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

Abstract

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.