This was a retrospective observational study to determine the efficacy and safety of suctioning flexible ureteroscopy with intelligent pressure-control (SFUI) in the management of upper urinary tract calculi in a sizable population. The hospital enrolled 278 patients who had SFUI for upper urothelial tract stones between July 2020 and August 2021. Among the results measured were the percentage of patients who were stone-free rate (SFR) after a single SFUI treatment session and after 1 month, as well as the incidence of complications as measured by the Clavien-Dindo scale.

There were a total of 310 kidneys that passed through SFUI. A typical surgical procedure took 75 minutes (ranged 60–110 minutes). The SFRs after 1 session was 80.65%, and after a month, they were 82.26%. With stones less than 40 mm in size and Guy’s stone score of grade I had an SFR greater than or equal to 87% after a single treatment session. Stone history (adjusted odds ratio [aOR]: 2.39, 95% CI: 1.21-4.73), stone size of 40-49 mm (aOR: 4.37, 95% CI: 1.16-16.45), Guy’s stone score of more than equal to Grade II (aOR: 3.54, 95% CI: 1.18-10.59; Grade III, aOR: 10.95, 95% CI: 2.65-45.25) were all risk factors for single session failure. Researchers found that 3.26 percent of patients experienced a Clavien-Dindo grade II-III complication. Guy’s stone score III is predictive with complications (aOR = 22.36, 95% CI = 1.81-276.36).

The treatment of calculi in the urethra and urethral neck with SFUI is safe and effective. After SFUI treatment, patients with stones less than 40 mm or with Guy’s stone score of Grade I have an excellent probability of being stone-free.