To study the factors influencing the stone-free rate after percutaneous nephrolithotomy (PCNL) in kidney calculi.

Clinical data of 125 patients with nephrolithiasis underwent PCNL from May 2011 to May 2016 were retrospectively analyzed. Ultrasonic and KUB+IVU and computed tomography (CT) were used to evaluate the anatomy of the renal collecting system, area of calculus, degree of hydronephrosis, distribution of calculus, number of renal calculi and CT value of the calculi. Number of puncture channels, length of the puncture channel, size of the puncture channel, blood loss during operation and experience of the surgeon were recorded according to the operation records. Univariate analysis was performed for each factor. Factors found to be significantly different that were further analyzed using multivariate logistic regression analysis.

The stones of 92 cases were cleared, clearance rate was 73.6%. Univariate analysis showed that the following factors were associated with the stone-free rate: area of calculus, distribution of calculus, abnormal anatomy of the renal collecting system, number of renal calculi, length of the puncture channel, blood loss during operation, experience of the surgeon. Multivariate analysis showed that the following risk factors were independently associated with the stone-free rate: area of calculus, distribution of calculus, abnormal anatomy of the renal collecting system, number of kidney calculi. Surgeon's experience was a protective factor associated with the stone-free rate.

Abnormal anatomy of the renal collecting system, size of the calculi and distribution in the calyx were independent factors of the effect of PCNL and can be used to evaluate the effect of surgery. Surgeon's experience was beneficial to increasing the stone-free rate.

Kidney calculi; Percutaneous nephrolithotomy; Stone-free rate