The aim of our study was: a) to evaluate the usefulness of the MR model for renal pedicle exposure and identification of the tumor's exact location during LPN, and b) to evaluate the subjective utility of the MR model as an intraoperative reference tool.

Investigators prospectively enrolled 47 patients with LPN between June 2020 and February 2021. Patients were randomly assigned into two groups: the control group (24 patients), who underwent operation with an intraoperative ultrasound (US) control and the experimental group (23 patients), who underwent operation with the aid of the MR model. Randomization was performed using a computerized randomization program and sealed envelopes. Patients were included in the study if they were 18 years of age or older, were able to sign informed consent, and had T1a renal tumors amenable to LPN. Patients were excluded if they were unwilling to participate or did not meet the inclusion criteria. For each patient, investigators prospectively collected demographic data including age, body mass index, clinical tumor size, side, location, and complexity score according to the PADUA scoring system; perioperative data (including time for renal pedicle exposure and time for renal tumor detection and duration of ischemia); pathological data; data on postoperative functional outcome and complications, classified according to the Clavien-Dindo system.

Inclusion Criteria:

• able to sign informed consent
• had T1a renal tumors amenable to LPN

Exclusion Criteria:

• were unwilling to participate
• did not meet the inclusion criteria