25 Deutsches Archiv f. klin. Med., Bd. vi. p. 480; Landerer, op. cit. Maier designates as colloid degeneration a peculiar homogeneous, glistening appearance of the muscular fibres. This change is not such as would usually be called colloid, but this term is loosely used to designate a great variety of pathological changes. The form of muscular hypertrophy in gastrectasia is chiefly the numerical.
The mucous membrane in dilatation of the stomach is usually in the condition of chronic catarrhal gastritis. Although there are various statements as to atrophy of the gastric tubules and degeneration of the epithelial cells in the tubes in cases of gastric dilatation, satisfactory histological investigations of the mucous membrane of the stomach in this disease are wanting.26
26 For satisfactory studies of this nature it is desirable that alcohol or some preservative fluid should be injected into the stomach immediately after death.
Atrophy of various abdominal viscera—particularly of the spleen, which is usually small in this disease—has been attributed to the pressure of a dilated stomach. This atrophy, however, is probably in many cases only a part of the general emaciation and anæmia.
While well-marked cases of dilatation of the stomach cannot be mistaken on post-mortem examination, it is important to add that the pathological anatomist cannot always decide whether or not dilatation of the stomach exists in the clinical sense. The following considerations will make this evident: In the first place, the stomach is a very variable organ as regards its size, so that it is impossible to set definite limits, and say that a stomach exceeding these is necessarily dilated, while a stomach not exceeding these limits is normal. In the second place, it belongs to the clinical definition of dilatation of the stomach that the organ is insufficient for the performance of its normal functions. This insufficiency cannot be determined at the post-mortem table. To determine, therefore, whether stomachs which fall within certain not easily definable limits of size are pathologically dilated or not, it is necessary to correct and complete the results of the post-mortem examination by a knowledge of the clinical history.27
27 To deny all value to post-mortem examination in the determination of dilatation of the stomach, as has been done, is absurd. In the majority of cases this examination affords satisfactory evidence, but for some cases a reservation like that in the text must be made. Rosenbach in an able article shows the error of regarding dilatation of the stomach too exclusively from the anatomical point of view ("Der Mechanismus und die Diagnose der Mageninsufficienz," Volkmann's Samml. klin. Vorträge, No. 153).
DIAGNOSIS.—A considerable degree of dilatation of the stomach can generally be diagnosticated without difficulty by means of the symptoms and physical signs which have been described. The most important diagnostic features relate to the character of the vomiting and to the physical signs, together with the information afforded by the use of the stomach-tube. The diagnostic characters of the vomiting are the large quantity rejected, its occurrence several hours after a meal, its periodicity with long intervals, the temporary relief afforded, the presence of undigested food taken a considerable time previously, and the existence of fermentation. Washing out the stomach will also afford evidence of stagnation of food. The time generally occupied in the digestion of an ordinary meal is not over six to seven hours, so that in health the contents of the stomach removed by the stomach-tube at the end of this time should usually be free from undigested food. There are of course individual idiosyncrasies with reference to the time occupied in digestion, so that implicit reliance cannot be placed on this diagnostic test. Delayed digestion is in itself no evidence of the existence of dilatation, but the establishment of the presence of this symptom may confirm other points in the diagnosis.
Simple inspection, palpation, and percussion of the abdomen are sometimes, although rarely, sufficient for the diagnosis of dilatation of the stomach. Various devices have already been described which aid in the physical examination of the stomach, such as the administration of effervescing powders, the introduction of the stomach-tube, and Piorry's and Penzoldt's methods of determining the lower border of the stomach.28 It is not necessary to repeat here the diagnostic evidence afforded by physical examination. Excellent service as these devices often perform, it must be confessed that they do not always answer the purpose intended. The artificial distension of the stomach with gas does not enable us always to distinguish intestine from stomach. If the abdominal walls are thick or very rigid, this method, like most of the others, is of little or no assistance. Then, as already mentioned, the administration of the powders may fail to produce any distension of the stomach, and may possibly mislead by causing distension of intestine. Moreover, the artificial tympanites may cause the patient much discomfort. The method of determining the lower border of the stomach by Piorry's or Penzoldt's method is not always conclusive. If the stomach be much dilated, it may take a very large quantity of water to produce an appreciable zone of dulness. If the transverse colon be distended with feces, it will not be easy to separate the dulness of the stomach from that of the colon. Moreover, loops of intestine containing feces or gas may lie over the anterior surface of the stomach. The use of the stomach-tube simply for diagnostic purposes is, for various reasons, not always practicable. With due recognition of the important additions during the last few years to our means of exploring the stomach, it must be admitted that we are still far from any positive and universally applicable method of determining the size and position of this organ during life. This admission is the more necessary in view of the extravagant claims which have been made for various more or less complicated contrivances for physical exploration of the stomach.
