The Chimeric Scapulodorsal Vascularized Latissimus Dorsi Nerve Flap for Immediate Reconstruction of Total Parotidectomy Defects With Facial Nerve Sacrifice: Building a New Program and Preliminary Results From 25 Cases

Reconstruction of a Spinal Accessory Nerve Defect Using Vascularized Vastus Lateralis Motor Nerve Graft

Massive resection of a malignant tumor of the head and neck region often requires loss of critical nerves, including the spinal accessory nerve. Recently, vascularized nerve grafts (VNGs) have been used to repair facial and other nerve defects with successful outcomes, even in cases involving factors that can inhibit nerve regeneration, such as radiotherapy. However, the effectiveness of these nerve grafts against postoperative radiotherapy has yet to be explored. We report the first successful case in reconstructing a spinal accessory nerve defect after total left parotidectomy with radical neck dissection, using a vascularized vastus lateralis motor nerve graft and an anterolateral thigh flap based on the lateral circumflex femoral system, with great shoulder function outcomes even after postoperative radiotherapy. A branch of vastus lateralis motor nerve perfused by the accompanying descending branch of lateral femoral circumflex vessel was used as a nerve graft, and was repaired in an end-to-end manner. The patient underwent postoperative radiotherapy to the area of operation. At 6-months follow-up, the patient was capable of 90 degrees lateral shoulder abduction, and at 18 months, achieved full-range shoulder abduction and reported neither functional limitations of the shoulder nor complaints of any shoulder pain (Disabilities of Arm, Shoulder, and Hand score 0). Although further study is necessary to fully understand the superiority of VNGs over postoperative radiotherapy, immediate nerve reconstruction using VNG for accessory nerve defects in patients scheduled for radiotherapy postoperation may be extremely beneficial for preserving shoulder motor function and sustaining the patient's quality of life.

Donors for nerve transplantation in craniofacial soft tissue injuries

Neural tissue is an important soft tissue; for instance, craniofacial nerves govern several aspects of human behavior, including the expression of speech, emotion transmission, sensation, and motor function. Therefore, nerve repair to promote functional recovery after craniofacial soft tissue injuries is indispensable. However, the repair and regeneration of craniofacial nerves are challenging due to their intricate anatomical and physiological characteristics. Currently, nerve transplantation is an irreplaceable treatment for segmental nerve defects. With the development of emerging technologies, transplantation donors have become more diverse. The present article reviews the traditional and emerging alternative materials aimed at advancing cutting-edge research on craniofacial nerve repair and facilitating the transition from the laboratory to the clinic. It also provides a reference for donor selection for nerve repair after clinical craniofacial soft tissue injuries. We found that autografts are still widely accepted as the first options for segmental nerve defects. However, allogeneic composite functional units have a strong advantage for nerve transplantation for nerve defects accompanied by several tissue damages or loss. As an alternative to autografts, decellularized tissue has attracted increasing attention because of its low immunogenicity. Nerve conduits have been developed from traditional autologous tissue to composite conduits based on various synthetic materials, with developments in tissue engineering technology. Nerve conduits have great potential to replace traditional donors because their structures are more consistent with the physiological microenvironment and show self-regulation performance with improvements in 3D technology. New materials, such as hydrogels and nanomaterials, have attracted increasing attention in the biomedical field. Their biocompatibility and stimuli-responsiveness have been gradually explored by researchers in the regeneration and regulation of neural networks.