Portal Triad Contents
The portal triad — bile duct, portal vein, and hepatic artery — is the fundamental anatomical unit of the liver lobule. At the porta hepatis it can be surgically controlled with the Pringle manoeuvre.
✦ The Mnemonic
"Bills Vary Artistically — Bile duct, Portal Vein, Hepatic Artery"
Right to left at porta hepatis: Bile duct · Portal vein · Hepatic artery
Clinical Breakdown
Within the hepatic lobule, the portal triad sits at the corner; the central vein at the centre. Blood flows portal triad → sinusoids → central vein. Zone 1 (periportal) most susceptible to ischaemic injury; Zone 3 (centrilobular) most susceptible to toxic/congestive injury.
At the porta hepatis, right to left: Bile duct · Portal vein · Hepatic artery. These run in the hepatoduodenal ligament (free edge of lesser omentum). Compressing it between finger and thumb = Pringle manoeuvre — stops all hepatic inflow.
Couinaud's segmental anatomy divides the liver into 8 functional segments (I–VIII) based on portal pedicles and hepatic vein drainage — enabling anatomical resection without compromising adjacent segments.
⭐ Clinical Pearl
Portal hypertension varices: oesophageal (left gastric ↔ azygos), haemorrhoidal (superior ↔ middle/inferior rectal), caput medusae (para-umbilical ↔ epigastric), retroperitoneal (veins of Retzius). Oesophageal variceal bleeding carries 30–50% in-hospital mortality.