SURGICAL TREATMENT OF PARTIAL EXTRALUMINAL
OCCLUSION OF FIRST PART OF VERTEBRAL ARTERY
S. ALLAN HURVITZ, M.D., F.A.C.A.

This report presents the clinical concept of hindbrain ischemia due to

partial extraluminal occlusion of a segment of the first part of the vertebral
artery. My first report on this subject presented 23 patients operated upon
between October 11, 1974, and July 25, 1975.~ This second report presents an
additional 8 patients operated upon between July 28, 1975, and October 3,
1975.
Partial extraluminal occlusion of a segment of the first part of the vertebral
artery is caused by kinking of the proximal vertebral artery, or by an alteration
of the normal take-off angle of vertebral from subclavian artery by upward
arching of the subclavian artery, with or without elongation of the vertebral
artery (Fig. 1). Partial extraluminal occlusion can also be caused by fibrous
tissue arising from the supra-pleural membrane, by perivascular fibrosis, or by
other tissue structures. Upward arching of left subclavian artery can be so
extreme as to cause kink occlusion of the subclavian artery itself. Upward
arching of the subclavian artery is caused by anatomic changes occurring with

the aging process.
z

CLINICAL MATERIAL

There were 31 patients with severe symptoms of hindbrain ischemia who
had an operation for correction of partial extraluminal occlusion of the
proximal vertebral artery between October 11, 1974, and October 3, 1975.
Seven of the 31 patients had staged bilateral procedures. There were 19
females and 12 male patients ranging in age from 25 to 90 years; 20 patients
were over 60 years of age and 3 patients were under 33 years of age. Aortic arch
angiography with visualization of the neck vessels through the transfemoral
route was performed pre-operatively on all patients by a radiologist. Seventeen patients had post-operative arch angiograms which showed patent
operated vertebral arteries in all.
For 3 months to 15 years pre-operatively, 28 of the 31 patients had a disorder
of equilibrium with an unsteady gait. Equilibrium was markedly improved
after operation in all of these patients.
An acute hemi-paresis resolved post-operatively in 4 patients. One patient’s
left hemi-paresis resolved in the presence of 90% stenosis of the right internal
carotid artery. A 58 year old male became hemiplegic on the right in January,
1975. Five months after the stroke he had difficulty walking with a cane; he
Address reprint requests to Dr. Hurvitz, Vertebral Artery Institute, 10921 Wilshire Blvd., Suite
907, Los Angeles, California 90024.
Read at the Twenty-second Annual Meeting of the American College of Angiology, Palm
Springs, California, January 7, 1976.
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FIG. 1. (Patient 20.) (A) Pre-operative angiogram shows upward arching of the subclavian and
kinking of the proximal vertebral artery just beyond its origin. (B) Post-operative study shows a
patent proximal vertebral artery.

depressed, unable to recognize relatives, and had an expressive dysphasia.
A pre-operative angiogram showed partial occlusion of the proximal right
vertebral artery and complete occlusion of the left internal carotid artery. An
operation on the right vertebral artery was performed on May 7, 1975. Cur-

