Cerebellar hemisphere tumor resection

Cerebellar hemisphere tumors are most common in gliomas (mainly astrocytoma), and a few are hemangioblastomas. Most of the children in the aneurysm are medulloblastoma, astrocytoma, ependymoma and hemangioblastoma. Astrocytoma, hemangioblastoma may have cystic. A tumor nodule is attached to the sac. The cystic change of the tumor, that is, the cystic fluid contained in the tumor is called the intratumoral capsule. The cerebellar tumor is adjacent to the fourth ventricle and often grows into the fourth ventricle. Ependymoma originates from the ependymal membrane at the bottom or side wall of the fourth ventricle, grows in the fourth ventricle, and protrudes into the cerebellar parenchyma. The hemangioblastoma is mostly located in the cerebellar hemisphere, and can also be located in the ankle and fourth. Brain room. In addition, there are metastases. In general, cerebellar hemisphere astrocytoma is the most common grade I hair cell astrocytoma, accounting for about 70%, and the rest are low-grade (II) and high-grade (III, IV) stars. Cell tumor. The hair cell type is benign and can be cured after full cut. Pencalet et al (1999) reported 168 cases of benign cerebellar astrocytoma with a total surgical rate of 88.7% and a 20-year survival rate of 90%, mostly restored to work and study. When surgically removing a tumor, care must be taken to prevent damage to the medulla, especially at the bottom of the fourth ventricle. Do not damage the posterior inferior cerebellar artery to avoid the risk of complicated brain stem ischemia or bleeding Treatment of diseases: cerebellar pons, meningioma, cerebellar tonsils, mandibular deformity Indication Cerebellar hemisphere tumor resection is applicable to: 1. Various types of cerebellar hemisphere tumors. 2. The tumor has extended to the fourth ventricle, or partially invaded the brainstem. 3. Metastasis, the patient's overall condition is still good. Contraindications There are no special contraindications, except for the patient's exhaustion. Preoperative preparation 1. There must be a correct positioning diagnosis before surgery. In recent years, due to advances in imaging inspection technology, clinical applications such as CT, MRI, and DSA have become increasingly widespread. The relationship between the location of the lesion and the surrounding structure should be analyzed before surgery in order to select the appropriate surgical approach, to obtain the best exposure, avoid the important structure of the skull as much as possible, increase the safety of the operation and strive for good Effect. 2. Skin preparation, wash the head with soap and water 1 day before the operation, shave the hair on the morning of the operation. You can also shave your head on the eve of surgery. 3. Fasting the morning of surgery. 4. Give phenobarbital 0.1g orally before surgery to ensure a quiet rest. One hour before the operation, 0.1 g of phenobarbital, 0.4 mg of atropine or 0.3 mg of scopolamine were intramuscularly injected. Surgical procedure 1. The incision is mostly made by a straight incision in the posterior cranial fossa, and the upper end reaches 4cm above the occipital trochanter, down to the plane of the 5th cervical spine. 2. The craniotomy step is the same as the posterior fossa decompression. The incision was retracted with a posterior fossa retractor, and the occipital scalpel was bitten and expanded as far as possible to the outside of the lesion side to increase the extent of cerebellar hemisphere exposure. The posterior arch of the atlas was 1 cm each about the midline. 3. "Y"-shaped incision of the dura mater, the tumor side can also be attached with an incision, open and suture the dura mater to facilitate exposure. 4. Exploring the tumor attention to the pulsation and tension of the cerebellar hemisphere, observing whether the surface color and the hemispheres on both sides are symmetrical, the tumor side is usually bulged, and sometimes the blood vessels on the surface of the brain are dilated, and the palpation is checked for the difference in softness between the hemispheres on both sides. Softer. In the local bulging of the cerebellar hemisphere tumor, the surface blood vessels are electrocoagulated, and the needle is slowly moved into the deep part by the brain needle to test the puncture. When the tumor is reached, there is a feeling of obstruction, and a small amount of tissue can be pumped for biopsy. Astrocytoma tissue is mostly taupe, gelatinous. In the case of a cystic tumor, there is a feeling of falling into the capsule and a yellow transparent cyst fluid flows out. 5. Resection of the tumor The tumor is located in the cerebellar hemisphere and can be infiltrated into the surrounding area. The small blood vessels on the surface of the cerebellar bulge were electrocoagulated, and the cerebellar cortex was cut transversely. The incision was 3 to 4 cm long, and the incision was retracted into the tumor with a brain plate. According to the appearance of tumor tissue and biopsy results, the nature and malignancy of the tumor can be initially determined. Substantial astrocytoma can be separated from the outside of the tumor by a brain plate, and the tumor is cut into a wedge shape or cut with a biopsy forceps. Tumor tissue can also be aspirated by an aspirator. Electrocoagulation stops bleeding. If the tumor has developed to the brainstem and the bottom of the fourth ventricle, surgical resection should be adequate. In the cerebellar hemisphere intratumoral tumor, the cyst is generally large, and the nodule in the capsule is not large. Such surgery can completely remove the nodules of the tumor, and the effect is very good. First make a transverse incision on the surface of the cerebellar hemisphere, separate the brain tissue, cut the cyst deep into the cyst, and remove the cystic fluid. The cyst fluid is light yellow and transparent. It can also be puncture in advance, aspirate part of the cystic fluid and then enter the capsule to see the nodule and its base, and completely remove it. Preoperative enhanced CT If the wall of the capsule can be strengthened, the wall of the capsule should be removed together. If the resection is difficult, it can be burned with a CO2 laser or a bipolar coagulator. The incision of the cerebellar hemangioblastoma surgery also uses the suboccipital midline incision. The tumor is nodular, purplish red, rich in blood supply, and has one or more large blood supply arteries. After electrocoagulation first enters the artery of the tumor, the tumor volume can be reduced. Free and pull the tumor, so that it is out of contact with the surrounding tissue, and can be completely removed. It is forbidden to remove the tumor before the electrocoagulation of the blood supply artery. Because of the bleeding, the operation is difficult. 6. The dura mater may not be sutured, but the muscle layer, subcutaneous and skin layers must be sutured layer by layer. The drainage tube can be placed in the tumor bed. If the tumor is completely resected, it is best to repair the dura mater, tightly suture the muscle layer, and pressure bandage to prevent local fluid accumulation after surgery. complication 1. The tumor may worsen the symptoms of cerebellar damage after resection. 2. Hemostasis, and hematoma in the posterior fossa. 3. Postoperative cerebral edema and increased intracranial pressure. 4. The muscle layer and the scalp are not tightly sutured, and when there is an increase in intracranial pressure, the cerebrospinal fluid may leak or form a pseudocyst.