Acoustic Impedance Matching in ESWL Coupling

Acoustic Impedance Matching in ESWL: A Comparative Analysis of Hypotonic, Isotonic and Hypertonic Coupling Fluids

The purpose of this study is to investigate the effect of different salt concentrations (tonicity) in the coupling fluid used during Extracorporeal Shock Wave Lithotripsy (ESWL). The study compares three types of coupling fluids: hypotonic (degassed water), isotonic (0.9% NaCl), and hypertonic (3% NaCl) solutions. Researchers aim to determine which solution provides the best stone fragmentation success while minimizing procedure-related pain and skin complications.

Study Overview

• Status: Completed
• Conditions: Kidney Stones
• Intervention / Treatment: Procedure: Hypotonic degassed water coupling; Procedure: Isotonic (0.9% NaCl) coupling; Procedure: Hypertonic (3% NaCl) coupling

• Study Type: Interventional
• Enrollment (Actual): 294
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Turkey (Türkiye)
  • Konya, Turkey (Türkiye), 42020
    • University of Health Sciences, Konya City Hospital

Participation Criteria

Eligibility Criteria

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

Description

Inclusion Criteria:

Patients with kidney stones measuring 5-20 mm.

Patients scheduled for ESWL treatment.

Age 18 and older

Exclusion Criteria:

Pregnancy.

Uncorrected bleeding disorders.

Active urinary tract infection.

Anatomical abnormalities preventing ESWL.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Treatment
• Allocation: Non-Randomized
• Interventional Model: Parallel Assignment
• Masking: Double

Number of Arms

3

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Active Comparator: Hypotonic Group; Patients in this group received extracorporeal shock wave lithotripsy (ESWL) using hypotonic degassed water as the coupling fluid. (n=97)	Procedure: Hypotonic degassed water coupling; Hypotonic degassed water was used as the coupling fluid during the ESWL procedure.
Experimental: Isotonic Group; Patients in this group received extracorporeal shock wave lithotripsy (ESWL) using 0.9% NaCl (isotonic) solution as the coupling fluid. (n=99)	Procedure: Isotonic (0.9% NaCl) coupling; 0.9% NaCl (isotonic) solution was used as the coupling fluid during the ESWL procedure.
Experimental: Hypertonic Group; Patients in this group received extracorporeal shock wave lithotripsy (ESWL) using 3% NaCl (hypertonic) solution as the coupling fluid. (n=98)	Procedure: Hypertonic (3% NaCl) coupling; 3% NaCl (hypertonic) solution was used as the coupling fluid during the ESWL procedure.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Stone Fragmentation Success Rate	The percentage of patients achieving successful stone fragmentation, defined as residual fragments smaller than 4 mm.	2-4 weeks after the ESWL procedure
Post-ESWL Pain Scores	Pain intensity assessed using the Visual Analog Scale (VAS), where 0 represents no pain and 10 represents the worst imaginable pain.	Immediately after the ESWL procedure

Collaborators and Investigators

• Sponsor: Konya City Hospital
• Investigators: Principal Investigator: Ahmet Murat Bayraktar, MD, University of Health Sciences, Konya City Hospital, Department of Urology, Konya, Turkey

Study record dates

Study Major Dates

• Study Start (Actual): July 1, 2023
• Primary Completion (Actual): February 28, 2026
• Study Completion (Actual): February 28, 2026

Study Registration Dates

• First Submitted: May 7, 2026
• First Submitted That Met QC Criteria: May 7, 2026
• First Posted (Actual): May 13, 2026

Study Record Updates

• Last Update Posted (Actual): May 13, 2026
• Last Update Submitted That Met QC Criteria: May 7, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• 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; Public Health; Environment and Public Health; Socioeconomic Factors; Population Characteristics; Demography; Epidemiologic Measurements; Family Characteristics
• Other Study ID Numbers: 23/153

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: YES
• IPD Plan Description: De-identified individual participant data that underlie the results reported in the article, including demographic characteristics (age, sex), stone characteristics (size, location), pain scores (Visual Analog Scale), and stone fragmentation success rates.
• IPD Sharing Time Frame: The data will be available beginning 6 months and ending 36 months following article publication.
• IPD Sharing Access Criteria: Data will be shared with qualified researchers who provide a methodologically sound proposal to achieve the aims in the approved proposal. Proposals should be directed to the corresponding author's email. To gain access, data requestors will need to sign a data access agreement.
• IPD Sharing Supporting Information Type: STUDY_PROTOCOL; SAP

Drug and device information, study documents

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