Abstract
Many reports have suggested that blunt cerebrovascular injuries (BCVIs) potentially carry the risk of devastating complications, which occur in approximately 1% of all blunt trauma patients. Biffl et al., proposed a classification called the Denver grading scale that classified BCVIs based on their radiological features, which are significantly associated with the incidence of stroke. However, therapeutic strategies should be determined by the zones of occurrence of BCVIs, which are often more important than the morphological differences between them. Hence, in the current study, we classified BCVIs based on their zones of occurrence and investigated the stroke rate, prognosis, and the most effective treatment for each zone. Between October 2001 and September 2008, 32 patients with BCVIs in 36 vessels were diagnosed at our hospital according to the screening protocol based on the radiological examinations. They were classified into 3 groups based on the zones of occurrence: the cervical zone was zone 1, the transitional zone of neck and intracranial space was zone 2, and the intracranial zone was zone 3. Although vertebral artery injuries were found to be the major type of injury (72%) in zone 1, they were rarely found in the other 2 zones. On the Denver grading scale, 90% of BCVIs in zone 1 were grades II and IV, while 80% of those in zones 2 and 3 were grade V. For each zone, stroke rates were 11%, 62.5%, and 80% and mortality rates were 5.6%, 50%, and 30% respectively. In zone 1, 61% of patients received interventional radiology (IVR) and antithrombotic therapy, while others received antithrombotic therapy only. The rate of IVR in zone 2 and 3 were 50% and 12.5% whereas those of direct surgery was 20% and 40%, respectively. In zone 1, the stroke rate was lower, indicating the effectiveness of IVR in preventing stroke. In contrast, the mortality rate of zone 2 BCVI was the highest; 3 out of 4 patients who received IVR died due to uncontrollable bleeding. Although the stroke rate was highest in zone 3, the mortality rate of zone 3 was lower than that of zone 2. In zone 3, direct surgery and IVR were often effective against stroke. In summary, IVR and direct surgery are effective preventive treatments against stroke in zones 1 and 3, respectively. Therapeutic strategy for zone 2 BCVI remains an unanswered issue because of the difficulty associated with access for IVR, or direct surgery.
