Middle Ear and Mastoid Microsurgery1. Myringotomy

Myringotomy is usually performed in the anterior quadrants, around theregion of the light reflex. A cut is made with a myringotomy. knife in a radial orientation. Avoid making an incision in the posterosuperior quadrant so as not to damage the ossicular chain. If the anterior wall isprotruded, the myringotomy can be placed just inferior to the umbo. After myringotomy, the middle ear effusion is aspirated and a ventilation tube inserted. Local anesthesia is usually sufficient for inserting a ventilation tube. General anesthesia is required in infants and overly active children.

a small myringotomy is performed in the anterosuperior quadrant, in a radial

orientation.

The knife is cutting the tympanic membrane. Middle ear effusion retained

in the tympanic cavity is coming out

The myringotomy is complete. Middle ear effusion is evacuated with

a fine suction tube.

When the middle ear needs to be ventilated for a long period, we

use a silicone T-tube.

The flanges of the tube are held with microforceps.

The tube is held firmly with the forceps, until the tips of the flanges

are inserted into the tympanic cavity through the myringotomy.

The tube is in place.

General Otosurgical Procedures• Retroauricular Skin Incision

To allow maximum flexion of the auricle,the retroauricular incision is planned in such way

that the incision covers 180° of the external auditory canal.

Before incising the skin, a few hatch marks are made. The incision line is about 0.5 cm posterior to the attachment of the auricle (retroauricularcrease). The skin incision should be perpendicular to the surface, ending within the subcutaneous layer.

The cut allows the surgeon to fold theauricle forward fully for good vision of a wide

operating field.

With an electrocautery, the cut is advanced anteriorly toward the external auditory canal, preserving the underlying connective-tissue layers. The anterior limit of dissection is the perichondrium of the cartilage of the external auditory canal. For the following graft take, the area of the temporal muscle is widely exposed. Note the angle of the electrocautery for carrying out the dissection anteriorly, parallel to the temporalis fascia.

Harvesting Grafting Material

•The temporalis fascia is very frequently used as a source of autologous grafting material since the fascia is large enough for tissue to be harvested from the retroauricular incision.Temporalis Fascia

(Retroauricular ScarTissue)

•Tragal cartilage and its perichondrium are used in reconstruction of the tympanic membrane in the transcanal approach, and may be used in reconstruction of the atelectatic tympanic membrane in the retroauricular approach.

Tragal Cartilage and Perichondrium

•When it turns out that skin grafting is required, we prefer to harvest grafting material from the edge of the incision to avoid making another wound. In accord with our strategy for the surgical approach, the graft is taken at the retroauricular incision in most cases

Split-thickness Skin Graft

Temporalis Fascia (Retroauricular Scar Tissue)

After completing the retroauricular incision, a small shallowcut is made in the subcutaneous tissue upon the temporalismuscle. Using the index finger, the cut is enlarged and a plane between the temporalis fascia and the subcutaneous tissue is established. A sufficiently wide area of the fascia is detached from the skin.

A self-retaining retractor is applied to expose this area. Formaximum exposure, the other retractor is applied to the superior edge and held by the scrub nurse

The temporalis fascia is composed of the superficial and the deep layers. In most cases, only the superficial layer is resected, and the deep layer is left intact in case revision surgery is required.

Temporalis Fascia (Retroauricular Scar Tissue)

The harvested fascia is placed on a special instrument with Gelfoam on the other face.

The fascia is compressed together with Gelfoam and left for several minutes.

The fascia is detached from the Gelfoam and placed on a wooden tongue depressor.

To facilitate trimming and placement, the fascia is dried on the tongue depressor until it is used. Illumination by a satellite operating lamp or any incandescent lamp facilitates drying of the fascia

Tragal Cartilage and Perichondrium

The area is anesthetized before thecartilage is taken.

A small straight cut is made on the posterior surface of the tragus near the tip.

Subcutaneous tissue is dissected and cartilage of the appropriate size for reconstruction isexposed.

Tragal Cartilage and Perichondrium

The cartilage is taken out.

The wound does not require suturing. Alignment of the edges of the wound followed by packing of the meatus with Gelfoam at the end of the surgery is sufficient.

On a wooden tongue depressor, the perichondrium is detached from the cartilage with a Lempert periosteum elevator.

Tragal Cartilage and Perichondrium

Perichondrium is detached from one of the surfaces. The connection between perichondrium and cartilage is preserved at the tip.

The perichondrium is detached from the contralateral side of the cartilage.

A piece of tragal cartilage and a large piece of perichondrium are harvested.

Split-thickness Skin GraftWhen it turns out that skin grafting is required, we prefer to harvest grafting material from the edge of the incision to avoid making another wound. In accord with our strategy for the surgical approach, the graft is taken at the retroauricular incision in most cases

The area from which the skin graft is to be taken is planned on the posterosuperior border of the retroauricular incision. A thin skin layer is cut with a large-blade scalpel. The area where the skin has been taken away is seen.

Split-thickness Skin Graft

A strip of skin about 5mmin width is resected from the posterior edge of the retroauricular incision with a new scalpel blade. The skin is immediately placed on a wooden tongue depressor with the epidermal surface downward, since determination of which side is which may become very difficult after a while

The skin is thinned as much as possible using a scalpel with a new blade

Incision of the External Auditory Canal

• Myringoplasty and Canal Wall Up Tympanoplasty

• Canal Wall Down Tympanoplasty and Ossiculoplasty

Rules for the Posterior Meatal

Skin Incision

• Under Direct Vision• Under the MicroscopeSurgical Steps

Under Direct VisionA self-retaining retractor is applied to theretroauricular incision. The musculoperiosteal flap is cut with an electrocautery. An anteriorly-based flap is created by two cuts posterior to the external auditory canal. One cut along the linea temporalis joins the other cut from the inferior edge of the external auditory canal.

The flap is detached from bone using aperiosteum elevator.

The musculoperiosteal layer has been detached from the bone. For mastoid surgery, the other self-retaining retractor is applied to expose the surface of the mastoid sufficiently.

Right Ear

The posterior meatal skin is incised circumferentially with a Beaver blade, close to the annulus.

A longitudinal cut is made medially to laterally in the superior wall, to join the circumferential incision.

Another similar cut is made in the inferior wall.

The procedure makes a laterally based posterior meatal skin flap, and the meatus can be opened posteriorly.

The posterior meatal skin flap, together with the auricle, is held by a retractor. Since the meatus is narrow and access to the tympanic membrane is limited due to the bony protrusion in the anterior wall, the anterior skin is also cut laterally and partially detached for canalplasty.