title: A flexible stent with small intestinal submucosa covering for direct intrahepatic portocaval shunt: experimental pilot study in swine.
abstract: The suitability of the flexible sandwich Zilver stent-graft (SZSG) with a biologically active tissue layer (small intestinal submucosa) for creation of the intravascular ultrasound (IVUS)-guided direct intrahepatic portocaval shunt (DIPS) was explored in six young swine in a search for a flexible system to replace the rigid polytetrafluoroethylene (PTFE) stent originally used by this group with limited success. The portal vein was punctured from the inferior vena cava through the caudate lobe of the liver using IVUS guidance. After balloon dilation of the puncture tract, DIPS was successfully created in all animals with use of an SZSG 9 mm in diameter and 6 cm or 8 cm long. Only one DIPS remained well patent at 14 days when the animal had to be killed because of encephalopathy. DIPS in the other five animals were found to be either severely stenosed (3 animals) or occluded (2 animals) at 4 weeks due to accelerated formation of neointimal hyperplasia (NIH) in the liver parenchymal portion of the shunt and superimposed thrombosis. The lack of high pressure in the portal system contributed to early endograft closure. The flexible stent and the covering fail badly. The reason for this could be due to either component. More work is required to find a reliable flexible system with long-term patency. Exploration of the IVUS-guided direct extrahepatic portocaval shunt is suggested.
authors.affiliation: Dotter Interventional Institute, Oregon Health & Science University L342, 3181 SW Sam Jackson Park Road, Portland, OR 97239, USA.
authors.forename: Mahtab
authors.initials: M
authors.lastname: Niyyati
authors.forename: Bryan D
authors.initials: BD
authors.lastname: Petersen
authors.forename: Dusan
authors.initials: D
authors.lastname: Pavcnik
authors.forename: Barry T
authors.initials: BT
authors.lastname: Uchida
authors.forename: Hans A
authors.initials: HA
authors.lastname: Timmermans
authors.forename: Takao
authors.initials: T
authors.lastname: Hiraki
authors.forename: Reng-Hong
authors.initials: RH
authors.lastname: Wu
authors.forename: Elias
authors.initials: E
authors.lastname: Brountzos
authors.forename: Frederick S
authors.initials: FS
authors.lastname: Keller
authors.forename: Josef
authors.initials: J
authors.lastname: Rösch
mesh_terms: D000818:Animals; D001705:Bioprosthesis; D002404:Catheterization; D004195:Disease Models, Animal; D019160:Endosonography; D004867:Equipment Design; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology; D006965:Hyperplasia; D010865:Pilot Projects; D018583:Pliability; D011169:Portal Vein / Q000473:pathology / Q000601:surgery; D019168:Portasystemic Shunt, Transjugular Intrahepatic / Q000295:instrumentation*; D015607:Stents; D013552:Swine; D013927:Thrombosis / Q000209:etiology; D013997:Time Factors; D017539:Tunica Intima / Q000473:pathology; D018084:Ultrasonography, Interventional; D014654:Vascular Patency; D014682:Vena Cava, Inferior / Q000473:pathology / Q000601:surgery