Slab maximum intensity projection images of rotational angiography are useful for evaluation of the perforating branch in a case of basilar artery incarceration secondary to clival fracture.

Background: In the event of clivus exhibiting longitudinal fractures, the basilar artery (BA) may become entrapped at the fracture site, although this occurrence is infrequent. Occlusion of bilateral BA perforators, accompanied by entrapment of the BA, can result in brainstem ischemia, which often leads to unfavorable outcomes. We report here the usefulness of slab maximum intensity projection (MIP) images of rotational angiography in evaluating the BA perforators. Case Description: A 73-year-old man fell from a two-meter stepladder and was transferred to the emergency department. His Glasgow Coma Scale score was 8. He had left hemiplegia. Head computed tomography (CT) revealed a diffuse subarachnoid hemorrhage; an acute epidural hematoma in the right middle cranial fossa; and fractures in the clivus, right frontal bone, right temporal bone, anterior and lateral wall of the maxillary sinus, zygomatic arch, and bilateral pyramidal bones. CT angiography revealed that the BA was entrapped within the clival fracture and exhibited signs of severe stenosis. Cerebral angiography was performed under general anesthesia. Angiography from the left vertebral artery showed severe stenosis of the BA, but there was no blood flow delay beyond the stenosis. The slab MIP images revealed the occlusion of perforators on the right side of the brainstem, situated at the level of the entrapped BA, as well as the occlusion of the right anterior inferior cerebellar artery. Due to concerns about the risk of bleeding from surgical repair, conservative treatment was performed. Anti-thrombotic treatment was not administered. One and a half months after the injury, his consciousness became clear. He had severe hearing loss due to a fracture of the bilateral pyramidal bone but was able to communicate with others in writing. The left hemiplegia remained. Six months after the injury, his modified Rankin scale was 4. Conclusion: Slab MIP images of rotational angiography proved instrumental in evaluating the perforators in a case where the BA was found to be entrapped in the clival fracture site. Patients with occlusion of the bilateral perforators have a poor prognosis and may consider surgical treatment. The utilization of the slab MIP image of rotational angiography in the evaluation of the perforators may prove beneficial in determining the indication for surgical intervention.