Skull base tumor surgery

Treatment of diseases: intracranial tumor meningioma Indication 1. Intracranial tumors invade the skull base and maxillofacial neck, such as meningiomas, neurofibroma, chondromas and teratomas. 2. Tumors originating from the base of the skull, such as osteoma, giant cell tumors, etc. 3. Extracranial tumors invade the skull base. The malignant tumor of the maxillary sinus invades the infraorbital fossa and the skull base; the malignant tumor of the parotid gland invades the skull base; the jaw sarcoma, chondrosarcoma and maxillofacial soft tissue sarcoma involve the skull base and the outer ear, middle ear and facial skin squamous cell carcinoma invade the skull base, etc. . 4. Although the above-mentioned malignant tumor has cervical lymph node metastasis, it has not yet been invaded and fixed in the internal carotid artery. Contraindications 1. The tumor has been extensively invaded into the brain. 2. The tumor has approached or crossed the midline of the skull base. 3. The tumor has invaded the upper wall of the sphenoid sinus or the pharyngeal mucosa. 4. There are already distant transfer. Preoperative preparation 1. X-ray examination to understand the involvement of the skull and facial bones, according to the location and extent of the tumor, X-ray film and body slices of different projection positions can be selected. Carotid artery and cerebral angiography of the femoral artery are often needed to determine the relationship between the tumor and the internal carotid artery and internal jugular vein. If necessary, CT scan or magnetic resonance imaging examination can more clearly understand the extent of tumor invasion in the skull base and intracranial. 2. Cranial nerve examination should routinely check whether I~XII has dysfunction of cranial nerve, which has important reference significance for analyzing and understanding the location and nature of tumor involvement. 3. If there is a possibility of ligating the internal carotid artery during operation, the carotid artery compression test and training should be performed before surgery until it can withstand more than 30 minutes, and the brain is confirmed by EEG, cerebral blood flow diagram and carotid angiography. A good collateral circulation has been established for surgery. 4. If you need to remove the maxilla or mandible during operation, you should make a sacral or slanted guide and a device for ligation between the jaws before surgery. 5. Bacterial culture and drug susceptibility test for oropharynx and tumor before surgery. Penicillin, chloramphenicol or sodium sulfamethazine was given 1 day before surgery to prevent infection. 6. 1 to 2 days before surgery to clean the teeth. Rinse mouth with a mouthwash, use antibiotics to drop the ear, nose, and clean the ear canal and nasal passages. 7. Full scalp skin preparation, cleaning and disinfection. 8. According to the scope of surgery, adequate blood preparation. Surgical procedure 1. Surgical procedure for removing the tumor in the anterior region of the skull base (1) Incision: A coronal or semi-coronal incision that extends down to the front of the ear. If a neck sweep is to be performed at the same time, the incision is extended down to the neck and is S-shaped. To remove part of the rock bone, place the incision behind the ear, cut the external auditory canal horizontally, and turn the ear forward with the flap. (2) Flap: The scalp flap is turned up in a typical manner. In the face and neck, the flap is turned forward and the front side is dissected to the lateral edge of the ankle. (3) Craniotomy: remove the frontal sacral bone flap. The temporal lobe is pulled back until the tumor is revealed. Lightweight anatomy separates it. Use a rongeur to bite the side of the skull until the base of the skull for better exposure. (4) Expand the approach: do a total parotidectomy that preserves facial nerves. The mandible ascending branch is removed to obtain a good exposure. If you plan to replant the mandibular branch, you should maintain your chewing muscles to maintain its blood supply. Similarly, the front and rear ends of the zygomatic arch are cut off and removed. As such, the tumor may be seen from below. (5) Neck dissection: In some cases, radical neck dissection is performed because the tumor has spread to the neck or to facilitate identification of tissue entering the skull base. (6) Revealing the skull base tumor: Starting from the ear, the deep surface of the facial nerve is dissected along the base of the skull until the site where the tumor is located, and the internal jugular vein is cut to protect the carotid artery. In most cases, the tumor can be completely removed from the periphery of the skull. In benign tumors, such as neurofibroma, the skull base is removed with a rongeur until the tumor and its included bone holes are revealed. (7) When necessary, the outer side wall of the crucible should be inspected, or even the wall removed, and the contents of the crucible can be removed at the same time. Some of the more malignant tumors need to remove part or all of the tibial rock. Tumors with an envelope, such as neurofibroma, can be removed. Put the tibia back in place and fix it with wire. The ineffective cavity left by the tumor removal is prone to hematoma formation and infection, so it should be filled with a sternocleidomastoid muscle flap with good blood supply. The scalp is sewed back to the original position and drained with a negative pressure. If the truncated mandibular branch still retains the muscle pedicle, it should be replaced and fixed. If it is completely cut off, it should not be replaced, as it often forms a dead bone. 2. Surgical procedure for resection of the tumor in the middle of the skull base (1) Incision: Make a long incision on the scalp to facilitate turning up the iliac bone flap, the incision down