title: Effect of challenging neck anatomy on mid-term migration rates in AneuRx endografts.
abstract: OBJECTIVE
  To establish the effect of challenging neck anatomy on the mid- and long-term incidence of migration with the AneuRx bifurcated device in patients treated after Food and Drug Administration approval and to identify the predictive factors for device migration.
  
  
  METHODS
  Prospectively maintained databases at the University of North Carolina (UNC) and Washington University (WU) were used to identify 595 patients (UNC, n = 230; WU, n = 365) who underwent endovascular repair of an infrarenal abdominal aortic aneurysm with the AneuRx bifurcated stent graft. Those patients with at least 30 months of follow-up were identified and underwent further assessment of migration (UNC, n = 25; WU, n = 59) by use of multiplanar reconstructed computed tomographic scans.
  
  
  RESULTS
  Eighty-four patients with a mean follow-up time of 40.3 months (range, 30-55 months) were studied. Seventy percent of the patients (n = 59) met all inclusion criteria for neck anatomy (length, angle, diameter, and quality) as defined by the revised instructions for use guidelines and are referred to as those with favorable neck anatomy (FNA). The remaining 25 patients retrospectively fell outside of the revised instructions for use guidelines and are referred to as those with unfavorable neck anatomy (UFNA). Life-table analysis for FNA patients at 2 and 4 years revealed a migration rate of 0% and 6.1%, respectively. For UFNA patients, it was 24.0% and 42.1% at 2 and 4 years, respectively (P < .0001). The overall (FNA and UFNA) migration rate was 7.1% and 17.1% at 2 and 4 years, respectively. Overall, late graft-related complications occurred in 38% of patients (FNA, 27%; UFNA, 64%; P = .003; relative risk, 1.7). There was no incidence of late rupture or open conversion. The relative risk of migration for UFNA patients was 2.5 compared with FNA patients (P = .0003). A larger neck angle and a longer initial graft to renal artery distance were predictors of migration, whereas shorter neck length approached but did not reach statistical significance.
  
  
  CONCLUSIONS
  Patients who have unfavorable aneurysm neck anatomy experience significantly higher migration, device-related complication, and secondary intervention rates. However, there was no incidence of open conversion, rupture, or abdominal aortic aneurysm-related death, thereby supporting the AneuRx device as a feasible alternative to open repair even in patients with challenging neck characteristics. Enhanced surveillance should be used in these high-risk patients.
authors.affiliation: Department of Surgery, Division of Vascular Surgery, University of North Carolina, Chapel Hill, NC 27599, USA. j_fulton@med.unc.edu
authors.forename: Joseph J
authors.initials: JJ
authors.lastname: Fulton
authors.forename: Mark A
authors.initials: MA
authors.lastname: Farber
authors.forename: Luis A
authors.initials: LA
authors.lastname: Sanchez
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Godshall
authors.forename: William A
authors.initials: WA
authors.lastname: Marston
authors.forename: Robert
authors.initials: R
authors.lastname: Mendes
authors.forename: Brian G
authors.initials: BG
authors.lastname: Rubin
authors.forename: Gregorio A
authors.initials: GA
authors.lastname: Sicard
authors.forename: Blair A
authors.initials: BA
authors.lastname: Keagy
mesh_terms: D000368:Aged; D001012:Aorta, Abdominal / Q000000981:diagnostic imaging* / Q000601:surgery; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000601:surgery*; D001807:Blood Vessel Prosthesis; D019917:Blood Vessel Prosthesis Implantation / Q000295:instrumentation*; D005260:Female; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000453:epidemiology / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008297:Male; D011379:Prognosis; D011446:Prospective Studies; D011475:Prosthesis Failure; D013997:Time Factors; D014057:Tomography, X-Ray Computed