The artery is opened and gentle pressure is applied to stop the bleeding. There should be immediate pulsation in the vein and catarrh can be palpated, indicating patency of blood flow and completion of the arteriovenous fistula bypass. Croup is also called dry rales (wheezes,rhonchi). (Croup is a type of dry rales.) Croup occurs when bronchial asthma attacks. The pathological basis of airway narrowing or incomplete obstruction includes inflammation-induced mucosal congestion and edema and increased secretions, spasm of bronchial smooth muscle, obstruction by intraluminal tumors or foreign bodies, and narrowing of the lumen caused by compression of the wall by extra-tubular enlarged lymph nodes or mediastinal tumors. It is seen as a possible cause of bronchial asthma, bronchitis, pneumonia, bronchial asthma, etc. Catarrhal wheezing can be treated by extracorporeal arteriovenous bypass. It can be used for a longer period of time, easy to operate and does not require puncture; however, it is prone to embolism in the distant future, with catheter, less convenient life, easy bleeding and infection. 1.Incision and exposure: Make a longitudinal incision of about 2 cm in length at the place where the pulsation of the radial artery is obvious 5 cm above the forearm wrist joint, cut and separate the subcutaneous tissues and fascia, reveal a 2 cm long section of the radial artery, and tract it with a silk thread. A small incision of about 2 cm was made at the superficial vein adjacent to the radial artery, and the subcutaneous tissue was incised and separated to reveal the subcutaneous vein, which was separated by about 2 cm, and traction was applied with a silk thread. (1) The ends of the radial artery are separated and traction is applied with a silk cord. (2) Lift the traction wire, block the blood flow, and make a small incision in the arterial wall. 2. Trial fitting of silicone shunt catheter: Cut and separate the subcutaneous tissue so that the curved part of the silicone shunt catheter can be buried satisfactorily. After fitting the silicone arteriovenous shunt catheter, the lumen is filled with heparin solution (50mg/ml) and the end of the catheter is clamped. (3) The arteriotomy wall is drawn away with a nylon wire. (4) Insert the shunt catheter into the radial artery. 3.Placement of the arterial catheter: The distal end of the radial artery is first ligated, and the proximal end is lifted with a traction wire to temporarily block the blood flow. A small incision is made in the wall of the radial artery, and the two walls are drawn apart with nylon silk thread. The silicone shunt catheter is inserted into the radial artery, and the silicone shunt catheter is ligated and secured to the vessel wall with a silk ligature. The U-shaped portion of the silicone shunt catheter is buried within the subcutaneous tissue of the submarine separation, and a small incision is made in the skin at the appropriate location to drag out the end of the silicone tube. (5) The catheter is secured to the vessel wall with a silk ligature. (6) Bury the U-shaped catheter in the subcutaneous tissue. 4.Placement of venous catheter: Ligate the distal end of the separated vein and lift the proximal end with silk traction to block the blood flow. A small incision is made in the vein wall and another silicone shunt catheter is inserted into the vein and heparin saline solution is injected into the catheter and observed for patency. In the same way as for the artery, the U-bend portion of the catheter is buried in the subcutaneously separated subcutaneous tissue, and the catheter is dragged out of the skin by poking holes at appropriate locations. 5.Connect the catheter and suture: After confirming that both the arterial and venous shunts are patent, the two tubes are connected and the arterial blood is seen to flow into the vein, pulsation can be palpated at the proximal end of the vein, and murmurs and catarrh sounds are auscultated, indicating that the blood flow is patent. The skin incision was closed with silk sutures and lightly wrapped with a dressing.