Author: Logan M. Bateman, Xu Cao, Jonathan T. Elliott, Lillian A. Fisher, Ida Leah Gitajn, Xinyue Han, Eric R. Henderson, Shudong Jiang, Jessica M. Sin, Yue Tang 👨🔬
Affiliation: Dartmouth College, Dartmouth-Hitchcock Medical Center 🌍
Purpose: Adequate tissue perfusion is essential for fracture healing and infection prevention, as it supplies oxygen, nutrients and antibiotics to the injury area. However, current methods of assessing bone perfusion during the surgery are subjective, leading to inconsistent decisions regarding how much damaged tissues to remove, and variability in treatment outcomes. This study evaluated the use of indocyanine green (ICG)-based dynamic contrast-enhanced fluorescence imaging (DCE-FI), a non-ionizing, real-time and objective imaging technique, using a simulated fracture model in patients undergoing amputation.
Methods: Fifteen adult patients scheduled for lower limb amputations were enrolled. Three clinically relevant conditions were created sequentially to simulate increasing severities of trauma: baseline, a bone cut (osteotomy), and a bone cut plus the removal of superficial soft tissue (periosteal stripping). For each condition, patients received an intravenous dose of 0.1 mg/kg of ICG, followed by 4.5-minute imaging of DCE-FI. Simultaneously, arterial input function (AIF) was recorded to measure ICG concentration over time in the arterial system. Key perfusion variables, including maximum fluorescence intensity (Imax) and blood flow, were derived and compared across the three conditions.
Results: Perfusion, assessed through Imax and blood flow, significantly decreased after osteotomy and further declined following periosteal stripping, compared to the baseline (p<0.001). Receiver operating characteristic (ROC) analysis showed strong classification of injury severities, with an area under the curve (AUC) of 0.90 for Imax and 0.89 for blood flow.
Conclusion: Intraoperative ICG-based DCE-FI can effectively characterize trauma-related changes in bone perfusion. This technique shows potential in providing surgeons with objective, real-time perfusion data to guide surgical decisions, optimize debridement extent and minimize infection risks.