PD37-01: A randomized, single-center, clinical trial comparing robotic-assisted fluoroscopic-guided with ultrasound-guided renal access for percutaneous nephrolithotomy

Kazumi Taguchi*, Shuzo Hamamoto, Takahiro Yanase, Yasuhito Sue, Tatsuya Hattori, Teruaki Sugino, Teruaki Sugino, Atsushi Okada, Takahiro Yasui, Nagoya, Japan

Introduction: Renal access during percutaneous nephrolithotomy (PCNL) is a crucial step in achieving favorable surgical outcomes. While fluoroscopy and ultrasound (US) guidance require certain learning curves, robotic technology with artificial intelligence could provide a solution for shortening these learning curves, leading to better results. We have previously reported the efficacy of robotic-assisted fluoroscopic (RAF)-guided renal access for PCNL using an automated needle target with X-ray (ANT-X) in a benchtop study and a case series. In this study, we conducted a randomized, single-center, clinical trial comparing surgical outcomes between RAF- and US-guided renal access in mini-PCNL.

Methods: Patients who underwent mini-PCNL for large renal stones between January 2020 and May 2021 were recruited for this study. Randomization was performed by adjusting for age, sex, laterality, stone burden, and hydronephrosis grade. ANT-X® was used for fluoroscopic-guided renal access in the RAF group, whereas ARIETTA® was used for US-guided access. PCNLs were mainly performed by residents using a pneumatic lithotripsy system with 16.5/17.5Fr tracts. The primary endpoint was the stone-free rate (SFR), and the secondary endpoints were complication rate, parameters during renal access, and fluoroscopy time.

Results: A total of 71 patients (US group=35, RAF group=36) were enrolled in this study. No significant differences were observed in preoperative factors between the two groups. The SFR 3 months after surgery in the US and RAF groups was 70.6% and 83.3 %, respectively (p=0.26). No differences were observed in the mean surgical, percutaneous access, and fluoroscopic durations, as well as the overall complication rate between the two groups (p=0.458, p=0.261, p=0.425, and p=0.396, respectively) (Table 1). Consistent with the univariate analysis result, multivariate analysis revealed that the RAF guidance reduced the mean number of needle punctures by 32% compared to the US guidance (p=0.035).

Conclusions: This randomized clinical trial demonstrated that RAF-guided renal access had comparable surgical outcomes with US-guided renal access during mini-PCNL. ANT-X® may be beneficial for trainees to achieve safe tract creation with a short learning curve.

Source of Funding: none