Comparison of ESWL and Mini-PCNL for High-Density Renal Stones in Children

Summary

Pediatric nephrolithiasis is an increasing health problem, with rising prevalence particularly in certain geographic regions. Management options for pediatric renal stones include extracorporeal shockwave lithotripsy (SWL), percutaneous nephrolithotomy (PNL), and retrograde intrarenal surgery. According to the EAU/ESPU guidelines, SWL is recommended as a first-line treatment for most renal stones; however, its success is significantly influenced by stone size, location, and density. High-density renal stones (≥1000 Hounsfield Units) are associated with lower stone-free rates after SWL and higher retreatment rates.

Miniaturized percutaneous nephrolithotomy (mini-PNL) has emerged as an effective alternative, offering high stone-free rates with reduced morbidity compared to standard PNL due to the use of smaller access sheaths. While adult studies have demonstrated superior outcomes of mini-PNL over SWL for high-density renal stones, there is a lack of comparative data in the pediatric population.

This prospective randomized controlled study aims to compare the efficacy and safety of mini-PNL versus SWL in children aged 2 to 12 years with single, non-lower pole, high-density (≥1000 HU), medium-sized (10-20 mm) renal stones. Eligible patients will be randomized into two equal groups to undergo either mini-PNL or SWL under general anesthesia.

The primary outcome is the stone-free rate, defined as no residual stone or residual fragments ≤4 mm on non-contrast computed tomography performed three months after the procedure. Secondary outcomes include operative and fluoroscopy times, hemoglobin drop, length of hospital stay, retreatment and ancillary procedure rates, and postoperative complications graded according to the Clavien-Dindo classification.

The study will be conducted at a single tertiary referral center. All participants' parents or legal guardians will provide informed consent in accordance with Good Clinical Practice guidelines and the Declaration of Helsinki. This study aims to provide evidence to guide optimal management of pediatric patients with high-density renal stones.

Conditions

• Renal Stones
• Calculus
• Pediatric
• Endoscopy

Interventions

PROCEDURE

Miniaturized Percutaneous Nephrolithotomy (mini-PNL)

Mini-PNL: All procedures will be done in the prone position. The target calyx will be punctured using fluoroscopic guidance with an 18-GA sheathed needle, and tract dilatation will be achieved using Amplantz dilators up to 16-18 Fr according to patient age. The holmium: YAG laser will be used to perform the stone fragmentation. Standard 12-Fr rigid nephroscope will be used for stone retrieval and fragmentation. A clamped nephrostomy tube will be placed routinely to reduce the bleeding for 24 h in all cases. The nephrostomy tube and the ureteral catheter will be removed on first and second postoperative days if there will be no complications.

PROCEDURE

Shock Wave Lithotripsy (SWL)

The lithotripsy will be performed by an electromagnetic shockwave lithotripter (Dornier Compact Sigma). The lung and genitourinary fields will be shielded for all patients. Fluoroscopy will be used to localize the stone and to monitor fragmentation.The dispensed shockwave will begin at 14 kV and escalates to its maximum power level of 20 kV. The maximum number of shocks given per session will be between 1000 and 2500 depending on patient age (1000 waves per session for children younger than 5 years and 2500 waves per session for older children, with a frequency of 70 shocks/minute). The SWL session will be stopped when no visible stone is detected, or when tiny fragments are the only visible stone remnants, or when the desired number of shocks has been given.

Sponsors & Collaborators

• Ain Shams University

  lead OTHER

Study Design

Allocation

RANDOMIZED

Purpose

TREATMENT

Masking

TRIPLE

Model

PARALLEL

Eligibility

Min Age

2 Years

Max Age

12 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2023-05-28

Primary Completion

2025-05-20

Completion

2025-09-09

Countries

• Egypt

Study Locations