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Modified Mini-PCNL Versus Standard PCNL for Complex Kidney Stones

Modified Mini Percutaneous Nephrolithotomy Versus Standard Percutaneous Nephrolithotomy for the Treatment of Complex Renal Calculi: A Multicenter Randomized Controlled Trial

Status
Recruiting
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07697677
Acronym
MIMIC-PCNL
Enrollment
1380
Registered
2026-07-13
Start date
2026-07-15
Completion date
2027-09-14
Last updated
2026-07-13

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Complex Renal Calculi, Kidney Stones

Keywords

Percutaneous Nephrolithotomy, Mini-PCNL, Standard PCNL, Modified Mini-PCNL, Complex Renal Stones, Stone-Free Rate, Randomized Controlled Trial

Brief summary

Kidney stones that are large or complex are often treated with percutaneous nephrolithotomy, also called PCNL. Standard PCNL uses a larger access tract and is effective for removing complex kidney stones, but it may be associated with more bleeding, pain, and recovery burden. Modified mini-PCNL uses a smaller access tract and may reduce surgical trauma while maintaining a similar stone clearance rate. This multicenter randomized trial will compare modified mini-PCNL using a 20 Fr access sheath with standard PCNL using a 24 Fr access sheath in adults with complex renal stones. About 1,380 participants from 8 urology centers will be randomly assigned to receive one of the two procedures. The main purpose of the study is to determine whether modified mini-PCNL is not worse than standard PCNL in achieving stone-free status shortly after surgery. Stone-free status will be assessed by low-dose noncontrast CT within 72 hours after surgery. The study will also compare stone-free status at 3 months, complications, operation time, length of hospital stay, need for additional procedures, and quality of life.

Interventions

PROCEDURE20 Fr Modified Mini Percutaneous Nephrolithotomy

Modified mini percutaneous nephrolithotomy performed with a 20 Fr access sheath and F17 Hawk nephroscope. Stone fragmentation may be performed using pneumatic lithotripsy, Ho:YAG laser, or thulium fiber laser according to the standardized surgical protocol.

PROCEDURE24 Fr Standard Percutaneous Nephrolithotomy

Standard percutaneous nephrolithotomy performed with a 24 Fr access sheath and F20.8 Wolf nephroscope. Stone fragmentation may be performed using pneumatic lithotripsy, Ho:YAG laser, or thulium fiber laser according to the standardized surgical protocol.

Sponsors

The First Affiliated Hospital of Guangzhou Medical University
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
SINGLE (Outcomes Assessor)

Eligibility

Sex/Gender
ALL
Age
18 Years to 70 Years
Healthy volunteers
No

Inclusion criteria

1. Adults aged ≥18 years. 2. Serum creatinine ≤133 μmol/L. 3. American Society of Anesthesiologists (ASA) physical status classification I-III. 4. S.T.O.N.E. score ≥8. 5. Complex renal stones confirmed by noncontrast computed tomography, including stone surface area \>1500 mm², multiple calyceal stones, partial or complete staghorn calculi, or complex anatomical conditions. 6. Patients who provide written informed consent and agree to undergo either modified mini-percutaneous nephrolithotomy or standard percutaneous nephrolithotomy.

Exclusion criteria

1. Solitary kidney. 2. Morbid obesity (body mass index ≥35 kg/m²). 3. Previous renal transplantation or urinary diversion. 4. Congenital abnormalities of the urinary tract. 5. Pregnancy. 6. Uncorrected coagulopathy. 7. Active urinary tract infection.

Design outcomes

Primary

MeasureTime frameDescription
Immediate Stone-Free RateWithin 72 hours after surgeryProportion of participants who achieve stone-free status after surgery. Stone-free status is defined as no residual stone visualized under endoscopy and no residual stone fragments, or residual fragments ≤2 mm, on low-dose noncontrast CT with 2-mm slice thickness.

Secondary

MeasureTime frameDescription
Stone-Free Rate at 3 Months3 months after surgeryProportion of participants who achieve stone-free status at 3-month follow-up according to low-dose noncontrast CT.
Length of Hospital StayFrom surgery to hospital discharge, assessed up to 30 days after surgeryNumber of days from the day of surgery to the day of hospital discharge, rounded to the nearest whole day.

Countries

China

Contacts

CONTACTYongda Liu, Doctor
13719007083@163.com+020-83062923

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jul 14, 2026