middle cranial fossa approach eustachian tube plasty

The Eustachian tube is also known as the Auditory eustachian tube. The anterior wall of the eustachian tube is equivalent to the anterior superior quadrant of the tympanic membrane and extends inward, downward and forward to the side wall of the nasopharynx. It has a total length of about 35 to 39 mm and is composed of a bone and a cartilage. The bone is near the tympanic segment, accounting for 1/3 of the total length of the tube. The cartilage is near the nasopharyngeal end, accounting for 2/3 of the total length of the tube. It consists of 3 to 4 groove-like fibrocartilage, and the anterior lateral cartilage plate is more It is short, the posterior medial side is long, and there are no cartilage on the lower part and the outer side. It is surrounded by a fibrous connective tissue membrane and forms a fissure-like tube type, which is often closed. The tympanic opening of the Eustachian tube is called the mouth of the tympanic drum or the tympanic cavity. The opening of the nasopharyngeal end is called the pharyngeal opening and is located on the outer side wall of the nasopharyn From the tympanic cavity, the pharyngeal opening is forward, inward, and downward, and the tube is at an angle of about 40° to the horizontal plane, and is at an angle of about 45° to the sagittal plane. The tympanic cavity is approximately 2.0 to 2.5 cm above the pharyngeal opening. The widest part of the bone is the tympanic cavity. It has a funnel shape, an inner diameter of about 4.5 mm, the narrower inward, and the narrowest part of the intersection of the bone and the cartilage, called the narrow part, and the inner diameter is about 1.0 to 2.0 mm. From the isthmus, it gradually widens inward, reaching the widest point of the pharynx (triangular or elliptical), about 9.0mm long. In the cartilage of the eustachian tube, the levator muscle and the eustachian tube pharyngeal muscle are attached to the posterior lip, and the sacral muscle is attached to the anterior lip of the pharynx, so when yawning or doing swallowing, the three muscles The contraction opens the mouth of the pharynx, thereby adjusting the pressure of the tympanic chamber and maintaining the balance between the pressure on both sides of the tympanic membrane. The eustachian tube of the child is shorter than the adult, the lumen is relatively large, the isthmus is wider, not curved and like a straight line, at an angle of 10° to the horizontal, close to the level, so the inflammation of the nose and throat is easily invaded by this tube. Tympanum. The superficial sulcus of the granule is located on the inner side of the tympanic membrane half-tube and the eustachian tube, and is parallel to each other. It is the marker of the position of the tympanic membrane half-tube and the eustachian tube. The eustachian tube is located in front of the internal carotid artery. The eustachian tube stenosis is adjacent to the spine hole, the foramen ovale, and the external port of the internal carotid artery. The spine hole is below the outside of the gorge, the foramen ovale is in front of the lower part of the gorge, and the internal carotid artery is outside the gorge. The scorpion scorpion muscle and the squat levator muscle are the markers for finding the isthmus of the eustachian tube. The sphenoid bone spine is the protrusion of the outer side of the spur hole, which is easy to touch, and is adjacent to the isthmus of the eustachian tube. It can also be used to find the isthmus of the eustachian tube. Important sign. The sphenoid spine is located behind the narrow mouth of the eustachian tube. Due to the complex relationship between the anatomical parts of the eustachian tube, especially when the eustachian tube is completely blocked, it is extremely difficult to perform eustachian tubeplasty. It is an important condition to perform tympanoplasty, hearing reconstruction, and normal function of the eustachian tube. Therefore, the following eustachian tubeplasties are optional. Treatment of diseases: chronic otitis media, adhesive otitis media Indication 1. Chronic non-suppurative or adhesive otitis media, preoperative X-ray angiography or sacral CT showed that the isthmus of the eustachian tube was completely obstructed and required tympanoplasty. 2. Tumors that originate in or around the eustachian tube, such as meningioma, hemangioma, and the like. 3. Preoperative preoperative acoustic impedance test, Valsalva drinking water or catheter ventilation can determine the eustachian tube dysfunction. Contraindications 1. The tympanic lesion has an acute infection; the systemic chronic disease, the resistance is weakened. 2. Hearing examination is a sensorineural hearing loss. 3. The acute inflammation of the nose, sinuses and nasopharynx is unhealed. If there is inflammation in the skin of the operation area, surgery should be suspended. Preoperative preparation 1. Cranial fossa surgical instruments, tympanoplasty instruments, eustachian tube whale bone probes. 2. Completely shave your hair before surgery. 3. Preoperative benzobarbital 0.09g, enema. 4. Atropine sulfate 0.5mg into the operating room before subcutaneous injection (adult amount). 5. Fast food and water in the morning. Surgical procedure 1. The incision was anesthetized with 1% lidocaine containing 1:1000 adrenaline infiltration. For injections and incisions, please refer to "Cranial fossa into the nerve decompression of the road". 2. Separate the dura mater. Separate the dura mater from the bottom of the cranial fossa with a stripper and keep it intact. If there is tear, it can cause long-term cerebrospinal fluid leakage. After the dura mater is separated, the hook is used to lift the cranial fossa to expose the bottom of the cranial fossa. The following signs are recognized: 1 The facial nerve cleft through the superficial nerve of the rock. In most cases, the knee ganglion is covered with bone, about 5% to 15% of the knee nerve. Sections are exposed without bone coverage. 2 The spine hole through which the middle cerebral artery passes is a sign of the mouth of the eustachian tube. 3 The arched ridge is located behind the spine hole and is the upper semicircular tube mark. 3. Before the exposure, the top of the tympanic cavity and the eustachian tube are drilled with the diamond drill along the rocky superficial nerve to expose the bone, expose the knee ganglia and facial nerve, tympanic crypt and middle ear, remove the bone of the tympanic anterior tympanic cavity, and then enter the eustachian drum. Tube to the isthmus, and then remove the fibrous tissue or hyperplastic bone in the tube. 4. Insert a 2mm diameter silicone or plastic tube into the cartilage of the eustachian tube and expose it to the nasopharynx opening. The outer end is placed at the mouth of the eustachian tube, so that the normal mucosa of the eustachian can grow along the silicone or plastic tube. The ends of the lumen are thick silk lines, which are respectively taken out by the perforation of the tympanic membrane, fixed in the external auditory canal, and are taken out from the pharyngeal opening and fixed in the nasal anterior hole through the nasal cavity. 5. Place a bone piece or a small silica gel plate and a diaphragm of the diaphragm to cover the top of the tympanic cavity to prevent dural drooping and adhesion to the bone. 6. Remove the hook to reset the cerebral temporal lobe of the bulging part, reset and drill the remaining humeral bone piece, suture it with silver wire, suture the wound with the gut and silk thread, and cover with sterile gauze. After eustachian tube formation, the hearing has different degrees of improvement, but if the tympanic sound structure is more serious, it is necessary to use different surgical methods for hearing reconstruction after several months. complication 1. Damage to the dura mater caused by cerebrospinal fluid leakage or cerebral palsy. 2. Bleeding. 3. Damage to the ossicular chain and hearing loss. 4. Damage to the facial nerve.

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