Kidney volume loss following percutaneous nephrolithotomy utilizing 3D planimetry

Parenchymal damage and renal function impairment following percutaneous nephrolithotomy (PCNL) are of great concern. This study aims to evaluate post-operative changes in renal volume after PCNL. We retrospectively analyzed baseline and post-PCNL CT images from 25 eligible patients from a single tertiary care center. All CT imaging was reviewed using 3D planimetry software (3D Splicer^®, Version 4.0). Segmentation was utilized to obtain total kidney volume (TKV), total kidney surface area, total stone surface area, and total stone volume. Wilcoxon signed-rank test was used for pair analysis, and univariate and multivariable analyses were performed to examine the relationships between clinical and planimetry data and renal volume loss. The median age of the cohort was 62 years, with the majority of the patients having undergone a previous PCNL (52.0%). The median TKV (cm³) pre- and post-PCNL were 225.25 and 178.09, respectively (p = 0.001), with average volume decline of 21%. While there was a statistically significant kidney volume loss in our cohort, there was no difference between pre- and post-operative serum creatinine (mg/dL): 0.93 and 0.94 (p = 0.696), respectively. Multivariable analysis showed a higher TKV loss with a larger kidney stone surface area (OR 1.002, CI 1-1.003, p = 0.035), while younger age was found to be protective (OR 0.791, CI 0.587-0.925 p = 0.028). Patients with previous history of PCNL experiences a more pronounced TKV loss (53.77 cm³, p = 0.031), as compared to PCNL naïve patients (13.05 cm³, p = 0.224). Our study consistently revealed a decrease in TKV following PCNL. Furthermore, among patients with larger stone surface areas, and history of previous PCNL there was an increase in the loss of TKV after the procedure.