Measurements of The Pediatric Cartilaginous Eustachian Tube: Implications for Balloon Dilation

Abstract

Objectives: (1) Measure the cartilaginous Eustachian tube (ET) length using a computed tomography (CT) scan and (2) develop a prediction model to measure this length without the need of a CT scan.Study Design: CT measurements in children.Setting: Children's Hospital. Methods: CT scans were reformatted to project the cranial and caudal limits of the cartilaginous ET. The length was measured in 193 children who underwent a neck CT scan for nonotologic indications. Five physicians independently reviewed all or some of these measures. Four different models based on age, age ranges, weight, and height were created and compared to predict ET length.Results: The cartilaginous ET length was 25.3 AE 3.1 mm for the right and for the left ear. The mean ET length for the females was statistically significantly less than the length in males. The lower ET lengths in children as old as 5 years of age were less than the 2 cm adult criteria used for catheter insertion. All 4 models performed equally well in predicting ET length. Model number 4, which is based on height, was the easiest to calculate ET length. Conclusion:The cartilaginous portion of the pediatric ET can be measured with good precision using reformatted CT images. We caution against using the "adult" criteria of 2 cm for catheter insertion in children, especially those younger than 5 years of age. We recommend using a model utilizing height measures to estimate ET length or direct measurements from a reformatted CT scan.

Age‐related morphological change in bony segment and cartilage segment of Eustachian tube

“…Balloon dilation of the Eustachian tube (BDET) was increasingly applied in adults and children as an effective option for chronic otitis media 4,20 . Previous studies have focused on the different lengths of the cartilaginous segment of the ET in children and adults 5–9 . In addition to the short length of the ET, the position of ET's cartilage segment was flat and close to the horizontal plane in childhood.…”

“…4,20 Previous studies have focused on the different lengths of the cartilaginous segment of the ET in children and adults. [5][6][7][8][9] In addition to the short length of the ET, the position of ET's cartilage segment was flat and close to the horizontal plane in childhood. The cartilage segment of the ET gradually bent close to the sagittal plane and away from the horizontal plane from birth to adulthood.…”

“…It was reported the possible injury to the adjacent middle or inner ear and the carotid artery presents with bleeding, hearing loss and patulous Eustachian tubes. 7 , 8 , 9 …”

“…However, due to the angular and length changes of the cartilage and bony segments of ET in space with age, the potential risks lie in inaccurate evaluation the difference in the dimension and position of ET between children and adults in BDET. It was reported the possible injury to the adjacent middle or inner ear and the carotid artery presents with bleeding, hearing loss and patulous Eustachian tubes 7–9 …”

“…It was reported the possible injury to the adjacent middle or inner ear and the carotid artery presents with bleeding, hearing loss and patulous Eustachian tubes. [7][8][9] The Eustachian tube is composed of a bony segment and a cartilage segment. The ET antero-inferiorly extended the cartilage segment to the nasopharynx.…”