Utilidad de la escala S.T.O.N.E. como herramienta de predicción terapéutica en cirugía intrarrenal retrógrada

Background

Retrograde intrarenal surgery (RIS) for the treatment of kidney stones has increased in the last few years. The S.T.O.N.E. score has been described as a reproducible tomographic evaluation tool enabling the complexity of urinary calculi to be estimated, thus establishing predictive factors for therapeutic success.

Aim

To determine the factors that influence the success of RIS in the treatment of kidney stones in 95 patients at a tertiary care hospital in Mexico City, in relation to the S.T.O.N.E. score calculation and the value of each of the stone variables in the corresponding preoperative tomographic study.

Material and methods

In a sample of 95 patients, those that were stone-free and those that presented with residual stones after a single RIS event were identified. The S.T.O.N.E. score was calculated through a preoperative tomographic evaluation. The correlation between the S.T.O.N.E. score and residual stone status was identified through the Pearson test and the individual impact of each of the stone variables was determined through the logistic regression test.

Results

A total of 64 patients were stone-free and 31 patients presented with significant lithiasis. Analysis of the logistic regression test revealed stone size (P = .0127), number (P = .0400), and density (P = .0079) as predictive factors for stone-free status.

Conclusions

The preoperative evaluation with the S.T.O.N.E. score is a predictive tool for RIS therapeutic success. Identification of the variables having greater therapeutic impact will enable better patient selection for RIS as surgical treatment.