Left ventricular outflow tract obstruction after mitral valve repair. Results of the sliding leaflet technique

Left ventricular outflow tract obstruction (LVOTO) occurs in 4% to 5% of patients after prosthetic ring mitral valve repair. Major anatomic factors incriminated in the genesis of LVOTO include degenerative mitral valve insufficiency with excess leaflet tissue, nondilated left ventricular cavity, and narrow mitro-aortic angle. We have previously reported a 14% incidence of LVOTO after prosthetic ring mitral valve repair in this high-risk group of patients. Serial echo Doppler studies demonstrated an overlapping and/or inversion of the left ventricular functional compartments generating systolic anterior motion of the posterior leaflet and paradoxical opening (eversion) of the anterior leaflet. In an attempt to eliminate LVOTO after mitral valve repair, a new surgical procedure was developed in 1988 by Carpentier: the sliding leaflet technique, which reduces the height of the posterior leaflet. The purpose of this study was to analyze the results of the new technique in terms of the occurrence of LVOTO:

Eighty-two patients undergoing prosthetic ring mitral valve repair between 1988 and 1991 and identified as high risk for LVOTO were operated on using the sliding leaflet technique. There were 52 men and 30 women. Ages ranged from 28 to 75 years. The surgical techniques used included prosthetic ring annuloplasty (n = 82), leaflet resection (n = 82), chordal shortening or transposition (n = 36), and other (n = 19). Intraoperative and/or immediate postoperative echo Doppler studies were obtained in all cases. Two patients (2.4%) died, and 2 (2.4%) required reoperation. Nonsignificant LVOTO was identified in 2 cases (2.4%), in whom instantaneous maximal subaortic gradients were 20 and 18 mm Hg, respectively.

This study was not done on a concomitant series of patients but on patients with the same type of pathology. It demonstrates that (1) the sliding leaflet technique eliminates significant LVOTO in the high-risk patients; (2) the sliding leaflet technique is associated with a low mortality; and (3) no reoperations for mitral insufficiency were required in this series.