Tongue Transplantation: 10-Month Follow-up

Field: Medicine (Health Sciences)

In cases of bilateral tumor infiltration of the base of the tongue, glossectomy is indicated. Because this procedure leads to severe functional deficits and to diminished quality of life, surgical therapy is often avoided. Instead of multimodal therapy, alternative methods of treatment are employed. These include intraarterial chemotherapy or radiochemotherapy (RCT) in most cases. Without posttherapeutic histological examination, however, it is not possible to determine whether a carcinoma responds to RCT. Because nonresponders have to be regarded as high-risk patients for recurrence and may benefit from further therapy, multimodal therapy should be favored whenever possible (1). Randomized trials have shown that a combination of concomitant RCT and surgery is more effective than radiotherapy alone (2) and surgical therapy alone (3). Defects caused by partial resection of the tongue are commonly covered by revascularized jejunal flaps. The flexibility of this graft and its individual adaptation to the oropharyngeal topography combined with almost unlimited transplant supply leads to satisfying results (4). Other reconstructive techniques include the radial forearm free flap (5, 6), as well as the latissimus dorsi flap. In cases of total glossectomy, existing methods of tissue transfer fail to achieve the goals of anatomical restoration and functional rehabilitation. Therefore, efforts have been made to accomplish these goals. In 1999, Haughey et al. (7) showed the feasibility of a hemitongue allotransplantation in an animal model. The results of this study encouraged us to perform a microneurovascular allotransplantation of a human tongue after receiving approval of the ethics committee. A 42-year-old man presented to our department with a squamous cell carcinoma of the tongue with infiltration of the floor of the mouth and the mandible (T4N2bM0). Preoperative RCT was performed. After a recovery interval of 6 weeks after irradiation, bilateral selective neck dissection (SND) of the levels 1–3 and en bloc resection of the tumor was performed (Fig. 1A).FIGURE 1.: Resected tumor including the right body of the mandible (A), tongue allograft (B), and postoperative appearance (C).Harvesting of the cadaveric tongue from a donor was performed simultaneously by a bilateral submandibular approach. Donor and recipient were matched for blood type only. The hypoglossal and lingual nerves were dissected as well as the lingual arteries. The graft was subsequently removed and rinsed with cold Custodiol (Fig. 1B). The graft was then fixed to the recipient site and microvascular anastomoses were performed to the facial vessels on both sides. The hypoglossal nerves and the left lingual nerve were sutured to the corresponding nerve ends using 10/0 epineural sutures. The right lingual nerve could not be reconstructed since it had to be resected on the level of the condylar neck. Cold ischemia was 245 min. During transplantation, the patient was administered 1 g methylprednisolone. Postoperatively the immunosuppressive therapy was started with antithymocyte globulin (ATG) for a period of 5 days. Subsequently, the regimen was changed to a combination of tacrolimus (2×6 mg), mycophenolat mofetil (2× 500 mg), and prednisolone (20 mg) daily. Total time of hospitalization was 4 weeks. Neither wound healing impairment nor graft rejection was observed (Fig. 1C). Three weeks postoperatively, electrostimulation of the tongue using triangular current was initiated by the use of surface electrodes and continued for 5 months. Simultaneously, logopedic therapy was performed. Upon histological examination, resection margins were free of vital tumor. Response was classified as regression grade 4 (nonresponder) (8). Recovery was assessed 10 months postoperatively by clinical and radiological investigation and electromyographic (EMG) study. The patient was free of recurrence; neither metastases nor de novo malignancies could be observed. He was able to speak intelligible and swallow saliva. The patient reported superficial sensitivity with sharp and blunt discrimination on the left side of the tongue and could differentiate caloric stimuli. Motility of the tongue was not observed. Accordingly, needle EMG examination revealed pathological spontaneous activity only. The patient was able to swallow small amounts of pulpy foods. Videofluoroscopy showed diminished mobility and missing tongue-to-palate contact with poor bolus preparation. Pre- or postdeglutitive aspiration did not occur. Twelve months after the transplantation, tumor recurrence was found in the right neck. Due to an ipsilateral paresis of the facial nerve, surgical intervention was avoided. The patient died 13 months after the operation at home, most likely caused by pulmonary embolism. An autopsy was not performed. The goal of surgical tumor therapy—radical en bloc resection with safety limits and primary anatomical and functional reconstruction—faces several obstacles in cases of glossectomy. Due to the unique structure and function of the tongue, glossectomy patients are often left with significant deficits in speech and swallowing. In the case presented, mutilation of the patient was avoided by anatomical restoration of the oral cavity. Although it was not possible to achieve reneurotization of the muscles of the allograft, the anatomical unit of the larynx, the hyoid and the tongue were reestablished, thus gaining good compensation of the impairment of oral and pharyngeal swallowing. Immunosuppressive therapy remains a major problem in carcinoma patients. In particular, these patients are prone to infections, side effects of their medications, and an increased incidence of certain de novo malignancies (9). Although a high percentage of posttransplant tumors are low-grade malignancies, cancer has become a major cause of death in immunosuppressed transplant recipients (10). The problematic nature of allotransplantation in carcinoma patients is well known as lung or liver transplantations have been carried out under the circumstances of a malignant tumor of these organs (11, 12). The tongue is not a vital organ and therefore the benefits of an allotransplantation in tumor patients have to be evaluated carefully. Successful cancer therapy, however, is not only judged by freedom of reccurrence, but also by quality of life (13). The goal of this new reconstructive technique was not only to obtain coverage of the defect, but also to reach functional rehabilitation, thus sustaining at least moderate quality of life by enhancing the approved therapy by an allotransplantation. Independent of the final result of this case, further transplantations have to be performed to estimate whether the method can be clinically established. Christian Kermer Franz Watzinger Michael Oeckher Medical University of Vienna Department of Craniomaxillofacial and Oral Surgery Vienna, Austria