INTERRUPTED AORTIC-ARCH - IMPACT OF SUBAORTIC STENOSIS ON MANAGEMENT AND OUTCOME

Interrupted aortic arch (IAA) is often related developmentally to suba ortic obstruction (SAG). When severe, SAO must be addressed in surgica l management of IAA. From 1990 to 1993, 25 neonates presented for init ial surgical management of IAA complexes. Associated lesions were vent ricular septal defect (VSD) with or without atrial septal defect (19 p atients), truncus arteriosus (3 patients), tricuspid atresia with tran sposition of the great arteries (1 patient), aortic atresia with VSD ( 1 patient), and d-transposition of the great arteries with VSD (1 pati ent). Overall hospital mortality was 20% (five deaths). One death was related to sepsis and two to sudden hemodynamic decompensation (a 2-kg premature infant after arch repair and VSD closure and a neonate with IAA-truncus arteriosus after arch repair and truncus repair with aort ic root replacement). Two deaths were related to low cardiac output in patients with severe subaortic narrowing (<3 mm by two-dimensional ec hocardiography), which was not addressed surgically. Of 10 additional patients judged preoperatively to have severe SAG, 1 underwent resecti on of the infundibular septum together with VSD closure and arch recon struction, acid 9 underwent a modification of Norwood's operation with arch reconstruction and proximal pulmonary artery to aortic anastomos is (7 with systemic to pulmonary artery shunts and 2 with right ventri cle to pulmonary artery outflow tract reconstruction). One patient die d 2 months after surgery of staphylococcal sepsis. All 9 others were d ischarged well. Subaortic narrowing is a physiologically important ele ment of IAA complexes. When SAO is severe, satisfactory initial pallia tion can be achieved by a modification of Norwood's operation.