inner ear fenestration

Inner ear fenestration is the earliest surgical method used to treat otosclerosis. In the bony semicircular canal, a small window is opened, closed with the eardrum tympanic membrane flap, and the new window replaces the vestibular window of the lesion, so that the sound wave is diverted into the inner ear. This operation loses the sound reinforcement of the tympanic membrane and the ossicular chain, and the best effect gas The hearing loss is 30dB, and an open mastoid cavity is left. There are a series of problems such as regular cleaning. This technique is less used after the operation of the humerus surgery, but the operation is still not completed when the vestibular window closure and the humerus surgery cannot be completed. Has its practical value. Treatment of diseases: otosclerosis Indication 1. Facial nerve deformity, the most common is the horizontal section drooping, blocking the vestibular window. 2. The residual iliac artery of the foot plate. 3. The vestibular window hardening stove is a wide or closed foot plate. 4. Congenital vestibular windows are absent. Contraindications 1. External auditory canal inflammation, perforation of the tympanic membrane, dysfunction of the eustachian tube, acute inflammation of the nasal cavity and nasopharynx, and surgery after treatment. 2. There are cardiovascular diseases, malnutrition, chronic infectious diseases such as tuberculosis and hepatitis, endocrine system diseases, to be cured or stable after surgery. 3. The lesions develop rapidly, and severe sensorineural hearing loss has been shown. The air-bone conduction difference is within 10~15dB, which is not suitable for surgery. 4. Patients under the age of 10 and over 80 years of age are treated as appropriate. 5. Women should not undergo sacral surgery during menstruation. Preoperative preparation 1. Ear 3d with 4% boric acid before surgery. 2. 1d before surgery, the hair around the ear is about 3 ~ 4mm hair, clean the external auditory canal with 75% ethanol, put the sterile cotton ball in the external auditory canal or wrap with sterile dressing. 3. Low-pressure enema one night before surgery, the mentally ill sedative phenobarbital (luminal) 0.09g or diazepam (diazepam) 5mg. 4. Local anesthesia or general anesthesia, fasting and water-free in the morning. 5. Take phenobarbital 0.09g half an hour before surgery, and underwent subcutaneous injection of atropine sulfate 0.5mg. 6. Intramuscular injection of penicillin 800,000 U, 2 / d before surgery. Surgical procedure 1. Incision fenestration can be performed through the ear and incision in the ear. According to the small characteristics of the adult external auditory canal in China, the Lempert incision is slightly moved outward to the mastoid radical incision. Take the left ear as an example. Cut at 12 o'clock on the upper wall of the external auditory canal, make an arc-shaped incision along the leading edge of the cartilage of the ear to the 6th point of the lower wall, and reach the first incision as deep as the bone garment, and then start from the first incision at the foot and ear of the ear Between the screens along the front edge of the rim of the ear, a curved tangential length of about 1.5 to 2.0 cm is made as the second slit. 2. Excision of the subcutaneous soft tissue of the cartilage of the ear canal, and then cutting the bone coat, peeling the bone coat upwards, backwards and downwards with the periosteal stripper, exposing the papillary cortex and the upper ear canal, and seeing the mastoid sieve area . When making incisions and exposing the mastoid bone, try to avoid damage to the diaphragm to reduce the chance of bleeding. Do not peel off the external ear canal skin first, so as to prevent the bone cuttings or broken bone pieces from being cut by the electric drill to the periosteal surface of the skin. The flaps of the cover window remain broken and the new window is closed. 3. Open the sinus sinus with a perforated drill bit drilled into the sinus sinus from the upper and lower screen area of the ear canal. After finding the sinus sinus, expand the mastoid cavity and open the upper tympanic cavity forward, and expose the anvil and the hammer bone. The purpose of grinding the mastoid cavity is to fully expose the outer semicircular canal to facilitate window opening. The gas room around the labyrinth can be removed with a curette or a diamond bit to "contour" the outer semicircular canal and the posterior semicircular canal, and then the upper posterior wall of the external auditory canal is ground into a thin bone piece from the side of the mastoid cavity. Fully exposed, and the anvil joint and its upper ligament are visible. 4. Remove the anvil and the hammer bone. Use a narrow and flat small stripper to gently peel off the outer ear canal and then the upper wall of the skin to the drum ring. Keep the connection between the skin and the tympanic membrane in the peeling and make it intact. When the upper and lower bone fragments of the external auditory canal are removed by a flat and slender bone clamp or an electric drill, the outer ear canal flap of the tympanic membrane is easily damaged and must be protected with a vaseline oil gauze. After the bridge is removed, the upper tympanic cavity is exposed, and the hammer bone, the anvil bone and the drum are visible. The anterior and posterior arches and the low-faced neural crest should be removed, down to the drum ring plane, that is, after the facial nerve is protected to a minimum, the anvil and the anvil joint are separated, the anvil is taken out, the hammer bone is cut and the hammer neck is removed, and the hammer bone is removed to make the tympanic membrane The external auditory canal flap can be attached to the newly opened window of the outer semicircular canal. The spasm of the inner ear cavity, the tympanic membrane tendon, the facial nerve horizontal section, the vestibular window, the tibia, the iliac tendon and the drumstick can be clearly revealed and examined under the operating microscope. The ear sclerotic lesions were examined with a fine needle for the degree of fixation of the tibia. 