Functional and volumetric changes following partial nephrectomy for large (≥7 cm) renal masses: A comparative study

Purpose: Partial nephrectomy (PN) has been performed for renal masses ≥7cm with promised oncological outcome, whereas their functional and volumetric changes remain unclear. To evaluate renal functional and volumetric changes after PN for renal masses ≥7cm and compare with smaller renal masses(<7cm). Methods: A total of 107 patients with renal masses ≥7 cm who underwent PN with sufficient data were included. PN patients with renal masses <7 cm were included as control. Spectrum score, recovery from ischemia and annual ipsilateral renal parenchymal volume (RPV) decrease was used to reflect short, mid, and long-term functional/volumetric changes, respectively. Propensity score matching (1:1) minimized baseline bias. Result: The median tumor size was 8cm(IQR: 7.5-9cm) with a median R.E.A.N.L. score of 10(IQR: 8-10) and the median ischemia time was 30 minutes, which were all significantly greater than control group. Although the study group demonstrated lower ipsilateral renal volume(81.5% vs. 88.3%) and GFR preservation(74.6% vs. 84.4%, both p < 0.001), spectrum sore(0.25 vs. 0.21, p=0.2), recovery from ischemia(91.6% vs. 93.8%, p=0.2) and annual ipsilateral RPV decrease(5.5% vs. 3.4%, p=0.3) were comparable between the study and control group. These findings remained consistent after PSM. Limitations include small sample size with limited follow-up. Conclusions: Compared to smaller renal masses(<7 cm), PN for masses ≥7 cm was associated with moderately reduced ipsilateral renal volume and GFR preservation. However, AKI severity, mid-term functional recovery, and long-term volumetric changes were not compromised, supporting the feasibility of PN for large renal masses.