title: Influence of different self-expanding stent-graft types on remodeling of the aortic neck after endovascular aneurysm repair.
abstract: OBJECTIVE
  To evaluate aortic neck changes, specifically aortic neck dilatation, over a 10-year period in patients undergoing endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm.
  
  
  METHODS
  All patients who underwent elective EVAR at our institution from 1998 through 2007 were analyzed retrospectively. Among these, 103 patients (96 men; mean age 71 years, range 35-84) who received the 3 most frequently implanted self-expanding stent-grafts (35 Talent, 39 Excluder, and 29 Zenith) and had a minimum 3-month imaging follow-up at our department were selected for this study. All diameters were measured perpendicular to the centerline of flow on computed tomography; baseline data were derived from the first postoperative scan. Stent-graft migration was measured from the lowermost renal artery to the first strut of the stent-graft. Based on intra- and interobserver error measurements, a minimum change of 2 mm defined aortic neck dilatation.
  
  
  RESULTS
  During a mean follow-up of 39.4 months (range 3-108.8), infrarenal aortic neck dilatation (>2 mm) was found in 10 patients (28.6%, 95% CI 14.6-46.3) in the Talent group, 4 (10.3%, 95% CI 2.9-24.2) in the Excluder group, and 9 (31.0%, 95% CI 15.3-50.8) in the Zenith group (p=0.299). In 7 (31%) of the 23 patients with neck dilatation, additional therapy was necessary. Suprarenal changes were found in 6 patients (17.1%, 95% CI 6.6-33.6), 8 patients (20.5%, 95% CI 9.3-36.5), and 5 patients (17.2%, 95% CI 5.8-35.8), respectively (p=0.218). Stent-graft migration >2 mm was seen in 2 (1.9%) of the 103 patients in follow-up. The overall endoleak rates were 37.1% for Talent, 30.8% for Excluder, and 37.9% for Zenith (p>0.05). Two patients were converted to open repair owing to Talent stent-graft migration and persistent type I leak (Zenith). The overall reintervention rate was 13.6% (13/103).
  
  
  CONCLUSIONS
  Only a small number of the patients treated with self-expanding stent-grafts show notable infrarenal aortic neck dilatation, which does not appear to be related to the stent-graft model. Almost all cases of aortic neck dilatation exceeded the percentage of oversizing; less than a third of patients with aortic neck dilatation required therapy.
authors.affiliation: Department of Thoracic and Vascular Surgery, University of Ulm, Germany. alexander.oberhuber@uniklinik-ulm.de
authors.forename: Alexander
authors.initials: A
authors.lastname: Oberhuber
authors.forename: Alexander
authors.initials: A
authors.lastname: Schwarz
authors.forename: Martin H
authors.initials: MH
authors.lastname: Hoffmann
authors.forename: Oliver
authors.initials: O
authors.lastname: Klass
authors.forename: Karl-Heinz
authors.initials: KH
authors.lastname: Orend
authors.forename: Bernd
authors.initials: B
authors.lastname: Mühling
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001027:Aortography / Q000379:methods; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects / Q000295:instrumentation*; D004108:Dilatation, Pathologic; D017558:Elective Surgical Procedures; D057867:Endoleak / Q000209:etiology; D057510:Endovascular Procedures / Q000009:adverse effects / Q000295:instrumentation*; D005260:Female; D005548:Foreign-Body Migration / Q000209:etiology; D005858:Germany; D006801:Humans; D008297:Male; D008875:Middle Aged; D015588:Observer Variation; D011237:Predictive Value of Tests; D011474:Prosthesis Design; D012086:Reoperation; D015203:Reproducibility of Results; D012189:Retrospective Studies; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome