Augmentation of Chicken Thigh Model with Fluorescence Imaging Allows for Real-Time, High Fidelity Assessment in Supermicrosurgery Training

Abstract

Background The skills required for supermicrosurgery are hard-earned and difficult to master. The University of Wisconsin “blue-blood” chicken thigh model incorporates perfusion of the thigh vessels with a blue liquid solution, allowing users to visualize flow across their anastomoses. This model has proven to be an excellent source of small vessels (down to 0.3 mm) but assessing the quality of anastomoses at this spatial scale has proven difficult. We evaluated whether fluorescent imaging with indocyanine green (ICG) in this realistic training model would enhance the assessment of supermicrosurgical anastomoses, and therefore improve real-time feedback to trainees. Methods Anastomoses of vessels ranging from 0.35 to 0.55mm in diameter were performed followed by the capture of white light with and without fluorescence imaging overlay during infusion of “blue-blood” and ICG. Videos were randomized and shown to seven 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 for each imaging modality. Results Use of fluorescence significantly increased surgeon accuracy to 91% compared with 47% with white light alone (p = 0.015), decreased surgeon uncertainty to 4% compared with 41% with white light alone (p = 0.011), and improved inter-rater agreement from 53.1% with white light alone to 91.8% (p = 0.016). Conclusion Augmentation of the University of Wisconsin “blue-blood” chicken thigh model with ICG fluorescence improves accuracy, decreases uncertainty, and improves inter-rater agreement when assessing supermicrosurgical anastomoses in a training setting. This improved, real-time feedback enhances this model's value as a supermicrosurgical training tool.

Evaluation of a Microsurgery Training Curriculum

“…Current microsurgical simulation and curricula predominantly 3 4 15 evaluate one aspect: technical performance, including assessment with lower fidelity models on synthetic and ex-vivo tissue, tracking and showing progression with objective assessment tools. 16 17 One study 18 perfused an ex-vivo chicken model with “blue blood” indocyanine green (ICG) fluorescence dye and experts assessed the patency of the vessel, this provides a high-fidelity model without the use of a live animal. It differs from our study in that participants' proficiency was assessed purely on the outcome, that is, anastomosis patency, without any ability to provide formative feedback on technique to improve.…”

Establishing a Lymphatic Venous Anastomotic Training Model in Pig Trotters

“…[6][7][8] To ensure the patency of tiny vessels, ICG has been reported as a useful method for visualization, even in the dead chicken model. 9 However, anastomoses were not available with lymphatic tissues, and the total volume of the model was too small to simulate clinical LVA. Furthermore, birds were not a feasible model for LVA training because their collecting lymphatic system is very different from that of humans.…”

Evaluation of a Full-Time Microsurgeon Educator on Resident Training, Research Collaboration, and Grant Funding

“…One criticism of the BBCT simulator is that patency assessment may remain difficult with super microsurgical anastomoses. Augmenting the model with florescent imaging and indocyanine green dye allows the learner to reliably assess anastomoses down to 0.4 mm more reliably 18 . Additionally, our group has published the needle technique for learners to practice making arteriotomies and venotomies for end-to-side anastomoses using the BBCT.…”