Anatomic reconstruction in degenerative mitral valve bileaflet prolapse: long-term results.

BACKGROUND

Degenerative mitral valve (MV) bileaflet prolapse (DMVBP) is recognized as one of the most complex lesions to be treated by reconstructive surgery. In the present study, we report our long-term results with reconstructive surgery for DMVBP.

METHODS

From 2000 to 2011, 140 patients with MV regurgitation due to DMVBP were treated at our institution. Mean age was 56.4±14.5 years (range 16 to 84). Of the 140 study patients, 24 (17%) were in functional class I, 48 (34%) in class II, 60 (43%) in III, and 8 (6%) in class IV of the New York Heart Association. The MV leaflets were reconstructed without using prosthetic material, maintaining the normal shape and dimension of the valve ring and inter-papillary distance. The standard surgical procedure included the excision of the most elongated or ruptured chordae area of the posterior leaflet, with subsequent transposition of second-order chordae from the posterior leaflet to the most elongated or ruptured chordae area of the anterior leaflet. This procedure was performed in 123 patients. A para-commissural edge-to-edge was performed in 16 patients and a triangular resection of the anterior MV leaflet in 1 patient. The posterior leaflet was reconstructed with different techniques: a longitudinal suture of the annulus and residual scallops in 86 patients, a Z-plasty suture in 51 and a sliding suture of the residual posterior scallops in 3 patients. A posterior trygon-to-trygon annuloplasty was performed with an autologous pericardium strip in all patients. During follow-up, serial echocardiograms were obtained once a year.

RESULTS

There were no hospital deaths. Mean follow-up was 6.42±3.1 years. Of the 140 study patients, 7 developed severe (3+), 10 moderate (2+) and 18 mild (1+) MV regurgitation. Two patients were reoperated within 6 months; 1 after 8 years and 1 after 10 years for recurrence of severe MV regurgitation. At 12 years after the initial surgical procedure, overall survival was 95.8%, freedom from MV re-intervention was 91.8% and freedom from late recurrence of 2+ or greater MV regurgitation was 78.7%. All patients had a satisfactory residual MV area, leaflets motion, and inter-papillary muscle distance. No patient developed left ventricular outflow tract obstruction.

CONCLUSIONS

Our results confirm the effectiveness of anatomic reconstruction in the DMVBP. Survival rate after mitral valve repair is identical to that of the general population when surgery is performed in asymptomatic or pauci-symptomatic patients; the identification of this kind of patient is required followed by a therapeutic strategy for early surgery. This management approach in patients with DMVBP leads to optimal long-term results of MV repair.