Structural imaging features associated with non-occlusive hepatic artery hypoperfusion in pediatric liver transplantation.

PURPOSE: To investigate structural imaging features of non-occlusive hepatic artery hypoperfusion syndrome (NHAHS) in pediatric liver transplant recipients. METHODS: This retrospective single-center study included 78 pediatric liver transplant recipients, divided into NHAHS (n = 17) and non-NHAHS (n = 61) groups. Preoperative and postoperative multidetector CT was used to assess arterial and portal venous parameters, splenic size, and vascular ratios. Doppler ultrasonography was used to evaluate portal venous flow velocity. NHAHS diagnosis was confirmed by digital subtraction angiography. Interobserver agreement was assessed using intraclass correlation coefficients. ROC curve analysis was performed to evaluate the discriminatory performance of imaging parameters for identifying NHAHS. RESULTS: Patients with NHAHS had significantly larger preoperative splenic artery diameter and splenic volume (p = 0.044 and p = 0.024, respectively). Although portal venous diameters did not differ significantly between groups, the distribution of portal vein thrombosis subtypes and portosystemic shunt types differed significantly, with chronic thrombosis and splenoportosystemic shunts more frequent in the NHAHS group (p = 0.020 and p < 0.001, respectively). Postoperatively, recipient hepatic artery diameter and portal vein flow velocity were significantly higher in patients with NHAHS (p = 0.010 and p = 0.021, respectively). On preoperative donor CT, the donor hepatic artery and donor portal vein diameters were significantly smaller in the NHAHS group (p = 0.024 and p < 0.001, respectively). ROC analysis showed that postoperative recipient hepatic artery diameter had moderate discriminatory performance for identifying NHAHS (AUC = 0.716; 95% CI 0.555-0.878, p = 0.007), yielding a sensitivity of 64.70% and specificity of 83.60% at a cutoff of > 3.5 mm. In multivariable analysis, preoperative splenic volume remained independently associated with NHAHS (OR = 1.157 per 100 mL increase, 95% CI 1.004-1.333, p = 0.044), whereas postoperative recipient hepatic artery diameter did not (p = 0.234). CONCLUSION: NHAHS in pediatric liver transplant recipients appears to reflect complex portal-hepatic hemodynamic interactions rather than isolated anatomical abnormalities. In multivariable analysis, preoperative splenic volume was the only parameter independently associated with NHAHS, whereas postoperative recipient hepatic artery diameter was significant only in univariable comparison. These imaging features may support closer postoperative surveillance in selected patients but should be considered supportive rather than definitive markers; given the limited number of events, these exploratory findings require validation in larger multicenter cohorts.