A prospective comparative study of mini-PCNL using Trilogy™ or thulium fibre laser with suction

There has been recent introduction of novel lithotripters and high-power lasers for stone disintegration. With miniaturization of PCNL, there is need of effective disintegration and faster stone-clearance. This study aimed to evaluate efficiency of Trilogy™ and Thulium fibre laser (TFL) in mini-percutaneous nephrolithotomy (mini-PCNL).

This is prospective study comparing efficiency and outcomes of Trilogy™ and TFL in mini-PCNL between January 2019 and February 2020. Primary objective was to compare stone fragmentation rates, with secondary objectives beings stone-free rates and complications.

There were 60 mini-PCNL with suction using either Trilogy™ or TFL energy source. Mean stone size and density were 27.60 ± 10.17 mm, 22.04 ± 9.69 mm (p = 0.05) and 1172.9 ± 313.5HU, 1308.9 ± 333.9HU (p = 0.10) for Trilogy™ and TFL, respectively. Using 3D doctor imaging software from CT images, mean stone volumes were 3718.9 ± 3038.7mm³ for Trilogy™ and 3425.9 ± 3096.1mm³ for TFL(p = 0.77). Using probe-activation time or lasing time, stone-fragmentation rate was 5.98 ± 4.25mm³/sec for Trilogy™ and 3.95 ± 1.00mm³/sec for TFL(p = 0.015). Treatment time (puncture to complete clearance) was 32.48 ± 15.39 min for Trilogy™ and 28.63 ± 18.56 min for TFL(p = 0.38). Haemoglobin drop was 1.19 ± 0.76gm/dl for Trilogy™ and 0.99 ± 0.74gm/dl for TFL (p = 0.30). Trilogy™ arm had 96.6% complete clearance and TFL had 76.6% in TFL at 48 h. One patient in Trilogy™ arm required auxiliary RIRS for residual stone. Both arms had complete stone clearance at 1 month follow-up. Trilogy™ arm had 3 Clavien-Dindo grade-II complications while TFL had 2 Clavien-Dindo grade-II complications (UTI requiring antibiotics). There was no blood transfusion in either of arm.

Trilogy™ had significantly better stone fragmentation rate than TFL in managing renal stones. However, stone-free rates and complications were comparable for Trilogy™ and TFL.