Background: Critical aortic stenosis with severe concentric left ventricular hypertrophy and endocardial fibroelastosis has a substantial mortality rate when the conventional therapeutic strategy, ie, open surgical or balloon valvuloplasty, is applied. During the last decade, univentricular repair (Norwood operation) and heart transplantation have evolved as the only viable therapeutic options. An alternative in patients with borderline hypoplastic left heart syndrome consists of performance 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 documented antegrade flow in the ascending aorta, underwent a Ross-Konno operation combined with extensive endocardial and myocardial resection of the left ventricular septum and free wall. The incision in the ventricular septum was closed with a wide cuff of infundibular muscle that was harvested in continuity with the pulmonary autograft.
Results: In all 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 free wall (median, 8.5 mm, versus 15.5 mm preoperatively), and enlargement of the left ventricular end-diastolic volume (median, 12.5 cm3, versus 6.5 cm3 preoperatively). Three patients had an uneventful recovery, with gradual improvement of left ventricular diastolic and systolic function during the first postoperative week; 1 neonate with associated mitral regurgitation died of left ventricular failure.
Conclusions: The Ross-Konno procedure with resection of endocardial fibroelastosis 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 left ventricular diastolic function; in addition, resection of endocardial fibroelastosis relieves the mechanical impairment of myocardial function and therefore may promote the potential for left ventricular growth.