Water-soluble dye staining of the flap nutrient artery and its perforator branch in cadavers embalmed using saturated salt solution and urea methods: does demonstration using a dye-stained cadaver increase a trainee's level of skill acquisition?

Cadaveric surgical training (CST) can safely improve surgical skill. Recently, various innovations have made surgical training more realistic. Saturated salt solution (SSS) and urea methods are useful for plastic surgery training, because they better preserve the color and texture of soft tissues than formalin fixation (FA). Microvessels are invisible to the naked eye, and in this study, we visualized skin perforators by injecting dye into the flaps of nutrient vessels during hand and foot surgery. During each CST session, the instructor used three cadavers for demonstration. From 2017 to 2021, these cadavers were not stained, whereas from 2022 to 2023, the cadavers were stained to enhance the visualization of nutrient and perforating vessels. We compared the self-rated skill gains of participants who observed demonstrations on unstained cadavers from 2017 to 2021 and participants who observed demonstrations on stained cadavers from 2022 to 2023. Among 36 participants from the 2022-2023 group, 28 rated the staining of nutrient vessels and perforating branches as adequate. Of 32 participants, 29 preferred the use of dyed cadavers during training. Trainee skill increase for the digital artery flap, reverse digital artery flap, and dorsal metacarpal artery perforator flap was significantly higher in 2022-2023 (with stained cadavers) than in the earlier course without stained cadavers. SSS-fixed and urea-treated cadavers combined with vascular staining may be useful training models for flap elevation.