ANATOMY OF THE EXTRINSIC NERVE SUPPLY OF THE ESOPHAGUS IN ESOPHAGEAL ATRESIA OF THE COMMON TYPE

Cadaver dissections of the oesophagus were carried out to evaluate its extrinsic nerve supply in oesophageal atresia (OA) with distal trache o-oesophageal fistula. In OA the atresia occurs at an anatomic watersh ed in the oesophagus. Proximal to the atresia, the oesophageal wall co ntains striated muscle. There is a known change in the type of muscle that forms the oesophagus as it descends through the chest. As a conti nuation of the pharynx, its wall is made up entirely of striated muscl e, which is gradually replaced by smooth muscle. What percentage of th e wall proximal to an atresia is normally striated is not known. Dista l to the atresia the oesophagus is a smooth-muscle tube that receives its extrinsic motor nerve supply from the vagal nerves. These specific nerve fibres have their central origin in the dorsal nucleus of the v agus and are part of the autonomic nervous system. They appear to reac h the oesophagus with its blood supply in an ordered but random manner . As the autonomic nervous system does not supply striated muscles, fi bres of the vagal nerves that supply the proximal pouch must be somati c nerves. This is confirmed, as this portion of the oesophagus is show n to be supplied by the recurrent laryngeal. nerves, which contain fib res that have their origin in the nucleus ambiguous. These nerves are bilateral and reach the oesophageal wall in a segmental fashion; this supply is continuous with that of the pharynx. As the oesophagus proxi mal to an atresia anatomically belongs to the pharynx, it is called th e pharyngeal oesophagus. For a similar reason, the distal segment is n amed the gastric oesophagus. This anatomy is of practical importance t o the surgeon.