Office Rigid Laryngoscopy as a Predictor for Glottic Exposure in Microlaryngoscopy

Good glottic exposure is a prerequisite for a good microlaryngeal surgery. Often this is difficult to predict preoperatively. This study aims to evaluate the utility of office-based rigid laryngoscopy (70°) as a screening tool to predict laryngeal exposure during micro laryngoscopy. Sixty-nine patients underwent office-based rigid laryngeal examination followed by micro laryngoscopic surgery for benign vocal cord lesions. Office-based laryngoscopy was classified as grade 1 when the entire glottis with anterior commissure (AC) was visualized without undue traction of tongue; grade 2 when AC was visualized only during phonation and with some traction of tongue and grade 3 when there is an inability to visualise the glottis adequately despite moderate traction of tongue and the examination was completed using a flexible scope. These were correlated with laryngeal exposure during micro laryngoscopy. 42 patients were categorized as grade 1 out of which 39 (93%) had a favourable laryngeal exposure (class 1) while only 3 (7%) had a partially favourable exposure (class 2). 18 patients were categorized as grade 2 out of which 12(66%) had a favourable exposure (class 1) as against 6 (33%) who had a partially favourable exposure (class 2). Nine of our patients were categorized as grade 3 out of which all 9 (100%) had an unfavourable exposure (class 3) requiring angled tele laryngoscopy to complete the surgery. A strong correlation between office-based laryngoscopic grading and exposure during operative laryngoscopy was obtained statistically (Cramer's V test, V = 0.746). Office examination with a 70° telescope is a good predictor of glottic exposure during micro laryngoscopy. We believe that the ease of performing a micro laryngoscopy in the operating room is directly proportional to the ease of doing laryngoscopy in the office.