Intrathecal dyes combined with endoscopic techniques
Historically used dyes are:
Messerklinger combined intrathecal fluoreceins in mixed c 10 ml of CFS from a routine lumbar puncture.
This mixture is introduce via a polymed point spinal needle and the patient is placed in the Tredelenberg position for approximately 1 hours.
The nose is spread with a topical anaesthetic and vasoconstrictior (4% lignocaine c 1:1000 Adrenaline) and the endoscopic examination can begin after a minute using a 4mm 30º endoscope .
Positive if flurescein can been seen coming from the defect.
Use blue filter increase the ease of detection(+ve : up to 1:10 million dilution)
If CSF leak into the nasopharynx from the ET orifice specially during swallowing → lateral skull bad
If negative Place merocel sponges in the none for 6 hours and examine ↓blue light.
complication are (usually due to higher those than recommended)
previous spinal surgery.