Novel Trigone-Based Sizing Method for Mitral Ring Annuloplasty.

Background: We devised a novel trigone-based sizing method, setting the trigones at one-quarter of the annular circumference, and used it for mitral annuloplasty in patients with mitral regurgitation (MR).

Methods: Between 1999 and 2017, 436 patients with degenerative (n = 192), nonischemic functional (n = 124), or ischemic (n = 120) MR underwent mitral valvuloplasty at our institution using an incomplete ring. The intertrigonal distance and prerepair and postrepair annular diameter were measured. Then the diameters predicted from body surface area, the intertrigonal distance, and the ratios of these diameters to observed data were computed. We investigated the influence of these measurements on MR recurrence, transmitral pressure gradient, and systolic anterior motion.

Results: Initial repair was successful in 433 patients (99%), but 3 patients with systolic anterior motion and MR required conversion to valve replacement. After 1, 5, and 10 years (mean follow-up, 6.3 years), the rate of freedom from grade 2 or higher recurrent MR was 96%, 92%, and 86% in the degenerative group, 99%, 97%, and 90% in the nonischemic functional group, and 95%, 90%, and 79%, respectively, in the ischemic group (P = .052). The observed/body surface area predicted diameter ratio was negatively correlated with the mean transmitral pressure gradient (mm Hg); 12.3 - 8.2 × (ratio) (R = -0.37, P < .001), despite a smaller ratio (<0.9) not being associated with less recurrence of MR. In the degenerative group, systolic anterior motion developed in 7 of 71 patients (10%) with an observed/intertrigonal distance predicted diameter ratio of less than 0.9 (P < .001).

Conclusions: Our trigone-based sizing method achieved satisfactory control of MR, while avoiding functional mitral stenosis and systolic anterior motion.