Although dilatation of the stomach has been recognised for centuries as a pathological entity, its full importance was not appreciated until the latter fourth of the nineteenth century, when Kussmaul and his pupils began to consider the effects of obstruction on the functions of digestion.
The causes of mechanical dilatation of the stomach are usually at or near the pylorus or in the duodenum, and may be due to malignant or non-malignant disease. They are :
(a) Cancer of the pylorus.
(b) Cancer of the duodenum.
(c) Rarely sarcoma of the pylorus or duodenum.
(d) Cancer of the body of the stomach leading to hour-glass stricture and dilatation of the cardiac portion of the stomach.
Other causes leading to dilatation of the stomach, and which may be therefore important from a diagnostic point of view, are :
(a) Stenosis of the pylorus due to contraction of a simple ulcer.
(b) Hour-glass stricture of the stomach from contraction due to simple ulcer, leading to dilatation of the cardiac pouch.
(c) Perigastritis, leading to stricture or to kink of the pylorus.
(d) Hypertrophy of the pylorus with fibroid thickening, occasionally seen in adults, but more frequently found in infants, when it is known as " congenital hypertrophic stenosis."
(e) Pyloric spasm, a sequel of gastric ulcer, which may continue long after the ulcer has healed. Spasm of the pylorus is also a symptom of severe hyperchlorhydria, when it is known as Reichmann's disease.
(/) Polypus at the pyloric end of the stomach.
(g) Tumour outside the pylorus pressing on and obstructing it.
(h) Pressure on the duodenum by an abnormal enlargement of the pancreas, as when the inflamed head of the pancreas embraces the duodenum, or when growth of the pancreas invades it.
(i) Pressure by the mesenteric vessels as they cross the duodenum.
(j) Cholelithiasis producing ulceration and inflammatory thickening of the pylorus and first part of the duodenum.
(A) Kink of the pylorus due to the dragging by a movable right kidney.
(I) Kink of the pylorus due to gastroptosis.
The diagnosis of cancer from other conditions leading to dilatation is fully considered in the chapter dealing with diagnosis generally.
The first effect of stenosis when not sufficient to produce complete obstruction is to cause increased peristalsis in order to overcome the obstruction. When the health is otherwise good this compensatory hypertrophy enables a moderate degree of obstruction to be overcome. As soon, however, as compensation fails, retention of food and of the gastric secretion takes place. Fermentation of the retained contents then follows, leading to sub-acute gastritis or catarrh, the first result of which is to weaken the muscular wall of the stomach. For a time relief may be obtained by vomiting, which takes place at irregular intervals. Early in the history of dilatation vomiting may only occur every second or third day, but as the obstruction increases it occurs daily, and ultimately may take place after every meal. As the result of these pathological changes wasting occurs, and as less and less fluid becomes absorbed from the diseased stomach there is great thirst, increasing constipation, and diminished excretion of urine; and when the obstruction finally becomes complete death occurs from starvation.
According to the extent of the ulceration and the amount of cicatricial contraction the symptoms may be hastened or delayed, so that in some cases months or even years may pass before the final stage is reached if the disease be simple; but it must be borne in mind that cancer may be grafted on chronic ulcer. The length of time that symptoms have been present does not, therefore, exclude the possibility of cancer.
The various forms of pyloric obstruction mentioned under the different causes do not all pursue so slow a course. For instance, the inflammation dependent on pyloric or duodenal ulcer may be so acute as to cause great swelling that may rather acutely block the outlet of the stomach, and the supervention of spasm may lead to an acute exacerbation of symptoms previously chronic.
In considering the clinical history, it is necessary therefore to take into consideration the cause of the stenosis, and secondly the symptom due to dilatation per se.
