ROSS-KONNO OPERATION WITH RESECTION OF ENDOCARDIAL FIBROELASTOSIS FORCRITICAL AORTIC-STENOSIS WITH BORDERLINE-SIZED LEFT-VENTRICLE IN NEONATES

Background. Critical aortic stenosis with severe concentric left ventr icular hypertrophy and endocardial fibroelastosis has a substantial mo rtality rate when the conventional therapeutic strategy, ie, open surg ical or balloon valvuloplasty, is applied. During the last decade, uni ventricular repair (Norwood operation) and heart transplantation have evolved as the only viable therapeutic options. An alternative in pati ents with borderline hypoplastic left heart syndrome consists of perfo rmance of a Ross-Konno operation with surgical enlargement of the left ventricular cavity, a procedure that has the advantage of achieving a two-ventricle repair. Methods. Two neonates and 2 young infants with critical aortic stenosis, concentric left ventricular hypertrophy, and severe endocardial fibroelastosis, with echocardiographically documen ted antegrade flow in the ascending aorta, underwent a Ross-Konno oper ation combined with extensive endocardial and myocardial resection of the left ventricular septum and free wall. The incision in the ventric ular septum was closed with a wide cuff of infundibular muscle that wa s harvested in continuity with the pulmonary autograft. Results. In al l 4 patients, the operation resulted in normal aortic valve function, marked reductions of width of the left ventricular septum (median, 6.5 mm, versus 11 mm preoperatively) and the left ventricular posterior f ree wall (median, 8.5 mm, versus 15.5 mm preoperatively), and enlargem ent of the left ventricular end-diastolic volume (median, 12.5 cm(3), versus 6.5 cm(3) preoperatively). Three patients had an uneventful rec overy, with gradual improvement of left ventricular diastolic and syst olic function during the first postoperative week; 1 neonate with asso ciated mitral regurgitation died of left ventricular failure. Conclusi ons. The Ross-Konno procedure with resection of endocardial fibroelast osis may be a valuable adjunct for achieving a two-ventricle repair in borderline hypoplastic left heart syndrome. The operation results in enlargement of the left ventricular stroke volume and improvement of l eft ventricular diastolic function; in addition, resection of endocard ial fibroelastosis relieves the mechanical impairment of myocardial. f unction and therefore may promote the potential for left ventricular g rowth. (C) 1997 by The Society of Thoracic Surgeons