Transcatheter mitral valve replacement in the degenerated mitral valve prosthesis implanted in the Dacron-collar-neo-mitral-ring due to severe mitral annulus calcification.

Background: Mitral annulus calcification (MAC) presents significant challenges in mitral valve (MV) surgery. We previously introduced a technique using a tubular Dacron prosthesis to create a neo-mitral ring, enabling prosthetic MV implantation while avoiding extensive MAC debridement. However, concerns remain regarding future valve degeneration. Case summary: A 60-year-old female with severe aortic valve (AV), tricuspid valve (TV), and MV disease, extensive MAC, and right coronary artery stenosis, along with terminal renal failure on chronic dialysis, underwent complex cardiac surgery. She received an AV replacement, MV replacement using our neo-mitral ring, TV repair, and an aorto-coronary bypass. Despite postoperative complications, she was discharged after 59 days.Three years later, after a kidney transplant, she returned 3.5 years post-surgery with prosthetic MV degeneration. A transapical transcatheter MV replacement was performed as a 'valve-in-valve' procedure. The perioperative course was mostly uneventful, except for sinus arrest requiring a pacemaker. She was discharged after 16 days and remained stable for 24 months without further interventions. Discussion: Severe MAC restricts MV prosthesis implantation due to reduced orifice size. Our neo-mitral ring technique enables implantation of a sufficiently large prosthetic MV in an intra-atrial position, preserving the left ventricular outflow tract. This facilitates future transcatheter valve interventions, offering an effective long-term solution for patients with severe MAC and complex comorbidities.