Extracranial Vertebral Artery Disease

As early as 1844, Quain1 described the anatomy and operative surgery of the extracranial vertebral artery in lithographic drawings. In 1893, Matas2 described the contributions made in the early 1800s by other sur geons such as Dietrich, Velpeau, and Maisonneuve for the treatment of penetrating trauma to the vertebral artery. In 1831, Dietrich first proposed ligating the dis tal vertebral artery in the occipital-atloid region. In 1833, Velpeau ligated the vertebral artery at its proxi mal portion. Twenty years later, Maisonneuve success fully ligated the vertebral artery at the transverse fora men of the sixth cervical vertebra for a stab wound to the neck. The patient later died from a cerebral septic embolism. As the discovery of extracranial vertebral artery dis ease became more extensive, new methods of treatment evolved. Pathologic injury to the vertebral artery, caused by erosion of its wall by a tuberculous abscess, was repaired by ligation by Smythe in New Orleans in 1864. Alexander3 also used ligature of the vertebral arteries to treat epilepsy, sometimes ligating both arte ries at the same time. Elective ligation of the vertebral artery was also used to treat aneurysms. In 1888, Matas2 was the first surgeon who did not rely on ligation of the vertebral artery as treatment but fully excised an aneurysm between the occiput and the atlas through a posterior approach. For the next 50 years, few advances were made in the medical treatment of extracranial vertebral disease until Moniz4 performed the first vertebral angiogram in 1927 (Moniz won the Nobel Prize not for this discov ery but for the prefrontal lobotomy). Radner5 first re ported selective angiography of the vertebral artery. This technique allowed researchers to correlate occlusive disease with symptoms. In 1946, Kubik and Ad ams6 first described basilar artery insufficiency caused by thrombosis of the basilar artery. Ten years later at the Mayo Clinic, Millikan and Siekert7 reported studies of cerebrovascular disease and the syndrome of inter mittent insufficiency of the basilar arterial system. They introduced the use of anticoagulation drugs in the treatment of thrombosis of the basilar artery and noted a substantial reduction in the incidence of brainstem infarctions.8 With this revolution in the diagnosis of diseased arteries, more aggressive surgical techniques were de veloped. The cause of brain ischemia was assumed to be hypoperfusion, with the solution being revascularization. In 1958, Crawford and coworkers9 presented their results of surgical treatment of brainstem ischemia by reconstructing the vertebral artery after removing atherosclerotic plaque. The next year, Cate and Scott10 first described the technique of trans-subclavian endarterectomy of the subclavian-vertebral artery. In 1961, angiography allowed Reivich and col leagues11 to describe the process of reversed flow in the vertebral artery with proximal left subclavian ste nosis in two patients with associated neurological dys function. This phenomenon was called subclavian steal syndrome. Angiography also allowed visualization of other causes of extracranial vertebral artery disease, including extrinsic compression of the vertebral artery by osteophytes,12 constricting bands,13 and rotational obstruction,14 all of which were diagnosed and treated by surgical decompression. Angiography also provided the first extensive coop erative study of the incidence of extracranial arterial stenosis caused by atherosclerotic lesions in patients with cerebrovascular insufficiency. In 1968, stenosis was defined as a compromised lumen of more than 50% by the Joint Study of Extracranial Arterial Occlusion.15 Of 4748 patients, 80% had four-vessel angiograms that were categorized by location of the arterial stenosis. For the first time, this study provided a frequency distribution of surgically accessible sites with stenosis caused by atherosclerosis of the extracranial vertebral artery.15 As microsurgery evolved in the 1970s, various re constructive techniques also developed. Wylie and Ehrenfeld16 first treated pathology of the proximal verte bral artery by the transposition technique, with anastomosis between the vertebral artery and the com mon carotid artery (CCA). Berguer and associates17 used vein grafts in this region of the vertebral artery to connect the subclavian artery to the proximal vertebral artery. In January 1977, Carney and Anderson18 per formed the first vein bypass from the CCA to the distal vertebral artery at the level of Cl and C2. Subsequently,