The Avicenna Roboflex URS-Robot used for retrograde intra-renal stone surgery in clinical routine made the “robolution” come true in Endourology. Safety and feasibility of the system was shown. This study investigates the non-inferiority of the system compared to classical fURS in a head to head design.
To compare fURS with rfURS we prospectively analyzed two groups of each 100 patients undergoing retrograde intra-renal stone surgery. Group 1 was treated with conventional fURS and Group 2 was treated using the robotic system. According to the head to head design two groups showed comparable parameters according demographic and stone parameters: fURS: gender m/f 1/2; BMI 28,1; ASA 2,7; rfURS: gender f/m 1,5/3; BMI 27,5; fURS: stone load/kidney: 2729 mm3 (10; 35000), number of stones/kidney 1,88 (1; 10); rfURS: stone load/kidney: 2957 mm3 (27; 27000), number of stones/kidney: 1,97 (1; 9). 3 surgeons experienced in both techniques performed all cases using the digital scope Storz Flex Xc. The majority of patients were pre-stented (fURS: 94%; rfURS: 98%) and treated with an access sheath (fURS: 84%; rfURS: 100%) using laser lithotripsy (fURS: 96%; rfURS: 96%).
Apart from the higher stone-clearance rate (34,9 mm3/min vs.44,8 mm3/min ) and radiation exposure (274 (23,7; 1598) vs. 206 (19,5; 815) cGy*cm2) favoring rfURS there were no significantly different results in both groups: fURS: OR-time 78min (18; 218), intra-op complications: 2% bleeding; stone free rate (SFR): 93%, post-op complications: 8% fever (7%), hematoma (1%); rfURS: OR-time: 90 min (18;263), docking time 5 min(1; 24), console time: 66 min (5; 200); console time to stone contact :6min (0,5; 25); intra-op complications: 2% bleeding 1%, ureteral perforation 1%, SFR: 94%, post-op complications: 5% sepsis (1%), fever (2%), sub-capsular hematoma(1%), myocardial infarction (1%).
In terms of safety and outcome both surgical techniques showed similar results. There is no superiority of one procedure. The slightly longer OR-time in the rfURS group is due to the docking and preparation process of the robot. In terms of surgical outcome the rfURS System is not inferior to fURS, but offers a faster stone clearance rate and lower radiation exposure, which can be beneficial especially in the treatment of larger and complex stones.