Within the field of urology, it is well recognized that technology is advancing rapidly, with progress occurring across all areas on a daily basis. Retrograde intrarenal surgery (RIRS) is no exception. In an effort to improve outcomes, intrarenal pressure (IRP) has recently been highlighted as a critical factor in intracorporeal lithotripsy.^1,2 Elevated IRP may result in renal injury, fluid reflux and extravasation, dissemination of infection, urinary sepsis, postoperative pain, and—most feared by surgeons performing these procedures—septic shock. Values < 30 mm Hg have been suggested to mitigate these adverse effects.^1,2

Among the factors contributing to increased IRP, the irrigation system used—and, consequently, the irrigation flow rate—plays a crucial role. It has been shown that, when comparing pressurized-bag irrigation with hand-operated irrigation pumps, manual systems can significantly increase IRP and may therefore be associated with higher rates of infectious complications.³ In addition, the use of high-power lasers and the treatment of larger stone burdens underscore the need to increase irrigation flow to improve visualization, facilitate fragment clearance, and simultaneously control intrarenal temperature.

To address this issue, new devices such as flexible and navigable suction ureteral access sheaths, thinner ureteroscopes, and direct in-scope suction have recently garnered increasing attention. These technologies can improve the stone-free rate (SFR), help maintain low IRP, and ensure a clear visual field. One example is the development of new flexible ureteroscopes capable of real-time IRP sensing.⁴ This, in turn, has prompted evaluation of irrigation and suction methods. In parallel, and leveraging advances in artificial intelligence, new technologies have been developed that can modulate irrigation flow or suction based on target IRP values.

A recent publication by Yamazaki et al⁵ describes a foot-operated device (Peditrol, Wismed) that allows a single operator to control irrigation flow. Peditrol enables intermittent manual increases in flow to assist with stone mobilization. The study was conducted in synthetic kidney models using suction ureteral access sheaths and continuous gravity irrigation, with conventional RIRS serving as the control group. The authors concluded that Peditrol facilitated efficient and safe stone extraction while maintaining IRP within acceptable limits.

To simplify and improve surgical efficiency, it appears preferable to use devices that sense IRP and automatically adjust the irrigation flow rate through a feedback mechanism, maintaining IRP within predefined safety thresholds—similar to the way the pneumoperitoneum is regulated in laparoscopic surgery. The first report of RIRS with intelligent pressure control was published in 2016 by Zhu et al⁶ in a porcine model. Since then, multiple technological innovations have emerged to enable intelligent automated control of irrigation. Glienke et al⁷ described the use of a prototype fluid management system that adjusts flow rate based on pressure feedback in synthetic models. In their work, this technology was reported as an effective method to maintain appropriate IRP. Another in vitro study developed a similar automated irrigation system in which flow regulation was based on IRP sensed via a fiber optic pressure sensor.⁸

More recently, Boston Scientific developed Asurys, a fluid management system designed to integrate with the single-use LithoVue Elite flexible ureteroscope and the StoneSmart console. In LithoVue Elite mode, intrarenal pressure is measured by a tip-mounted sensor on the ureteroscope and displayed on the StoneSmart console. Asurys does not measure pressure directly; instead, it uses the intraluminal pressure signal from the ureteroscope to adjust or suspend irrigation when the surgeon-defined pressure threshold is approached. As an additional innovation, Asurys incorporates a transient flow-boost function (“flow feature”), which allows temporary increases in flow via buttons on the ureteroscope handle, with configurable intensity—similar to the previously described Peditrol device. The first human cases were performed in Chile in 2025 by our group and were presented and officially launched at the 2025 AUA Annual Meeting in Las Vegas. Its commercial launch is anticipated in 2026.

Yang et al⁹ reported their experience with a novel patented platform that provides intelligent irrigation and suction control based on intrarenal pressure. This technology has been progressively adopted in hospitals in China with promising results. The platform senses IRP via a ureteral access sheath. A baseline irrigation flow is set, and the system then automatically adjusts the level of negative suction pressure according to the target IRP value sensed within the collecting system, which in their studies was fixed at 30 mm Hg. In their work, the authors conducted a nonrandomized comparative analysis of this new system vs microchannel percutaneous nephrolithotomy (also using the same automated irrigation-suction platform) for 2- to 3-cm renal calculi. They demonstrated results favoring RIRS, including shorter hospital stay, a higher SFR at 1 month postoperatively, smaller decreases in hemoglobin, less pain, and similar complication rates, with no severe infectious complications. They concluded that these favorable outcomes could be explained, at least in part, by the intelligent irrigation and suction system. Another study compared the same platform in RIRS vs conventional RIRS and showed a significantly improved SFR without increasing complications, length of hospitalization, or operative time.³ This device appears to allow higher irrigation flow rates while maintaining controlled IRP.

Huang et al¹⁰ recently published their results with a similar system, but incorporating a flexible ureteral access sheath. They compared a front-end flexible intelligent pressure-control ureteral access sheath with conventional RIRS. As with the previous group, they concluded that this technology improves surgical efficiency, enhances recovery, and reduces the risk of infection during RIRS, even in the setting of infection-related renal calculi.

Technology continues to advance, and urology is keeping pace. These developments and studies prompt us to re-examine the current limits of RIRS, with the potential to extend its indications to larger stone burdens while maintaining comparable outcomes and without increasing procedure-related complications. Recognizing the importance of irrigation flow rate and pressure control, it is expected that, over time, more and newer devices will be designed to achieve safer and more efficient surgery.

Conflicts of Interest: No payments or financial compensation was received by the investigators for conducting this research. Dr Juan Fulla and Dr José Salvadó serve as proctors for Boston Scientific.