Stapedotomy

This operation is an extremely delicate microsurgical operation which is performed under high power magnification through the ear canal under local anesthesia. There are many variations to this procedure, and the surgeon should be conversant with all of them in order to customize the surgery to the patient, thus able to offer the patient what is best in his or her particular situation.

TECHNIQUES USED FOR SURGERY

1. The Direct Piston Technique (Fig.-A)

The eardrum is turned forward and the immobile stapes removed using instruments, a drill, or a laser.

A 0.7 mm hole is made in the footplate and a 0.6 mm diameter Teflon—or titanium piston is inserted connecting the incus to the hole. The eardrum is then replaced to its normal position.

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The Teflon piston-is self lubricating and it does not adhere to the body tissues, so continued growth of the Otosclerotic focus on the foot-plate cannot fix itself to the side of piston and prevent vibration.

It is essential that the diameter of the hole and the length of the piston should be accurate to within 1/8 of a mm. If the piston has been cut too short, the Otosclerotic focus can grow underneath the piston and cause late conductive deafness. If it has been cut too long or if the hole is made too big, late nerve deafness due to leakage of inner ear fluid may occur (Perilymph Fistula).

2. The Piston with Vein interposition Technique (Fig.-B)

A 0.8 mm hole is made in the footplate covered with a vein graft and a 0.4 mm diameter piston is used to connect the vein-graft to the Incus. The advantage of this is the formation of an immediate and durable oval window seal so the inner ear fluids cannot leak out.

3. Posterior-Crus on Perichondrium Technique (Fig.-C)

The entire footplate is removed from the oval-window, which is then covered with perichon­drium and the Posterior crus of the stapes is used to connect the Incus to the Oval-window. The problem of late nerve deafness due to a long piston can never arise in this technique because the patient's own posterior crus can never be too long. However very active Otosclerosis may invade and ossify the Perichondrium causing late conductive deafness. if this should happen it is still possible to use the piston.

4. Cartilage on Vein Technique (Fig.-D)

The Tragal-cartilage is used instead of the Posterior ­crus to connect the Incus to the Vein covering the Oval-window.

All these techniques have their own advantages and disadvantages. A good stapes-surgeon should be able to use all these techniques with equal ease. In order to get all the advantages of the various techniques it is advisable to use one technique on the first ear and another technique on the second ear.

In our clinic, we prefer to use the Teflon piston with vein interposition technique as the method of choice, as it has the maximum margin of safety as well as the best hearing results.

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