Circulatory disorders of the liver
How blocks at the liver’s inflow, sinusoids and outflow change its circulation: portal vein thrombosis, the rare liver infarct, sinusoidal obstruction syndrome, Budd–Chiari syndrome and cardiac cirrhosis, and the shock liver of low blood flow.
By the end, you can
- Explain how the liver’s dual inflow and the hepatic arterial buffer response protect it, and why liver infarcts are rare.
- Classify hepatic circulatory disorders by the site of the block and predict what each does to portal pressure, congestion and liver function.
- Explain portal vein thrombosis, sinusoidal obstruction syndrome and Budd–Chiari syndrome, with their main causes.
- Explain why low blood flow or oxygen kills the zone 3 hepatocytes first, and how ischaemic hepatitis differs from viral hepatitis.
- Recognise the classic appearances, pressure measurements and tests of these disorders, and explain how anticoagulants, thrombolysis, shunts and restoring perfusion act on the mechanism.
What it is
Circulatory disorders of the liver are diseases in which blood cannot enter, cross or leave the liver normally. They are grouped by the site of the block: inflow (the portal vein or the hepatic artery), the sinusoids, and outflow (the hepatic veins, the inferior vena cava or the right heart). A block raises the pressure upstream of it and may congest the liver or starve it of oxygen; a general fall in blood flow or oxygen causes ischaemic hepatitis (shock liver).
4 types to tell apart
- Inflow (pre-sinusoidal)
- Portal vein thrombosis raises portal pressure without congesting the liver; hepatic artery occlusion rarely causes an infarct because portal blood still arrives.
- Sinusoidal
- Sinusoidal obstruction syndrome and peliosis hepatis injure the sinusoidal lining; cirrhosis also raises resistance mainly here.
- Outflow (post-sinusoidal)
- Budd–Chiari syndrome blocks the hepatic veins or vena cava; right heart failure and constrictive pericarditis congest the liver from the heart.
- Global hypoperfusion
- Low cardiac output, low blood pressure or low blood oxygen injures the whole liver at once, worst round the central veins: ischaemic hepatitis.
US spelling: ischaemic → ischemic, ischaemia → ischemia.
Normal function
Two ways in, one way out
The receives about a quarter of the cardiac output through two inflows. The , formed by the and , brings two thirds to three quarters of the blood, at low pressure and already partly deoxygenated by the gut; the brings the rest, fully oxygenated. Each supplies roughly half of the liver’s oxygen.
The two inflows are linked. When portal flow falls, the hepatic artery dilates and carries more blood: the hepatic arterial buffer response (in the usual explanation, adenosine normally washed away by portal blood builds up round the arterioles and dilates them). The dual supply and this buffer protect the liver from ischaemia. The reverse does not happen: portal flow is set by the gut, not by the liver.
Both streams mix in the sinusoids and flow past the hepatocytes from the portal tracts (zone 1, best oxygenated) to the central veins (zone 3, least oxygenated). Central veins join to form the , which enter the just below the right atrium. The pressure drop across the liver is normally only about 5 mmHg or less, so a block at any level raises the pressure upstream of it.
- Portal and arterial blood mix (from Inflow: portal vein and hepatic artery to Sinusoids, zone 1 to zone 3)
- Central veins collect it (from Sinusoids, zone 1 to zone 3 to Outflow: hepatic veins and vena cava)
- Into the right atrium (from Outflow: hepatic veins and vena cava to Right heart)
Schematic. Pressure rises upstream of any block; only blocks at or beyond the sinusoids congest the liver.
Underlying change · Step 1 of 5
Inflow: a clot in the portal vein
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 2 of 5
Inflow: why the liver rarely infarcts
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Underlying change · Step 3 of 5
Within the liver: injured sinusoids
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 4 of 5
Outflow: Budd–Chiari syndrome and the congested liver
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
Low flow: ischaemic hepatitis (shock liver)
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Exam detail
Exam detail
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Treatment
How treatment works
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .