Anatomy of the retro-oesophageal major aortopulmonary collateral arteries in patients with pulmonary atresia with ventricular septal defect: results from preoperative CTA

To assess the frequency and anatomy of retro-oesophageal aortopulmonary collateral arteries (REMs) in patients with pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA-VSD-MAPCAs). A total of 130 consecutive PA-VSD-MAPCA patients with preoperative CT angiography (CTA) data who underwent cardiac surgery were included. A detailed analysis of MAPCA anatomy was performed using CTA. A REM was identified in 82/130 included patients (63 %). A total of 277 MAPCAs were observed in these 82 patients and were divided into groups based on REM status: REM (n=94) and non-REM (n=183). Compared with non-REMs, REMs originated at a lower level and tended to originate from the lateral side of the aorta (all p < 0.01). REMs had a higher probability of suffering stenosis (chi(2)=9.79, p < 0.01), particularly midsegment stenosis (chi(2)=6.27, p=0.01). REMs were more posterior to the bronchus at the pulmonary hilum than non-REMs (91 % vs. 51 %) (chi(2)=50.81, p < 0.01). REMs are associated with a lower level, more lateral origin, stenosis and more posterior location with respect to the bronchus at the pulmonary hilum. The unique CTA data obtained in this study showing the anatomy of REMs will be highly useful for surgeons in identifying REMs. Unifocalization is a very important surgical approach for PA-VSD-MAPCA patients. The anatomical variability of REMs becomes clinically relevant in unifocalization. CTA provides a non-invasive way to observe the anatomy of REMs. REMs are associated with lower level, more lateral origin, more midsegment stenosis. REMs tend to be posterior to the bronchus at the pulmonary hilum.