Internal carotid artery agenesis presenting with ruptured Acom aneurysm: Rare case report.

Developmental anomalies of internal carotid artery (ICA), being rare entities, are mostly asymptomatic by themselves because of good collateral supply. However, when present with other associated intracranial anomalies requiring treatment, there can be catastrophic consequences, if special attention is not paid to this condition. We present a case of 36 years old male, who reported to our emergency department with complaints of headache and loss of consciousness. He was diagnosed as a case of ruptured anterior communicating aneurysm with subarachnoid hemorrhage and agenesis of left ICA with trans-cavernous anastomosis. He underwent clipping of aneurysm and was discharged uneventfully. This report highlights the importance of skillful microsurgical clipping in extremely high-risk conditions, in contemporary era of hybrid neurosurgeons.