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Bypass graft to Lateral Tarsal Artery. Click to enlarge.

Distal Bypass
Cardiac Evaluation of Vascular Patients
Amputation Prevention in Diabetics
Indications for Carotid or Vertebral Artery Surgery
Pulmonary Embolism
Chronic Venous Insufficiency
Hemodynamic Monitoring in Vascular Patients
Cost Effective Critical Care
Multdetector CT for TOS
Miscellaneous Articles

  

Indications for Carotid Surgery or Vertebral Artery Surgery

Carotid Endarterectomy

Vascular surgeons have been convinced for many years of the value of carotid endarterectomy in the prevention of stroke. Many physicians have disagreed, pointing to the incidence of stroke associated with the operation itself. Major published controlled series of the past few years have not only clarified the issues pertaining to carotid surgery but have been generally accepted by the medical community. These studies form the basis for the modern management of cerebrovascular disease, and I would like to review them briefly.

The North American Symptomatic Carotid Endarterectomy Trial (NASCET) reported in 1991 studied 669 symptomatic patients with a carotid stenosis of 70% or greater. The patients were randomized into medical or surgical groups. Medically treated patients were treated using the regimen often attributed to "contemplative physicians." 26% had strokes within 2 years. Of the surgically treated group 9% had strokes. Risk reduction of ipsilateral stroke due to surgery was 17% +/-3.5 p<.0001. Risk reduction of fatal stroke was 10.6% +/- 2.6 p<.001.1

The European Carotid Surgery Trial (ECST) also published in 1991 studied 879 patients collected over 10 years with 70% or greater stenosis randomized into medical or surgical therapy. The 3 year stroke rate among medical patients was 21.9% and among surgical patients was 12.3%, even though the 30 day stroke and death rate was high by current American standards. They concluded that successful carotid surgery produced a 6 fold reduction in strokes (p<.0001).2

The Veterans Administration (VA) Carotid Endarterectomy Trial for Symptomatic Stenosis studied 190 symptomatic patients with carotid stenosis 50% or greater randomized into medical or surgical therapy. At a mean follow-up of 11.9 months there was a significant reduction in stroke or crescendo transient ischemic attacks (TIA) in patients who underwent carotid endarterectomy (7.7% vs 19.4%). The relative risk reduction was 60% (p=.011).3

The VA Carotid Endarterectomy Trial for Asymptomatic Carotid Stenosis was reported in 1993. In that study 444 asymptomatic patients with carotid stenosis of 50% or greater were randomized into medical or surgical therapy. Again surgical patients did much better than medial patients. Of the surgical patients the incidence of stroke at 4 years was 4.7% with 8.0% having other neurological events. Medical patients had a 9.4% incidence of strokes and a 20.6% incidence of other neurological events. This study included a high risk and aged group of patients who had a stroke and death rate at 4 years of over 40% .4 Surgical patients lived out their lives without the morbidity of neurological events and that is the usual patient's goal.

Finally, the Asymptomatic Carotid Artery Stenosis study (ACAS), published in 1995 randomized 1662 patients with stenosis of 60% or greater into best medical therapy or best medical therapy plus surgery. The 5 year stroke rate for surgical patients was 5.1% and for medical patients 11%. These favorable statistics were achieved even though of the 17 strokes in the surgical group 2 occurred after randomization but before surgery and 5 were from the arteriogram. The beneficial effect of carotid endarterectomy in these asymptomatic patients was realized in only 10 months.5 This study was terminated early because of these findings and the physicians participating in the study were notified and advised to reevaluate unoperated patients. In an unusual move, the National Institutes of Health sent a Clinical Advisory to every physician in the country on 28 September 1994. This advisory preceded formal publication and was sent so that the findings could be acted upon by practicing physicians immediately. You and the members of the panel undoubtedly received a copy of this advisory.6 The importance of carotid surgery for asymptomatic patients with 60% stenosis was then front page news throughout the United States.7

Last year the Department of Surgery, the Cardiovascular Surgery Section and the Quality Management Department of Presbyterian St. Lukes Medical Center, Denver, Colorado, decided to adopt the criteria of the ACAS study as the screening criteria for appropriateness of carotid surgery and the results reported in that study as the results our surgeons were expected to achieve. Review of two years of data found the Department in compliance both with indications and results.

