title: Late Sac Behavior after Endovascular Aneurysm Repair for Abdominal Aortic Aneurysm.
abstract: BACKGROUND
  Sac behavior after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysms (AAAs) is considered as a surrogate for the risk of late rupture. The purpose of the study is to assess the sac behavior of AAAs after EVAR.
  
  
  RESULTS
  Late sac enlargement (LSE) (≥5 mm) and late sac shrinkage (LSS) (≥5 mm) were analyzed in 589 consecutive patients who were registered at 14 national centers in Japan. The proportions of patients who had LSE at 1, 3 and 5 years were 2.6% ± 0.7%, 10.0% ± 1.6% and 19.0% ± 2.9%. The proportions of patients who had LSS at 1, 3 and 5 years were 50.1% ± 0.7%, 59.2% ± 2.3% and 61.7% ± 2.7%. Multiple logistic regression analysis identified two variables as a risk factor for LSE; persistent endoleak (Odds ratio 9.56 (4.84-19.49), P <0.001) and low platelet count (Odds ratio 0.92 (0.86-0.99), P = 0.0224). The leading cause of endoleak in patients with LSE was type II.
  
  
  CONCLUSIONS
  The incidence of LSE is not negligible over 5 year period. Patients with persistent endoleak and/or low platelet count should carefully be observed for LSE.
  
  
  BACKGROUND
  UMIN-CTR (UMIN000008345).
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Okada
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Nobuhiro
authors.initials: N
authors.lastname: Handa
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Toshihiro
authors.initials: T
authors.lastname: Onohara
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Minoru
authors.initials: M
authors.lastname: Okamoto
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Yamamoto
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Shimoe
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Masafumi
authors.initials: M
authors.lastname: Yamashita
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takahashi
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Jyunji
authors.initials: J
authors.lastname: Kishimoto
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Akihiro
authors.initials: A
authors.lastname: Mizuno
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Junichi
authors.initials: J
authors.lastname: Kei
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Mikizou
authors.initials: M
authors.lastname: Nakai
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Sakaki
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Suhara
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Fuminori
authors.initials: F
authors.lastname: Kasashima
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Endo
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Nishina
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Tadashi
authors.initials: T
authors.lastname: Furuyama
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Masakazu
authors.initials: M
authors.lastname: Kawasaki
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Keiji
authors.initials: K
authors.lastname: Iwata
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Akira
authors.initials: A
authors.lastname: Marumoto
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Urata
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Katsutoshi
authors.initials: K
authors.lastname: Sato
authors.affiliation: Office of Medical Devices, Pharmaceuticals and Medical Devices Agency, Tokyo, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ryugo
keywords: abdominal aortic aneurysm; endoleak; endovascular aneurysm repair; late rupture; sac behavior