Infratemporal fossa approach

Fisch designed three approaches for humerus and lateral skull base tumors: Type 1A inferior fossa approach: the main exposed area is the labyrinth, the tip of the rock, the mandibular fossa, and the posterior inferior fossa. Type 2B infraorbital fossa approach: The main exposed areas are the tip of the rock bone, the slope area, the horizontal section of the internal carotid artery, and the eustachian tube area. 3C type inferior fossa approach: mainly reveals the infraorbital fossa, pterygopalatine, saddle, nasopharyngeal and other areas. Curing disease: Indication 1. Jugular spheroid tumor. 2. Invasion of the internal carotid artery and apex of cholesteatoma. 3. Underarm brain tumors. Contraindications 1. The tumor has clearly invaded the internal carotid artery. 2. The contralateral vagus nerve is damaged. 3. The tumor is invasive in the brain and can not be completely removed. Preoperative preparation Lateral skull base surgery is performed in the internal carotid artery region, which may damage the artery. Before the operation, it is necessary to understand the vascular and cranial medial branches in a more detailed manner. Therefore, it is necessary to examine the internal carotid artery angiography, decompression test, and ocular plethysmography. Other preoperative preparations are the same as the anterior skull base surgery. Surgical procedure 1. Type A underarm approach (1) Incision behind the ear: In order to expose the large blood vessels and nerves of the neck, the incision of the AB segment of the ear can be extended to the incision of the BC segment. For the preparation of the diaphragmatic flap, the incision of the AD segment can be extended. (2) Open the tissue flap and treat the cut surface of the external auditory canal: separate the tissue flap in front of the incision, and pull forward, and the periosteum in the mastoid area is separated to form a tissue flap pedicled in front. The external auditory canal was cut transversely, and the external auditory canal was sutured and closed as a blind tube on the cut surface. The periosteum flap was reversed forward and sutured to the periosteum of the external auditory canal to be closed as the second layer. (3) The main nerve vessels are exposed in the upper neck: the BC segment of the skin incision is extended downward, and the anterior border and the medial side of the sternocleidomastoid muscle are separated and pulled backward. The second abdominal muscle is found in the deep part of the muscle front, and it is separated upwards, and the facial nerve can be found in front of the upper end. The upper part of the parotid gland is excised to further reveal the main trunk and main branches of the facial nerve. The submandibular tissue is pulled forward, and the sternocleidomastoid muscle is pulled backward to expose the internal jugular vein and the common carotid artery. The vagus nerve can be found between the two blood vessels. A deep sub-abdominal muscle can be seen across the sublingual artery. An accessory nerve is visible on the surface of the internal jugular vein. If it is difficult to reveal these structures, the muscle can be cut at the upper end of the second abdominal muscle and turned down, which increases the upper field of view. The internal carotid artery was isolated to the arterial hole. The internal jugular vein is hanging, but it is not ligated. (4) Open the mastoid cavity and tympanic cavity, reveal the facial nerve canal and sigmoid sinus: the external incision of the mastoid, separate the sternocleidomastoid muscle and periosteum, and separate the lower part of the diaphragm to pull up. Place the retractor so that the exposed area is guided from the external auditory canal to the mastoid. Use the electric drill to completely open the mastoid cavity, remove the sigmoid sinus bone plate, and expose the sigmoid sinus, second abdominal muscle spasm, facial nerve canal, and sinus sinus. In cases of jugular spheroid tumors, the dura mater was cut on both sides of the sigmoid sinus, and the sigmoid sinus was ligated with a blunt artery. The residual skin of the external auditory canal was separated to the drum ring, the drum ring was separated from the drum groove, the tympanic nerve was cut, the anvil joint was separated, the tympanic membrane was cut, the tympanic membrane and the hammer and the anvil were removed, and the tympanic cavity was exposed. The mastoid cavity is further enlarged, the bone wall of the external auditory canal is worn down, and the humeral arch is removed. The front lower part of the tympanic wall is ground to reveal the internal carotid artery. (5) Open the facial nerve tube and expose the facial nerve from the knee ganglion to the stem hole. Using a micro-shaped stripper, the facial nerve is freed from the facial nerve canal and displaced forward. (6) Open the internal carotid artery tube and enter the infraorbital fossa: use the electric drill to grind the tympanic cavity from the eustachian tube to the isthmus of the eustachian tube, and remove the bone of the inner wall of the eustachian tube to expose the internal carotid artery. Electrocoagulation of the isthmus of the eustachian tube, closing the lumen with bone wax. More bones are removed, the styloid process and muscles are cut, and the periosteum attached to the tympanic bone is cut open, that is, into the infraorbital fossa. The bone under the internal carotid artery is further removed, and the internal carotid artery is exposed to the inner side. The retractor is placed in the infraorbital fossa, and the mastoid cavity, the tympanic cavity, the upper neck and the infraorbital fossa are exposed. 2. Type B and C type inferior fossa approach B-type and C-type inferior fossa approach, most of the steps are basically the same as type A surgery. The differences are: 1 The slit extends further forward. 2 cut the zygomatic arch and connect it under the chewing muscle. 3 Cut off the pterygoid muscle and the upper part of the pterygoid muscle. 4 cut off the condyle, grinding more bone in the middle skull base, separating the anterior and inferior tibia, etc., so that the internal carotid artery rupture hole and other exposure is more fully. Because the mandible is pulled forward and down, the facial nerve tension is large, and it is often necessary to cut off the lower branch or the whole branch to cut the facial nerve (reconstruction at the end of the operation). Finally, the field can be exposed to the slope, saddle, nasopharynx, wing splitting and other areas. complication 1. Infection: Type A surgery communicates that the contaminated cavity is relatively light, but if the field is contaminated, it will be infected. 2. Cerebrospinal fluid leakage: more cases occur in the subarachnoid space. Intraoperative attention should be paid to repair the closed dura mater and filling pressure. 3. Cranial nerve palsy: The ninth and tenth pairs of cranial nerves may have dysphagia and cough after being damaged. It is feasible to feed the nose and wait for it to be compensated slowly. 4. Facial paralysis: facial nerves often appear to varying degrees of incomplete paralysis, but rarely numbness, generally recover 80%. 5. Others: such as tissue ischemic necrosis, cardiovascular accident, pulmonary embolism, cerebral edema, etc. can occur, can be treated accordingly.

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