title: The effect of warfarin therapy on endoleak development after endovascular aneurysm repair (EVAR) of the abdominal aorta.
abstract: OBJECTIVE
  The presence of an endoleak after endovascular abdominal aortic aneurysm (AAA) repair (EVAR) may predispose to sac expansion and potential sac rupture. The incidence of endoleak after AAA repair can be as high as 20% to 30%. We investigated whether warfarin anticoagulation was an independent risk factor for endoleak after EVAR for AAA.
  
  
  METHODS
  All AAA patients who underwent elective EVAR were prospectively followed-up. Data for demographics, clinical comorbidities, outcomes, EVAR devices, and anticoagulation methods were recorded. All patients underwent routine follow-up at 1, 6, and 12 months and annually thereafter. Computed tomography angiography (CTA) with 3-dimensional (3D) volumetric analysis was also completed.
  
  
  RESULTS
  During a 7-year period, 127 consecutive patients with infrarenal AAAs who underwent EVAR were monitored for a mean of 2.14 years. The average age at the time of EVAR was 73.8 years. Warfarin therapy alone was administered to 24 patients, and anticoagulation with antiplatelet therapy alone was administered to 103. During the study period, 38 (29.9%) endoleaks were documented. The overall endoleak rate was 13 of 24 in the warfarin group and 25 of 103 in the antiplatelet group (P = .004). CTA 3D volumetric aneurysm sac analysis showed an increase of 16.09% in the warfarin study group and a reduction of 9.71% in the antiplatelet group (P = .04).
  
  
  CONCLUSIONS
  Anticoagulation with warfarin appears to be linked to an increased risk for the development of endoleak after EVAR, specifically type II. Volumetric analysis showed warfarin therapy also contributed to persistent aneurysm sac expansion. These data suggest that patients who require warfarin anticoagulation for other indications should be advised that they might be at an increased risk for the development of endoleaks, subsequent secondary interventions, persistent sac expansion, and possible delayed sac rupture.
authors.affiliation: Department of Surgery, Division of Vascular Surgery, School of Medicine and Public Health, University of Wisconsin-Madison, Madison, Wis 53792-3236, USA.
authors.forename: Joseph L
authors.initials: JL
authors.lastname: Bobadilla
authors.forename: John R
authors.initials: JR
authors.lastname: Hoch
authors.forename: Glen E
authors.initials: GE
authors.lastname: Leverson
authors.forename: Girma
authors.initials: G
authors.lastname: Tefera
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000925:Anticoagulants / Q000009:adverse effects*; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D017558:Elective Surgical Procedures; D005260:Female; D006801:Humans; D008297:Male; D011474:Prosthesis Design; D011475:Prosthesis Failure; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D013997:Time Factors; D036542:Tomography, Spiral Computed; D016896:Treatment Outcome; D014859:Warfarin / Q000009:adverse effects*; D014922:Wisconsin
chemical_list: D000925:Anticoagulants; D014859:Warfarin