CSF rhinorrhea is defined as abnormal leakage of cerebrospinal fluid through the nasal cavity after the break in the barriers separating the nasal cavity from the subarachnoid space.CSF rhinorrhea is an important clinical entity as it can lead to serious complication and in some cases mortality. The prompt clinical diagnosis is important
Clinical Presentation :
Patients of CSF rhinorrhea presents with Unilateral watery discharge (90%) with salt or sweet taste in the throat. Rhinorrhea is positional with increase in leaning forward or standing position some times referred to as Tea Pot sign.
Other symtoms include headache, decrease in vision and sometimes dizziness and tinnitus,
Diagnostic test:
Beta 2 Transferrrin : beta-2 transferrin is a glycoprotein that is present in CSF, but is not detected in nasal secretions or surrounding tissue. It is used as a marker for CSF rhinorrhea. It is detected by using immunofixation , sodium dodecyl sulphate polyacrylamide gel electrophoresis, and isoelectric phoresis. It has high sensitivity and high specificity. Beta 2 transferrin is also present in Vitrous and perilymph(7,11).
Beta Trace proteins : Similar to beta-2 transferrin beta trace protein is also present in high concentration in csf , it is produced by leptomeninges and choroid plexus. The reported sensitivity and specificity of the test is 100 percent. Bacterial meningitis and renal insufficiency can affect the level of beta trace proteins in csf.
Imaging :
High Resolution Computed Tomography (HRCT):
HRCT is first choice for localization of site of leak. It is best modality to delineate the osseous anatomy for surgical planning. If patient has multiple osseous defects than it becomes challenging to determine which defect is definite source of csf leak. If only 1 osseous defect is identified and corresponds to clinical symptoms than no additional further imaging is needed to proceed surgery.
Computed Tomography Cisternography(9):
CTC is performed by instilling intrathecal non ionic myelographic iodinated contrast (fluoroscein). Sinuses are scanned both in prone and supine position. There is increase in > 50 Hounsfield units around the osseous defect in positive study around site of leak.
MRI sinuses :
Magnetic resonance imaging (MRI) is a useful adjunct in the evaluation of patients with CSF rhinorrhea. Patients with spontaneous CSF leaks have the highest rate of meningoencephalocele formation, ranging from 50% to 100%.1,11 MRI is effective in assessing the contents of meningoencephalocele. Another benefit of MRI in the evaluation of patients with spontaneous CSF leaks is the recognition of the empty sella. Empty sella syndrome is a common radiographic finding seen in both spontaneous CSF leaks and Intracranial hypertension
Management :
Traumatic CSF rhinorrhea:
Approximately 80% of CSF leaks result from nonsurgical trauma, 16% from surgical procedures and the remaining 4% are nontraumatic. Of the traumatic leaks, more than 50% are evident within the first 2 days, 70% within the first week, and almost all present within the first 3 months
Conservative management:
Conservative treatment consists of strict bed rest and elevation of the head at least 30_. In addition, patients should be advised to refrain from coughing, sneezing, nose blowing, and straining or Valsalva maneuvers. Stool softeners are recommended, as well as antiemetics to avoid emesis or retching, antitussives to avoid coughing, and strict blood pressure management. The goal of these measures is to reduce active flow through the leak, reduce CSF pressure, and allow healing of the defect to seal the leak, avoiding surgical intervention
Cerebrospinal Fluid Diversion
If there is persistence of the leak with conservative treatment, CSF diversion (most commonly with a lumber drain but occasionally serial lumbar punctures) is pursued. Lumbar drains are passive devices yet they require active management,. Average drainage rates are around 10 mL per hour. Optimal drainage lowers CSF pressure to decompress the leak; however, if drainage is too high severe headaches and pneumocephalus may result from drawing of air through the skull base defect into the cranial vault. There is also the added risk of meningitis. The benefits are that the addition of CSF diversion to conservative measures raises success rates to 70% to 90% with the average duration of drainage being 6.5 days
Surgical management:
Open intracranial approaches have historically been used for CSF leak repair, but in recent decades these have largely been replaced by endonasal endoscopic approaches, given their high success rate and lower morbidity profile. Commonly utilized endoscopic repair techniques for CSF leak are numerous, including free tissue grafts, vascularized flaps, and tissue sealants, as well as various multilayer combinations of these methods
Endoscopic repair
There are a variety of different graft materials available for endoscopic repair of CSF leaks, including fat, bone, allografts, free mucosal grafts, and vascularized grafts, as well as glues or sealants to secure these materials in place. Following an extensive literature search on the topic of endoscopic repair for CSF rhinorrhea, the overall success rate ranges from 70% to 100% on first attempt and 86% to 100% on second for all reported repair materials. Endoscopic techniques have emerged as the preferred approach to the repair of skull base defects since their initial description by Wigand in 1981. This initial report described repair of a defect encountered during sinus surgery. In 1989 the first report of the use of rigid trans nasal endoscopy for the endonasal repair of CSF rhinorrhea was described, Following identification and localization of the skull base defect, standard endoscopic techniques are used to expose the defect site. This approach provides excellent exposure of the ethmoid roof, cribriform plate, and the sphenoid sinus.
Pre Op preparation :
- Complete blood workup
- Preparation of Thigh and abdomen for taking fat and fascia lata graft
- you will be started on prophylactic antibiotics before surgery
- you will be explained that you may need lumbar drain to decrease the csf pressure post surgery for 5 to 6 days
- there will be nasal pack for atleast 5 days
- the surgery is done as combined procedure along with neurosurgery team
Complications of surgery
Complications are rare through endoscopic approach, possible complications includes
- Anosmia ; there may be decrease or complete loss of smell post surgery
- Meningitis
- Intracranial haemorrhage
- Failure of repair or recurrence
- Need for revision surgery
- Need for transcranial approach if endoscopic approach fails or there are multiple leaks
Post op instructions:
- strict bed rest for 2 weeks
- no heavy exercises or lifting of the weight for 6 weeks
- Avoid straining , couging, sneezing
- avoid going to outdoors or crowded places as there is high chances of getting meningitis if you develop any nasal infection
- avoid blowing of the nose
- report to the emergency if you develop headache with fever or nasal bleeding