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[Endoscopic anatomy study of jugular foramen region].

OBJECTIVE
To observe anatomic structure of jugular foramen region by endoscope, to provide anatomic data for avoiding damnification in the surgery.


METHOD
We performed the retrolabyrinthine and retrosigmoid endoscopic surgery on 8 fomalin-fixed adult cadaver specimens and observed the structures of jugular foramen by endoscope and compared the different surgeries at the same time. We excised the calvarium and cereburm and exposured and observed the nerves and vessels. Moreover we measured the the distance from internal accoustic pore to glossopharyngeal and analyse the data by SPSS.


RESULT
All retrolabyrinthine endoscopic surgeries were performed successfully. Only 4 postsigmoid endoscopic surgeries were performed without damage of cerebellum which is the major obstacles. The distance from internal accoustic pore to glossopharyngeal was(8.26 ± 1.05) mm. About half of posterior inferior cerebellar arteries located to inboard of nerves.


CONCLUSION
The jugular foramen region endoscopic surgery can be performed successfully by retrolabyrinthine. The "lockhole" technology by retrosigmoid is more difficult for blocking of cerebella. The internal acoustic porus is a fixed structure of the cerebellopontine angleand a perfect landmark to the surgery.