Screening for and Treatment of Blunt
Cerebrovascular Injuries Algorithm
Annotation for Point B
Although it has been suggested that screening of asymptomatic patients is futile,16–18 there is evidence that stroke rates are significantly lower in treated patients when compared with untreated patients.11,12,19 Moreover, the Denver group has demonstrated that screening and treatment of BCVI is cost effective.20 Identification of a high-risk group for screening has been debated in the literature. The fundamental mechanisms of internal carotid artery injury include:
(a) cervical hyperextension or hyperflexion with rotation, stretching the internal carotid artery over the lateral articular processes of cervical vertebral bodies C1–C3;
(b) direct cervical trauma;
(c) intraoral trauma; and
(d) basilar skull fracture involving the carotid canal.21,22
The vertebral artery is most commonly injured from C-spine injuries, especially subluxations and fractures of the foramen transversarium.23 Analyses of screening have identified the following list of high-risk factors for BCVI:9
(a) an injury mechanism compatible with severe cervical hyperextension with rotation or hyperflexion;
(b) Lefort II or III midface fractures;
(c) basilar skull fracture involving the carotid canal;
(d) closed head injury consistent with diffuse axonal injury with Glasgow Coma Scale score <6;
(e) cervical vertebral body or transverse foramen fracture, subluxation, or ligamentous injury at any level, or any fracture at the level of C1–C3;
(f) near-hanging resulting in cerebral anoxia; or
(g) seat belt or other clothesline-type injury with significant cervical pain, swelling, or altered mental status.
With the improved accuracy of noninvasive screening modalities, there is a tendency to liberalize screening in an attempt to capture all injuries, rather than restricting screening to groups with the highest risk.24–26 Broadened screening guidelines may include combined thoracic and cervical or cranial injuries, but there have not been any large-scale analyses to determine the yield of such protocols.