Figure 5.

Intramural and extramural observation items of the esophagus. (a) Peri-ECVs. Many blood vessels of small diameter are observed adjacent to the esophageal adventitia (arrow). The existence of these vessels makes the margin of the musculus longitudinalis externus appear unclear. (b) Para-ECVs. Blood vessels with a relatively large diameter located distant to the esophageal adventitia (arrow). (c) Veins perforating the esophageal wall. Perforating veins communicating between the esophageal varices and extramural ECVs (arrow).