title: Use of nitinol stents following recanalization of central venous occlusions in hemodialysis patients.
abstract: OBJECTIVE
  To retrospectively review the patency of endovascular interventions with nitinol stent placement for symptomatic central venous occlusions in hemodialysis patients.
  
  
  METHODS
  A retrospective review of all patients who underwent endovascular interventions for dysfunctional hemodialysis grafts and fistulas was performed from April 2004 to August 2006. A total of 6 patients presented with arm and/or neck and facial swelling and left brachiocephalic vein occlusion. The study group consisted of 3 men and 3 women with a mean age of 79.5 years (SD 11.2 years). Of these 6 patients, 1 had a graft and 5 had fistulas in the left arm. The primary indication for nitinol stent placement was technical failure of angioplasty following successful traversal of occluded central venous segments. Patency was assessed from repeat fistulograms and central venograms performed when patients redeveloped symptoms or were referred for access dysfunction determined by the ultrasound dilution technique. No patients were lost to follow-up.
  
  
  RESULTS
  Nitinol stent placement to obtain technically successful recanalization of occluded venous segments was initially successful in 5 of 6 patients (83%). In 1 patient, incorrect stent positioning resulted in partial migration to the superior vena cava requiring restenting to prevent further migration. Clinical success was observed in all patients (100%). Over the follow-up period, 2 patients underwent repeat intervention with angioplasty alone. Primary patency was 83.3% (95% CI 0.5-1.2) at 3 months, and 66.7% at 6 and 12 months (0.2-1.1, 0.1-1.2). Secondary patency was 100% at 12 months with 3 patients censored over that time period. Mean primary patency was 10.4 months with a mean follow-up of 12.4 months. No complications related to recanalization of the occluded central venous segments were observed.
  
  
  CONCLUSIONS
  Our initial experience has demonstrated that use of nitinol stents for central venous occlusion in hemodialysis patients is associated with good mid-term patency and may exceed historical observations with prior use of Wallstents.
authors.affiliation: Division of Vascular and Interventional Radiology, Department of Medical Imaging, Toronto General Hospital, University Health Network University of Toronto, M5G 2N2, Toronto, Ontario, Canada. dheeraj.rajan@uhn.on.ca
authors.forename: Dheeraj K
authors.initials: DK
authors.lastname: Rajan
authors.forename: Jasdeep S
authors.initials: JS
authors.lastname: Saluja
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000497:Alloys; D001166:Arteriovenous Shunt, Surgical; D016121:Brachiocephalic Veins; D003097:Collateral Circulation / Q000502:physiology; D004867:Equipment Design; D005260:Female; D005542:Forearm / Q000098:blood supply*; D006083:Graft Occlusion, Vascular / Q000000981:diagnostic imaging / Q000628:therapy*; D006801:Humans; D007676:Kidney Failure, Chronic / Q000000981:diagnostic imaging / Q000628:therapy*; D008297:Male; D010690:Phlebography; D011138:Polytetrafluoroethylene; D006435:Renal Dialysis; D012189:Retrospective Studies; D015607:Stents
chemical_list: D000497:Alloys; C013616:nitinol; D011138:Polytetrafluoroethylene