Materials and methods
The clinical data of 93 patients who underwent primary pyriform sinus carcinoma resection via the paraglottic space approach, from January 2014 to January 2017 were retrospectively analysed. All patients were operated for the first time without preoperative chemoradiotherapy and underwent electronic laryngoscopy, narrow band imaging, electronic gastroscopy and cervicothoracic enhanced CT before surgery. Patients with distant metastasis or second primary cancer and general anaesthesia contraindications were excluded from this study. The age of the patients ranged from 41 years to 87 years. Amongst the 93 patients, 91 were males and 2 were females with an average age of 58.8±9.51 years. The general clinical data and tumour characteristics of all patients (in accordance with the American Joint Committee on Cancer 2017 8th edition TNM staging of hypopharyngeal carcinoma) are summarised in Tables 1–2. The STROBE standard reporting guidelines for cohort studies were followed.