Transmitral Septal Myectomy and Complex Mitral Valve Repair for HOCM Through Periareolar Minimally Invasive Access

Procedure

Through a partial superior periareolar skin incision, a small right anterolateral thoracotomy was performed at the 4th intercostal space and a 5 mm 0° thoracoscope was introduced through the same intercostal space 7 cm laterally. A 2 cm skin incision was used to gain access to the femoral artery and vein and then the Seldinger technique was used for cannulation of the vessels for cardiopulmonary bypass. Once extracorporeal circulation was established, the ascending aorta was clamped with a Cygnet clamp (Vitalitec, Balgheim, DE) and the heart stopped with infusion or cold crystalloid cardioplegia (Custodiol) in the aortic root. The left atrium was opened and retracted using a standard MICS atrial retractor; a Crown FlexTM atrial retractor was also installed (Geister, Tuttlingen, DE) to improve the visualization of the mitral valve. The midline of the anterior mitral annulus and the trigons were signed with a skin marker, the insertion of the anterior leaflet was cut between the commissures, and the leaflet fixed to the posterior annulus with a 4/0 prolene. Transmitral myectomy of the interventricular septum was performed and extended distally to the origin of the papillary muscles. The anterior head of the accessory bifid papillary muscle was identified and isolated with the help of a surgical hook and then cut 2-3 mm distally from the base of insertion on the body of the muscle. The chordae that branched out from the head was cut at the distal end on the insertion on the anterior leaflet of the valve. A bovine eterologous pericardial patch was cut in a costume-made size on the basis of the measure of the intertrigone distance that the cardiologist had previously taken performing the TEE. The patch was then sutured using a 4/0 prolene running suture to the anterior annulus from the center to one and then the other trigone to avoid distortion. Another running suture with a 4/0 prolene was perfomed from the opposite site of the patch to the detached portion of the anterior leaflet. This procedure was made to extend the surface of the anterior leaflet and move backward the coaptation of the mitral valve, thus the risk of systolic anterior motion is averted. Two 4/0 GoreTex (W.L. Gore and Assoc, Inc, Flagstaff, AZ, USA) neochords were implanted on the anterolateral and posteromedial papillary muscles and lead to the free margin of the anterior leaflet. The length of the neochords was assessed by a fine-tuning hydrostatic test, filling the left ventricle with saline solution.