Severe Mitral Regurgitation due to Left Atrial Aneurysm Corrected by Endoatrial Patch Plasty

Congenital aneurysm of the body of the left atrium causing severe mitral incompetence is extremely rare. The cause of mitral incompetence has been attributed to a distortion of the mitral annulus by the aneurysm, or to coexisting pathology in the mitral valve apparatus. Surgical techniques to treat this condition include excision of the aneurysm along with mitral valve repair or replacement. Herein is described the case of a 30-year-old man with large aneurysm of the left atrial body and severe mitral regurgitation (MR) treated by endoatrial patch plasty. The mitral incompetence was due to prolapse of the posterior mitral annulus into the neck of the aneurysm. Under cardiopulmonary bypass, the neck of the aneurysm was closed using a Dacron patch. Endoaneurysmorrhaphy with a Dacron patch effectively restored the mitral competence and simultaneously excluded the aneurysm from the left atrium. To further strengthen the posterior mitral annulus, a mitral annuloplasty was added using a rigid Carpentier-Edwards ring. The patient was anticoagulated with warfarin for six weeks after surgery. Transthoracic echocardiography performed at a six-month follow up confirmed the absence of any residual aneurysm or MR. To the authors' knowledge, this is the first case of left atrial aneurysm with severe MR to be treated in this way.