title: Does chronic oral anticoagulation with warfarin affect durability of endovascular aortic aneurysm exclusion in a midterm follow-up?
abstract: OBJECTIVE
  To evaluate the effect of oral anticoagulation on durability of endovascular aortic aneurysm repair (EVAR).
  
  
  METHODS
  Retrospective review was conducted of 182 consecutive EVAR patients (169 men; mean age 75.3 years, range 53-89) between 1999 and 2003. Patients on warfarin anticoagulation (WA, n=21; International Normalized Ratio of 2 to 3) were compared against a control group (CG) with no postoperative anticoagulation (n=161). Death, aneurysm rupture, and reintervention were considered primary endpoints; endoleaks, endograft migration, and aneurysm remodeling were secondary endpoints.
  
  
  RESULTS
  Mean follow-up was 16.3+/-12.6 months. One-year mortality was 6.6% (9.5% WA versus 6.2% CG); overall mortality was 14.3% (p=0.414). No aneurysm rupture occurred. At 1, 2, and 3 years, respectively, cumulative reinterventions (20%/20%/20% WA versus 12%/15%/20% CG; p=0.633) and endoleak rates (25%/25%/25% WA versus 17%/22%/34% CG; p=0.649) were comparable. In both groups, most completion endoleaks resolved (42.9% WA versus 74.4% CG; p=0.474), but few de novo endoleaks did (0% WA versus 12.8% CG; p=0.538). Anticoagulation did not affect mean time to aneurysm sac shrinkage (1.3+/-0.3 WA versus 1.4+/-0.1 years CG; p=0.769).
  
  
  CONCLUSIONS
  After EVAR, anticoagulation appears safe and does not significantly alter mortality, risk for rupture, or the incidence of reintervention. Early endoleaks appear more common in anticoagulated patients, but anticoagulation does not preclude spontaneous endoleak resolution nor does it increase late endoleak rates. Irrespective of the anticoagulation status, early but not late endoleaks usually sealed spontaneously. Observing type II endoleaks appears safe in the absence of aneurysm enlargement.
authors.affiliation: Section of Vascular Surgery, Mayo Clinic Jacksonville, Florida 32224, USA.
authors.forename: Matthias
authors.initials: M
authors.lastname: Biebl
authors.forename: Albert G
authors.initials: AG
authors.lastname: Hakaim
authors.forename: W Andrew
authors.initials: WA
authors.lastname: Oldenburg
authors.forename: Josef
authors.initials: J
authors.lastname: Klocker
authors.forename: Louis L
authors.initials: LL
authors.lastname: Lau
authors.forename: Beate
authors.initials: B
authors.lastname: Neuhauser
authors.forename: J Mark
authors.initials: JM
authors.lastname: McKinney
authors.forename: Ricardo
authors.initials: R
authors.lastname: Paz-Fumagalli
mesh_terms: D000284:Administration, Oral; D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000401:mortality / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000379:methods*; D016022:Case-Control Studies; D016009:Chi-Square Distribution; D004305:Dose-Response Relationship, Drug; D004334:Drug Administration Schedule; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011182:Postoperative Care / Q000379:methods; D011183:Postoperative Complications / Q000517:prevention & control; D011336:Probability; D011475:Prosthesis Failure; D012042:Registries; D012189:Retrospective Studies; D018570:Risk Assessment; D012720:Severity of Illness Index; D015996:Survival Rate; D013997:Time Factors; D016896:Treatment Outcome; D014859:Warfarin / Q000627:therapeutic use*
chemical_list: D014859:Warfarin