title: External carotid dissection and external carotid proatlantal intersegmental artery with subclavian steal prompting external carotid and subclavian artery stenting.
abstract: OBJECTIVE
  The authors describe a case of a proatlantal intersegmental artery seen in the setting of external carotid artery dissection and subclavian steal due to proximal subclavian artery stenosis.
  
  
  METHODS
  An 83-year-old woman presented with left homonymous hemianopsia and a right posterior cerebral artery distribution stroke. She was found to have severe left subclavian artery stenosis proximal to the vertebral artery (VA) and an occluded contralateral VA. Doppler ultrasonography and angiography both showed a dissection of the proximal left external carotid artery. Left common carotid artery angiography also demonstrated a connection between the external carotid and vertebral arteries at the C1 level with anterograde flow into the vertebrobasilar system and retrograde flow toward the vertebral origin, consistent with subclavian steal.
  
  
  RESULTS
  The patient underwent successful stenting of the subclavian and external carotid arteries with resolution of anterograde flow in the left VA.
  
  
  CONCLUSIONS
  This case represents an interesting presentation of both subclavian steal and an external carotid artery to VA anastomosis. Also, the presence of a dissection of the external carotid artery represents a rare finding.
authors: Department of Neurosurgery and Toshiba Stroke and Vascular Research Center, Buffalo, NY; Department of Neurosurgery, Gates Vascular Institute, Kaleida Health, Buffalo, NY.
authors: Adib A
authors: AA
authors: Abla
authors: Peter
authors: P
authors: Kan
authors: Shady
authors: S
authors: Jahshan
authors: Travis M
authors: TM
authors: Dumont
authors: Elad I
authors: EI
authors: Levy
authors: Adnan H
authors: AH
authors: Siddiqui
mesh_terms: D000368:Aged; D002342:Carotid Artery, External / Q000000981:diagnostic imaging / Q000601:surgery*; D020215:Carotid Artery, Internal, Dissection / Q000150:complications* / Q000000981:diagnostic imaging / Q000601:surgery*; D005260:Female; D006801:Humans; D011859:Radiography; D015607:Stents; D013348:Subclavian Artery / Q000000981:diagnostic imaging / Q000601:surgery*; D013349:Subclavian Steal Syndrome / Q000000981:diagnostic imaging / Q000209:etiology* / Q000601:surgery*; D016896:Treatment Outcome
keywords: External carotid dissection; proatlantal intersegmental artery; stenting; subclavian steal; subclavian stenosis