High-powered lasers expand ureteroscopic options for patients with kidney stones

Advances in laser technology, acoustic wave devices, and ultrasonic stone manipulation are reshaping the management of urolithiasis, offering clinicians new options to treat complex patients more safely and with less procedural burden, according to Dinesh Singh, MD, an associate professor of urology, Endourology Chief, Urology; director of Laparoscopy & Endourology, Urology; and director of the Endourology Fellowship, Urology at Yale School of Medicine in New Haven, Connecticut.

Two high-powered laser platforms—holmium and thulium—have emerged as the dominant technologies for ureteroscopic lithotripsy, each with distinct performance profiles. Thulium lasers operate at high pulse frequencies, making them well suited for stone dusting, and can be plugged into a standard outlet. However, they are less effective for fragmentation when the goal is to break stones into extractable pieces, and they generate more heat—a factor Singh noted has been associated with a higher rate of reported thermal injuries to the renal collecting system. Holmium lasers require a dedicated, often retrofitted outlet in the operating room but offer both high-frequency capability and effective fragmentation, making them more versatile across stone types and treatment strategies.

One of the most clinically significant applications Singh highlighted involves patients on long-term anticoagulation.

"Increasingly, we're seeing a lot of patients who are on anticoagulants—for stroke prevention, cardiac stents, and a plethora of other reasons—and many of those patients are on them for important prevention reasons," he said. "Coming off those anticoagulants presents a significant risk." Historically, patients in this category with larger stones were candidates for percutaneous nephrolithotomy, a procedure that involves a skin incision and renal puncture carrying inherent bleeding risk. High-powered laser platforms now allow larger stones to be addressed ureteroscopically without interrupting anticoagulation therapy.

"That's been an area where I found it most useful, and I'm employing it increasingly often in that increasing subset of patients," Singh said.

On the non-invasive front, Break Wave lithotripsy represents an early but promising departure from conventional extracorporeal shock wave lithotripsy. Rather than delivering a single high-energy shock, the technology uses lower-energy bursts of ultrasound to fragment stones. A first-in-human study published in the Journal of Urology in October 2024—led by investigators including Ben H. Chew, MD, MSc, FRCSC, Jonathan D. Harper, MD, and Thomas Chi, MD, MBA—enrolled approximately 44 patients with a mean stone size of 6 mm and mean Hounsfield unit of 850. Complete fragmentation was achieved in roughly 50% of patients; among the remainder, approximately half had residual fragments smaller than 2 mm. Procedures were completed in approximately 30 minutes, most patients did not require anesthesia, and the technology was used in an office rather than an operating room setting.

"We're early in the phases of identifying its role," Singh said, "but it's important to be aware of this new technology that may play a valuable role in treatment of stone disease."

Ultrasonic propulsion, advanced by researchers at the University of Washington including Harper, takes a different approach—using focused ultrasound in the office setting to reposition stones into a more favorable anatomic location to facilitate spontaneous passage. Singh characterized the technology as early-stage but conceptually compelling, with ongoing research needed to define its clinical role.