Intracranial Vertebral Artery Stenting

 

 
72 years old Mr. Jamit Singh Dogra, had undergone Heart bypass surgery in 2007 for severe three-vessel coronary artery disease. In 2008 he had recurrent episodes of reversible paralytic strokes (TIA) in the territory of the Right middle cerebral artery. After investigations, he was found to have critical narrowing (stenosis) of the right Carotid artery. He had undergone successful Carotid artery stenting for carotid artery stenosis. This procedure was done at Fortis hospital Mohali by Dr. Harinder Bali. He remained symptom-free for the next two years. One month ago he started getting episodes of severe giddiness. Symptoms were so severe that he was unable to sit without becoming severally dizzy. He was admitted to the emergency department of Fortis hospital last month. His CT angiography showed that he had critical stenosis in the left Vertebral artery. There was two critical stenosis in the same artery. The first stenosis was 90 percent, just at the origin of the left Vertebral artery from the left subclavian artery. The second 90 percent long segment stenosis was present in the intracranial part of the vertebral artery just before it joins the other Vertebral artery to form the Basilar artery. This part of the vertebral artery is situated on the under the surface of the posterior part of the brain. The vertebral arteries arise from the subclavian arteries, one on each side of the body, then enter deep into the transverse process of the level of the 6th cervical vertebrae (C6). They then proceed superiorly, in the transverse foramen (foramen transversarium) of each cervical vertebra until C1. This path is largely parallel to, but distinct from, the route of the carotid artery ascending through the neck. At the C1 level, the vertebral arteries travel across the posterior arch of the atlas through the suboccipital triangle before entering the foramen magnum.
Inside the skull, the two vertebral arteries join up to form the basilar artery at the base of the medulla oblongata. The basilar artery is the main blood supply to the brainstem and connects to the Circle of Willis to potentially supply the rest of the brain if there is the compromise to one of the carotids. At each cervical level, the vertebral artery sends branches to the surrounding musculature via anterior spinal arteries.
 
Considering the severe symptoms of the patient, Dr. Bali decided to treat the two sites of stenosis in the vertebral artery by vertebral artery angioplasty and stenting.
No open surgery was possible because of the location of the stenosis in the intracranial part on the under the surface of the brain. The procedure was carried out under local anesthesia from the femoral route. Two balloon-mounted stents were used to treat the two sites of stenosis. 6x15 mm Stent was used to treat the stenosis at the origin of the left vertebral artery and 3.5x38 mm balloon mounted stent was used to treat the stenosis in the intracranial part of the vertebral artery. Dr. Bali informed that the entire procedure took about 30 minutes. The patient made an uneventful recovery and was walking the next day. His symptoms were completely treated and he was discharged after three days. ACT angiography was done few days after the procedure showed that both stents in the vertebral artery are functioning normally and the blood supply to the brain is normal. It has been almost a month since this procedure was performed and the patient is fine and free of symptoms. “ This is the first time intracranial part of the vertebral artery stenosis has been treated by stenting in this region “ informed Dr. Bali. He said that we have treated intracranial carotid artery stenosis, earlier by stenting but this is the first case of intracranial vertebral artery stenting in this region. He further said that the procedure is technically challenging as the approach to intracranial part is very complicated and the artery is lying just under the surface of the brain.  A thorough knowledge of the anatomy of the region, special hardware, and a very high-resolution imaging equipment is prerequisite for performing this procedure.  As there is thick bone al around the procedure can only be performed under subtraction imaging, added Dr. Bali. Dr. Bali has performed more than 120 carotid artery stenting to treat patients who are at a risk of paralytic strokes. Dr. Bali cautioned that symptoms like sudden giddiness, unsteady gait, or double vision can be due to ischemia of the posterior part of the brain. Such symptoms should be investigated by Doppler or CT angiography. If stenosis of the arteries supplying blood to the brain is detected, it can be treated non surgically by angioplasty and stenting.