Evaluation of a urinary filtration device for kidney stone retrieval: Pi-Box®

There is an unmet need to offer a proper urinary straining device for patients in whom spontaneous expulsion of stones is expected. The objective of this study was to assess the efficacity, duration and ease of use of a new filtration device: the Pi-Box®.

This was a single-institution, non-randomized open-label study. Consecutive male patients with at least one stone that was susceptible of spontaneous passage, or after shockwave lithotripsy were included. The first 30 consecutive patients (Group 1) used the usual recommended techniques, and the 30 following consecutive patients (Group 2) were given the Pi-Box®. The patients completed a questionnaire when seen at 1-month follow-up.

Sixty men were included between January 2023 and May 2023. Thirteen (43%) patients retrieved a stone in each group (P=1). Filtration was performed for a median of 5 days in Group 1 and 10 days in Group 2 (P=0.03). Fourteen (46%) patients were satisfied or very satisfied with their filtration technique without the device versus 18 (60%) with the Pi-Box® (P=0.3). Eighteen (60%) and 21 patients (70%) would recommend their straining technique to a relative in groups 1 and 2, respectively (P=0.42).

The number of straining days was twice longer with the Pi-Box® device and is in favor of a better observance. The device did not increase the number of stones retrieved by urine filtration, which was high in this pilot study and may have been due to a participation bias.

2B.