Stereotactic Brain Lesion Biopsy

Any lesion in the brain, whether neoplastic or non-neoplastic, requires pathological judgment. A clear pathological diagnosis is the basis for a neurosurgeon to decide how to treat, whether to have surgery, and a prerequisite for determining radiation and chemotherapy. With the help of the brain stereotactic device, it is possible to accurately obtain the lesions in the brain, especially the small lesions in the brain, in order to clarify the pathological properties and perform correct treatment. At present, stereotactic biopsy has been widely used. Ordinary X-ray stereotactic biopsy, neurological complications (increased intracranial pressure caused by ventriculography, iodine allergy, puncture injury, brain edema, intracerebral hematoma) 5% to 10%, while CT, MRI Guided stereotactic biopsy complications are only 1% to 4%. Kelly et al (1991) reported 543 cases of deep brain biopsy: the diagnosis rate was 98%, the mortality rate was 0.2%, and the complication was 0.4%. Barnett et al (1997) reported 218 cases with a 3.7% complication and no operative death. The Navy General Hospital (2001) underwent CT and MRI-guided stereotactic deep brain biopsy in 605 cases, with a diagnosis rate of 97.5%, complications of 2%, and mortality of 0.5%. With the development of biopsy instruments and diagnostic techniques, the accuracy of stereotactic brain biopsy has been increasing. Therefore, for the diagnosis of intracranial deep invasive tumors with unclear diagnosis, stereotactic biopsy should be considered before craniotomy. The directional instruments used in intracranial lesion biopsy are mainly divided into two categories: one is small, the design is simple, and it is fixed on the skull hole, mainly based on the X-ray film skull marker point positioning; the other type is large, the design is complicated, there is one The circular or rectangular frame is placed on the patient's head, and the skull is drilled into the skull barrier to fix it. The reference points on the frame are positioned for X-ray, CT and MRI. Here we mainly introduce stereotactic surgery for common X-ray positioning. Treating diseases: brain tumors Indication Stereotactic intracranial lesion biopsy is applicable to: 1. Undiagnosed deep brain lesions. In the past, craniotomy was used for exploration and the trauma was large. If the stereotactic biopsy is confirmed to be a malignant brain tumor, chemotherapy or radiotherapy may be feasible; if it is confirmed to be a radiation-sensitive tumor such as germ cell tumor, radiotherapy or gamma knife treatment may be used alone. 2. Multiple or diffuse occupying lesions in the brain and occupying lesions involving the bilateral cerebral hemispheres. Most of these lesions are difficult to surgically remove, and stereotactic biopsy can provide evidence for chemotherapy and radiotherapy (including intratumoral radiotherapy). 3. Skull base tumors with high risk of surgery and unclear nature. 4. It is suspected that the brain lesions caused by viral encephalitis or systemic diseases (such as leukemia, Hodgkin's disease) also need to determine the pathological properties before treatment. Contraindications 1. Age less than 2 years old, thin skull (<3mm), can not fix stereotactic instrument. 2. Those who have coagulation disorders. 3. The lesion in the brain is vascular or blood-rich. 4. Located in the ventricle lesions. 5. Diffuse lesions in the lower brainstem. 6. Suspected of cerebral cysticercosis or brain worms. Preoperative preparation 1. Blood routine, platelet and clotting time check. 2. In the morning, fast water, shaved hair in the operation area or disinfected with a sterile solution. 3. Phenobarbital sodium 0.1g (2 ~ 4mg / kg in children), intramuscular injection 30min before surgery. Surgical procedure 1. After local anesthesia, a small hole cranial drill (diameter 3 cm) is used to drill the skull. The lesions are in the frontal and saddle areas. Generally, the holes are drilled 3 cm away from the front of the coronal suture and the sagittal suture. Pineal body area, parietal lobe, temporal lobe, and occipital lobe lesions were mostly drilled at the parietal nodule. If the forebrain lesion is selected for the forehead approach, drill 1 to 2 cm after the coronal suture and 3 cm beside the midline to ensure that the puncture path is parallel to the longitudinal axis of the brainstem; if the cranial fossa is selected through the cerebellar approach, the extra-occipital approach is thick. 3~5cm under the ridge and 3cm next to the midline. 2. Fix the positioning device of the stereotactic instrument to the patient's head. 3. Using the stereotactic calibration system, the determined biopsy target points are converted into X, Y, Z three-dimensional coordinate data. 4. Puncture the dura mater with a sharp instrument, and drill the stereotactic biopsy needle or stereotactic biopsy forceps to the target under X-ray or TV monitoring. 5. Select biopsy targets in combination with imaging diagnosis. Since the tumor center may be necrotic tissue, the appropriate part of the lesion should be selected during biopsy, and 2 or 3 lesions should be taken to improve the diagnostic accuracy. For specific operation, the biopsy needle can be drilled through the guide to the tissue within 5 mm of the lesion to take tissue, and then a piece of tissue is taken every 3 to 5 mm. When puncture and taking diseased tissue, the needle should be slow and gentle; if the resistance is obvious when withdrawing the biopsy needle, the biopsy tissue should be slowly released, and the force should not be pulled to avoid injury to important structures. 6. Pull out the biopsy device and stop bleeding. A small piece of gelatin sponge is attached to the dural incision, or the biopsy is placed in the biopsy area to stop bleeding. 7. Remove the stereotactic instrument and suture the scalp incision. complication 1. Intraoperative puncture site bleeding. When the biopsy mouth exits arterial blood or venous blood, it should be injected directly into the biopsy device with thrombin 1000-2000 U (dissolved in 2-5 ml water for injection). 2. Intracranial hemorrhage occurred after surgery. If there is subarachnoid hemorrhage, intraventricular hemorrhage, etc., coping with CT treatment; if the hematoma is large and causes brain compression symptoms, stereotactic or craniotomy should be performed to remove the hematoma. 3. Postoperative brain edema. Symptomatic treatment with mannitol and hormones. 4. Intracranial infections occasionally occur, using antibiotic control.

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