The Turkey Digit: a New Training Model for Digit Replantation
Mohamed Morsy, MD1,2; Si-Gyun Roh, M.D.3,4; M. Diya Sabbagh, M.D.3; Yinxian Yu, M.D.3; Alyssa Vrieze, BA3; Thomas R Meier, D.V.M., M.B.A.3; Brian T. Carlsen, MD2; Peter C. Amadio, MD5; Steven L Moran, MD2; Chunfeng Zhao, MD6; (1)Assiut University, Assiut, Egypt, (2)Division of Plastic Surgery, Mayo Clinic, Rochester, MN, (3)Mayo Clinic, Rochester, MN, (4)Chonbuk National University Hospital, Jeonju, Korea, Republic of (South), (5)Orthopaedic Surgery, Mayo Clinic, Rochester, MN, (6)Department of Orthopedics, Mayo Clinic, Rochester, MN
Introduction:
Finger amputation is the most detrimental injury in hand trauma leading to functional disability. Success rates of digit replantation have declined due to increased cases performed by less experienced surgeons. A training model on this highly demanding skill is not available. This study aimed at developing a clinically relevant and applicable animal model that could be used for training surgeons. We report on our preliminary results in using the turkey digit to simulate replantation surgery.
Methods:
Six mature bourbon red turkeys were used in this study. After induction of anesthesia, they were intubated and maintained on continuous isoflurane inhalation (figure 1). The middle digit was amputated at the level of the mid-proximal phalanx in 4 turkeys and at the level of the mid-metacarpal in 2 (figure 2). Steps of a replant surgery were performed including preparation of the proximal stump and amputated digit, bone shortening and fixation using a k-wire, flexor and extensor tendon repair (Figure 3), repair of the radial and ulnar digital nerves (Figure 4), and anastomosis of the ulnar digital artery and the radial digital vein (Figures 5 & 6). Attempts to isolate and repair veins on the dorsal surface were made. This was followed by skin closure (figure 7) and application of a well-padded cast. The turkeys were placed in a sling to prevent them from bearing weight on the foot and viability of the digit was monitored.
Results:
Anatomy of the turkey digit was very similar to the human digit. A notable difference was the absence of repairable dorsal veins. All the replanted digits survived the immediate post-operative period. All digits survived for at least one day postoperative (range 1 day to 10 days). Venous congestion was accounted for the later failure of the replant, which we think is due to the dependent position of the digit owing to the posture of the turkeys in the sling.
Conclusion:
The turkey digit has a great similarity to human digit anatomically. We believe that the turkey digit replant model is a successful training model, which will aid in promoting surgical skills and ultimately improve nationwide outcomes. Further experimenting with the model is warranted to improve long term survival and outcome.
Figure 1: anesthetized intubated turkey.
Figure 2: amputated digit.
Figure 3: K-wire fixation and tendon repair.
Figure 4: nerve repair
Figure 5: arterial anastomosis:
Figure 6: venous anastomosis.
Figure 7: successfully replanted digit.
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