"Blue-Blood"- Infused Chicken Thigh Training Model for Microsurgery and Supermicrosurgery.

Supplemental Digital Content is available in the text.

Dear Sir:

Microsurgical training models are essential in helping trainees become familiar with the instruments and techniques of the craft. The current gold standard, the live laboratory rat, excels in technical simulation but is often prohibitively expensive, with high variability in “return” dependent on the trainee’s skills. As such, the concept of training on the femoral structures of store-bought chicken thighs has been entertained for decades. This model was recently reestablished in 2007 by Marsh et al.[1] and further characterized for supermicrosurgery by Chen et al.[2] This model has been well received due to significant advantages in material availability, price, and minimal location and scheduling requirements.[3] Nevertheless, a major deficiency remains: the inability to realistically simulate vessel perfusion. Current methods are limited to repeated postrepair syringe injection[4] and the use of a pulsatile membrane pump.[5] Yet still, the limits of frank injection and the need for specialized equipment, power supplies, and digital monitors leave more to be desired.

Therefore, we have devised a simple method of bag infusion with gravity pump to perpetually or intermittently mimic real-time blood flow. This can be performed in any microsurgical suite, requires few and readily available materials, takes ≤5 minutes to set-up, and will reliably perfuse up to tertiary vessels for practicing supermicrosurgery. The requisite materials are shown in Figure 1. To prepare, inject 1 mL of blue food coloring for every 500 mL of fluid into 1 intravenous “drip” bag and elevate it above the field. Place the other “collection” bag below the field and connect angiocatheters to both bags. Prepare the chicken thigh by isolating the neurovascular bundle located parallel to the femoral bone. (Refer to Couceiro et al.[4] for relevant chicken anatomy and techniques.) Insert and suture the cut angiocatheter tubing into the proximal and distal ends of the artery. For end-to-side and side-to-side capabilities, ligate the proximal vein and connect angiocatheter tubing to the distal vein. Cautery of the tubing may be helpful to create “mace-like” surface defects for improved intimal grip. To perfuse when desired, simply run the drip at approximately 10 drops per minute. For venous capabilities, clamp the distal artery angiocatheter and attach the collection bag to the vein angiocatheter. The bags and tubing can be used indefinitely with additional food coloring and swapping of bag locations.

Fig. 1.

Materials required for the conversion of the standard microsurgical chicken thigh model into our blue-blood variant: (A) 2 bags of intravenous fluids with tubing (eg, 500-ml of Lactated Ringer’s); (B) the tubing of 2–3 angiocatheters (eg, Saf-T E-Z Set, 21G; Becton Dickinson, Sandy, UT); (C) blue food coloring; (D) needle (eg, 24 gauge); (E) syringe (eg, 3 mL); and (F) suture (eg, 5-0). Bone-in chicken thigh and standard microsurgical instruments and supplies were not pictured.

Continuous “blue-blood” mimics the viscerality of live surgery, gives immediate feedback if vessels are mismanaged, and allows for the novel training of clamp placement on engorged vessels. Trainees may repeatedly practice multiple end-to-end, end-to-side, and side-to-side anastomoses on vessels 3 to 0.3 mm in diameter, and have free-flowing, high-contrast blue-blood readily available for the detection of leaks (Fig. 2). We have had a positive response to this model at our institution (See video, Supplemental Digital Content 1, which displays a demonstration of this model in use. This video is available in the “Related Videos” section of the Full-Text article on PRSGlobalOpen.com or available at http://links.lww.com/PRSGO/A708) and are currently investigating its objective superiority. In conclusion, our blue-blood chicken thigh model is simple, cost-effective, and offers a significantly more realistic training experience. This theoretically translates to improved confidence and competence in trainee skills before progressing to live animal and human surgery.

Fig. 2.

Examples of completed and perfused (A) end-to-end, (B) end-to-side, (C) side-to-side, and (D) supermicrosurgical end-to-end anastomoses possible with our blue-blood chicken thigh model.

See video, Supplemental Digital Content 1, which displays a blue-blood chicken thigh model in use for microsurgical training at our institution. This video is available in the “Related Videos” section of the Full-Text article on PRSGlobalOpen.com or available at http://links.lww.com/PRSGO/A708.