Resection of tentorial meningioma

Cerebellar meningioma is a rare tumor. In 1933, Andaal made the first report. According to foreign literature reports, about 2.5% to 3.9% of intracranial meningioma, more than 50 cases in the country reported higher than foreign countries, accounting for 3.2% to 6.1% of intracranial meningioma. The primary location of the tumor and the basal part of the cerebellar meningioma can be divided into: on-screen, under-the-scenes, trans-screen up and down and perforation. 1 On-screen type: The base is attached to the brain, which is wider. About 18% to 52% of the cases invade the sinus, transverse sinus and sinus. The main part of the tumor is on the cerebellum. Most tumors are also larger than the underlying type. It can be extended back to the back of the brain. 2 under the scene: most of the tumor is located under the cerebellum. Tumors originating from the underside, the base is mostly located next to the straight sinus. 3 cross-screen upper and lower type: the base of the tumor is mainly on the screen, and the tumor is mostly on the screen, and extends to the underside of the curtain. If the base is located under the curtain and penetrates the brain to the curtain, the growth speed is rapid. The early stage of this type of tumor can be larger than the curtain, and the volume on the curtain is much larger than the curtain. 4: The main basal part originates from the cleft hole of the cerebellum, most of which are suprated, and there are also subsurgical and tumors across the cerebral ventricle. For early detection and diagnosis, CT and MRI are the most ideal examination methods to understand the location, growth direction and size of the tumor, as well as between the tumor and the cerebellar hiatus, the cranial fossa, the cavernous sinus and the brainstem. Relationship. Carotid and vertebral angiography is helpful in understanding the blood supply to the tumor. These are all important in selecting surgical approaches and methods. Treatment of diseases: spinocerebellar ataxia, cerebellar atrophy Indication Once diagnosed as a cerebellar meningioma, surgery should be performed in principle. If the intracranial pressure is significantly increased, surgery should be performed as soon as possible. Contraindications There is no absolute contraindication. If it is closely adhered to an important structure, it is not advisable to force a full cut. If the general condition is poor or the vital organs have serious organic diseases, it is necessary to undergo appropriate treatment before surgery. Preoperative preparation 1. Take a skull slice to understand whether there is local hyperplasia or destruction of the skull; whether there is thickening and distortion of the vascular pressure trace leading to the bone hyperplasia or destruction zone, and whether there is a skull change with increased intracranial pressure. 2. Carotid angiography or digital subtraction examination mainly understands tumor blood supply, blood vessel distribution and tumor staining. 3. In order to reduce intraoperative bleeding, more preoperative embolization 3 to 5 days before surgery. 4. Fully prepared blood, often need more than 2000ml. Surgical procedure According to the different parts and types of tumor growth, the surgical approach can be divided into the top pillow or the top occipital approach, the suboccipital approach under the curtain, and the combined approach of the top and bottom pillows under the curtain. The surgical procedure for each type of tumor resection is as follows. 1. On-screen tumor resection (1) Incision: The tumor on the medial side of the screen can be used as the incision of the occipital occipital flap. (2) Bone flap formation: 4 to 5 skulls were drilled in the occipital sinus on the transverse sinus, and the occipital medial tumor was used as the occipital bone flap. The upper and lower cerebral tumors could be used to make the occipital occipital bone flap slightly forward. The bone flap opens to the side of the transverse sinus. The outer part of the near-rock bone can also be bitten and enlarged to the ankle if necessary. (3) Dural incision reveals the tumor: the sacral incision is made to open the dura mater and open to the transverse sinus side. The occipital cortex is cut into the transverse sinus and is cut off after electrocoagulation, but the Labbé vein in the posterior temporal lobe should be free. Try to keep it. The occipital lobe is retracted with a snake-type fixed retractor to reveal the tumor on the screen. (4) Tumor resection: the supratentorial tumor is adjacent to the rock bone and the superior sinus, and the deep part has important structures such as the midbrain and the anterior and posterior part of the pons, the trochlear and the oculomotor nerve, and