A nasal cerebrospinal fluid leak (CSF leak) results from an abnormal communication between
the intracranial subarachnoid space and the nasal cavity. This may result in clear rhinorrhea and
dripping from the nose. This is usually unilateral. There are many potential etiologies of CSF
leaks which include traumatic, iatrogenic, congenital, spontaneous, and neoplasm. The most
common causes of iatrogenic leaks are endoscopic sinus surgery and neurological surgery such
as hypophysectomy/pituitary surgery.
Once a CSF leak is suspected, diagnosis and localization may be somewhat difficult. A fluid
sample can be sent for laboratory testing, specifically beta-2 transferrin or beta-trace protein
testing to confirm the presence of CSF. Once the presence of CSF is confirmed, imaging studies
such as CT, MRI, cisternography, and radionucleotide testing may be ordered.
If the diagnosis of CSF leak is made, repair is usually recommended as persistent leakage may
lead to meningitis, brain abscess, seizures, and death. While CSF leak repair was traditionally
performed via open craniotomy approaches, endoscopic repair is now considered standard of
Endoscopic repair is performed through the nose with the use of telescopes and specialized
instrumentation. Once the defect site is identified, meticulous endoscopic surgical repair
including the placement of multiple layered grafts is undertaken. A lumbar drain may be placed
prior to surgery; fluorescin dye may be administered through the drain to help with localization
of the defect. In addition the lumbar drain may be kept in place post-operatively to help alleviate
pressure on the repair site. Depending on the etiology of the leak, patients may be kept on strict
bed rest for 48-72 hours post-operatively, after which activity is slowly re-initiated. The success
rate of endoscopic CSF leak repair is greater than 90%.