Use of Autologous Fat to Improve Functional Outcomes After Upper Limb Nerve Injuries

Traumatic injuries to peripheral nerves are a frequent finding after hand trauma. High morbidity after nerve injuries mainly affects the younger and working population, with consequent decrease in life quality and productivity . Even in direct nerve repair and microsurgical nerve coaptation, regeneration is often suboptimal with incomplete target reinnervation. Suboptimal outcome is attributed to axonal degeneration, fibrotic scar formation, and neuromas at the site of injury. The use of adipose tissue has become very popular in tissue engineering and reconstructive surgery in recent years. It is proposed as a "regenerative tool" for various tissues, including peripheral nerves, because it offers an effective and minimally invasive procedure for obtaining stem cells. Unprocessed fat grafting can provide a simple approach to improve peripheral nerve regeneration by means of neoangiogenesis \& inflammatory response modulation. Furthermore, it serves as a good protective barrier in peripheral nerve surgery, reducing fibrosis and adhesions. A recent study advocated by Tuncel et al, concluded that combined use of autologous fat graft with surgical repair methods induced significantly better regeneration in rats \[3\]. In another study by Kilic et al, using adipose tissue flap in a crush injury model in rats was found to be superior to other groups in myelin thickness, nerve fiber density, axon count, and functional recovery at 4 weeks. They concluded that fat tissue seems to promote nerve regeneration because of its stem cell content. To our knowledge, no prior studies have examined the use of fat graft in peripheral nerve repair in humans. So, the investigators proposed this clinical study to evaluate the outcomes of primary nerve repair combined with autologous fat graft in peripheral nerve injuries.