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Updated: Feb 14, 2026

Discovering Middle Ear Anatomy by Transcanal Endoscopic Ear Surgery: A Dissection Manual
Published on: January 11, 2018
The anatomic applicability of transcanal endoscopic ear surgery in children
Wan-Hsuan Sun1, Chin-Lung Kuo2, Tzu-Chin Huang1
1Department of Otolaryngology, Cathay General Hospital, Taipei, Taiwan.
Objective:
The feasibility of TEES in dealing with pediatric middle ear disease is still under investigation. The goal of this study was to compare anatomical dimensions of the EAC between children and adults, and to analyze the anatomic applicability of TEES in children.
Methods:
Forty pediatric (18 years old and younger) and 20 adult patients who received TB-HRCT to evaluate middle ear conditions were enrolled from December 2010 to December 2015. Dimensions including the diameters of the EAC orifice, isthmus and tympanic membrane annulus, the length of EAC, the height of the middle ear, and the angle between tympanic membrane and EAC axis were determined according to the TB-HRCT data.
Results:
The diameters of the EAC orifice and isthmus and length of EAC in the pediatric patients were slightly smaller than those in the adult patients. The anatomical dimensions of middle ear were similar in both groups. Simple regression analysis indicated that the diameters of the EAC orifice and isthmus and the length of the EAC were positively correlated with the age of the pediatric patients. In the pediatric patients, 67 ears (83.75%) had an EAC isthmus diameter larger than 4 mm and are sufficient with a 3-mm endoscope manipulation.
Conclusion:
TEES is applicable for most pediatric patients using an endoscope with a diameter of 3 mm or smaller. With an appropriate endoscope and instruments, TEES is a safe and effective alternative to treat pediatric middle ear disease.
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