Blood Vessels in Ganglia in Human Esophagus Might Explain the Higher Frequency of Megaesophagus Compared with Megacolon

This study aimed to determine the existence of blood vessels within ganglia of the myenteric plexus of the human esophagus and colon. At necropsy, 15 stillborns, newborns and children up to two years of age, with no gastrointestinal disorders, were examined. Rings of the esophagus and colon were analyzed and then fixed in formalin and processed for paraffin. Histological sections were stained by hematoxylin-eosin, Giemsa and immunohistochemistry for the characterization of endothelial cells, using antibodies for anti-factor VIII and CD31. Blood vessels were identified within the ganglia of the myenteric plexus of the esophagus, and no blood vessels were found in any ganglia of the colon. It was concluded that the ganglia of the myenteric plexus of the esophagus are vascularized, while the ganglia of the colon are avascular. Vascularization within the esophageal ganglia could facilitate the entrance of infectious agents, as well as the development of inflammatory responses (ganglionitis) and denervation, as found in Chagas disease and idiopathic achalasia. This could explain the higher frequency of megaesophagus compared with megacolon.