiopulmonary bypass time and enhancing the minimally invasive approach. The aim of our study is to demonstrate that the sutureless bioprosthesis, compared to a conventional sutured prosthesis, has a corresponding larger effective orifice area, resulting in a better hemodynamic performance of the left ventricle. Materials and methods: In this prospective observational study, between January 2014 and September 2015, among our population of 37 sutureless aortic valve replacements, we examined 17 patients (sutureless, A group), in which a second measurement with a standard stented valve sizer has been performed during surgery. As a control group, we analyzed 10 additional aortic valve replacements who received conventional stented bioprosthesis (sutured, B group), in which an additional measurement with the sutureless sizer has been used to compare size and effective orifice areas differences between the sutureless and the sutured valves for any given annulus. Results: The size of the implanted bioprosthesis was 23,1 ± 1,9 mm and 23 ± 1,6 mm for the sutureless and sutured groups, respectively. In both groups, there were significative differences between the effective orifice areas of the implanted and the control sized prosthesis, always in favour of the sutureless valve (sutureless, A group: 2,6 ± 0,3 vs 1,4 ± 0,0 cm2, p < 0,001; sutured, B group: 1,5 ± 0,2 vs 2,9 ± 0,3 cm2, p < 0,001). Conclusions: Previous studies compared nominal sizes regardless of the effective orifice areas. For the first time, we analyzed the areas of the sutureless versus sutured bioprosthesis. For every single patient considered, the effective orifice area was significantly larger with the sutureless rather than with the sutured bioprosthesis that could fit. In sutureless aortic valve replacements, the benefits go far beyond the cardiopulmonary bypass and cross-clamp time reduction, providing larger areas and less risk of patient-prosthesis mismatch.