Comparing right ventricle to pulmonary artery conduit with modified Blalock-Taussig shunt in hypoplastic left heart syndrome undergoing Norwood procedure: A meta-analysis

The Norwood procedure is the first palliative surgery for Hypoplastic Left Heart Syndrome (HLHS). Traditionally, pulmonary circulation was supplied via a modified Blalock-Taussig (mBT) shunt, but the right ventricle-to-pulmonary artery (RV-PA) conduit has recently been introduced. A systematic review and meta-analysis identified 13 studies with 905 patients comparing RV-PA and mBT outcomes. RV-PA was associated with significantly lower short-term mortality (RR: 0.62 [0.45–0.85], p = 0.003) and interstage mortality (RR: 0.18 [0.05–0.63], p = 0.008). Before the hemi-Fontan procedure, RV-PA showed better late hemodynamic outcomes, including a lower pulmonary-to-systemic (Qp/Qs) ratio (MD: 0.25 [-0.43 to −0.07], p = 0.007), higher aortic diastolic pressure (MD: 5.22 [2.56–7.87], p < 0.001), and higher Nakata index (MD: 30.54 [3.34–57.75], p = 0.03). RV-PA had no significant impact on right ventricular compliance, as indicated by similar RV end-diastolic pressure (RVEDP; MD: 0.44 [-0.52 to 1.40], p = 0.37). Although RV-PA had a higher but non-significant incidence of shunt stenosis (RR: 4.68 [0.21–105.18], p = 0.33), its advantages outweighed this limitation. Kaplan–Meier analysis showed superior 3-year survival for RV-PA (72% vs. 61% for mBT, p = 0.005). These findings support RV-PA as the preferred shunt for improving survival, hemodynamic outcomes, and perioperative success in HLHS patients undergoing the Norwood procedure.