Transcather Mitral Valve-in-Valve Replacement: The New Frontier in Heart Valve Therapy

Introduction: Surgical valve replacement is not always feasible in patients with severe mitral regurgitation from a failing bioprosthetic valve or severe mitral annular calcification. Off-label use of transcatheter aortic valves has been described in the literature as a possible method of valve replacement for this patient population. We review the literature on this practice as well as present two cases of successful implantation of the Sapien XT valve in the mitral position. Case Series: Two patients were selected for implantation of a transcatheter valve in the mitral position due to their prohibitively high surgical risk. A transapical approach was used. One of the patients utilized venous-arterio extracorporeal mechanical oxygenation. The procedure was performed in a hybrid OR under general anesthesia. Successful implantation of both valves was achieved with survival beyond 30 days in each patient. Discussion: There have been 113 cases of valve-in-valve and valve-in-ring procedures described in the literature. There have also been 11 cases of implantation into a native valve with severe mitral annular calcification. Both of these methods are feasible, however the architecture of the native mitral valve annulus is best suited for a dedicated mitral prosthesis. These dedicated transcatheter mitral valves are undergoing early safety and feasibility trials. Conclusion: There has been early success with utilizing transcatheter aortic valves in the mitral position; however this practice will likely be temporary as dedicated transcatheter mitral valves progress through their development. Schilling J and Islam AM* Department of Medicine, Baystate Medical Center, USA Islam AM, et al. Clinics in Surgery Thoracic Surgery Remedy Publications LLC., | http://clinicsinsurgery.com/ 2016 | Volume 1 | Article 1051 2 proceed despite the risks. The first patient was an 88 year-old male with chronic atrial fibrillation with pacemaker insertion for tachy-brady syndrome, preserved left ventricular ejection fraction, and severe mitral regurgitation due to a degenerated (#33 porcine valve) mitral valve bioprosthesis placed 11 years ago. Now he presents with Class IIIIV NYHA heart failure symptoms. Coronary arteries were normal. Pulmonary artery systolic pressures were 65-70mmHg. He was deemed to be inoperable due to severe comorbidities, frailty and cachexia and a 30-day risk of surgical mortality above 12%. The second patient was a 77 year-old female with history of bioprosthetic mitral valve replacement (#29 tissue valve) for rheumatic mitral regurgitation, tricuspid valve ring annuloplasty, CABG x2, biatrial cryomaze, and left atrial appendage ligation 18 months prior. She presented to an outside facility with recurrent NYHA Class III heart failure symptoms where cardiac catheterization showed patent grafts and a PA pressure of 70/25mmHg. Subsequently, she was transferred to our facility and was found to have severe eccentric mitral valvular regurgitation through the bioprosthetic valve with severe biventricular dysfunction. Her left ventricular ejection fraction was 30% without regional wall motion abnormalities. A malfunctioning and restricted leaflet resulting in severe eccentric mitral regurgitation was noted on the transesophageal echocardiogram. She was also felt to be inoperable. It was decided that she should be placed on transfemoral veno-arterial cardiopulmonary bypass for a short period intraoperatively as she would not likely tolerate rapid ventricular pacing required for valve placement and closure of the left ventriculotomy due to severe left and right ventricular dysfunction.