title: C-arm CT--an adjunct to DSA for endoleak classification in patients with endovascular repair of abdominal aortic aneurysms.
abstract: OBJECTIVE
  To assess the benefit of C-arm CT for classification and procedural guidance during interventional therapy of endoleaks (EL) after endovascular repair (EVAR) of abdominal aortic aneurysms (AAA).
  
  
  METHODS
  12 patients with EL diagnosed with CT but undetermined EL classification (ELC) underwent DSA and transarterial contrast-enhanced C-arm CT. ELC (based on DSA, C-arm CT and CT) assessed during the angiographic procedure served as the standard of reference (SOR). Subsequently, ELC was assessed by a blinded second reader based on DSA or C-arm CT and compared to the SOR. In the case of an interventional procedure (n = 6), the added value of C-arm CT for procedure guidance was assessed retrospectively (1: essential, 2: helpful, 3: additional information without impact, 4: no additional information).
  
  
  RESULTS
  The blinded reader classified 9/12 EL using DSA alone and 11/12 EL using C-arm CT alone. In one patient, the temporal resolution provided by DSA was essential to establish the diagnosis. In 6 patients, a type 2 EL without need for therapy was diagnosed. The remaining 6 patients showed EL that were treated immediately (type 1 EL, n = 4: 3 stent graft extensions and one angioplasty; type 2 EL, n = 1: translumbar embolization; type 3 EL, n = 1: sealing of a fabric tear). The information provided by C-arm CT was assessed to be essential in three patients and helpful in two.
  
  
  CONCLUSIONS
  C-arm CT is an ideal adjunct to DSA. In our pilot study, it helped to localize and classify endoleaks more reliably than DSA alone.
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University School of Medicine Hannover.
authors.forename: F K
authors.initials: FK
authors.lastname: Wacker
authors.affiliation: Russell H. Morgan Department of Radiology and Radiological Science, Division of Vascular and Interventional Radiology, Johns Hopkins University School of Medicine, Baltimore.
authors.forename: S
authors.initials: S
authors.lastname: Valdeig
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University School of Medicine Hannover.
authors.forename: H J
authors.initials: HJ
authors.lastname: Raatschen
authors.affiliation: Institute of Diagnostic and Interventional Radiology, University School of Medicine Hannover.
authors.forename: B C
authors.initials: BC
authors.lastname: Meyer
mesh_terms: D015901:Angiography, Digital Subtraction / Q000379:methods*; D017544:Aortic Aneurysm, Abdominal / Q000150:complications / Q000000981:diagnostic imaging* / Q000601:surgery*; D057867:Endoleak / Q000000981:diagnostic imaging* / Q000209:etiology*; D057510:Endovascular Procedures / Q000009:adverse effects*; D006801:Humans; D064847:Multimodal Imaging / Q000379:methods; D015588:Observer Variation; D011856:Radiographic Image Enhancement / Q000379:methods; D011860:Radiography, Abdominal / Q000379:methods; D012189:Retrospective Studies; D025321:Surgery, Computer-Assisted / Q000379:methods; D014057:Tomography, X-Ray Computed / Q000379:methods*; D016896:Treatment Outcome