Effects of anesthetic technique on postoperative pulmonary metastasis in patients undergoing laryngectomy

Abstract Background: Whether laryngeal cancer is directly implanted into the lungs through the respiratory tract during orotracheal intubation remains unclear. The present study aimed to determine whether orotracheal intubation was an independent risk factor for postoperative pulmonary metastasis, recurrences and survival in patients undergoing laryngectomy. Methods: Medical records between January 1, 2006 and December 31, 2016 were reviewed. Patients who underwent orotracheal intubation (intubation group) were matched 1:1 with those who received tracheotomy (tracheotomy group) during the induction of general anesthesia. The primary outcome was postoperative pulmonary metastasis. Secondary outcomes included local recurrences, lymphatic metastasis and overall survival. Data were analysed by Kaplan-Meier curves, log-rank test, hazards regression and Cox regression. Results: Comparing the tracheotomy group and orotracheal intubation group, no statistically significant differences were found in postoperative pulmonary metastasis (P = 0.688), local recurrence (P = 0.215), lymphatic metastasis (P = 0.480) and all-cause death (P = 0.299). Primary cancer site was an independent risk factor for pulmonary metastasis [hazard ratio (HR) 0.29, 95% confidence interval (CI) 0.13-0.68; P = 0.013] and local recurrence (HR 2.69, 95% CI 1.39-5.21; P = 0.003). Unexpectedly, postoperative chemotherapy was an independent risk factor for lung metastasis (HR 7.58, 95% CI 3.11-18.47; P < 0.001) and lymphatic metastasis (HR 5.18, 95% CI 2.57-11.91; P < 0.001). Five-year overall survival was not associated with anesthetic technique (P = 0.473). Conclusions: This retrospective study suggested that orotracheal intubation during laryngectomy was not a risk factor for postoperative pulmonary metastasis, local recurrence and overall survival. Keywords: Anesthetic technique, Postoperative pulmonary metastasis, Laryngectomy