Circulatory disorders (END) Flashcards
What is the effect of hepatic artery inflow interruption?
Rarely leads to ischemic necrosis due to dual blood supply from the hepatic artery and portal vein.
Exception: Hepatic artery thrombosis in a transplanted liver can cause organ loss.
What happens if there is thrombosis or compression of an intrahepatic branch of the hepatic artery?
Leads to a localized parenchymal infarct.
What are the causes of extra-hepatic portal vein obstruction?
Peritoneal Sepsis:
Conditions like acute diverticulitis or appendicitis causing pylephlebitis in the splanchnic circulation.
Pancreatitis:
Leading to splenic vein thrombosis & subsequent portal vein thrombosis.
Thrombogenic diseases & post-surgical thrombosis.
Vascular invasion by primary or secondary cancer in the liver.
Cirrhosis:
Reduces portal vein blood flow, predisposing to thrombosis.
What are the clinical features of portal vein (or major branch) occlusion?
Abdominal pain.
Ascites.
Esophageal varices.
Acute visceral blood flow impairment, leading to congestion and bowel infarction.
What are the effects of acute intra-hepatic thrombosis of a portal vein branch?
Causes an infarct of Zahn, characterized by:
Sharply demarcated area of red-blue discoloration.
No necrosis but hepatocellular atrophy & sinusoidal congestion.
What is hepato-portal sclerosis?
A chronic, idiopathic (possibly autoimmune) condition involving progressive portal tract sclerosis, impairing portal vein inflow.
Causes of Passive congestion & centrilobular necrosis
Systemic circulatory disorders:
Right-sided cardiac Decompensation → Passive Congestion of the Liver
Long-standing cases → Centri-Lobular necrosis and perivenular fibrosis in the necrotic areas
Lab findings of Passive congestion & centrilobular necrosis
Mild elevation of serum transaminase levels – Hyper-bilirubinaemia & elevated alkaline phosphatase (some cases)
What are the macroscopic features of the liver in right-sided cardiac failure?
Slightly enlarged liver.
Tense and cyanotic appearance.
What are the microscopic findings in right-sided cardiac failure?
Congestion of centri-lobular sinusoids.
Atrophic centri-lobular hepatocytes with markedly attenuated liver cell cords.
What is “Cardiac Sclerosis” or “Cardiac Cirrhosis”?
Chronic severe congestive heart failure causes centri-lobular fibrosis.
Rarely forms bridging fibrous septa and cirrhosis.
What liver changes occur in left-sided cardiac failure?
Hepatic hypo-perfusion and hypoxia lead to:
Ischemic necrosis of centri-lobular hepatocytes and bile ducts.
What results from combined left-sided hypo-perfusion and right-sided retrograde congestion?
Centri-lobular hemorrhagic necrosis.
What is the macroscopic appearance of the liver in centri-lobular hemorrhagic necrosis?
Variegated, mottled appearance.
“Nutmeg liver” pattern: Centri-lobular areas of hemorrhage and necrosis alternate with pale mid-zonal areas.
What is the synonym for Hepatic Vein Thrombosis?
Budd-Chiari Syndrome.
What are common causes or associations with Budd-Chiari Syndrome?
Polycythaemia Vera.
Pregnancy.
Use of oral contraceptives.
Paroxysmal Nocturnal Haemoglobinuria.
Hepatocellular Carcinoma.
Idiopathic in 10% of cases.
What are the clinical features of Budd-Chiari Syndrome?
Hepatomegaly.
Ascites.
Abdominal pain.
What are the macroscopic features of the liver in Budd-Chiari Syndrome?
Swollen and red-purple liver.
Tense organ capsule.
What are the microscopic findings in Budd-Chiari Syndrome?
Severe centri-lobular congestion and necrosis.
Centri-lobular fibrosis in slow-developing thrombosis.
Completely or incompletely occlusive fresh thrombi in the major vein lumen.
Organized, adherent thrombi in chronic cases.
How is Budd-Chiari Syndrome treated?
Surgical creation of a porto-systemic venous shunt.
Angiography for direct dilation of inferior vena cava obstruction.
What is the prognosis for Budd-Chiari Syndrome?
Untreated acute cases: High mortality.
Chronic cases: Far less severe, with >2/3 survival at 5 years.
What was the former name for Sinusoidal Obstruction Syndrome?
Veno-Occlusive Disease.
What are the common causes of Sinusoidal Obstruction Syndrome?
Chemotherapeutic agents (e.g., Cyclophosphamide, Actinomycin D, Mithramycin).
Total body radiation (used in pre- or post-transplantation regimens).
What is the pathogenesis of Sinusoidal Obstruction Syndrome?
Toxic injury to sinusoidal endothelium leads to:
Sloughing of damaged endothelial cells → Thrombus formation → Obstruction of sinusoidal flow.
Erythrocyte leakage into the space of Disse.
Proliferation of stellate cells and fibrosis of terminal hepatic vein branches.
