Modified Mini-PCNL Versus Standard PCNL for Complex Kidney Stones

The First Affiliated Hospital of Guangzhou Medical University1,380 enrolled

Overview

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.

Study Type

INTERVENTIONAL

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

SINGLE

Enrollment

1,380

Conditions

Kidney Stones Complex Renal Calculi

Interventions

20 Fr Modified Mini Percutaneous NephrolithotomyPROCEDURE

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.

24 Fr Standard Percutaneous NephrolithotomyPROCEDURE

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.

Eligibility

Sex: ALLMin age: 18 YearsMax age: 70 Years

Medical Language ↔ Plain English

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.

Outcomes

Primary Outcomes

Immediate Stone-Free Rate

Proportion 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.

Time frame: Within 72 hours after surgery

Secondary Outcomes

Stone-Free Rate at 3 Months

Proportion of participants who achieve stone-free status at 3-month follow-up according to low-dose noncontrast CT.

Time frame: 3 months after surgery

Length of Hospital Stay

Number of days from the day of surgery to the day of hospital discharge, rounded to the nearest whole day.

Time frame: From surgery to hospital discharge, assessed up to 30 days after surgery