title: Evaluating patency rates of an ultralow-porosity expanded polytetrafluoroethylene covered stent in the treatment of venous stenosis in arteriovenous dialysis circuits.
abstract: OBJECTIVE
  To evaluate the efficacy of an ultralow-porosity expanded polytetrafluoroethylene (ePTFE) covered stent in the treatment of autogenous arteriovenous fistula (AVF) and prosthetic arteriovenous graft (AVG) venous outflow stenoses.
  
  
  METHODS
  Clinical and angiographic outcomes of 20 consecutive patients with arteriovenous dialysis circuits treated with the endoprosthesis were reviewed following institutional review board approval. Patients were followed routinely at 2 months and 6 months after stent placement, or earlier if clinically warranted. The primary endpoint was 2- and 6-month primary treatment area patency. Secondary endpoints included primary circuit patency, primary assisted patency, and secondary patency.
  
  
  RESULTS
  Eleven patients with AVFs and nine patients with AVGs were treated successfully with the covered stent. Primary treatment area patency rates were 85% ± 16 at both 2 months and 6 months. Primary circuit patency rates were was 65% ± 21 and 45% ± 22, respectively; primary assisted patency rates were 90% ± 13 and 85% ± 16, respectively; and secondary patency rates were 100% and 90% ± 13, respectively. Of the three cases of lost primary treatment area patency, two developed thrombosis and one developed recurrent stenosis. No significant differences were found between patients with AVFs and AVGs.
  
  
  CONCLUSIONS
  Data from this preliminary study suggests that the ultralow-porosity ePTFE covered stent may be a clinically viable option for treatment of venous outflow stenoses in arteriovenous vascular access circuits.
authors.affiliation: Department of Radiology, University of California, Los Angeles, Los Angeles; Department of Radiology, University of California, San Diego, San Diego, California.
authors.forename: Michael G
authors.initials: MG
authors.lastname: Chan
authors.affiliation: Department of Radiology, University of California, San Diego, San Diego, California.
authors.forename: Franklin J
authors.initials: FJ
authors.lastname: Miller
authors.affiliation: Department of Radiology, University of Washington, Seattle, Washington.
authors.forename: Karim
authors.initials: K
authors.lastname: Valji
authors.affiliation: Department of Radiology, University of California, Los Angeles, Los Angeles.
authors.forename: Anshuman
authors.initials: A
authors.lastname: Bansal
authors.affiliation: Department of Radiology, University of California, Los Angeles, Los Angeles. Electronic address: michaelkuo@mednet.ucla.edu.
authors.forename: Michael D
authors.initials: MD
authors.lastname: Kuo
mesh_terms: D000328:Adult; D000368:Aged; D000800:Angioplasty, Balloon / Q000009:adverse effects / Q000295:instrumentation*; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000295:instrumentation*; D005260:Female; D006083:Graft Occlusion, Vascular / Q000175:diagnosis / Q000209:etiology / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011138:Polytetrafluoroethylene; D016062:Porosity; D011474:Prosthesis Design; D012008:Recurrence; D006435:Renal Dialysis; D015607:Stents; D013927:Thrombosis / Q000209:etiology / Q000628:therapy; D013997:Time Factors; D016896:Treatment Outcome; D014654:Vascular Patency
chemical_list: D011138:Polytetrafluoroethylene
keywords: AVF; AVG; FDA; Food and Drug Administration; VAC; arteriovenous fistula; arteriovenous graft; ePTFE; expanded polytetrafluoroethylene; vascular access circuit