Fig. 64A
Ear speculum

The ear speculum is introduced and kept in place with the left hand.

Fig. 64B
Myringotomy

Fig. 64C
Transportation of the ventilating tube

Many kinds and shapes of ventilating tubes are available. If no commercially manufactured tubes are available, it is possible to obtain “home-made” polyethylene tubes of various sizes (PE 50, PE 60). The flanges of the tubes are created by placing the cut end of the tubes over a hot metal surface. The tubes are sterilized prior to use. The tube is picked up using a 1.5-mm, 45° hook and placed in Ringer’s solution. The alternative to the hook is to use a large straight alligator forceps to pick up and transport the ventilating tube. A wet ventilating tube is less prone to sliding away along the tympanic membrane during placement.

Fig. 64D
Transportation of the ventilating tube (cont.)

The ear speculum is kept in position with the left hand, and the ventilating tube is introduced into the EAC with the right hand.

Fig. 64E
Ventilating tube on the tympanic membrane

The tube is placed on the tympanic membrane close to the myringotomy opening.

Fig. 64F
Introduction of the ventilating tube

The 1.5-mm, 45° hook (29-I) is used to place the inner flange of the tube over the myringotomy incision.

Fig. 64G
Introduction of the ventilating tube (cont.)

The inner flange of the tube is rotated into the tympanic cavity using the 1.5-mm, 45° hook.

Permanent Ventilating T-Tube (Grommet)

Surgical Technique

For permanent ventilation our preference is a Goode T-Grommet, Xomed Product No. 40812. This tube remains in place for up to 3 years. Thereafter, a chronic perforation of the tympanic membrane may result in 10% of the cases.

Fig. 65
Permanent ventilating T-tube

a Goode T-grommet silicon ventilating tube.

b The flanges of the tube are grasped with a large smooth alligator forceps (45-I).

c Trimming the flanges of the T-grommet.

d Modified T-grommet ready for introduction.

e Myringotomy in the anteroinferior quadrant of the drum.

f The flanges of the T-ventilating tube are grasped with a small smooth alligator forceps (44-I) and inserted through the myringotomy incision.

g Final position of the T-ventilating tube.

Temporary access to the round window may be required for the application of drugs to the middle ear and round window niche. This approach was also used in the beginning of the cochlear implant era for introduction of temporary round window electrodes. This application will be used to demonstrate the surgical steps of the procedure.

Surgical Technique

A temporary round window electrode is used to test whether a patient with bilateral deafness is suitable for a cochlear implant.

Fig. 66A
Endaural skin incision

The helicotragal incision is carried out as for stapedotomy.

Fig. 66B
Tympanomeatal flap

The posterior limbs of the tympanomeatal flap are carried out more caudal than for stapes surgery.

Fig. 66C
Exposure of the round window

The tympanomeatal flap is elevated and the chorda tympani dissected free. The round window niche is exposed below the chorda.

Fig. 66D
Electrode notch drilled in the posterior canal wall

Fig. 66E
Insertion and fixation of the electrode

The ball end of the insulated platinum iridium electrode is applied on the round window membrane. If necessary, the electrode is fixed in the notch of the posterior canal wall with a drop of Histoacryl glue.

Fig. 66F
Threading of the electrode through the posterior canal wall

The posterior end of a large injection needle is cut away with strong scissors to allow passage of the electrode. The injection needle is introduced from the retroauricular skin into the lumen of the EAC. The lateral end of the electrode is passed through the needle and brought out behind the pinna.

Fig. 66G
Retroauricular fixation of the round window electrode

Steristrips are used to fix the electrode in the retroauricular region. The electrode remains in place for 2 days. After testing, the electrode is removed by pulling it through the skin. Care must be taken to use a very small amount of glue to fix the electrode to the notch in the posterior canal wall to avoid pain when removing it.

Surgical Technique

Indication. Retention of cerumen and keratin in the external canal with recurrent episodes of external otitis.

Surgical Principle. Removal of external canal exostoses requires complete elimination of overhanging bone lateral to the tympanic annulus. The shape of the bony external canal should be an inverted, truncated cone. The meatal skin flaps should be kept intact to promote rapid reepithelization of the enlarged canal. To keep the canal skin intact, the posterior bony overhang should be removed first and the anterior second.

Fig. 67
Principles of canalplasty for exostosis

a Preoperative view showing narrowing of the canal due to the exostosis.

b Elevation of posterior, medially based meatal skin flap and removal of posterior exostosis.

c Elevation of anterior meatal skin flaps. This includes a longer, laterally based and a smaller, medially based flap. Elevation of these flaps allows the removal of anterior exostotic bone.

d Completed canalplasty.

Fig. 68A
Skin incision

Fig. 68B
Posterior meatal incision

The entrance of the EAC is enlarged with two Fisch endaural retractors (see Instrumentation). A posterior semicircumferential incision (A–B) is carried out along the lateral edge of the exostotic bone. The broken line indicating the incision in the figure is not placed correctly and should be advanced to the edge of the exostosis. This will shorten the posterior meatal flap, allowing better visualization of the posterior exostosis.

Fig. 68C
Elevation of the posterior meatal flap

Fig. 68D
Removal of posterior exostosis

a