Creation of transjugular intrahepatic portosystemic shunts with use of the Cragg Endopro System I

SINCE its introduction in 1989 (1), the transjugular intrahepatic portosystemic shunt (TIPS) procedure has gained wide acceptance and is now an established therapeutic alternative in the management of the patients with hemorrhagic portal hypertension (2,3). Recently published data have confirmed that TIPS malfunction caused by shunt stenosis or occlusion is a frequent problem (4-6). Shunt malfunction is associated with recurrent variceal bleeding and, in some cases, reaccumulation of ascitic fluid (4-6). To maintain shunt patency, repeated revisions with use of recanalization techniques, balloon dilation, or additional stent placement are necessary (4- 6). The causes and mechanisms for the development of shunt stenoses or occlusions are poorly understood. Acute shunt occlusion may be related to stent recoil (4), stent misplacement, or to portal vein thrombosis. Stenosis at the hepatic vein end of the shunt may be related to the development of intimal hyperplasia or to stent compression by regeneration nodules. The tissue reaction involved in midshunt stenoses was initially described as 'pseudointimal' hyperplasia, and histopathologic analysis revealed that it is composed mainly of collagen-rich granulation tissue, myofibroblasts, and 'endothelial-like' cells (7). In this initial study, bile staining was described as part of the pseudointimal reaction in three of five cases and the possibility of an association between bile duct injuries and the development of shunt stenoses or occlusions was proposed (7). In a later study, Saxon et al demonstrated severe stenosis or occlusion in 48% of human TIPS and in 77%of experimental swine shunts (8). These investigators found grogs or histologic evidence of a substantial biliary fistula in a significant number of shunts with severe parenchymal tract stenoses or occlusions (8). These results provide a useful background to justify the use of stent-grafts to create TIPS in an attempt to isolate or exclude the leakage of bile into the shunt and, thus, decrease the magnitude of the pseudointimal reaction, improving the shunt's patency. We conducted a prospective study to assess the feasibility and safety of creating TIPS with a specially designed stent-graft.