Palmar hyperhidrosis is an unexplained condition of abnormal hand sweating caused by sympathetic hyperactivity that is not affected by external temperature. The treatment of hand sweating has long been a difficult problem, and although many treatments have been available, they are often ineffective. In recent years, thoracic sympathectomy under VATS has been reported as a minimally invasive and safe procedure for the treatment of hand sweating, and has been promoted. From February 2005 to February 2012, 63 cases of hand sweating were treated by bilateral T3-4 sympathetic nerve chain dissection with TV thoracoscopy with satisfactory results. 1. Clinical data 1.1 General data Among the 63 cases in this group, 37 were male and 26 were female. Age ranged from 16 to 45 years old, with a mean age of 22.6 years. All of them presented with the complaint of sweaty palms, and in severe cases, the sweating of both hands was in the form of dripping beads. There were 6 cases of grade I mild (moist), 18 cases of grade II moderate (dominant sweating with sweat drip), and 39 cases of grade III severe (sweat drip), totaling 63 cases. After admission, medical history was carefully inquired and relevant examinations were done when necessary to exclude hyperthyroidism or other diseases causing generalized sweating, and electrocardiogram, chest X-ray or CT, and routine blood sampling and laboratory tests were routinely done before surgery. 1.2 Surgical method General anesthesia with double-lumen tracheal intubation, intraoperative monitoring of vital signs and palm temperature. In a 45° semi-sitting position with both arms abducted at 90°, two small 12.5px incisions were made in the 1st intercostal space in the midclavicular line and the 3rd intercostal space in the anterior axillary line for observation and operation holes. At the same time, the cut was extended 1.5 to 50 px outward along the rib to cut the possible traffic nerve bundle (kuntz bundle). A temporary chest drain (pediatric catheter or infusion tube with lateral holes) is left in the observation hole at the end of the procedure and connected to a water-sealed cup or negative-pressure suction, which is withdrawn at the same time as the cholka after adequate expansion of the lung. Two small incisions are made without sutures, and a sterile patch is applied after skin alignment. The contralateral surgery is performed in the same way. 1.3 Postoperative management Chest X-ray was taken on the first postoperative day to understand whether there was hemopneumothorax or pulmonary insufficiency, and ECG was reviewed to compare the QT interval values before and after surgery. Prophylactic antibiotic treatment was given for 24 hours, no postoperative pain relief was required, and the patient could be discharged on the 2nd to 3rd day after surgery. 1.4 Efficacy assessment criteria Postoperative palm skin temperature of the affected hand increased by 1~3℃ or higher than that before surgery, and those who turned dry were considered effective. Those whose palm skin temperature increased <1< span="">℃ compared with that before surgery or remained moist were considered ineffective. 1.5 Results Intraoperative oxygen saturation and electrocardiographic monitoring did not show significant changes in all patients in this group, and the surgery was completed successfully under lumpectomy. The average operation time was 31 min. There was no case of serious complications such as hemorrhage, arrhythmia and cardiac arrest during the operation, and there was no case of intermediate open heart or surgical death. There was no case of Horner’s syndrome, bradycardia, or hemothorax after surgery. Postoperative complications included a small amount of pneumothorax (all less than 20%) in 2 cases (3.2%), a small amount of subcutaneous emphysema in 3 cases (4.8%), hidden pain in the chest and back in 19 cases (30.2%), dry skin on the palms of the hands in 10 cases (15.9%), and excessive sweating on the back and soles of the feet in 11 cases (17.5%). All patients’ symptoms were significantly relieved or disappeared, among which 31 of 39 severe patients’ palms were obviously turned dry and 8 were slightly moist; 24 mild to moderate patients’ palms were all turned dry; all 63 cases’ palm temperature increased ≥1.5-3.0℃, and the efficiency rate was 100%. Postoperative recovery was smooth, and 2-3d were discharged from the hospital. Normal study or work resumed 1 to 2 weeks after discharge. The postoperative follow-up time was 1.5 to 28 months, and there was no case of recurrence. 2. Discussion Anatomical studies have found that hand sweat activity is innervated by the thoracic sympathetic chain, the center of which is located in the 2nd to 6th spinal cord segments. The treatment of primary hand sweating includes surgical and non-surgical therapies. Non-surgical therapies include astringents, antiperspirants, sedatives and anticholinergic drugs, but they have little efficacy and are not long lasting. The mechanism of thoracic sympathetic nerve chain dissection for hand sweating is mainly by cutting or excising the thoracic sympathetic nerve chain and blocking the distribution of the postganglionic fibers emanating from it to the skin sweat glands innervated by the nerves in the upper limbs, which is considered to be the only effective treatment for hand sweating at present [5-6]. 