Impact of Residual Lesions following Norwood Palliation

Residual lesions may be important in both in-hospital and post-discharge outcomes following congenital heart surgery. We sought to understand their impact (measured by residual lesion score, RLS) on Norwood outcomes.

We reviewed outcomes post-Norwood procedure (2015-2017) in the Pediatric Heart Network's RLS study, including transplant-free survival, reinterventions, and days alive and out of hospital 12-months post-Norwood among survivors to Norwood discharge. Residual lesions were assessed by echocardiography and clinical characteristics at discharge. Global rank scores of outcomes of interest weighted on severity, and win/loss ratios were calculated. RLS defined Class-1 (no residua), Class-2 (minor residua), Class-3 (major residua).

Among 249 neonates, 239 could be assigned an RLS Class. Of 206 survivors to hospital discharge, RLS was not associated with post-discharge re-interventions. At 12 months, 53 (22%) died, including 3/4 after transplant. Of 192 with follow-up to assess days alive and out of hospital through 12 months, RLS Class-3 had 49 fewer days. Transplant-free survival 12 months post-Norwood was lower for Class-3 vs. Class-1 (HR:3.08, 95% CI: 1.51, 6.28, P=0.002). Global rank score identified a higher ratio of wins for RLS Classes 1&2 vs. Class-3.

Major residual lesions post-Norwood are associated with poorer transplant-free survival and fewer days alive and out of hospital at 12 months but are not associated with increased rates of reintervention post-Norwood discharge. Global rank scores confirmed poorer outcomes in Class-3. Given these findings, patients with RLS Class-3 warrant close follow-up.