title: Aortoiliac elongation after endovascular aortic aneurysm repair.
abstract: BACKGROUND
  Aortoiliac elongation after endovascular aortic aneurysm repair (EVAR) is not well studied. We sought to assess the long-term morphologic changes after EVAR and identify potentially modifiable factors associated with such a change.
  
  
  METHODS
  An institutional review board-approved retrospective review was conducted for 88 consecutive patients who underwent EVAR at a single academic center from 2003 to 2007 and who also had at least 2 follow-up computed tomography angiograms (CTAs) available for review up to 5 years after surgery. Standardized centerline aortic lengths and diameters were obtained on Aquarius iNtuition 3D workstation (TeraRecon Inc., San Mateo, CA) on postoperative and all-available follow-up CTAs. Relationships to aortic elongation were determined using Wilcoxon rank-sum test or linear regression (Stata version 12.1, College Station, TX). Changes in length over time were determined by mixed-effects analysis (SAS version 9.3, Cary, NC).
  
  
  RESULTS
  The study cohort was composed of mostly men (88%), with a mean age of (76 ± 8) and a mean follow-up of 3.2 years (range, 0.4-7.5 years). Fifty-seven percent of patients (n = 50) had devices with suprarenal fixation and 43% (n = 38) had no suprarenal fixation. Significant lengthening was observed over the study period in the aortoiliac segments, but not in the iliofemoral segments. Aortoiliac elongation over time was not associated with sex (P = 0.3), hypertension (P = 0.7), coronary artery disease (P = 0.3), diabetes (P = 0.3), or tobacco use (P = 0.4), but was associated with the use of statins (P = 0.03) and the presence of chronic obstructive pulmonary disease (P = 0.02). Significant aortic lengthening was associated with increased type I endoleaks (P = 0.03) and reinterventions (P = 0.03). Over the study period, 4 different devices were used; Zenith (Cook Medical Inc., Bloomington, IN), Talent (Medtronic, Minneapolis, MN), Aneuryx (Medtronic), and Excluder (W. L. Gore and Associates Inc., Flagstaff, AZ). After adjusting for differences in proximal landing zone, significant differences in aortic lengthening over time were observed by device type (P = 0.02).
  
  
  CONCLUSIONS
  Significant aortoiliac elongation was observed after EVAR. Such morphologic changes may impact long-term durability of EVAR, warranting further investigation into factors associated with these morphologic changes.
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, CA. Electronic address: vchandra@stanford.edu.
authors.forename: Venita
authors.initials: V
authors.lastname: Chandra
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, CA.
authors.forename: Martin
authors.initials: M
authors.lastname: Rouer
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, CA.
authors.forename: Trit
authors.initials: T
authors.lastname: Garg
authors.affiliation: Division of Radiology, Stanford University Medical Center, Stanford, CA.
authors.forename: Dominik
authors.initials: D
authors.lastname: Fleischmann
authors.affiliation: Division of Vascular Surgery, Stanford University Medical Center, Stanford, CA.
authors.forename: Matthew
authors.initials: M
authors.lastname: Mell
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001011:Aorta / Q000473:pathology / Q000601:surgery*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D057867:Endoleak / Q000209:etiology; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D021621:Imaging, Three-Dimensional; D016014:Linear Models; D008297:Male; D011183:Postoperative Complications / Q000000981:diagnostic imaging / Q000209:etiology*; D011237:Predictive Value of Tests; D011857:Radiographic Image Interpretation, Computer-Assisted; D012189:Retrospective Studies; D012307:Risk Factors; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome