In the management of cirrhotic patients with variceal bleeding, transjugular intra-hepatic portosystemic shunt (TIPS) plays an important role in decompressing the portal system and preventing the danger of frequent rebleeding. The advance of this less invasive, non-surgical approach of portal decompression was made possible through the clinical introduction of vascular stents. At first, balloon expandable stents, such as Palmaz stents or Tantalum Strecker stents were employed in TIPS procedure, however, in time, many switched to self-expanding stents such as Wallstent, Nitinol Stecker stents, Memotherm stents, or GianturcolRosch stents, which became more popular due to their easier deployment and variety of size available. However, there are intrinsic differences among all self-expanding stents regarding elasticity, length, diameter, longitudinal flexibility hoop strength, mesh profile, and delivery system, which influence their performance. Despite the clinical success of TIPS to date, several major challenges remain. Early malfunction of TIPS may occur due to tract closure resulting from bioleakage intralumina! thrombosis, incomplete stent expansion, or stent migration. More commonly, TIPS patency is compromised progressively in the months following placement due to tissue in-growth. These and other limitations of current TIPS practice must be resolved to ensure durable patency and efficacy rates for TIPS. It is the specific objective of this Phase I project to resolve some of these limitations through introduction of a composite nitinol stent combined with in adherent polymeric endoluminal layer. Berkeley Applied Science & Engineering, Inc. (BASE) has developed a unique expertise in using nitinol for various industrial and medical applications. The co-investigator, Dr. Slepian, was the original inventor and developer of polymeric endoluminal paving. During Phase l.a combination of strengths will be utilized, including mathematical simulation of BASE and the polymeric expertise of the Slepian lab. Prototype stent samples will be fabricated and a limited animal study will be done to demonstrate how present limitations of TIPS procedure can be improved
