Endoscopic Management of Cerebrospinal Fluid Leaks and Encephaloceles

Abstract

Cerebrospinal fluid (CSF) leak results from the breakdown of barriers separating the intracranial space and the paranasal sinuses. CSF rhinorrhea is the leakage of cerebrospinal fluid from the subarachnoid space into the nasal cavity due to defect in the dura, bone, and mucosa. This may be induced by traumatic, iatrogenic, congenital, neoplastic, or inflammatory processes. CSF rhinorrhea may develop directly from the anterior cranial fossa or indirectly through the middle or posterior fossa via the eustachian tube. A CSF leak may be associated with encephalocele, which is the herniation of neural tissue through the skull base. CSF leaks bring the risk of meningeal or intracranial infections, and therefore they should be treated as soon as the diagnosis is made. The surgical management of CSF leak has changed significantly following the introduction of endoscopic sinus surgery in the treatment of rhinosinusitis. Thanks to low morbidity and high success rate, the endoscopic transnasal technique for the repair of CSF rhinorrhea of the anterior cranial base replaces the open intracranial approaches in most cases. Endonasal endoscopic approach is preferred for the repair of CSF leaks, located at the anterior or posterior ethmoid roof and in the sphenoid sinus. CSF leaks, located at the posterior wall of frontal sinuses, can be repaired extradurally with osteoplastic flap approach to the frontal sinus.