Clinical outcomes of 20-W versus 100-W holmium:YAG laser systems in retrograde intrarenal surgery: Implications for resource-constrained practice

High-power holmium:yttrium-aluminium-garnet (Ho:YAG) systems offer a wider operating range for laser lithotripsy, but the additional capability may be difficult to justify in resource-constrained practice. We compared outcomes after retrograde intrarenal surgery (RIRS) performed with 20-W and 100-W Ho:YAG systems. This retrospective cohort included 125 consecutive adults treated between March 2023 and June 2025 with a Lumenis 100-W (n = 87) or 20-W (n = 38) Ho:YAG system. Operative time was the primary outcome, and stone clearance was assessed by computed tomography of the abdomen at 4 weeks. Stones were larger in the 100-W group (1.62 ± 0.55 vs 1.16 ± 0.31 cm; P < 0.001). Mean operative time was 47.50 ± 20.51 versus 40.21 ± 20.24 minutes (P = 0.069). Complete clearance was achieved in 59/87 (67.8%) and 30/38 (78.9%) patients, respectively (P = 0.283). The need for ancillary procedures, Clavien-Dindo grade I-II complications, and total laser energy were also similar; no grade III or higher complication occurred. In this cohort, the 100-W platform did not show a clear clinical advantage over the 20-W platform. Because treatment allocation was non-random and larger stones were preferentially treated with the 100-W system, these data do not establish equivalence. They do, however, suggest that a 20-W Ho:YAG system remains a reasonable option for appropriately selected RIRS cases in centres where high-power equipment is difficult to justify.