Published online Jan 28, 2019. doi: 10.3748/wjg.v25.i4.498
Peer-review started: September 30, 2018
First decision: November 15, 2018
Revised: December 3, 2018
Accepted: December 19, 2018
Article in press: December 20, 2018
Published online: January 28, 2019
To characterize esophageal endoluminal landmarks to permit radial and longitudinal esophageal orientation and accurate lesion location.
Distance from the incisors and radial orientation were estimated for the main left bronchus and the left atrium landmarks in 207 consecutive patients using white light examination. A sub-study was also performed using white light followed by endoscopic ultrasound (EUS) in 25 consecutive patients to confirm the findings. The scope orientation throughout the exam was maintained at the natural axis, where the left esophageal quadrant corresponds to the area between 6 and 9 o’clock. When an anatomical landmark was identified, it was recorded with a photograph and its quadrant orientation and distance from the incisors were determined. The reference points to obtain the distances and radial orientation were as follows: the midpoint of the left main bronchus and the most intense pulsatile zone of the left atrium. With the video processor system set to moderate insufflation, measurements were obtained at the end of the patients’ air expiration.
The left main bronchus and left atrium esophageal landmarks were identified using white light in 99% and 100% of subjects at a mean distance of 25.8 cm (SD 2.3), and 31.4 cm (SD 2.4) from the incisors, respectively. The left main bronchus landmark was found to be a tubular, concave, non-pulsatile, esophageal external compression, occupying approximately 1/4 of the circumference. The left atrium landmark was identified as a round, convex, pulsatile, esophageal external compression, occupying approximately 1/4 of the circumference. Both landmarks were identified using white light on the anterior esophageal quadrant. In the sub-study, the left main bronchus was identified in 24 (92%) patients at 25.4 cm (SD 2.1) and 26.7 cm (SD 1.9) from the incisors, by white light and EUS, respectively. The left atrium was recognized in all patients at 30.5 cm (SD 1.9), and 31.6 cm (SD 2.3) from the incisors, by both white light and EUS, respectively. EUS confirmed that the landmarks corresponded to these two structures, respectively, and that they were located on the anterior esophageal wall. The Bland-Altman plot demonstrated high agreement between the white light and EUS measurements.
This study provides an endoscopic characterization of esophageal landmarks corresponding to the left main bronchus and left atrium, to permit radial and longitudinal orientation and accurate lesion location.
Core tip: Although accurate photo documentation of endoscopic landmarks and a careful description of the location of an esophageal lesion are included in endoscopy quality guidelines, clinical practice lacks these essentials. This study characterized two esophageal landmarks to permit radial and longitudinal orientation and accurate lesion location. The left main bronchus and left atrium landmarks were identified in 99% and 100% of patients on the anterior esophageal quadrant and at a mean distance of 25.8 cm and 31.4 cm from the incisors, respectively. The endoscopic ultrasound sub-study confirmed these findings and the anterior orientation of the landmarks.