Upon auscultation over a dilated stomach sometimes a fine crackling or sizzling sound, like that audible upon first uncorking a bottle of soda-water, can be heard.21 This is referable to the fermentation which is in progress in the stomach. Eichhorst says that a similar but finer crackling sound can be heard over a stomach in which carbonic acid gas is being artificially generated, and that this sound abruptly ceases when the ear passes below the limits of the greater curvature.22
21 Pauli was the first to record this phenomenon (De Ventriculi Dilatatione, Frankfurt, 1839).
22 Handb. d. spec. Path. u. Ther., Bd. i. p. 750, 1883.
The displacement of neighboring organs by a dilated stomach does not generally give rise to important physical signs. As the tendency of a dilated stomach is to sink down in the abdomen, there is not usually much displacement of the thoracic viscera. If, however, the fundus of the stomach be distended with gas, the heart may be pushed upward, and, being pressed against the chest-wall, its apex-beat may be more forcible and diffused than normal. The tympanitic stomach may impart a metallic quality to the cardiac sounds.
MORBID ANATOMY.—Considerable degrees of dilatation of the stomach are easily recognized by post-mortem examination. In extreme cases the stomach occupies all of the anterior region of the abdomen, covering over the intestines and extending down to the pubes or even into the true pelvis. Many cases are recorded in which the stomach was capable of holding six to twelve pints. Godon23 describes under the name ventriculi hydrops a hardly credible case in which it is said that the stomach contained ninety pounds of fluid! In the ordinary cases of gastrectasia the lower border of the stomach is found somewhere between the umbilicus and the pubes, frequently about a hand's breadth below the level of the umbilicus.
23 Diss. de Hydrops Ventriculi, London, 1646. This celebrated case is described with much detail. For three years the abdomen was enormously distended, but the patient, a woman, never vomited. The affection was supposed to be dropsy of the peritoneum. Death occurred in a condition of extreme marasmus. The pylorus was the seat of a hydatid cyst which extended into the duodenum. The stomach, which was enormously distended, contained ninety pounds of fluid, in which floated a great number of hydatid cysts, some of which were ruptured. The anterior wall of the stomach was adherent to the parietal peritoneum. The two orifices of the stomach were drawn close to each other. The length of the stomach equalled a Paris ell.
The fundus, being the most dilatable part of the stomach, is in most cases disproportionately dilated in comparison with the pyloric region. This excessive dilatation of the fundus is most noticeable in gastrectasia due to stenosis. In most cases of dilatation the pylorus sinks down somewhat in the abdomen, but in consequence of the distension of the lower segment of the stomach the long axis of the organ is more nearly transverse than normal. If the pylorus be fixed, the lesser curvature may be drawn down in its middle so as to acquire a hooked shape. The lesser curvature, which should be covered by the liver, may be found considerably below its normal level. The dilated fundus may extend from the left hypochondrium into the left iliac region.24
24 Fogt reports a case in which an enormously dilated stomach occupied a scrotal hernia of the left side. He refers to two other similar cases (Aerztl. Intelligenzbl., 1884, No. 26).
More or less dilatation of the oesophagus is associated with marked dilatation of the stomach. If dilatation of the stomach be due to obstruction in the upper part of the intestine, then the pyloric orifice and the intestine on the proximal side of the obstruction will be found dilated.
The walls of a dilated stomach may be hypertrophied, and such cases are called hypertrophic dilatation; or the walls may be of normal thickness or may be thinned, and these cases are called atrophic or atonic dilatation. In general, the thickness of the gastric walls in gastrectasia depends upon that of the muscular coat. As a rule, in cases of pyloric stenosis the muscular coat of the stomach is hypertrophied. This hypertrophy affects chiefly the muscle of the pyloric region. The gastric walls in stenotic dilatation may, however, be of normal thickness or even atrophied. In non-stenotic dilatation the muscular coat may be either hypertrophied or atrophied, but it rarely attains the thickness observed in cases of gastrectasia due to obstruction. Maier and others have repeatedly observed fatty and colloid degeneration of the muscular fibres of dilated stomachs.25 More frequently, however, no degenerative change has been found in the muscle.