[Abstract] Objective To investigate the feasibility of laparoscopic cold circulation radiofrequency ablation for renal cell carcinoma. Methods Laparoscopic cold-circulation radiofrequency ablation was selectively performed for 13 times in 12 renal cancer patients. The tumors were located in the left kidney in 4 cases, the right kidney in 7 cases, and both kidneys in 1 case. The maximum tumor diameter ranged from 2.1 to 8.5 cm, including 11 cases of T1N0M0 and 2 cases of T2N0M0. Postoperative CT and ultrasonography were used for regular follow-up. Results The mean operative time was 92±24.5 min, the mean bleeding volume was 50±28.8 ml, and none of them had intraoperative blood transfusion. No complications related to laparoscopic surgery were observed. Of the 13 renal cancer lesions at 6 weeks postoperatively, 12 were completely ablated and 1 was incompletely ablated, with a complete ablation rate of 92.3% (12/13). There was no significant change in hemoglobin, erythrocyte sedimentation rate, blood creatinine, and affected ECT-glomerular filtration rate compared with those before surgery (P>0.05). CT review data were obtained in 10 patients at 3 months; 9 cases had complete necrosis of the lesion and 1 case had partial necrosis of the lesion. There were no cases of local and distant recurrence. The follow-up time ranged from 1 to 16 months, with a median of 7.8 months, and all 12 cases survived. Conclusion Laparoscopic cold circulation radiofrequency ablation is a new and safe and effective method for the treatment of renal cancer. It is more precisely localized than ultrasound-guided radiofrequency treatment and can be applied to cases that are not suitable for ultrasound-guided percutaneous renal puncture radiofrequency ablation. 【Key words】 Cold circulation electrode;radiofrequency;laparoscopy;renal cell carcinoma Cold circulation radiofrequency is a new treatment technique developed on the basis of traditional radiofrequency. Laparascopic cool-tip radiofrequency ablation (LCRFA) is more accurate than ultrasound-guided radiofrequency treatment in the treatment of tumors, and the effect of hemostasis is certain [1]. The therapeutic effects were more satisfactory and are reported as follows. Data and methods I. Clinical data There were 12 patients in this group, 10 males and 2 females, with 13 renal tumors, 4 on the left side, 7 on the right side, and 1 on both sides. The age range was 34-83 years, with a median of 64.6 years. 13 cases were confirmed as renal cell carcinoma by routine intraoperative puncture pathology. Among them, 10 cases were clear cell carcinoma and 3 cases were papillary renal cell carcinoma. The maximum tumor diameter ranged from 2.1 to 8.5 cm, including T1N0M0 in 11 cases and T2N0M0 in 2. Hemoglobin, erythrocyte sedimentation rate, blood creatinine, ECT-glomerular filtration rate (ECT-GFR), CT and ultrasonography were routinely checked before and after surgery. None of the cases were treated with chemotherapy or renal artery embolization before surgery. The case selection criteria followed the discussion on the indications for radiofrequency ablation of renal cancer. The procedure was prepared according to the preoperative routine of laparoscopic surgery and general anesthesia. During the operation, laparoscopic exploration was performed to clarify the location of the tumor and determine the puncture site [1], and the tumor was fully exposed to keep it away from the peritoneum and other surrounding organs. A 22 G puncture biopsy needle was routinely used to perform 2 puncture biopsies of the tumor under laparoscopic surveillance and sent for pathological examination. The renal artery blood flow was blocked and the electrode was punctured into the tumor tissue under laparoscopic surveillance, CO2 was expelled if necessary, and the depth of puncture was determined with the aid of extracorporeal ultrasound to ensure that the needle was in the center of the tumor. The cold circulation pump and RF generator were turned on sequentially. The cold circulation pump continuously pumps ice water into the built-in tube of the electrode to keep the needle tip temperature at 16℃～20 ℃. The output power is 150 watts for single needle and 190 watts for cluster needle, and the treatment lasts for 12 minutes. The tissue temperature rises above 60 ℃ at the end of treatment, which ensures the killing of tumor cells. The coagulation foci can be up to 4 cm for single-needle electrodes and about 7 cm for cluster-needle electrodes. Multiple ablations can be performed with a single needle if necessary. The output power is adjusted to maintain the needle tip temperature at 90 °C to 100 °C for 10 seconds, thus causing the needle tract to carbonize and stop bleeding. For poor coagulation and long needle tracts, carbonization can be done in stages, which also prevents needle tract metastasis. Postoperative routine anti-inflammatory and rehydration support treatment. The hemoglobin, creatinine and ECT-glomerular filtration rate were compared before and after surgery. CT and ultrasonography were used to evaluate the treatment effect. At 6 weeks postoperatively, the tumor was completely ablated (Complete ablation (CA)) by enhanced CT scan + 3D reconstruction with complete hypodensity and no enhancement in the tumor area. After complete ablation of the tumor was determined, local recurrence was considered if the original lesion was found to be resupplied with blood, increased in size, or new nodules appeared immediately adjacent to the original lesion during the follow-up period, which was confirmed by enhancement CT. Distant recurrence is defined as the occurrence of new tumor nodules within the kidney that are not directly connected to the original lesion or metastases to extra-renal tissues and organs [2]. Enhanced shadowing around the ablation area has been reported not to suggest tumor recurrence, but mostly benign granulomatous reaction [3]. IV. statistical methods Paired t-test was performed using SPSS Release 11.5.0 statistical software.