CMS Pub. 100-03, ch. 1, § 20.1

CIM 35-32

Obstructions which block the flow of blood through the vertebral artery can cause

vertigo, visual or speech defects, ataxia, mental confusion, or stroke. These symptoms in

patients result from reduction in blood flow to the brain and range from symptoms of

transient basilar ischemia to mental deterioration or completed stroke.

Five types of surgical procedures are performed to relieve obstructions to vertebral artery

blood flow. They are:

• Vertebral artery endarterectomy, a procedure which cleans out arteriosclerotic

plaques which are inside the vertebral artery;

• Vertebral artery by-pass or resection with anastomosis or graft;

• Subclavian artery resection with or without endarterectomy;

• Removal of laterally located osteophytes anywhere in the C6 (C7)-C2 course of

the vertebral artery; and

• Arteriolysis which frees the artery from surrounding tissue, with or without

arteriopexy (fixation of the vessel).

These procedures can be medically reasonable and necessary, but only if each of the

following conditions is met:

• Symptoms of vertebral artery obstruction exist;

• Other causes have been considered and ruled out;

• There is radiographic evidence of a valid vertebral artery obstruction; and

• Contraindications to the procedure do not exist, such as coexistent obstructions of

multiple cerebral vessels.

Angiograms documenting a valid obstruction should show not only the aortic arch with

the vessels off the arch, but also show the vessels in the neck and head (providing biplane

views of the carotid and vertebral vascular system). In addition, serial views are needed

to diagnose “subclavian steal,” the condition in which subclavian artery obstruction

causes the symptoms of vertebral artery obstruction. Because the symptoms are not

specific for vertebral artery obstruction, other causes must be considered. In addition to

vertebral artery obstruction, the differential diagnosis should include various degenerative

disorders of the brain, orthostatic hypotension, acoustic neuroma, labyrinthitis, diabetes

mellitus and hypoglycemia related disorders.

Obstructions which can cause symptoms of blocked vertebral artery blood flow and

which can be documented by an angiogram include:

• Intravascular obstructions - arteriosclerotic lesions within the vertebral artery or in

other arteries.

• Extravascular obstructions;

• Bony tissue or osteophytes, located laterally in the C6 (C7)-C2 cervical vertebral

area course of the vertebral artery, most commonly at C5 -C6;

• Anatomical variations - Anomalous location of the origin of the vertebral artery, a

congenital aberration, and tortuosity and kinks of the vertebral artery; to

• Fibrous tissue - Tissue changed as a result of manipulation of the neck for neck

pain or injury associated with hematoma; external bands, tendinous slings, and fibrous

bands.

The most controversial obstructions include vertebral artery tortuosity and kinks and

connective tissue along the course of the vertebral artery, and variously called external

bands, tendinous slings and fibrous bands. In the absence of symptoms of vertebral

artery obstruction, vascular surgeons feel such abnormalities are insignificant. Vascular

surgery experts, however, agree that these abnormalities in very rare cases do cause

symptoms of vertebral artery obstruction and do necessitate surgical correction.

Vertebral artery construction and vertebral artery surgery are phrases which most

physicians interpret to include only surgical cleaning (endarterectomy) and bypass

(resection) procedures. However, some physicians who use these terms mean all

operative manipulations which remove vertebral artery blood flow obstructions. Also,

some physicians use general terms of vascular surgery, such as endarterectomy, when

vertebral artery related surgery is performed. Use of the above terminology specifies

neither the surgical procedure performed nor its relationship to the vertebral artery.

Therefore, in developing claims for this type of procedure, require specific identification

of the obstruction in question and the surgical procedure performed. Also, in view of the

specific coverage criteria given, develop all claims for vertebral artery surgery on a case-by-case basis.

Make payment for a surgical procedure listed above if: (1) it is reasonable and necessary

for the individual patient to have the surgery performed to remove or relieve an

obstruction to vertebral artery flow, and (2) the four conditions noted are met.

In all other cases, these procedures cannot be considered reasonable and necessary within

the meaning of §1862(a)(1) of the Act and are not reimbursable under the program.