Internal carotid artery bifurcation aneurysm clipping

The internal carotid artery bifurcation aneurysm accounts for 2.9% to 6.2% of all intracranial aneurysms, and the tumor top can point to the following three directions: 1 upward, extending into the frontal surface of the frontal lobe or the base of the olfactory bundle; Backward, extend into the anterior or posterior segment of the endplate, or the lateral fissure; 3 down, into the carotid or interstitial pool. The internal carotid bifurcation aneurysm is characterized by adjacent major arterial arteries: 1Heubner return artery; 2 medial bean vein artery from A1 segment; 3 lateral bean vein artery from M1; The perforating artery from the bifurcation of the internal carotid artery; 5 the anterior thalamic artery from the internal carotid artery and the posterior communicating artery; 6 the choroidal artery and its branches. The perforating artery from the bifurcation of the internal carotid artery often abuts the wall of the aneurysm. Treatment of diseases: intracranial aneurysms Indication Internal carotid bifurcation aneurysm clipping is applicable to: 1. The ruptured or unruptured internal carotid artery bifurcation aneurysm, the condition and physical condition can tolerate craniotomy. 2. A life-threatening intracranial hematoma after an aneurysm rupture. Contraindications 1. The condition of the aneurysm is critical after rupture, and it is in a state of sudden death (Grade V). 2. Patients with severe cerebral vasospasm and cerebral edema after rupture of aneurysm may be postponed. 3. The patient has severe systemic diseases such as heart disease, diabetes, kidney disease, lung disease, etc., and can not tolerate craniotomy. Preoperative preparation 1. Brain CT scan to observe the distribution of subarachnoid hemorrhage, with or without intracranial hematoma, hydrocephalus and brain swelling. 2. Cerebral angiography, it is best to perform digital subtraction of whole brain angiography to understand the size, shape and location of aneurysms, and the extent and extent of cerebral vasospasm. Multiple aneurysms can sometimes be found in order to plan surgical approaches and procedures. 3. Perform a detailed physical examination to estimate the patient's ability to withstand surgery. 4. Relieve the patient's fear of surgery, and give sedatives before the operation to prevent the patient from rupturing due to preoperative emotional stress. 5. Wash the scalp one day before the operation, shave the hair on the morning of the operation, wash and disinfect the scalp, and wrap it in a sterile towel. 6. Prepare for blood transfusion and give antibiotics to prevent infection. Surgical procedure Anesthesia and position With general anesthesia, the induction period should be rapid and stable. The blood pressure is controlled to a normal low level at the beginning of the operation. The mean arterial pressure was reduced to (70-80 mmHg) with the drug when the aneurysm was removed and the neck was clamped. For the elderly and those with high blood pressure, the blood pressure should not be too low. Otherwise it can cause cerebral ischemia. The patient takes the supine position, the head is biased to the opposite side by about 45°, and slightly sag 20°, so that the condyle is at the highest point, so that the frontal lobe of the brain is drooped off the dome due to natural gravity, reducing the pulling force and facilitating the visualization of the artery. tumor. The head frame is fixed with a three-claw skull to maintain the head in this position. Surgical procedure 1. The surgical approach Wing point approach. 2. Exposing an aneurysm Since the position of the aneurysm is posterior, the lateral fissure must be more widely separated. Especially when the internal carotid artery segment is long, the frontal lobe needs to be more retracted to reveal the bifurcation of the internal carotid artery. The carotid artery pool, the optic chiasm and the endplate pool were fully opened, and the internal carotid artery was separated backward and exposed to the bifurcation of the internal carotid artery. Yasargil believes that there are three reasons for fully opening the endplate pool: 1 when lifting the frontal lobe, it may pull the arachnoid strap across the anterior cerebral artery, so as to block its blood flow and transmit the traction force to the aneurysm; Before the aneurysm is clipped, the Heubner return artery and some perforating arteries must be identified. 3 In order to fully expose and clip the aneurysm, it is sometimes necessary to consider sacrificing the A1 segment of the anterior cerebral artery. Only the open endplate can be seen clearly. The size of the A1 segment of the anterior cerebral artery and the collateral circulation through the anterior communicating artery are sufficient for decision making. The Heubner return artery is emitted in the anterior communicating artery region, and is located laterally behind the anterior cerebral artery. It may be located above or under the aneurysm. Multiple arteries are present in the A1 and M1 segments before the neck is clamped. It must be separated from the neck. The internal carotid artery bifurcation aneurysm is sometimes partially or completely embedded in the parenchyma of the frontal lobe, and the pia mater must be cut open to remove some of the brain tissue to reveal the aneurysm. In this case, lifting and pulling the frontal lobe must be very gentle to avoid tearing the aneurysm. 3. After clamping the aneurysm and separating the neck, select the appropriate tumor clip to clamp the neck. The tumor clip is preferably parallel to the A1 and M1 segments and slowly clamped when it is confirmed that the important perforating artery is not included. complication 1. Cerebral infarction. Damage caused by the artery. 2. Tumor neck clipping is incomplete or tumor clip slippage causes rebleeding. In this case, the operation can be considered as a failure, and surgery should be performed at an appropriate time. 3. Intracranial hematoma. The incidence is about 0.9%, CT is easy to diagnose and needs to be removed again. 4. Other. Infection, epilepsy, hydrocephalus, etc., take appropriate measures.