Distribution of Lymphatic Vessels in the Neural Plexuses Surrounding the Superior Mesenteric Artery

Abstract

To investigate whether lymphatic vessels exist in the neural plexuses surrounding the superior mesenteric artery (SMA) and the ultrastructural relationship between neural plexuses and lymphatic vessels.

A total of 970 serial sections including the structure surrounding the SMA were obtained from 9 cadavers. They were subjected to conventional hematoxylin/eosin staining and immunostaining for the lymphatic marker D2-40. Epithelial membrane antigen and S100 were also immunostained to identify the perineurium and nerve bundles, respectively.

Thin-walled, erythrocyte-free vessels staining with lymphatic markers (D2-40) were found in the neural plexuses surrounding the SMA along a full circumference. There seemed to be a distribution correlation between lymphatic vessels and neural plexuses. Lymphatic vessels were not identified within the nerve bundles. The plexuses contained no lymph nodes in any sections.

To our knowledge we report the immunohistochemical visualization of lymphatic vessels in peri-SMA neural plexuses for the first time. Therefore, particular attention should be paid to the lymphatic vessels within neural plexuses as a possible route of invasion and the source of pancreatic cancer recurrence.