Many patients are reluctant to undergo surgery because they have the question, “How will the blood flow back after the vein is cut out?” The question. In fact, there are many traffic branches between the deep and superficial veins of the lower extremities, and between the large and small saphenous veins, and the blood can still flow back to the deep veins and finally to the heart through other channels after the surgery has blocked some of them, so there will not be no blood flow back. Injection therapy is the sclerotherapy that was used in the 1950s and 1960s. The so-called “one shot” and “one time cure” actually involves injecting drugs into the blood vessels, causing sterile inflammation and necrosis of the vein lining with the drugs, and then compressing the walls of the injected blood vessels by pressing them locally, causing the walls to adhere and eventually make them This method is seemingly simple and effective. This method seems simple, but the results are unreliable and prone to complications. Many patients are left with painful streaks, thrombophlebitis, deep phlebitis and thrombosis after the injection. The outstanding disadvantage is that it does not completely, effectively and permanently block the refluxed blood from the high trunk vein, as in radical surgery, and thus has a high recurrence rate, as has been proven in medical practice both nationally and internationally. This method is particularly limited for patients with capillary dilatation, reticular veins, or small varicose veins less than 4mm in diameter, as well as for patients with postoperative recurrence who are unwilling or unable to undergo surgery.