title: Intravascular ultrasound-guided direct intrahepatic portacaval shunt: description of technique and technical refinements.
abstract: OBJECTIVE
  This is a prospective study designed to demonstrate the safety and feasibility of creating a direct inferior vena cava (IVC)-to-portal vein shunt with use of a new type of intravascular ultrasound (IVUS) to guide the puncture and completing the shunt with the use of a polytetrafluoroethylene (PTFE)-covered stent graft.
  
  
  METHODS
  IVC-to-portal vein shunts were created in 31 sequential patients for ascites (n = 31) or bleeding (n = 8). Transfemorally placed IVUS transducers were positioned in the IVC to guide the puncture from the IVC to the portal vein, which was performed from a transjugular approach with a modified Rosch-Uchida liver access set. A 9-MHz axial imaging IVUS system was used for the first 11 patients, and a variable 5-10-MHz sagittal IVUS imaging system was used for the next 20 patients. The shunts were completed with the use of single (n = 11) or overlapping (n = 20) PTFE-covered Palmaz stent-grafts, deployed primarily at a diameter of 8 mm. Patients were followed clinically and with US, venography, and inspection at liver transplantation to establish 30-day patency rates.
  
  
  RESULTS
  All direct intrahepatic portacaval shunts (DIPSs) were created successfully. Both IVUS systems were able to adequately guide the portal vein puncture. Resolution and operator confidence were subjectively superior with the sagittal IVUS imaging system compared to the axial IVUS system. Two extrahepatic portal vein punctures occurred during the procedures. Both were controlled by the placement of sheaths and subsequent placement of stent-grafts. Both patients remained asymptomatic, although one required transfusion of blood products. The mean portosystemic gradient was reduced from 24 mm Hg before DIPS creation to 10 mm after DIPS creation. Embolization of varices was also performed in eight patients with history of recent gastrointestinal bleeding. Two patients died in the first week of acute liver failure. Two patients with hepatocellular carcinoma refused further follow-up. Of the 27 remaining patients, patency was demonstrated in all DIPS at 30 days by US, venography, or direct inspection at liver transplantation.
  
  
  CONCLUSIONS
  IVUS-guided direct IVC-to-portal vein shunts may be created successfully with minimal complications. The use of a stent-graft is recommended for this procedure. Modifications of current technique and IVUS systems are described.
authors.affiliation: Dotter Interventional Institute, Oregon Health and Sciences University, Portland, Oregon 97201, USA. Bryan.Petersen@med.va.gov
authors.forename: Bryan
authors.initials: B
authors.lastname: Petersen
mesh_terms: D000328:Adult; D000368:Aged; D001201:Ascites / Q000209:etiology / Q000601:surgery*; D006470:Hemorrhage / Q000209:etiology; D006801:Humans; D007431:Intraoperative Complications; D017093:Liver Failure / Q000150:complications; D008297:Male; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D011167:Portacaval Shunt, Surgical / Q000009:adverse effects / Q000295:instrumentation / Q000379:methods*; D011446:Prospective Studies; D011677:Punctures; D015607:Stents; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional; D014654:Vascular Patency
chemical_list: D011138:Polytetrafluoroethylene