# Indocyanine-Green-Guided Partial Nephrectomy: A Narrative Review Addressing Protocol Heterogeneity, Perioperative Functional and Oncological Outcomes

## TL;DR

This review examines how using indocyanine green with near-infrared imaging during kidney surgery helps surgeons but lacks long-term benefits due to inconsistent protocols.

## Contribution

The paper proposes minimum criteria for standardizing indocyanine green use in kidney surgery to improve reproducibility and outcomes.

## Key findings

- ICG-NIRF improves real-time perfusion visualization and tumor-parenchyma contrast in some cases.
- Small reductions in warm ischemia time and modest short-term eGFR improvements are reported.
- No consistent long-term functional or oncologic benefits are demonstrated due to protocol variability.

## Abstract

Background and Objectives: Partial nephrectomy is the preferred intervention for many localized renal tumors; but intraoperative tumor localization, real-time perfusion evaluation, and vascular control optimization can be technically demanding, especially in endophytic or complex lesions. Near-infrared fluorescence (NIRF) imaging with indocyanine green (ICG) has been adopted as an intraoperative adjunct to improve visualization, support selective or super-selective clamping strategies and assist tumor to parenchyma contrast and selective vascular control. However, current evidence regarding the benefit of ICG-NIRF is often inconsistent, and a significant gap exists due to the lack of standardized intraoperative protocols, which limits the reproducibility of clinical results. This review aims to synthesize existing comparative evidence, identify the sources of methodological heterogeneity, and propose minimum criteria for the standardization of ICG use in renal surgery. Materials and Methods: A narrative review was conducted using PubMed with the terms near-infrared fluorescence, indocyanine green, and partial nephrectomy, focusing on comparative clinical studies published since 2012. Key endpoints included warm ischemia time (WIT), positive surgical margins (PSMs), perioperative outcomes, short-term renal functional measures (eGFR and or split renal function), and available oncologic follow-up. Results: ICG-NIRF enables real-time visualization of renal perfusion and vascular anatomy and may improve tumor parenchyma contrast in superficial or partially exophytic tumors, facilitating selective clamping in selected cases. Comparative cohorts and meta-analyses report small reductions in WIT (approximately 1 to 3 min) in some series, modest short-term superiority in eGFR (e.g., 4.62 mL/min at discharge or 9.26 mL/min at 1 to 3 months), no consistent differences in PSM rates (reported ranges of 0 to 11 percent across studies), major complications, or recurrence outcomes. Durable improvements in long-term renal function and consistent benefits in split renal function have not been demonstrated. Interpretation is limited by heterogeneity in ICG dosing, timing, imaging platforms, and acquisition. Conclusions: ICG-NIRF is a useful adjunct for intraoperative perfusion assessment and selective vascular control during partial nephrectomy, but current evidence does not demonstrate long-term functional or oncologic benefit over standard approaches. Further progress requires protocol standardization, quantitative fluorescence metrics, and adequately powered trials with long-term functional and oncologic endpoints, together with the development of deeper-penetrating and more tumor-specific fluorophores.