Initial placement: 1.The right internal jugular vein is preferred for placement, and if there are restrictions, the left internal jugular vein is second choice for placement. 2, Ultrasound-guided puncture or ultrasound-localized puncture, X-ray fluoroscopic imaging and placement Zhu Renming, Department of Vascular Surgery, Beijing Friendship Hospital, Beijing, China Puncture site selection: low puncture or medium-low puncture of the internal jugular vein is recommended. 3.After local anesthesia, the right internal jugular vein is punctured, and after successful puncture, the guidewire is implanted. Fluoroscopic observation of the advancing guidewire, paying attention to the morphology of the head end of the guidewire, which usually enters the right ventricle, but also enters the inferior vena cava, and occasionally is seen retrograde into the left innominate vein. 4. Retain the guidewire, withdraw the puncture needle, implant the vascular sheath, and perform superior vena cava and right atrial angiography to confirm the ideal position of the catheter head end. Mark the target position, 1 hemostatic forceps can be placed to mark the position. 5.Take the long-term catheter, coincide the head end with the ideal position of the hemostat marker, and design the subcutaneous tunnel alignment and tunnel skin opening position according to the location of the puncture point, CUFF position. 6.Cut the skin of the venous puncture site about 2cm and separate the subcutaneous tissue. 7.After local anesthesia to tunnel the subcutaneous tissue in the alignment area and tunnel the skin incision, implant a tunneler to make a subcutaneous tunnel and lead the long-term catheter to the skin incision at the puncture site. Pull out the long-term catheter through the skin incision at the puncture point to the CUFF segment. 8.After pre-dilator expansion, implant the avulsion sheath and large dilator, taking care not to use violence to avoid deformation of the avulsion sheath, and implant the dilator and avulsion sheath under fluoroscopy throughout. 9.After the patient stops breathing, withdraw the large dilator and rapidly implant the long-term catheter, paying attention to the arterial end of the catheter pointing to the midline position of the superior vena cava as much as possible. 10.After implantation of sufficient length, fluoroscopy confirms that the avulsion sheath is torn open and the catheter is implanted at the same time. After the avulsion sheath is completely torn open and pulled out, the catheter is mostly implanted in the body and the CUFF is located in the incision. 11.Adjust the position of the proximal end of the catheter under fluoroscopy, which can create a subcontrast to clarify the position, and then observe the catheter neck alignment under fluoroscopy to ensure no distortion. 12.After determining the position, suture the puncture point incision, which must be 2 layers (subcutaneous layer and skin layer) taking care that the catheter is not twisted and the suture needle does not damage the catheter. 13.The subcutaneous tunnel opening should also be fixed with sutures to prevent the patient from inadvertently causing the catheter to come out, which can be done by suturing the skin and then suturing around the loop to fix the catheter. 14, The end of the catheter and the skin are sutured and fixed. 15.Finally, take heparin saline to repeatedly flush the catheter double lumen, confirm patency, and heparin seal the catheter. Sterile dressing covers the wound at the suture and the end of the catheter. Temporary replacement of long-term catheter 1.After thorough local disinfection, unscrew the temporary catheter, withdraw the blocked heparin and implant the guidewire, and confirm that the guidewire is located in the right atrium or inferior vena cava under fluoroscopy. 2.Exit the temporary catheter and disinfect thoroughly again. 3.Take the skin of the puncture site 2cm near the heart and make an incision, about 2cm, through which the guidewire is separated to expose the guidewire and the distal end of the guidewire is raised through the incision. It must be ensured that the proximal end of the guidewire is not displaced. After cleaning and disinfecting the guidewire again, the vascular sheath is implanted and the position of the head end of the long-term catheter is confirmed by imaging. Marking with hemostatic forceps. The following is the same as the initial placement.