Mitral Annular Disjunction in Advanced Myxomatous Mitral Valve Disease: Echocardiographic Detection and Surgical Correction

Mitral annular disjunction is a structural abnormality of the mitral annulus fibrosus described by pathologists in association with mitral leaflet prolapse and defined as a separation between the atrial wall-mitral valve (MV) junction and the left ventricular attachment allowing for hypermobility of the MV apparatus. The transesophageal echocardiographic characteristics of this abnormality have not been previously described. In patients undergoing MV repair for myxomatous MV degeneration and evaluated using a standardized transesophageal echocardiographic protocol, annular disjunction (mean value 10 ± 3 mm) was seen at the base of the posterior leaflet in 98% of patients with advanced, and in 9% of patients with mild/moderate MV degeneration. There was a significant correlation between the magnitude of disjunction and the number of segments with prolapse/flail (r = 0.397, P = .001). We found annular disjunction to be a common component of MV apparatus in advanced MV degeneration. Its recognition on transesophageal echocardiography is important to facilitate optimal MV repair. The modification of the repair technique allows surgical correction of the annular disjunction, which seems to optimize long-term results in these challenging cases.