Amir Patel, MD, on ureteral strictures following holmium vs TFL laser lithotripsy

While the rate of ureteral strictures following ureteroscopic laser lithotripsy is low, the incidence was nearly doubled when using a thulium fiber laser (TFL) vs a holmium laser, according to data presented at the 2025 American Urological Association (AUA) Annual Meeting in Las Vegas, Nevada.

In an interview with Urology Times®, lead author Amir S. Patel, MD, offered an in-depth look into these findings and their implications. Patel is an endourology fellow at Northwestern University in Chicago, Illinois.

“TFL is a laser that's a little bit newer on the market compared to the holmium. It has some promising data with regards to surgical outcomes, but we did also note that many studies have noted increased working temperatures with the TFL use, but there has not been any strong studies looking at whether this had an impact on clinical outcomes,” Patel explained.

To that end, the investigators conducted a retrospective database analysis of 6726 patients who underwent ureteroscopic laser lithotripsy. Of those, 6178 had the procedure done with the holmium laser, and 548 had the procedure done with the TFL.

Data showed that the risk of stricture formation was 4.6% in the TFL cohort vs 2.4% in the holmium laser cohort. The adjusted relative risk of stricture formation within 120 days was 1.89 (95% CI, 1.22 to 2.8), per multivariate analysis.

Patel also touched on the implications of these findings for clinical practice.

“The implications of this are pretty significant. I think we do need to be aware of the fact that, whether it be due to the increased temperature or due to more aggressive laser settings used initially, with the advent of the TFL, we did find statistically significant higher rate of strictures with TFL compared to the holmium,” Patel noted.

He also added, “With regards to what can be done, there have been studies that show that ureteral access sheath use and pressurized irrigation are able to reduce the working temperatures in the kidney during laser lithotripsy.”

REFERENCE

1. Patel A, Xu P, Roane A, Gibbs C, Mechlovich D, Stock L, Krambeck A. Ureteral stricture rates after holmium vs TFL ureteroscopic laser lithotripsy: A database analysis. J Urol. 2025; 213(5S):e38. doi:10.1097/01.JU.0001109712.09934.41.08