Liver and Biliary Diseases

Complication of liver cirrhosis

Hepatic encephalopathy

Hepatic encephalopathy defined as an alteration in mental status and cognitive function occurring in the presence of liver failure Result due to the portal blood bypasses the liver via the collaterals and the 'toxic' metabolites pass directly to the brain. Many 'toxic' substances including are ammonia, free fatty acids, mercaptans and accumulation of false neurotransmitters (octopamine).

Clinical features

The features are variable from day to day and include changes of intellect, personality, emotion, and consciousness also confusion, disorientation, drowsiness and coma may be developed.
Signs include:
fetor hepaticus (a sweet smell to the breath)
a coarse flapping tremor seen when the hands are outstretched and the wrists hyperextended (asterixis)
constructional apraxia, with the patient being unable to write or draw, for example, a five-pointed star
decreased mental function, which can be assessed by using A trail-making test (the ability to join numbers and letters with a pen within a certain time) is prolonged and is a useful bedside test to assess encephalopathy.

diagnosis

Diagnosis is clinical. Routine liver biochemistry merely confirms the presence of liver disease,

Management

Management consists of evacuation of the bowels and sterilizing the bowel. Restriction of protein intake is reserved for resistant cases.

Renal failure (hepatorenal syndrome)

defined as renal failure associated with severe liver disease without an intrinsic abnormality of the kidneys .the development of hepatorenal syndrome is associated with a poor prognosis with mortality more than 95% of patients dying within a few weeks of onset of renal failure.

Diagnosis

Diagnosis is established in patients with cirrhosis with very low urine sodium (<10 meq/l) and oliguria in absence of intravascular volume depletion.

Management
The most effective treatment is by liver transplantation if appropriate, treatment of underling infection , correct the volume status , avoidness of nephrotoxic drugs.

Hepatopulmonary syndrome

This is characterised by resistant hypoxaemia (PaO2 < 9.3 kPa or 70 mmHg), intrapulmonary vascular dilatation and chronic liver disease with portal hypertension.

Clinical features

Clinical features include digital clubbing, cyanosis, spider naevi and a characteristic reduction in arterial oxygen saturation on standing. The hypoxia is due to intrapulmonary shunting through direct arteriovenous communications
.
treatment
The hepatopulmonary syndrome can be treated by liver transplantation but, if severe (PaO2 < 6.7 kPa or 50 mmHg), is associated with an increased operative risk.

Vascular liver diseases

1)-Hepatic arterial disease
Hepatic arterial disease is rare and difficult to diagnose, but can cause serious liver damage. Acute heart failure sometimes causes a syndrome similar to acute hepatitis. This is usually mediated by a reduction in hepatic perfusion, and is termed 'shock liver'. Hepatic artery occlusion may result from inadvertent injury during biliary surgery or may be caused by emboli, neoplasms, polyarteritis nodosa, blunt trauma or radiation. It usually causes severe upper abdominal pain with or without signs of circulatory shock.
LFTs show raised transaminases (AST or ALT usually > 1000 U/L), as in other causes of acute liver damage. Patients usually survive if the liver and portal blood supply are otherwise normal.

2)-Portal venous diseases

Portal venous thrombos
It is is rare but can occur in any condition predisposing to thrombosis. It may also complicate intra-abdominal inflammatory or neoplastic disease, and is a recognised cause of portal hypertension.
Acute portal venous thrombosis causes abdominal pain and diarrhoea, and may lead to bowel infarction. Bowl infarction requires surgical management. used of anticoagulants . An underlying thrombophilia needs to be excluded.

Subacute thrombosis can be asymptomatic but may subsequently lead to extrahepatic portal hypertension

3)-Hepatic venous outflow obstruction

Obstruction to hepatic venous blood flow can occur in the small central hepatic veins, the large hepatic veins, the inferior vena cava or the heart. The clinical features depend on the cause and on the speed with which obstruction develops, but congestive hepatomegaly and ascites are consistent features.


Budd-Chiari syndrome
This uncommon condition is caused by thrombosis of the larger hepatic veins and sometimes the inferior vena cava.The underlying cause cannot be found in about 50% of patients but Some patients have precipitating factors are:-
haematological disorders such as primary proliferative polycythaemia, paroxysmal nocturnal haemoglobinuria and antithrombin III, protein C or protein S deficiencies
Pregnancy and oral contraceptive use,
obstruction due to tumours (particularly carcinomas of the liver, kidneys or adrenals), congenital venous webs and occasionally inferior vena caval stenosis are the other main causes.

pathology

Hepatic congestion affecting the centrilobular areas is the initial consequence; centrilobular fibrosis develops later and eventually cirrhosis supervenes in those who survive long enough.

Clinical features

Acute venous occlusion causes rapid development of upper abdominal pain, marked ascites and occasionally acute liver failure.
More gradual occlusion causes gross ascites and often upper abdominal discomfort. Hepatomegaly, frequently with tenderness over the liver, is almost always present. Peripheral oedema occurs only when there is inferior vena cava obstruction. Features of cirrhosis and portal hypertension develop in those who survive the acute event.








Investigations
1)-Liver function test
The LFTs vary considerably, depending on the presentation, and can show the features of acute hepatitis Ascitic fluid analysis typically shows a protein concentration above 30g/L (exudate) in the early stages; however, this often falls later in the disease.
2)- Doppler ultrasound examination may reveal obliteration of the hepatic veins and reversed flow or associated thrombosis in the portal vein.
3)-CT of liver may show enlargement of the caudate lobe, as it often has a separate venous drainage system that is not involved in the disease. CT and MRI may also demonstrate occlusion of the hepatic veins and inferior vena cava.
4)- Venography is only needed if CT and MRI are unable to demonstrate the hepatic venous anatomy clearly.
5)- Liver biopsy demonstrates centrilobular congestion with fibrosis, depending on the duration of the illness.

Management

Predisposing causes should be treated as far as possible;
where recent thrombosis is suspected, treatment with streptokinase followed by heparin and oral anticoagulation should be considered.
Ascites is initially treated medically but often with limited success.
Short hepatic venous strictures can be treated with angioplasty. In the case of more extensive hepatic vein occlusion, many patients can be managed successfully by insertion of a covered TIPSS followed by anticoagulation
Occasionally, a web can be resected or an inferior vena caval stenosis dilated
. Progressive liver failure is an indication for liver transplantation and life-long anticoagulation.
Prognosis
The prognosis without transplantation or shunting is poor, particularly following an acute presentation with liver failure. A 3-year survival of 50% is reported in those who survive the initial acute event.

Veno-occlusive disease

Veno-occlusive disease (VOD) is a rare condition characterised by widespread occlusion of the small central hepatic veins.
causes
Pyrrolizidine alkaloids in Senecio and
Heliotropium plants used to make teas,
cytotoxic drugs .
hepatic irradiation .
VOD may develop in 10-20% of patients following bone marrow transplantation (usually within the first 20 days.
managament
The clinical features , investigation and treatment are similar to those of the Budd-Chiari syndrome but defibrotide drugs (Defitelio , Gentum) shows promise (the drugs are a deoxyribonucleic acid derivative that binds to vascular endothelial cells, promoting fibrinolysis and suppressing coagulation).

Cardiac cirrhosis

long-standing cardiac failure and hepatic congestion cause cardiac cirrhosis.
Hepatic damage due primarily to congestion may develop in all forms of right heart failure ;the clinical features are usually dominated by the cardiac disease.,