Early changes in renal parenchymal stiffness after partial nephrectomy assessed by shear wave elastography

To evaluate whether SWE could be used to assess the renal parenchyma in patients undergoing PN for RCC. This prospective single-center study included 36 adult patients who underwent PN due to RCC. SWE values, resistive index (RI), estimated glomerular filtration rate (eGFR), serum creatinine, and urea were measured preoperatively and on postoperative days 1 and 7. Univariate and multivariable linear regression analyses were performed to identify independent predictors of the SWE value on postoperative day 7. SWE measurements declined from a preoperative mean of 22.78 ± 11.98 kPa to 18.84 ± 8.24 kPa on postoperative day 1 and partially recovered to 20.51 ± 9.42 kPa by day 7 ( p = 0.091). During this period, eGFR decreased ( p = 0.010) and serum creatinine increased ( p < 0.001). In multivariable analysis, medial tumor location (B = 7.541, 95% CI: 2.692–12.390, p = 0.003) and preoperative SWE (B = 0.336, 95% CI: 0.132–0.540, p = 0.002) were independently associated with postoperative day-7 SWE. In a sensitivity analysis of change from baseline, medial location was not significant ( p = 0.446), whereas preoperative SWE, ischemia duration, diabetes mellitus, right-sided laterality, and tumor size were significant predictors. Renal parenchymal stiffness showed a non-significant, transient fluctuation after partial nephrectomy, whereas conventional functional markers showed significant early impairment. A sensitivity analysis suggested that the association between tumor location and postoperative stiffness was influenced by baseline differences, while ischemia duration and tumor size may better reflect surgery-related parenchymal change. These preliminary findings require confirmation in larger cohorts with longer follow-up before SWE can be considered a validated monitoring tool in this setting.