Modified Killian Method for Flexible Nasopharyngoscopic Observation of the Hypopharynx: A Systematic Review and Meta-Analysis

Abstract

Objective: Flexible nasopharyngoscopy is a common procedure for evaluating the hypopharynx. The modified Killian method has been reported to enhance visualization during this examination. The aim of this study was to compare the visibility of the hypopharynx using conventional and modified Killian methods. Methods: A systematic literature search was conducted in PubMed, EMBASE, and the Cochrane Library to identify studies that compared the visibility of the hypopharynx using the 2 methods. Comprehensive meta-analysis software was used to analyze the data. Studies that evaluated the overall hypopharyngeal visibility score and the visibility of the pyriform sinus, postcricoid region, and upper esophageal sphincter were included. Results: Five studies were included in the analysis. The pooled results showed that the modified Killian method significantly improved overall visibility score (SMD=1.09; 95% CI, 0.39–1.80) and complete visibility of the pyriform sinus, postcricoid region, and upper esophageal sphincter (log OR=3.83; 95% CI, 2.30–5.35; log OR=4.20; 95% CI, 3.21–5.19; log OR=3.38; 95% CI, 1.68–5.08). Conclusion: The modified Killian method is a valuable technique for improving hypopharyngeal visibility during flexible nasopharyngoscopy. This technique can enhance the detection of potential abnormalities or lesions, leading to better diagnostic accuracy and improved patient outcomes.