This demonstrates the anatomic relationship of the normal ossicular chain. When it is disrupted, a severe conductive hearing loss results. Surgery is aimed at reestablishing the continuity of the conductive mechanism from the tympanic membrane to the oval window. This may require an interposition graft or prosthesis. This can generally be accomplished by lifting the tympanic membrane via a transcanal or other approach of the surgeon’s preference.
A detailed description is beyond the scope of AOCMF Surgery Reference.
Some surgeons will use a lumbar drain to keep the CSF pressure low. If this is used great care must be exercised to ensure that excessive drainage of CSF does not occur inadvertently. Normally, not more than 240 ml/day should be drained. Stool softeners should be given to minimize straining. The head of the bed should be elevated.