The use of robotics in urology has redefined the surgical standard of care for many diseases but so far has had limited utility in the surgical management of urinary tract stones. Currently, there are only a handful of circumstances where traditional robotic surgery is indicated or advantageous in the management of stone disease. These include unique situations such as renal stones in the setting of ureteropelvic junction obstruction undergoing pyeloplasty or stones in calyceal diverticuli. In most instances minimally invasive standard approaches such as ureteroscopy and percutaneous nephrolithotomy are used preferentially. However, this may soon change with the introduction of novel concepts using robotic solutions to address some of the existing challenges and deficiencies in endourological stone removal.

A potential application of robotics being explored for endourology is transitioning from manually controlled ureteroscopy to robotic controlled instrumentation. Robotic flexible ureteroscopy could have several potential advantages compared to the current standard of care. The ability to control the scope remotely could afford the surgeon an opportunity to operate at a greater distance from the C-Arm thereby decreasing surgeon exposure to ionizing radiation. Another potential advantage is improved ergonomics as performing flexible ureteroscopy can place considerable strain on the shoulder, elbow and wrist, increasing the potential risk for musculoskeletal disorders among surgeons. A third would be improved precision of movements, theoretically allowing the surgeon greater maneuverability around the kidney and potential to more easily target and treat stones with lasers.

Currently, the most well-studied system for this purpose is the Roboflex™ platform (ELMED Medical Systems, Turkey), which allows docking of a traditional endoscope that can be controlled and maneuvered in a robotic fashion. A recent analysis assessed outcomes among 240 consecutive patients undergoing ureteroscopy at a tertiary stone center and demonstrated outcomes in line with reported data for conventional ureteroscopy with a less than 1% technical failure rate of using the robotic system. The authors reported favorable ergonomics with the device and were able to increase the distance from the C-Arm for these cases decreasing radiation exposure, although these outcomes were not formally assessed. ¹

It is conceivable that future generations of ureteroscopes could be designed specifically for robotic control potentially allowing greater degrees of scope deflection and maneuverability not currently feasible with manually controlled scopes. An example of this concept is in the field of bronchoscopy where robotically controlled endoscopes have recently been introduced to assist in scope navigation to the peripheral airway. A common indication for bronchoscopy is attempting to biopsy lung lesions, yet this can be a technical challenge as the pathway into the peripheral airway is often difficult to navigate owing to the branched configuration, the need to deflect the bronchoscope in multiple directions and the progressively smaller size of the subsegmental bronchi. Robotically guided flexible endoscopes have shown potential to improve scope maneuverability, precision, and reach otherwise challenging areas of the lung more easily all while being controlled from a handheld controller. ²

While such fully robotic controlled endoscopes are not currently clinically available for use in urological surgery, the concept has proven to be feasible. Desai et al used one such system (Auris Health, Redwood City, California) in a first-in-man study demonstrating technical feasibility of performing robotic controlled flexible ureteroscopy with laser lithotripsy to treat 16 patients. ³ A novel prototype for a fully robotic flexible ureteroscopic system that allows for scope control and also uses haptic technology to provide some measure of force feedback as well as intrarenal pressure monitoring has also been described. ⁴

Another area of interest in applying robotics toward stone disease is in percutaneous renal surgery. One of the most substantial barriers in percutaneous nephrolithotomy (PCNL) is in obtaining renal access as evidenced by the fact that a minority of urologists obtain their own access. Robotic assistance has been postulated as a technology capable of helping obtain precise, efficient access while minimizing fluoroscopic exposure and complications. Image guided robotic surgical navigation systems are becoming more widely available across several surgical fields, whether it be assisting with more precise screw placement during spine surgery or aiding in alignment of surgical pins during orthopedic joint replacement. The potential for such a system to assist in needle placement for PCNL is clear.

Recently, the automated needle targeting with x-ray (ANT-X) robot-assisted device has been developed. This device uses image registration to automatically align and target a desired calyx using artificial intelligence and can even compensate for respiratory movement. In preclinical studies it has shown potential for reduced radiation exposure and high success rates with high surgeon satisfaction scores compared to ultrasonographic access among a small cohort of residents and attendings. This system has been used successfully in a pilot study among 19 patients undergoing PCNL where there was a median of only 1 attempt required to successfully achieve access with a median needle insertion time of 3.6 minutes (including device set up), only 10 seconds of which was actual needle alignment. ⁵

It is likely that improvements in robotic technology will continue to occur at a rapid pace over the coming years with a goal of alleviating existing obstacles for surgeons. The potential for robotic solutions to be increasingly applied toward endourological stone removal is clear and the future is exciting. At the same time it remains imperative that these solutions deliver equivalent and ideally superior outcomes for patients without compromising cost, quality or safety.

Dr. Borofsky is a consultant for Boston Scientific and Auris Health.