Robot-assisted partial nephrectomy (RAPN) is a standard treatment for small renal cell carcinoma. The integration of virtual three-dimensional partial nephrectomy (3DvPN) images enhances surgical planning and intraoperative navigation. The Minimum Layer Resection (MLR) technique, guided by 3DvPN, enables precise tumor excision with minimal surgical margins, aiming to optimize both renal function preservation and oncological safety.

We retrospectively analyzed 312 patients who underwent RAPN between 2012 and 2022. Patients with less than three years of follow-up, prior renal embolization for arteriovenous malformation (AVM), radical nephrectomy, or contralateral renal surgery were excluded. The MLR technique utilized preoperative 3DvPN images to create a detailed surgical roadmap, allowing tumor resection with a 1–2 mm margin under direct vision. The primary endpoint was postoperative renal function, assessed by estimated glomerular filtration rate (eGFR) preservation at 2 weeks; 1, 3, and 6 months; and 1, 2, and 3 years. Secondary endpoints included factors associated with renal function outcomes and oncological safety.

At 3 months postoperatively, 91.0% of patients retained >90% of baseline eGFR, and 84.4% did so at 3 years. Short-term renal function (1 month) was significantly influenced by tumor size, warm ischemia time (WIT), blood loss, and application of MLR. Long-term function (3 years) was affected by tumor size, WIT, RENAL score, blood loss, and use of the MLR technique. Compared with conventional resection approaches, MLR was associated with superior renal function preservation. Notably, no increase in positive surgical margins or local recurrence was observed, supporting its oncological safety.

RAPN with 3DvPN-guided MLR enables precise tumor excision while preserving renal function both in the short and long term.This technique provides an effective balance between oncological control and functional outcomes, representing a promising advancement in nephron-sparing surgery.