FANS-Assisted Mini-PCNL for Complex Renal Stones

Overview

This prospective pilot study aims to evaluate the feasibility, safety, and preliminary clinical outcomes of a novel mini-percutaneous nephrolithotomy (mini-PCNL) technique integrating a flexible mini-nephroscope with a flexible and navigable suction access sheath (FANS) for the treatment of complex renal stones. Thirty consecutive patients with renal stones ≥2 cm will be prospectively enrolled. All patients will undergo FANS-assisted mini-PCNL. The primary outcome is the immediate stone-free rate assessed by non-contrast CT within 72 hours after surgery. Secondary outcomes include operative parameters, postoperative pain, complications, length of hospital stay, and quality of life. This pilot study is designed to provide preliminary evidence supporting the feasibility and safety of FANS-assisted mini-PCNL and to inform the design of future larger-scale studies.

Conventional mini-PCNL may be limited by restricted access to anatomically challenging calyces and inefficient evacuation of stone fragments when flexible nephroscopy is required. A novel technique integrating a flexible mini-nephroscope with a flexible and navigable suction access sheath (FANS) has been developed to enable flexible intrarenal navigation combined with active suction during antegrade lithotripsy. This prospective pilot study will enroll 30 consecutive patients undergoing FANS-assisted mini-PCNL for complex renal stones. The study focuses on feasibility, safety, and preliminary clinical outcomes, including stone clearance and perioperative morbidity. The results will serve as preliminary data for future confirmatory or comparative clinical trials.