Robotic Endoscopic Excision Accessory Mitral Leaflet

Wednesday, October 21, 2009 - Accessory mitral valve is an uncommon cause of left ventricular outflow tract obstruction in the adult patient. 1 Excisional therapy has traditionally been performed through the proximal aorta by using a median sternotomy. We report the excision of an obstructive accessory mitral leaflet through the left atrium using a right chest endoscopic approach with the da Vinci Robotic System (Intuitive Surgical, Sunnyvale, Calif).

Clinical Summary:

A 43-year-old man presented with dyspnea on exertion of 1 years’ duration. Examination revealed a body mass index of 36.7 kg/m2 and a systolic cardiac murmur. Transesophageal echocardiography demonstrated a membranous structure in the left ventricular outflow
tract with a parachute action during systole. Chordal attachment suggested this membranous structure was an accessory mitral leaflet. Peak systolic gradient across the membrane measured 45mm Hg. Right and left cardiac catheterization confirmed the echocardiographic
findings and showed normal coronary arteries. Surgical excision was undertaken to relieve symptoms.

At the time of the operation, the heart was approached endoscopically through 4 ports in the third, fourth, and sixth intercostal spaces of the right lateral chest (Figure 1). Intermittent insufflation with carbon dioxide was used to create working space for pericardiotomy and traction sutures. Cardiopulmonary bypass, endoaortic balloon occlusion, and antegrade cardioplegia were achieved through the femoral vessels, and pulmonary artery venting and retrograde cardioplegia administration were achieved through the right internal jugular vein by using the Port Access System (Cardiovations, Somerville, NJ). The left atrium was entered immediately anterior to the right pulmonary veins, and the atrial septum was retracted anteriorly to expose the mitral valve. The anterior mitral leaflet was partially detached to visualize the left ventricular outflow tract. An accessory mitral leaflet with chordal tissue attachment was then excised with the robotic instruments, assisted by a handheld shafted forceps inserted through the service port (Figure 2). The anterior mitral leaflet was patched with glutaraldehyde-treated autologous pericardium to prevent leaflet shortening with repair. A vent through the closed left atriotomy and across the mitral valve was used to ensure air removal. Aortic occlusion time was 77 minutes. Postoperative echocardiography demonstrated a peak systolic left ventricular gradient of less than 7 mm Hg and normal mitral valve function. The patient was discharged on postoperative day 3 after an uncomplicated recovery and is in New York Heart Association class 1 at 6 weeks after the operation.