BACKGROUND: The skills required for supermicrosurgery are hard earned and difficult to master. The University of Wisconsin “blue-blood” chicken thigh model has proven to be an excellent source of small vessels (down to 0.25 mm) but assessing the quality of anastomoses at this spatial scale has proven difficult.1 Without the capacity for self-assessment, the chicken thigh model becomes a much less effective training tool. We evaluated whether augmentation of this realistic training model with fluorescent imaging would enhance assessment of supermicrosurgical anastomoses, and therefore improve real-time feedback to trainees.
METHODS: White light with and without fluorescence imaging overlay captured the infusion of colored saline and fluorescent indocyanine green “blood” through the vessels (n = 7 with diameters ranging from 0.35 to 0.55 mm). Videos with and without fluorescence overlay were separated, randomized, and shown to 7 fellowship-trained microsurgeons at the University of Wisconsin-Madison who rated each anastomosis as “patent”, “not patent” or “unsure.” Surgeon accuracy, uncertainty, and inter-rater agreement were measured to evaluate the effectiveness of each imaging modality for assessing supermicrosurgical anastomoses. Staff opinion regarding the use of fluorescent imaging was also polled using a Likert scale.
RESULTS: When assessing the quality of supermicrosurgical anastomoses, the use of fluorescence significantly increased surgeon accuracy to 91% compared with 47% with white light alone (P = 0.015), significantly decreased surgeon uncertainty to 4% compared to 41% with white light alone (P = 0.011), and significantly improved inter-rater agreement to 91.2% compared with 53.0% with white light alone (P = 0.016). Additionally, 100% of participating surgeons “strongly agreed” that the use of fluorescence improved their ability to assess the patency of anastomoses. All of the participating surgeons either “agreed” (43%), or “strongly agreed” (57%) that the use of fluorescence improved their ability to assess for anastomotic leaks.
CONCLUSIONS: Augmentation of the University of Wisconsin “blue-blood” chicken thigh model with indocyanine green fluorescence significantly improves accuracy, decreases uncertainty and improves inter-rater agreement when assessing supermicrosurgical anastomoses in a training setting. Now, with fluorescence, the “blue-blood” chicken thigh model is capable of providing high quality, real-time feedback at the supermicrosurgery scale, redeeming it as an effective training tool for supermicrosurgery skills.
REFERENCE:
1. Zeng W, Shulzhenko NO, Feldman CC, et al. “Blue-blood-” infused chicken thigh training model for microsurgery and supermicrosurgery. Plast Reconstr Surg Glob Open 2018;6:e1695–1693.