Oesophageal portosystemic anastomosis (left gastric to azygos)
Termination
In portal hypertension, flow reverses (becomes hepatofugal) up the left gastric vein into the submucosal veins of the lower oesophagus, which drain through oesophageal tributaries of the azygos and hemiazygos veins to the SVC. It is the most dangerous of the four anastomoses because the distended veins lie in the submucosa of the lower 5 cm of the oesophagus, where they are exposed to trauma and acid.
Traced from the start
- Inferior mesenteric veinShort gastric and left gastro-omental veins
- Jejunal, ileal, ileocolic, right colic and middle colic veinsRight gastro-omental and pancreaticoduodenal veins
- Oesophageal veins (lower third)
- Splenic veinSuperior mesenteric veinLeft gastric (coronary) vein
- Hepatic portal vein
- Oesophageal portosystemic anastomosis (left gastric to azygos)
Detail
- Portal limb
- Left gastric vein and its oesophageal tributaries
- Systemic limb
- Oesophageal veins to azygos and hemiazygos, then SVC
- Produces
- Oesophageal varices (and cardia or gastric varices)
When it goes wrong
Portal hypertension with a hepatic venous pressure gradient of 12 mmHg or more
Oesophageal varices in the lower third; rupture causes massive painless haematemesis and melaena with shock, and roughly a third of cirrhotics with varices bleed
Acute variceal haemorrhage
Resuscitate, give terlipressin (or octreotide) and intravenous antibiotics, then urgent endoscopic band ligation; balloon tamponade or TIPS if uncontrolled; non-selective beta-blocker (propranolol or carvedilol) or banding for prevention
Practise this structure
No question in the bank is tagged to Oesophageal portosystemic anastomosis (left gastric to azygos) yet. Questions appear here automatically once one is — the question bank is free to browse in the meantime.