A novel robotic-assistant flexible ureteroscopy system: initial results from the in vitro study and the in vivo experience / 中华泌尿外科杂志

ABSTRACT

Objective:Objectives The aim of the study is to evaluate the mechanical performance, safety and efficacy of the novel robotic-assistant flexible ureteroscopy system (Ra-fURS) under in vitro and in vivo environments.Methods:Combing with commercial flexible ureteroscopes, the novel Ra-fURS was used for the in vitro test and animal model operation in October 2020. The study included three sections. ①Basic mechanical performance assessment including endoscope motion control (dual deflection, axial rotation and forward/backward distance), reaction time and fiber regulation. ②Simulated surgery in ex-vivo 3D-printing renal collecting system model including completion rate and time of calyxes exploration, directional movement and laser fragmentation [gypsum models (0.5×0.5×0.5 cm) were used to stimulate kidney stones]. ③Intrarenal surgeries in animal models (two 5-month female Yorkshire white pigs). In total, 32 surgeries was performed (8 surgeons × 2 pigs × 2 kidneys/pig). In vivo assessments were carried out including ①consuming time for Ra-fURS installation and offloading; ②completion rate and time of calyxes exploration; ③comfort score (ranging from 0-10) as compared to the manual f-URS, which was corresponding to each Ra-fURS surgery. In simulated surgery and animal surgery sections, 8 surgeons were enrolled in the study (group A 4 without flexible ureteroscopy experience; group B 4 highly experienced), and results were compared between two groups.Results:Under the Ra-fURS control, the flexible ureteroscope movement in three degrees of freedom (forward / backward + 11 to -11 cm, axial rotation + 225°to -225°; active duel-flection + 270°to -270°, as well as the laser fiber regulation + 2.5 to -2.5 cm). In simulated surgery tests, both groups achieved 100% completion rate of calyxes exploration, and there were no statistical differences in the time of the calyxes exploration between group A and group B (116.0±8.0)s vs.(110.3±15.4)s( P>0.05). Time-consumption for laser fragmentation of group B was shorter than that of group A (525.8±58.5)s vs. (780.5±141.2)s( P<0.01). In animal surgery, the installation time of Ra-fURS gradually shortened within the first 7 cases was(234.0±43.0)s, and became comparable in the later 8-32 cases was(149.3±8.0)s. The average uninstall time was (43.9 ±5.9)s and was relatively stable. There were 51 renal calyxes in two pigs. It was higher for the completion rate of calyxes exploration in group B than in group A [(95.5±9.1)% vs. (59.1±9.1)%, P<0.05], and the exploration time was also statistically variant between the two groups group A and group B[(274.8±34.6)s vs.(127.3±18.2)s, P<0.05]. For all the operators, the comfort scores were favorable to the Ra-fURS as compared to the manual f-URS (8.9±0.3 vs. 5.9±1.1, P<0.05). Conclusions:This preliminary study demonstrated that the novel Ra-fURS was capable of controlling flexible ureteroscope to perform retrograde intrarenal surgery and fragmenting stones with laser. Besides, other features, including easy installation, stable performance and comfortable manipulating environment, made it easy to use in clinical application.