Radiological Anatomy of Eustachian Tube and its Correlation with Graft Uptake in Type I Tympanoplasty

Abstract

Introduction: Eustachian tube (ET) also known as pharyngotympanic tube connects nasopharynx with the middle ear. Evaluation of ET anatomy is aimed in patients with chronic otitis media. Materials and Methods: In a study of 53 patients, HRCT Temporal bone was done on 128 dual source simens somatom definition flash machine on 5mm cut section and tympanoplasty was carried out. Results: ET angle is one of the important factors for middle ear aeration. Outcome of tympanoplasty at 12th week was 88.7%. In the patients with vertical Eustachian Tube (i.e., more Eustachian Tube angle with the horizontal plane), better graft uptake in tympanoplasty was observed which was statistically significant. However, graft uptake did not correlate with the length of the Eustachian tube. Conclusion: It was concluded that on measuring ET length on HRCT, majority of the patients had bony length of 10-12 mm, cartilaginous length of 15-19 mm and total ET length of 28-32 mm. Majority of the patients had ET angle of 21-30 degrees with the hard palate.