title: Predictors of difficult carotid stenting as determined by aortic arch angiography.
abstract: OBJECTIVE
  Although different aortic arch classifications exist to help determine carotid artery stenting (CAS) difficulty, they are not validated. We compared quantitative angiographic characteristics of aortic arch between easy and difficult CAS.
  
  
  METHODS
  We defined difficult procedures as requiring the longest fluoroscopy time (FT) (90th percentile) and easy procedures as the shortest FT (10th percentile) from our CAS database. We excluded patients undergoing additional procedures, intraprocedural complications or those with difficult vascular access.
  
  
  RESULTS
  We analyzed 24 patients with difficult CAS (median fluoroscopy time of 58 minutes) and 24 with easy CAS (median fluoroscopy time of 19 minutes). The two groups were similar with respect to demographics, comorbidities and clinical presentation at the time of CAS. Patients with difficult procedures had a longer distance from the origin of treated artery to the beginning of the descending aorta (D1; 50 +/- 17 mm vs. 40 +/- 16 mm; p = 0.04), severe tortuosity (T) of the common carotid and internal carotid vessels (T; 50.0% vs. 16.7%; p = 0.03) and a trend in the presence of a Type 3 arch (33.3% vs. 25.0%; p = 0.18) and angulated takeoff (20.8% vs. 4.3%; p = 0.19). There was no difference in the severity of stenosis or index lesion calcification, ulceration and eccentricity between the two groups. On multivariate analysis, independent predictors of procedural difficulty were D1 (odds ratio 1.04 per mm; 95% CI, 1.01-1.09; p = 0.04), and T (odds ratio 4.77; 95% CI 1.3-42.9; p = 0.03).
  
  
  CONCLUSIONS
  Distance from the origin of the treated artery to the beginning of the D1 and target vessel T determine prolonged fluoroscopy time during CAS.
authors.affiliation: Cleveland Clinic, F25, 9500 Euclid Avenue, Cleveland, OH, 44195, USA.
authors.forename: Surabhi
authors.initials: S
authors.lastname: Madhwal
authors.forename: Vivek
authors.initials: V
authors.lastname: Rajagopal
authors.forename: Deepak L
authors.initials: DL
authors.lastname: Bhatt
authors.forename: Christopher T
authors.initials: CT
authors.lastname: Bajzer
authors.forename: Patrick
authors.initials: P
authors.lastname: Whitlow
authors.forename: Samir R
authors.initials: SR
authors.lastname: Kapadia
mesh_terms: D000368:Aged; D000792:Angiography; D001013:Aorta, Thoracic / Q000033:anatomy & histology* / Q000000981:diagnostic imaging*; D019917:Blood Vessel Prosthesis Implantation; D002339:Carotid Arteries / Q000601:surgery*; D005260:Female; D005471:Fluoroscopy; D006801:Humans; D008297:Male; D008875:Middle Aged; D011379:Prognosis; D015607:Stents; D013997:Time Factors