Kevin Koo, MD, MPH, on a digital stone measurement tool for ureteroscopy

A recent study published in Urology suggests that the ability to take stone measurements intraoperatively may have significant implications for surgical decision-making and procedural efficiency.¹

Senior author Kevin Koo, MD, MPH, recently sat down with Urology Times® to outline the background and key findings from the study. Koo is a urologist at Mayo Clinic in Rochester, Minnesota.

Overall, Koo noted, “The findings support our hypothesis that empowering kidney stone surgeons with information about the size of the stones that they're treating and the size of the fragments that are produced gives them actionable information about how they can optimize what they're doing in surgery and then optimize patient outcomes after surgery.”

In total, the study prospectively enrolled 106 patients who were undergoing flexible ureteroscopy and holmium laser lithotripsy for renal stones. During the study, surgeons could request intraoperative measurements of fragments in real time. Surveys were conducted after each case to assess the reasons for taking measurements and the impact of the data on intraoperative decisions.

Data showed that surgeons took an average of 2.4 measurement per case. According to the authors, “Surgeons' most frequent reason for taking intraoperative measurements was to determine whether postlithotripsy fragments were extractable (52%), but they also requested measurements to assess stone size (30%) and extractability (34%) before lithotripsy.”

Surgeons changed their intraoperative plans in 28% of cases based on stone measurements. In these cases, surgeons instead opted to continue lithotripsy (11%), extract the fragments (14%), or leave the fragments behind for passage (3%).

Notably, 61% of surgeons rated the ability to take intraoperative measurements as “very helpful,” and 38% rated it as “somewhat helpful.” The authors also noted that, “The time burden of taking measurements affected procedural efficiency in 3% of cases.”

REFERENCE

1. Krueger ABC, Smith DM, Parzych AT, et al. Impact of intraoperative digital stone measurement on surgeon decision making in ureteroscopy. Urology. 2025:S0090-4295(25)00643-0. doi:10.1016/j.urology.2025.06.064