title: The impact of endovascular aneurysm repair on aortoiliac tortuosity and its use as a predictor of iliac limb complications.
abstract: OBJECTIVE
  Aortoiliac tortuosity is often cited subjectively as a causative factor in iliac limb complications after endovascular aneurysm repair (EVAR); however, evidence on this subject is poor. The aim of this study was to investigate the impact of stent grafting on aortoiliac tortuosity and to explore the role of the tortuosity index (TI) as a predictor of iliac limb complications after EVAR.
  
  
  METHODS
  A retrospective case-control study was performed comparing an iliac limb complication group with a control group. Reconstructed computed tomography angiography images were analyzed to calculate TI of the aortoiliac segments.
  
  
  RESULTS
  This study included 153 patients, 120 in the control groups (40 Zenith flex [Cook Medical, Bloomington, Ind], 40 Endurant II [Medtronic, Minneapolis, Minn], and 40 Excluder [W. L. Gore and Associates, Flagstaff, Ariz] stent grafts) and 33 in the complications group (13 Zenith flex, 14 Endurant II, 4 Excluder, and 2 Aorfix [Lombard Medical, Oxfordshire, UK] stent grafts). There was a significant reduction in aortic and iliac TI after EVAR. This was greatest with the Zenith Flex compared with Endurant, with the least change in TI seen after Gore Excluder implantation. Iliac limb complications included 10 type Ib endoleaks, one iliac limb modular dislocation, two limbs with insufficient engagement, four occlusions, and 16 iliac limb kinks. There was no significant difference in complication rates between the three stent grafts (Zenith flex, 1.4%; Endurant, 2.9%; Excluder, 1.9%; P = .115). The median time to iliac complication was 14 months (range, 1-90 months). The iliac limb complication group was found to have a significantly increased aortoiliac TI on both preoperative and postoperative computed tomography imaging.
  
  
  CONCLUSIONS
  EVAR has a significant effect on aortoiliac tortuosity. Despite the reduction of aortoiliac tortuosity after the insertion of a stent graft, TI may serve as a predictor of iliac limb complications after EVAR.
authors.affiliation: Liverpool Vascular and Endovascular Service, Royal Liverpool Hospital, Liverpool, United Kingdom. Electronic address: jamescoulston@yahoo.co.uk.
authors.forename: James
authors.initials: J
authors.lastname: Coulston
authors.affiliation: Liverpool Vascular and Endovascular Service, Royal Liverpool Hospital, Liverpool, United Kingdom.
authors.forename: Amy
authors.initials: A
authors.lastname: Baigent
authors.affiliation: Department of Surgical Science, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Haran
authors.initials: H
authors.lastname: Selvachandran
authors.affiliation: Liverpool Vascular and Endovascular Service, Royal Liverpool Hospital, Liverpool, United Kingdom; Department of Surgical Science, University of Liverpool, Liverpool, United Kingdom.
authors.forename: Steven
authors.initials: S
authors.lastname: Jones
authors.affiliation: Liverpool Vascular and Endovascular Service, Royal Liverpool Hospital, Liverpool, United Kingdom.
authors.forename: Francesco
authors.initials: F
authors.lastname: Torella
authors.affiliation: Liverpool Vascular and Endovascular Service, Royal Liverpool Hospital, Liverpool, United Kingdom.
authors.forename: Robert
authors.initials: R
authors.lastname: Fisher
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001014:Aortic Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation; D057867:Endoleak / Q000209:etiology; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation; D006083:Graft Occlusion, Vascular / Q000209:etiology; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D011474:Prosthesis Design; D012189:Retrospective Studies; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome