- Ascites is free fluid within the abdominal cavity
- Over 70% cases due to liver disease.
Aetiology
The main causes of ascites include the following conditions
- Hepatic - cirrhosis, veno-occlusive disease
- Cardiac - right ventricular failure, constrictive pericarditis
- Renal - nephrotic syndrome, renal failure
- Malignancy - ovarian, gastric, colorectal carcinoma
- Infection - tuberculosis
- Pancreatitis
- Lymphatic - congenital anomaly, trauma
- Malnutrition
- Myxoedema
Investigation
A diagnostic peritoneal tap allows peritoneal fluid to be sent for:
- Protein estimation
- A transudate has a total protein < 30 g/l - cirrhosis, heart failure
- An exudate has a total protein > 30 g/l - carcinomatosis, infection
- Cytology
- Bacteriology
- Biochemistry - amylase, CEA
Pathophysiology
- The normal peritoneal cavity contains ~100 ml of fluid
- It is a transudate and has a 50% turnover per hour
- It is produced by visceral capillaries
- It is drained via diaphragmatic lymphatics
- In cirrhotic ascites pathophysiology is complex
- Portal hypertension results in splanchnic vasodilatation
- Results in sodium retention due to:
- Altered systemic haemodynamics
- Altered neurohumeral control
- Altered renal function
- Impaired free-water excretion results in dilutional hyponatraemia
- Renal vasoconstriction results in hepatorenal syndrome
Complications
- Spontaneous bacterial peritonitis
- Hepatorenal syndrome
- Hepatic hydrothorax
Treatment of ascites in cirrhosis
- Effective treatment is difficult
- Medical measures include sodium restriction and diuretics
- Spironolactone is usually drug of choice
- In those with ascites refractory to medical therapy options include:
- Repeated large-volume paracentesis
- Peritoneovenous shunting
- Portocaval shunting
- Transjugular intrahepatic portosystemic shunting
- Liver transplantation
Transjugular intrahepatic portosystemic shunting
- Involves the creation of an intrahepatic portosystemic shunt
- Hepatic vein is cannulated via the internal jugular vein
- Intrahepatic portal vein punctured percutaneously
- Guide wire passed from portal to hepatic vein
- Stent is then passed along guide wire
- Complications include encephalopathy and liver failure
- Has improved survival compared with other technique
Bibliography
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Howard E R, Khawaja H T. Management
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Jeffery J, Murphy M J. Ascitic fluid analysis: the role of biochemistry and
haematology. Hosp Med 2001; 62: 282-286.
Rossle M, Ochs A, Gulberg
V. A comparison of paracentesis and transjugular intrahepatic portosystemic shunting in patients
with ascites. N Eng J Med 2000; 342:
1701-1707.
Walsh K, Alexander G. Alcoholic
liver disease. Postgrad Med J 2000;
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