Background: Mitral valve (MV) repair for posterior mitral leaflet (PML) prolapse has proven excellent results. The loop technique, which involves insertion of polytetrafluoroethylene neochordae while preserving the native PML tissue, was developed to facilitate MV repair through a minimally invasive approach. The aim of this study was to assess the medium-term results of the loop technique in comparison with the widely adopted leaflet resection technique for repair of isolated PML prolapse.
Methods: Between March 1999 and January 2008, a total of 1,708 patients underwent minimally invasive MV repair. Six hundred and seventy patients (39.2%) had isolated PML prolapse and were treated with either the loop technique (n = 317) or the leaflet resection (n = 353) technique, according to surgeon preference. Mean follow-up time was 2.8 +/- 2.2 years, and follow-up was 99% complete.
Results: Early postoperative echocardiography showed a significantly larger mitral orifice area (3.3 +/- 0.3 cm(2) versus 3.0 +/- 0.8 cm(2), p < 0.001) and lower mean pressure gradient (2.7 +/- 1.7 mm Hg versus 3.1 +/- 1.7 mm Hg, p = 0.03) after implantation of loops. Other perioperative outcomes were similar for the two groups of patients. Freedom from reoperation at 5 years was significantly higher after the loop technique (98.7%, 95% confidence interval [CI]: 96.7% to 99.5%) when compared with leaflet resection (93.9%, 95% CI: 90.7% to 96.1%, log-rank p = 0.005). Cox regression analysis revealed that implantation of a flexible, incomplete band was an independent predictor of reoperation (hazard ratio 6.2, 95% CI: 1.3 to 110.7), whereas use of leaflet resection had a nonsignificant trend toward an increased reoperation rate (hazard ratio 2.6, 95% CI: 0.9 to 9.1). Reoperation for excessive systolic anterior motion did not occur in any loop patient.
Conclusions: Both the loop technique and conventional leaflet resection yield excellent results for repair of isolated PML prolapse. The technical ease of performing the loop technique through a minimally invasive approach, however, makes this method a particularly valuable alternative for MV repair surgery.