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

Purpose: To assess the delivery, function, and patency of a new expanded polytetrafluoroethylene–encapsulated transjugular intrahepatic portosystemic shunt (TIPS) stent graft (“Liverty”) in an animal model. Materials and Methods: TIPS were created in 2 successive groups: (a) 14 single and (b) 10 overlapping devices, in swine weighing 52–64 kg. Explants occurred at 30 (n = 10) and 60 (n = 14) days. These were evaluated by histomorphometric and histopathologic evaluations and electron microscopy. Results: Seven 6-mm-diameter, 5 7-mm-diameter, and 12 10-mm-diameter TIPSs were created using varied human TIPS access sets without adverse events, both sheathed and unsheathed advancement and deployment of the devices within liver tracts. One animal was sacrificed at 35 days due to encephalopathy; the remainder survived to endpoints. Twenty-two of 24 TIPSs were patent at 30-day and 60-day endpoints. The mean stenosis at 30 days was 13.3% (SD ± 10.1), and that at 60 days was 18.4% (SD ± 5.0). Two shunts were occluded by tissue overgrowth at the stent-free native hepatic vein end and downgrowth into TIPS. Histology and electron microscopy showed well-apposed, incorporated devices lined with smooth, uniform neointimal tissue averaging 0.48 mm (single devices) and 0.74 mm (overlapped devices) thick with minimal adventitial inflammation. Conclusions: The new Liverty TIPS stent graft was straightforward to deploy for TIPS creation and resulted in patent 6-mm-diameter, 7-mm-diameter, and 10-mm-diameter shunts in both single and overlapping configurations. One- and 2-month histology showed desired tissue healing without in-stent stenosis.