The gastro-oesophageal junction in infancy; a combined cineradiographic and manometric study.

Intragastric and intra-oesophageal pressures were recorded using water-filled "polythene " tubes of 2.5 mm. external diameter connected to an electromanometer of the capacitance type (N.E.P. Ltd.) and a two-channel direct writing pen recorder (Sanborn " twin-viso cardiette "). The recording end of each tube had a side hole about 1 cm. from the tip, the latter being closed off. The position of the recording hole was indicated by a radio-opaque marker of known dimensions. Cineradiography with image intensification and intermittent radiation was used as described for cineangiocardiography (Astley, 1955; Astley and Oldham, 1956). Examinations were carried out at 16 frames per second. The precise instant of each picture was indicated below the pressure tracing on the second channel of the pen recorder. The procedure used was, with few modifications, identical to that employed in the study of adults (Botha et al., 1957). No local nasopharyngeal anaesthesia was used because of the danger of subsequent inhalation and also because it would have been impossible to prevent these small infants swallowing the local anaesthetic agent. To obtain recordings free from extraneous artefacts caused by crying and breath holding, all infants studied were given chloral hydrate. The aim was to induce no more than a somnolent state sufficient only to permit the withdrawal of the recording end of the "polythene" tube across the gastro-oesophageal junction under conditions of relaxation and quiet, regular breathing. The recording tube was passed through the nose into the stomach and the infant rotated slightly into