Dutta R, Mithal P, Klein I, Patel M, Gutierrez-Aceves J. Outcomes and costs following mini-percutaneous nephrolithotomy or flexible ureteroscopic lithotripsy for 1- to 2-cm renal stones: data from a prospective, randomized clinical trial. J Urol. 2023;209(6):1151-1158.

Study Need and Importance

Both mini-percutaneous nephrolithotomy (mPCNL) and ureteroscopic lithotripsy (URS) are options for treating renal stones sized 1-2 cm. Limited direct comparisons of outcomes and procedural costs between the 2 surgical techniques exist.

What We Found

In a randomized controlled clinical trial, mPCNL with a urologist obtaining percutaneous access significantly outperformed URS in rendering patients stone-free using both 0-mm and 2-mm residual stone burden cutoffs. There were no differences in surgical time, 30-day complications, the necessity for a secondary stone procedure, or pre- to postoperative serum creatinine change. Fluoroscopy time and length of stay were both higher in the mPCNL cohort, as the authors’ practice at the study time was to keep all mPCNL patients in the hospital for observation for 1 night. Although costs were higher in the mPCNL cohort, this was offset by a higher revenue, resulting in no significant change in total hospital operating margin.

Limitations

Although postoperative imaging was standardized to low-dose stone protocol computed tomography, the timing of the scan varied between groups (postoperative day 1 for mPCNL patients staying overnight and postoperative day 1-30 for URS patients). Finally, all surgery was performed by a single endourologist with expertise in both surgical techniques, limiting the generalizability of our findings given the variations in comfort and training in urologists performing stone surgery.

Interpretation for Patient Care

mPCNL is more likely to render patients stone free than flexible ureteroscopy. There are no differences, on average, in short-term complications, operating times, and operating margins between the 2 surgeries.