Iqbal N, Hasan A, Iqbal S, Noureen S, Akhter S. Role of variation coefficient of stone density in determining success of shock wave lithotripsy in urinary calculi. World J Nephrol 2025; 14(1): 96946 [DOI: 10.5527/wjn.v14.i1.96946]
Corresponding Author of This Article
Nadeem Iqbal, FCPS, Surgeon, Department of Urology and Kidney Transplant, Shifa Intl Hospitals, House 305, Railways Colony, Transit Chowk, Islamabad 44790, Pakistan. dr_nadeemiqbal84@yahoo.com
Research Domain of This Article
Urology & Nephrology
Article-Type of This Article
Observational Study
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Nadeem Iqbal, Department of Urology and Kidney Transplant, Shifa Intl Hospitals, Islamabad 44790, Pakistan
Nadeem Iqbal, Department of Urology, Pakistan Kidney and Liver Institute, Lahore 54000, Punjab, Pakistan
Aisha Hasan, Department of Biochemistry, Riphah International University, Rawalpindi 44000, Punjab, Pakistan
Sajid Iqbal, Department of Rehabilitation, PNS Karachi, Karachi 75950, Sindh, Pakistan
Sadaf Noureen, Department of Medicine, Groves Medical Center, New Malden, London KT3 3PB, United Kingdom
Saeed Akhter, Department Urology, Shifa International Hospital Islamabad, Islamabad 44000, Pakistan
Author contributions: Iqbal N conceived the idea, designed the study, collected the data, performed statistical analysis & manuscript writing manuscript and editing, and is responsible for the integrity of research; Hasan A, Iqbal S, and Noureen S were responsible for data collection, statistical analysis, and manuscript writing; Iqbal S was responsible for manuscript proofreading; Akhter S conceived the idea, designed the study, performed statistical analysis & manuscript editing, and is responsible for the integrity of research.
Institutional review board statement: This study was approved by the local Institutional Review Board.
Informed consent statement: All patients provided informed consent before the SWL procedure.
Conflict-of-interest statement: The authors have nothing to disclose for this article.
Data sharing statement: No additional data are available.
STROBE statement: The authors have read the STROBE Statement—checklist of items, and the manuscript was prepared and revised according to the STROBE Statement—checklist of items.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: https://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Nadeem Iqbal, FCPS, Surgeon, Department of Urology and Kidney Transplant, Shifa Intl Hospitals, House 305, Railways Colony, Transit Chowk, Islamabad 44790, Pakistan. dr_nadeemiqbal84@yahoo.com
Received: May 18, 2024 Revised: August 10, 2024 Accepted: September 3, 2024 Published online: March 25, 2025 Processing time: 246 Days and 14.5 Hours
Abstract
BACKGROUND
Various stone factors can affect the net results of shock wave lithotripsy (SWL). Recently a new factor called variation coefficient of stone density (VCSD) is being considered to have an impact on stone free rates.
AIM
To assess the role of VCSD in determining success of SWL in urinary calculi.
METHODS
Charts review was utilized for collection of data variables. The patients were subjected to SWL, using an electromagnetic lithotripter. Mean stone density (MSD), stone heterogeneity index (SHI), and VCSD were calculated by generating regions of interest on computed tomography (CT) images. Role of these factors were determined by applying the relevant statistical tests for continuous and categorical variables and a P value of < 0.05 was gauged to be statistically significant.
RESULTS
There were a total of 407 patients included in the analysis. The mean age of the subjects in this study was 38.89 ± 14.61 years. In total, 165 out of the 407 patients could not achieve stone free status. The successful group had a significantly lower stone volume as compared to the unsuccessful group (P < 0.0001). Skin to stone distance was not dissimilar among the two groups (P = 0.47). MSD was significantly lower in the successful group (P < 0.0001). SHI and VCSD were both significantly higher in the successful group (P < 0.0001).
CONCLUSION
VCSD, a useful CT based parameter, can be utilized to gauge stone fragility and hence the prediction of SWL outcomes.
Core Tip: In the recent literature various computed tomography (CT) based stone parameters have been studied regarding their role in success of shock wave lithotripsy. These non-contrast CT parameters include skin-stone distance, stone volume, and stone density, which might help in prediction of the success of shock wave lithotripsy (SWL). In recent guidelines, it has been agreed upon that successful outcomes become less likely for harder stones-stone density more than 900-1000 Hounsfield units. Recently, novel parameters such as stone heterogeneity index and variation coefficient of stone density can be representative of stone heterogeneity and can be of utility in prediction of SWL outcome. We, in this study, tried to ascertain their predictive role in shock wave lithotripsy outcomes.
