title: The longevity of arteriovenous graft for hemodialysis patients--externally supported or nonsupported.
abstract: OBJECTIVE
  Because thrombosis and stenosis are the most frequent causes of arteriovenous graft (AVG) failure, several externally supported grafts were designed to enhance incompressibility and kinking resistance to improve the patency. However, consensus on advantage of these modifications having still not been reached might relate to the previous limited patient numbers and small studies. This study analyzed the longevity of externally supported and nonsupported AVG on the basis of the nationwide database to understand whether the externally supported design could improve the duration of patency of AVG.
  
  
  METHODS
  Adult incident patients (n = 4402) were retrospectively enrolled who had began hemodialysis between January 1, 2002 and December 31, 2005. All incident patients with AVG, before or after beginning regular hemodialysis, between January 1, 2000 and December 31, 2006 were identified. The Cox proportional hazard model was used to compare the longevity of externally supported and nonsupported AVG by controlling other covariates.
  
  
  RESULTS
  There were 990 patients with externally supported AVG and 3412 patients with nonsupported AVG. The patency rates of externally supported AVG were 49.4%, 31.6%, and 20.2% at 1, 2 and 3 years, respectively; those of nonsupported AVG were 31.9%, 17.4%, and 10.8%. The survival of nonsupported AVG was significantly inferior to that of externally supported AVG.
  
  
  CONCLUSIONS
  Externally supported AVG are superior to nonsupported AVG for long-term patency. The incompressibility and kinking resistance of ringed grafts may shed light on a direction for the future development of dialysis graft design.
authors.affiliation: Institute of Health and Welfare Policy, School of Medicine, National Yang-Ming University, Taipei, Taiwan.
authors.forename: Yen-Ni
authors.initials: YN
authors.lastname: Hung
authors.forename: Po-Jen
authors.initials: PJ
authors.lastname: Ko
authors.forename: Yee-Yung
authors.initials: YY
authors.lastname: Ng
authors.forename: Shiao-Chi
authors.initials: SC
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001166:Arteriovenous Shunt, Surgical / Q000009:adverse effects / Q000295:instrumentation; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation; D016009:Chi-Square Distribution; D005260:Female; D006083:Graft Occlusion, Vascular / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D006435:Renal Dialysis; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013624:Taiwan; D013997:Time Factors; D016896:Treatment Outcome; D034941:Upper Extremity / Q000098:blood supply*; D014654:Vascular Patency; D055815:Young Adult