<p>The patient was a 6-year-old boy with no symptoms and a finding of a
systolic heart murmur on the left sternal border on a routine
examination. Echocardiogram showed left ventricular outflow tract
obstruction by subaortic fibrous membrane with a peak gradient of 76 mm
Hg and mild aortic valve regurgitation with preserved left ventricular
function.<br></p><div>The authors’ operation plan consisted of
right axillary minithoracotomy with central cannulation for CPB,
institution of cold blood cardioplegia in the aortic root, and subaortic
membrane resection through the aortotomy. The operation was performed
through the right axillary minithoracotomy in the 4th intercostal space
between anterior and posterior axillary lines.</div><div><p>After transverse aortotomy, the aortic valve leaflets were retracted
exposing the subvalvular obstruction. A combination of sharp and blunt
dissection was used to enucleate the circumferential shelf off the
ventricular septum and the anterior leaflet of the mitral valve. The
hypertrophied portion of the interventricular septum was resected
together with fibrotic tissue. Inspection of the aortic valve confirmed
normal coaptation.<br></p>The patient’s postoperative
course was unremarkable and he was discharged home on postoperative day
four. The patient is currently doing well as an outpatient.</div>