Mid-term results of mitral valve replacement and repair: current clinical experience, technical aspects, and risk factor analysis

Aim: we evaluated the short- and mid-term results of mitral valve replacement (MVR) and mitral valve repair (MV-repair). Methods: in total, 168 patients (mean age 67 ± 11 years) underwent MVR (n = 104) and MV-repair (n = 64). To treat posterior leaflet disease, MV-repair techniques included triangular or quadrangular resection (n = 38), P1-P2 plication (n = 4), side-to side P1-P2 (n = 1), posterior-medial commissure-plasty (n = 1), and annuloplasty (n = 20). A prosthetic ring was implanted in all patients. In the presence of degenerative disease involving the anterior leaflet, extensive myxomatous and/or prolapsing pathology of the entire valve, and/or rheumatic and endocarditis degeneration, surgical orientation was to perform MVR directly. When possible, the sub-valvular apparatus with its papillary muscle was partially preserved. The mean follow-up was 38 ± 22 months. Results: operative mortality (0.96% vs. 1.56%) and six-year survival (94% vs. 100%) were similar in MVR and MV-repair. The only independent predictor of late survival was advanced age at the operation (79.2 years vs. 66.4 years; P = 0.012). Freedom from redo-operation was 100%. Partial preservation of the sub-valvular apparatus with its papillary muscle during MVR allowed postoperatively a better left ventricular function with similar values achieved with MV-repair (P = 0.05), and it was a protective factor against the development of left ventricular dysfunction during follow-up (P = 0.01). Conclusion: MVR and MV-repair are associated with satisfactory results in the short and medium term. MV-repair to treat posterior leaflet disease is associated with a stable and long-lasting result; MVR allows equally satisfactory results in the presence of more extensive and more complex mitral valve disease. Partial preservation of the subvalvular apparatus favors a better left ventricular systolic function.