NCT07337954

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

Estimation of Critical Stone Burden Requiring JJ Stent Before Extracorporeal Shockwave Lithotripsy Using 3D-CT

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 56 (actual)
• Sponsor: Ain Shams University · Academic / Other
• Sex: All
• Age: 18 Years – 65 Years
• Healthy volunteers: Not accepted

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

Interventions

Type	Name	Description
DEVICE	Extracorporeal shock wave lithotripter	ESWL delivered at 70-80 shocks/min, max 2500 shocks/session, voltage ramped to 90 kV. Stone localization via fluoroscopy.

Timeline

• Start date: 2024-01-01
• Primary completion: 2024-06-30
• Completion: 2024-06-30
• First posted: 2026-01-13
• Last updated: 2026-01-13

Locations

1 site across 1 country: Egypt