Combined approach tympanoplasty (CAT) or canal wall up (CWU) mastoidectomy is a surgical procedure performed for the removal of a cholesteatoma in which the wall of the ear canal is left intact.
Cholesteatoma is an abnormal growth of skin in the middle ear behind the eardrum. Layers of old skin build up inside the ear to form a pocket which overtime increases in size and damages the ossicles of the middle ear. The ossicles refer to the tiny bones which transmit and amplify external sound to the inner ear. Enlargement of this pocket may cause; hearing loss, recurrent infection, foul smelling discharge, balance disturbance and facial paralysis.
The aim of this procedure is to remove the cholesteatoma, prevent future complications and spread of infection to other structures, and to leave the canal wall intact.
Combined approach tympanoplasty involves removal of the mastoid air-cells while retaining the bony walls of the ear canal intact. Surgery is performed under the effect of general anaesthesia.
The operative steps include:
Incision behind the ear, removal of mastoid bone, elevate the eardrum, posterior tympanotomy (entry into the middle ear from behind via the mastoid, removal of cholesteatoma, restoration of hearing with titanium prosthesis and closure of the wound.
A second look procedure may be required after 12 months to evaluate for residual or recurrent cholesteatoma.