3D-CT vs Ellipsoid for JJ Stent Prediction Before ESWL

NCT ID: NCT07337954

Last Updated: 2026-01-13

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 56 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-01-01
• Study Completion Date: 2024-06-30

Brief Summary

This prospective single-center study compares 3D-CT volumetry versus traditional ellipsoid formula to determine critical stone burden predicting JJ stent necessity before ESWL for 1-2 cm renal stones. Fifty-six patients with single radio-opaque renal stones will receive up to two ESWL sessions using Dornier lithotripter without initial stenting. Stone characteristics will be assessed via NCCT: linear dimensions (ellipsoid formula), 3D volume (voxel-based segmentation), Hounsfield units, and skin-to-stone distance. Patients will be stratified by ESWL outcomes to compare volume measurements between clearance success and stent-requiring groups..

Detailed Description

This prospective single-center study at Ain Shams University evaluates 3D-CT volumetry versus traditional ellipsoid formula for predicting critical stone burden requiring preoperative JJ stent placement in patients undergoing ESWL for 1-2 cm renal stones. Eligible patients (target n=56) with single radio-opaque renal stones will receive two ESWL sessions using Dornier lithotripter without initial stenting. Stone characteristics will be assessed via non-contrast CT (NCCT): linear dimensions (ellipsoid formula: length×width×height×0.52), 3D volume (automated voxel-based segmentation), Hounsfield units, and skin-to-stone distance.

Patients will be stratified by ESWL outcomes: stone clearance without stenting versus those requiring JJ stent due to complications (infection, incomplete fragmentation, obstruction/Stein Strasse). Volume measurements will be compared between groups using appropriate statistical tests (t-test, ROC analysis). The study aims to establish a 3D-CT volume threshold for stent prediction and validate its superiority over ellipsoid formula, particularly for irregular stone morphology.

Conditions

Urolithiasis; Shock Wave Lithotripsy; Ureteral Stents

Study Design

• Allocation Method: NA
• Intervention Model: SINGLE_GROUP
• Primary Study Purpose: DIAGNOSTIC
• Blinding Strategy: NONE

Study Groups

ESWL without Initial JJ Stent

All 56 patients received standardized ESWL treatment using third-generation Dornier lithotripter (maximum 2 sessions, 2500 shock waves/session). No preoperative JJ stent placement. Stone volume assessed via dual methods: 3D-CT volumetry (voxel-based segmentation) and ellipsoid formula (greatest dimensions on NCCT). Follow-up at 2 weeks with KUB/ultrasound; JJ stent placed for complications (incomplete fragmentation, obstruction, Stein Strasse, infection)

Group Type: EXPERIMENTAL

Extracorporeal shock wave lithotripter

Intervention Type: DEVICE

ESWL delivered at 70-80 shocks/min, max 2500 shocks/session, voltage ramped to 90 kV. Stone localization via fluoroscopy.

Interventions

Extracorporeal shock wave lithotripter

ESWL delivered at 70-80 shocks/min, max 2500 shocks/session, voltage ramped to 90 kV. Stone localization via fluoroscopy.

Intervention Type: DEVICE

Eligibility Criteria

Inclusion Criteria

• Age 18-65 years
• BMI 18-30 kg/m²
• Single radio-opaque renal stone 1-2 cm
• Suitable for ESWL per clinical assessment

Exclusion Criteria

• Multiple renal stones
• Solitary kidney
• Impaired renal function
• Congenital renal anomalies
• Ureteric obstruction
• Systemic comorbidities
• Pregnancy

• Minimum Eligible Age: 18 Years
• Maximum Eligible Age: 65 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Ain Shams University

OTHER

Sponsor Role: lead

Responsible Party

Hossam Elawady

Principal Investigator

Responsibility Role: PRINCIPAL_INVESTIGATOR

Locations

Faculty of Medicine, Ain Shams University

Cairo, Cairo Governorate, Egypt

Countries

Egypt

Other Identifiers

FMASU MS872024

Identifier Type: -

Identifier Source: org_study_id