The ‘upside-down’ technique in transperitoneal robotic partial nephrectomy: visual standardization and clinical outcomes in 50 consecutive dorsally located renal masses

An ideal partial nephrectomy (PN) should achieve optimal perioperative, functional, and oncological outcomes. We adapted a robotic-assisted transperitoneal technique for the management of dorsally positioned renal masses across all tumor locations. Drawing inspiration from kidney transplantation surgery, we have termed this technique the “upside-down” PN. This single-center retrospective cohort study included 50 consecutive patients with dorsally located renal tumors who underwent robotic-assisted PN using the “upside-down” transperitoneal approach. Tumor complexity was assessed using the PADUA score. Trifecta outcomes were evaluated and compared across tumor complexity and tumor locations. The cohort was dominated by high-complexity tumors, with 44% exhibiting a PADUA score ≥ 10, and 35.3% of malignant tumors classified as pT1b grade postoperative. Mean operative time was 148.6 ± 29.3 min, with a mean console time of 69.7 ± 6.9 min, without significant differences among PADUA complexity groups. Negative surgical margins (R0) were achieved in all cases (100%). Overall, Trifecta outcomes were achieved in 78% of patients and in 61% of those with a hilar tumor. A PADUA score ≥ 10 was significantly associated with reduced Trifecta outcome, although Trifecta was still achieved in 59.1% of cases. Hilar tumors and larger tumor size were significantly associated with lower Trifecta rates. The “upside-down” transperitoneal technique for robotic-assisted PN provides satisfactory perioperative, functional, and oncological outcomes for dorsally positioned renal masses, including complex and hilar tumors. Despite limitations related to its single-center design and sample size, this study offers a visually reproducible workflow of the technique, providing a structured guide for centers managing complex dorsal renal tumors via a transperitoneal approach.