Intracranial vertebral artery dissections: clinical, radiological features, and surgical considerations.

We reviewed 24 patients with intracranial vertebral artery dissections treated during the last 12 years. Sixteen patients were admitted with subarachnoid hemorrhage (SAH) and 8 did not have SAH. The mean age at the time of onset was 50.0 years. Male preponderance was noted. Among 21 patients with acute onset, 6 (29%) experienced prodromal neck pain and 3 (60%) of 5 SAH patients showed nuchal stiffness when examined within 6 hours of onset. The preoperative angiographical findings were uniform in SAH cases in contrast to the varied angiographical findings seen in non-SAH cases. So-called pearl and string sign was observed in most SAH cases, but the "string" was often so short and wide that the term "constriction" appeared more suitable. From intraoperative observations, the angiographical point of constriction seemed to represent the proximal or distal end of dissection. As for treatment, 19 patients underwent 20 surgeries. Trapping was performed in eight surgeries, base clipping was performed in five, and proximal clipping was performed in seven. Both trapping and base clipping prevented further bleeding, but trapping was associated with a high rate of postoperative lower cranial nerve palsy. Postoperative neurological complications were less frequent after proximal clipping, but subsequent postoperative bleeding occurred in one patient treated by this technique. The overall long-term outcome in the surgically treated cases in our series was favorable, but most patients suffered from various degrees of uncomfortable dysphagia or hoarseness for some period after surgery. It was also noted that, in half of the disabled cases, the major disability was attributable to lower cranial nerve palsy and respiratory troubles that developed postoperatively.