Category: Clinical Stones: SWL

MP9-13 - Are Stone Surgeons Diversified in Shock Wave Lithotripsy and Ureteroscopy Volumes?

Fri, Sep 21
2:00 PM - 4:00 PM

Introduction & Objective :

Guidelines for surgical management of upper urinary tract calculi recommend either shock wave lithotripsy (SWL) or ureteroscopy (URS) depending on stone size and position.  However, data have shown down-trending use of SWL over time.  We sought to understand whether urologists performing SWL have SWL-dominant practices or diversified practices with both SWL and URS.  We hypothesized that there is an inverse relationship between SWL and URS volumes.

Methods :

Using the 2015 Medicare “Provider Utilization and Payment Data: Physician and Other Supplier Public Use File” (, we determined case volumes of SWL (CPT 50590) and URS (CPT 52356 or 52353) for individual urologists. This dataset excludes providers who perform ten or fewer procedures per year. We categorized case volumes by quintile for each procedure and compared the volumes of SWL and URS. Data were analyzed with Stata 13.0 using summary statistics, two-sided t-tests, and Pearson correlation to compare SWL and URS volume overall and for the highest volume SWL providers.

Results :

We identified 2,676 urologists who performed 8,853 URS and 10,658 SWL procedures on Medicare patients in 2015. Of those, 1,148 (42.9%) performed SWL only, 1,044 (39.0%) performed URS only, and 484 (18.1%) performed both SWL and URS.  Mean cases per provider were 21.7 +/- 12.2 (median 18) for SWL and 18.2 +/- 7.9 (median 16) for URS. There was a significant difference in case volume between the upper quintile of SWL (mean 38.9 +/- 15 cases, 355 providers) and URS (29.5 +/- 9.1, 347 providers) (p<0.001).  For urologists performing both procedures, there was a weakly positive correlation between SWL and URS volume (coeff = 0.268, R-squared = 0.029, p<0.001). However, for SWL providers in the top quintile, the correlation with URS volume was stronger (coeff = 0.619, R-squared = 0.171, p<0.001).

Conclusions :

Most urologists perform either SWL or URS, supporting the hypothesis of dichotomized practice patterns. For those performing both procedures, higher volume SWL providers seemed to have greater diversification of practice, though there was considerable variation. Better understanding of factors driving surgical practice patterns is needed to ensure patients are getting full counseling on their treatment options.

Christopher R. Haas

Urology Resident
Columbia University
New York, New York

A graduate of both Columbia University's college and medical school, Christopher Haas, MD is currently in his PGY-4 research year at Columbia University's urology residency. Graduating magna cum laude with a Bachelor's of Arts degree in music and economics in 2008, Chris found his path to medicine by completing his premedical requirements at Tufts University and gaining acceptance into Columbia University's Medical School in 2011. He was fortunate to continue residency in New York City with outstanding faculty mentors in both endourology and urologic oncology, his two primary fields of interest. Chris is currently pursuing research in endourology under the mentorship of Elias Hyams, MD and Ojas Shah, MD. In his free time, he enjoys playing piano, running, skiing, tennis, and exploring new cities. He is excited and honored to be presenting four posters at his first World Congress of Endourology and also looks forward to exploring Paris!

Alexander Small

Urology Resident
Columbia University
New York, New York

Ojas Shah

Professor of Urology
New York Presbyterian-Columbia University Medical Center
New York, New York

Dr. Ojas Shah is the George F. Cahill Professor of Urology at Columbia University College of Physicians and Surgeons. He also serves as the Director of the Division of Endourology and Stone Disease at Columbia University Medical Center. His clinical and research interests include surgical and metabolic treatments of kidney stone disease, minimally invasive urologic surgery, upper urinary tract urothelial carcinoma (transitional cell carcinoma), ureteral strictures, ureteropelvic junction (UPJ) obstruction, and ureteral/renal reconstructive surgery. He serves as the principal investigator in many clinical research trials regarding the surgical or medical management of stone disease.

He is a graduate of the Honors Program in Medical Education at Northwestern University School of Medicine. He completed his general surgical and urologic training at New York University Medical Center. He spent an additional year at Wake Forest University Health Sciences Center as a fellow in endourology, laparoscopy and metabolic stone disease.

Dr. Shah is a nationally and internationally recognized expert in the medical and surgical management of patients with urinary stone disease. He recently served as a member of the American Urological Association’s Surgical Management of Stones Guidelines Committee. He was also recently appointed to the American Board of Urology’s Examination Committee. He is an active member of the Endourological Society, EDGE (Endourology Disease Group for Excellence) Research Consortium, and ROCK (Research on Calculous Kinetics) Society.

Dr. Shah is an Assistant Editor for the Journal of Urology, the most highly cited and amongst the most respected international journals in the field. He is also co-editor of the 5th Edition of Taneja’s Complications of Urologic Surgery which was released in 2018.

Elias S. Hyams

Assistant Professor of Urology
Columbia University Medical Center, Department of Urology
New York, New York