After an ordinary meal the stomach should be found empty in about six or seven hours. If the motor functions of the stomach are impaired the remains of food will be found later than this : for instance, when the dilatation is well marked and the stomach is washed out early in the morning*, the remains of the supper of the previous evening may be found in it. If the obstruction is not complete, and there is a certain amount of muscular power in the gastric walls, the patient may only complain of a sense of weight and discomfort in the epigastrium, and of flatulency. In well-marked cases visible peristalsis from left to right is seen-a symptom which is almost pathognomonic of mechanical obstruction, and in such cases vomiting will almost certainly be a prominent symptom. The vomit in obstructive dilatation is quite characteristic, in that it is large in amount and characterised by the presence of well-marked fermentation. It may contain particles of food that have been taken days before. If allowed to stand the vomit will usually separate into three layers, a sediment consisting of solid particles of food, a central layer of dirty greyish fluid, and a scum of frothy fermenting material, in which will be found yeast cells and sarcinae. In quite a number of cases of gastrectasis from simple pyloric stenosis, tetany in a greater or less degree is a marked symptom, which may even lead to a fatal issue. A physical examination before the stomach has emptied itself will usually yield a well-marked succussion splash, and on distending the stomach with carbonic acid gas or air, gastric resonance may be found in severe gastrectasis to reach to the pelvis; but even when the dilatation is only moderate in extent the stomach will usually reach well below the umbilicus.
In rare cases of simple stenosis, a tumour may be felt, but, as a rule, in stenosis from ulcer, the pylorus is fixed by adhesions under cover of the liver, and unless the thickening is considerable it is difficult to discover any tumour on palpation. A palpable tumour, especially if it be freely movable, is more likely to be due to cancer than ulcer, though this rule is not absolute.
Hyperchlorhydria is usually present in simple cicatrical stenosis, though if the dilatation has existed for a long time the peptic glands may be seriously damaged and free HCl may be absent, as it usually is in malignant disease.
Where there is a chronic ulcer, blood may be found on microscopic examination, but coffee-ground vomiting is less characteristic of this form of stenosis than when the dilatation is dependent on cancer.
Pain is usually present at some stage of the disease. It may vary with the cause : for instance, if from ulcer at the pylorus it usually occurs two to three hours after a meal, and may be relieved by food in the earlier stages; if from cancer there may be little pain for a time • but as the disease progresses, painful peristalsis may occur at irregular intervals and may be increased by food.
When the dilatation becomes extreme there may be merely a sense of weight and fulness due to the accumulation of food, secretions, and flatus, which may be relieved by vomiting or by lavage of the stomach.
The final stages are characterised by subnormal temperature, coldness and lividity of the extremities, and extreme loss of strength, ending in death from exhaustion.
In the early stages of obstructive dilatation when the symptoms are slight, relief for a time will, doubtless, have been given by lavage of the stomach and the observance of a strict diet; but as soon as the symptoms are pronounced it is a mere waste of time to persevere with the use of drugs, massage, electricity, or even lavage, except in those rare cases where the stenosis is due either to syphilitic ulcer or gumma, which should speedily respond to specific treatment.
Surgical treatment is alone of avail in order to remove the cause of the stenosis or to create a new channel by which the stomach contents may pass onwards into the intestines.
It may sometimes be possible to remove the cause of the stenosis by division of peritoneal bands or adhesions, or the removal of a tumour obstructing the pylorus, but in the majority of cases of cancer it will be necessary either to do a partial gastrectomy or to perform a gastroenterostomy.
Pylorectomy or partial gastrectomy is a much more severe procedure than gastro-enterostonry, but there is a certain class of cases in which it is difficult to say whether the disease is simple or malignant. If malignant, partial gastrectomy including the pyloric orifice should certainly be performed if the disease is not too extensively involving the lymph-glands or associated with secondary growths.
If the obstruction of the pylorus is associated with a tumour due to inflammatory disease, in all probability it will be so adherent to the under surface of the liver or to the pancreas that pylo-rectomy will be extremely difficult and hazardous. In such cases it will probably be deemed necessary to rest content with gastroenterostomy in the hope that the rest induced by the operation will cause a subsidence of the tumour. I have found this to apply in many such cases in which at the time there was a question of malignant disease.
If, however, under these circumstances the tumour should be free from adhesions and the disease limited to the neighbourhood of the pylorus, it may be quite justifiable to perform pylorectomy in case of doubt.