Prevention of systolic anterior motion after mitral valve repair with an anterior leaflet valvuloplasty.

BACKGROUND AND AIM OF THE STUDY: Mitral valve repair (MVR) is the preferred method of treatment of the complex floppy mitral valve. Immediate repair failure, due to systolic anterior motion (SAM), is related to excessive anterior mitral valve leaflet (AMVL) tissue and/or anterior displacement of the leaflet coaptation point by the posterior mitral valve leaflet (PMVL) with resultant left ventricular outflow tract (LVOT) obstruction. Herein are reported the authors' experience of the AMVL valvuloplasty, a simple alternative to the sliding technique, to prevent post-MVR SAM.

METHODS: Between January 1996 and June 2003, elliptical excisions of the base of the AMVL and annuloplasty rings (nine Physio, 38 Seguin) were performed in 47 patients (mean age 66 years; range: 29-86 years). The surgical procedure included posterior mitral valve leaflet (PMVL) resection in 37 patients (80%), AMVL resection in 28 (61%), and transposition flaps in nine (19%). Four patients (8%) had a tricuspid valve repair, six (13%) had an aortic valve replacement, and nine (19%) had coronary bypass grafting. Intraoperative transesophageal echocardiography before and after MVR was performed to assess mitral valve anatomy, the presence and severity of mitral regurgitation (MR), and SAM.

RESULTS: There was no postoperative SAM. The severity of MR was reduced to trace or mild in all 47 patients. The mean AMVL length was 3.0 cm before and 2.2 cm after MVR, a tissue reduction of 27%. In those patients with a PMVL resection, the mean length was decreased from 1.95 cm to 1.5 cm, a tissue reduction of 23%. The mean annulus diameter decreased from 3.9 cm to 3.0 cm. The mean AMVL:PMVL ratio decreased from 1.6 to 1.4. The proportional size reduction of the AMVL compared to the PMVL was 17%. The mean coaptation point to annulus distance (CPAD) decreased from 1.1 cm to 0.9 cm. There was no 30-day in-hospital mortality.

CONCLUSION: The AMVL valvuloplasty eliminated postoperative SAM. There was both reduction of the AMVL surface area, limiting the excursion of the AMVL into the LVOT, and reduction of CPAD. This technique does not compromise the geometry of the mitral valve apparatus.