Tension Pneumocephalus: A Potentially Fatal Complication of Expanded Endoscopic Endonasal Approach.

While some volume of pneumocephalus occurs following any surgery entailing dural breach, tension pneumocephalus (TP) is a rare complication of endoscopic endonasal surgery described in less than 1% cases including expanded endoscopic endonasal approaches (EEEA). It is a neurosurgical emergency warranting urgent decompression. Two cases, who developed TP following EEEA are presented. One had sinonasal malignancy (adenoid cystic carcinoma) eroding the anterior skull-base (T4N0M0) and the other was a large olfactory groove meningioma. TP was heralded in both by sudden deterioration in neurological status. Both cases underwent bifrontal craniotomy for decompression with simultaneous skull-base repair incorporating a vascularised pericranial flap. Brief literature review regarding the pathophysiology, contributing factors, diagnosis, management, and prevention of TP following EEEA is presented. TP, a life-threatening neurosurgical emergency, warrants meticulous precautions for its prevention, and vigilant postoperative monitoring for early detection. Urgent decompression with thorough skull-base repair is imperative to prevent complications.