High-pressure balloon fracturing of small dysfunctional Mitroflow bioprostheses facilitates transcatheter aortic valve-in-valve implantation

AIMS: Transcatheter valve-in-valve (VIV) implantation is usually discouraged in small surgical tissue valves. We report our first ten cases of fracturing small dysfunctional Mitroflow bioprostheses by high-pressure balloon dilatation to increase the internal diameter of the surgical valve before VIV (BF-VIV). METHODS AND RESULTS: BF-VIV was performed in 10 patients (mean age 84±4 years) with failing Mitroflow valves size 19 mm (n=3, threshold of fracture 15 atm) and 21 mm (n=7, threshold of fracture 13 atm). An Edwards SAPIEN 3 or XT 20 mm or 23 mm transcatheter valve was implanted inside the fractured Mitroflow bioprosthesis. The procedure improved aortic valve area (0.7±0.3 vs. 1.1±0.3 cm2, p=0.001), reduced peak aortic valve gradient (66±27 vs. 29±7 mmHg, p=0.002), resolved aortic regurgitation and improved patients' NYHA functional class (p=0.005). One patient had a minor stroke with complete resolution of symptoms and another patient required a pacemaker due to AV block. All patients were still alive at the end of follow-up (438±255 days). CONCLUSIONS: Initial experience with transcatheter BF-VIV suggests that this method is feasible and safe, and that it improves aortic valve haemodynamics and clinical functional capacity. BF-VIV is a promising alternative to repeat surgery in patients with small failing Mitroflow bioprostheses.