Clinical Implications of Major Aortopulmonary Collateral Arteries in Patients with Right Isomerism

Background. The presence of major aortopulmonary collateral arteries ( MAPCA) in patients with right isomerism may alter the prognosis, which is still unclear. Methods. From 1994 to 2003, 138 out of 155 patients (89%) with right isomerism had pulmonary stenosis or pulmonary atresia and constituted the study population. Results. Two groups of patients were identified, one with MAPCA and the other without. The MAPCA originating from descending thoracic aorta or aortic arch was noted in 9 patients (6.5 %), with a median number of MAPCA being 3 (range, 2 to 4). Patients with MAPCA commonly had congestive heart failure (8/9, 89%) and frequent lower airway infection (6/9, 67%). In comparison with patients with MAPCA and without, the intrapericardial pulmonary artery was more frequently absent ( 2 of 9 vs 1 of 129, p < 0.001), and the pulmonary arterial size was smaller (McGoon ratio < 1.5, 8 of 9 vs 57 of 129, p = 0.009) in the MAPCA group. The mean pulmonary arterial pressure measured was often higher than the suggested limit for Fontan circulation . Major aortopulmonary collateral arteries were addressed at a median of 6 months old (2 to 19 months old) in 5 patients . Although surgical mortality was not different for first- stage palliation and Glenn shunt in both groups, total cavopulmonary connection could only be performed in one patient with MAPCA with poor results. However, the 5-year survival of patients with and without MAPCA was not statistically different (74.1% vs 55.2%, p = 0.19). Conclusions. The presence of MAPCA was uncommon but still noted in patients with right isomerism. It may cause heart failure and a less favorable pulmonary vasculature for a complete Fontan-type operation