title: Differential effects of carotid artery stenting versus carotid endarterectomy on external carotid artery patency.
abstract: OBJECTIVE
  To determine the effect of stent coverage of the external carotid artery (ECA) after carotid artery stenting (CAS) compared to eversion endarterectomy of the ECA after carotid endarterectomy (CEA).
  
  
  METHODS
  The records of 101 CAS and 165 CEA procedures performed over 2 years were reviewed. Duplex velocities and history and physical examinations were taken prior to the procedure, at 1 month, and at 6-month intervals subsequently. CAS was performed by extending the stent across the internal carotid artery (ICA) lesion into the common carotid artery (CCA) thereby covering the ECA. CEA was performed with eversion endarterectomy of the ECA.
  
  
  RESULTS
  The mean peak systolic velocities (PSV) in the ICA pre-CAS and pre-CEA were 361 and 352 cm/s, respectively. In terms of CAS, there was a significant increase in ECA velocities versus baseline at 12 (p = 0.009), 18 (p = 0.00001), and 24 (p = 0.005) months. In the CEA group, there was a significant decrease in ECA velocities versus baseline at 1 (p = 0.01) and 6 (p = 0.004) months. There were 2 occluded ECAs in follow-up in the CAS group and none in the CEA group. No significant differences were noted when comparing preprocedural ICA or ECA velocities. However, at the 1-, 6-, and 12-month intervals, the ECA velocities in the CAS group were significantly higher than in the CEA group (p = 0.03, p = 0.001, and p = 0.0004, respectively). There were no neurological symptoms in any patients during the study period.
  
  
  CONCLUSIONS
  Although progressive stenosis of the ECA is noted during CAS, the ECA usually does not occlude. Furthermore, there are no associated neurological symptoms. Thus, apprehension for progressive ECA occlusion should not be a contraindication to CAS. In addition, concern for ECA coverage should not deter stent extension from the ICA to the CCA during CAS.
authors.affiliation: Division of Vascular Surgery, Department of Surgery, University of Pennsylvania Medical Center, Philadelphia, Pennsylvania 19104, USA. wooe@uphs.upenn.edu
authors.forename: Edward Y
authors.initials: EY
authors.lastname: Woo
authors.forename: Jagajan
authors.initials: J
authors.lastname: Karmacharya
authors.forename: Omaida C
authors.initials: OC
authors.lastname: Velazquez
authors.forename: Jeffrey P
authors.initials: JP
authors.lastname: Carpenter
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Skelly
authors.forename: Ronald M
authors.initials: RM
authors.lastname: Fairman
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D000792:Angiography / Q000379:methods; D017130:Angioplasty / Q000009:adverse effects; D001783:Blood Flow Velocity; D002342:Carotid Artery, External / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016893:Carotid Stenosis / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D016894:Endarterectomy, Carotid / Q000009:adverse effects; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D015607:Stents; D013997:Time Factors; D016896:Treatment Outcome; D018616:Ultrasonography, Doppler, Duplex; D014654:Vascular Patency