The significance of carotid canal involvement in basilar cranial fracture.

Abstract

Basilar cranial fractures have been associated with injury to the carotid artery. We sought to determine whether fracture through the carotid canal was a significant risk factor for carotid injury. A retrospective chart review was performed, and 230 patients with basilar cranial fractures were identified. Fifty-five of the 230 patients had visible fractures that extended through one or both carotid canals (CC fx group). Evidence for vascular injury, based on medical records, angiography, magnetic resonance imaging, and other studies, was compiled. The anatomic characteristics of the fractures were also noted and recorded. Ten patients in the CC fx group suffered vascular complications; for six of them, the complications were directly related to the intracranial carotid artery. This compares to four patients in the non-CC fx group with vascular complications (P < 0.005), only one of which was carotid-specific (P < 0.005). The most common site of fracture through the canal was at the junction of the lacerum and cavernous portions of the canal (the spheno-occipital suture) (62% of all carotid canal fractures occurred at that site); however, vascular injury was seen most often in patients who sustained fractures through the petrous segment (67% of carotid canal-specific injuries occurred in that group, and 25% of patients with petrous canal fractures suffered carotid injury, [P = not significant]). The mean Glasgow Coma Scale score and the mean age were both lower (P < 0.05) in the CC fx group. Vascular complications are more frequently observed after basilar cranial fractures when there is involvement of the carotid canal. The lacerum-cavernous junction, which is partly formed by the spheno-occipital suture, is the most frequently fractured segment of the carotid canal. Fracture through the petrous segment of the carotid canal is associated with a relatively high incidence of carotid injury. Fracture through the carotid canal may serve as an index of injury severity, because patients with these fractures suffered more severe head injuries.