Distal chip versus fiberoptic laryngoscopy using endoscopic sheaths: Diagnostic accuracy and image quality

Laryngeal visualization is the hallmark in the diagnostic approach of laryngeal disease. In addition to fiberoptic techniques, digital distal chip technology has been developed to improve visualization. Endoscopic sheaths are used in daily clinical practice to prevent cross-contamination. The objective of the study was to evaluate diagnostic accuracy, image quality and interrater reliability of both flexible distal chip laryngoscopy (DCL) and flexible fiberoptic laryngoscopy (FOL) using contamination preventing endoscopic sheaths. In 53 cases both DCL and FOL images were collected during routine examination using endoscopic sheaths. All images were randomly shown to four experts in the field of laryngology and head and neck oncology. Observers were asked to choose a diagnosis, express their confidence level of that diagnosis and validate image quality: in this way 420 observations (four observers using two techniques) were analyzed. Accuracy in detecting laryngeal disease was 78 % (both DCL and FOL). Confidence level of diagnosis tended to be higher in DCL (p = 0.05). Image quality was validated better in DCL as compared to FOL (p <0.05). Interrater agreement in identifying laryngeal disease was 1.5 times higher in DCL (kappa = 0.44) as compared to FOL (kappa = 0.29). In this study, reflecting daily clinical setting using sheathed endoscopes, DCL is identical to FOL regarding diagnostic accuracy, but DCL is superior to FOL in image quality and interrater reliability.