Author(s)
Roy K. Park, MD
Seth Davis, MD
Mark S. Nyaeme, MD
Fred M. Baik, MD
Sam Most, MD
Tulio A. Valdez, MD
Affiliation(s)
Stanford School of Medicine
Abstract:
Educational Objective: At the conclusion of this presentation, the participants should be able to describe the advantages of short-wave infrared (SWIR) imaging over conventional near-infrared (NIR) angiography for assessing vascularity in paramedian forehead flaps.
Objectives: The paramedian forehead flap is a workhorse in nasal reconstruction, relying on the supratrochlear artery to provide vascularized tissue. Near-infrared (NIR, 700-900 nm) fluorescence angiography with indocyanine green (ICG) is commonly used to assess flap perfusion but can be limited in visualizing small vessels beneath thick tissue, limiting microvasculature details. Short-wave infrared (SWIR) imaging (1000-1400 nm) offers improved tissue penetration, reduced scattering, and lower autofluorescence, potentially enhancing vascular visualization. This study aims to leverage SWIR imaging to improve vascular assessment of paramedian forehead flaps during ICG angiography.
Study Design: Prospective study in a tertiary academic center.
Methods: Conventional NIR images were obtained using the SPY Elite (Stryker) system, while SWIR images were acquired simultaneously with a custom setup (Goldeye G32 or C-RED2 camera) using the same excitation source and long-pass filters from 1050 to 1300 nm.
Results: 8 patients undergoing paramedian forehead flap reconstruction were enrolled. NIR images provided an average contrast ratio of 1.3 when comparing blood vessels to background tissue. Contrastingly, SWIR imaging increased vessel contrast to 1.7 with a 1200 nm long pass. SWIR imaging enhanced vessel contrast and allowed precise differentiation of arteries, veins, and capillaries.
Conclusions: SWIR imaging significantly improved vessel contrast and microvascular visualization compared to conventional NIR imaging. This study represents the first use of SWIR perfusion imaging across multiple wavelengths in paramedian forehead flap reconstruction and suggests that the technology may enhance intraoperative assessments.