P101 Aneurysm originating from embyological variant primitive lateral basiloveertebral anastamosis

<h3>Introduction</h3> The primitive lateral basilovertebral anastomosis (PLBA) is an embryonic longitudinal channel connecting developing branches of the vertebrobasilar system. It represents the cranial equivalent of the posterior-lateral spinal artery. <h3>Aim of Study</h3> We report a case of aneurysm arising from such an anomaly. <h3>Methods</h3> A 38-year-old male presented with headache and sudden unconsciousness. CT scan revealed subarachnoid hemorrhage (SAH) and intraventricular bleed. Cerebral angiogram showed an aneurysm arising from the connection between the right vertebral artery and the posterior inferior cerebellar artery (PICA) to the anterior inferior cerebellar artery (AICA), a remnant of PLBA. <h3>Results</h3> Coiling was performed through the left vertebral artery due to significant spasm in the right vertebral artery. The patient recovered post operatively. <h3>Conclusion</h3> PLBA is an embryonic channel linking lateral branches of the vertebrobasilar system. Knowledge of such anatomical variants is essential for Neuroradiologists managing aneurysms from these anomalies. <h3>Disclosure of Interest</h3> no.