Abstract
Causes of vertebrobasilar insufficiency (VBI) are multifactorial. Compromised vertebral blood flow due to atherosclerotic disease has been clearly outlined and its management fairly well standardized. On the other hand, insufficiency due to extraluminal factors such as osteophytes, fibrous bands, abnormal origin of the vertebral artery, and so forth has also been reported. However, its exact clinical significance is not well known and few attempts have been made to surgically correct this condition. In this report, the authors review recent experience in surgical reconstruction of the vertebral system, focus on the VBI caused by extrinsic extraluminal compression, and discuss the surgical management of this condition.
Fifty-four patients with symptoms of VBI were operated on 59 times. Among them, angiographically definitive evidence of impaired vertebral blood flow caused by extrinsic compression was demonstrated in 14 cases; 8 patients were male and 6 were female (mean age 58.6 years, range 22 to 76 years). At the V1 segment of vertebral artery, Powers' syndrome was found in 1 case, spondylotic VBI in 9 cases in the V2 segment, and at the V3 segment, Bow hunter's stroke in 3 cases and VBI caused by atlanto-axial dislocation in 1 case. For the patient with Power's syndrome, resection of anterior scalene and longus colli muscles, and removal of fibrous band were performed. All 9 patients with spondylotic VBI underwent the same surgical procedures, i.e. uncectomy and unroofing at the vertebral level concerned. For 2 of the 3 patients with Bow hunter's stroke unroofing and fibrous band removal were performed, and C1/2 posteior fusion was performed for one patient. For the patient with VBI due to atlanto-axial dislocation C1/C2 posterior fusion, surgical results were excellent. Vertebral artery flow regained in all cases without morbidity or mortality.
Therefore, unlike artherosclerotic stenosis, impairment of vertebral blood flow caused by extra-luminal factors is thought to be good indication for surgery, which obtained vertebral blood flow restoration safely and reliably.
