Right Ventricle to Pulmonary Artery Conduit Size Is Associated with Conduit and Pulmonary Artery Reinterventions After Truncus Arteriosus Repair

We studied conduit-related risk factors for mortality, conduit reintervention, conduit replacement, and pulmonary artery (PA) reinterventions after truncus repair. Patients who underwent truncus repair at our institution between 1995 and 2019 were studied. Cox proportional hazards modeling evaluated variables for association with mortality, time to conduit reintervention, time to conduit replacement, and time to PA reintervention. Truncus was repaired in 107 patients at median age of 17 days (IQR 9-45). Median follow-up time was 7 years. Aortic homografts were implanted in 57 (53%) patients, pulmonary homograft in 40 (37%), and bovine jugular conduit in 10 (9%). Median conduit size was 11 mm (IQR 10-12) and median conduit Z-score was 1.71 (IQR 1.08-2.34). At 5 years, there was 87% survival, 21% freedom from conduit reinterventions, 37% freedom from conduit replacements, and 55% freedom from PA reinterventions. Conduit size (HR 0.7, 95%CI 0.4-1.4, p=.41) and type (aortic homograft reference; bovine jugular vein graft HR 0.6, 95% CI 0.08-5.2, p=.69; pulmonary homograft HR 0.7, 95% CI 0.2-2.3, p=.58) were not associated with mortality. On multivariate analysis, the hazard for conduit reintervention, conduit replacement, and PA reintervention decreased with increasing conduit Z-score values of 1 to 2.5 (non-linear relationship, p.01), with little additional reduction in hazard beyond this range. Implantation of a larger conduit within Z-score values of 1 and 2.5 is associated with a decreased hazard for conduit reintervention, conduit replacement, and PA reintervention after truncus repair. The type and size of the conduits did not impact mortality.