WCET 2024: Assessment Of Post-Operative Outcomes Following Robotic assisted Mini- Percutaneous Nephrolithotomy With The Monarch™ Platform, Urology

(UroToday.com) At the WCET 2024 conference, Dr. Margaret Knoedler unveiled promising early results of robotic-assisted mini-percutaneous nephrolithotomy (mini-PCNL) using the MONARCH™ Platform. The MONARCH™ Platform, developed by Johnson & Johnson MedTech, represents a significant advancement in the field, designed to enhance percutaneous access and streamline the treatment of large renal stones. A retrograde ureteroscope is inserted and operated by the surgeon using a handheld controller.


image-0.jpg

Through the ureteroscope, working instruments like the laser and basket are deployed, while stone fragments are extracted via a flexible suction catheter inserted percutaneously. Electromagnetic guidance facilitates percutaneous access, with the user interface displaying a bullseye target to aid the surgeon in accurately positioning the needle. Once the needle pierces the collecting system, it becomes visible in the ureteroscopic view.

image-1.jpg

In this subset analysis of a larger study, Dr. Knoedler and her team explored the clinical and procedural outcomes of this innovative technology. The study, conducted under an IRB-approved protocol, involved a prospective, multicenter, single-arm observational design. A total of up to 60 patients were slated for inclusion, with a focus on assessing the safety, efficacy, and procedural efficiency of the MONARCH™ Platform in performing robotic-assisted mini-PCNL.

Since submission, five additional patients have undergone the procedure at the University of Wisconsin, resulting in a total of 8 patients presented at the conference. The average preoperative stone burden was 3.3 cm (1.5-7.1) and their average procedure time was 222 minutes.

image-2.jpg

The robotic-assisted mini-PCNL successfully provided percutaneous access directly into the renal papilla in each case with the electromagnetic guidance. In all cases, the percutaneous access and trans calyceal access rates were 100%. Of note, there was only a single patient with fluid extravasation.

image-3.jpg

The study had a follow up window of 30 day in which for all participants combined, there was a 98% reduction in stone burden. Four patients (50%) had a 5 mm or less stone burden during the follow up.

image-4.jpg

To close, Dr. Knoedler explained that the initial experience with the MONARCH™ Platform represents a significant advancement in robotic-assisted mini-PCNL. She reported that percutaneous access was successfully achieved in all eight patients treated thus far, with the majority of stone fragments and debris effectively removed using robotic-assisted control. These findings underscore the platform’s potential to improve surgical outcomes and patient care, offering expanded capabilities for the safe and effective treatment of urological patients. Further research is expected to validate these promising results in a larger patient population.

image-5.jpg

During the question-and-answer session, an audience member remarked on the difficulty of docking the robot during benchtop testing. They inquired about how long it took the investigators to dock the robot, the team's experience and the learning curve involved in using the machine. Dr. Knoedler acknowledged that docking did take some time, but noted it was far less cumbersome compared to docking a da Vinci robot. She emphasized the user-friendly nature of the MONARCH™ platform, explaining that while it added a little time to the case, it was not a significant burden in her experience.

Another audience member praised Dr. Knoedler for the CT images shown during the experiment and asked how the team selected calyces when determining the ideal entry point into the kidney. Dr. Knoedler agreed that physicians should typically choose a calyx without a stone for entry. However, she mentioned that in certain situations, she might remove some stones first to gain access if she felt the calyx was a particularly optimal entry point—though this could add extra operative time. She also highlighted that direct access to the stone is often unnecessary with this technology, as an entrance through an adjacent calyx can be sufficient, as the flexible suction catheter would allow the surgeon to reach the stone, contrasting with the rigid approach of traditional PCNL.

A final question from the audience addressed why Dr. Knoedler encountered remnant stones despite using this advanced technology. She attributed this to being relatively new to the platform and the associated learning curve. In this specific case, she explained, the remaining fragments may have appeared as dust during surgery, but after settling, a few additional stones were discovered in the lower pole.

Dr. Knoedler’s preliminary findings suggest that the MONARCH™ Platform holds great potential for expanding the capabilities of urologists, particularly in institutions where percutaneous access is not routinely performed independently. This robotic-assisted approach offers a new level of precision and efficiency in treating nephrolithiasis, paving the way for safer and more effective treatment options for patients with large renal stones.

Presented by: Margaret Knoedler, M.D., University of Wisconsin

Co-Authors: Emily Serrell, Nancy Sehgel, Brandon Cowen, Camilla Gomes, Paul Morris, Stephen Nakada

Moderated by: William W. Roberts, III, M.D., and Roger L. Sur, M.D.

Written by: Seyed Amiryaghoub M. Lavasani, B.A., University of California, Irvine, @amirlavasani_ on Twitter during the 2024 World Congress of Endourology and Uro-Technology (WCET) Annual Meeting, August 12 -16, 2024, Seoul, South Korea