C7横突起骨折による椎骨動脈閉塞の1例

A Case of Vertebral Artery Occlusion Caused by Transverse Process Fracture of C7

はじめに

　外傷性椎骨動脈損傷は稀な外傷であるとされていたが，近年，報告が増加しつつある外傷の1つである。頸椎損傷に伴うことが多いとされており，その臨床像は無症候性から重篤な脳虚血症状をきたすものまでさまざまである。今回われわれは，C7横突起骨折によって無症候性椎骨動脈閉塞をきたした症例を経験し，損傷のメカニズム，診断，治療などについて考察したので報告する。

Abstract

　Traumatic vertebral artery injuries are frequently accompanied by cervical spine injury.　Transverse process fracture from C6 to C1 has been reported as a high risk factor for vertebral artery injury.

　We report a rare case of vertebral artery occlusion caused by transverse process fracture of C7.　A 22-year-old man was admitted to our hospital after a motor-cycle accident.　Neurological examination revealed almost normal findings.　Axial computed tomography (CT) at the C7 level revealed soft-tissue swelling of the neck and right transverse process fracture.　Further, a bony fragment protruding in the anterolateral direction was observed.　Magnetic resonance (MR) image showed normal findings.　MR angiography (MRA) revealed right vertebral artery occlusion at the V1 segment.　Vertebral artery angiography revealed right vertebral artery occlusion, normal basilar artery, and retrograde flow of the right vertebral artery.　The patient was treated with heparin and aspirin and discharged 28 days after admission.　A follow up MRA at 2 months after admission demonstrated no change in right vertebral artery occlusion, and he was still asymptomatic 3 months after admission.　We conclude that the transverse process fracture of C7 complicated with soft-tissue swelling of the neck could cause vertebral artery injury, and MRA and angiography are recommended for diagnosis and treatment, respectively.