BANFF, Alberta—Ureteroscopy has replaced extracorporeal shockwave lithotripsy (SWL) as the most commonly used treatment for removing ureteral stones, according to researchers in Ontario, Canada.

Results presented at the Canadian Urological Association’s 2012 annual meeting indicate the use of SWL dropped from 68.5% of all procedures for ureteral stones in 1991 to 33.7% in 2010. Concomitantly, URS use increased from 24.6% to 59.5%.

Study leader Michael Ordon, MD, pointed to several reasons for this trend, including the development of smaller, more flexible ureteroscopes with improved optics that have made the technology more accurate and less prone to complications. In addition, he observed, the advent of holmium:YAG lasers has made URS and stone fragmentation safer and more efficient. Together, these advancements have led the American Urological Association to recognize both URS and SWL as a first-line treatment options for ureteral stones, he noted.

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“There is also the fact that more recently trained urologists have gained much more experience and competence in URS during their residency training, thanks to the above advances and as such are more likely to utilize it once out in independent practice,” said Dr. Ordon, an endourology and minimally invasive surgery fellow at St. Michael’s Hospital and the University of Toronto. “And, specific to Ontario, only three lithotripters are available in the province. Therefore, because of both ease of access and higher reimbursement, many urologists will offer their patients URS instead of SWL.”

While urologists are well aware of the trend to much more URS use, most studies corroborating the anecdotal observations have been physician surveys or single-center series. Many of the studies of URS—which also have documented the efficacy of the approach and low retreatment and complication rates—have involved high-volume centers.

It is for these reasons that Dr. Ordon and several other clinician researchers in Toronto decided to evaluate population-based trends in the treatment of kidney stones. The goal was to objectively document the significant shift from SWL to URS.

Not only did the team verify the change, they also observed a constant rate of percutaneous nephrolithotomy (PCNL) over the 20-year period.

In addition, they confirmed a significant decrease over time in the need for ancillary or repeat treatment (23.1% vs. 15.3% of procedures), a trend related to the fact that URS was associated with less retreatment than SWL (10.6%-13% vs. 22%-30%).

However, Dr. Ordon’s group observed an increase in hospital readmissions within seven days of treatment (7.27%-10.8%) due to higher readmission rates with URS than SWL (12%-14% vs. 4%-8%). The increase in emergency department visits within seven days of treatment that the team found  (7.1% vs. 10.5%) also was driven by higher rates of need for emergent care following URS (9%-13.5% vs. 5.5%-7.5%).

The results are corroborated and bolstered by a study published online in the Journal of Urology on June 12. A team from the James Buchanan Brady Urological Institute, Johns Hopkins Medical Institutions, Baltimore, used a review of studies published from 1995 to 2012 to compare the cost-effectiveness of kidney-stone removal via URS, SWL, and PCNL. For both proximal and distal stones, the study revealed a higher stone-free rate and lower cost with URS compared with SWL. The study also found a higher cost, albeit with a higher stone-free rate, with PCNL than with either URS or SWL.