Skip to Content
Authors Bell JR, Penniston KL, Nakada SY
Author Profile(s)
Journal J. Endourol.
Publish Date 2017 Jul 20
PubMed ID 28728505

INTRODUCTION AND OBJECTIVE There is limited data regarding optimal laser and energy settings during stone fragmentation. We assessed effects on fragmentation using a variety of energy and frequency settings with two laser systems. METHODS Artificial stones were created using BegoStone (Streeper et al 2016). A clear PVC tube with an inner diameter of 13mm was closed at one end with a removable plug to create the in vitro ureteral and calyceal environments. The Lumenis Pulse 120H and the Cook Rhapsody H-30 holmium lasers were studied in the calyceal and ureteral models. A single urologist fragmented each stone to <2mm. The calyceal studies assessed the time to fragmentation (n=56); whereas the ureteral studies measured the retropulsion distance of each stone phantom after five minutes of laser treatment time using different pulse widths settings (n=15). RESULTS Complete treatment of the stone in the calyceal model with the 120H required 10.9min at ≥1J vs 26.9min at <1J (P<0.001). The H-39 showed treatment times of 11.2min at ≥1J vs 22.8min at <1J (P<0.001). There was no significant difference in treatment time when comparing the two lasers using settings of 0.8Jx8Hz and 1.5Jx10Hz in the calyceal model (25.5 vs 24.8min, P=0.861; and 13.2 vs 9.5min, P=0.061; respectively). Ureteral studies with the 120H showed retropulsion distances of 13.9cm using long pulse, 25.2cm using medium pulse, and 56.6cm using short pulse. Retropulsion distances using the H-30 laser were 7cm using long pulse and 14.5cm using short pulse which differed from the 120H (P<0.001). CONCLUSIONS Fragmenting stones to <2mm was faster with both lasers when energy settings of ≥1J were used. Treatment times using the 120H and the H-30 lasers were equivalent. Retropulsion distances were less with both lasers when longer pulse widths were used. The H-30 resulted in less stone retropulsion compared to the 120H. Copyright © 2017 The Board of Regents of the University of Wisconsin System