title: Midterm results of endovascular aneurysm repair using the Endurant stent-graft according to the instructions for use vs. off-label conditions.
abstract: OBJECTIVE
  To compare the midterm results in patients treated with the Endurant stent-graft according to device-specific instructions for use (IFU) vs. those treated in an off-label (OL) situation.
  
  
  METHODS
  Between November 2007 and March 2010, 177 patients (161 men; mean age 73.7 years) with abdominal aortic aneurysm were treated with the Endurant stent-graft at 2 European centers. Patients operated on according to the IFU (121, 68.4%) were compared with those who underwent endovascular aneurysm repair in OL circumstances (56, 31.6%) to evaluate estimated 5-year survival, freedom from any device-related reinterventions, freedom from graft thrombosis, and freedom from type I endoleak. Univariate and multivariate analyses were performed to identify independent predictors of poor outcomes in the OL group.
  
  
  RESULTS
  Mean follow-up was 31.2 months (range 1-65). At 5 years, there were no differences in terms of survival (67.9% IFU vs. 54.1% OL, p=0.3), freedom from any device-related reintervention (91.2% IFU vs. 92.4% OL, p=0.8), or freedom from graft thrombosis (97.5% IFU vs. 92.7% OL, p=0.3). Estimated 5-year freedom from type I endoleak was significantly better in the IFU group than in OL (100% vs. 96.2%, respectively; p=0.03). In the OL group, multivariate analysis showed that female sex and coronary artery disease were independent predictors of poor survival.
  
  
  CONCLUSIONS
  Off-label use of the Endurant stent-graft was associated with a greater but acceptable risk of type I endoleak. Otherwise, there was no difference between the IFU and off-label groups as regards survival, graft thrombosis, or reintervention.
authors.affiliation: 1 Department of Surgery, Vascular and Endovascular Surgery Unit, San Giovanni di Dio Hospital, Florence, Italy.
authors.forename: Nicola
authors.initials: N
authors.lastname: Troisi
authors.forename: Giovanni
authors.initials: G
authors.lastname: Torsello
authors.forename: Kristin
authors.initials: K
authors.lastname: Weiss
authors.forename: Konstantinos P
authors.initials: KP
authors.lastname: Donas
authors.forename: Stefano
authors.initials: S
authors.lastname: Michelagnoli
authors.forename: Martin
authors.initials: M
authors.lastname: Austermann
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000175:diagnosis / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation* / Q000401:mortality; D005260:Female; D005858:Germany; D006801:Humans; D007558:Italy; D053208:Kaplan-Meier Estimate; D008297:Male; D015999:Multivariate Analysis; D018579:Patient Selection; D011183:Postoperative Complications / Q000401:mortality / Q000628:therapy; D011356:Product Labeling; D016016:Proportional Hazards Models; D011474:Prosthesis Design; D018570:Risk Assessment; D012307:Risk Factors; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome
keywords: abdominal aortic aneurysm; aortic neck; endograft; endovascular aneurysm repair; graft thrombosis; instructions for use; off-label use; reinterventions; stent-graft; type I endoleak