Efficiency of Tissue Biopsies in the Larynx and Hypopharynx: A Comparative Study between the Use of Transnasal Flexible Laryngoscope Versus Direct Laryngoscope

Abstract

Background: Laryngeal and hypopharyngeal biopsies are traditionally performed with direct laryngoscope (DL), however the transnasal flexible laryngoscope (TFL) is now increasingly used. Objective:To determine the efficiency of laryngeal/ hypopharyngeal biopsies via the office-based TFL versus the gold standard DL. Methods: Retrospective data collection from patient records including histopathology result among 92 patients underwent laryngeal/hypopharyngeal biopsies at Mae Sot Hospital, from 1^st October 2015 to 30^th September 2021. Results: Of the 92 patients, 110 biopsies were performed. Biopsies via TFL showed 75%-sensitivity, 100%-specificity and overall accuracy, as represented by area under receiver operating characteristic (AuROC), was 0.88. In comparison, biopsies via DL presented the sensitivity of 94.6%, 100%-specificity, and AuROC was 0.97. Additionally, TFL biopsies costed significantly less than DL [median (IQR): 2258.5 (1470, 2930) versus 14076.5 (9607, 29138.5) BHT, respectively, p<0.001]. The waiting time for TFL biopsies was approximately 4.5 days shorter than DL. Time for diagnosis by TFL vs DL in the malignant group were significantly different [median (IQR): 8.5 (6, 19) vs. 13 (9, 18), respectively, p=0.044]. The both procedures had low incidences of complications and were not different. Conclusion: Office-based biopsy under local anesthesia using TFL is safe, lower cost and reducing diagnosis work up time. Due to less validity on obtaining tissue from suspicious lesion located on larynx or hypopharynx by TFL than DL, all patients with highly suspicious of malignant lesion should undergo DL biopsy performed for accurate diagnosis if the result from TFL biopsy is benign or CIS.