Cerebral protection via a transcerebral gradient-guided strategy in pediatric off-pump 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.