Development of Subclavian Artery Steal Syndrome after Endoluminal Thoracic Aortic Arch Aneurysm Repair
John Chen, DO and Yong G Peng, MD, PhD
Department of Anesthesiology, University of Florida, Gainesville, Florida
Subclavian steal syndrome results from an obstruction or stenosis of the
subclavian artery. with retrograde blood flow of the ipsilateral vertebral
artery, causing neurologic symptoms from cerebral ischemia. The most common
cause of subclavian steal syndrome is atherosclerotic vascular disease.
Endovascular repair of thoracic aortic aneurysms can potentially cause an
iatrogenic subclavian artery steal. The majority of those patients do not
develop neurologic symptoms. On the other hand, for those patients who
develop dizziness, ataxia, vertigo, blurry vision, confusion, headache,
syncope, or transient blindness, these neurologic symptoms can be
debilitating.
A 61 year old man with a thoracic aortic arch aneurysm underwent aorta to
innominate and left carotid artery bypass followed by endoluminal aortic
stent placement. After the procedure, he developed transient blindness,
memory loss, and mild left arm pain. Further workup revealed that the
patient's blood pressure in the left arm was significantly lower than that
in the right. CT Angiogram of head and neck revealed posterior circulation
ischemia. The left vertebral artery anastomosed not with the basilar artery,
but the left posterior inferior cerebellar artery. Because of the symptoms
and insufficient collateral flow, the patient underwent a left carotid to
subclavian artery bypass with a Gore-Tex graft. The patient’s symptoms
slowly improved and he was discharged home on post-operative day 9. Upon
follow-up on post-operative day 19, the patient continues to improve with
decreasing visual changes and confusion.
Thoracic aortic arch aneurysm repairs with endoluminal stents usually
occlude the left subclavian artery. Patients may not develop neurologic
symptoms if they have an intact Circle of Willis and can provide adequate
collateral blood flow to the subclavian artery. However, if collateral flow
is not sufficient, steal from the vertebral artery can cause cerebral
ischemia with the development of neurologic symptoms, resulting in
subclavian steal syndrome. It may be necessary to demonstrate sufficient
collateral circulation to the subclavian artery and/or the vertebral artery
from the Circle of Willis prior to surgery either by CT angiogram or
arteriogram. If collateral flow is not adequate, then prophylactic carotid
to subclavian artery bypass may be performed at the same time or prior to
endoluminal stent placement.
