Neuronal structure of microvascular transplants with and without neuronal anastomosis

Objective. Latissimus dorsi transplants have little neuronal regenerative c apacity without neuronal anastomosis. Histologic differences between transp lants with and without neuronal anastomosis and 2 distinct types of neurosu rgical reanastomosis are highlighted in this study. Patients and methods. Fifty-four patients with squamous cell carcinomas of the oral cavity (T4) were treated by tumor resection and homolateral neck d issection. The defect was covered with a microvascular latissimus dorsi tra nsplant. In 15 patients, no neuronal anastomoses were performed. In 21 pati ents, the thoracodorsal nerves were used for microneurosurgical reanastomos is, whereas in 18 patients, the cutaneous branches of the intercostal nerve s were used for microneurosurgical reanastomosis. The transplant was examin ed during surgery and 9 months after surgery by means of a histologic exami nation of a biopsy specimen. The number of fascicles, the degree of fibrosi s, and the myelination were examined. Furthermore, a neurosensory examinati on was performed 9 months after surgery. Results. Overall, our patients had an average of 12.1 fascicles during surg ery. After surgery, patients without neuronal anastomosis showed an average of 4.9 fascicles, patients with nerve anastomosis to the cutaneous branche s of the intercostal nerve showed an average of 6.2 fascicles, and patients with anastomosis to the thoracodorsal nerve showed an average of 9.6 fasci cles. In cases of nerve anastomosis, a lesser degree of fibrosis was found, together with good myelinization. The clinical examination showed the best neurosensory function in the transplants with anastomosis to the thoracodo rsal nerve and the worst function in those without neuronal anastomosis. Conclusion. Neuronal reanastomosis led to more surviving neuronal structure s in the postoperative histologic specimen. The highest density of fascicle s was found in the well vascularized thoracodorsal nerve. The neurosensory function agrees with the histologic result.