Risk factors for portal vein stenosis in pediatric liver transplantation

Portal vein reconstruction in pediatric liver transplantation using end-to-side jump graft: A case report

Attenuated portal vein (PV) flow is challenging in pediatric liver transplantation (LT) because it is unsuitable for classic end-to-end jump graft reconstruction from a small superior mesenteric vein (SMV). We thus introduce a novel technique of an end-to-side jump graft from SMV during pediatric LT using an adult partial liver graft. We successfully performed two cases of end-to-side retropancreatic jump graft using an iliac vein graft for PV reconstruction. One patient was a 2-year-old boy with hepatoblastoma and a Yerdel grade 3 PV thrombosis who underwent split LT. Another patient was an 8-month-old girl who had biliary atresia and PV hypoplasia with stenosis on the confluence level of the SMV; she underwent retransplantation because of graft failure related to PV thrombosis. After native PV was resected at the SMV confluence level, an end-to-side reconstruction was done from the proximal SMV to an interposition iliac vein. The interposition vein graft through posterior to the pancreas was obliquely anastomosed to the graft PV. There was no PV related complication during the follow-up period. Using a jump vascular graft in an end-to-side manner to connect the small native SMV and the large graft PV is a feasible treatment option in pediatric recipients with inadequate portal flow due to thrombosis or hypoplasia of the PV.

Biological abdominal wall expansion in pediatric liver recipients after transplantation with large-for-size organs

BACKGROUND

After pediatric split liver transplantation, intra-abdominal loss of domain due to large-for-size left lateral grafts is a frequent problem for fascial closure and potentially leads to reduced liver perfusion and abdominal compartment syndrome. Therefore, delayed fascial closure with the use of temporary silastic meshes and reoperation or alternative fascial bridging procedures are necessary.

METHODS

Between March 2019 and October 2021, biologic meshes were used for abdominal wall expansion in 6 cases of pediatric split liver transplantation. These cases were analyzed retrospectively.

RESULTS

One male and 5 female children with median age of 6 months (range: 0-57 months) and weight of 6 kg (range: 3.5-22 kg) received a large-for-size left lateral graft. Graft-to-recipient weight ratio (GRWR) was 4.8% (range: 1.5%-8.5%) in median. Biologic mesh implantation for abdominal wall expansion was done in median 7 days (range: 3-11 days) after transplantation when signs of abdominal compartment syndrome with portal vein thrombosis in 3 and of the liver artery in 1 case occurred. In 2 cases, bovine acellular collagen matrix and 4 cases ovine reinforced tissue matrix was used. Median follow-up was 12.5 months (range: 4-28 months) and showed good liver perfusion by sonography and normal corporal development without signs of ventral hernia. One patient died because of fulminant graft rejection and emergency re-transplantation 11 months after the initial transplantation.

CONCLUSIONS

Biologic meshes can be used as safe method for abdominal wall expansion to achieve fascial closure in large-for-size liver transplant recipients. Usage for primary fascial closure can be considered in selected patients.

Treatments and outcomes of intra-operative portal vein thrombosis in living-donor liver transplantation due to biliary atresia

BACKGROUND

Pediatric living-donor liver transplantation (LDLT) has become one of the most effective therapies for pediatric end-stage liver diseases. We aim to investigate the risk factors for intra-operative portal vein thrombosis (PVT) and the short- and long-term outcomes in children post LDLT.

METHODS

This was a retrospective analysis from 584 cases of biliary atresia (BA) patients who had undergone LDLT from January 2014 to December 2019 at our hospital. Patients were divided into PVT and non-PVT groups according to the occurrence of PVT during LDLT.

RESULTS

The median age of recipients at transplantation was 7.22 (quartiles, 6.03, 9.50) months, the incidence of intra-operative PVT was 5.31% (31/584). The independent risk factors for intra-operative PVT were the diameter of the recipient's PV not greater than 4 mm and a higher ratio of graft-to-recipient PV diameter. The cumulative survival rates of grafts and recipients were 93.5% and 93.5% in the PVT group, and 94.9% and 95.3% in the non-PVT group, respectively, without significant difference. The recovery of graft function was similar in recipients with or without interposed graft vessel (IGV). However, the incidence of PV stenosis was higher in recipients with IGV after LDLT.

CONCLUSION

Intra-operative PVT is a common complication in pediatric LDLT, but an excellent prognosis can be achieved by appropriate and individualized surgical treatment. We noted that intra-operative PVT did not affect the survival rates of grafts and recipients, but there was a higher incidence of PV complications after LDLT.

LEVEL OF EVIDENCE

Ⅲ.

Predictors of portal vein complications after pediatric liver transplantation: A German center experience

BACKGROUND

Portal vein complications (PVCs) after pediatric liver transplantation (LT) are sometimes asymptomatic, especially in the early phase, and can threaten both the graft and patient's survival. Therefore, the purpose of this study is to analyze the risk factors for portal vein thrombosis (PVT) and portal vein stenosis (PVS) after pediatric LT.

METHODS

All pediatric patients (n = 115) who underwent primary LT at Regensburg University Hospital between January 2010 and April 2017 were included in this study. The pre-, intra-, and postoperative parameters of all patients were retrospectively reviewed and risk factors for both PVT and PVS were analyzed.

RESULTS

Of the 115 patients, living donor LT was performed on 57 (49.5%) patients, and biliary atresia was the primary diagnosis in 65 patients (56%). After pediatric LT, 9% of patients developed PVT, and 16.5% developed PVS. Patient weight ≤7 kg [odds ratio (OR) 9.35, 95% confidence interval (CI) 1.03-84.9, p = .04] and GRWR >3% (OR 15.4, 95% CI 1.98-129.5, p = .01) were the independent risk factors for the development of PVT and PVS, respectively upon multivariate analysis. The overall patient survival rates at 1, 3, and 5 years were 91%, 90%, and 89%, respectively, and there was no difference in patient survival among those with and without PVCs.

CONCLUSIONS

Pediatric patients with body weight <7 kg and/or receiving a graft with GRWR >3% may develop PVCs and so require certain surgical modifications, close follow-up, and prophylactic anticoagulant therapy following transplant.

Portal vein reconstruction with cryopreserved vascular grafts: A two-edged sword

BACKGROUND

Portal vein anastomotic complications related to size discrepancy are important causes of morbidity and mortality in pediatric liver transplantation. Interposed vascular grafts in portal vein anastomosis can solve this problem. The aim of this study is to evaluate the results of pediatric liver transplantations performed using cryopreserved interposed vascular grafts between graft portal vein and superior mesenteric vein (SMV)-splenic vein (SpV) confluence.

METHODS

Twenty-nine pediatric patients received liver transplantation using cryopreserved venous grafts in our Liver Transplant Institute between 2013 and 2020 were included in this study. Demographic, clinical, and operative characteristics and postoperative follow-up were analyzed.

RESULTS

Sixteen patients (55.2%) had portal hypoplasia and five patients (17.2%) had portal vein thrombosis. In total, six patients (20.6%) suffered portal vein thrombosis in the early postoperative period. Three patients (10.3%) experienced portal vein thrombosis in the late postoperative period. Late portal vein thrombosis rate was significantly higher in patients with early portal vein thrombosis (3/6 patients [50%] versus 0/23 patients [0%]; p = .034). Lack of portal flow was significantly higher in patients with both early (50% versus 0%; p = .002) and late portal vein thrombosis (66.7% versus 6.7%; p = .03).

CONCLUSION

Preoperative portal vein thrombosis and insufficient flow are important factors affecting success of liver transplant in children. The use of interposed vein grafts in problematic portal anastomoses can overcome portal flow problems.