Emergency parent artery occlusion for ruptured parapharyngeal ICA infectious pseudoaneurysm in skull base osteomyelitis under transfer constraints.

Ruptured infectious pseudoaneurysm of the high cervical (parapharyngeal) internal carotid artery (ICA) complicating skull base osteomyelitis (SBO) is a life-threatening emergency, especially when active exsanguination makes immediate transfer unsafe. Although parent artery-preserving reconstruction is increasingly used, uncontrolled infection, massive transfusion requirements, and contraindications to dual antiplatelet therapy (DAPT) may preclude complex reconstruction. We describe a safety-first, transfer-constrained decision-support workflow for damage-control neurovascular care, integrating a decision matrix with a stepwise emergency parent artery occlusion (PAO) protocol. In our illustrative case, progressive lower cranial neuropathy (CN IX-XII) prompted urgent vascular imaging, which identified a left high cervical (parapharyngeal) ICA pseudoaneurysm adjacent to the carotid canal. Catastrophic epistaxis was controlled on-site within 58 minutes using PAO after rapid angiographic collateral verification, with only punctate ischaemic lesions and functional recovery (modified Rankin Scale score, 1). Using this illustrative case, we present a structured model for explicit, time-critical reasoning when biology and logistics favour deconstruction over reconstruction. Serial contrast-enhanced MRI at 3.5 and 8.6 months demonstrated continued improvement in skull-base inflammatory changes without pseudoaneurysm recurrence.