Severe Aortic Regurgitation of Early Degenerated Mitroflow Bioprosthesis

Valve-in-Valve transcatheter aortic valve implantation (ViV TAVI) is emerging as an effective therapeutic option for bioprosthetic valve failure. Recently, concern has been raised for early valve deterioration of Mitroflow (Sorin) aortic bioprosthesis, with the development of prevalent stenosis. We report cases of pure severe aortic regurgitation (AR) due to early and mid-term prosthesis degeneration. From June 2018 to October 2019, three patients were treated in our division for the new appearance of severe intraprosthetic regurgitation. Patient 1 (man, 85-year-old) and patient 3 (woman, 83-year-old) had a Mitroflow n. 25 and n. 21 implanted, respectively, in 2012 and 2013 for severe aortic stenosis. Patient 2, a 67-year-old woman with Marfan syndrome underwent a Mitroflow n. 25 implant in 2008 for severe AR and presented chronic type-B aortic dissection. Patient 1 was diagnosed with severe AR in the ambulatory setting, while the other patients presented acute heart failure, requiring inotrope support and high doses intravenous diuretics, and in case 3, temporary extracorporeal ultrafiltration. All patients appeared at high surgical risk and were successfully treated with ViV TAVI, through the right axillary artery in patient 2, and through the femoral artery in patients 1 and 3. Results were good at short- and mid-term follow-up. In conclusion, early and midterm bioprosthesis degeneration with the development of severe AR is a possible complication of the Mitroflow aortic valve. ViV TAVI has been confirmed as a safe and effective therapeutic option in our cases.