FIGURE 3 The esophagus was confined by LIPV, vertebral body, and descending aorta in a triangular space at the LIPV level. In this group, the distance from MPL to the esophagus was shorter than that in the esophagus, unconfined in a triangular space at the LIPV level (Figure 2A). DA, descending aorta; E, esophagus; LA, left atrium; LIPV, left inferior pulmonary vein; VB, vertebral body; MPL, modified posterior-inferior line.