Stent deformation in a sutureless aortic valve bioprosthesis: a pilot observational analysis using imaging and three-dimensional modelling.

Abstract

The goal of this analysis of the Perceval aortic bioprosthesis was to investigate the ovalization/deformation of the Perceval prosthesis stent after implantation and its propensity for cusp dysfunction, fluttering, fibrosis and blockage. Between August 2014 and May 2019, a total of 134 patients (52% female) underwent aortic valve replacement with the Perceval bioprosthesis. We reconstructed three-dimensional models of the Perceval stent using thorax computed tomography scans for 16 patients employing the software Mimics (Materialise NV, Leuven, Belgium) and analysed the ovality of the stents. Radial force (RF) measurements were performed to compare the stiffness of the Perceval bioprosthesis to that of other valves. The three-dimensional reconstructions showed that all Perceval stents exhibited some degree of deformation and ovalization. Ovality in the annulus and commissure section of the Perceval stents ranged from 6.8% to 45% with mean values of 13.6% and 21.9%, respectively. The RF of the Perceval prosthesis was noticeably lower than that of the Edwards Intuity and several transcatheter aortic valve implantation devices. The stent adopted the preoperative shape of the aorta in the 2 patients for whom pre- and postoperative computed tomography data existed. The Perceval bioprostheses were deformed to different degrees in all analysed cases. The comparably low RFs might be an explanation for the propensity towards this deformation, which can lead to fluttering, a reduction of the cusps' mobility. This condition could potentially result in fibrosis as well as increased transvalvular pressure gradients and might be the cause for the increase in lactate dehydrogenase and the decrease in platelet count.