Gastroscopy technique

Anatomy

• Upper third - aortic arch - 22cm
• Middle third - left main bronchus - 27cm. left atrium can also cause compression here when enlarged.
• Lower third - diaphragmatic opening - 38cm

Intubating oesophagus

• Should be done under direct vision
• Pushing through resistance leads to trauma, oedema and spasm. Withdraw, confirm position. If it is not possible to pass to the right of the arytenoid, pass on the left. If this still fails, ask for more chin lift, and check the patient is fully in the left lateral position with slight neck flexion.
• Intubated patients might need the ETT balloon slightly deflated to allow intubation.
• If there is a Zenker's diverticulum, carefully establish which is the true diverticulum. Can use a guidewire to probe gently.

Hiatus hernia

• Document length (diaphragmatic impression to z-line)
• Check for Cameron lesions
• Retroflex and grade

GOJ

• Defined as the level of the most proximal extent of the gastric folds, or the most distal extent of the palisading oesophageal blood vessels
• Biopsy indications
  • Hiatus hernia
  • Oesophagitis or suspected Barrett's
• Classify oesophagitis according to LA classification
• Classify Barrett's according to Prague classification (C and M)
  • If present, biopsy according to Seattle protocol (four-quadrant biopsies every 2cm for non-dysplastic or 1cm for dysplastic, starting 1cm above GOJ)
  • White light and NBI
  • Look carefully for any ulcers/nodules

Duodenal biopsies

• Indications:
  • IDA with no identified cause
  • Folate deficiency (combined with gastric biopsies)
  • Other nutritional deficiencies
  • Isolated chronic diarrhoea
  • Dermatitis herpetiformis
  • Confirmation of coeliac disease in patients with positive serology (optimal number of biopsies for diagnosis is four)
  • If parasitic disease is suspected when a parasitological stool examination has been negative (giardiasis, strongyloidiasis)

Other lesions

• All lesions are biopsied except for vascular malformations and duodenal ulcers
• Eosinophilic oesophagitis - biopsy multiple times along the oesophagus
• Possible cancers
  • Classify endoscopically with Paris system (note that Paris is basically the same as Borrman, with a few extra categories)

Commonly-missed lesions

• Portal hypertensive gastropathy
• Vascular malformations
  • Isolated
  • GAVE
• Ulcers
  • Dieulafoy lesions
  • Cameron lesions
  • Posterior cap in D1
  • D2
• Colorectal cancer