ANATOMY OF THE EUSTACHIAN-TUBE AS DEMONSTRATED BY ENDOLUMINAL ULTRASONOGRAPHY

Using a new application of the endoluminal approach, we were able to d emonstrate the sonographic anatomy of the eustachian tube in vitro and in vivo and correlate it with the plastic-embedded specimen. Five adu lt normocephalic cadavers, two patients, and one specimen especially p repared for embedding in plastic were examined. A specifically develop ed device was used to insert the ultrasound transducer employing an en do-oral approach. The investigation was performed using an intravascul ar ultrasound unit. In all cases the tube could be visualized in its e ntirety and relevant anatomic structures identified and compared with the specimen at the corresponding levels. The deeper layers, including the paratubal structures and the mucosa, could be distinguished for t he first time by means of endoluminal ultrasonography. Now that endolu minal ultrasonography has revealed this anatomic information, further studies will be able to gauge the clinical efficacy of our method in c ases of ventilatory, drainage, and clearance problems. The images show ed no difference between the structures in vitro and in vivo, and the in vivo examination was even easier than the in vitro one owing to bet ter tissue turgor.