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NCT Number: NCT07332286

FANS-Assisted Mini-PCNL for Complex Renal Stones

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.

Active, Not Recruiting

This study is active but is not currently recruiting participants.

Key information

Conditions

Kidney Stones Calculi Female Urogenital Diseases Female Urogenital Diseases and Pregnancy Complications Kidney Calculi Kidney Diseases Male Urogenital Diseases Nephrolithiasis Pathological Conditions, Anatomical Pathological Conditions, Signs and Symptoms Urinary Calculi Urogenital Diseases Urolithiasis Urologic Diseases

Age range

18 year–75 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

The First Affiliated Hospital of Guangzhou Medical University

Guangzhou, Guangdong, 510230, China

About this study

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.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

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

Treatment and study plan

FANS-assisted mini-percutaneous nephrolithotomy

Procedure

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

Primary outcomes

  1. Immediate stone-free rate

    Time frame: Postoperative day 0 to 3

    Absence of residual stones or fragments >2 mm detected by non-contrast CT

Secondary outcomes

  1. Stone-free rate at 1 month

    Time frame: Postoperative day 30 (±7 days)

    Absence of residual stones or fragments >2 mm detected by non-contrast CT

  2. Operative time

    Time frame: From skin puncture to completion of the procedure (intraoperative period)

    Total duration of the surgical procedure measured from puncture to completion of the operation

  3. Postoperative pain score

    Time frame: Postoperative day 1

    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.

  4. Postoperative complications

    Time frame: Postoperative day 0 to 30

    Incidence and severity of postoperative complications classified according to the Clavien-Dindo grading system

  5. Length of postoperative hospital stay

    Time frame: Postoperative day 0 to postoperative day 14

    Duration of hospital stay measured from completion of the procedure to hospital discharge

  6. Quality of life score

    Time frame: Baseline and postoperative day 30

    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.

Sponsors and collaborators

Lead sponsor

The First Affiliated Hospital of Guangzhou Medical University

Other

Registry information

Official study title

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

Acronym: FANS-MiniPerc

Important dates

Study start
2025
Primary completion
2026
Study completion
2026
First posted
Jan 12, 2026
Registry last updated
Apr 15, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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