Histological study of the structural layers around the esophagus in the lower mediastinum

Table 1 Definitions of thoracic esophagus and lower mediastinal lymph nodes

Definitions of the thoracic esophagus
Upper thoracic esophagus (Ut)	From the sternal notch to the tracheal bifurcation
Middle thoracic esophagus (Mt)	The proximal half of the two equal portions between the tracheal bifurcation and the esophagogastric junction
Lower thoracic esophagus (Lt)	The thoracic part of the distal half of the two equal portions between the tracheal bifurcation and the esophagogastric junction
Definitions of lower mediastinal lymph nodes
No. 110	Lower thoracic paraesophageal lymph nodes
No. 111	Supradiaphragmatic lymph nodes
No. 112aoA	Anterior thoracic paraaortic lymph nodes
No. 112aoP	Posterior thoracic paraaortic lymph nodes
No. 112pul	Pulmonary ligament lymph nodes

Table 2 Distribution of lymph nodes

Cadaver No.	Para-esophageal area	Intermediate area				Para-aortic area
		Ventral	Lateral-right	Lateral-left	Dorsal
1	3	0	1	2	0	1
2	3	1	1	3	0	2
3	1	1	1	1	1	1
4	2	0	2	1	2	2
5	1	1	0	0	2	1
6	0	1	0	1	0	2
7	1	2	2	0	0	0
Average	1.6	0.9	1	1.1	0.7	1.3

Figures of the leftmost column indicate the cadaver numbers. Other figures indicate the number of lymph nodes in each area.

Table 3 Thickness of the dorsal part of the intermediate area

Cadaver No.	Cranial side (μm)	Caudal side (μm)
1	289.7	1002.7
2	895.2	2337.9
3	928.6	3427.8
4	1573.6	3441.6
7	927.3	2688.9
Average (μm)	742.4	2070.2

Figures of the leftmost column indicate the cadaver numbers. Other figures indicate the distance between the aorta and esophagus.