# Optimal duration between drainage for obstructing renal or ureteral stones associated with infection and ureteroscopic lithotripsy: a randomized controlled trial

## TL;DR

This study found that waiting 14-21 days after kidney drainage for an infection before lithotripsy reduces post-surgery infections compared to waiting only 7 days.

## Contribution

The study identifies an optimal 14-21 day interval for ureteroscopic lithotripsy after kidney drainage to minimize infectious complications.

## Key findings

- Early ureteroscopy (7 days) had higher postoperative infectious complications (56.8%) compared to delayed (14-21 days, 30.8%).
- Delayed group had more unplanned hospital visits during the waiting period (36.5% vs. 11.4%).
- Hospital stays and stone-free rates were similar between the two groups.

## Abstract

This study was done to determine the optimal interval between drainage of obstructed infected kidney and ureteroscopic lithotripsy.

This randomized controlled trial was conducted between May 2023 and July 2024. Inclusion criteria were adult patients with obstructed infected kidneys by renal or ureteric stones. After drainage of the kidney, they were randomized into early and delayed groups. In the early group, ureteroscopy was done after 7 days while in the delayed group, ureteroscopy was done after 14–21 days of drainage. The primary outcome was the difference in incidence of postoperative infectious complications. Infectious complications were defined as having one of the criteria of systemic inflammatory response syndrome (SIRS) with infected urine culture. Secondary outcomes were unplanned visits during the waiting period, hospital stay and stone-free rates (SFR).

The study included 96 patients (44 in early group and 52 in delayed group). Post-ureteroscopy infectious complications were significantly more in the early group (56.8% versus 30.8%, P = 0.01). The rate of unplanned hospital visits during waiting period was higher in the delayed group (36.5% versus 11.4% in the early group, P = 0.005). Hospital stays after ureteroscopy and SFR were comparable between both groups (P = 0.227 and P = 0.464).

The preferred timing for ureteroscopy after drainage of obstructed infected kidneys with urolithiasis may be between 14 to 21 days because early intervention was associated with a higher incidence of infectious complications.

The protocol for the trial was registered in ClinicalTrials.gov (NCT06101563) on October 20, 2023.