Loop technique for degenerative mitral regurgitation due to extended prolapse.

Purpose: Our study aims to examine the midterm outcomes of the loop technique for extended mitral valve (MV) prolapse patients.

Methods: From October 2008 to August 2020, we performed MV repairs in 407 patients with severe mitral regurgitation (MR). Follow-up ranged in duration from 287 to 2899 days (median, 872 days). The prolapse extensiveness (p-score) was determined based on the ratio of prolapsing segment's areas to whole area. We divided the whole MV into 10 segments (A1, A2 medial, A2 lateral, A3, P1, P2 medial, P2 lateral, P3, AC, and PC). Patients were categorized into three groups according to the p-score: simple (0.1-0.2), intermediate (0.3-0.4), and extensive (0.5-0.9).

Results: All patients underwent MV repair with the loop technique. The rates of freedom from significant (moderate to severe or severe) MR at 5 and 7 years after surgery were 91% and 91%, respectively. There were 252, 115, and 40 patients in simple group, intermediate group, and extensive group, respectively. The following were significantly increased in extended group: Barlow disease (23/40 patients, p < .001), the number of loops (p for trend < .0001), and the technique score (p for trend < .0001). The rates of freedom from significant MR at 7 years after surgery were 92% in simple group, 87% in intermediate group, and 94% in extended group, respectively (p = .995). Receiver-operating characteristic curves showed a postoperative mild MR with a sensitivity of 86% and a specificity of 68% for predicting significant MR recurrence.

Conclusions: MV repair using the loop technique was useful even in groups with extended prolapse.