A prospective comparative evaluation of preoperative stone scoring systems with respect to stone free rate and complications in percutaneous nephrolithotomy

Abstract

Background:

PCNL outcomes among urologists are different because of the vast heterogeneity in the methods for clinical, academic characterisation and evaluation of surgical outcomes of nephrolithiasis. So assessing the preoperative factors that affect SFR (Stone Free Rate) and complications is critical. Heterogeneity in reporting of PCNL outcomes among different centres has led to the invention of nephrolithotomy scoring systems based on preoperative parameters to better counsel patients contemplating PCNL. The Guy’s stone score, CROES nomogram and the S.T.O.N.E score are seen as predictors of stone-free status (SFS) and complications after PCNL. No universally accepted stone scoring system for predicting SFR and complications after PCNL exists. This is a prospective observational study to compare and analyse the existing stone scoring systems (SSS) and to assess the best parameters to predict PCNL outcomes concerning SFR and complications.

Methods:

This study is done in a tertiary level institute in eastern India which included 200 patients who underwent PCNL from November 2019 to November 2021. The relevant operative parameters were documented and compared to the preoperative factors with the help of nephrolithotomy scoring systems.

Results:

The Guy score, CROES nomogram and S.T.O.N.E. score were accurate in predicting the SFR in patients undergoing PCNL. A new IPGMER preoperative stone scoring system based on the most relevant parameters could be used as an alternative to predict SFR and complications in PCNL.

Conclusion:

The Nephrolithometry scoring systems are simple, straightforward and easily reproducible systems to classify the severity of nephrolithiasis and to stratify the complexity of PCNL.