title: Morphometric analysis of anatomic variables affecting endovascular stent design in patients undergoing elective and emergency repair of endovascular abdominal aortic aneurysm.
abstract: BACKGROUND
  Our objective was to identify morphologic trends in elective and emergency endovascular aneurysm repair (EVAR). This work will inform hospitals with endovascular programs about the diameters and lengths of endostents that should be available to efficiently care for patients with these conditions.
  
  
  METHODS
  We performed a retrospective review of patients undergoing elective (n = 127) and emergency (n = 17) EVAR. Using computed tomography and 3-dimensional reconstructions, we evaluated the following: diameters of the aneurysm (D3), the aorta at the superior mesenteric (D1) and renal (D2a,b,c; 3 levels) levels, the iliac arteries (D5a,b; right and left) and the aortic bifurcation (D4); lengths from the lowest renal artery to the distal aspect of the aortic neck (H1), to the aortic bifurcation (H3), to the right and left iliac bifurcations (H4a,b); and angles of the origin of the common iliac arteries on the transverse plane (A1). We used descriptive statistics of trends within groups and independent sample t tests.
  
  
  RESULTS
  In elective and emergency aneurysm repair, D2max (26, standard deviation [SD] 3, mm v. 30.7 [SD 3] mm), D5a (16 [SD 4.7] mm v. 19.3 [SD 5] mm), D5b (15.3 [SD 4] mm v. 18.1 [SD 3.6] mm), H1 (25.6 [SD 8.6] mm v. 18 [SD 2] mm), H4a (173 [SD 22] mm v. 189.5 [SD 22] mm) and H4b (174 [SD 25] mm v. 190 [SD 14] mm) were significantly different between the 2 groups (p = 0.001, p = 0.006, p = 0.007, p < 0.001, p = 0.05 and p = 0.01, respectively). H3 (118 [SD 17] mm v. 121.5 [SD 13.5] mm) was not significantly different (p = 0.40). In elective patients, A1 identified the right common iliac more frequently anterior relative to the left common iliac (mean 23 degrees , SD 16 degrees).
  
  
  CONCLUSIONS
  Significant anatomic differences between elective and emergency patients will require hospitals to stock separate endovascular devices to treat abdominal aortic aneurysms in both groups.
authors.affiliation: The Division of Vascular Surgery, St. Michael's Hospital, University of Toronto, Toronto, Ont.
authors.forename: Michael
authors.initials: M
authors.lastname: Kilian
authors.forename: Wilfred
authors.initials: W
authors.lastname: Dang
authors.forename: Claudio S
authors.initials: CS
authors.lastname: Cinà
mesh_terms: D001012:Aorta, Abdominal / Q000000981:diagnostic imaging / Q000473:pathology*; D017544:Aortic Aneurysm, Abdominal / Q000473:pathology* / Q000601:surgery*; D019917:Blood Vessel Prosthesis Implantation; D017558:Elective Surgical Procedures; D004638:Emergency Treatment; D006801:Humans; D007083:Iliac Artery / Q000000981:diagnostic imaging / Q000473:pathology*; D011474:Prosthesis Design; D017755:Prosthesis Fitting; D012189:Retrospective Studies; D015607:Stents; D014057:Tomography, X-Ray Computed