Preservation of Mobility of the Posterior Mitral Leaflet After Mitral Valve Repair With Neochordae Using Loop Technique

Background: Recently, the loop technique has been standardized for mitral valve repair, with excellent long-term outcomes reported. This study thus analyzed whether the loop technique could preserve mitral leaflet mobility on trans-thoracic echocardiography. Methods and Results: Among 367 concomitant patients who underwent mitral valve repair at Keio University Hospital between January 2007 and December 2014, 304 patients had a prolapse of the posterior leaflet. Of these, 84 cases assessed on echocardiography were retrospectively analyzed for this study. These patients were divided into 4 groups based on the procedure used: (1) group L1 (n=28), loop technique alone; (2) group L2 (n=14), loop technique with resection and suture; (3) group L3 (n=33), loop technique with plication of indentation; and (4) group R (n=9), resection and suture alone. The mean postoperative mobile posterior mitral leaflet (PML) angles in groups L1 and L2 (39.3+/-16.0 degrees, 37.3+/-16.0 degrees) were significantly larger than those in groups L3 and R (18.8+/-15.7 degrees, 15.3+/-15.7 degrees), respectively (P<0.01). Ring size, age, and mobile PML angle had a statistically significant correlation with the postoperative mean mitral valve pressure gradient (P<0.05). Conclusions: The loop technique preserved PML mobility and enabled implantation of a larger ring, resulting in a reduced mean mitral valve pressure gradient.