Introduction:  Vascular complications are more common in pediatric liver transplantation (PLT). We present our pilot experience with flow measurement (FM) in pediatric recipients and compare the results with standard outcomes in adults.
Methods: We analyzed MF data from PLT performed between 2023 and 2025. We compared them with those described in the literature, looking for associations with intraoperative ultrasound (US), recipient and transplant data, and vascular events. We used as endpoints maximum portal velocity (Vmax), peak systolic velocity (PSV), and arterial resistance index (RI), pre- and post-anastomosis portal flow, as well as post-anastomosis arterial flow (ml/min). Measuring probes ranging from 2 to 8 mm were used depending on vessel size.
Results: Flow and US were measured in 44 patients. Biliary atresia was the main indication in 44%. The median age and weight at transplant were 66.6 months (range 1.4–171) and 20 kg (4.4–62), respectively; the mean graft weight was 480 g (mean GWGR 3.4%). There were 5 whole grafts, 31 reduced grafts (11 atypical reduction, 14 split, 6 living donor). Significant collateral circulation was reported in 77% of cases, and 11% required an arterial or venous graft.
Mean pre and post-anastomosis portal and arterial flow were lower than the adult standard (54.3/88.5 ml/min/100g vs 100-250 ml/min/100g) and (50 vs 100 ml/min) respectively. Intraoperative mean US values, Vmax, PSV, and RI, were 52.2 and 63.5 cm/sec and 0.6, respectively, with no significant  correlation with MF values.
The absence of flow detected in both tests led to the arterial anastomosis being redone in 2 patients. In 9 cases with portal hyperflow or decreased arterial flow and/or  splenomegaly, the splenic artery was ligated after elevated portal pressure was confirmed.
Three arterial complications and 1 portal stenosis were reported during the postoperative period, all resolved by surgery/interventional radiology. No  differences were found based on graft type or size.
Conclusion: FM in PLT proved to be a useful and simple tool that complements US data and is capable of preventing thrombotic complications through graft flow modulation maneuvers or re-anastomoses. Acceptable values ​​are lower than those described for adults, and multicenter studies are needed to validate them.