Long-Term Outcome of Portal Vein Stent Placement in Pediatric Liver Transplant Recipients: A Comparison with Balloon Angioplasty
Portal vein stenosis remains a significant cause of graft failure and postoperative morbidity in liver transplant recipients. In the case of pediatric liver transplants it is particularly important because these patients have much longer life expectancies and there are frequent size discrepancies between the donors and recipients. In this study the investigators retrospectively analyzed the cases of 50 patients with a median age of 14 months who underwent percutaneous transhepatic balloon angioplasty (n=12), transhepatic stent placement (n=18), or intraoperative transmesenteric (n=20) stent placement. For the evaluation of patency of angioplasty vs. stent placement, primary patency was defined as the lack of portal vein restenosis detected via ultrasound and/or CT. The authors also looked at procedural complications, functional stent stenosis, and stent fractures. Within these groups the 1-, 5-, and 10-year primary patency rates were 75% (angioplasty), 100% (transhepatic stent), and 85-90% (transmesenteric stent). Clinical success was seen in 8 out of 9 cases of angioplasty only, 16 out of 16 cases of transhepatic stent, and 20 out of 20 cases of transmesenteric stent placement. There were 3 recurrences seen with angioplasty only and with transmesenteric stent placement. There was only one major complication seen with transhepatic stent placement which was a portal vein tear during post-stent angioplasty. There were three major complications seen with transmesenteric stent placement which manifested as acute stent thrombosis. No major complications were seen with angioplasty only. The researchers ultimately concluded that there was no statistically significant difference between the three groups in terms of the long term primary patency rates and that angioplasty should be considered as the first line treatment for portal vein stenosis in pediatric liver transplant recipients.
Figure 4. An 11-month-old boy who underwent lateral-segment living donor liver transplantation and transmesenteric stent placement. (a) Venogram via the inferior mesenteric vein after end-to-end portal vein anastomosis shows near total occlusion of the main portal vein (arrow). (b) A self-expandable stent (8-mm diameter) was placed in the main portal vein, followed by balloon angioplasty (6-mm diameter). (c) Post-procedural fluoroscopy shows a remaining waist deformity (arrows) in the stent. (d) Coronal reconstructed computed tomography obtained 2 weeks after stent placement shows fully expanded stent with portal vein flow maintenance. (e) Doppler ultrasonography obtained 114 months after liver transplantation shows brisk portal vein flow.
This paper emphasizes the importance of starting conservatively in treating portal vein stenosis following pediatric liver transplant. It also emphasizes the fact that regardless of method, these patients still require very close follow up and often require repeated angioplasty for re-stenosis early in life. While stenting in these patients is often inevitable, it does not come without risks and can even limit the ability to undergo future repeat liver transplant if needed. As with all things IR, every case poses unique challenges and there will likely be instances when using a stent as the first line treatment may be necessary. This article opens the door for future research, as there is currently no consensus on specific indications and timing of stent placement.
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Shim D, Ko G, Sung K, Gwon D, Ko H. Long-Term Outcome of Portal Vein Stent Placement in Pediatric Liver Transplant Recipients: A Comparison with Balloon Angioplasty. J Vasc Interv Radiol. 2018; 29: 800-808.
Caleb L. Mills, MD PGY-4
Department of Radiology
Wake Forest Baptist Medical Center