How Much We Miss in Stroboscopy: A Prospective Study

Aim: To study the accuracy of the diagnosis of structural lesions of the endolarynx, by videostroboscopy (VSS) by finding out the percentage of difference in diagnosis between VSS and examination under anesthesia and the incidence of a second lesion missed by VSS. Materials and methods: A prospective analytical study conducted in the department of laryngology in a tertiary care hospital over a period of 9 months (from April 2019 to December 2019).All patients who underwent microlaryngeal surgery (MLS) during this period were included.Results: There were 89 patients in the study group.There were three types of discrepancies noted.In the first group (5.6% cases), the videostroboscopic diagnosis was found wrong by the examination under anesthesia.In the second group (12.35% cases), the videostroboscopic diagnosis was confirmed by the operation theatre examination but additional lesions within or beside the primary lesion were also noted.Mucosal bridges and sulci were the commonest among them.The third group (5.6%) had lesions on the opposite cord, which were not detected by the office VSS.In the fourth group (94.4% cases) the diagnosis was confirmed with video laryngoscopy in the operating room.Conclusion: Many small lesions of the vocal cords may go unnoticed during the office VSS.While the change in the diagnosis was relatively rare, additional lesions on the ipsilateral and contralateral cords were more frequent.Hence in doubtful cases, examination under anesthesia is an important tool in reaching the correct diagnosis.