title: Aortic morphometry at endograft position as assessed by 3D image analysis affects risk of type I endoleak formation after TEVAR.
abstract: OBJECTIVE
  The purpose of this study was to identify morphologic factors affecting type I endoleak formation and bird-beak configuration after thoracic endovascular aortic repair (TEVAR).
  
  
  METHODS
  Computed tomography (CT) data of 57 patients (40 males; median age, 66 years) undergoing TEVAR for thoracic aortic aneurysm (34 TAA, 19 TAAA) or penetrating aortic ulcer (n = 4) between 2001 and 2010 were retrospectively reviewed. In 28 patients, the Gore TAG® stent-graft was used, followed by the Medtronic Valiant® in 16 cases, the Medtronic Talent® in 8, and the Cook Zenith® in 5 cases. Proximal landing zone (PLZ) was in zone 1 in 13, zone 2 in 13, zone 3 in 23, and zone 4 in 8 patients. In 14 patients (25%), the procedure was urgent or emergent. In each case, pre- and postoperative CT angiography was analyzed using a dedicated image processing workstation and complimentary in-house developed software based on a 3D cylindrical intensity model to calculate aortic arch angulation and conicity of the landing zones (LZ).
  
  
  RESULTS
  Primary type Ia endoleak rate was 12% (7/57) and subsequent re-intervention rate was 86% (6/7). Left subclavian artery (LSA) coverage (p = 0.036) and conicity of the PLZ (5.9 vs. 2.6 mm; p = 0.016) were significantly associated with an increased type Ia endoleak rate. Bird-beak configuration was observed in 16 patients (28%) and was associated with a smaller radius of the aortic arch curvature (42 vs. 65 mm; p = 0.049). Type Ia endoleak was not associated with a bird-beak configuration (p = 0.388). Primary type Ib endoleak rate was 7% (4/57) and subsequent re-intervention rate was 100%. Conicity of the distal LZ was associated with an increased type Ib endoleak rate (8.3 vs. 2.6 mm; p = 0.038).
  
  
  CONCLUSIONS
  CT-based 3D aortic morphometry helps to identify risk factors of type I endoleak formation and bird-beak configuration during TEVAR. These factors were LSA coverage and conicity within the landing zones for type I endoleak formation and steep aortic angulation for bird-beak configuration.
authors.affiliation: Department of Vascular and Endovascular Surgery, Heidelberg University Hospital, Im Neuenheimer Feld 110, 69120, Heidelberg, Germany, drosos.kotelis@med.uni-heidelberg.de.
authors.forename: Drosos
authors.initials: D
authors.lastname: Kotelis
authors.forename: Carolin
authors.initials: C
authors.lastname: Brenke
authors.forename: Stefan
authors.initials: S
authors.lastname: Wörz
authors.forename: Fabian
authors.initials: F
authors.lastname: Rengier
authors.forename: Karl
authors.initials: K
authors.lastname: Rohr
authors.forename: Hans-Ulrich
authors.initials: HU
authors.lastname: Kauczor
authors.forename: Dittmar
authors.initials: D
authors.lastname: Böckler
authors.forename: Hendrik
authors.initials: H
authors.lastname: von Tengg-Kobligk
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001013:Aorta, Thoracic / Q000473:pathology*; D017545:Aortic Aneurysm, Thoracic / Q000473:pathology* / Q000601:surgery*; D057867:Endoleak / Q000453:epidemiology* / Q000473:pathology*; D057510:Endovascular Procedures; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors