Cerebral Protection via Transcerebral Gradient-Guided Strategy in Pediatric Bidirectional Glenn

Background Off-pump bidirectional Glenn (BDG) avoids cardiopulmonary bypass (CPB), but superior vena cava (SVC) clamping may compromise cerebral perfusion. We evaluated a goal-directed anaesthetic algorithm integrating mean arterial pressure minus SVC pressure (transcerebral gradient, TSG) with cerebral near-infrared spectroscopy (NIRS). Methods We conducted a retrospective two-centre cohort study of 698 children undergoing off-pump BDG (2016–2025). The protocol targeted TSG ≥ 30 mm Hg with continuous invasive arterial and SVC pressure monitoring. Bilateral frontal NIRS was monitored continuously; clinically important desaturation was defined as a ≥ 20% fall from baseline. Stepwise interventions for TSG < 30 mm Hg and/or NIRS desaturation included vasoactive titration, ventilatory optimisation, maintenance of azygos venous drainage during anastomosis, haematocrit optimisation, and temporary autologous venous blood withdrawal with reinfusion after anastomosis. Results There were no deaths (0%, 95% CI 0–0.53%), and all patients were extubated in the operating room. TSG < 30 mm Hg occurred in 89/698 patients (12.8%, 95% CI 10.4–15.5). Cerebral NIRS desaturation occurred in 54/698 (7.7%, 95% CI 5.9–10.0); 9/54 had concomitant TSG < 30 mm Hg. Transient partial seizures occurred in 6/698 (0.86%) within the first 24 h postoperatively, all resolving without sequelae. Mean postoperative pulmonary artery pressure was 11.1 (2.3) mm Hg. Conclusions In this large off-pump BDG cohort, a standardised TSG- and NIRS-guided algorithm was feasible and was associated with low rates of cerebral desaturation and early neurological events. Prospective studies with standardised neurodevelopmental follow-up are warranted.