This peculiar form of ulcer is met with only in the stomach, first part of the duodenum, and lower part of (esophagus. The duodenum is not an infrequent seat, the oesophagus a more unusual one. It is also called, sometimes, the Round, the Chronic, and the Perforating ulcer. It is clear from the localities in which it occurs that its peculiarities are due to the action'of the gastric juice.
The ulcer is usually round or oval in shape, and presents the appearance as if a conical piece of the wall of the stomach had been punched out from within, its edges being perfectly defined without any considerable thickening of the neighbouring mucous membrane, and the floor of the ulcer perfectly clean (see Fig. 390). The superficial extent and depth of the ulcer vary considerably. The commonest size is about that of a shilling, but this may be exceeded considerably, and Cruveilhier has described an ulcer which was 6 1/2 inches long and 3 1/2 inches broad. In the smaller ulcers the floor is formed of the coats of the stomach, probably with some new-formed connective tissue. In the larger and deeper ones the tissue of neighbouring organs may be exposed, such as that of the pancreas or liver. The floor of the ulcer does not present any of the usual appearances of a granulating wound, but is clean and smooth, the actual tissue of the part being exposed, perhaps with some induration from new formation of connective tissue.
The situation of the ulcer is mostly in the neighbourhood of the lesser curvature, and nearer the pyloric than the cardiac orifice. It is more frequent on the posterior than the anterior wall. Although usually single, it is not uncommon to find more than one ulcer present in the same case.
The ulcer presents a tendency to penetrate more and more deeply, from which circumstance it is named the Perforating ulcer. It does not appear to extend circumferentially to any considerable degree; it is probable indeed that at the very first the ulcer assumes its full superficial dimensions. Eating into the wall of the stomach, it may penetrate through the entire coats, and sundry accidents are liable to ensue.
Fig. 390. - Perforating ulcers of stomach open and healed, from the same case. In the upper piece of tissue is a flat slightly depressed cicatrix and some smaller ones near the lower border. The lower piece shows a deeply excavated ulcer, which had caused death hy perforation into the peritoneum.
One of the commonest of these accidents is Haemorrhage. The ulcer penetrates one or more vessels at its base. The vessels may be, small and the haemorrhage not very considerable, but sometimes a considerable artery is laid open, and a serious, even a fatal haemorrhage results. From the commoner situations of the ulcers the arteries most frequently penetrated are these - the coronary artery or one of its branches, the gastro-epiploic, the pancreatic, and the splenic. Sometimes the open mouth of the vessel can be seen, after death, in the floor of the ulcer (see Fig. 391).
Fig. 391. - Perforating ulcer of duodenum opening into gastro-epiploic artery and resulting in fatal haemorrhage. The ulcer, which is quadrilateral in form, is situated immediately beyond the pylorus. The floor is formed in part by the pancreas. A piece of whale-bone has been passed through the artery.
Perforation is another result of the penetration of the ulcer. For the most part, by the time the ulcer has eaten through the wall of the stomach, the latter has already acquired adhesion to some neighbouring structure, and so actual rupture of the stomach and escape of its contents into the peritoneal cavity are not common. The adhesion may be to the liver or pancreas, or, more rarely, to the spleen, diaphragm, colon, abdominal wall. By the extension of the ulcer these structures may be eaten into and their tissue exposed. The tissue when first exposed has its normal appearance, but it usually becomes condensed and cicatricial. Sometimes the irritation of the gastric juice produces suppuration and the formation of an Abscess, especially in the case of penetration into the liver.
Rupture of the stomach results if perforation occur without previous adhesion of the wall. This will happen most readily where the wall of the stomach is liable to shift about during the regular peristaltic movements, and also where there is no solid viscus to which it may readily adhere. Both these conditions are fulfilled in the case of ulcers of the anterior wall, and so it happens that rupture most frequently occurs in this situation. The ulcers which lead to perforation are frequently very small, and the aperture in the serous coat may be as large as the ulcer itself. The result of the rupture is acute peritonitis, which is generally fatal.
The ulcer, when situated at or near the pylorus, may lead to partial Obstruction of the pylorus. This may be due to distortion of the parts and folding of the mucous membrane from shrinking of the ulcer. It will follow most readily in ulcers of the duodenum immediately beyond the sphincter. This situation is not uncommon, and the ulcer not infrequently partly involves the edge of the pylorus. In a case observed by the author the symptoms during life and even the appearances after death strongly suggested cancer of the pylorus.
Healing of the perforating ulcer is by no means an unusual occurrence. In the experiments to be referred to presently, in which ulcers were produced artificially in animals, they healed very readily. In man also they are frequently recovered from, and we often meet with cicatrices in the stomach. The cicatrices are usually flat, as in Fig. 390, and there may even be no very obvious cicatrix at all. The author met with a case in which three weeks after a very severe haemorrhage, presumably from an ulcer of the stomach, only an obscure cicatrix could be found. In order to healing, the acrid condition of the gastric juice, which seems to be the chief agent in their causation, must be corrected.
The mode of origin of these ulcers is a matter of some difficulty. It is obvious, from the shape and appearance of the ulcer, that it has arisen by the necrosis and subsequent digestion of a piece of the wall of the stomach. The funnel-shaped outline of the ulcer suggested to Virchow that the necrosis occurred by obstruction or interference with an arterial branch, and he observed as confirmatory of this that the ulcers most frequently had their seat at the point of entrance of arterial branches into the wall of the stomach. The experiments of Panum and Cohnheim confirm this view in so far as they show that ulcersmay be produced by embolism of the arteries of the stomach. The perforating ulcer, however, is not met with specially in cases of embolism or thrombosis of the arteries of the stomach, but in the immense majority of instances in cases where no such disturbance of the circulation exists. It has been suggested again that a venous hyperemia, by causing stagnation and even haemorrhage (see afterwards) in defined areas of the mucous membrane, may produce such weakening of the tissue as to induce necrosis and digestion of it.
In most cases of gastric ulcer there is serious and usually prolonged Dyspepsia, and the persons are frequently anaemic. Some abnormal condition of the gastric juice, by virtue of which it is peculiarly irritating to the mucous membrane, seems to be an essential factor, while a weakened condition of the mucous membrane is also of consequence. In most cases the gastric juice is abnormally acid, and it has been thought that by neutralizing the natural alkalinity of the tissues it may lead to their necrosis.
On the whole it seems probable that an acrid gastric juice, taking advantage of any accidental stagnation in a defined area of the mucous membrane, may lead to its necrosis and the formation of the ulcer.
The frequency of ulcer of the stomach may be judged of from the fact that, according to the results of post-mortem examinations, it is said that there are ulcers or cicatrices in about one in twenty of the cases examined after death.
Baillie, Morb. Anat., 3rd ed., 1812; Brinton, Ulcer of stom., 1857; Virchow, Arch., v.; Muller, Geschwiir des Magens, 1860; Panum, Virch. Arch., xxv.; Cohnheim, Allg. Path., ii.; Klebs, Handb., i.; Leube, in Ziemssen's Encycl., I.c.; Hauser, Das Magengeschwur, sein Vernarbungsproc, 1883; Fenwick, Jour, of Path. and Bact., vol. i., 1893, p. 417; Leith, Edin. Hosp. Bep., vol. ii.