Angiodysplasia of the stomach and duodenum

Twenty-five angiodysplasias in the stomach and duodenum were identified with endoscopy in 12 patients. The average age of the patients was 70 years. Two patients had aortic stenosis. Six of the patients were treated with electrocoagulation, three of whom required surgery. Angiodysplasia of the upper gastrointestinal tract is considered to be more common than previously thought and an important cause of both obscure and overt bleeding.     

Crohn''s disease of the stomach and duodenum

Clinical and radiological abnormalities in 12 patients with gastroduodenal involvement were encountered amongst 300 patients followed by one of us between 1944 and 1969. Symptoms of dyspepsia were relatively mild and obstructive symptoms when present were readily relieved by bypass surgery. The patients have been followed for a mean of 9.7 years (range 1-20); two have died of other causes but the remaining 10 are well.     

Toxicity of NSAIDs in the stomach and duodenum.

NSAIDs are widely used for analgesic, anti-inflammatory and anti-thrombotic indications. Such use carries the risk of gastrointestinal complications (1% over 6 months) which NSAIDs may promote from both ulcerous and nonulcerous lesions. Symptoms are poor predictors of serious lesions and complications, which may occur without previous symptoms. NSAIDs also delay healing of peptic ulcers, even to the extent of intractability, and may cause recurrence after gastric surgery. Prophylactic therapy is indicated in high-risk patients (age > 60 years, previous ulcer history, high dose, concomitant use of corticosteroids or anticoagulants). Misoprostol, omeprazole and high-dose famotidine have been shown to reduce the occurrence of both gastric and duodenal ulcers in NSAID users. At present, the role of Helicobacter pylori in NSAID-induced gastroduodenal lesions is controversial and there is no agreement in considering the organism as a risk factor and indicating its eradication in NSAID users.     

Magnet-tipped tubes for studies of the stomach and duodenum

The placement of gastrointestinal tubes into the gastric antrum and duodenum is facilitated by a simple technic which depends upon magnet-tipped tubes. The method is efficient at the bedside and in the examining room, without the need for roentgen confirmation; it is based upon the detection of a magnetic field which appears upon the skin within 6–10 cm of the magnet. Although sensitive electronic equipment may be used for measurement of these magnetic field projections, a small plotting compass serves well for clinical purposes and is more rapid. In 34 of 36 consecutive studies, the magnet-tipped tube was placed correctly into the gastric antrum, and the collection holes were positioned properly for quantitative gastric analysis. In 24 of 28 consecutive duodenal intubation studies, the magnet-tipped tube was placed correctly into a proper position for the collection of duodenal secretions. This simple method can be used to assure proper localization of various tubes in the stomach and duodenum.The assistance of Mr. Adolphus Jones in the performance of many of these studies is gratefully acknowledged.     

Adherent and soluble mucus in the stomach and duodenum

Gastroduodenal mucus is present as a water insoluble gel adherent to the mucosal surface and as a viscous mobile solution in the lumen. The protective properties of the mucus against acid (with bicarbonate), pepsin (diffusion barrier) and mechanical damage depend on the quality (structure) and quantity (thickness) of the adherent mucus gel layer. Adherent mucus is a viscoelastic gel which is 95% (v/v) water. It is permeable to ions and smaller molecules (M_r c. 1000), but is impermeable to large proteins (M_r,c. 17,000) including pepsins. However, mucus is solubilized rapidly by pepsin, more slowly (>-1 h) by thiol agents, and is unchanged following exposure to bile, acid and ethanol (<40%). Glycoprotein macromolecules (M_r≥2×10⁶) are the structural components of the mucus gel and have a polymeric, structure of glycoprotein subunits (M_rc. 5×10⁵, for gastric mucus) joined by disulphide bridges between their protein cores. This glycoprotein polymerization, which is essential for gel formation and hence function, is the site of action of proteolytic enzymes and thiol agents. The glycoprotein polymeric structure is deficient in antral mucus from patients with peptic ulcer disease.In vivo, adherent mucus forms a thin but continuous cover of variable thickness (50–450 μm in man, about two-fold less in rat) over the gastroduodenal mucosa. Pepsin in gastric juice will rapidly dissolve this mucus cover and can be active up to luminal pH values of 5. Mucus erosion by pepsin or by abrasion must be balanced by its secretion. Prostaglandins and carbachol stimulate a rapid increase (within minutes) in mucus thickness of up to two-fold. Soluble luminal mucus can be increased by mucus secretagogues, mucosal damaging agents, or peptic degradation of adherent mucus. Increases in luminal mucus can occur independently of increased gel thickness.