# Risk factors and prediction model for stone mucosa adhesion before retrograde intrarenal surgery

## TL;DR

This study identifies risk factors and develops a model to predict adhesions between kidney stones and the ureteral mucosa before surgery.

## Contribution

A novel predictive model for stone-mucosa adhesion using clinical factors like ureteral wall thickness and hydronephrosis severity.

## Key findings

- 48 out of 173 patients had confirmed adhesions between the calculus and the mucosa.
- Ureteral wall thickness, hydronephrosis severity, perirenal fat stranding, and pain intensity were independent risk factors for adhesions.
- The model showed excellent predictive performance with an area under the curve of 0.849 and 0.888 for groups with and without adhesions.

## Abstract

Preoperative assessment of ureteral adhesions related to stones is crucial for choosing the right surgical approach.

This study aimed to evaluate clinically significant factors for predicting the development of adhesions between the calculus and the mucosa in patients with ureteral stones undergoing retrograde intrarenal surgery.

The study included 173 patients. Ureteroscopy was performed to accurately identify the presence of adhesions between the calculus and the mucosa. Univariate and multivariable logistic regression analyses were performed to identify independent factors predicting adhesions. An alignment diagram model was developed utilizing the independent factors identified. Discrimination and calibration of the model were evaluated via the receiver operating characteristic curve and further examined via calibration curves, decision curve analysis, and cumulative intervention curves.

Adhesions between the calculus and the mucosa were confirmed on ureteroscopy in 48 patients (27.7%). Multivariable logistic regression analyses showed that ureteral wall thickness (UWT), hydronephrosis severity, perirenal fat stranding (PFS), and pain intensity were independent risk predictors of adhesions (P <⁠0.001; P <⁠0.001; P = 0.02; P = 0.02, respectively). The estimated area under the curve in the group with and without adhesions was 0.849 (95% CI, 0.742–0.832) and 0.888 (95% CI, 0.829–0.833), respectively, demonstrating an excellent predictive performance of the model.

UWT, PFS, hydronephrosis severity, and pain intensity are independent risk factors for the development of adhesions between the calculus and the mucosa. Our predictive model exhibited outstanding performance, and it may help clinicians choose the most appropriate surgical method.