What is the pancreas?
|Treatment is directed towards preventing attacks, controlling the pain and treating the complications.|
The pancreas is an elongated gland situated at the back of the upper abdominal cavity behind the stomach.
It's divided into the head (through which the common bile duct runs as it enters the duodenum from the liver) and the body (which extends across the spine) and the tail.
The tail of the pancreas is close to the left kidney and to the spleen. Because the pancreas lies at the back of the abdominal cavity, diseases of the pancreas may be difficult to diagnose.
What does the pancreas do?
The pancreas has two main functions.
- An exocrine function into the gut producing a series of enzymes, which help in the digestion of food. Enzymes produced in the pancreas are important in the digestion of proteins, carbohydrates and, particularly, fats. Bicarbonate is also produced in large amounts to neutralise the acid produced by the stomach.
- An endocrine function into the blood producing a series of hormones, which are important in maintaining a normal level of sugar in the blood. The best known of these hormones is insulin. Insulin deficiency of this hormone results in the development of insulin dependent diabetes mellitus (IDDM). Another hormone (glucagon) helps to raise blood sugar, and several other hormones control intestinal function.
What is pancreatitis?
Any inflammation of the pancreas is called pancreatitis.
Acute pancreatitis results in severe inflammation of the gland. Patients may be seriously unwell.
Chronic pancreatitis develops either as the result of repeated attacks of acute pancreatitis or as the result of other injuries to the pancreas (see below).
However, occasionally chronic pancreatitis can occur with no previous problems or symptoms and may be related to certain genetic mutations.
It's thought that the damage to the pancreas occurs as the result of digestive enzymes leaking into the pancreas and starting to digest it. This sets up inflammation, and when the inflammation settles, the scarring process distorts the pancreas making further attacks of inflammation likely. Thus a vicious cycle develops.
As a result of prolonged damage to the pancreas, the pancreas fails to produce enough digestive enzymes to permit adequate digestion of food particularly fat which is difficult to absorb.
This leads to weight loss and the frequent passage of pale greasy stools which contain excess amounts of fat.
Further, the destruction of the cells which produce insulin may lead to the development of diabetes.
What causes chronic pancreatitis?
The most common cause of chronic pancreatitis is long-term excessive alcohol consumption.
There's a direct relationship between the amount of alcohol consumed and the risk of developing chronic pancreatitis.
Other causes include:
- repeated attacks of pancreatitis associated with gallstones
- high levels of calcium in the blood
- abnormalities in anatomy which are usually present at birth
- cystic fibrosis
- high blood fats (hypertriglyceridaemia)
- in rare cases, some drugs can cause pancreatitis
- in a number of cases no specific cause can be identified, a condition known as idiopathic pancreatitis.
What are the symptoms of chronic pancreatitis?
The symptoms are very variable.
Pain occurs in most patients at some stage of the disease. This may vary in intensity from mild to severe. It may last for hours or sometimes days at a time and may require strong painkillers to control it.
It often radiates through to the back and can sometimes be relieved by crouching forward. It is commonly brought on by food consumption and so patients may be afraid to eat. It is also commonly severe through the night.
The pain varies in nature, being gnawing, stabbing, aching or burning, but it tends to be constant and not to come and go in waves. It may sometimes burn itself out but can remain an ongoing problem.
The pain is often difficult to diagnose and can be mistaken for pain caused by virtually any other condition arising from the abdomen or lower chest.
A particular problem is differentiating chronic pancreatitis from pancreatic cancer.
Diabetes is also a common symptom which affects over half of all patients with long-standing chronic pancreatitis.
Long-standing chronic inflammation results in scarring of the pancreas which destroys the specialised areas of the pancreas, which produce insulin.
Deficiency of insulin results in diabetes.
Diarrhoea occurs in just under half of patients. Normally, all the fat in food is broken down by enzymes from the pancreas and small intestine, and the fat is then absorbed in the small bowel.
With a reduced level of digestive enzymes the fat is not absorbed.
When the fat reaches the large intestine, it is partially broken down by the bacteria in the colon.
This produces substances which irritate the colon and result in diarrhoea.
The undigested fat also traps water in the faeces, resulting in pale, bulky, greasy stools which are difficult to flush away. They may make the water in the toilet look oily, smell offensive and may be associated with bad wind.
Weight loss occurs in virtually all patients with chronic pancreatitis.
