PURPOSE: Imaging is routinely used for pre- and postoperative assessment of percutaneous nephrolithotomy (PCNL) patients.
We developed a nomogram for treatment success in PCNL.
PATIENTS AND METHODS: From November 2007 and December 2009, Clinical Research Office of Endourological Society (CROES) collected data from consecutive patients in 96 centers globally. Patients were evaluated for stone free status using plain abdominal radiography of kidney ureter and bladder (KUB). Treatment success was defined as no stones visible or residual fragments less than 4 mm. Multivariate regression was used to model relationship between preoperative descriptors and stone free rate. Variables included case load, prior treatment, BMI, stone burden, location and count, presence of staghorn and renal anomalies. Bootstrapping techniques were used for validation of the model. Adjusted Chi-square statistic (χ2) values were used to rank prognostic value of variables. A nomogram was developed using significant predictors from the model. Predictive accuracy of the nomogram was assessed using area under receiver-operating curve (AUC), and the nomogram was calibrated.
RESULTS: Stone burden was the most predictor of stone free rate (χ2= 30.27, P< 0.001). Other factors associated with stone free rate included case volume (χ2= 35.75, P< 0.001), prior stone treatment (χ2= 14.55, P< 0.012), presence of staghorn stone (adjusted χ2= 4.73, P< 0.029), stone location (χ2= 14.74, P< 0.001) and stone count (χ2= 4.78, P< 0.004). A nephrolithometric nomogram with a predictive accuracy (AUC=0.76) was developed.
CONCLUSION: Stone free rate in PCNL can be predicted using preclinical data and radiological information. We present a nephrolithometric nomogram for percutaneous nephrolithotomy.
Written by:
Smith A, Averch TD, Shahrour K, Opondo D, Daels FP, Labate G, Turna B, de la Rosette JJ. Are you the author?
Department of Urology, Long Island Jewish Medical Center, New Hyde Park, USA.
Reference: J Urol. 2013 Jan 22. pii: S0022-5347(13)00083-9.
doi: 10.1016/j.juro.2013.01.047
PubMed Abstract
PMID: 23353048
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