Transapical off-pump aortic valve-in-a-valve implantation in two elderly patients with a degenerated porcine bioprosthesis

Abstract

Re-operative heart-valve replacement is a high-risk procedure and even more so in elderly patients. Another option in high-risk patients with a degenerated aortic xenograft is the implant of a second aortic bioprosthesis using a transcatheter approach. We report two cases of patients with a severely degenerated porcine aortic bioprosthesis who were successfully treated by a transapical valve-in-a-valve implantation.

Transarterial Medtronic CoreValve System Implantation for Degenerated Surgically Implanted Aortic Prostheses

“…14 -22 The technique has recently been proposed in patients with SP failure, 23-31 mostly using a transapical approach with the balloon expandable valve prosthesis. 29,[32][33][34][35][36][37][38][39][40] To the best of our knowledge, this study reports the largest series of transarterial valve-in-valve implantation, using MCS for failed SP in high-risk patients.…”

Transcatheter Heart Valves for Failing Bioprostheses

“…Optimal THV function requires expansion of the valve to its nominal dimensions. 23,34 Underexpanded THVs may function suboptimally, demonstrating increased transvalvular pressure gradients and impaired coaptation of leaflets. 24 Leaflet distortion increases stress on leaflets and may result in THV premature failure.…”

“…Valve-in-valve implantation within 19-and 21-mm Carpentier-Edwards Perimount using available 23-mm THV size may result in high pressure gradients, depending on inner bioprosthetic stent diameter. 23 Lack of THV stent expansion to nominal dimensions resulted in THV leaflet distortion. Based on in vitro hemodynamics, 23-mm THV within 19-mm Perimount bioprostheses would be contraindicated clinically, but 20-mm THV would yield potentially acceptable but elevated mean gradients Ͼ20 mm Hg.…”

“…Because THV oversizing is necessary to achieve appropriate valve anchoring and decrease paravalvular regurgitation, a balance must be achieved to reduce the adverse impact of THV oversizing on valvular hemodynamics and long-term durability. 23 Patient-prosthesis mismatch may inevitably occur after valve-in-valve implantation in patients with small bioprostheses. The role of patient-prosthesis mismatch after standard AVR has been well described with respect to left ventricular mass regression, cardiac failure, and perioperative and longterm mortality.…”

“…No studies thus far report valve-in-valve implantation within 19-mm degenerated bioprostheses, which is important because currently available THVs would not be expected to be effective, based on experimental evidence (preclinical data in the online-only Data Supplement). 23,24 The first-in-man TAVI of 20-mm Sapien XT in the small annulus of native AS 25 may enable future treatment of select 19-mm bioprostheses, albeit with elevated gradients, based on experimental results. 26 Recently, German Heart Center, Munich, reported the largest case series of TAVI within failing aortic bioprostheses.…”