Cerebrospinal Fluid Leaks
Before we discuss treatment of cerebrospinal fluid rhinorrhea and sinus/anterior skull base defects we will need to review some definitions:
- Cerebrospinal fluid (CSF) leak - Extravasation of the fluid normally contained in the ventricles of the brain, the subarachnoid space and the central canal of the spinal cord through a hole in the lining of the brain or spinal cord (meninges). Within the realm of rhinology and endoscopic sinus surgery, CSF leak generally refers to watery, clear nasal drainage coming through a defect of the cranial base and meninges associated with the frontal, ethmoid or sphenoid sinuses. Likewise, a rhinologist-endoscopic sinus surgeon encounters meningoencephaloceles protruding through cranial defects in the frontal, ethmoid and sphenoid sinuses.
- Meningoencephalocele Protrusion of the brain and its lining (meninges) through a hole in the cranium.
- Meningocele - Protrusion of the lining of the brain (meninges) and cerebrospinal fluid through a hole in the cranium.
Two decades ago, cerebrospinal fluid (CSF) leaks, meningoencephaloceles and meningoceles involving the paranasal sinuses or nasal cavity were often managed through external (scalp) incisions and craniotomies (opening the bone of the skull with a saw). The introduction of nasal endoscopes and specialized endoscopic sinus and skull base instrumentation allows successful treatment of many of these anterior skull base lesions through the nose, thereby avoiding any incisions on the face and scalp. During an endoscopic repair of a cerebrospinal fluid leak (cerebrospinal fluid rhinorrhea) the surgeon clearly visualizes the leak from below and places a secure multilayer graft (usually readily harvested from the patient’s internal nasal tissues) to seal the leak. The endoscopic approach affords decreased patient discomfort, shorter hospitalization and in many cases, increased visualization for the surgeon during the procedure and during post-operative follow-up or surveillance. Treatment of these lesions via an endoscopic approach requires specialized training of the surgeon and operating room staff familiarity with dedicated endoscopic skull base instruments and computerized surgical navigation.