Robot-Assisted Fluoroscopy Versus Ultrasound-Guided Renal Access for Nephrolithotomy: A Phantom Model Benchtop Study

Objectives: To evaluate the feasibility of robot-assisted fluoroscopy-guided (RAG) puncture and to compare RAG puncture, utilizing a novel robot system for percutaneous renal access, with ultrasound-guided (USG) puncture. Materials and Methods: We conducted a benchtop study with a renal phantom model using the automated needle targeting with an X-ray system. Seventeen urologists participated in this study and performed RAG and USG phantom punctures. The number of needle punctures, device setup time, and fluoroscopic exposure duration were recorded for the analyses. Results: The single puncture success rates of the RAG and USG punctures were 100% and 70.6%, respectively (p = 0.021). The median needle puncture time of RAG puncture was 24% shorter than that of USG puncture (35.0 vs 46.0 seconds; p < 0.001), and the median device setup time of RAG puncture was a minute longer than that of USG puncture (93.0 vs 30.5 seconds; p < 0.001). The median duration of fluoroscopic exposure of RAG puncture was longer than that of USG puncture (38.0 vs 6.5 seconds; p < 0.001). The surgeon's self-assessment results demonstrated that the participating urologists found RAG puncture to be safer and have better visibility than USG puncture; they were also more satisfied with RAG puncture. Subanalysis revealed that, in the RAG group, the attending surgeons had shorter total procedural time than the residents (p = 0.045). Conclusion: RAG puncture showed comparable results and accuracy rates with USG puncture for renal access.