Pathology of the Aortic Arch in Hypoplastic Left Heart Syndrome: Surgical Implications

Aortic arch reconstruction plays an important role in the success of the Norwood procedure (NP) for hypoplastic left heart syndrome (HLHS). This study investigated the cardiac specimens to determine the etiology of distal aortic arch obstruction after the NP for HLHS and to locate coarctation of the aorta in HLHS untreated by surgery. This study examined 17 cardiac specimens: 9 that had NP and 8 not treated by surgery. The findings after NP showed frequent failure to resect the coarctation segment completely and failure to extend the augmentation patch into the descending aorta. Five (62.5%) of the eight hearts not treated by surgery had significant periductal coarctation of the aorta. After NP for nine patients, three (33%) had residual coarctation of the aorta. To minimize the risk of recurrent or persistent aortic arch obstruction after NP and to improve the long- and short-term outcome, the ductal tissue and the coarctation segment encircling the aortic lumen should be resected. The distal wall incision should be extended at least 5 mm beyond the distal aspect of the ductal tissue. These steps could avoid major aortic arch obstruction, promote growth of the native aortic tissue, and avoid ventricular dysfunction.