Cirrhosis: cirrhosis of the liver. It is an untreatable, lethal disease. Any study of the prognosis of cirrhosis in Britain is likely to find that, from the time of diagnosis, half are dead within one year, and very few will survive five years. Many cancers have similar prognoses.
The incidence of liver cirrhosis is increasing, especially among women. Epidemic alcoholism is the most important cause, but demographic change is increasing the number of cases of imported liver disease, notably chronic hepatitis B and C.
Cirrhosis should be an active subject of public and political concern, but there is lack of understanding about the disease, and a popular tendency to dismiss warnings about alcohol.
Make no mistake. Cirrhosis is deadly, and a foul way to go. The occasional patient can be rescued by liver transplant, but the opportunities for this dramatic intervention are few.
Cirrhosis is a process which destroys normal liver structure and function. Sustained or repeated injury to the liver lights up a chronic inflammation, which progressively damages and destroys liver cells. Fibrous scars develop in the liver substance. The injury also damages the liver's normal regeneration and repair mechanisms, so that abnormal nodules of liver cells begin to replace surviving normal liver tissues.
These nodules fail to link properly into liver blood and bile systems: the nodular cells cannot provide normal liver function.
Eventually the smooth normal liver is replaced by a nodular scarred mass, essentially a fibrous conglomerate of benign liver tumours.
Cirrhosis, once started, tends to progress remorselessly: stopping drinking has little effect.
The blood supply of the liver is unusual. Blood coming from the intestines, spleen and pancreas is intercepted by the liver, for processing before release into the general circulation. The veins from intestines, spleen and the pancreas join to form the portal vein, which then branches into the liver. There is an arterial supply, the hepatic artery, but this is relatively small.
Total blood flow through the liver at rest is about one quarter of cardiac output, approximately equal to blood flow through the brain.
What is the function of the liver? This was a favourite question to students, and few indeed were the occasions when the answer was satisfactory.
The liver is a gland secreting two fluids.
Bile is the first: a liquid secreted through the bile duct into the duodenum. It is the pathway for the excretion of bilirubin, a breakdown product of haemoglobin. Bile also assists digestion, providing the detergent bile acids, phospholipids and cholesterol needed, especially for the absorption of fats.
Blood plasma is the second secretion of the liver, and by far the most important.
Blood is the product of three organs: bone marrow and lymphatics supply the cellular components; the kidney regulates water and mineral balance; the liver synthesises and controls the complex array of organic molecules which make up the plasma - glucose, albumin, blood clotting factors and so on.
The liver is the custodian of the constancy of the internal environment, the condition for free life, independent of the environment.
If the body is an engine, the liver is the carburettor.
Liver function ensures that the blood has a constant composition: the concentrations of plasma components are controlled within strict limits. It synthesises as necessary, stores and releases glucose and other nutrients, and removes wastes and foreign substances.
Liver function maintains the plasma volume, by regulating the synthesis and plasma concentration of albumin.
The liver is the main source of body heat at rest: its intense metabolism produces heat. It is notably hot to the touch, and blood leaving the liver is the hottest in the body, commonly at least one centigrade degree above the body temperature.
The liver has defence functions too - trapping and destroying bacteria and foreign materials in the blood from the intestines.
Liver, kidney and bone marrow function must be closely co-ordinated. These interactions are poorly understood, but their failure in liver disease has important clinical consequences.
The liver has a huge functional reserve: probably 90% of liver function may be lost before clinical problems begin.
The syndrome of liver failure has three main parts.
Jaundice is the first: accumulation of bilirubin in the blood. This is disfiguring, but does little to impair health otherwise.
The second is nephropathy: impaired kidney function. The patient cannot excrete salt and water adequately. Daily urine volume falls, and sodium excretion may be less than a tenth of normal. The normal urinary excess of sodium over potassium is reversed.
Oedema develops, especially of the lower parts - feet, legs, abdomen. There is likely also to be fluid accumulating in the abdomen - ascites.
This retention of water dilutes the plasma: thus the concentration of albumin falls, but the total body albumin pool is normal or even increased.
In some way the liver drives kidney water and salt excretion. The mechanism of this interaction is not clear.
The third is encephalopathy - disturbance of brain function. In the early stages this causes apathy, loss or reversal of diurnal rhythms, loss of social inhibitions, poor spatial discrimination, and other neuro-psychiatric changes. 'Flapping tremor' is a transient, abrupt loss of posture of the out-stretched hands, with instant recovery. It occurs in other metabolic brain diseases.
Stupor leading to coma is the final state of liver failure. Once established, coma is difficult to reverse and the prognosis is poor.
Fetor is common in liver failure - an unpleasant smell to the breath, like bad meat. It is caused by the excretion of methylated sulphur compounds into the inspired air.
Liver failure is one mode of death in cirrhosis. There are at least two more.
Blood flow through a cirrhotic liver is impeded. Pressure increases in the portal vein, and venous pathways bypassing the liver open up. Eventually varicose veins develop, notably in the lower oesophagus, but also in the rectum and round the umbilicus. These are points where the portal and systemic circulations meet.
Oesophageal varices are large, thin-walled veins, carrying a big flow of blood. They rupture easily, causing severe bleeding into the oesophagus, and so massive vomiting of blood. This dangerous catastrophe is difficult to manage. Varices can be blocked by endoscopic injections of sclerosing substances, when they are not bleeding. Occasionally other interventions are possible.
No one who has witnessed a patient dying in a bed-full of blood will ever doubt the dreadful consequences of cirrhosis.
Finally, malignancy may develop in a cirrhotic liver. Usually a sudden deterioration raises suspicion. Sometimes a blood test can confirm the diagnosis, but the diagnosis may be made only at post-mortem. Malignant change is untreatable and likely to be rapidly fatal.
Never risk cirrhosis. Heed warnings about safe drinking; immunise against hepatitis; practise safe sex - hepatitis is transmitted venereally.
Cirrhosis is as lethal as cancer.