title: Predictors of abdominal aortic aneurysm sac enlargement after endovascular repair.
abstract: BACKGROUND
  The majority of infrarenal abdominal aortic aneurysm (AAA) repairs in the United States are performed with endovascular methods. Baseline aortoiliac arterial anatomic characteristics are fundamental criteria for appropriate patient selection for endovascular aortic repair (EVAR) and key determinants of long-term success. We evaluated compliance with anatomic guidelines for EVAR and the relationship between baseline aortoiliac arterial anatomy and post-EVAR AAA sac enlargement.
  
  
  RESULTS
  Patients with pre-EVAR and at least 1 post-EVAR computed tomography scan were identified from the M2S, Inc. imaging database (1999 to 2008). Preoperative baseline aortoiliac anatomic characteristics were reviewed for each patient. Data relating to the specific AAA endovascular device implanted were not available. Therefore, morphological measurements were compared with the most liberal and the most conservative published anatomic guidelines as stated in each manufacturer's instructions for use. The primary study outcome was post-EVAR AAA sac enlargement (>5-mm diameter increase). In 10 228 patients undergoing EVAR, 59% had a maximum AAA diameter below the 55-mm threshold at which intervention is recommended over surveillance. Only 42% of patients had anatomy that met the most conservative definition of device instructions for use; 69% met the most liberal definition of device instructions for use. The 5-year post-EVAR rate of AAA sac enlargement was 41%. Independent predictors of AAA sac enlargement included endoleak, age ≥ 80 years, aortic neck diameter ≥ 28 mm, aortic neck angle >60°, and common iliac artery diameter >20 mm.
  
  
  CONCLUSIONS
  In this multicenter observational study, compliance with EVAR device guidelines was low and post-EVAR aneurysm sac enlargement was high, raising concern for long-term risk of aneurysm rupture.
authors.affiliation: Division of Vascular and Endovascular Surgery, Department of Quantitative Health Sciences, U Mass Memorial Medical Center, 55 Lake Ave North, Worcester, MA 01655, USA. schanzea@ummhc.org
authors.forename: Andres
authors.initials: A
authors.lastname: Schanzer
authors.forename: Roy K
authors.initials: RK
authors.lastname: Greenberg
authors.forename: Nathanael
authors.initials: N
authors.lastname: Hevelone
authors.forename: William P
authors.initials: WP
authors.lastname: Robinson
authors.forename: Mohammad H
authors.initials: MH
authors.lastname: Eslami
authors.forename: Robert J
authors.initials: RJ
authors.lastname: Goldberg
authors.forename: Louis
authors.initials: L
authors.lastname: Messina
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000465:Algorithms; D001012:Aorta, Abdominal / Q000473:pathology; D017544:Aortic Aneurysm, Abdominal / Q000453:epidemiology / Q000473:pathology* / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects* / Q000592:standards / Q000706:statistics & numerical data; D003198:Computer Simulation; D005260:Female; D005500:Follow-Up Studies; D019983:Guideline Adherence / Q000706:statistics & numerical data; D006801:Humans; D007083:Iliac Artery / Q000473:pathology; D008297:Male; D008955:Models, Cardiovascular; D011183:Postoperative Complications / Q000453:epidemiology / Q000473:pathology*; D011237:Predictive Value of Tests; D012307:Risk Factors