2. Etiology
A.Trauma-most common cause.May be either accidental or surgical.
1.Endoscopic sinus surgery
2.Trans sphenoidal hypophysectomy
3.nasal polypectomy
4.Skull base surgery
B.INFLAMMATIONS-
1.mucoceles of sinuses
3. 2.sinunasal polyposis
3.Fungal infection of sinuses
4.Osteomyelitis
C.NEOPLASMs-benign or malignant invading skull base
7. Diagnosis of CSF rhinorrhea
1.History of clear watery discharge from nose on bending head or straining.
2.may be seen on rising in morning when the pt bends his head-fluid which had
collected in the sinuses ,particularly splenoid sinus empty into the nose-Reservoir
sign
3.Double target sign-Csf rhinorrhea after head trauma is mixed with blood shows
this sign when collected on a piece of filter paper I.e.centarl red spot and
peripheral lighter halo.
8. 2.Diagnostic nasal endoscopy –to localize site of leak
3.Laboratory tests-
A.Beta-2-Transferrin-seen in CSF, not in nasal discharge ,it’s presence is specific
and sensitive.Perilymph and aqueous are the only other fluids contain this protein.
B.Beta trace protein-also specific for CSF ,secreted by meringues and choroid
plexus.
9. Localization of site
1.HRCT-coronal and axial section of brain
2.CT cisternogram-intrathecal iohexol +CT scan
3.MRI-T2 weighted image .It requires active csf leak at time of scan.
4.Intrathecal fluorescein study-0.25-0.5ml of 5% fluorescein dye injected.Pt lies in
10 degree head down position for some time.Dye appears green when seen with
blue filter.
10. Treatment
A.CONSERVATIVE MEASURES
1.BED REST
2.ELEVATION OF HEAD OF BED
3.STOOL SOFTNERS
4.AVOIDING NOSE BLOWING,SNEEZING AND STRAINING
B.prophylactic antibiotics to prevent meningitis
C.Lumber drainage to reduce csf pressure
11. Surgical repair
A.NEUROSURGICAL INTRACRANIAL APPROACH
B.EXTRADURAL APPROACHES
1.EXTERNAL ETHMOIDECTOMY FOR CRIBRIFORM PLATE AND ETHMOID AREA
2.TRANS SEPTAL APPROACH FOR SPHENOID
3.OSTEOPLASTIC FLAP APPROACH FOR FRONTAL SINUS LEAK
12. C.TRANSNASAL ENDOSCOPIC APPROACH
Most of the leak from anterior cranial fossa and sphenoid sinus can be managed
endoscopically
Hadad-Bassagasteguy flap-for anterior skull base defect reconstreconstruction.
Vascular pedicled Mucosal flap of nasal septum mucoperichondrium and
mucoperiosteum based on NASOSEPTAL ARTERY
(Posterior septal artery).
13. Principle of reconstruction
1.Define the site of leak
2.preparation of graft site
3.Underlay grafting of fascia extradurally followed by placement of mucosa
4.If bony defect >2cm ,it is repaired with cartilage
5.placement of surgicel and gelfoam further strengthens area.
Fascia-fascia Lata or temporalis fascia.Sometimes fat from abdomen or thigh can
be used to plug defect in place of fascia.
