Narrow Band Imaging: Demonstration of Laryngeal Micro‐vascularization in Normal and Pathological Conditions

Abstract

Objectives: With blue and green light only, narrow band imaging (NBI) allows better visualization of mucosal micro-vascular architecture. Intra-epithelial papillary capillary loops (IPCL) is a classification of vascular patterns based on previous esophageal NBI studies. The aims of the study were to: (1) Study the normal micro-vascular anatomy of the larynx by means of NBI. (2) Better understand the clinical applications of NBI in laryngeal lesions. (3) Assess the relative advantages and disadvantages of NBI versus white light imaging in the larynx. (4) Assess the relevance of previously described IPCL classification in laryngeal pathologies. Methods: A prospective comparative study including patients who arrived for laryngeal examination at an ENT referral center in 2013. White light images and NBI were compared in each patient to assess relative advantages of each modality. Micro-vascular architecture was described by IPCL classification. Results: A total of 110 patients were included and underwent video-stroboscopy, flexible distal-chip endoscopy, and NBI of the larynx. Thirty-two patients had a normal larynx, 54 had benign conditions, and 24 had malignant lesions. Distinct characteristics of vascular patterns were visualized by NBI in normal tissues, as well as a wide spectrum of benign and malignant conditions. In several patients with malignant and premalignant conditions, NBI revealed more extended disease than what was observed by white light imaging. Conclusions: Using NBI along with white light imaging, while understanding the unique microvascular fingerprint of each laryngeal pathologic condition, can assist the physician in differential diagnosis. In specific conditions, including malignant and premalignant lesions, NBI can bring better assessment of lesions’ size and extension.