Percutaneous nephrolithotomy for staghorn stones: Which nomogram can better predict postoperative outcomes?

Abstract

To identify independent predictors for postoperative stone-free status after percutaneous nephrolithotomy (PCNL) for staghorn stones and to compare Guy's, CROES and STONE nomograms regarding their predictive ability and accuracy specifically for staghorn stones. Data of 286 patients who underwent PCNL in our department were collected and analyzed. Several parameters, including the three nomograms, were analyzed to reveal independent predictors for postoperative stone-free status. The area under the curve was used to assess the predictive ability of the independent predictors. A total of 73 staghorn calculi were identified with mean stone burden of 1253.5mm(2). Mean Guy's, CROES and STONE score was 3.34, 125.8 and 9.95, respectively. Postoperative stone-free rate was 65.8%. In univariate analysis, all three nomograms were significantly associated with stone-free status. However, STONE was the only significant independent predictor in multivariate analysis. STONE also revealed the highest predictive accuracy compared to Guy's and CROES nomogram. STONE nephrolithometry was found to be the only predictor for stone-free rate after PCNL for staghorn stones compared to Guy's and CROES nomograms.