Dissecting aneurysm of the V4 segment of the vertebral artery

Case contributed by Bruno Di Muzio


Sudden and the worse headache ever. Grade IV SAH was identified on a secondary hospital CT. The patient was transferred to a tertiary center to further treatment and investigation.

Patient Data

Age: 60-year-old
Gender: Male

Cerebral angiogram (DSA) - selected images


Procedure and findings: Intubated patient brought from from ICU after EVD insertion. With informed consent.

Right groin approach ( 5-French sheath ) bilateral common carotid, and vertebral artery angiography was performed with 3D acquisition of the left vertebral. A dissecting aneurysm of the V4 segment of the left vertebral artery distal to the left PICA origin. The dissection appears to extend up to the proximal basilar as well. The aneurysm measures 8.9x6.7 mm in dimensions. Both PCOM are prominant with good cross circulation. No other aneurysms, arteriovenous malformation or dAVF present.Hemostasis with 6F angioseal.

Conclusion: Dissecting aneurysm involving the V4 segment of the left vertebral artery with dissection extending to the proximal basilar artery. ​

New right gaze palsy and left pupil non-reactive

Technique: Non-contrast images through the brain have been obtained.

Findings: Reference is made with previous DSA. Comparison is made with external CT (not shown).

Hyperdense subarachnoid hemorrhage is seen predominantly surrounding the brainstem and extending inferiorly through the foreman magnum surrounding the basilar artery in keeping with site of dissection. Hemorrhage is also seen within the perimesencephalic cisterns, left sylvian fissure, temporal horns of the lateral ventricles, third and fourth ventricles. There has been redistribution of blood products but no evidence of interval bleed.

No subfalcine, tonsillar or uncal herniation.

Right frontal approach EVD terminates inferior to the anterior horn of the left lateral ventricle. Ventricular pattern is stable. No evidence of acute ischemia.

Conclusion: Extensive subarachnoid hemorrhage in keeping with vertebral and basilar artery dissection. No interval hemorrhage evident.

Case Discussion

This case illustrates a distal vertebral artery dissecting aneurysm and related SAH.

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