A Ring-Reinforced Right Ventricle to Pulmonary Artery Conduit Is Associated with Better Regional Mechanics after Stage I Norwood Operation

Background:The right ventricle to pulmonary artery conduit(RVPAC)may impair right ventricular(RV)function in patients with functional single right ventricles.Modification of the RVPAC using a ring-reinforced end with dunked insertion into the RV through a limited ventriculotomy may reduce the impact on RV function.We compared RV segmental strain between patients with a traditional RVPAC and ring-reinforced RVPAC using feature tracking cardiovascular magnetic resonance(CMR)imaging.Methods:Patients with CMR examinations after Stage I operation with RVPAC between 2000 and 2018 were reviewed.Ventricular mass,volumes,late gadolinium enhancement(LGE),and peak radial and circumferential strain of the 4 segments near the RVPAC insertion site were analyzed.Results:The study included 71 CMR examinations in 61 patients(30 traditional RVPAC,31 ring-reinforced RVPAC).Prior to Stage II,the ring-reinforced RVPAC group had better peak radial strain and circumferential strain in 1 of 4 segments proximal to the RVPAC insertion site compared to the traditional RVPAC group.Prior to Stage III operation,the ring-reinforced group had better peak radial and circumferential strain in 2 of 4 segments.LGE at the RVPAC insertion site was observed in 97%of patients before Stage II and 95%of patients before Stage III.RVPAC type and regional strain were not associated with transplant-free survival during a median follow-up of 6.3 years.Conclusions:Compared to a traditional RVPAC,the ring-reinforced RVPAC is associated with improved regional mechanics at the conduit insertion site.Further investigation of long-term outcomes after ring-reinforced RVPAC is warranted.