How practical is the application of percutaneous nephrolithotomy scoring systems? Prospective study comparing Guy’s Stone Score, S.T.O.N.E. score and the Clinical Research Office of the Endourological Society (CROES) nomogram

Abstract

ObjectiveTo prospectively compare the Guy’s Stone Score (GSS), S.T.O.N.E. [stone size (S), tract length (T), obstruction (O), number of involved calices (N), and essence or stone density (E)] score and the Clinical Research Office of the Endourological Society (CROES) nephrolithometric nomogram to predict percutaneous nephrolithotomy (PCNL) success rate and assess the correlation with perioperative complications.Patients and methodsWe prospectively evaluated all consecutive PCNL patients at our institute between 1 November 2013 and 31 May 2015. The above scoring systems were applied to preoperative non-contrast computed tomography and the practical difficulties in such applications were noted. Perioperative complications and the stone-free rate (SFR) were also recorded. Receiver operating characteristic curves were drawn and the areas under curves were compared and appropriate statistical analysis done.ResultsIn all, 48 renal units were included in the study. The overall SFR was 62.2%. The presence of staghorn stones (β = 27.285, 95% confidence interval 1.19–625.35; P = 0.039) was the only significant variable associated with the residual stones on multivariate analysis. Stone-free patients had significantly lower median GSS (2 vs 4) and S.T.O.N.E. scores (6 vs 10) and higher median CROES scores (83% vs 63%) (all P < 0.001) compared to residual-stone patients. All scoring systems were significantly associated with SFR (all P < 0.001). There was no significant difference in the areas under curves of the scoring systems (0.858, 0.923, and 0.931, respectively). Furthermore, all scoring systems had weak correlations with Clavien–Dindo classified complications (r = 0.29, P = 0.045; r = 0.40, P = 0.005 and r = −0.295, P = 0.04, respectively). We found no standardisation for the measurement of stone dimensions, tract length, Hounsfield units, and staghorn definition.ConclusionsAll scoring systems equally predicted SFR and had a weak correlation with Clavien–Dindo complications. Standardisation is needed for the variables in which they have been found deficient.

Comparison of STONE score, Guy’s stone score and Clinical Research Office of the Endourological Society (CROES) score as predictive tools for percutaneous nephrolithotomy outcome: a prospective study

“…In a large multicentre comparative study, Tailly et al [25] showed that all three scoring systems were equally predictive of post‐PCNL SFS. In a small prospective study cohort, Singla et al [26] performed a similar comparison and drew a similar conclusion. A extensive literature survey showed that Noureldin et al [27] favoured GSS and the STONE score for their significant associations with SFS, whereas Bozkurt et al [28] suggested that GSS and the CROES nomogram were significantly associated with SFS.…”

“…However, Vicentini et al [35] showed that GSS was associated with post‐PCNL complications. Singla et al [26] found weak correlation of modified Clavien–Dindo grades with the scoring systems.…”

Inter-observer variability amongst surgeons and radiologists in assessment of Guy’s Stone Score and S.T.O.N.E. nephrolithometry score: A prospective evaluation

“…scores correlated with complications, whereas Tailly et al [18] found that none of them correlated with complications. Tailly et al [18] also found that all three could predict residual fragments and were equivalent; this was also observed by Singla et al [26]. Both of these authors found S.T.O.N.E.…”

Assessment of lower calyceal single-access percutaneous nephrolithotomy for staghorn stones: A single-surgeon and a single-center experience at KAMC, Riyadh

“…This is higher than that reported by Singla et al ., Shalaby et al ., and Falahatkar et al . at 62.2%, 74.8%, and 76.2%, respectively,[181920] and lower than that reported by Tefekli et al ., 81.6%. [5] Two studies published in 2017 showed identical results regarding stone resolution rates (92%), which is significantly higher when compared to our result.…”