Surgical management of subaortic stenosis in patients with single ventricle and transposition of the great vessels.

Subaortic stenosis can develop in patients with single ventricle and transposition of the great vessels. Its presence increases the risk of septation or Fontan repair, and reports of surgical management have indicated high mortality. This report describes the results of an approach that includes direct resection of the stenosis via an aortotomy, and delay of the Fontan repair to a later date. Nine children with single ventricle underwent surgery for subaortic stenosis from 1968 to 1984. Three deaths occurred postoperatively from ventricular dysfunction in patients who underwent either conduit bypass (one patient) or repair via ventriculotomy (two patients). Of the six long-term survivors, one infant underwent ventriculotomy and subaortic resection, and the last five patients had subaortic resection via an aortotomy without any other simultaneous procedure. Avoidance of ventriculotomy and decreased cardiopulmonary bypass time lowers the risk of stenosis repair in the presence of a hypertrophied ventricle. Fontan repair after some regression of the ventricular hypertrophy is recommended, and has been accomplished in one patient to date. All patients repaired via aortotomy are alive and well 1 to 6 years postoperatively.