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Extended posterior tympanotomy: is done by further extension of the posterior tympanotomy superiorly (by removal of the incus buttress), or inferiorly (by cutting the chorda tympani) which may be required to expose the sinus tympani.
Step 2 : Proper Extirpation of Pathology
Cholesteatoma is primarily a middle ear disease with possible extension to other areas of the temporal bone or its surrounding structures. Proper clinioradiological staging of the disease is necessary to outline a road map for the surgical treatment. Belal (2005) have proposed the TMC staging system of cholesteatoma . The stage of the disease determines whether mastoidectomy is necessary , and whether open or closed technique should be done. In all the cases, proper anterior exposure of the middle ear should be done for proper visualization (microscopic and endoscopic) and identification of the middle ear anatomical structures including the ossicles,facial nerve, round window, eustachian tube orifice, tensor tympanic tendon and cochleariform process, pyramidal eminance and stapedius tendon, hypotympanic cell tract, and middle ear folds and recesses.
Step 3 : proper restoration of function
Restoration of middle ear function includes reconstruction of the attic, tympano- ossicular reconstruction, and reconstruction of the middle ear space. Reconstruction of the attic wall to usually done by a semilunar piece of autogenous tragal or conchal cartilage and is meant to prevent post-operative retraction of the graft. Bone cement has been used for the same purpose.
Tympano-ossicular reconstruction is usually done in the same stage using autograft ossicles, fascia or perichondrium. Periosteum may be used in revision cases . The use of autogenous ossicles in cases of cholesteatoma is controversial, but the use of prostheses in primary operations is not advised due to the high rate of extrusion since graft healing in these cases is not stable. Aeration of the middle ear is usually done by lateralizing the handle of the malleus, repositioning of malleus with section of tense tympani tendon to put it in alignment with the stapes to facilitate ossicular reconstruction. Atelectatic parts of the eardrum are removed. The use of thick silastic sheets in the middle ear is only done if excessive removal of mucous membrane is done to remove polypi or granulations.
The mean follow-up period was 42 months (range 12-72 months). Of the 120 procedures, all the cases had anterior tympanotomy, 114 cases had atticotomy, 95 had intact canal wall (ICW) mastoidectomy and 13 had open mastoidectomy. In 10 cases no mastoidectomy was required. Table 2 summaries the surgical procedures performed in the present series.