# Can ureteric stone impaction be predicted preoperatively using noninvasive parameters? A prospective study

## TL;DR

This study investigates if noninvasive CT parameters and blood markers can predict if a ureteric stone will become impacted before surgery.

## Contribution

The study identifies ureteral wall thickness as a strong predictor of ureteric stone impaction using noninvasive CT data.

## Key findings

- Ureteral wall thickness (UWT) of 1.9 mm was a strong predictor of stone impaction with high specificity and accuracy.
- Stone location and hydronephrosis grade were also significant predictors of impaction.
- Acute phase markers like ESR and CRP were not associated with stone impaction.

## Abstract

To determine the potential predictive value of different non-contrast computed tomography (NCCT) parameters and acute phase markers (ESR and CRP) for identifying impacted ureteric stones preoperatively.

We included 70 patients with ureteric stones who underwent ureteroscope (URS) in this study. The NCCT parameters and acute phase reactants were measured and compared in the impacted and non-impacted stone groups using univariate and multivariate analysis.

Out of the 70 patients, 35 had impacted ureteric stones. Using univariate analysis, we found that stone volume, stone location, hydronephrosis grade, and ureteral wall thickness (UWT) were the variables affecting the impaction, while by multivariate analysis, no significant association was detected between impaction and stone volume (p = 0.42). No association was found between the acute phase reactants and prediction of stone impaction Based on the receiver operating characteristic (ROC) curve analysis, UWT cutoff of 1.9 mm is an excellent predictor of impaction with 72.2% sensitivity, 94.1% specificity, and an overall accuracy level of 82.9%.

Stone location, hydronephrosis grade and UWT were the best predictors for ureteric stone impaction preoperatively.