Presentation Authors: David Bayne*, Manuel Armas-Phan, Scott Wiener, SAN FRANCISCO, CA, Weiguo Hu, Bo Xiao, Boxing Su, Wenjie Bai, Bejing, China, People's Republic of, Marshall Stoller, Tom Chi, SAN FRANCISCO, CA, Jianxing Li, Bejing, China, People's Republic of
Introduction: AUA guidelines recommend shockwave lithotripsy (SWL) or ureteroscopy (URS) for symptomatic lower pole renal stones < 10mm and non-lower pole renal stones < 20mm. We hypothesize that percutaneous nephrolithotomy (PCNL) can be performed safely in patients with stones < 10mm with minimal risk of complication and higher stone free rate compared to URS or SWL. Using an international stone registry we investigated the stone free and complication rates after PCNL for stones < 10mm relative to URS and/or SWL, and to determine international practice pattern differences in PCNL utilization.
Methods: Prospectively collected international data from the Registry for Stones of the Kidney and Ureter (ReSKU) composed of patients from the United States and China between September 2015 to July 2018 were investigated to evaluate characteristics of surgical patients treated for stones < 10mm. Data on patient age, gender, BMI, stone location, delay to surgery, complication and transfusion rates, and stone clearance efficiency were analyzed. Univariate analysis was performed using Fisher&[prime]s Exact test and Welch Two Sample t-test. Multivariate analysis was performed using logistic regression. Statistical analysis was performed in R version 3.3.3.
Results: A total of 2329 surgical stone procedures were undertaken; 303 procedures for stones < 10mm were identified. Multivariate analysis revealed that older age (p=0.028, OR 0.97 per year) was associated with lower likelihood of PCNL for stones < 10mm. Surgery performed in China was associated with higher rate of PCNL for stones < 10mm (p=0.002, OR 5.26). There were no differences in complication or transfusion rates. Stone clearance was higher in patients undergoing PCNL (93% vs 82%; p=0.103) but this was not statistically significant.
Conclusions: When controlling for other variables, PCNL for stones < 10mm is more commonly performed in younger patients and in China. There is no difference in complications or transfusion rates when comparing patients undergoing PCNL versus URS or SWL. International differences in surgical practice patterns may be explained by availability and comfort performing flexible ureteroscopy. In centers with a high volume of PCNL procedures, using this approach for small stones can be performed safely with no difference in complication rates relative to other procedures.
Source of Funding: NIH grant P20-DK-116193