[Retropharyngeal lymph node dissection in head and neck cancers treated with transoral robotic surgery]

Objective: To evaluate the indications, safety, feasibility, and surgical technique for patients with head and neck cancers undergoing transoral robotic retropharyngeal lymph node (RPLN) dissection. Methods: The current study enrolled 12 consecutive head and neck cancer patients (seven males and four females) who underwent transoral robotic RPLN dissection with the da Vinci surgical robotic system at the Sun Yat-sen University Cancer Center from May 2019 to July 2020. Seven patients were diagnosed as nasopharyngeal carcinoma with RPLN metastasis after initial treatments, 4 patients were diagnosed as thyroid carcinoma with RPLN metastasis after initial treatments, and one patient was diagnosed as oropharyngeal carcinoma with RPLN metastasis before initial treatments. The operation procedure and duration time, intraoperative blood loss volume and complications, nasogastric feeding tube dependence, tracheostomy dependence, postoperative complications, and hospitalization time were recorded and analyzed. Results: All patients were successfully treated by transoral robotic dissection of the metastatic RPLNs, none of which was converted to open surgery. RPLNs were completely resected in 10 patients, and partly resected in 2 patients (both were nasopharyngeal carcinoma patients). The mean number of RPLN dissected was 1.7. The operation duration time and intraoperative blood loss volume were (191.3±101.1) min and (150.0±86.6) ml, respectively. There was no severe intraoperative complication such as massive haemorrhage or adjacent organ injury during surgery. Nasogastric tube use was required in all patients with (17.1±10.6) days of dependence, while tracheotomy was performed in 8 patients with (11.6±10.7) days of dependence. The postoperative hospitalization stay was (8.5±5.7) days. Postoperative complications occurred in 4 patients, including 2 of retropharyngeal incision and 2 of dysphagia. During a follow-up of (6.5±5.1) months, disease-free progression was observed in all patients, 10 patients were disease-free survival and other 2 patients were survival with tumor burden. Conclusions: The transoral robotic RPLN dissection is safety and feasible. Compared with the traditional open surgical approach, it is less traumatic and safer, has fewer complications and good clinical application potentiality. The indications for transoral robotic RPLN dissection include thyroid carcinoma, oropharyngeal carcinoma, and some selected nasopharyngeal carcinoma and other head and neck cancers. Metastatic RPLNs from some nasopharyngeal carcinoma with incomplete capsule, unclear border and adhesion to the surrounding vessels are not suitable for transoral robotic RPLN dissection.