Risk Factor Analysis And Diagnosis Of Portal Vein Stenosis/Occlusion After Pediatric Liver Transplantation

Purpose:To explore the risk factors for portal vein stenosis/occlusion（PVS/O）after liver transplantation in children and to summarize its treatment experience to inform clinical management.Methods:A retrospective analysis was performed on the pediatric liver transplants performed in our hospital from June 2006 to June 2019,to divide them into PVS/O and non-PVS/O groups according to the occurrence of PVS/O after the first balloon dilation,to compare the case data of the two groups,and to analyze the risk factors associated with the possible occurrence of PVS/O after the operation.Results:From June 2006 to June 2019,113 cases of pediatric liver transplantation were performed in our hospital,among which 31 cases were not included in this study due to death or incomplete case information,82valid cases,16 cases in PVS/O group and 66 cases in non-PVS/O group.The results of the analysis showed that Kasai surgical history（PVS/O group:8/16,non-PVS/O group:14/66,P=0.020）,recipient portal vein trunk diameter（PVS/O group:4.0±0.9mm,non-PVS/O group:5.8±1.5mm,P=0.000）,donor and recipient portal vein diameter difference（PVS/O group:4.7±2.4mm,non-PVS/O group:3.2±2.0mm,P=0.031）were statistically significant between the two groups,while age,gender,weight,donor portal vein diameter,PELD score,liver-free period,graft recipient body weight ratio（GRWR）,surgical time,postoperative complication of the biliary tract,postoperative infection,abdominal drainage tube retention time,intensive care unit（ICU）stay,postoperative ventilator use time,total hospital days were not statistically significant.In 16 cases of PVS/O,the first treatment was percutaneous balloon dilation,3 cases of PVO failed,and 13 cases of PVS achieved satisfactory results.6 cases of the 13 patients experienced restenosis after the first balloon dilation treatment,and the restenosis rate was 46.2%,among which2 patients underwent stenting,and the stent patency was good during follow-up.Comparing the clinical data of the restenosis group and the non-restenosis group,the difference in donor-recipient portal vein diameter（6.7±1.3mm in the restenosis group,4.3±2.6mm in the non-restenosis group,P=0.001）,stenosis pressure（32.2±3.9cmH₂O in the restenosis group,22.4±5.1cmH₂O in the non-restenosis group,P=0.003）,stenosis pressure（23.3±4.4cmH₂O in the restenosis group,15.6±3.7cmH₂O in the non-restenosis group,P=0.006）,stenosis diameter（1.7±0.6mm in the restenosis group,2.6±0.3mm in the non-restenosis group,P=0.006）was statistically significant between the two groups.Conclusions:1.Poor recipient portal vein development,donor portal vein mismatch,and history of Kasai surgery are risk factors for PVS/O after transplantation;2.Percutaneous balloon dilation is safe and effective in treating PVS after liver transplantation in children,but the incidence of re-stenosis is high,and stenting is required in cases where repeated dilation is ineffective;the incidence of re-stenosis correlates with the initial severity of PVS,and large differences in donor portal vein diameter at the time of transplantation and high pressure in the stenotic segment before and after balloon dilation therapy may be predictors of re-stenosis.