2.1 Indications for surgery (1) Moderate or higher cases of primary hand sweating with a long course of ineffective or recurrent medical treatment that significantly affects the patient’s daily life and work. (2) Secondary hyperhidrosis caused by central nervous system diseases, hyperthyroidism or hypermetabolism, neuroanxiety disorders and other underlying diseases have been excluded. (3) Those without pleural and pulmonary lesions by chest x-ray or CT examination. A previous history of thoracic surgery or a heart rate <60 beats/min is a contraindication to surgery. < span=""> 2.2 Superiority of TV thoracoscopic thoracic sympathectomy Traditional open-chest surgery is traumatic, has many complications, and affects function and aesthetics, making it difficult for most patients to accept. The emergence of TV thoracoscopy has completely changed the status quo of hand sweating treatment, which has the advantages of small trauma, accurate positioning, safety and reliability, fast postoperative recovery, few complications, and exact and long-lasting curative effect. This group applied 12.5px small incision, which is more traumatic and hidden, in line with the requirements of minimally invasive surgery, and the patients are happy to accept it. 2.3 The range of thoracic sympathetic nerve chain severance There are different reports, and it has been confirmed that sympathetic nerve chain severance with T2 to 3 and T3 to 4 can effectively treat hand sweating [7]. A large number of experimental and clinical data prove that the majority of sympathetic innervation in the hand comes from the T2 to T4 segments. Liu Yanguo et al [8] concluded that lower single-site T3 and T4 sympathectomy is definitely effective in hand sweating, with an efficiency rate of 100%, but T4 sympathetic chain dissection significantly reduces the occurrence of surgical side effects and keeps the patient’s palm in a slightly moist state after surgery, like a state close to normal, which is more recommendable. We used T3 and 4 sympathetic nerve chain severing, while extending the severing area 1.5-2.0 cm outward along the rib surface to sever the possible traffic nerve bundle (kuntz bundle), with exact efficacy and 100% efficiency, and the incidence of compensatory sweating after surgery was 11/63 (17.5%), without a single case of Horner syndrome, with simple intraoperative operation, short operation time, and The operation is simple, the operation time is short, and the result is definite. 2.4 Prevention and treatment of complications Surgical complications are generally mild and few. (1) Pneumothorax and subcutaneous emphysema: the methods of prevention include routine placement of closed chest drainage after surgery, placing a catheter in the incision for exhaustion and negative pressure suction or connecting a water-sealed cup, and removing it after adequate lung expansion. We used catheter venting and parallel negative pressure suction, and the anesthesiologist fully inflated the lung and maintained positive airway pressure for a few seconds and then extracted it at the same time with cholka, with good results. There were only 2 cases of pneumothorax and 3 cases of subcutaneous emphysema in this group, all of which were absorbed by themselves without special treatment. (2) Bleeding: The common reason is that the odd vein or intercostal vessels are close to the sympathetic nerve chain, and the vessels are accidentally injured when cutting the nerve, which is seen on the right side than the left side. In addition, bleeding is also seen when the lung tip is free of adhesions. We use segmental cut of T3 or T4 sympathetic nerve chain to avoid injury to the vessels, and electrocoagulation or titanium clamps can be used to stop small bleeding during surgery. Bleeding can be completely prevented by fine surgical operation and moderate movements, and there were no bleeding complications in this group. (3) compensatory hyperhidrosis: this is a problem that has been consistently explored for more than 60 years since the first creation of this procedure, and it is also the most common complication that brings new troubles to patients, with an incidence of 30% to 75% reported in the literature [9], the mechanism of which is not known. In recent years, some scholars have taken to reduce the extent of sympathetic chain resection or lower the severed segment can significantly reduce the occurrence of side effects such as compensatory sweating. We routinely cut the T3 or T4 sympathetic chain, and l1 cases (17.5%) in our group had different degrees of compensatory hyperhidrosis in the back and foot after surgery, which is lower than those reported in the literature, and most patients had mild symptoms that gradually resolved without special treatment. (4) Horner’s syndrome: It is the most serious complication due to direct or indirect injury to the stellate ganglion resulting in ipsilateral pupil narrowing, eyelid ptosis, eye entropion and facial anhidrosis. We believe that the key lies in the accurate intraoperative localization of the T2 sympathetic nerve trunk and the correct treatment of the sympathetic nerve trunk. Firstly, the highest position of the thoracic apex can often be seen in the 2nd rib, and the 1st rib is often covered by yellow adipose tissue and cannot be seen. Second, the operation with electrocoagulation should be performed quickly and precisely to minimize heat conduction damage to the stellate ganglion. In conclusion, TV thoracoscopic thoracic sympathetic nerve chain dissection for primary hand sweating can replace the traditional open-chest surgical approach, which is less traumatic, has fewer complications, is simple to perform, has a quick recovery, has a small scar, is easily accepted by patients, and is clinically worth promoting.