It is due to failure to absorb calories from food, and diabetes may also contribute to this.
In addition, patients may be afraid to eat because eating brings on the pain.
Jaundice (when patients develop yellow eyes and skin) occurs in about a third of patients with chronic pancreatitis. It is usually due to damage to the common bile duct which drains bile from the liver to the duodenum.
The common bile duct normally passes though the head of the pancreas. In long-standing chronic pancreatitis, the scarring in the head of the pancreas narrows the common bile duct.
Some degree of narrowing may occur in up to half the patients with chronic pancreatitis but when the narrowing is severe, it prevents the bile draining from the liver into the duodenum. It then spills back into the blood and the patient's eyes and skin become yellow. In addition, the stools become paler (since bile makes the stools brown) and the urine becomes dark (because it contains more bile than normal).
The development of jaundice in any patient with chronic pancreatitis is a serious sign and requires urgent investigation (abdominal ultrasound or CT scan) to exclude a pancreatic cancer.
Vitamin and mineral deficiency: prolonged passage of stools containing fat can result in low levels of calcium and magnesium in the blood. In addition, some vitamins may not be absorbed properly. This includes vitamins A, D, E and K.
How is pancreatitis diagnosed?
Chronic pancreatitis often causes no symptoms and may be discovered by accident during the course of investigation of symptoms not related to pancreatitis.
For example, calcification in the pancreas may be seen on an X-ray of the abdomen performed for other reasons.
If your doctor suspects that you have chronic pancreatitis, then the first examination is likely to be an ultrasound scan of the abdomen.
ERCP is usually reserved for cases where therapy is required as ERCP itself can cause pancreatitis.
Ultrasound examination of the abdomen
This type of examination is identical to that performed in pregnant women to assess the growth of the baby.
It uses an ultrasound probe to generate high-frequency sound waves that bounce back from the deep tissues and are detected by the same probe.
It is a very safe technique and is widely used. It is performed by smearing some jelly over the upper abdomen and then moving the ultrasound probe across the skin of the upper abdomen.
However, because the pancreas lies at the back of the abdominal cavity and, therefore, a long way from the transponder, images of the pancreas may be difficult to obtain.
Sometimes the problem is obesity, sometimes the pancreas is obscured by air within the intestines.
Even if the result of the ultrasound examination is normal, this does not rule out the possibility of chronic pancreatitis.
Abdominal CT scanning
The information thus obtained is then analysed by a powerful computer, which then produces 'slices' though the abdomen.
This technique is more reliable in imaging the pancreas than abdominal ultrasound.
However, a normal CT scan does not exclude a diagnosis of chronic pancreatitis, but it's probably the best widely available test.
It has the advantage of being free of serious risk and discomfort.
Abdominal MRI scanning
MRI scanning is a newer technique of examining abdominal organs. It does not involve X-rays.
The patient is passed though a large and powerful magnet which energises molecules within the body tissues. It is harmless, but is very noisy.
Abdominal MRI is currently under evaluation with regard to the accuracy of diagnosis of pancreatic disease.
ERCP (endoscopic retrograde cholangiopancreatography) is a procedure whereby X-ray contrast material is injected into the bile duct and pancreatic duct to allow X-ray pictures to be taken of these ducts.
Under sedation, an endoscope is passed into the duodenum, a small cannula (a very small tube) is inserted into the pancreatic duct and X-ray contrast is injected. X-rays are then taken.
However, ERCP is not routinely used as the first line of investigation in suspected pancreatitis.
There's a very real risk of inducing a further attack of pancreatitis as a result of the irritant effect of the X-ray contrast within the duodenum.
ERCP is likely to be performed if any therapy or treatment is required. Stones can be removed from the pancreatic duct or tubes (stents) can be inserted to drain the pancreas with this procedure.
Analysis of pancreatic juice
In the UK this test is rarely performed outside of research centres.
Endoscopic ultrasound scan (EUS)
Endoscopic ultrasound (EUS) involves mounting a small ultrasound probe like those used on the abdominal wall, onto a special endoscope or tube.
The patient, under sedation, swallows the tube and the probe is pressed directly onto the gastric or duodenal wall close to the pancreas.
This allows much more accurate pictures and helps to separate chronic pancreatitis from pancreatic cancer which can be difficult.
Needles attached to the probe can obtain tissues samples or fluid directly from the pancreas for laboratory analysis.
