Extended aortic root replacement with aortic allografts.

Complex left ventricular outflow tract obstruction after operation for subaortic stenosis or with hypoplastic aortic anulus remains a challenge for pediatric cardiac surgeons. We have recently applied a new technique of extended aortic root replacement using a cryopreserved aortic allograft to treat two patients who had previously been operated on for subaortic stenosis and a third who had aortic stenosis with a hypoplastic aortic anulus. This new procedure combines the concept of aortoventriculoplasty with 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 an anastomosis between the distal graft and the ascending aorta is completed. Allograft aortic tissue is then used to patch the right ventricular outflow tract. One patient had aortic stenosis with annular hypoplasia and did well after extended root replacement. Two patients had previous operations for subaortic stenosis before undergoing extended aortic root replacement. One required mediastinal exploration and drainage at 2 weeks for Serratia marcescens mediastinitis and bacteremia, but uncomplicated recovery followed. The other patient had complete heart block for 2 days, but normal sinus rhythm resumed and convalescence was benign. This modified technique with the aortic allograft was very helpful in treating these difficult problems, and the lack of mortality, limited morbidity, and good functional results are encouraging.