Minimally Invasive Septal Myectomy for the Treatment of Hypertrophic Obstructive Cardiomyopathy and Intrinsic Mitral Valve Disease

Abstract

Objective

Transaortic left ventricular septal myectomy described by Morrow is a classical procedure for the treatment of systolic anterior motion of the mitral apparatus associated with hypertrophic obstructive cardiomyopathy (HOCM). We aimed to review our results of transmitral septal myectomy and mitral valve repair/replacement in patients with intrinsic mitral valve disease associated with HOCM, operated on through a minimally invasive approach.

Methods

Between 2005 and 2014, 19 patients [7 men (37%); mean (SD) age, 69.4 (14.5) years] were treated with minimally invasive approach for degenerative mitral regurgitation and HOCM. Preoperative peak left ventricular outflow tract (LVOT) gradient was 66 (24) mm Hg. Severe mitral regurgitation was diagnosed in 16 cases (84%). New York Heart Association functional class III to IV heart failure was present in 13 patients (68%).

Results

Fifteen patients (79%) underwent mitral valve replacement, and four patients (21%) underwent mitral valve repair. Left ventricular outflow tract obstruction was corrected directly in all patients via the mitral valve with septal myectomy/myotomy, avoiding aortotomy in majority of the patients. No significant prolongation of extracorporeal circulation/aortic cross-clamping times was observed (P = 0.41 and P = 0.67, respectively) when compared with a similar population without HOCM. No iatrogenic ventricular septal defect developed in treated patients. No hospital mortality occurred. Resting LVOT gradient reduced at discharge to 13 (22) mm Hg (P = 0.025).

Conclusions

Transmitral left ventricular septal myectomy in patients with degenerative mitral valve disease is quite a simple, feasible, and effective technique and does not require aortotomy in most cases. It can be performed with low early mortality and satisfactory resolution of LVOT obstruction in a minimally invasive setting.