Correction of posteromedial papillary muscle displacement in repair of ischemic mitral regurgitation.

Abstract

BACKGROUND AND AIM OF THE STUDY: Ischemic mitral regurgitation is present in a substantial proportion of patients presenting for coronary revascularization. Although patients with even mild to moderate ischemic mitral regurgitation (IMR) have a poorer long-term outcome, mitral valve repair in these cases can be unreliable due to the posterior leaflet tethering that commonly occurs. The aim of this animal-based study was to evaluate a novel technique to effect such a repair. METHODS: IMR was produced in six greyhound dogs by tying off the circumflex coronary artery; a mitral valve repair was then performed on cardiopulmonary bypass (CPB). Two hitching sutures from the posteromedial papillary muscle (PPM) to the annulus were individually assessed using epicardial echocardiography when the dogs had been weaned off CPB. RESULTS: Acute dilatation of the heart with PPM displacement and mitral regurgitation were produced in this acute infarct model. Both hitching sutures shortened the distance from the free edge of the posterior leaflet to the PPM tip and reduced its displacement, with a resultant reduction in mitral regurgitation. CONCLUSION: This simple repair technique may be a useful adjunct to annuloplasty in the treatment of ischemic mitral regurgitation.