Mastoidectomy

C. Posterior Tympanotomy and Combined Approach tympanoplasty. (C.A.T.) Mastoidectomy with preservation of the posterior wall of the external ear canal-Air containing mastoidectomy techniques.

Magnification the cholesteatoma metrix is completely removed is an intact sac (not piecemeal).

The Cholesteatoma is after all an epithelial cyst involving the mastoid. If you can excise a cyst in toto, it is not necessary to exteriorize it. With modern techniques it is possible to excise it totally and perfectly so you do not have to exteriorize the mastoid cavity. After this operation, you get an endothelium-lined air containing closed mastoid cavity as in normal ears. The air containing cavity is a reservoir to guard against Eustachian catarrh and the hearing result is, therefore, not liable to be affected by a cold. However the technique requires a very high order of skill and a lot of painstaking effort. Under high at the same time preserving a thin posterior meatal wall. Arrangements are also made for mastoid aeration using cartilage and silastic sheet to maintain the path of aeration. Unless done perfectly there is a risk of residual or recurrent cholesteatoma. In case of doubtful clearance a second look may be required. In case of a huge invasive cholesteatoma (difficult pathology) or difficult anatomy (low dura or forward lateral sinus) a C. A. T. may be difficult. Instead of struggling in a difficult situation it is better to take down the bridge & reconstruct it. In case of doubtful clearance a second look may be required.

Complete clearance of the disease is easy because of good visualization obtained by lowering the posterior canal wall. I have my own technique using fascia supported by cartilage struts. Silastic sheeting is used to maintain aeration. Combining a tympanoplasty with ossiculoplasty restores hearing.

b. Minimum postoperative care no cavity problems make it ideal for patients coming from long distance.

Advantages of posterior canal wall reconstruction with cartilage :

•  Complete clearance of disease is easy because of good visualization obtained by lowering the bony posterior canal wall.

•  The Reconstructed posterior canal wall is a thin membrane so there is no risk of a retraction pocket (recurrent cholesteatoma) & no risk of a residual cholesteatoma growing undetected as in a C.A.T. In case if for any reasons the path of aeration were to fail, the thin, membranous posterior canal wall would retract outwards & line the cavity.

•  Residual endothelium is aerated down the Eustachian tube.

4. Normal anatomy is simulated; this is ideal for pilots and divers, who are able to carry out their professions.

5. An adequate reservoir of air is preserved in the middle ear & mastoid, and this maintains the hearing result even in spite of recurrent upper respiratory infections.

6. One stage healing-Both hearing restoration & clearance of disease are achieved in one operation which is important in our country, where financial & social restrictions as well as poor travel facilities prevent frequent follow up visits for open carities & second look operation for C.A.T.

(7) In Deaf and discharging mastoid Cavities previously operated upon by old techniques of Radical and Modified Radical Mastoidectomy a one stage healing is achieved.