BACKGROUND: Telesurgery has the potential to overcome spatial limitations for surgeons, which depends on surgical robot and the quality of network communication. However, the influence of network latency and bandwidth on telesurgery is not well understood. METHODS: A telesurgery system capable of dynamically adjusting image compression ratios in response to bandwidth changes was established between Beijing and Sanya (Hainan province), covering a distance of 3000 km. In total, 108 animal operations, including 12 surgical procedures, were performed. Total latency ranging from 170 ms to 320 ms and bandwidth from 15-20 Mbps to less than 1 Mbps were explored using designed surgical tasks and hemostasis models for renal vein and internal iliac artery rupture bleeding. Network latency, jitter, frame loss, and bit rate code were systemically measured during these operations. National Aeronautics and Space Administration Task Load Index (NASA-TLX) and a self-designed scale measured the workload and subjective perception of surgeons. RESULTS: All 108 animal telesurgeries, conducted from January 2023 to June 2023, were performed effectively over a total duration of 3866 min. The operations were completed with latency up to 320 ms and bandwidths as low as 1-5 Mbps. Hemostasis for vein and artery rupture bleeding models was effectively achieved under these low bandwidth conditions. The NASA-TLX results indicated that latency significantly impacted surgical performance more than bandwidth and image clarity reductions. CONCLUSIONS This telesurgery system demonstrated safety and reliability. A total of 320 ms latency is acceptable for telesurgery operations. Reducing image clarity can effectively mitigate the potential latency increase caused by decreased bandwidth, offering a new method to reduce the impact of latency on telesurgery.
Animals ; Robotic Surgical Procedures/methods* ; Laparoscopy/methods*

【Objective】 To investigate the clinical features and prognostic factors of elderly patients with localized renal cell carcinoma after operation. 【Methods】 Clinical data of all elderly patients (60-100 years old) with localized renal cell carcinoma who underwent primary tumor resection during 2004 and 2017 in United States National Cancer Institute (SEER) database were collected.The clinical features, surgical methods and prognosis were analyzed.According to the surgical methods, the patients were divided into partial nephrectomy (PN) group and radical nephrectomy (RN) group.The effects of the two surgical methods on the prognosis were compared. 【Results】 A total of 20 348 patients were included.The median survival time was 164 months, and the 3-, 5- and 10-year cumulative overall survival rates were 91.1%, 84.2% and 64.4%, respectively.Multivariate Cox analysis showed that age, sex, race, histological grade, T stage and surgical method were independent prognostic factors for overall survival (P<0.05).Subgroup survival analysis showed that the prognosis of PN was superior to that of RN in all age groups, gender, race, histological grade and T1 stage renal cell carcinoma (P<0.05).For T2 stage renal cell carcinoma, there was no significant difference in the prognosis between patients who received PN or RN (P>0.05). 【Conclusion】 Old age, male, black, non-chromophobe cell carcinoma, low degree of differentiation, high T stage of tumor and RN are independent risk factors for the prognosis of elderly patients with localized renal cell carcinoma.PN is the main treatment method and has remarkable therapeutic effects.