“Ride the Green Light”: Indocyanine Green–marked Off-clamp Robotic Partial Nephrectomy for Totally Endophytic Renal Masses

Background: Complexity of robot-assisted partial nephrectomy (RAPN) mostly depends on tumor size and location. Totally endophytic renal masses represent a surgical challenge in terms of both intraoperative identification and anatomical dissection. Objective: To detail a novel technique for marking preoperatively endophytic renal tumors with transarterial superselective intrarenal mass delivery of indocyanine green (ICG)-lipiodol mixture, in order to enhance surgical margins control during purely off-clamp (OC) RAPN with the use of near-infrared fluorescence imaging. Design, setting, and participants: Between June and July 2017, 10 consecutive patients with totally endophytic renal masses underwent preoperative ICG tumor marking immediately followed by RAPN. Surgical procedure: Preoperative superselective transarterial delivery of a lipiodol-ICG mixture (1:2 volume ratio) into tertiary-order arterial branches feeding the renal mass prior to transperitoneal OC-RAPN. Measurements: Clinical data were prospectively collected in our institutional RAPN dataset. Perioperative, pathological, and functional outcomes of RAPN were assessed. Results and limitations: Median tumor size was 3 cm (interquartile range 2.3–3.8). The median PADUA score was 10 (9–11). Angiographic procedure was successful in all patients. Median operative time was 75 min (65–85); median estimated blood loss was 250 ml (200–350). No conversion to on-clamp PN or radical nephrectomy was needed. All patients had uneventful perioperative course; median hospital stay was 3 d (2–3). At discharge, median hemoglobin (Hgb) and percent estimated glomerular filtration rate (eGFR) drop were 3.3 g/dl (2.1–3.3) and 11% (10–20%), respectively. Surgical margins were negative in all cases. One-year median ipsilateral renal volume and 1-yr eGFR percent decreases were 11.7% (6–20.9%) and 12.2% (5.3–13.7%), respectively. Conclusions: We described a novel technique to simplify challenging RAPN based on ICG superselective transarterial tumor marking. Key benefits include quick intraoperative identification of the mass with improved visualization and real-time control of resection margins. Patient summary: Robot-assisted partial nephrectomy (RAPN) for totally endophytic renal masses is a technically demanding surgical procedure, sometimes requiring radical nephrectomy. This novel technique significantly simplified surgical complexity in our Institution. Further studies with larger cohorts are warranted to confirm whether this technique provides relevant intraoperative and functional advantages. According to our preliminary experience, off-clamp robot-assisted partial nephrectomy after preoperative superselective indocyanine green tumor marking appeared to be a safe and effective procedure for the surgical treatment of totally endophytic renal tumors, achieving full trifecta outcomes and excellent functional results. Further prospective studies are awaited