In URS, as in every other surgical procedure, patient safety is the main goal for the surgeon. Despite the many improvements over the years (e.g., invention of ureteral access sheaths, dilatators, safety wires, and especially laser lithotripsy), there is still a need to improve endourological safety, as ureteral injury (of any severity) still occurs in up to 30% of URS cases [
11]. Stone diameters greater than 5 mm, a patient history of URS, a dilated proximal ureter, stone location above the ischial spines, and the involvement of a junior urologist are all factors that are known to be associated with a significantly higher incidence of intraoperative complications [
10]. The results of our previous study were in line with those of Patel et al. [
6] and confirmed that endourologists are able to assess residual stone fragment size accurately enough to make intraoperative decisions about direct extraction or further laser lithotripsy. Conversely, we also showed that it was feasible to measure the stone with the described basket handle scale [
8], which could be especially suitable for junior endourologists; however, improvements regarding the accuracy of this new method were required and a possible solution is provided in the current study. It has been already shown that the visual stone size estimation is biased by multiple factors, such as the color of the stone and the experience of the surgeon [
8]. Interestingly, a slight tendency to underestimate the size of large stones (> 6 mm) was observed [
8]; therefore, the measurement of these stone sizes could be enhanced with the proposed basket prototype.
It is already known that intraoperative visual stone assessment and measurements using regular preoperative diagnostic tools (i.e., CT and ultrasound) are biased [
12‐
14]. Other experimental methods such as ultrasound strain sonography have not yet gained clinical application [
15]. In our opinion, the modified measuring basket prototype reported here could attempt to level these discrepancies and objectify stone size measurements in the future.
Ludwig et al. recently proposed another approach to improve the intraoperative stone measurement accuracy that was based on additional measuring software calibrated in accordance with the distance of the basket tip in the visual field of the ureteroscope [
16]. Future comparison between the “hardware” basket concept and the proposed URS software would be surely interesting to assess their influences on intraoperative outcomes and patients’ safety.