Retroperitoneal portosystemic anastomoses (veins of Retzius) and bare area of the liver

Termination

Where gut lies against the posterior abdominal wall, the colic, duodenal and pancreatic veins (portal) communicate with the lumbar, renal, gonadal and adrenal veins (systemic, to the IVC), the veins of Retzius, and the splenic vein communicates with the left renal vein. Over the bare area of the liver, small portal branches communicate with the inferior phrenic veins. These deep collaterals are usually silent but can carry large flows.

Traced from the start

  1. Inferior mesenteric veinShort gastric and left gastro-omental veins
  2. Jejunal, ileal, ileocolic, right colic and middle colic veinsRight gastro-omental and pancreaticoduodenal veins
  3. Oesophageal veins (lower third)
  4. Splenic veinSuperior mesenteric veinLeft gastric (coronary) vein
  5. Hepatic portal vein
  6. Retroperitoneal portosystemic anastomoses (veins of Retzius) and bare area of the liver

Detail

Portal limb
Colic, duodenal and pancreatic veins; splenic vein
Systemic limb
Lumbar, renal, gonadal and adrenal veins to the IVC; inferior phrenic veins at the bare area
Produces
Retroperitoneal varices and spontaneous splenorenal shunts

When it goes wrong

Spontaneous splenorenal or gastrorenal shunt in cirrhosis

Large-volume shunting causes hyperammonaemia and hepatic encephalopathy even when varices are few; the shunt is visible on CT and can be embolised

Retroperitoneal varices encountered at colectomy, splenectomy or liver transplantation in portal hypertension

Unexpected heavy venous bleeding from the posterior abdominal wall; rarely, spontaneous retroperitoneal or intraperitoneal haemorrhage

Practise this structure

2 questions in the bank tagged Peritoneal Versus Retroperitoneal.