title: Failure of aneurysm sac shrinkage after endovascular repair; the effect of mural calcification.
abstract: OBJECTIVE
  To evaluate the effect of abdominal aortic aneurysm wall calcification on subsequent sac shrinkage after endovascular repair.
  
  
  METHODS
  Seventy-three patients underwent endovascular aneurysm repair. The degree of sac wall calcification on pre-procedural computed tomography (CT) examination was graded from 1 to 4 according to the degree of circumferential involvement. On follow-up CT imaging, the maximum transverse diameter (MTD) of the sac was recorded, as well as the presence or absence of endoleak. In those patients with a non-shrinking aneurysm, but no CT evidence of endoleak, contrast-enhanced ultrasound (USS) was performed. Any patient with an endoleak, however diagnosed, was excluded from the study. Kruskal-Wallis and Spearman's rank correlation coefficient testing was applied to compare the degree of calcification and change in MTD.
  
  
  RESULTS
  Sixty-three pre-procedural CT images were available for calcification grading. Six of this group had endoleaks resulting in 57 sets of data being available for the study. A reduction in MTD occurred in 68.25% of these patients by 1 year post-procedure. Our figures show aortic calcification is inversely associated with MTD reduction at 6 months (p = 0.01), 1 year (p = 0.05) and 2 years (p = 0.05).
  
  
  CONCLUSIONS
  This study indicates that the degree of aortic wall calcification is significant in predicting MTD reduction post-endovascular repair. The possible mechanisms and implications of this are discussed.
authors.affiliation: Department of Radiology, Royal Victoria Hospital, Belfast, UK. mark.love@royalhospitals.n-i.nhs.uk
authors.forename: M
authors.initials: M
authors.lastname: Love
authors.forename: A
authors.initials: A
authors.lastname: Wray
authors.forename: M
authors.initials: M
authors.lastname: Worthington
authors.forename: P
authors.initials: P
authors.lastname: Ellis
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D001012:Aorta, Abdominal / Q000473:pathology; D017544:Aortic Aneurysm, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D001027:Aortography; D019917:Blood Vessel Prosthesis Implantation; D002114:Calcinosis / Q000150:complications* / Q000000981:diagnostic imaging; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D011475:Prosthesis Failure; D012189:Retrospective Studies; D018709:Statistics, Nonparametric; D015607:Stents; D013997:Time Factors; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D018084:Ultrasonography, Interventional