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.
  * 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.