Canal Wall Down Surgery

in “Canal Wall Down Surgery” for squamosal CSOM, You said we remove the facial ridge … but in that area . Also lies the chorda tympani N. And fossa incudis !! So do we remove these 2 also ?

Also while removing the common wall in this procedure only … What happens to the tympanic membrane ??

CWD procedure is done for extensive cholesteatoma. For lowering the ridge , always the chorda tympani has to be sacrificed and fossa incudis also goes with the wall. The TM part involved with the cholesteatoma is also excised.

All this is reconstructed by tympanoplasty at the end .