The Effect of Sympathectomy, Vagotomy, and Oesophageal Interruption on the Canine Gastro-oesophageal Sphincter

The nature of the control of the gastro-oesophageal sphincter is obscure. It has been thought to be under the regulation of the autonomic nervous system so that through the influences of the vagus and sympathetic nerves the resting tone is maintained and relaxation and contraction are initiated. Beyond this broad generalization, however, there is considerable divergence of opinion as to the precise function of the various nervous elements and their inter-relationships. The purpose of this investigation was to deter-mine the effect of certain nerve and oesophageal interruption procedures on the resting tone of the sphincter and its relaxation and contraction during swallowing. REVIEW OF THE LITERATURE A comprehensive review of the work of previous investigators in this field is given by Ingelfinger (1958) in his treatise on oesophageal motility. Most studies have involved stimulation or destruc-tion of the vagus and sympathetic nerves. The usual methods of observation have been mano-metric estimations and radiological examination. All workers agree that the vagus has some influence in the lower end of the oesophagus. Many believe that the vagus exerts both inhibitory and motor actions on the sphincter, and it has been suggested that these impulses travel by different routes. Openchowski (1889) postulated the existence of a distinct ' dilator cardiac ' nerve in man. This has not been re-identified, but Zeller and Burget (1937) suggested that in the dog inhibitory impulses left the cervical vagus and travelled down the wall of the oesophagus, either by way of vagal fibres or by propagation in the intramural plexus. Support for this concept was provided by Grondahl and Haney (1940) and by 'Recipient of a travelling fellowship from the Wellcome Trust.