Factors Affecting Preserved Renal Volume and Function After Laparoscopic Partial Ne-phrectomy: A Long-Term 3D...

To assess long-term changes in renal volume and function after laparoscopic partial nephrectomy using 3D modeling and to identify key predictors.

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.

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.

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.