5. Prepare the window skin to first check whether there is a crack in the outer ear canal skin, and whether it is intact with the eardrum; rinse the skin, wash away all bone powder and debris; remove the subcutaneous tissue. At the outer end of the boundary between bone and cartilage, a curved incision is made from 1 to 6 o'clock, parallel to the ear incision, and the posterior wall flap of the external auditory canal is divided into two parts, the outer part of the papillary cavity, and the inside is 6,1 At the point, make two incisions parallel to the long axis of the external auditory canal, and reach the outer edge of the drum ring by 1mm. This flap retains the outer ear canal vascular pattern for the cover window, and is protected from the external auditory canal by the saline pad. Electric drill damage. 6. Semi-regulator opening window (1) Top cover method: Firstly, the 2.5 mm fine-grain drill or diamond drill bit is used to extensively grind the bone layer of the labyrinth from the posterior part of the ampulla of the outer semi-circular canal, causing the bone to be pale yellow and looming. When the needle is large and fine, it indicates that the endogenous cartilage layer has been reached. After the layer is further worn away, the light blue color is the endosteal bone layer. Then use a diamond drill bit of 0.8~1mm to grind the bone around the window to be opened until an elliptical dome-shaped top is formed there. Finally, the endosteal bone is further removed along the periphery of the top cover, showing a deep blue line. The semicircular lumen is already open there. If the local anesthesia surgery patients feel hearing improvement, accompanied by nausea, vomiting, dizziness, at this time, the patient can gently breathe deeply, do not move. Use a thin needle to connect the blue line around the top cover, and use the splitter to extend the top cover from the front to the back to avoid damage to the facial nerve. The splitter should not protrude into the semicircular canal to prevent the membrane from getting lost. The window size is about 4mm×1.5mm. The window edge is not flattened with a splitter. The thin needle peels off the edge of the window or makes it turn outward. Wrap around the window edge, if there is blood or bone debris into the external lymphatics, rinse with warm saline. At this time, the membrane is lost in the noodle lymph in the noodle, and the faecal at the front end is the ampulla of the outer semicircular canal. Do not aim at the window, but rather attract it around the perimeter to prevent the membrane from getting lost. (2) Broken shell method: After the semi-regular tube is thinned, the bone wall is fragmented, and a window is formed after being taken out. 7. Cover the skin after opening the window, quickly remove the cotton piece and the small oil gauze over the outer ear canal skin piece, gently wipe the skin piece with the squid of salt water, wipe off all the bone chips, and exhaust the middle ear cavity. Inside the blood, quickly cover the skin on the window, cover the surface of the skin with a 1.0cm × 0.5cm Vaseline oil gauze in advance, and then use the iodoform gauze to compress the mastoid cavity and the external auditory canal. The piece, until the finger presses the outer ear canal gauze, the eyeball is displaced to the opposite side, indicating that the skin has been in close contact with the membrane. 8. Incision suture the front of the earring to suture 3 needles with a thin thread, cover dressing and bandage dressing. 9. The other two fenestration methods are as follows: (1) Improved inner ear fenestration: its characteristics divide the posterior wall skin of the external auditory canal into two parts, the upper part covers the sinus and part of the sinus sinus, and the lower part covers the facial nerve sac. The thiersch inner skin of the thigh is taken to cover the window and the mastoid cavity, and the leading edge of the skin is connected to the edge of the tympanic membrane and then fixed by a sliver. Some people think that the outer ear canal cover window with bone clothing is easy to produce window bone healing, and Thiersch skin film has no such drawback. According to reports, there is no significant difference in long-term efficacy between the two skin flaps. (2) Two-story inner ear fenestration: its characteristic is that it does not make a conventional external ear canal tympanic membrane, so that the separated external ear canal skin remains in its original shape, and the window and the mastoid cavity are covered with Thiersch skin and external ear canal. At this time, the outer ear canal and the mastoid cavity are separated by the inner end skin of the upper and the posterior wall of the external auditory canal. The space between the mastoid cavity and the middle ear cavity is separated by Thiersch skin, and the new window is located on the "upstairs" of the mastoid cavity. Living in the "downstairs", the pressure difference between the two windows of the tympanum is as good as possible, so that the basement membrane can be displaced as much as possible, and cotton can be plugged outside the "downstairs" tympanic membrane to make new windows and snail windows. The difference in acoustic pressure between the two increases, and the hearing increase is increased by 5 to 10 dB.

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