Extended aortic root replacement for treatment of left ventricular outflow tract obstruction.

Recurrent tunnel stenosis of the left ventricular outflow tract following operation for subaortic stenosis and hypoplastic aortic annulus remain a challenge for pediatric cardiac surgeons. We have recently applied a new technique of extended aortic root replacement using an aortic allograft to treat three patients who had previously been operated upon for subaortic stenosis and three who had aortic stenosis with a hypoplastic aortic annulus. This new procedure combines the concept of aortoventriculoplasty with allograft aortic root replacement and coronary artery reimplantation. The valved aortic homograft is used in place of an aortic valve prosthesis and the attached anterior mitral leaflet augments the interventricular septum to relieve the subvalvular left ventricular outflow tract obstruction. The coronary ostia are then reimplanted into the allograft and distal graft to ascending aorta anastomosis completed. Allograft aortic tissue is then used to patch the right ventricular outflow tract. There have been no operative or late deaths. One patient developed Serratia marcescens mediastinitis but recovered uneventfully after mediastinal drainage. Two cases of transient complete heart block reversed spontaneously. A patient with type II hyperlipidemia developed postpericardiotomy syndrome early, which resolved but then required reoperation at six months for stenosis of the distal anastomosis and left main coronary stenosis, both thought to be complications of his underlying disease. Completely benign convalescence and early follow-up has occurred in the last two patients. This modified technique using aortic allograft was very helpful in treating these difficult problems, and the lack of mortality, limited morbidity, and good function results are encouraging.