[Transoral robotic surgery for parapharyngeal space neoplasm: a report of 7 cases]

Objective: To evaluate the safety, efficacy and feasibility of transoral robotic surgery (TORS) for parapharyngeal space (PPS) neoplasms. Methods: We collected data from 7 patients with PPS neoplasm who received TORS in Sun Yat-sen University Cancer Center between May 2017 and November 2020, and patients' clinical and pathological characteristics were analysed. There were 2 men and 5 women with age ranged from 35 to 76 years. Among them, 2 patients underwent secondary surgery, 2 patients required combined transcervical approach to complete surgery, and 1 patient was suspected of ipsilateral cervical lymph node metastasis and scheduled for diagnostic TORS. The preoperative tumor size, operation time, intraoperative blood loss, postoperative bleeding, dyspnea, neurological impairment, feeding time and postoperative hospital stay were analyzed. SPSS 24.0 was used to analyze the data. Results: TORS was performed successfully with complete removal of tumors in all 7 cases. Among 6 patients with curative TORS, 5 patients received TORS with postoperative diagnoses of neurogenic tumors and 1 patient underwent TORS combined transcervical approach with postoperative disgnosis of recurrent pleomorphic adenoma; no intraoperative tumor rupture occurred; the intraoperative blood loss was 20-200 ml with a median of 40 ml; the operation time was 65.0-238.0 min with a median of 77.5 min; the oral feeding time was 3-6 days with a median of 3 days; and the postoperative hospital stay was 4.2±1.6 days. One patient presented with neck swelling 3 days after surgery, but this symptom relieved 3 days later after treatments with antibiotic, hemostasis and detumescence. One patient received diagnostic TORS, as intraoperative pathology indicating a recurrent pleomorphic adenoma, then the neoplasm got completely resected through transcervical-transparotid approach. None of 7 patients manifested with airway obstruction, bleeding or nerve injury symptoms after operation. All patients were followed for 2 to 44 months, no local recurrence or distant metastasis was found. Conclusions: TORS is a safe, effective and feasible treatment for selected PPS neoplasms, with less cosmetic impact, less trauma and blood loss, few postoperative complications, enhanced postoperative recovery and short hospital stay.