Vascular—Carotid Stenosis
Concept
Usually described as extracranial cerebrovascular disease.
Must have appropriate indications for surgery here! Be sure to differentiate from the rare “posterior” ischemia that comes from the basovertebral system.
Way Question May be Asked?
“A 53 y/o female seen in the ED for a TIA which resolved in the next several hours is later referred to your office for evaluation for a carotid endarterectomy. She has a bruit on the left side.”
How to Answer?
History should focus on risk factors:
HTN DM
Elevated cholesterol Vascular disease elsewhere
History of TIA (ocular or hemispheric symptoms) History of stroke
History should also focus on symptoms being sure to r/o other possibilities:
Recent MI A. fib
Ataxia, gait disturbances, bilateral lower extremity weakness →basovertebral ischemia
Intracranial pathology
Physical Exam
Look for signs of vascular disease Neuro exam
Bruits
BP gradient between the two arms
Remember non-invasive testing (these pts have vascular disease everywhere):
Arrhythmias on EKG
Carotid duplex scanning—plaque characteristics, flow velocities, % stenosis
CT or MRI of brain in symptomatic pts
MRA if available (if not, angiogram to include aortic arch and proximal common carotid artery)
Indications for Surgery
Symptomatic pts with ≥ 70% stenosis
Symptomatic pts with < 70% and ulcerated plaque or failure of medical therapy
Asymptomatic pts with ≥ 80% stenosis Crescendo TIAs
Nonoperative Therapy
Asymptomatic pt is treated with aspirin or Plavix Q 6 month follow-up with repeat non-invasive testing
Operative Approach
Position pt supine with head elevated and turn to oppo- site side
Gentle prepping of neck (don’t want to injury fragile plaque)
Oblique incision along anterior border of SCM Dissect common carotid along medial border to avoid
vagus nerve injury
Expose common carotid, internal carotid, and external carotid with minimal manipulation
Divide facial vein as usually enters IJ at level of bifurcation
Apply clamps/tourniquets in disease free areas Anticoagulate pt with Heparin 100U/kg
Select shunt (safest on the oral exam to shunt all pts and perform surgery under general anesthesia)
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Arteriotomy begins on proximal CCA and extends onto ICA (above and below gross intimal disease) Make sure to carefully back-bleed shunt free of
air/debris
Dissect plaque free of arterial wall with blunt dissector Make sure there is no loose flap or tack down shelf (6-O prolene double arm, vertically placed so as not to constrict lumen of ICA, knots on outside of vessel)
Close vessel with vein patch or Hemashield patch Flush all vessels before closure and releasing ICA
clamp
Open external first again to flush air/debris away from ICA distribution
Reversal of heparin with protamine and use of drains is surgeon dependent
Common Curveballs
Carotid artery will be completely occluded at time of surgery
Pt will have post-op stroke or stroke after you order an angiogram
Pt will have 78% stenosis and be asymptomatic Pt will have 68% stenosis and be symptomatic Pt will have ulcerated plaque
Consulted to see a pt with carotid occlusion
Consulted to see a pt with recent stroke (check CT, if no stroke, heparin and CEA in 1 week, if stroke, CEA in 2 months)
Restenosis after CEA
Post-op: MI, neurologic deficit in recovery room, headache, bradycardia in recovery room
Pt will have acute stroke in your follow-up of an asymp- tomatic lesion (don’t rush to operate →get CT of head, treat with TPA if in first 3 h, otherwise ASA, physical therapy, and CEA in 6 weeks)
Pt will have expanding hematoma in neck post-op Disease/plaque will continue up into base of skull Won’t be an appropriate vein to harvest to use as a
patch Post-op MI
Post-op hypertension/hypotension (NTG/nitroprusside or volume replacement/dopamine respectively) Post-op nerve injury
Management of crescendo TIAs ( →OR!)
Management of pt with triple vessel heart disease and 90% R carotid (CEA +CABG)
Management of carotid if at time of surgery, completely thrombosed
Strikeouts
Not being clear on your pre-op indications Not differentiating from basovertebral ischemia Operating on fresh ipsilateral stroke
Not getting cardiac work-up, angiogram or MRA pre- op
Don’t start discussing things like anterior subluxation of the mandible to extend exposure unless you do this procedure!
Not being able to describe your operation or ways to minimize debris in ICA
Performing blind endarterectomy (need to visualize dis- tal endpoint to avoid distal flaps!)
Discussing carotid angioplasty/stents (only pt with clear fibromuscular dysplasia unresponsive to med- ical Tx gets dilatation)
Strikeouts 151
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