title: Adjunctive iliac stents reduce the risk of stent-graft limb occlusion following endovascular aneurysm repair with the Zenith stent-graft.
abstract: OBJECTIVE
  To determine whether the introduction of a policy of adjunctive stent insertion based on preoperative CT assessment or completion angiography reduced the incidence of limb occlusion after stent-graft implantation for endovascular aneurysm repair (EVAR).
  
  
  METHODS
  A tertiary referral unit's endovascular database was retrospectively interrogated to compare the incidence of endograft limb occlusion in Zenith grafts following the introduction of a policy of selective adjunctive stent insertion. Group A included 288 limbs at risk in 146 patients (134 men; mean age 74+/-8 years) treated prior to August 2005 in whom adjunctive stents were inserted on an ad hoc basis only. Group B included 293 limbs at risk in 149 patients (127 men; mean age 76+/-7 years) treated after this date in whom a more aggressive adjunctive stenting strategy was adopted. Kaplan-Meier analysis was employed to compare outcomes.
  
  
  RESULTS
  In total, 295 patients underwent EVAR involving 581 iliac vessels, of which 11 (1.8%) occluded at a median of 24 months (0-27). Of 65 limbs extended into the external iliac segment, 5 (7.6%) subsequently occluded; in the remaining 516 limbs, there were 6 (1.1%) occlusions (p = 0.004). Across the study group, 38 (6.5%) adjunctive stents were deployed in limbs deemed at risk; 1 (2.6%) of these occluded. In the remaining 543 unstented limbs, 10 (1.8%) occlusions occurred (p = 0.15). There were 11 occlusions in group A, in which 5 (1.7%) adjunctive stents had been deployed, but none in group B, which had received 33 (11.2%) stents (p<0.0001). Kaplan-Meier survival curves identified primary patency rates at 36 months of 96% and 100%, respectively (p = 0.001).
  
  
  CONCLUSIONS
  Adjunctive stenting significantly reduces the risk of postoperative stent-graft limb occlusion without obvious compromise to the aneurysm repair.
authors.affiliation: Regional Vascular Unit and, Royal Liverpool University Hospital, Liverpool L7 8XP, UK.
authors.forename: Olufemi A
authors.initials: OA
authors.lastname: Oshin
authors.forename: Robert K
authors.initials: RK
authors.lastname: Fisher
authors.forename: Leith A
authors.initials: LA
authors.lastname: Williams
authors.forename: John A
authors.initials: JA
authors.lastname: Brennan
authors.forename: Geoffrey L
authors.initials: GL
authors.lastname: Gilling-Smith
authors.forename: S Rao
authors.initials: SR
authors.lastname: Vallabhaneni
authors.forename: Richard G
authors.initials: RG
authors.lastname: McWilliams
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; 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 / Q000517:prevention & control*; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D053208:Kaplan-Meier Estimate; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome