Preoperative superselective transarterial ICG-lipiodol embolization for endophytic renal tumors in robot-assisted partial nephrectomy: a preliminary feasibility report

Partial nephrectomy for small, anatomically complex renal tumors presents significant navigational challenges. This study aims to evaluate the synergistic hemostatic and navigational utility and surgical outcomes of preoperative superselective indocyanine green (ICG) embolization during retroperitoneal robot-assisted partial nephrectomy (RAPN). We retrospectively reviewed 32 patients who underwent retroperitoneal RAPN for small renal masses (< 4 cm). Patients were stratified by preoperative intervention: 9 patients (28.1%) received superselective transarterial delivery of an ICG-lipiodol mixture with coil embolization 3 h prior to surgery, while 23 patients (71.9%) underwent standard RAPN. A uniform main renal artery clamping protocol was maintained across both cohorts to evaluating the combined utility of ICG. Strikingly, the ICG cohort consisted entirely of completely endophytic tumors (E3 component: 100% vs. 13%, p < 0.001). Despite this extreme anatomical complexity, the ICG group demonstrated significantly shorter median operative time (90.0 vs. 100.2 min, p = 0.049) and lower median estimated blood loss (100 vs. 350 mL, p = 0.039). Consequently, the perioperative blood transfusion rate was lower in the ICG group (11.1% vs. 60.9%, p = 0.018). Median warm ischemia time (16.48 vs. 16.78 min, p = 0.900) and postoperative renal function changes at day 1, 6 months, and 1 year were comparable between groups. No gastrointestinal or embolization-related complications were observed. Our preliminary experience demonstrates that preoperative superselective ICG embolization serves as a feasible and safe adjunct during RAPN for completely endophytic tumors. By providing a synergistic combination of direct local hemostasis and real-time fluorescent navigation, this tailored approach facilitates precise tumor localization. While these initial findings suggest potential perioperative advantages, they should be interpreted as exploratory signals awaiting further validation in larger, well-balanced cohorts.