The papillary muscle sling for ischemic mitral regurgitation

Abstract

Objective: Our objective was to evaluate long-term stability of mitral repair and reverse remodeling in patients with severe ischemic left ventricular dysfunction and functional mitral regurgitation.

Methods: Since June 2000, a total of 37 patients with ischemic functional mitral regurgitation have benefited from a double-level mitral repair that comprises an intraventricular peripapillary muscle sling completed by a classic intra-atrial mitral annuloplasty ring (mean age, 56 years; left ventricular end-diastolic diameter, 70 +/- 0 mm; left ventricular end-systolic diameter, 55 +/- 5.6 mm; ejection fraction, 15% to 45%; pulmonary hypertension > 60 in all patients; all were in New York Heart Association class III-IV). All patients had both papillary muscles encircled with a 4-mm polytetrafluoroethylene tube, correcting their lateral and downward displacement. Annuloplasty rings were moderately undersized or normal. Efficiency was evaluated on mitral stability, ventricular parameters, and functional status. According to the Leyden algorithm based on preoperative end-diastolic and end-systolic left ventricular diameters, only a minority of our patients were expected to experience reverse remodeling.

Results: Regurgitation is none to trivial in 31 and mild to moderate in 4. Follow-up (3-84 months; mean, 55 +/- 22 months) shows stability of all initially successful double-level mitral repairs. Follow-up beyond 1 year shows improvements in ventricular diameters (56 +/- 5 mm), ejection fraction (49 +/- 6), volume (130 +/- 10 mL), and sphericity index (0.55). Two patients died during follow-up and 1 underwent transplantation.

Conclusion: Reapproximating the papillary muscles has an immediate effect on mitral leaflet mobility by suppressing the tethering resulting from displacement of the papillary muscles. It has an effect in preventing recurrent mitral regurgitation by avoiding further papillary muscle displacement. In this cohort of severely disabled patients, reverse remodeling can be expected with the double-level repair.