Budd–Chiari syndrome is a condition when an occlusion or obstruction in the hepatic veins prevent normal outflow of blood from the liver.
The symptoms are non-specific and vary widely, but it may present with the classical triad of abdominal pain, ascites, and liver enlargement. Untreated Budd-Chiari syndrome can result in liver failure.
It is usually seen in younger adults, with the median age at diagnosis between 35 and 40 years, and it has a similar incidence in males and females.
Signs and symptoms
The acute syndrome presents with rapidly progressive and severe upper abdominal pain, yellow discoloration of the skin and whites of the eyes, liver enlargement, spleen enlargement, fluid accumulation within the peritoneal cavity, elevated liver enzymes, and eventually encephalopathy. The fulminant syndrome presents early with encephalopathy and ascites. Liver cell death and severe lactic acidosis may be present as well. Caudate lobe enlargement is often present. The majority of patients have a slower-onset form of Budd–Chiari syndrome. This can be painless. A system of venous collaterals may form around the occlusion which may be seen on imaging as a "spider's web". Patients may progress to cirrhosis and show signs of liver failure.
Causes
The cause of Budd–Chiari syndrome can be found in more than 80% of patients with the condition. However, in 20% of cases, there is no underlying cause discovered. These cases are known as idiopathic Budd–Chiari syndrome. Budd–Chiari syndrome may be the presenting sign of these hypercoagulable disorders.
Secondary Budd–Chiari syndrome, which is very rare compared to the primary variant, is due to compression of the hepatic vein by an outside structure (such as a tumor or polycystic kidney disease).
People who have paroxysmal nocturnal hemoglobinuria (PNH) appear to be especially at risk for Budd–Chiari syndrome, more than other forms of thrombophilia: up to 39% develop venous thromboses, and 12% may acquire Budd–Chiari.
Pathophysiology
thumb|Posterior abdominal wall, after removal of the peritoneum, showing kidneys, suprarenal capsules, and great vessels. ([[Hepatic veins labeled at center top.)]]
Any obstruction of the venous vasculature of the liver is referred to as Budd–Chiari syndrome, from the venules to the right atrium. This leads to increased portal vein and hepatic sinusoid pressures as the blood flow stagnates. The increased portal pressure causes increased filtration of vascular fluid with the formation of ascites in the abdomen and collateral venous flow through alternative veins leading to esophageal, gastric, and rectal varices. Obstruction also causes centrilobular necrosis and peripheral lobule fatty change due to ischemia. If this condition persists chronically, what is known as nutmeg liver will develop. Kidney failure may occur, perhaps due to the body sensing an "underfill" state and subsequent activation of the renin-angiotensin pathways and excess sodium retention.
Diagnosis
Budd-Chiari syndrome may present with elevated liver enzymes; alanine aminotransferase (ALT) and aspartate aminotransferase (AST) are often elevated in the acute phase and then decrease over time as chronic liver disease develops. With regards to secondary causes of hypercoagulability, 40–50% of cases of Budd–Chiari syndrome are due to myeloproliferative disorders, and these conditions each have their own specific treatments. The TIPS procedure has been shown to have good outcomes, with a 78% five-year transplant-free survival rate. Survival rates in Budd–Chiari syndrome after liver transplantation are 76%, 71%, and 68% after 1, 5, and 10 years, respectively. Important negative prognostic indicators include ascites, encephalopathy, elevated Child–Pugh scores, elevated prothrombin time, and altered serum levels of various substances (sodium, creatinine, albumin, and bilirubin). Survival is also highly dependent on the underlying cause of the Budd–Chiari syndrome. For example, a patient with an underlying myeloproliferative disorder may progress to acute leukemia, independently of Budd–Chiari syndrome.
Eponym
It is named after George Budd, a British physician, and Hans Chiari, an Austrian pathologist.