Endovascular management of acute portal vein thrombosis in pediatric liver transplant recipients less than 20 kg.

Background: Pediatric recipients of orthotopic liver transplants are at risk for post-transplant complications, particularly acute portal vein thrombosis, which jeopardizes patient survival and graft function. The incidence and impact of portal vein thrombosis are more severe in children compared to adults, with those under 5 most vulnerable to thrombotic events.

Objective: This study aims to report our institutional experience with endovascular interventions for treating portal vein thrombosis in 11 pediatric liver transplant recipients who presented within 30-days post-transplant.

Materials and methods: An IRB-approved retrospective review was conducted on pediatric patients (< 18 years of age) from a single tertiary care institution who received an orthotopic liver transplant and were diagnosed with acute (< 30 days) portal vein thrombosis, from July 2019 to April 2022. Patient demographics, procedural characteristics, and outcomes were recorded.

Results: Eleven patients were treated with percutaneous recanalization at a median of 6-days post-transplant for portal vein thrombosis. Median age at the time of transplant was 1.1 years (range 0.64 to 2.14), weight of 8.7 kg (range 6.1 to 18.9 kg), and body mass index of 18.2 (range 14.5 to 21.9). Portal venous access was obtained via trans-hepatic (n = 6) or trans-splenic (n = 4), or both (n = 1) under ultrasound guidance. Mechanical thrombectomy (n = 3), balloon angioplasty (n = 11), and pulse-spray tPA (n = 3) were performed to restore flow to the portal system. Technical success was achieved in all cases (n = 11). The median reduction in portal venous pressure gradient was 10 mmHg (range 4 to 15). One-year primary patency was 70% (7/10), primary-assisted was 100% (1/1), and secondary patency was 100% (3/3). There were no immediate procedure-related complications.

Conclusion: Acute post-transplant portal vein thrombosis is a significant complication following pediatric liver transplantation with high morbidity. In the early post-transplant period, endovascular interventions to restore portal flow are safe and can produce durable results.