The procedure should be performed in a sterile surgical gown after sterilization and hand brushing. 2.Seldinger arterial cannulation technique: after routine disinfection and towel laying, perform femoral artery puncture under local anesthesia (the puncture point is 1.5~2cm below the inguinal ligament where the femoral artery pulses most clearly), see blood ejected after pulling out the needle core, gently push the puncture needle along the arterial lumen for 1~2cm, introduce the guiding wire and then withdraw the puncture needle, send the catheter sheath (containing the dilatation tube) through the guiding wire, the catheter sheath After fixation, the guiding wire and dilator tube are pulled out together. The catheter is inserted through the catheter sheath (the catheter is filled with heparin saline), and the catheter is fed into the left and right internal and external carotid arteries and the vertebral artery under fluoroscopy (the artery can also be inserted according to the specific requirements), and a small amount of contrast is injected to confirm the location of the catheter tip. 4. Connect the catheter to a high-pressure injector for imaging and radiography. 1. The entire contrast catheter system must be airtight (pay attention to the evacuation of air bubbles) and connected to a saline pressurized flushing device for continuous flushing to prevent thrombosis of the internal and external walls of the catheter. 2. Every 10-15 minutes, flush the catheter lumen with 1:25 heparin solution. For patients with severe atherosclerosis, longer operation time and coaxial catheter system, systemic heparinization should be performed (3000u-5000u at the beginning of the procedure by one-time intravenous push; then 1000u-2000u every hour by intravenous push) to prevent thrombosis. Measure coagulation every 1 hour if necessary to adjust the amount of heparin. Neonatal and post-surgical patients do not need systemic heparinization. 3, selective imaging, the operation of the catheter should be gentle, fast and slow, in case of resistance or unknown, a small amount of contrast should be injected under fluoroscopy to make a clear judgment, for those with severe atherosclerosis or congenital or acquired abnormalities, aortic arch imaging should be done to understand the opening of the carotid artery, vertebral artery and possible abnormalities, do not forcefully force, resulting in complications such as intimal tearing and atheromatous plaque detachment. After contrast injection, routine frontal and lateral views are taken, and special angles such as left and right oblique views can be added if necessary. 2.For patients with intracranial aneurysm, four angiograms (bilateral internal carotid arteries and bilateral vertebral arteries) should be performed; for patients with arteriovenous fistula, six angiograms (plus bilateral external carotid arteries) should be performed. 3. Neck compression test: Compress the affected carotid artery and perform contralateral internal carotid artery and vertebral artery angiography to understand the function of anterior and posterior communicating arteries. It is used to assess the cerebral collateral circulation in patients with intraoperative temporary occlusion of the affected internal carotid artery. 4.Balloon occlusion test (BOT): temporarily occlude the affected internal carotid artery with a non-detachable balloon for 20 minutes, observe the patient’s clinical response and perform SPECT examination to assess the compensatory function of cerebral collateral circulation in patients with temporary or permanent intraoperative occlusion of the affected internal carotid artery. Postoperative management】 1. The arterial puncture site was adequately compressed to stop bleeding (usually 10-15 minutes), and local pressure bandages were applied for 24 hours after the bleeding stopped. In patients with systemic heparinization, neutralize the ratio of ichthyosperm sulfate (mg) to residual heparin (u) in the body 1:100, and then pull out the sheath after 15 minutes to stop the bleeding by compression, as before. Caviar sulphate should be diluted with saline 10ml and then injected slowly intravenously for more than 10 minutes. If an allergic reaction occurs, immediately treat with dexamethasone 10mg intravenously. 2. In patients with intraoperative systemic heparinization, postoperative coagulation function (PT, KPTT) is routinely and urgently checked, and the medication and continued monitoring are adjusted according to the specific situation. If KPTT is more than 2 times the basal value, apply 20-35mg of fisetin sulfate; if it is more than 2 times the basal value or less, use 10-20mg of fisetin sulfate; for patients who need to continue systemic heparinization after surgery, keep KPTT between 2 and 3 times the basal value. 3.Brake the lower limb on the puncture side for 24 hours. 4.Measure blood pressure Qh ′ 2 times and Q2h ′ 2 times. 5.Dorsalis pedis artery pulsations of the lower limb were measured Q1/2h ′8 times. 6.Dexamethasone 5mg i.m. Qd ′ 3 days. 7.Lincomycin 0.6 i.m. Qd ′ for 3 days. 8.Low molecular dextrose 500mL i.v.gtt. Qd ′ 3 days (may be used as appropriate).