In this article, we first reviewed the reported cases of robot-assisted laparoscopic surgeries, and found that remote robotic surgeries have been successfully applied in procedures across urologic, hepatic, gastrointestinal, gynecologic, and thoracic surgery. Most of these surgeries were conducted using a single console, via the 5G wireless networks, and had a latency time greater than 150ms (Table 1). Although previous studies have indicated that single-console telesurgeries with 5G wireless networks had a satisfactory performance concerning latency time and video quality, it is important to recognize that these early telesurgeries often involved simple surgical procedures, and were better prepared and supported. Telesurgery with multiple consoles and the "5G wireless + wired" networks can accommodate more complicated surgeries and network conditions, meeting the practical application scenarios of future remote robotic surgery.
3.1 The Importance of Multiple Consoles in Complicated Telesurgery
Presently, the vast majority of telesurgeries are based on single-console. Although it meets the basic requirements of robotic telesurgeries, it has obvious disadvantages compared with multi-console system (12). Firstly, the safety of multi-console surgeries surpasses that of single-console operations, significantly reducing the risks associated with console malfunctions (13). Secondly, multi-console system facilitates the multi-disciplinary collaboration on the robotic platform. Due to safety considerations, previous and current telesurgeries have been limited to animal experiments, cadaver surgeries, and simple human surgeries (3, 5, 9). However, with the widespread adoption of surgical robots and the improvement of networks, telesurgery is gradually utilized in procedures requiring complicated dissections and multi-disciplinary collaborations. The multi-console system will enable the experts in different hospitals to operate nearby robotic consoles when they were called to join the surgery. Our surgical team has previously joined the successful "5G wireless + wired network" pyeloplasty in pigs using two consoles, but the limited number of consoles and the short distance between the consoles and the patient cart did not fully simulate the real collaberation scenario (8). In our surgery, three surgeons from Beijing and Liaoyang, conducting their consoles, collaborated smoothly during the telesurgery, and obtained the successful experiences of utilizing multiple consoles in multi-disciplinary robotic telesurgery. This will significantly reduce the time cost for surgical experts and substantially increase the feasibility of complicated multi-disciplinary surgeries.
3.2 The Importance of Multiple Consoles in Surgical Training
Surgical education has always been a challenge of clinical education. Despite of the development of simulation-based teaching or video learning, the face-to-face teaching during surgery is irreplaceable (14, 15). In the conventional laparoscopic surgery era, the instructions provided by senior surgeon to junior surgeon during the surgery was largely verbal, leading to potential misunderstandings due to unclear instructions or incorrect interpretations. Furthermore, when junior surgeon encounters difficulties and needs the help of the senior, they need to exchange their positions and surgical instruments, which affect not only the continuity and safety of the surgery but also the effectiveness of teaching and the willingness of seniors to teach. Multi-console system enables senior surgeon to make annotations on the robot's screen to accurately explain anatomical features and provide straightforward guidance on surgical steps. Multi-console system can also allow the seamless switch of control of the robot between senior and junior surgeons, facilitating the surgical education.
3.3 The Practical Significance of "5G wireless + wired network" in Robotic Telesurgery
The 5G wireless network bears the advantages of "high bandwidth, low latency, and extensive connectivity". In battlefield, where it is difficult to establish wired networks, 5G network enables surgeons to perform telesurgeries from the home front (16). High-quality network is the foundation of satisfactory surgical outcomes. At present, the latency for most telesurgeries based on 5G networks is approximately 200ms, and is longer than telesurgeries based on wired network (12, 17–19). Worldwidely, most of areas have no access to the high-quality 5G signals meeting the requirement of robotic telesurgery, most of robots are placed in certain hospitals. Thus, connecting the patient cart via a wired network can maximize the robot's function. Shubo et al. previously utilized the "5G wireless + wired network" model to perform double-J stent insertion; however, the short distance between the console and patient cart and the simple surgery may not approve the actual effectiveness of this network model (8). In this telesurgery, the patient was 700km away from the console. We connected the robot in Liaoyang city to a wired network, simulating the network condition of a primary hospital with unstable 5G signals. By connecting the surgeon console with 5G in Beijing, we simulated the scenario that a surgeon performed the telesurgery in a uncertain hospital with satisfactory 5G network. Our "5G wireless + wired network" model had the latency of 220ms, reaches the ideal range of latency for telesurgery, and secured the safety of telesurgery. Moreover, when surgeons in high-level hospitals can perform the operations for patients within 700 kilometers, the telesurgery can cover the patients across the central, eastern and some parts of western China. This "5G wireless + wired network" model with this coverage bears more practical significance for the robotic telesurgeries.
3.4 Challenges in Multi-Console Telesurgeries
Firstly, latency is the most crucial parameter for telesurgery. A latency of 0-200ms is most ideal, ≥ 300 ms leads to the deterioration of skill (17, 20). Therefore, the primary challenge of telesurgery is to minimize latency as much as possible. Secondly, given that telesurgery is still under development, potential network and robot malfunction may threaten the patient's safety. The requirement of a skilled surgeon team beside the patient cart limits the promotion of telesurgeries (21). Therefore, the stability of network and robot is also the main challenge. Thirdly, there are still few multi-console robotic telesurgeries, and it is necessary to explore the impact of different numbers of consoles, distances, and network models on the performance of surgery, and to accumulate more experience in telesurgeries.