28 Several other methods have been suggested for determining the size and position of the stomach, but they have not found general acceptance. Thus, Schreiber attaches a soft rubber balloon to the end of a stomach-tube, and after its insertion in the stomach inflates it (Deutsches Arch. f. kl. Med., Bd. 19). In Neubauer's method the long end of a syphon-tube communicating with the stomach is bent upward, and a glass tube is placed in the bent portion. The fluid will evidently stand at the same level in the tube as in the stomach in case the atmospheric pressure in both is the same. The atmospheric pressure in the stomach is produced by using a double tube or by passing a second tube into the stomach (Prager med. Wochenschr., 1879). Purjesz attached a manometer to a stomach-tube, and thought that he could fix the position of the cardia by noting the moment when in the passage downward of the tube the negative pressure changed to positive, but Schreiber has shown that the manometer may indicate negative pressure even after the tube has entered the stomach (Deutsches Arch. f. kl. Med., Bd. 33, p. 425). It has been asserted that by means of auscultatory percussion of a stomach artificially distended with gas the boundaries of the organ can be determined. Leichtenstern considers the metallic quality of the tone heard over the stomach under these circumstances more or less characteristic, while Skamper compares the characteristic tone to that produced by tapping with the finger on the dorsal surface of the hand of which the valar surface is placed against the external ear (Inaug. Diss., Berlin, 1879, p. 30). It has been claimed that the sound as of water dropping into a large cavity, which can be heard when the patient is drinking, can no longer be heard when the auscultating ear passes beyond the greater curvature (V. Bamberger). Wunderlich suggests the possibility of feeling the arteries of the greater curvature through the abdominal walls. Ferber calls attention in cases of gastrectasia to a strip of dulness, with absent vocal and respiratory sounds, corresponding to the posterior inferior border of the left lung. This dulness, which is produced by material in the most dependent part of the dilated stomach, disappears when the patient assumes the knee-elbow position (Deutsche Zeitschr. f. prakt. Med., 1876, No. 42). When it is impossible by other methods to distinguish the lower portion of the stomach from the transverse colon, it has been proposed to distend the colon with water, with gas, or with air injected through a tube passed into the rectum. Penzoldt (op. cit.) found that the length of a tube (hard) or bougie reaching the bottom of the stomach, estimating from the upper incisor teeth, should be in a normal stomach at least 5 cm. less than that of the vertebral column (occiput to coccyx), and at the most not much more than one-third of the length of the body (1:2.8-1:3.3). In three cases of gastrectasia he found the length of the tube inserted into the stomach considerably more than one-third of the length of the body (1:2.4); in one of the cases this length even exceeded that of the vertebral column, and in the others it nearly equalled the length of the vertebral column. Rosenbach's method of determining the elastic and contractile power of the stomach is ingenious, but hardly of practical utility. By injecting air into the stomach through a bulb apparatus attached to the end of a stomach-tube, he is able to tell when the point of the tube passes beneath the surface of fluid in the stomach by hearing on auscultation a characteristic moist bubbling sound. Elevation or depression of the level of the fluid can be determined by withdrawing or by pushing forward the tube. That quantity of fluid which, introduced into an empty stomach, causes no elevation, or perhaps causes a depression, of the level of the food in the stomach, indicates the utmost limit of the elastic and contractile forces of the stomach (Rosenbach, Volkmann's Samml. klin. Vorträge, No. 153).
The determination of the position of the lower border of the stomach does not in itself enable us to infer positively the size of the organ. It may be taken as a general rule that if the lower border of the stomach be found persistently below the level of the umbilicus, the stomach is dilated; but there are many exceptions to this rule. Sometimes an otherwise normal stomach preserves in adult life the vertical position which it had in the foetus, so that its lowest point may be below the umbilicus. According to Kussmaul, a vertical position of the stomach is a predisposing cause of dilatation. Occasionally a stomach has a looped shape, so that without any dilatation of the organ the lowest point may fall below the level of the umbilicus. It is, moreover, a clinical fact established by the experience of many observers that the lower border of the stomach may be found below the level of the umbilicus without the existence of any symptoms of dilatation.