Step 1: Push the suction catheter to the proximal end of the thrombus

　　Push the suction catheter forward so that the distal marker is located at the proximal end of the thrombus.

　　(Note: the pushing speed should not be too fast, and the hand-held suction catheter should not be too tight)

　　Step 2: Start thrombus aspiration from near to far

　　1. Open the plug valve on the extension line to start pumping;

　　2. Maintain sufficient negative pressure, slowly send the suction catheter forward, and slowly withdraw the suction catheter until it reaches the distal predetermined position until it reaches the proximal end of the thrombus. If necessary, the forward and backward pumping operations can be repeated;

　　3. If the amount of blood pumped has reached half of the syringe capacity, the cock valve should be closed to replace the syringe before pumping again.

　　(Note: Negative pressure refers to keeping 15-20mL of air in the syringe)

　　Step 3: withdraw the suction tube with negative pressure

　　After the suction is completed, keep the negative pressure state and slowly withdraw the suction catheter to the guide catheter, and then quickly withdraw the suction catheter from the guide catheter.

　　Step 4: Evaluate the suction effect

　　After the suction catheter is withdrawn from the body, inject the blood in the syringe and suction catheter and the blood returned by the finger guide tube into the filter screen. After washing, observe the shape, size and color of the aspirates. Combined with coronary angiography again and TIMI blood flow, decide whether to aspirate again.