the posterior cerebral artery. If the tumor is small, the base adhesion is not heavy, and it can be completely removed. However, the tumor is generally large, the base is wide, and the adhesion is heavy. It is best to perform intracapsular resection to reduce the tumor volume, and then make a circular incision around the base of the tumor. The tumor is removed together with the affected brain tissue. Sometimes a part of the tumor nodules that grow into the curtain should also be removed together. The on-screen tumor is adjacent to the sinus, sinus and posterior sagittal sinus. Note that the venous sinus should not be damaged when the tumor is free, especially when the tumor base and the sinus wall adhere to each other, it is best to perform intracapsular or segmental resection. The tumor tissue remaining in the sinus wall was separated and excised under a surgical microscope. (5) Guan skull: tightly sutured the dura mater, bone flap reduction, drainage of the hollow rubber under the epidural and aponeurotic aponeurosis, suturing the cap aponeurosis and skin. 2. Transsphenoidal tumor resection In general, the upper and lower joints of the occipital and suboccipital craniotomy are used to remove the larger on-screen and under-the-shoulder tumors. (1) Incision: Use one side of the top occipital barb incision or one side of the top pillow "S" shaped incision. (2) Craniotomy: a bone flap is made on the screen. After drilling under the curtain, the bone occlusion is enlarged to form a bone window. There is also a bone flap. The transverse sinus surface retains a strip-shaped bone bridge. (3) Exposure and resection of the tumor: the dura mater is made on the sac and the sinus, and the sinus side is turned over. The retractor is used to retract the occipital lobe and the cerebellum respectively, and the tumor tumor above and below the curtain can be revealed. Often the first to do the free and resection of the tumor on the screen, many authors' experience is: the removal of the tumor nodules under the curtain from the curtain is much easier than the removal of the onscreen tumor nodules from the underside. The tumor on the screen is resected, and the area of the brain that is involved in the tumor should also be removed. The tumor tissue involving the sinus wall needs to be carefully removed and the sinus wall should not be damaged. Then the tumor under the curtain is treated, the cerebellum is retracted downward, the blood vessels on the capsule of the tumor are electrocoagulated, the tumor tissue is removed by block, and finally the tumor is completely cut. It is difficult to completely cut the tumor against the straight sinus or sinus. Thin layer tumor tissue can be left without risking life. (4) Treatment of the affected transverse sinus: The tumor invades the transverse sinus. In order to completely cut the tumor, sometimes when a transverse sinus is needed, a thick silk thread can be temporarily ligated in the lateral part of the transverse sinus so as not to damage the sinus. The membrane is degree. After 30 minutes of blockade, if no brain swelling was observed, or the cerebral vein was dilated and congested, the proximal segment of the transverse sinus was ligated, and the tumor and a section of the affected transverse sinus were removed. For example, after a period of observation, brain swelling occurs. Some people advocate the anastomosis between the superior sinus and the sigmoid sinus. Some people take the patient's autologous saphenous vein and place it in the transverse sinus defect. (5) Guan skull: tightly suture the dura mater, bone flap reduction, dura mater external rubber hollow drainage, suture cap-like diaphragm and skin. 3. Subsurgical tumor resection Applicable to meningioma growth under the brain, surgical approach to the same lateral cranial fossa craniotomy, after the dural flap is opened, the cerebellar hemisphere is pulled down to expose the tumor. According to the size of the tumor and the extent of adhesion to the brain, complete resection and segmental resection, the affected brain curtain should also be removed. 4. Rupture tumor resection The location of the tumor is deep, and its deep proximity to the midbrain and its surrounding important blood vessels and cranial nerves is quite difficult and dangerous. Generally, the supratentorial craniotomy of the occipital humerus flap is used, and the occipital lobe is lifted and operated under a surgical microscope. Pay attention to the protection of important structures such as large cerebral veins, trochlear nerves, midbrain, posterior cerebral artery, trigeminal nerve, and oculomotor nerve in the deep part of the tumor. When the tumor and the important structure are heavily attached, the tumor should not be completely cut.