[Endoscope-assisted transoral resection of parapharyngeal space tumors: a retrospective study].

Objective:To evaluate the feasibility and safety of the endoscope-assisted transoral approach for the parapharyngeal space（PPS） tumors. Method:This retrospective study included 22 patients who were diagnosed with PPS tumors and treated with the endoscope-assisted transoral approach. Result:The postoperative pathological diagnosis included 10 cases of schwannoma, 7 cases of pleomorphic adenoma, 1 case of paraganglioma, 1 case of branchial cleft cyst, and 3 cases of malignant tumors for a diagnostic purpose. The surgical duration was between 15 minutes and 430 minutes（median duration 105 minutes）, and the intraoperative bleeding was between 10ml to 500ml（median bleeding 20 mL）. Complete resection with minor complication was performed in 21 cases, 1 case of recurrent schwannoma was done in an incomplete style because of intraoperative massive bleeding. With a 12-to-72-months follow up, there was no relapse on the 18 cases of benign tumor which were completely resected. Conclusion:Endoscope-assisted transoral resection provide cosmetic, micro-invasive and increased operative exposure to the PPS, especially for the benign tumors that medial to the carotid sheath. But is not recommend for relapsed cases and lesions that encompassing or lying posterolateral to the carotid sheath.