Comparison of monoplanar, cross-table bull's-eye, and a hybrid ultrasound-fluoroscopy technique for renal access in supine PCNL: a cognitive mapping approach.

Abstract

Purpose: Percutaneous needle access is a critical step in percutaneous nephrolithotomy (PCNL). Supine PCNL, favored for its anesthetic and physiological benefits, can be performed using various puncture techniques. This study compared the efficacy and radiation safety of monoplanar, cross-table bull's-eye, and a combined ultrasound (US)-fluoroscopy-guided access technique for supine PCNL.

Methods: Between January 2021 and March 2025, 130 patients undergoing supine PCNL were reviewed in three groups: monoplanar (Group A, n = 41), cross-table bull's-eye (Group B, n = 45), and combined US-fluoroscopy (Group C, n = 44). In Group C, pre-procedural US established a cognitive vectorial roadmap to determine needle trajectory and depth. Punctures were performed under 0° fluoroscopy, with on-demand refinements using 0-30° rotation and cephalad angulation for depth verification. Perioperative outcomes and radiation times were compared.

Results: Total operative time, stone-free (SF) rates, complications, blood transfusion rates, creatinine (Cr) change, hemoglobin (Hb) loss, nephrostomy and hospital stay did not differ significantly among groups (p > 0.05). However, mean fluoroscopy time for successful puncture was significantly lower in the combined US-fluoroscopy group (26.59 s) compared to monoplanar (42.82 s) and cross-table bull's-eye (40.62 s) techniques (p < 0.001).

Conclusion: The combined US-fluoroscopy-guided technique is feasible for supine PCNL and significantly reduces radiation exposure. By integrating US-derived cognitive planning with on-demand fluoroscopic verification, this hybrid approach facilitates efficient needle puncture without compromising procedural precision or clinical success. It serves as a valuable alternative for optimizing radiation safety in urologic practice.