Fenestration of the Extracranial Vertebral Artery

Abstract

STUDY DESIGN: A case report on fenestration of the extracranial vertebral artery found at forensic autopsy. OBJECTIVE: To describe an extracranial vertebral artery fenestration involving the subaxial cervical region, assessed radiographically and angiographically at forensic autopsy, in a young man. SUMMARY OF BACKGROUND DATA: Duplications or fenestrations of the extracranial course of the vertebral artery are rare and seen almost exclusively as a coincidental finding in angiographic studies. The terms "fenestration" and "duplication" are often incorrectly used synonymously. The former describes the passage of the duplicated vessel within the vertebral foramen transversarium, whereas the latter refers to the duplicated vessel coursing additionally through the spinal canal. The reported cases describing duplication are more common. Only three cases of vertebral extracranial fenestrations, involving only the upper cervical spinal segments, have been described in the literature. RESULTS: Angiography showed a fenestration of the vertebral artery localized between the intervertebral spaces of C2-C3 and C3-C4. At dissection, the vertebral artery appeared as a single vessel in the area of the fenestration. Histologically, a distinct difference in the thickness and composition of the vessel walls was found between the two vessel trunks. At autopsy, no further anomalies were observed in the vessels supplying the brain, which is contrary to the commonly held belief that fenestration is frequently associated with vascular malformations. CONCLUSION: Fenestration of the extracranial course of the vertebral artery is a developmental or congenital anomaly. A review of the literature demonstrated that this is apparently only a coincidental finding and has no pathologic significance.