Gastric disorders

ACUTE GASTRIC DILATATION

This is an uncommon but serious condition. The use of nasogastric suction has greatly reduced its frequency in the postoperative period. Gastric dilatation may also occur after trauma, the use of body casts, pneumonia, diabetic acidosis, or large doses of anticholinergic drugs. It is a rare complication of many diseases and also may occur for no apparent reason. The patient complains of anorexia and epigastric fullness and often vomits small amounts of fluid. Increasing abdominal distention with tympany, especially in the left hypochondrium, and a succussion splash are demonstrable. Untreated, large volumes of fluid are sequestered in a gastric "third space" with resultant sodium and potassium depletion. The patient becomes restless and listless; hypovolemia, tachycardia, reduced urine output, and, finally, shock develop. Aspiration pneumonia may occur. X-ray of the abdomen shows massive gastric distention with an air-fluid level. Continuous nasogastric suction and restoration of fluid and electrolyte balance result in rapid improvement.

ADULT HYPERTROPHIC PYLORIC STENOSIS

In this uncommon condition, the pyloric muscle is enlarged because of hypertrophy and possibly hyperplasia of the fibers of the circular layer. Many cases are associated with a peptic ulcer near the pylorus. In others, the pyloric muscle hypertrophy has been attributed to associated antral gastritis or neoplasm. A minority of cases without other gastric disease may be due to unrecognized infantile hypertrophic pyloric stenosis. Most often symptoms of pyloric obstruction such as nausea, vomiting, and epigastric fullness develop in mid-adult life, although occasionally mild symptoms are lifelong. An epigastric mass is not palpable in adults as it is in infants. Barium x-ray studies show a long, narrowed pyloric canal, often with triangular outpouchings within the canal. Gastroscopy shows a narrowed pylorus that is fixed in the open position. Although the diagnosis often appears highly likely from the above studies, an infiltrating cancer may be difficult to exclude without operation. A limited gastric resection is said to give better symptomatic relief than a pyloromyotomy, and in addition it provides an exact histologic diagnosis. The frequently associated juxtapylorjc ulcers merit vagotomy.

BEZOARS AND FOREIGN BODIES

Conglomerates of food and mucus or phytobezoars composed of vegetable matter sometimes form in the gastric remnant after partial gastrectomy, especially if a vagotomy was also performed. They occur less often after vagotomy and pyloroplasty. Autonomic neuropathy associated with diabetes mellitus is another predisposing condition. Rarely yeast bezoars have been found. Patients complain of anorexia, epigastric fullness, nausea, or vomiting. The diagnosis is often apparent from the barium x-ray examination, but endoscopy may be needed to distinguish the food mass from a neoplasm. The food conglomerate or bezoar can often be removed by vigorous and repeated gastric lavage. Fragmenting the lesion at gastroscopy may facilitate removal by lavage. Some phytobezoars can be partially digested with cellulase and then broken up successfully by lavage. Occasionally surgical removal is necessary. If the mass passes into the small bowel, it can cause obstruction requiring surgery. Treatment with metoclopramide and a low-fiber diet may be tried to prevent recurrence.

Bezoars in the intact stomach are rare. Phytobezoars are most common, a well-known type being the persimmon ball. Trichobezoars are composed of hair. Concretions of inorganic substances such as shellac, asphalt, or calcium carbonate are occasionally seen. Bezoars of the intact stomach often require surgical removal, although nonoperative methods may be successful for phytobezoars. Persimmon balls have responded to treatment with papain and sodium bicarbonate.

Small foreign bodies such as coins, marbles, or even closed safety pins usually pass through the stomach and bowel without difficulty. Elongated, sharp objects such as needles, toothpicks, or open safety pins may hold up at some point and cause obstruction, ulceration, bleeding, abscess, or peritonitis. Occasionally, large objects such as forks or knives are swallowed by emotionally disturbed persons. Patients who have swallowed dangerous objects should be promptly referred to an experienced endoscopist who may elect endoscopic removal, observation, or surgical treatment.

GASTRIC DIVERTICULA

These uncommon lesions usually occur just below the cardia on the posterior wall near the lesser curvature. Almost all are asymptomatic and require no treatment. Pain, bleeding, and perforation are rare complications. Surgery should not be undertaken except for severe intractable symptoms that cannot be attributed to another cause. The x-ray appearance is usually diagnostic, but occasionally gastroscopy is needed to distinguish the lesion from a peptic ulcer.

GASTRIC VOLVULUS OR TORSION

Rarely the stomach can twist about its longitudinal axis, thus turning itself upside down and obstructing the lower esophagus. The volvulus may be acute but is more often chronic. It tends to be associated with a paraesophageal hernia or eventration of the diaphragm. The stomach can also twist about the vertical axis of the gastrohepatic omentum to produce a torsion rather than a true volvulus. Acute volvulus is associated with severe upper abdominal pain and retching which produces saliva rather than gastric or duodenal contents. Passage of a nasogastric tube beyond the cardia is usually impossible. Plain x-ray films of the abdomen show distention of the stomach; the finding of two separate fluid levels is diagnostic. Acute volvulus may be of short duration and may subside spontaneously or may be associated with strangulation and require emergency surgical treatment. Those with chronic volvulus may be asymptomatic or have intermittent pain, often associated with eating. Severe symptoms may require surgical correction of the volvulus, including repair of an associated paraesophageal hernia, if present.

RARE GASTRIC DISEASES

Pseudolymphoma This is a localized benign lymphoid hyperplasia of the stomach. Its etiology is unknown, but in some instances it is a reaction to a benign gastric ulcer. Grossly the lesion is usually single and ulcerated. Some lesions are nodular; others may present as enlarged tolds. I he x-ray and endoscopic findings may suggest either malignancy or peptic ulcer. There is marked lymphocytic infiltration of the gastric wall which may be transmural. Partial gastrectomy is usually required for diagnosis and treatment. The lesion may be distinguished from true lymphoma by the polyclonal nature of the infiltrate shown by immunohistochemical staining.

Eosinophilic gastroenteritis The antrum may be involved in this condition, which is associated with marked peripheral eosinophilia. The diagnosis can be made by mucosal biopsy, and chronic treatment with small doses of corticosteroids is usually effective.

Inflammatory fibroid polyp This is usually a circumscribed lesion of the antrum and is not associated with peripheral eosinophilia. In the past it has been called eosinophilic granuloma but this is a misnomer. It does not respond to corticosteroid treatment and may require excision because of pyloric obstruction or other symptoms.

Gastric granulomas Epithelioid granulomas of the stomach are most commonly caused by Crohn's disease and only rarely are a manifestation of sarcoid or tuberculosis. Some granulomas adjacent to peptic ulcers are foreign-body reactions. Idiopathic isolated granulomas often prove to be due to Crohn's disease or may be a manifestation of immunoglobulin deficiency or of chronic granulomatous disease.

Other specific gastritides Tuberculosis and tertiary syphilis rarely affect the stomach. The diagnosis can sometimes be made from the clinical picture and endoscopic biopsy, but more often operation is needed to exclude malignancy. Appropriate antibiotic therapy is effective. Gastric infections, particularly candidiasis but also cytomegalovirus, herpes simplex, and histoplasmosis, are occasionally seen in immunosuppressed patients. Gastric anisakiasis is a nematode infection of the stomach acquired by eating raw fish. Previously, it was largely confined to Japan, where sashimi (raw fish) is a delicacy. It is now seen occasionally in the United States, where sashimi has become popular.