PD40-12: Robotic-Assisted Electromagnetic Guidance Minimizes Radiation Exposure in Gaining Percutaneous Access for Nephrolithotomy: A Cadaveric Study with Novices

Mitchell Humphreys*, Kevin Wymer, Phoenix, AZ, Ben Chew, Vancouver, Canada, Janet Zhen, Redwood City, CA, Fuad Elkhoury, Los Angelas, CA, Sri Sivalingam, Cleveland, OH, Matthew Dunn, Santa Monica, CA, Michael Borofsky, Minneapolis, MN

Introduction: Fluoroscopy plays a big role in endourologic stone procedures and intra-operative radiation exposure poses risks to the patient, surgeon, and staff. Fluoroscopic guidance is the most utilized imaging modality for obtaining access for percutaneous nephrolithotomy (PCNL).  Radiation usage may also be higher by urologists who are less experienced. In this study, radiation use is compared while gaining percutaneous access in a cadaveric model, using either fluoroscopy or a novel robotic-assisted electromagnetic (EM) method in a cohort of novice urologist.

Methods: Seven novices (individuals who use IR for access, or gain percutaneous access <24 times/year, or have gained access <30 times after training) used robotic-assisted EM-guidance provided by the Monarch® Platform, Urology (Auris Health, Inc., Redwood City, CA) to obtain upper pole, mid kidney, and lower pole access in a modified supine position vs. the same tasks in a prone position using fluoroscopy in a human cadaver. Total radiation time and dosage, defined as from pyelogram to wire insertion, and access radiation time and dosage, defined as from needle insertion to wire insertion, were measured.  Statistical comparisons were made using paired t-tests.

Results: Robot-assisted EM-guidance decreased total radiation time (0.11±0.01 min vs. 1.30±0.33 min, mean ±SEM, p<0.05) and total radiation dosage (1.00±0.15 mGy vs. 5.43±0.88 mGy, p<0.01), compared to fluoroscopy-guided navigation (Figure 1). Additionally, robotic-assisted EM-guidance reduced access radiation time (0.08±0.05 min vs. 1.08±0.24 min, p<0.01) and access radiation dosage (0.25±0.11 mGy vs. 4.25±0.86 mGy, p<0.01) compared to fluoroscopic-guidance.

Conclusions: Robotic-assisted EM-guidance provided by the Monarch® Platform robotic system decreased radiation exposure when compared to fluoroscopic-guidance during percutaneous access in novice urologists with limited access experience. Keeping in mind the principals of ALARA, these limited data suggest that this novel technology could have significant benefits for patients and providers alike.

Source of Funding: Johnson & Johnson