Conduit Size, Branch Pulmonary Artery Size, and Reoperation in Patients With Truncus Arteriosus

BackgroundOptimal right ventricle-to-pulmonary artery (RV-PA) conduit size for patients with truncus arteriosus is controversial. We aimed to determine the relationship between branch PA size and the need for conduit reoperation following repair of truncus arteriosus.MethodsWe performed a single-center chart review of patients who underwent truncus arteriosus repair from January 2009 to December 2023. Branch PAs were measured in systole, at the narrowest point if focal stenosis was present. For branch PA diameter analyses, the smaller diameter PA was used. Univariate Cox proportional hazards regression analysis was performed to determine hazard ratios (HRs) with 95% confidence intervals (CIs) for echocardiographic measures and conduit reoperation.ResultsWe included 33 patients. Median age at surgery was 23 days (range: 3--34). Thirty-two patients received a bovine jugular vein graft, one patient received an aortic homograft. Mean RV-PA conduit Z-score was 2.7 ± 0.5 and mean preoperative conduit-to-PA ratio 2.6 ± 0.6. Postoperative diameter of at least one branch PA was decreased in 31 patients (93.9%); mean change was -19% ± 17%. Mean postoperative conduit-to-PA ratio was 3.3 ± 0.9. Conduit reoperation occurred in 19 patients (58%); median time to reoperation was 1.6 years (range: 0.4-10.4). Conduit reoperation was not associated with conduit diameter or Z-score. Conduit reoperation was significantly associated with truncus type A2 or A3 PA anatomy (HR: 3.53; 95%CI: 1.14-10.94) and conduit-to-PA ratio ≥ 4 (HR: 4.94; 95%CI: 1.63-14.97).ConclusionIn a single-center cohort of children who underwent repair of truncus arteriosus, RV-PA conduit diameter was not associated with increased conduit longevity. Rather, larger postoperative RV-PA conduit to branch PA diameter ratio was significantly associated with greater hazard for conduit reoperation.