Thoracic sympathectomy is a classic procedure for the treatment of hand sweating, but the incidence of compensatory hyperhidrosis after surgery can be as high as 85%, with severe compensatory hyperhidrosis occurring in 15% of cases, which has become a major factor in patients’ reduced satisfaction with the procedure and regret undergoing it. Although various methods have been tried to treat compensatory hyperhidrosis, such as oral gastric longing, injection of botulinum toxin, and even the use of transcutaneous electrical stimulation, none of them have achieved definite results. In this paper, good results were achieved by using CT-guided lumbar sympathetic nerve block to treat compensatory hyperhidrosis after ETS, which is reported as follows. 1. Clinical data and methods 1.1 Subjects: After approval by the hospital ethics committee and obtaining informed consent from patients, 7 patients with compensated hyperhidrosis treated with CT-guided lumbar sympathetic block between April 2011 and October 2011 were used as observation subjects: male/female (4/3), age 23~41 years, average 27.57±6.21 years, history of compensated hyperhidrosis 2 months~12 All 7 patients had undergone transthoracoscopic thoracic sympathectomy for primary hand sweating and developed severe compensatory hyperhidrosis after surgery, manifesting as excessive sweating below the nipple level, especially in the lower back, both lower extremities, and perineal area, with sweat dripping when the temperature was higher than 25°C or when the above areas were slightly moved, requiring underwear to be changed several times a day and seriously affecting work life. 1 patient had gone to a hospital in Taiwan to undergo nerve transplantation. One patient had gone to a hospital in Taiwan for nerve transplantation, but the result was not good. The rest of the patients had tried oral Chinese medicine or topical application, but no effect was seen. 1.2 Methods: After the preoperative blood tests, prothrombin time, positive and lateral lumbar spine films, and electrocardiogram were normal, the patients and their families were given a detailed explanation of the operational characteristics and expected effects of the “CT-guided lumbar sympathetic nerve block” technique, as well as possible complications, and written approval was obtained from the hospital ethics committee and the patient’s signed informed consent was obtained. The patient was asked to lie prone on the CT table, and the patient’s electrocardiogram (ECG), noninvasive blood pressure (NIBP), finger pulse oxygen saturation (SPO2) and palmar temperature (T) were monitored and recorded. The needle was inserted at the established depth and angle guided by the CT positioning puncture guide until the needle tip reached the anterolateral aspect of the lumbar 3 vertebral body and the anterior lumbaris major muscle after injecting 3 ml of local anesthetic 1% lidocaine containing contrast agent iohexol on each side and observing the distribution of the drug in the anterior lumbaris major muscle, and the temperature of both feet rose significantly, then 5 ml of anhydrous alcohol containing contrast agent was injected on each side and the flow of anhydrous alcohol was observed by CT scan again. After the operation, the patients were observed on the second day, the first week, the first, third, sixth and eighth months for efficacy and complication follow-up. 2 , Results Seven patients with 14 lateral lumbar sympathetic nerve block punctures were successfully punctured to the target site under the guidance of CT localization puncture guide. After injection of local anesthetic, CT scan showed that the drug was distributed laterally in the lumbar 2/3 vertebral body and anteriorly in the lumbar major muscle. 5 min after drug injection, the temperature of both feet of the patients increased significantly, and the average increase in the palm temperature was 4.35±1.63℃, and there was no significant change in heart rate and blood pressure. After injecting 5ml of anhydrous alcohol, the drug was more widely distributed and could spread to the anterolateral aspect of the lumbar 2/3 vertebrae and the anterior aspect of the psoas major muscle. After the operation, the patient felt warm below the lumbar back and both lower extremities. On the second day, the first week, the first, third and sixth month, the patient was followed up and sweating decreased between chest 4 and chest 7, and sweating stopped below the plane of chest 7, and no related complications occurred. 3 , Discussion Compensatory hyperhidrosis, also known as metastatic hyperhidrosis, is a common complication after thoracoscopic thoracic sympathetic nerve chain dissection for hand sweating. Although different segments or methods of thoracic sympathetic nerve resection have been explored to reduce the incidence of postoperative compensatory hyperhidrosis, a multicenter survey found that the incidence of severe compensatory hyperhidrosis after thoracic sympathectomy was still as high as 15%. The mechanism is that the lower sympathetic chain (lumbar sympathetic chain) loses the downstream inhibition of the hypothalamic sweating center after complete severance of the thoracic sympathetic chain, which leads to a state of uncontrolled sweating in the lower body. The lack of a simple and effective treatment for postoperative compensatory hyperhidrosis has greatly limited the clinical promotion of this procedure, and even some countries or regions have had to restrict or stop thoracoscopic thoracic sympathectomy for hand sweating. If the lumbar sympathetic chain is cut off again, the sweating of the lower body can be effectively stopped, but the consequence of no sweating of the whole body is quite serious: once the patient completely loses sweating function, 80% of the heat dissipation ability will be lost, and the hot environment will easily lead to heatstroke, so it is unrealistic to rely on lumbar sympathetic chain excision to treat compensatory hyperhidrosis. When we performed lumbar sympathetic block for lower limb occlusive vasculitis, we found by chance that the sweating of the lower back and lower limbs was significantly reduced or even absent after lumbar sympathetic block, and our previous thoracic sympathetic nerve modulation technique had achieved good results in the treatment of Raynaud’s disease and hand sweating. The technique of lumbar sympathetic nerve modulation for compensatory hyperhidrosis is to inhibit the excessive activity of the lumbar sympathetic nerve chain without destroying the anatomical structure of the nerve chain by injecting a small amount of neuromodulator under CT guidance to denature some of the nerve fibers, thereby inhibiting excessive sweating while preserving its normal sweating function under high temperature. There is no need to worry about the risk of heat stroke in patients, and it is expected to be a safe and effective treatment for postoperative compensatory hyperhidrosis. Of course, due to the small sample size of this group and the fact that the follow-up period of this group is not long enough, further follow-up is needed to evaluate its long-term efficacy.