to the ear area, where it is often necessary to sacrifice a portion of the skin or outer ear and continue to extend to the neck to form an S-shaped incision. . In most cases, cervical lymphadenectomy is performed first, which simplifies the procedure here, as it is easier to ascertain the tissue at the base of the skull. (2) flap, craniotomy: flip the scalp flap and remove the humeral bone flap. This reveals the middle cranial fossa. Lift the temporal lobe from the base of the skull. The dura mater is separated from the tympanic cap. If the dura mater is violated here, it shows a poor prognosis. (3) Enlargement of the approach: In order to reveal, remove the parotid gland, facial nerve and part of the lower jaw. Cut and ligation of the internal jugular vein. The anatomy in front of the rock bone is performed from below along the skull base. Use the rongeur to remove the bone from this area to the occipital foramen. Remove the skull base at the back of the rock bone, but be careful to avoid damage to the lateral sinus. The lateral sinus can be separated and ligated. The lateral sinus should be ligated before the internal jugular vein is ligated. If the internal jugular vein is ligated, the pressure on the lateral sinus will increase. (4) Exposing the internal carotid artery: When the internal carotid artery emerges from the rib fracture through the rupture hole in the skull and when it enters the bone tube from below at the base of the skull, the internal carotid artery is exposed. (5) Removal of the rock bone: The bone drill and the rongeur are used in combination, and the inner wall of the inner tube of the rock bone is cut out from above and below. The inner carotid artery is protected with a thin metal strip retractor and this step is done very carefully. The rock bone is lightly treated until it is loose and can be removed together with the cervical anatomical specimen to repair the dural defect, suture the scalp incision, and place drainage. 3. Surgical procedure for resection of the tumor in the posterior region of the skull (1) Incision: The anterior head flap is placed under the pedicle, and the forearm of the incision can be extended down to the neck to reveal a downwardly expanding tumor. Make a forward small transverse incision under the ear to facilitate separation and determination of the facial nerve. When the tissue flap is turned up, it will become thicker and thicker, especially when changing from longitudinal to transverse, along the skull to the occiput. When the large holes are separated. This is due to the fact that many muscles such as the occipital muscle, the sternocleidomastoid muscle, and the longus muscle are removed from the bone surface. (2) Craniotomy: After lifting the bone flap, use the rongeur to bite the bone below to push the cerebellum and expose the tumor. (3) Reveal the facial nerve: find and pull the facial nerve through the transverse incision under the ear. The picture shows the relationship between the location of the tumor and the base of the skull. (4) Revealing the tumor: removing or pulling the lower part of the parotid gland. The tumor is located behind the mandibular angle and is partially covered by the sternocleidomast muscle. The tumor extends up to the base of the skull and expands downwards and inwards. In most cases, the internal jugular vein can be ligated and the tumor isolated from the internal carotid artery and the pharyngeal wall. (5) Resection of the tumor: separation upward to the jugular foramen of the skull base. All the skull base bones were removed to the edge of the jugular foramen and the edges were removed, and the intracranial part of the tumor, the internal jugular vein and the extracranial part of the tumor were removed. If a brain has been violated, it should also be removed. (6) Closing the wound: Even if the bone flap is placed back, some defects will be left behind. Moreover, due to the removal of the tumor, there is also an extracranial soft tissue defect. In order to repair the bone defect and eliminate the invalid cavity, as well as reduce the chance of infection, the sternocleidomastoid muscle flap can be used to fill the ineffective cavity. Close the scalp incision and place a negative pressure drainage. complication Cerebrospinal fluid leakage The main reason is that the repair of intraoperative dural injury is not perfect. A small amount of cerebrospinal fluid leakage is expected to self-heal in about 7d. Or after a few days of continuous drainage through the lumbar puncture, the severe cerebrospinal fluid leakage needs to be repaired in the second stage. 2. Epidural hematoma The main reason is that the hemostasis is not perfect during operation. There is no drainage tube or blood transfusion after operation, and the blood coagulation ability is poor. No blood coagulation agent is used after operation. The patient's consciousness, pupil size, and response to light, blood pressure, pulse, respiration, and physical activity should be closely observed after surgery. If there is irritability, change of consciousness, dilated or reduced pupillary pupil, increased blood pressure, slow breathing and pulse, and weakened contralateral muscle strength or abnormal limb activity, timely surgical exploration, treatment of bleeding points, proper placement and drainage, Use coagulation drugs. 3. Infection Brain abscess, meningitis, cellulitis and pneumonia may occur after surgery. Use sensitive antibiotics and sulfonamides to prevent it. Turning over after surgery, encouraging patients to cough, early bed-out activities, etc. help prevent pneumonia. For respiratory secretions that are thick and sticky, patients who are weak and not easy to cough up themselves should be treated with preventive tracheostomy to enhance the suction of endotracheal secretions.

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