was

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rently the patient is able to walk without a cane. He recognizes his relatives
and friends, understands everything spoken, is without depression, and the
expressive dysphasia has improved.
For 7 years a 53 year old female had a progression of a disorder of
equilibrium, dizziness, dysphagia, slurred speech, headache, decreased mental function, diplopia and blurred vision, slight motor weakness on the left,
disorder of urinary bladder control, and constipation. She had an elongated
first part of left vertebral artery with severe kinking of the vessel, without
upward arching of the subclavian artery (Fig. 2). Following an operation on
the left vertebral artery on April 25, 1975, the patient’s symptoms markedly
improved.
A 76 year old male for 10 years had a progression of a disturbed equilibrium,
dizziness, slurred speech, dysphagia and headache. He required assistance to
walk, and intermittently aspirated liquids. He was unable to hold a pen to
write. Bilateral staged operations on the vertebral arteries were performed. At
present he is able to walk with a cane, and hold a pen and write. Dysphagia
and headache are gone, and his speaking ability has improved.
Three patients, aged 25, 27 and 32, had a congenital type of partial
extraluminal occlusion of the left vertebral artery. Two had fibrous tissue from
the supra-pleural membrane compressing the proximal 1 centimeter of the
vertebral artery (Fig. 3). The third had fibromuscular tissue compressing the
same segment of vertebral artery. In this patient, microscopic study of the
tissue which compressed the proximal vertebral artery showed filaments of
skeletal muscle in a connective tissue stroma.
A 49 year old female with a 6 month history of a disorder of equilibrium,
slurred speech, headache, dizziness, and the loss of the ability to knit was
operated upon on March 27, 1975. She is not included among the 31 patients
because the pre-operative angiograms showed complete occlusion, non-visualization, of the left vertebral artery. At operation the proximal left vertebral
artery was found to be obliterated, represented by a few fibrous strands of
tissue, located 2 centimeters medial to the thyrocervical trunk. The thyrocervical trunk was compressed by fascial bands. There was extraluminal
occlusion of the costocervical trunk due to perivascular fibrosis and upward
arching of the subclavian artery. The costocervical and thyrocervical trunks
were mobilized and freed of compressing tissue. The costocervical trunk
measured 3 millimeters in diameter. The internal mammary and suprascapular arteries were ligated in continuity. An operative arteriogram was obtained
which demonstrated filling of the second part of the vertebral artery by
collateral flow through the deep cervical branch of the costocervical trunk
(Fig. 4). Post-operatively the patient showed marked improvement.
There was no mortality and no significant morbidity in this series. An
operation through a lower neck incision is well tolerated by elderly patients
with heart disease. An incision is made above the medial third of the clavicle.
The first part of the vertebral artery is mobilized as far distally as possible and
is freed from all compressing and adherent tissue.1

FIG. 2. (Patient 12.) (A) Pre-operative angiogram shows a kink of the first part of an elongated
left vertebral artery. (B) Post-operative angiogram shows a straightened first part of verbetral
artery without a kink.

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FIG. 3. (Patient 17.) (A) Pre-operative subtraction angiogram shows non-filling of the proximal
1 cm of left vertebral artery due to compressing congenital fibrous bands. (B) Post-operative
selective subclavian arteriogram shows a patent proximal vertebral artery.

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FIG. 4. Operative arteriogram shows filling of the second part of the left vertebral artery by
collateral flow from the deep cervical branch of the costocervical trunk in a patient with fibrous
obliteration of the proximal left vertebral artery. Operative arteriogram was done following the
surgical correction of extraluminal occlusion of the left costocervical trunk.
DISCUSSION

Decreased perfusion through either vertebral artery caused by partial
extraluminal occlusion, with or without carotid bifurcation arteriosclerotic
occlusive disease, can produce symptoms of hindbrain ischemia.
The vertebral artery supplies the brainstem and the inferior aspect of the
cerebellum. The symptoms of hindbrain ischemia include: disorder of
equilibrium with an unsteady gait, difficulty balancing on 1 foot, dizziness in
the upright position, difficulty in writing and knitting, slurred speech,
headache, dysphagia, vertigo, tinnitus, drop attack, drowsiness, excessive
sleeping, decrease of mental capacities, diplopia, blurred vision, syncopal
attacks, hemiparesis, hypesthesia, and tremor. Most of these symptoms are
partially reversible after an operation to correct a partially occluded vertebral
artery, even with a 10 to 15 year progressive history.
Poiseuille’s Law states that volumetric flow rate is proportional to the fourth
power of the diameter of a circular tube. In other words, increasing the
diameter of a narrowed vertebral artery 10 times, increases blood flow 10,000
times.

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SUMMARY

This report presents the clinical concept of hindbrain ischemia due to
partial extraluminal occlusion of a segment of the first part of the vertebral
artery, and submits a definite method of surgical treatment. Thirty one
patients with vertebral artery insufficiency are presented who had operations
with striking post-operative symptomatic improvement. Operative selection
of patients is dependent on aortic arch angiography with visualization of the
neck vessels. There was no mortality and no significant morbidity in this
series.
S. Allan Hurvitz, M.D., F.A.C.A.
Vertebral Artery Institute
10921 Wilshire Boulevard
Suite 907
Los Angeles, California 90024
REFERENCE
1. Hurvitz, S. A.: Surgical treatment of partial extraluminal occlusion of vertebral artery. Surg.
Gynecol. Obstet. In press.