FANS-Assisted Mini-PCNL for Complex Renal Stones (FANS-MiniPerc)

Mini-percutaneous Nephrolithotomy With a Flexible Mini-nephroscope and a Flexible and Navigable Suction Access Sheath for Complex Renal Stones: A Prospective Pilot Study

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.

Study Overview

• Status: Active, not recruiting
• Conditions: Kidney Stones
• Intervention / Treatment: Procedure: FANS-assisted mini-percutaneous nephrolithotomy

Detailed Description

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.

• Study Type: Interventional
• Enrollment (Estimated): 30
• Phase: Not Applicable

Contacts and Locations

Study Locations

• China
  • Guangdong
    • Guangzhou, Guangdong, China, 510230
      • The First Affiliated Hospital of Guangzhou Medical University

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult; Older Adult
• Accepts Healthy Volunteers: No

Description

Inclusion Criteria:

• Adults aged 18 to 75 years
• Patients with renal stones measuring 2 cm or larger in maximum diameter
• American Society of Anesthesiologists (ASA) physical status classification I-III
• Planned to undergo mini-percutaneous nephrolithotomy
• Able and willing to provide written informed consent

Exclusion Criteria:

• Uncontrolled urinary tract infection at the time of surgery
• Known bleeding tendency or coagulation disorders
• Contraindication to general anesthesia
• Pregnancy or breastfeeding

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm

Intervention / Treatment

Experimental: FANS-assisted mini-PCNL; Mini-percutaneous nephrolithotomy performed using a flexible mini-nephroscope combined with a flexible and navigable suction access sheath to facilitate flexible access and active stone fragment evacuation.

Procedure: FANS-assisted mini-percutaneous nephrolithotomy; The procedure consists of mini-percutaneous nephrolithotomy (mini-PCNL) performed with the assistance of a flexible mini-nephroscope and a flexible and navigable suction access sheath (FANS). Following standard percutaneous renal access and initial stone fragmentation using a rigid nephroscope, a flexible mini-nephroscope is introduced through the percutaneous tract to access calyces that are difficult to reach with rigid instruments. Holmium:YAG laser lithotripsy is then performed under flexible endoscopic visualization. The flexible and navigable suction access sheath allows simultaneous irrigation and adjustable negative-pressure suction, enabling continuous evacuation of stone fragments during lithotripsy. Suction strength can be regulated intraoperatively to maintain a clear endoscopic field and facilitate controlled fragment removal. This procedure is applied to all participants in this prospective pilot study and aims to evaluate the feasibility and safety of flexible suction; Other Names: Mini-PCNL using a flexible mini-nephroscope with suction access sheath

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Immediate stone-free rate	Absence of residual stones or fragments >2 mm detected by non-contrast CT	Postoperative day 0 to 3

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stone-free rate at 1 month	Absence of residual stones or fragments >2 mm detected by non-contrast CT	Postoperative day 30 (±7 days)
Operative time	Total duration of the surgical procedure measured from puncture to completion of the operation	From skin puncture to completion of the procedure (intraoperative period)
Postoperative pain score	Postoperative pain assessed using the Visual Analog Scale (VAS), ranging from 0 to 10, where 0 indicates no pain and 10 indicates the worst pain imaginable.	Postoperative day 1
Postoperative complications	Incidence and severity of postoperative complications classified according to the Clavien-Dindo grading system	Postoperative day 0 to 30
Length of postoperative hospital stay	Duration of hospital stay measured from completion of the procedure to hospital discharge	Postoperative day 0 to postoperative day 14
Quality of life score	Health-related quality of life assessed using the Wisconsin Stone Quality of Life (WISQOL) questionnaire, which consists of 28 items scored on a 5-point Likert scale. Total scores range from 0 to 140, with higher scores indicating better quality of life.	Baseline and postoperative day 30

Collaborators and Investigators

• Sponsor: The First Affiliated Hospital of Guangzhou Medical University

Study record dates

Study Major Dates

• Study Start (Actual): December 19, 2025
• Primary Completion (Actual): April 12, 2026
• Study Completion (Estimated): April 30, 2026

Study Registration Dates

• First Submitted: December 19, 2025
• First Submitted That Met QC Criteria: January 9, 2026
• First Posted (Actual): January 12, 2026

Study Record Updates

• Last Update Posted (Actual): April 15, 2026
• Last Update Submitted That Met QC Criteria: April 12, 2026
• Last Verified: April 1, 2026

More Information

Terms related to this study

• Keywords: kidney stone; PCNL; mini-PCNL; FANS
• Additional Relevant MeSH Terms: Urogenital Diseases; Male Urogenital Diseases; Calculi; Pathological Conditions, Anatomical; Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urolithiasis; Urinary Calculi; Nephrolithiasis; Pathological Conditions, Signs and Symptoms; Kidney Calculi
• Other Study ID Numbers: ES-2025-252-02 (Other Identifier: The First Affiliated Hospital of Guangzhou Medical University)

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO
• IPD Plan Description: Individual participant data will not be shared, as this is a single-center prospective pilot study with a small sample size, and the data will be used primarily for exploratory and hypothesis-generating purposes.

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No