Multimodal Microvascular Mapping for Head and Neck, Skull Base Research and Education: An Anatomical Donor Study

Objective  This study was aimed to develop a method combining computed tomography (CT) and fluorescence imaging, allowing identification of microvasculature in anatomical donors and facilitating translational research and education. Methods  We investigated homogeneity and radiopacity of 30 different mixtures including radiopaque substances povidone-iodine (Betadine), barium sulfate (BaSO ₄ ), and bismuth subsalicylate (Pepto-Bismol) varying in suspension and dilution with agar, latex, or gelatin. Three candidate mixtures were selected for testing the extent of perfusion in renal vasculature to establish methodology. From these candidate mixtures, two were selected for mixture with fluorescein and infusion into cadavers based on their ability to perfuse renal vasculature. The extent to which these two candidate mixtures combined with fluorescein were able to perfuse vasculature in a cadaver head was used to determine which mixture was superior. Results  BaSO ₄ and bismuth subsalicylate-based mixtures demonstrated superior opacity in vials. In terms of solidifying agents, gelatin-based mixtures demonstrated increased friability and lower melting points compared with the other agents, so only latex and agar-based mixtures were used moving forward past the vial stage. Combinations of BaSO ₄ and latex and BaSO ₄ and 3% agar were found to perfuse kidneys superiorly to the mixture containing bismuth subsalicylate. Finally, in cadaver heads, the mixture containing BaSO ₄ , agar, and fluorescein was found to perfuse the smallest vasculature. Conclusion  A final combination of BaSO ₄ , 3% agar, and fluorescein proves to be a powerful and novel combination enabling CT imaging, fluorescence imaging, and dissection of vasculature. This paves the way for future translational research and education.