Endosonographic Anatomy Of The Mediastinum

The esophagus presents an excellent window for visualization of surrounding structures in the mediastinum. present nomenclature divides the mediastinum into three parts: the upper section (upper esophageal sphincter to aortic arch), middle (aortic arch to subcarinal region, just distal to the azy-gos vein), and lower (subcarinal region to cardia). Figure 3 demonstrates paraesophageal structures and organs. The trachea is seen only as an air column; thus its wall cannot be delineated. Lymph nodes may be visible along the length of the esophagus, even in normal individuals. They may be especially pronounced in the subcarinal region. peri-aortic tissue is seen alongside the distal esophagus.

Lymph nodes can be identified in the posterior mediastinum, retroperitoneum, and celiac regions. posterior mediastinal lymph nodes are predominantly left-sided and communicate with the para-aortic lymph nodes of the abdomen; hence thorough evaluation of the celiac region is important. Additionally, metastases may be seen in the left adrenal gland and left lobe of the liver. Corresponding to the American Thoracic Society's mediastinal map for lymphadenopathy (Fig. 4), stations visible to EUS include the following: subcarinal (station 7); subaortic (station 5); paraesophageal (station 8); inferior pulmonary ligament region (station 9); and main bronchial (station 10). Lymph nodes in the left paratracheal (station 2) and left lower paratracheal (station 4) stations can be imaged and sampled, whereas the right paratracheal stations are inaccessible owing to air interference from the trachea. stations removed from the esophagus, i.e., lobar (station 12), interlobar (station 11), and those anterior and lateral to the trachea (stations 3 and 6)

Fig. 1. 360° circular plane endosonographic image of the mediastinum. „. „ _ , , . . .. ,

Fig. 3. Paraesophageal structures as seen by endosonographic evaluation.

Fig. 1. 360° circular plane endosonographic image of the mediastinum. „. „ _ , , . . .. ,

Fig. 3. Paraesophageal structures as seen by endosonographic evaluation.

Fig. 4. American Thoracic Society mediastinal map of lymph node stations.

Fig. 2. Representative computed tomography image of the mediastinum.

cannot be imaged with EUS, but may be accessible to new endobronchial ultrasound technologies.

Was this article helpful?

0 0

Post a comment