title: Stent-graft migration following endovascular repair of aneurysms with large proximal necks: anatomical risk factors and long-term sequelae.
abstract: OBJECTIVE
  To evaluate the outcome of aortic endografts deployed in large infrarenal necks and to identify any association of preoperative aneurysm characteristics and postoperative morphological changes with the incidence of neck dilatation and device migration in this patient subset.
  
  
  METHODS
  The records of 47 patients (41 men; mean age 74, range 55-84) with large aortic neck diameters treated with Talent stent-grafts from 1998 to 2001 were reviewed. Patients with anatomical criteria that precluded aneurysm exclusion with currently available devices were preferentially selected. Mean baseline aneurysm morphology included 27.6-mm (range 18-33.4) suprarenal and 28.1-mm (range 24-34) infrarenal neck diameters; the infrarenal neck length was 26 +/- 16 mm with angulation of 37 degrees +/- 18 degrees. Computed tomographic (CT) angiograms up to 3 years were analyzed using specialized interactive software; migration was defined as >1-cm change in the distance from the lower renal artery to the top of the device. Pre- and postoperative morphological characteristics of the aneurysm were compared between patients with and without migration.
  
  
  RESULTS
  Of the 45 patients successfully treated, 40 had complete CT data for analysis. During a mean 17-month follow-up, 7 (17.5%) of the 40 devices exhibited distal migration. Six patients required secondary procedures; 5 were in the migration cohort. No preoperative anatomical characteristic or degree of neck dilatation over time was predictive of stent-graft migration. Aneurysm sac regression was significant at 1 (-0.09 +/- 4.90 mm) and 2 (-1.48 +/- 2.56 mm) years in endografts without migration (p<0.001). Distal endograft migration >1 cm predicted the need for secondary interventions (p<0.001), with 83% sensitivity and 94% specificity.
  
  
  CONCLUSIONS
  Endovascular repair is successful in patients with large infrarenal necks and complex neck morphology. Changes in aneurysm remodeling over time were similar to reported observations in patients with more favorable neck criteria. Although no anatomical factor associated with migration could be identified from this analysis, distal displacement >1 cm correlated with the need for a secondary intervention.
authors.affiliation: Department of Surgery, Harbor-UCLA Medical Center, Torrance, California 90509, USA. jtlee@humc.edu
authors.forename: James T
authors.initials: JT
authors.lastname: Lee
authors.forename: Jason
authors.initials: J
authors.lastname: Lee
authors.forename: Ihab
authors.initials: I
authors.lastname: Aziz
authors.forename: Carlos E
authors.initials: CE
authors.lastname: Donayre
authors.forename: Irwin
authors.initials: I
authors.lastname: Walot
authors.forename: George E
authors.initials: GE
authors.lastname: Kopchok
authors.forename: Mauricio
authors.initials: M
authors.lastname: Heilbron
authors.forename: Maurice
authors.initials: M
authors.lastname: Lippmann
authors.forename: Rodney A
authors.initials: RA
authors.lastname: White
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation / Q000009:adverse effects*; D004108:Dilatation, Pathologic / Q000000981:diagnostic imaging / Q000209:etiology / Q000503:physiopathology; D005260:Female; D005500:Follow-Up Studies; D005548:Foreign-Body Migration / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D015607:Stents / Q000009:adverse effects*; D013997:Time Factors; D014057:Tomography, X-Ray Computed