title: Transjugular intrahepatic portosystemic shunt (TIPS). Thrombogenicity in stents and its effect on shunt patency.
abstract: OBJECTIVE
  To compare the thrombogenicity and patency of the Palmaz stent and the Wallstent, and to evaluate the effect of periprocedural heparin therapy in cirrhotic patients with maintained coagulation capacity who receive a transjugular intrahepatic portosystemic shunt (TIPS).
  
  
  METHODS
  Twenty-four patients were randomized into 4 groups of 6 patients. Each received a Palmaz-stent or Wallstent TIPS with or without periprocedural heparin therapy. The groups receiving periprocedural heparin were given 24 U/kg b.w. just before stent placement, followed by 24 h therapeutic i.v. heparin. After 24 hours, all patients received i.v. heparin for 1 week followed by subcutaneous treatment with low-molecular-weight heparin (0.3 ml/day) for another 4 weeks. Stent thrombogenicity was determined scintigraphically after i.v. injection of 120-290 mBq of 99mTc-labeled platelets at the time of stent placement and expressed as the stent/heart ratio. Shunt patency was assessed by duplex sonography and confirmed radiologically.
  
  
  RESULTS
  The aggregation ratio was highest 90 min after stent implantation. Wallstents showed a significantly higher ratio than Palmaz stents. Heparin reduced the ratio in patients with a Wallstent (-41%) but had no effect on Palmaz stents. Patients with a Wallstent without heparin had a higher rate of early shunt insufficiency (66.6%) than the other patients (0-16.6%). Primary assisted long-term patency was similar in the 4 groups.
  
  
  CONCLUSIONS
  Wallstents were more thrombogenic than Palmaz stents and gave a significantly higher risk of early shunt insufficiency in cirrhotic patients with maintained coagulation capacity. Periprocedural heparin was effective in the prevention of shunt insufficiency and is therefore indicated in such patients.
authors.affiliation: Department of Gastroenterology, University Hospital, Freiburg, Germany.
authors.forename: V
authors.initials: V
authors.lastname: Siegerstetter
authors.forename: T
authors.initials: T
authors.lastname: Krause
authors.forename: M
authors.initials: M
authors.lastname: Rössle
authors.forename: K
authors.initials: K
authors.lastname: Haag
authors.forename: A
authors.initials: A
authors.lastname: Ochs
authors.forename: K H
authors.initials: KH
authors.lastname: Hauenstein
authors.forename: H E
authors.initials: HE
authors.lastname: Moser
mesh_terms: D000925:Anticoagulants / Q000627:therapeutic use*; D001792:Blood Platelets; D004932:Esophageal and Gastric Varices / Q000209:etiology / Q000601:surgery*; D005260:Female; D006471:Gastrointestinal Hemorrhage / Q000209:etiology / Q000601:surgery*; D006493:Heparin / Q000627:therapeutic use*; D006495:Heparin, Low-Molecular-Weight / Q000627:therapeutic use; D006801:Humans; D007430:Intraoperative Care; D008103:Liver Cirrhosis / Q000150:complications; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D010974:Platelet Aggregation; D011168:Portal System / Q000000981:diagnostic imaging / Q000503:physiopathology; D019168:Portasystemic Shunt, Transjugular Intrahepatic / Q000009:adverse effects / Q000295:instrumentation; D011182:Postoperative Care; D011877:Radionuclide Imaging; D015607:Stents; D019690:Technetium Tc 99m Exametazime; D013927:Thrombosis / Q000000981:diagnostic imaging / Q000453:epidemiology* / Q000517:prevention & control; D014463:Ultrasonography
chemical_list: D000925:Anticoagulants; D006495:Heparin, Low-Molecular-Weight; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D006493:Heparin