Category: Clinical Stones: Outcomes

MP8-17 - Natural history of CT-detected residual fragments after aggressive ureteroscopy

Fri, Sep 21
10:00 AM - 12:00 PM

Introduction & Objective : Despite aggressive attempts to remove all fragments after ureteroscopy (URS) for renal and ureteral calculi, stone-free rates by computed tomography (CT) imaging remain disappointingly low.  We prospectively followed patients who underwent ureteroscopy and fragment retrieval to determine the long-term outcome of those left with residual fragments (RF). 


Methods : We prospectively followed 167 patients (209 renal units) undergoing URS for renal and ureteral calculi between December 2015 to February 2017. All patients underwent pre- and 6-8 week post-operative CT.  We analyzed the medical records and imaging studies of patients who were left with RFs of any size who had at least 12 months of follow-up, and we contacted these patients by phone to determine if they had experienced any symptomatic stone events attributable to their RFs.  A stone event was defined as stone passage, need for surgical intervention, symptoms requiring emergency department (ED) visit, or stone growth. Fisher’s exact test was used for categorical variables and multivariable logistic regression (MVA) was used to determine predictors of surgical intervention. Statistical significance was set at p≤0.05.


Results : Among 81 patients (94 renal units) with RF, 50 (61 renal units) (65%) had ≥12 month follow-up (mean follow-up 18.0 ± 4.8 months). The largest mean residual fragment per patient was 3.6 ± 2.0 mm. Overall, stone events occurred in 22 (36.1%) renal units. Stone passage was noted in 6 (9.8%), ED visit without surgical intervention was required in 2 (3.3%), stone growth occurred in 5 (8.2%), and surgical intervention was required in 9 (15%) renal units. Time interval to surgical intervention occurred at a mean of 6.9 ± 4.2 months.  RFs larger than 4 mm were not associated with increased need for surgical intervention (5/14, 35.7%, p=0.45). By MVA, we found no significant independent predictors of need for surgical intervention.


Conclusions : More than a third of patients left with RFs of any size after URS experience a stone-related event. As such, the high rate of RFs after ureteroscopy is consequential, and any measures that reduce RFs, such as better patient selection, are desirable.  

Brett Johnson

Endourology Fellow
UT Southwestern
Dallas, Texas

Brett Johnson, is the current second-year Endourology fellow at University of Texas Southwestern with Drs. Jeffrey Cadeddu and Margret Pearle. He completed residecny in Urology at the University of Wisconson.

Igor Sorokin

Dallas, Texas

Noah Canvasser

Assistant Professor, Dept of Urologic Surgery
UC Davis Medical Center
Sacramento, California

Dr. Canvasser is currently Assistant Professor in the Department of Urologic Surgery at UC Davis in Sacramento, CA. After finishing medical training at UC Irvine, he completed urology residency at the University of Michigan. He subsequently was a fellow in minimally invasive surgery and endourology at the University of Texas Southwestern Medical Center from 2015-2017.

His clinical practice and research interests are focused on the medical and surgical management of complex kidney stone disease, minimally invasive urologic oncology, and minimally invasive urinary reconstruction.

Aaron Lay

Asst Professor
Department of Urology, Emory University School of Medicine
Atlanta, Georgia

Dr. Lay received his medical degree from Washington University School of Medicine in St. Louis in 2009. He completed his general surgery internship and urology residency at Brigham and Women's Hospital, after which he did an endourology and minimally invasive surgery fellowship at the University of Texas Southwestern Medical Center from 2014-2016. Dr. Lay directs the Endourology and Kidney Stone Program at Grady Memorial Hospital.

Jodi Antonelli

Assistant professor urology
UT Southwestern
Dallas, Texas

Jodi Antonelli, M.D. is an Assistant Professor in the Department of Urology at UT Southwestern Medical Center. She specializes in the medical and surgical management of kidney stone disease.
Dr. Antonelli earned her medical degree from Jefferson Medical College of Thomas Jefferson University. She completed a general surgery internship and a urology residency at Duke University Medical Center. She completed a fellowship in endourology and stone disease in the Department of Urology at UT Southwestern.
Her research interests include evaluation of dietary and medical therapies for kidney stone prevention, assessment of outcomes for minimally invasive surgical treatments, and development and assessment of surgical innovation. She was the recipient of the 2014 Elisabeth Pickett Research Award for the Society of Women in Urology.
Dr. Antonelli is a member of the American Urological Association, the Endourological Society, and ROCK Society.

Margaret S. Pearle

Dallas, Texas