Analysis of eustachian tube function by video endoscopy

Abstract

Objective: Human eustachian tubes (ET) were inspected in vivo endoscopically, and video recordings were made for careful slow-motion analysis of normal physiologic function.

Setting: Ambulatory office in a tertiary referral center.

Subjects: Thirty-four adults, 17 with no history of ET dysfunction (2 of whom had tympanic membrane perforations), 17 with known ET dysfunction.

Interventions: Transnasal endoscopic examination of the nasopharyngeal opening of the eustachian tube during rest, swallowing, and yawning.

Main outcome measures: Video analysis of ET opening movements.

Results: Normal ETs had four consistent sequential movements: (1) palatal elevation causing passive, then active, rotation of the medial cartilaginous lamina; (2) lateral excursion of the lateral pharyngeal wall; (3) dilation of the lumen, caused primarily by tensor veli palatini muscle movement beginning distally and inferiorly, then opening proximally and superiorly; and (4) opening of the tubal valve at the isthmus caused by dilator tubae muscle contraction. Dysfunctional ETs had intraluminal edema, polyps, or minimal muscle movement.

Conclusions: Slow-motion endoscopic video analysis may be a useful new technique for the study of eustachian tube physiology. Consistent muscle movement patterns were demonstrated in normal subjects but were absent in abnormal subjects. More studies of normal and abnormal patterns are needed to establish useful clinical correlates.