title: Factors affecting anatomical changes after endovascular abdominal aortic aneurysm repair.
abstract: BACKGROUND
  The primary goal of endovascular aneurysm repair (EVAR) is to prevent death from aneurysm rupture. Regression of aortic sac size is believed to be a marker for success after EVAR. This study analyzes the changes in aneurysm sac size and the factors affecting sac regression after EVAR.
  
  
  METHODS
  We retrospectively reviewed 121 patients with abdominal aortic aneurysm (AAA) who underwent elective treatment with EVAR at our institution from January 2005 to December 2011. In this study, 17 of the 121 patients were excluded due to loss during follow-up or for not having undergone a postoperative computed tomographic (CT) scan, and 3 patients were excluded due to an isolated iliac artery aneurysm. CT scans were scheduled at months 1, 6, and 12, and annually thereafter. Aneurysm size was defined by the minor axis on the largest axial cut of the aneurysm on a two-dimensional CT scan. Sac regression was defined as a reduction in the diameter of more than 5 mm.
  
  
  RESULTS
  Sac regression was observed during follow-up in 39 of the 101 patients. There was 1 regression in 87 patients (1%) at 1 month, 18 in 62 patients at 6 months (29%), 26 regressions in 44 patients (59%) at 12 months, and 18 regressions in 34 patients (53%) at 24 months. After multivariate analysis, the absence of endoleaks was the only factor associated with sac regression (hazard ratio, 3.620; confidence interval, 1.692-7.747; p = 0.001).
  
  
  CONCLUSIONS
  Sac regression over 5 mm is associated with current or previous endoleaks after EVAR. Continued surveillance is necessary in all patients after EVAR to prevent late complications.
authors.affiliation: Division of Vascular Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Keun-Myoung
authors.initials: KM
authors.lastname: Park
authors.affiliation: Division of Vascular Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Dong-Ik
authors.initials: DI
authors.lastname: Kim
authors.affiliation: Division of Vascular Surgery, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Young-Wook
authors.initials: YW
authors.lastname: Kim
authors.affiliation: Department of Radiology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Young-Soo
authors.initials: YS
authors.lastname: Do
authors.affiliation: Department of Radiology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Hong Suk
authors.initials: HS
authors.lastname: Park
authors.affiliation: Department of Radiology, Sungkyunkwan University School of Medicine, Samsung Medical Center, Seoul, Republic of Korea.
authors.forename: Kwang Bo
authors.initials: KB
authors.lastname: Park
mesh_terms: D000368:Aged; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000601:surgery*; D001027:Aortography / Q000379:methods; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects; D057867:Endoleak / Q000175:diagnosis / Q000209:etiology; D057510:Endovascular Procedures / Q000009:adverse effects; D005260:Female; D006801:Humans; D008297:Male; D012189:Retrospective Studies; D012307:Risk Factors; D013624:Taiwan; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D066253:Vascular Remodeling