Impact of the “L” score from the RENAL nephrectomy score on RAPN surgical outcomes in medial versus lateral renal tumors

The significance of “L” score in the radius (R), exophytic/endophytic (E), nearness (N), anterior/posterior (A), location (L); RENAL nephrometry scoring system remains unestablished compared to other subscores. This study assessed the influence of the “L” score on surgical and functional outcomes of RAPN, dividing renal tumors into medial and lateral relative to the kidney's central line, to explore its impact on “L” score utility. A retrospective analysis was conducted on 668 RAPN patients, with 405 having medial and 263 lateral renal tumors. Patients who underwent RAPN were retrospectively analyzed, including 405 with medial renal tumors and 263 with lateral renal tumors. In medial tumors, the “L” score independently predicted non-achievement of trifecta (P = 0.013) and pentafecta (P = 0.008). In lateral tumors, the “L” score did not predict non-achievement of these outcomes. In conclusion, significance of the “L” score on surgical outcomes differs between medial and lateral tumors and it is strongly associated with outcomes in medial tumors, whereas its predictive value in lateral tumors is less marked. The RENAL score lacks differentiation between medial and lateral tumors; therefore, surgeons should interpret “L” scores with caution.