Surgical surgery for tumors in the third ventricle and pineal region through the lateral ventricular trigone approach

The resection of the pineal region tumor through the lateral ventricle triangle was first reported by Van Wagenen in 1931, and a good result was obtained in the removal of a pineal tumor. Suzuki (1965) and Poppen (1968) have adopted this approach. Some scholars in China reported in 1979 and 1983 that 18 cases of posterior third ventricle and pineal region tumors were also treated with this method. In order to reduce and prevent postoperative unilateral hemianopia, Van Wagenen's "L" shaped incision of the apical lobes was changed to a straight incision in the intervertebral sulcus. There were no visual field defects or only quadrant unilateral hemianopia. The advantage of this approach is that the enlarged lateral ventricle and the thinned triangular region reach the posterior part of the third ventricle and the pineal region, which is more likely to reveal the tumor, and can prevent the tumor from being in the brain due to direct contact and resection of the tumor. Intravenous and cerebral venous injury is a good surgical approach. Treating diseases: brain tumors Indication The third ventricle and pineal region tumor surgery through the lateral ventricle triangle is applicable to: 1. Large tumors in the posterior part of the third ventricle and the pineal region, and the lateral ventricle is obviously enlarged. 2. Patients with tumor recurrence after other surgical approaches. Contraindications 1. Tumor resection should not be preferred for germ cell tumors in the pineal region sensitive to radiotherapy and gamma knife treatment. 2. Tumors extending to the posterior cranial fossa. Preoperative preparation 1. The patient has an increased intracranial pressure before surgery. CT or MRI shows that the ventricle is enlarged, and ventricular drainage can be performed 1 to 2 days before the operation. 2. Usually, the ventricle drainage is performed on the forehead or occipital angle of the opposite side of the operation before the craniotomy, and it is removed within 5 to 7 days after the operation. Surgical procedure 1, scalp incision The right top flap incision, forward to the posterior center, up to the sagittal midline, posterior to the anterior occipital lobe, the flap turned to the outside. 2, bone flap craniotomy Do 4 to 5 skull holes, the medial bone hole is located next to the sagittal sinus, the outer hole is 6 to 7 cm from the midline, and the bone flap is turned to the outside. 3, dural incision The dural valvular incision is opposite to the cutaneous flap. The basal is connected to the sagittal sinus. After the incision, the suture is pulled toward the sinus side. 4, brain incision Van Wagenen used a humeral flap to make an L-shaped incision in the parietal lobe, which was almost cut off from the side-viewing radioactive fibers. Can be changed to the top parietal incision of the right parietal lobe, the front end of the incision is 1~2cm away from the center, and the incision is 4~5cm along the interdural furrow. 5, reveal the tumor As the lateral ventricle enlarges, the parietal lobe becomes thinner and thus more easily enters the lateral ventricle. Arrive at the posterior and triangular areas of the lateral ventricle, see the posterior horn of the choroid plexus and the lateral ventricle, and fill the posterior and posterior part of the lower corner with a saline pad to prevent the blood from flowing to other parts of the ventricular system. Postoperative meningeal irritation. In the triangular area, the choroid plexus bulbs are electrocoagulated and resected to reduce the secretion of cerebrospinal fluid, which is helpful for patients to experience postoperative cerebral edema and increased intracranial pressure. The side wall of the triangle of the choroid plexus is equivalent to the cingulate gyrus of the pineal body, and is probed to the pineal region and the posterior part of the third ventricle. The diameter of the tumor is 2 to 3 cm, and the thickness of the inner wall is generally not more than 2 cm. Large tumors with a diameter of 3 cm or more often see the inner wall being compressed by the tumor and bulging, and the tumor can be found only by sucking a few millimeters with a suction device. 6, tumor resection The operation is best performed under a surgical microscope. There are many types of tumors in this area, such as teratoma and meningioma, and some types of gliomas such as ependymoma and astrocytoma (I, II). Although there is no membrane for pineal cell tumors, there are certain boundaries with the surrounding structure. Stripped along the surface of the tumor, with a cotton strip with a tail line placed between the tumor and the surrounding structure, in addition to protecting the important structure from damage, can also be used as a stripping, hemostasis and preventing bleeding through the third ventricle to the midbrain aqueduct and Lateral ventricle spread. Bipolar electrocoagulation occludes the tumor capsule or tumor surface vessels, and continues to expand the scope of electrocoagulation, the tumor volume gradually shrinks, taking the tumor forceps and bipolar electrocoagulation for partial resection of the tumor center. The tumor with the capsule is resected intracapsularly, and the hard tissue can be excised by CUSA or laser gasification. As the tumor becomes smaller, the residual part is further freed and excised. A benign tumor with a clear membrane or a clearly defined adhesion to the surrounding structure can be completely cut or completely cut under the naked eye. If the tumor base is wide or difficult to separate from the surrounding structure, subtotal resection is feasible. Malignant glioma (Class III, IV) has no clear boundaries and can only be partially or partially removed. The tumor bed is fine to stop bleeding, remove the intraventricular cotton film, try to clear the blood clot in the brain, especially the obstructive blood clot at the upper mouth of the midbrain aqueduct. Repeat the flushing with a large amount of normal saline to prepare the ventricular continuous drainage, and set one end of the silicone tube to the same The anterior horn of the lateral ventricle, the other end was extracted through the parietal cerebral incision and another small scalp incision. The end of the tube is folded, wrapped with gauze and tightened with a rubber band, and the continuous drainage device is connected after the operation. 7, the skull The dura mater is tightly sutured, the bone flap is restored, and the periosteum, cap aponeurosis, and skin are sutured. complication 1. The same direction hemianopia, damage to the radiation fiber. 2. Hypothalamic injury, manifested as low body temperature, disturbance of consciousness and stress ulcers. 3. Hydrocephalus, postoperative cerebrospinal fluid circulation pathway is blocked, or caused by malabsorption. When continuous drainage through the ventricle cannot be improved, shunt should be performed.