[Ascending Aorta Replacement and Extended Myectomy for Acute Aortic Dissection and Coexistent Hypertrophic Obstructive Cardiomyopathy;Report of a Case].

Emergent ascending aortic replacement and extended myectomy were performed in a woman with acute aortic dissection who was aged 63 years. Preoperative transthoracic echocardiography performed in the intensive care unit showed only slight left ventricular outflow tract (LVOT) obstruction, but intraoperative transesophageal echocardiography after induction of anesthesia revealed pericardial effusion, systolic anterior motion(SAM), and associated mitral regurgitation(MR). Perioperative SAM and MR are sometimes facilitated under various hemodynamic conditions, but in this case, the left ventricular wall was thick and LVOT appeared to be obstructive by a hypertrophied septum. Structural hypertrophic obstructive cardiomyopathy (HOCM) was diagnosed, and septal myectomy and aortic replacement were performed. After ascending aortic replacement and simultaneous extended myectomy with resection of abnormal band, weaning from cardiopulmonary bypass was smooth without SAM and MR. The patient was discharged from hospital 24 days postoperatively with no major complications. Extended myectomy should be considered if structural HOCM is diagnosed, even when aortic replacement for the dissected aorta is the primary procedure.