Anatomic Profiles Related to Transesophageal Echocardiographic Probe Insertion: A Retrospective Computed Tomographic...

To clarify the anatomic relationship between the larynx and the esophageal inlet relevant to transesophageal echocardiography (TEE) and to identify structural factors associated with probe-related injury.

A retrospective observational study based on computed tomography (CT).

A single center in Japan.

A total of 180 consecutive patients who underwent intraoperative TEE between 2023 and 2025 and had preoperative CT, including the cervical region.

None. CT images were reviewed to determine the inlet orientation angle and the minimal distance between the cricoid cartilage and vertebral body (retrocricoid space).

The inlet orientation ranged from -17.8° to +33.3° (mean, +2.9°). A posterior inlet was identified in 179 of 180 patients (99.4%), with 1 posterolateral and no lateral orientation. The retrocricoid space measured 1.4 to 13.4 mm (mean, 6.3 mm) and was narrower than the shaft diameter of a TEE probe (<10 mm) in most patients. Additional CT findings included calcification of the posterior cricoid lamina (7.8%), unilateral vertebral protrusion (3.3%), and spinous bony projections (2.8%). These data indicate that the inlet is almost always posterior. A narrow retrocricoid space or rigid posterior structure may increase local wall stress during blind insertion.

CT imaging has demonstrated that the esophageal inlet lies posterior to the larynx in nearly all patients. When resistance is encountered, the probe should be advanced along a slightly oblique 5- or 7-o'clock trajectory with gentle rotation and anteflexion. These findings provide an anatomic basis for standardized TEE training and injury prevention.