Creation of 6-10mm Diameter Transjugular Intrahepatic Portosystemic Shunts Using a Novel TIPS Stent Graft in a Swine Model

Abstract

PurposeTo assess the delivery, function, and patency of a new expanded polytetrafluoroethylene encapsulated TIPS stent- graft ("Liverty") in an animal model. Materials and MethodsTIPS were created in 2 successive groups: 14 single & 10 overlapping devices, in swine weighing 52-64kg. Explants occurred at 30 (n=10) and 60 (n=14) days. These were evaluated by histomorphometry and histopathologic evaluations, and electron microscopy. ResultsSeven 6mm, five 7mm, and twelve 10mm diameter TIPS were created using varied human TIPS access sets without complications; both sheathed and unsheathed advancement and deployment of the devices within liver tracts. One animal was sacrificed at 35d due to encephalopathy; remainder survived to endpoints. 22/24 TIPS were patent at 30 and 60-day endpoints; Mean stenosis at 30 days was 13.3% +/- 10.1%, and for 60 days was 18.44% ± 5.04%. Two shunts were occluded by tissue overgrowth at unstented native hepatic vein end and downgrowth into TIPS. Histology and electron microscopy showed well-apposed, incorporated devices lined with smooth, uniform neointimal tissue averaging 0.48mm (single devices) and 0.74mm thick (overlapped devices) with minimal adventitial inflammation. ConclusionThe new Liverty TIPS stent graft was straightforward to deploy for TIPS creation and resulted in patent 6,7, and 10mm diameter shunts in both single and overlapping configurations. One- and 2-month histology showed desired tissue healing without in-stent stenosis.