Emergency and Prophylactic Extracorporeal Membrane Oxygenation for Patients Undergoing Valve-in-Valve Transcatheter Aortic Valve Implantation With Small Surgical Bioprosthesis: A Report of Four Cases.

Mechanical circulatory support (MCS) using veno-arterial extracorporeal membrane oxygenation (VA-ECMO) is widely implemented as a rescue device in transcatheter aortic valve implantation (TAVI). Although prophylactic VA-ECMO (pECMO) in TAVI is preferable to emergency VA-ECMO (eECMO) in terms of overall survival, there is currently no consensus on the introduction criteria for pECMO. Here, we report four cases of eECMO and pECMO performed in valve-in-valve TAVI (ViV-TAVI) with a small surgical bioprosthesis to consider the validity of the current pECMO indications. In the two cases that were placed on eECMO, a 19 mm and 21 mm Carpentier-Edwards perimount bioprosthesis (CEP), a stented bioprosthetic valve, were sewn. After the transcatheter heart valve (THV) passed through the surgical aortic valve, acute aortic regurgitation developed, thus leading to hemodynamic instability requiring cardiopulmonary resuscitation, and therefore VA-ECMO was introduced. In the two cases using pECMO, 19 mm of CEP were sewn, and the THV was safely placed once MCS had been established. In all four cases, the patients were removed from VA-ECMO in the operating room following ViV-TAVI. The eECMO patients were discharged on postoperative days 12 and 20, while the pECMO patients were discharged on postoperative days 7 and 9, respectively. From our experience and based on the findings of some published reviews, ViV-TAVI with a small surgical bioprosthesis is considered to belong to a high-risk patient group demonstrating hemodynamic instability. The introduction of pECMO for such cases may therefore be an effective option for obtaining a better prognosis.