title: Abdominal aortic aneurysm neck morphology: proposed classification system.
abstract: BACKGROUND
  While aneurysm neck length, angulation and width have all been previously assessed in endovascular abdominal aortic aneurysm repair (EVAR), aneurysm neck shape has not been considered.
  
  
  OBJECTIVE
  To analyse the influence of aneurysm neck morphology on outcome following EVAR.
  
  
  METHODS
  Aneurysm neck morphology in 70 patients undergoing EVAR from April 2001 to May 2004 was determined using pre-operative CT scans and graft plans. Necks were classified as flared, parallel, irregular, conical, barrel or hourglass. End-points were death,Type I endoleak and graft migration.
  
  
  RESULTS
  Forty-six per cent of necks were flared, 34% parallel, 9% irregular, 6% conical, 3% barrel and 3% hourglass. Mean follow-up was 20.2 months (range 4-35). There was one Type I endoleak and one graft migration. There were no aneurysm related deaths.
  
  
  CONCLUSIONS
  Assessment of aneurysm neck morphology should be part of the routine preoperative workup for EVAR. A classification system of AAA necks is suggested to facilitate this.
authors.affiliation: Dept of Vascular Surgery, Sir Charles Gairdner Hospital, Perth, Western Australia. comcdonnell@eircom.net
authors.forename: C O
authors.initials: CO
authors.lastname: McDonnell
authors.forename: M
authors.initials: M
authors.lastname: Halak
authors.forename: A
authors.initials: A
authors.lastname: Bartlett
authors.forename: S R
authors.initials: SR
authors.lastname: Baker
mesh_terms: D017544:Aortic Aneurysm, Abdominal / Q000145:classification* / Q000000981:diagnostic imaging / Q000601:surgery; D019917:Blood Vessel Prosthesis Implantation; D005500:Follow-Up Studies; D006801:Humans; D015607:Stents; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome