Tension pneumoventricle after resection of a fourth ventricle choroid plexus papilloma: An unusual postoperative complication.

Abstract Background: Pneumocephalus is defined as the presence of air within the intracranial vault. A common complication of head trauma and surgery, pneumocephalus is usually related to ventricular shunts, craniotomies, and surgery in the sitting position. Tension (symptomatic) pneumoventricle is a rare entity associated with significant clinical morbidity. Case Description: We report an unusual case of a 15‑year‑old girl with tension pneumoventricle developed shortly after removal of a choroid plexus papilloma of the fourth ventricle by a midline suboccipital approach while in the sitting position. Conclusion: The presence of a cerebrospinal fluid (CSF) diversion system that causes a decrease in intracranial pressure and the existence of a craniodural defect with or without an obvious CSF leak may be the cause of tension pneumoventricule. According to our present understanding, this is the first report of this peculiar complication of fourth ventricular surgery. We discuss clinical manifestations, surgical management, contributing factors, and mechanisms involved in the pathogenesis of tension pneumoventricle.