Indocyanine green fluorescence-guided surgery in acute settings: state-of-the art.

Background: Operating in acute surgical settings is significantly different from elective surgery. One aspect is the complexity of acutely ill or injured patients with abnormal physiology, unoptimized comorbidities, and unplanned interventions. Traditional visual and tactile assessments of the surgical field anatomy and tissue viability have documented limitations. The need for integrated technology to augment such assessments is described. Indocyanine green fluorescence-guided surgery (ICG-FGS) is a promising tool, given its history, safety, low cost, and accumulated experience in elective settings for many surgeries, to help transform precision surgery into acute settings (trauma and emergency surgery). An updated review is needed based on new evidence outlining the current landscape of ICG in acute settings. Methods: We performed a comprehensive review of literature update in the last two decades through June 2026, covering PubMed, ClinicalTrials.gov, and published societal guidelines, including, but not limited to, the World Society of Emergency Surgery (WSES) consensus position paper and the Society of American Gastrointestinal and Endoscopic Surgeons (SAGES) review. Results: ICG is applicable across the full spectrum of acute surgical care, classified under two principal functions: anatomical mapping (biliary, ureteric, thoracic duct, and vascular structures) and perfusion assessment (bowel and mesenteric ischemia, anastomotic perfusion, pancreatic necrosis, burns, soft tissue, extremity trauma, and organ injury). Emerging and less commonly reported applications include necrotizing fasciitis debridement guidance, traumatic brain injury monitoring, penetrating abdominal trauma, gonadal torsion, fistula detection, damage control surgery, and AI-augmented quantitative fluorescence. The WSES consensus and SAGES meta-analysis provided strong prospective validation to date regarding anastomotic leakage reduction. Current gaps include the absence of standardized dosing protocols in acute settings, limited randomized data, and the subjectivity inherent to qualitative fluorescence interpretation. Conclusions: ICG fluorescence-guided surgery is a safe, low-cost, and rapidly deployable adjunct for emergency surgery. Its breadth of applicability warrants wider consideration and integration into acute surgical workflows to inform surgical decision making based specific considerations including specific indications, evidence support, equipment availability, local expertise, workflow readiness and clinical judgement. Standardized protocols, prospective trials, objective and AI-powered quantification are the research priorities to further clarify its practical role.