for people ages 18 years and up (full criteria)
at San Diego, California and other locations
study started
completion around



The rationale for this study is to determine if there is a difference in complications among patients undergoing ureteroscopy for renal stones who receive a stent compared to not receiving a stent postoperatively.


Kidney stones affect 9% individuals within the United States, and the prevalence is increasing. Over the last few decades, ureteroscopy has become the most commonly performed stone procedure. However the complication rate after ureteroscopy is not insignificant. Reducing morbidity after ureteroscopy would improve patient outcomes and reduce health care utilization.

A major contributor to patient morbidity after ureteroscopy is the ureteral stent, which is placed at the time of surgery and left in place 1-2 weeks after surgery. The rationale for utilizing stents is to prevent urinary obstruction from edema or stone fragments. On the other hand, stents cause hematuria, pain, and lower urinary tract symptoms. Additionally, stent-related symptoms are often misdiagnosed as urinary tract infections leading to unnecessary antibiotic use.

The clinical utility of ureteral stents after ureteroscopy has not been well studied, specifically a stone located in the kidney. Prior studies on stent-less ureteroscopic procedures have focused on treatment of ureteral stones and not stones located in the kidney, have had restrictive inclusion and exclusion criteria, are primarily from single center institutions, and most being performed ~15 years ago. Surgical techniques and device innovations have changed the procedure since that time. To date, there have been only 2 studies that included stone located in the kidney showing no difference in unplanned hospital revisits, however both combined analyses with ureteral stones and selection bias was an issue for both studies. In addition, there is a lack of studies assessing opiate use, impact of quality of life with stent placement, and loss of work related to stent placement


Kidney Calculi, Nephrolithiasis, Calculi, Ureteroscopy


You can join if…

Open to people ages 18 years and up

- nonobstructing renal stone 1.5cm total stone diameter (if multiple stones, then sum of maximum diameters) or less undergoing ureteroscopy

You CAN'T join if...

  • age < 18 years
  • pregnancy status
  • ureteral stone
  • preoperative hydronephrosis
  • indwelling nephrostomy tube
  • planning bilateral ureteroscopy or subsequent staged ureteroscopy
  • solitary kidney or eGFR <60 mL/min (CKD stage 3 or greater)
  • variant anatomy including horseshoe kidney, pelvic kidney, prior urinary tract reconstruction


  • University of California San Diego accepting new patients
    San Diego California 92121 United States
  • University of California Los Angeles accepting new patients
    Los Angeles California 90095 United States


accepting new patients
Start Date
Completion Date
Vanderbilt University Medical Center
Study Type
Expecting 200 study participants
Last Updated