As with most surgical procedures, varicose veins have a recurrence problem after surgery. So, what are the causes of recurrence? What can be done to prevent them? What can be done if a recurrence occurs? The following is a preliminary introduction to these questions: The factors that lead to the recurrence of varicose veins are complex, and the following are common: The first condition is the residual of the postoperative geniculate branch. Some patients find that there are still varicose vein clusters on their legs just after the surgery, which means that they are “not clean”. In other words, the patient’s focus is on the varicose vein mass on the surface of the leg, while the doctor’s focus is on the deep saphenous vein trunk, because the “root” of varicose veins is the saphenous valve lesion at the root of the thigh. During the surgery, the doctor is more concerned about whether the root of the saphenous vein is treated and whether the trunk is completely treated, sometimes the small varicose masses on the surface of the leg are ignored and not treated, so of course there is a residual situation; in addition, varicose veins are only obvious when standing, but when lying down to do the surgery it is not clear and easy to miss. To prevent this, it is necessary for the surgeon to carefully observe the varicose veins on the surface of the patient’s legs before the surgery. Our method is to have the patient stand in a well-lit place the day before or the morning of the surgery, and to trace the varicose masses or single blood vessels on the surface of the legs with purple potion or a marker, and to treat the traced areas accordingly during the surgery. This treatment can largely prevent missing, or “branching residuals” after surgery. We perform 200-300 varicose vein surgeries each year, and the incidence of this condition is about 1%. If this happens, it can be easily dealt with by tracing the residual branches and then using laser cautery for a few minutes under local anesthesia, and this remedy can be done on an outpatient basis without the need for hospitalization. The second situation is that the surgery is done cleanly and all the original varicose veins are gone, but after some time (months to decades) the varicose vein masses appear again on the legs, even worse than the original ones in a few cases, which is a real relapse for several reasons: (1) The root of the saphenous vein is not ligated accordingly, or the main branches of the root of the saphenous vein are not ligated. Anyone who has ever consulted me knows that the root of saphenous varicose vein is in the saphenofemoral valve at the root of the thigh. If the vessel is simply treated by various methods (e.g., sclerotherapy injection, simple laser treatment, simple removal of the vein mass, etc.) without ligating the valve, then it is bound to recur, only a matter of time. The way to prevent it is to always ligate the femoral-saphenous valve at the root of the thigh as well as the main geniculate branch at the root. This presents a contradiction: many patients require “minimally invasive”, that is, as scarless as possible, mainly some young female patients are more demanding; while high ligation is necessary to make an incision at the root of the thigh. In order to solve this contradiction, I have improved the incision of high ligation since 2006, changing the original vertical incision of about 6~8cm long to an oblique incision of about 2cm long, which is hidden in the skin folds at the root of the thigh and is not easily detectable. The contradiction between reducing recurrence and minimizing invasiveness has been basically solved. We started laser treatment of the saphenous vein in 2003 under the guidance of British specialists, and abandoned the traditional high ligation (same as the British method) in order to emphasize “minimally invasive”. More than one thousand cases have been treated so far, and the recurrence rate is controlled to less than 5%. Therefore, I emphasize: the method of saphenous vein surgery is the same: it must firmly ligate the femoral-saphenous vein valve and the main branches of the root. If there is a recurrence due to this cause, a retroactive high ligation is needed to solve it. (2) The diseased traffic branch vein was not treated during the surgery; or the traffic branch vein was not a problem at the time of the surgery, but some time later the traffic branch vein developed a problem again, causing a recurrence. I will explain it in layman’s terms: the venous return of lower limbs depends on 2 systems: deep vein and superficial vein, of which the deep vein plays the main role (85-90%), so if the superficial vein (saphenous vein) is diseased, it can be ligated and surgically removed without affecting the return flow. But the two systems of deep and superficial veins are not isolated, there are some small communication branches between them, which is like a “canal” between two rivers, and this canal also has a gate, which is a valve. When there is a problem with the valves of these communication branches, it will also cause superficial varicose veins. Moreover, although these canals are small, once the valves fail, they are very harmful and are the direct culprits of “polyposis” and “old rotten leg”. However, most doctors and patients do not realize this, and simply treating the diseased superficial veins without treating the diseased traffic branch veins is one of the major causes of recurrence. Prevention can be achieved by carefully checking the function of the traffic branch veins before the surgery, marking them and ligating them during the surgery; and it should be realized that: it is not done once and for all after the varicose vein surgery, and it is important to protect your legs from further damage of the traffic branch veins. If there is a recurrence due to this reason, a retroactive traffic branch ligation will be done. (3) Anatomical abnormalities. This is very rare, and we have dealt with three such cases (both those who had surgery in our hospital and those who had it done in other provinces): the surgery was performed according to the standard operation, but there was a recurrence after the surgery, and when we saw them again we did a venogram and found that the saphenous vein originally treated surgically disappeared, but a new saphenous vein appeared next to it, anatomically called “para-saphenous vein”, which was cured by another operation. (4) There is a problem with the deep vein. This is a question of indications and, in layman’s terms, whether such patients should have varicose vein surgery or not. I have briefly mentioned this issue in my previous scientific articles: when there is a suspicion of deep vein problems, further detailed examination should be done, and in some cases, varicose vein surgery should not be done, and the results will not be good even if it is done; in some cases, it is necessary to deal with the deep vein lesions at the same time when doing varicose vein surgery to ensure the results. In conclusion, varicose vein surgery is a minor surgery and many doctors are capable of treating this disease. However, a more comprehensive understanding of this disease is needed to make it more precise and detailed. I believe that with the joint efforts of everyone, the surgical efficacy of this disease will become better and the recurrence rate will become lower and lower.