Background and aim of the study: Congenital hammock mitral valves are rarely discovered in adulthood. The case is presented of a 29-year-old woman in NYHA functional class III and with markedly depressed left ventricular (LV) function, who underwent surgery for severe mitral regurgitation.
Methods and results: Preoperative transthoracic echocardiography showed grade 3+/4 mitral regurgitation due to restricted leaflet motion, and an almost immobile posterior leaflet due to the attachment of fibrotic chordae high on the posterior LV wall. At surgery, limited motion of both leaflets and partial agenesis of the posterior leaflet were found. The valve was repaired by resecting the posterior leaflet defect, mobilizing the papillary muscle, and then widening the posterior leaflet. Postoperative echocardiography revealed no further mitral regurgitation, and the valve remained competent despite a postoperative episode of cardiac decompensation.
Conclusion: Hammock mitral valve repair is a highly challenging procedure, particularly in patients presenting with LV dilatation. The greatest degree of leaflet mobility must be restored in order to prevent tethering. Thus, it is strongly recommended that the posterior leaflet is systematically widened, even in the presence of an apparently large leaflet surface.