Introduction: Portal perfusion is a critical element of graft function and complication prevention in pediatric liver transplant recipients. Various factors affect portal blood flow, highlighting the importance of adequate venous outflow and the quality of portal reconstruction. This underscores the significance of portal inflow modulation (PIM) in pediatric liver transplantation, necessitating ongoing research in this field.
Patients and Methods: This prospective study was conducted in a single center, focusing on pediatric patients who underwent left lateral section (LLS) liver transplants from June 2023 to February 2024. A total of 27 patients were operated at the V. I. Shumakov Transplantology & Artificial Organs National Medical Research Center. Transit time flow measurement (TTFM) and Doppler ultrasonography (DUS) were utilized to measure volumetric portal and arterial flow intraoperatively and post-operation. The PIM threshold was set at a portal flow/100 g of graft weight exceeding 210 mL/100 g/min. Splenic artery ligation (SAL) or splenectomy (SE) were performed for PIM.
Results: The median age of the patients was ten months (range: 7.5 - 22.8 months), with biliary atresia being the predominant indication for transplantation (70.4%). Biliary hypoplasia accounted for 11.1%, followed by less frequent indications. Most patients (96.3%) received a living donor liver transplant. The median graft weight and graft-to-recipient weight ratio (GRWR) were 280 grams and 3.5%, respectively. The median portal flow (PF) per 100 g of graft weight was 192 ml/min/100g.
PIM was required in 10 cases, with SAL performed in 7 and SE in 3 cases. The mean PF at reperfusion was 217 ml/min/100g, significantly decreasing to 200.3 ml/min/100g post-PIM (p < 0.05). Furthermore, patients with PF > 210 ml/min/100g demonstrated significantly lower graft arterial flow at reperfusion (p < 0.05). The average velocity of portal flow, according to DUS, dramatically decreased from 57.4 cm/sec to 31 cm/sec by the end of the second postoperative week. Two patients experienced complications greater than Clavien III.
Conclusion: Portal inflow modulation may be required in selective pediatric patients after partial liver transplantation. Intraoperative measurement of volumetric portal and arterial flow, alongside Doppler ultrasonography, proved to be informative methods. Further research is essential to optimize outcomes in pediatric liver transplant recipients.