Gastric Outlet Obstruction

A gastric bezoar is an intragastric mass of indigestible material that fails to pass through the pylorus.

Important types are:

• Phytobezoar: vegetable and fruit fibre, the commonest type
• Trichobezoar: hair, usually associated with trichotillomania and trichophagia
• Pharmacobezoar: concreted medication
• Lactobezoar: concentrated milk material, mainly in infants

Predisposing factors are impaired gastric emptying and altered gastric anatomy. Previous vagotomy, pyloroplasty, partial gastrectomy, diabetes with gastroparesis and poor dentition are particularly relevant.

Persimmon phytobezoars are unusually hard because tannins polymerise within the acidic stomach and are more resistant to chemical dissolution.

Small bezoars may be incidental.

Larger bezoars cause early satiety, epigastric discomfort, nausea, vomiting, anorexia and weight loss.

Complications include:

• Gastric outlet obstruction
• Gastric ulceration and bleeding
• Small bowel obstruction after distal migration
• Perforation, rarely

A trichobezoar extending from the stomach into the small bowel is termed Rapunzel syndrome and can produce obstruction, ulceration or perforation.

Upper gastrointestinal endoscopy: confirms the bezoar, defines its composition and size, assesses associated ulceration and allows treatment.

CT abdomen: use when small bowel obstruction, perforation or distal migration is suspected.

The underlying cause should also be identified. A bezoar in an adult without obvious anatomical explanation should prompt assessment for gastroparesis, previous surgery, medication effects or impaired mastication.

Treatment depends on composition and complications.

Phytobezoar

Chemical dissolution can be attempted in a stable patient without perforation, major bleeding or distal obstruction.

Coca Cola has been used successfully to soften and dissolve phytobezoars. A commonly described regimen is approximately 3 litres administered orally or through a nasogastric tube over about 12 hours, although there is no universally standardised dose. It is often more useful as a softening treatment before endoscopic fragmentation than as definitive treatment alone.

Avoid this strategy in patients at high aspiration risk, significant fluid restriction or poorly controlled diabetes without appropriate modification.

Persimmon bezoars commonly require endoscopic fragmentation because they are relatively resistant to dissolution.

Endoscopic treatment

Endoscopic fragmentation and removal is appropriate when:

• Dissolution fails
• Symptoms are significant
• Gastric outlet obstruction is developing
• The bezoar is large or hard
• Associated ulceration or bleeding requires treatment

Snares, retrieval nets, baskets and forceps can be used to fragment and extract the mass.

Fragments should be reduced sufficiently to avoid creating a downstream small bowel obstruction.

Trichobezoar

Trichobezoars respond poorly to chemical dissolution because compacted hair is resistant to enzymatic degradation. Large trichobezoars usually require surgical removal, particularly when there is Rapunzel syndrome or extension beyond the stomach.

At surgery, inspect the small bowel for satellite bezoars before closure.

Treat associated psychiatric disease to reduce recurrence.

Surgery

Operate for:

• Perforation
• Small bowel obstruction not amenable to endoscopic treatment
• Major uncontrolled bleeding
• Large trichobezoar
• Failed endoscopic therapy
• Bezoar too large or dense for safe fragmentation

After removal, treat the underlying gastric emptying disorder and address dietary factors because recurrence is otherwise possible.