[I-S06-05] 閉塞性肥大型心筋症に対する積極的外科治療の成績
キーワード：Hypertrophic cardiomyopathy, Myectomy, Surgery
The ordinary surgical procedures for relief of HoCM is performing simple excision of muscle under direct vision. Recently our procedure has changed from the classic Morrow procedure to a more extended septal myectomy. We start the incision in the septum slightly to the right of the nadir of the right aortic sinus and continue leftward toward the mitral valve. We have also treated two other groups of patients with HCM, those with mid ventricular obstruction and those with apical hypertrophic cardiomyopathy. We have performed mid ventricular myectomy through an apical incision in a few patients with satisfactory relief of gradients and improvement in symptoms. There has been no hospital mortality and no late complications related to ventricular incision.During the past 5 years, 42 patients (83％ female) have had septal myectomy for obstructive hypertrophic cardiomyopathy (HCM) at our institute. No early mortality for extended myectomy, and all patients survive for 18±16 months. Follow-up studies of patients having septal myectomy suggest that operation reduces risk of ventricular arrhythmias and may reduce risk of sudden cardiac death.For patients with small left ventricular cavity size, apical myectomy make the left ventricle enlarge, and can improve diastolic function. The goal of this procedure is not only to fix the SAM, but also to augment left ventricular end-diastolic volume. Postoperative hemodynamic studies have documented improvement both in left ventricular end-diastolic volume and left ventricular stroke volume.