What is a CSF leak and how does it happen?
Cerebrospinal Fluid, typically known as CSF, is the cushioning liquid that fills the space between your brain and the encasing layer of tissue know as the dura. The dura and the bone that separates it from the sinuses can develop a breach that allows fluid to leak into the sinuses and emerge as a clear drainage from the nose or ear, or a flow of salty-tasting liquid in the throat. The causes of such a break, with its consequent leakage, can be from a traumatic head injury, or as an after-effect of brain or sinus tumor surgery, or from medical conditions that cause increased pressure in the CSF. Females aged between 20 and 45 are at higher risk for this relatively rare condition. Elevated CSF pressure is associated with obesity, and the rise in obesity rates in the population could be responsible for more reported cases of CSF leaks.
What are the symptoms of CSF leak?
- A persistent runny nose, especially in just one nostril, that does not clear up
- Salty-tasting discharge in the throat
- Clear fluid leaking from one ear
- A persistent headache or vision changes
If you have persistent symptoms like these, consider seeing a doctor to help determine the cause. The doctor may examine your nose with an endoscope, and may also ask you to lean forward to see if the drainage of fluid increases.
What happens during a CSF leak surgical procedure?
Once the province of neurosurgeons who operate from the brain side of the skull base, today CSF leak repair is often performed endoscopically from the sinus side. In many cases this can be performed on an outpatient basis by an ENT surgeon.
If pre-operative images show that the defect site is clear, the surgeon will open up those sinuses and remove bone that may obstruct the view of the defect site. The surgeon inserts a small endoscope through the nostril into the nasal cavity, which permits direct visualization of the site and the repairs made by the surgeon.
Once the CSF leak site is identified, a small section of the mucosal tissue that lines the area is removed to expose the bony defect. Graft material is placed over the hole in the skull base, and sometimes secured with surgical adhesive. Once the surgeon is sure the CSF leak is stopped, various sealants or packing may be used to further support the repair site. The surgeon may use packing in the nasal passage, which will be removed within few days.
A lumbar drain may be used for a period after surgery to minimize pressure on the repair site. In some cases, the doctor will recommend bed rest for up to a few days after the repair, along with medications to minimize brain fluid pressure.
What are the risks of a CSF leak surgical procedure?
The risk of the surgery is basically similar to risk of common endoscopic sinus surgery. The risk of unexpected damage to nearby organs including the brain and optic nerve is low, less than 1%. Although it is possible that the leak can come back, the success rate for this procedure is above 90%.
What are the benefits of a CSF leak surgical procedure?
Besides stopping the CSF leak, this procedure reduces the risk of an intracranial infection if bacteria (commonly found within the sinuses) were to infect the brain and its surrounding tissue.