Valve embolization with a second-generation fully-retrievable and repositionable transcatheter aortic valve

Abstract

Valve embolization during transcatheter aortic valve implantation is a rare but potentially fatal complication of first generation transcatheter valves. As a result, second generation valves were designed to be fully retrievable and minimize this complication. We report a first case of embolization with a second-generation fully-retrievable and repositionable Lotus valve. In this case, the presence of severe left ventricular hypertrophy and a sigmoid septum may have contributed to prosthesis embolization with the initial 23mm Lotus valve. With the high implantation we performed with the 23mm Lotus valve, the septal bulging may have interfered with the high implanted Lotus valve, resulting in the "watermelon seeding" phenomenon, whereby the sigmoidal septum squeezes the valve out of place distally, in spite of the initial appearance of stability. With the 25mm Lotus valve, the lower implantation height, and the prosthesis oversizing, with greater radial strength, ensured greater stability of the valve. This case highlights the importance of meticulous pre-TAVI assessment of subvalvular geometry, irrespective of the use of newer devices that are repositionable and retrievable. The identification of severe hypertrophy in the subvalvular landing zone should be incorporated into the decision-making process with the possible selection of a self-expanding prosthesis and/or a lower implantation height of an over-sized prosthesis with the Lotus valve to ensure greater valve stability whilst accepting the higher likelihood of the requirement for permanent pacemaker implantation.

Keywords: Aortic stenosis; Lotus valve system; TAVI; TAVR; Valve embolization.