title: Influence of warfarin therapy on the occurrence of postoperative endoleaks and aneurysm sac enlargement after endovascular abdominal aortic aneurysm repair.
abstract: This study aims to determine whether warfarin therapy influences the occurrence of endoleaks or aneurysm sac enlargement after endovascular aortic repair (EVAR).
  
  
  
  A total of 367 patients who underwent EVAR for abdominal aortic aneurysm between 2007 and 2013 were recruited for this study. Satisfactory follow-up data including completed computed tomography scan follow-up for more than 2 years were available for 209 patients, and the mean follow-up time was 37 ± 12 months. Twenty-nine (16%) patients were on warfarin therapy (warfarin group), whereas 180 (84%) patients were not on warfarin therapy (control group).
  
  
  
  Two- and four-year freedom rates for persistent type II endoleaks were significantly lower in patients of the warfarin group compared with the control group (85 and 49% vs 93 and 91%, respectively; P = 0.0001). Similarly, 2- and 4-year freedom rates for sac enlargement (>5 mm) were significantly lower in patients of the warfarin group compared with the control group (83 and 61% vs 92 and 82%, respectively; P = 0.0036). Using Cox regression analysis, the warfarin therapy was identified to be an independent positive predictor of sac enlargement after EVAR [hazard ratio (HR): 2.4; 95% confidence interval (CI): 1.08-5.40; P = 0.032], together with persistent type II endoleak. Warfarin therapy was also an independent predictor for persistent type II endoleak (HR: 3.7; 95% CI: 1.81-7.41; P < 0.0001) together with the number of patent lumbar arteries.
  
  
  
  Results suggested that warfarin therapy was significantly associated with an increased risk for persistent II endoleak and sac enlargement after EVAR.
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Yoshimasa
authors.initials: Y
authors.lastname: Seike
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tanaka
authors.affiliation: Department of Radiology, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Fukuda
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Itonaga
authors.affiliation: Department of Radiology, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Yoshiaki
authors.initials: Y
authors.lastname: Morita
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Oda
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Inoue
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Sasaki
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Minatoya
authors.affiliation: Department of Cardiovascular Surgery, National Cerebral and Cardiovascular Center, Osaka, Japan.
authors.forename: Junjiro
authors.initials: J
authors.lastname: Kobayashi
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000627:therapeutic use*; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology* / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D057867:Endoleak / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications / Q000209:etiology*; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D000925:Anticoagulants; D014859:Warfarin
keywords: Abdominal aortic aneurysm; Endovascular aneurysm repair; Persistent type II endoleak; Sac enlargement; Warfarin therapy