Preoperational factors affecting the stone-free rate after percutaneous nephrolithotripsy
Shao Zhiqiang1,Yang Yong1,Yang Yu1,Lin Maohu1 Wang Guangjian2,Zhu Wenbin2,Guo Fengfu2
1Department of Urology, the First Affiliated Hospital of the General Hospital of PLA, Beijing 100048, China; 2Department of Urology, Linyi People's Hospital, Shandong Province
Abstract：Objective: Percutaneous nephrolithotripsy (PCNL) is the treatment choice for patients with extensive stone burden or stones refractory to extracorporeal shock wave lithotripsy. However, little is known about factors predicting unfavorably outcome in terms of stone-free rate. This study was performed to investigate the preoperational factors associated with the stone-free rate of PCNL for complex kidney stones. Methods: Between January 2012 and December 2013, a total of 642 patients (393 men and 249 women; age range 19-74 years; mean age 41 years) with complex kidney stones were treated by PCNL with pneumatic and ultrasonic power under B-type ultrasound guidance. All cases were identified by KUB/IVU, type B ultrasonic and computed tomography. Patients' age, sex, height, weight, body mass index (BMI), duration of disease, stone burden, number, side, location, pre-existent urinary tract infection, hydronephrosis and previous kidney surgery were evaluated before PCNL, and treatment efficacies were evaluated at 3-5 days after operation. Treatment success was correlated with stone features and patient characteristics using the chi square test and t-test. Factors found to be significant using the tests were further analyzed using multivariate regression analysis. Results: Using the chi square test and t-test, BMI, stone burden, number and location had significant impacts on the stone-free rate (P<0.05). Multivariate analysis excluded BMI and stone number from the logistic regression model, while the stone burden and stone location maintained statistically significant effect on success rate, indicating that there is independent predictor. Conclusions: This study demonstrated that stone burden and stone location were significant predictors of PCNL outcome, suggesting that large stone of mixed location is associated with low stone-free rate.
[1]Opondo D, Gravas S, Joyce A, et al. Standardization of patient outcomes reporting in percutaneous nephrolithotomy. J Endourol, 2014,28(7):767-774. [2]Bagrodia A, Gupta A, Raman JD, et al. Predictors of cost and clinical outcomes of percutaneous nephrostolithotomy. J Urol, 2009,182(2): 586-590. [3]Knox ML, Cantor AM, Bryant JE, et al. Predictive factors for percutaneous nephrolithotomy outcomes in neurogenic bladder population. J Endourol, 2012,26(7): 823-827. [4]Pérez-Fentes DA, Gude F, Blanco M, et al. Predictive analysis of factors associated with percutaneous stone surgery outcomes. Can J Urol, 2013,20(6):7050-7059. [5]Smith A, Averch TD, Shahrour K, et al. Nephrolithometric nomogram to predict treatment success of percutaneous nephrolithotomy. J Urol, 2013,190(1):149-156. [6]Shahrour K, Tomaszewski J, Ortiz T, et al. Predictors of immediate postoperative outcome of single-tract percutaneous nephrolithotomy. Urology, 2012,80(1): 19-25. [7]王洛夫,葛成国,万江华,等.微创经皮肾镜取石术后结石残留的原因分析.重庆医学,2009,17 (38):2159-2160. [8]Bagrodia A, Gupta A, Raman JD, et al. Impact of body mass index on cost and clinical outcomes after percutaneous nephrostolithotomy. Urology, 2008, 72(4): 756-760. [9]Alyami FA, Skinner TA, Norman RW. Impact of body mass index on clinical outcomes associated with percutaneous nephrolithotomy. Can Urol Assoc J, 2012,15:1-5. [10]Gonulalan U, Akand M, Coban G, et al. Skin-to-stone distance has no impact on outcomes of percutaneous nephrolithotomy. Urol Int, 2014,92(4):444-448. [11]Anastasiadis A, Onal B, Modi P, et al. Impact of stone density on outcomes in percutaneous nephrolithotomy (PCNL): an analysis of the clinical research office of the endourological society (CROES) pcnl global study database. Scand J Urol, 2013,47(6):509-514. [12]Al-Tawheed AR, Al-Awadi KA, Kehinde EO, et al. Treatment of calculi in kidneys with congenital anomalies: an assessment of the efficacy of lithotripsy. Urol Res, 2006,34(5):291-298. [13]Miller NL, Matlaga BR, Handa SE, et al. The presence of horseshoe kidney does not affect the outcome of percutaneous nephrolithotomy. J Endourol, 2008,22(6): 1219-1225. [14]Yaycioglu O, Egilmez T, Gul U, et al. Percutaneous nephrolithotomy in patients with normal versus impaired renal function. Urol Res, 2007,35(2):101-105. [15]Karami H, Mazloomfard MM, Golshan A. Does age affect outcomes of percutaneous nephrolithotomy? Urol J, 2010,7(1):17-21. [16]Resorlu B, Kara C, Senocak C, et al. Effect of previous open renal surgery and failed extracorporeal shockwave lithotripsy on the performance and outcomes of percutaneous nephrolithotomy. J Endourol, 2010,24(1):13-16.