Vertebral Artery Reconstruction

Vertebral artery surgery is much less common than carotid surgery, and is usually the province of the Certified Vascular Surgeons. Vertebral territory symptoms are quite nonspecific and may even alternate from side to side with different attacks. Vertebrobasilar symptoms are usually a manifestation of global brain ischemia, as a complex collection of lesions in the extracranial cerebral circulation and the Circle of Willis are found. Clouding of consciousness, confusion, unconsciousness and drop attacks are characteristic of this condition and have been recognized since the first description of the syndrome in 1955.8 Virtually every textbook written since which mentions vertebral basilar insufficiency or global cerebral ischemia describes this.9 Note that a proximal vertebral reconstruction is carried out thru the same incision as a carotid endarterectomy, and repairing both lesions at the same time makes logistical sense. The indications for this surgery are discussed in most of the vascular surgical texts. There are three accepted indications for repair, a symptomatic lesion, global ischemia of the brain, or an asymptomatic lesion of a single dominant vertebral repaired in conjunction with a planned carotid reconstruction.10 Workup of the lesion involves ruling out other causes of the nonspecific symptoms, and may include cardiology consultation, neurology consultation, Holter monitoring, EEG, CT or MR scan of the brain or cerebral angiography. Addition of a proximal vertebral reconstruction adds little mortality and morbidity to a well-performed carotid endarterectomy.

Dr Brantigan wrote this article in 1997

1 North American Symptomatic Carotid Endarterectomy Trial Collaborators, Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade carotid stenosis, N Engl J Med 325:445-53 (1991)

2 European Carotid Surgery Trialists' Collaborative Group, MRC European carotid surgery trial: interim results for symptomatic patients with severe (70-99%0 or with mild (0-29%) carotid stenosis, Lancet 337:1235-43 (1991)

3 Mayberg, MR. et al, Veterans affairs cooperative studies program trial for carotid endarterectomy in patients with symptomatic carotid stenosis, in Moore, WS, Surgery for Cerebrovascular Disease, WB Saunders.

4 Hobson, RW et al, Efficacy of carotid endarterectomy for asymptomatic carotid stenosis, N Engl J Med 328:221-7 (1993)

5 Executive Committee for the Asymptomatic Carotid Atherosclerosis Study, Endarterectomy for asymptomatic stenosis, JAMA 273:1421-8 (1995)

6 National Institute of Neurological Disorders and Stroke, Asymptomatic Carotid Atherosclerosis Study (ACAS) Clinical Advisory 28 September 1994.

7 New York Times, 1 October 1994 p1.

8 Millikan, CH et al, Studies in cerebrovascular disease. I The syndrome of intermittent insufficiency of the basilar arterial system, Proc Staff Meetings Mayo Clinic, 30:61-68 (1955)

9 Gelabert HA and Moore WS, Carotid endarterectomy: Current Status, Current Problems in Surgery 28:183-262 (1991). "Global events are manifested by vertigo, dizziness, ataxia, or syncope. These symptoms are associated with brain stem or posterior circulatory dysfunction. Unlike the carotid embolic events, these symptoms are often associated with diminished flow.

Encyclopedia Britannica CD Version 2.0. "..brief reduction in consciousness, vertigo, slurred speech, impaired vision in both eyes or imbalance point to ischemia in the vertebrobasilar circulation."

Berkow, R, ed, Merck Manual 1992, "..confusion, vertigo, weakness, drop attacks, slurred speech......."

Horn, GV, Cerebrovascular Disease, Disease a Month June 1973, "Vertebrobasilar insufficiency may be manifested by vertigo, ataxia, hemianopia, nausea, drop attacks, perioral numbness, facial weakness, or a variety of sensory deficits.."

Scientific American Medicine, "...attacks of vertigo, unsteadiness, drop attacks, memory loss, confusion, retrograde amnesia..."

10 Berguer, R, Vertebrobasilar ischemia: Indications, techniques and results of surgical repair, in Rutherford, RB, Vascular Surgery p1392ff, 1989


2003-2004 Dr. Charles Brantigan,  Vascular Surgery Practice
2253 Downing Street, Denver, CO 80205
303.830.8822 fax: 303.830.7068 or 800.992.4676  inquiries@drbrantigan.com

Last Updated: 07/15/2004