Innervated Free Gracilis Muscle Transfer: An Experimental Model

Although rodent models have been used extensively for surgical research, their use is limited in microsurgical tissue transfer due to their small size and the small size of their vessels and nerves. Also, fundamental anatomic differences may make rodent surgical models hard to extrapolate to humans. In this report, the authors present a rabbit model for studying free tissue transfer and nerve regeneration using the innervated free gracilis muscle flap. In providing this report, the authors are hopeful that this model could become a standard investigative method for future investigators to employ in other translational endeavors. The authors have completed 12 innervated gracilis muscle transfers with 2 surgical site infections requiring antibiotic treatment and postoperative wound care. There were no complications related to flap-viability in the study over an average follow-up of 9 months. The return of muscle function with nerve coaptation is seen initially around 12 weeks and complete return of function occurs by 20 weeks. Rabbits are comparatively small, easily available, easy to handle, and cost-effective experimental models. Use of the innervated gracilis muscle free flap in rabbits can provide an excellent and economic model for free tissue transfer and reinnervation studies.