Re: Mahajan AD, Mahajan SA. Thulium fiber laser versus holmium:yttrium aluminum garnet laser for stone lithotripsy during mini-percutaneous nephrolithotomy: A prospective randomized trial. Indian J Urol 2022;38:42-7

We read the article, “Thulium fiber laser versus holmium: yttrium aluminum garnet laser for stone lithotripsy during mini-percutaneous nephrolithotomy: A prospective randomized trial,[1] ” with interest. The authors have elegantly demonstrated that the thulium fiber laser (TFL) showed a shorter stone disintegration time (11 min 19 s vs. 20 min 45 s, P < 0.001) and operating time (55 vs. 68 min, P = 0.001) with similar stone clearance rates (94.9 TFL vs. 90.9% holmium:yttrium aluminum garnet [Ho-YAG]). Most complications were minor and self-limiting while hematuria was more common in the thulium laser fiber arm (13 vs. 2, P = 0.002). The following details, if added, will enhance the quality of the article and make it a valuable contribution to the level 1 evidence in this area, which is lacking. These are in keeping with the CONSORT statement:[2]

1. Time period in which the study was carried out

2. Clinical Trials Registry – India number

3. Whether anomalous stone-bearing kidneys were excluded

4. Exclusions because the patient did not consent or was to loss to follow-up

5. Primary outcome

6. Sample size calculation and assumption made based on published literature

7. Details of when and who performed the randomization and allocation concealment

8. Exclusions during the operation (for example, if conventional percutaneous nephrolithotomy (PCNL) was required instead of mini-PCNL after randomization)

9. If the difference in stone clearance rates between the TFL group (94.9%) and the Ho-YAG group (90.9%) was statistically significant.

The authors have mentioned that the mean hemoglobin drop was 56 g/dL in the holmium arm and 55 g/dL in the thulium arm (the mean hemoglobin in the two groups was 13.3 g/dL and 13.2 g/dL, respectively). These values are high and may require to be corrected.

The authors are to be congratulated for reporting the first randomized study comparing TFL with Ho-YAG in mini-PCNL and for the demonstration of the superior stone fragmentation by TFL which merits further study.