The Role of Flexible Laser Ureterorenoscopy in the Management of Lithiaises of the Lower Calyceal Group ≥ 2cm

Introduction: Lower calyceal stones account for 35% of urinary stones. However, little is known about their clinical and therapeutic epidemiology in Gabon. Objective: To evaluate the feasibility and results of flexible laser ureterorenoscopy in the management of stones larger than 2 cm located in the lower calyx. Patients and methods: We conducted a retrospective observational study over a period from January 2021 to September 2023. This was a single-centre study carried out at the Omar Bongo Ondimba Military Teaching Hospital in Libreville. We included 89 patients with lower calyceal stones treated with flexible laser ureterorenoscopy. Results: All patients had urolithiasis diagnosed on the basis of clinical findings and confirmed in 100% of cases by non-contrast thin-section CT scanning of the urinary tract. The mean age of patients was 35 ± 7 years, with extremes of 16 and 62 years, and a clear female predominance (54%). All stones were located in the lower calyx, with a predominance of calcium oxalate monohydrate stones (20%). Ninety-one per cent (91%) of patients had stones between 2.3 and 3 cm in size, and 9% (9 patients) had stones larger than 3 cm. Most stones were unilateral, with only 11 patients having bilateral stones. All patients were treated with URSS-YAG laser in its various modes. In total, we performed 97 procedures with a clearance rate of 91% and 100% after one and two sessions, respectively. The average length of hospitalisation was 1.5 days. Post-operative complications were minor in 100% of cases. Conclusion: Based on our results, laser URS appears to be the first-line treatment for stones greater than or equal to 2 cm located in the lower calyceal group in our context.