Safety and efficacy of ureteroscopy and laser lithotripsy with a single-use 7.5Fr ureteroscope: a multicenter...

The treatment of kidney stone disease (KSD) has evolved significantly with the introduction of minimally invasive endourological techniques. Advancements in technology, particularly the transition from fibreoptic to digital and single use systems and the development of smaller-diameter instruments, has improved intraoperative view and efficacy in stone treatment. The miniaturization in single-use scopes represent a recent innovation, offering potential benefits, especially in challenging cases. However, there is limited evidence on their safety and clinical outcomes. This study aims to evaluate the efficacy and safety of stone treatment using a single-use 7.5 Fr flexible ureteroscope.

Consecutive patients with urinary stones undergoing flexible ureteroscopy with a 7.5 Fr single-use flexible ureteroscope across five tertiary endourology centers were included. Data on patient demographics, stone characteristics, intra- and postoperative outcomes were prospectively collected and analyzed. Procedures were performed by experienced endourology surgeons following standard protocols.

50 patients with a mean age of 54.5 years (IQR: 25-65.8) and a male to female ratio of 34:16 underwent flexible ureteroscopy (FURS). Mean cumulative stone size was 18.9 mm (SD ±10.9 mm) with a mean stone volume of 2031.2 mm³ (SD ±2869.4 mm³) and mean Hounsfield units of 1087.4 (SD ±384.9). 36 (72%) had multiple stones and a bilateral FURS was performed in 9 cases (18%). 24 patients (48%) had a preoperative stent inserted. A ureteral access sheath was used in 22 (44%) cases and 46 (92%) patients had a postoperative stent inserted. The median operative time was 60min (IQR: 53-90), 32 patients (64%) were stone free after the first procedure (SFR for <2 cm and ≥2 cm stones was 85.2% and 36.2% respectively), perioperative and postoperative complications (Clavien ≤II) were observed in 3 patients (6%).

This multicentric study demonstrates the safety and efficacy of using the 7.5Fr single-use flexible ureteroscope for urinary stone treatment. While the results are promising, larger studies are needed to validate these findings further.