Abstract
OBJECTIVE: To assess long-term changes in renal volume and function after laparoscopic partial nephrectomy using 3D modeling and to identify key predictors. PATIENTS AND METHODS: This retrospective study included 187 patients who underwent laparoscopic partial nephrectomy between October 2012 and January 2023. Patients underwent the same cross-sectional imaging both pre- and postoperatively, with a minimum follow-up of one year. Pre- and postoperative volumes were reconstructed with 3D Slicer software. RESULTS: The median age of the patients was 58 years. The median Radius-Exophytic-Nearness-Anterior-Location (RENAL) score was 7. The median tumor volume was 15.8 cm³. The median warm ischemia time was 14 minutes, and the median surgical time was 80 minutes. The mean tumor-free renal parenchymal volume before surgery was 168,87 ± 40,91 cm³, which decreased to a mean operated renal parenchymal volume of 137.6 ± 41.7 cm³ at 5 years postoperatively. The estimated glomerular filtration rate (eGFR) declined from a median value of 90.6 to 75.9 mL/min/1.73 m² over the same period. The predictors of renal function decline were parenchymal volume loss, age, female gender, diabetes mellitus, and tumor-to-parenchyma contact surface area. Factors affecting parenchymal volume loss included age, RENAL score, comorbidities, Surface-Intermediate-Base (SIB) score, and operative time. CONCLUSIONS: While the most influential factor on renal function in the early postoperative period was the preserved renal volume, diabetes mellitus (DM) emerged as the primary determinant of long-term functional outcomes. Tumor resection technique and operative time are modifiable factors influencing parenchymal volume preservation. Enucleation-based approaches may enhance parenchymal preservation without compromising oncological outcomes.