cerebellopontine angle meningioma resection

Cerebellar pons is one of the most common sites of intracranial meningioma, accounting for about 10% of intracranial meningioma. The base of the tumor is attached to the sigmoid sinus, the superior sinus, the inferior sinus or the internal jugular vein. Its location is close to the cerebellum, located in front of or outside the cerebral horn of the cerebellar bridge. Tumor enlargement often involves adjacent cranial nerves and oppresses the cerebellum and brainstem. Some meningioma grow up through the cerebellar lobes to the posterior fossa. Such meningioma has the common characteristics of meningioma, and blood supply is very rich. A portion of the blood supply artery enters the base of the tumor from the dura mater and a portion directly from the branch of the vertebral basilar artery. Because the tumor is very deep, the tumor is large and attached to the dura mater and sinus, surgical resection is sometimes difficult, and must be well exposed, careful operation and hemostasis. The clinical manifestations are typical of cerebellar pons syndrome, similar to acoustic neuroma, but the vestibular function and hearing impairment are usually lighter than the acoustic neuroma, and the inner ear hole is not enlarged. Treatment of diseases: spinocerebellar ataxia, cerebellar meningioma Indication Cerebellar pons retinal meningioma resection is applicable to: 1. Meningiomas located in the cerebellum and pons. 2. Cerebellar cerebral horn meningioma has been extended to the mid-cranial fossa or midline. Contraindications 1. The late giant meningioma, the patient has been depleted. 2. This part of meningioma has extensive bone destruction, and there are malignant signs, surgery should be carefully considered. Preoperative preparation 1. MRI brain scan to determine the location, size and extent of the tumor. 2. Vertebral angiography can be performed to understand the blood supply of the tumor. 3. The intracranial pressure was significantly increased, and the ventricular continuous drainage was performed before operation. 4. Fully prepare blood. Surgical procedure Incision Craniotomy of the posterior cranial fossa, incision of the occipital sinus posterior approach for acoustic neuroma resection, but the larger the tumor, the bone window should be expanded as much as possible, and the occipital foramen and the posterior arch of the atlas should be opened to facilitate the expansion of the surgery. Pressure. 2. Meningeal incision, exploration of tumor Dural flap or radial incision. According to the procedure of the acoustic neuroma resection, the cerebellar hemisphere is first retracted from the side to the midline to reveal the tumor. Meningioma is nodular, the size of the tumor is different, and the surface blood vessels are very rich. As much as possible, the blood supply artery entering the tumor is electrocoagulated and cut off one by one before the tumor is removed to reduce bleeding. 3. Tumor resection In the case of a small tumor volume, the tumor is gradually electrocoagulated and separated at the base of the meninges of the tumor, so that the tumor is detached from the dura mater. The tumor was sutured with a silk thread and gently pulled to the outside. Look at the blood supply artery located in the front and the inner side of the tumor, do not damage the sinus, protect the trigeminal nerve and facial nerve near the tumor, and free the tumor. Treatment of larger tumors: After electrocoagulation cuts off the blood supply artery, the tumor capsule is incision, and intratumoral segmentation is performed to reduce the tumor volume, and then the tumor is completely cut. If the tumor is huge, it has been closely adhered to the brain stem or important cranial nerves, preferring to leave that small piece of tumor tissue, and can not blindly force the tumor to be completely cut. The residual tumor tissue is treated by electrocoagulation. If the meningioma is huge, a surgical approach with a double incision in the posterior cranial fossa can be used. A midline incision was made in the posterior cranial fossa, and extensive decompression of the posterior cranial fossa was performed. Conducive to tumor exposure, resection and postoperative decompression. When the tumor develops to the middle cranial fossa at the same time, the tumor is removed by the superior and inferior cerebral approach. 4. Carefully stop bleeding, rinse the wound, suture the dura mater or enlarge the repair. The muscle, subcutaneous and skin layers are sutured layer by layer. complication 1. Local compression and dressing after meningitis is not enough, forming a pseudocyst, secondary infection. 2. Facial nerve injury In the application of microsurgical techniques, this complication has been significantly reduced. 3. Brain stem injury surgery directly damages or damages the supply artery. 4. The 9th and 10th cranial nerve injuries. 5. The 5th and 7th cranial nerve injuries cause corneal ulcers.