This technique is increasingly widespread and available and is often used in difficult pancreatic cases.
Analysis of stool
Patients with chronic pancreatitis may present with a particular type of diarrhoea. This is called steatorrhoea.
The stool is typically pale, bulky, offensive and difficult to flush away. In this situation stool is sent for analysis of faecal elastase.
This is an enzyme produced by the pancreas and excreted unchanged in the stool.
A reduction in faecal elastase is treated with pancreatic enzymes in capsules taken with each meal.
Is chronic pancreatitis dangerous?
The major problem with chronic pancreatitis is pain control. The pain of chronic pancreatitis may be constant, severe and long lasting.
There is always the risk of addiction to these drugs, particularly if their use is not controlled.
Chronic pancreatitis is associated with a reduction in life expectancy.
Only half of the patients with a diagnosis of chronic pancreatitis will survive for longer than seven years following diagnosis.
There is also an increased rate of cancer of the pancreas in patients with chronic pancreatitis and this accounts for a fifth of the deaths.
Other causes of death include complications of diabetes and complications from alcoholism.
How is chronic pancreatitis treated?
There is no cure for chronic pancreatitis.
Once the pancreas is damaged, then it is not able to return to normal function and there is always the potential for further attacks.
Treatment is, therefore, directed towards preventing attacks, controlling the pain and treating the complications.
Preventing symptoms worsening
Patients with chronic pancreatitis should avoid alcohol altogether.
If the pancreatitis is due to excess alcohol consumption, then this is essential.
If an underlying cause has been identified then this should be treated. Your doctor may recommend removal of the gall bladder if pancreatitis is thought to be caused by gallstones.
Rare disorders of calcium metabolism and of fat metabolism will be treated appropriately.
If a cause for attacks of pancreatitis can be found this should be treated.
It's vitally important drinking alcohol should be stopped in those patients where it is a factor.
Surgical removal of the gallbladder (cholecystectomy) may be advised for some patients.
Gallstones in the common bile duct between the liver and duodenum can be removed at ERCP.
Occassionally other endoscopic (internal tube) therapy may be used. Cutting the lower end of the bile duct to improve bile flow can reduce attacks of pancreatitis in some patients.
Removal of stones in the pancreatic duct to reduce blockage or insertion of stents to drain the pancreas can be used. These are difficult techniques that are usually performed in centres specialising in the pancreas as results can not be guaranteed and complication are always a risk.
Resting the pancreas by giving pancreatic supplements by mouth, such as Creon, may help reduce attacks of pancreatitis.
Control of pain
This is a very important aspect of the treatment of chronic pancreatitis.
Pancreatic pain varies in severity from mild (controllable with simple analgesics such as paracetamol (eg Panadol)) to severe (requiring morphine-like drugs for control).
In addition to the preventive measures listed above, the basic principle is to use the drug lowest down the analgesic ladder which controls the pain.
Since the pain is often worse at night and since both body and mind are at their lowest ebb in the early hours of the morning, the lowest rung of the analgesic ladder may be pethidine or morphine (eg MST continus tablets).
Since the pain is chronic and severe, there's a fine line between adequate analgesia and addiction.
Newer pain relieving medicines, such as pregabalin, may be more effective for this nerve pain and have fewer side-effects. Risk of addiction is also lower.
Antidepressants may reduce the requirement for pain killers or even help with pain relief themselves.
Antidepressants may also help with the depression, so often associated with chronic pain itself.
Pain management in chronic pancreatitis often requires specialist help.
Most hospitals now have a dedicated pain clinic often run by anaesthetists with particular skills and helped by trained nurses.
Your GP or hospital gastroeneterologist can help with referral to the pain clinic.
As well as maximising the benefit from drug therapy the pain specialists may such blocking the nerves to the pancreas to reduce pain.
It involves the injection of agents via needle into and around the pancreas but requires great skill and careful consideration.
Treatment of the complications
Food malabsoprtion due to lack of pancreas enzymes is treated by giving the same enzymes by mouth in tablet or powder form.
These supplements such as Creon or Pancrex are often sprinkled on food.
A low fat diet is also frequently advised.
Diabetes complicating chronic pancreatitis is treated with a combination of diet, tablets or insulin in the normal way.
Specific complications such as jaundice or pancreatic cysts can be relieved by stenting or by-passing the blockages, but require specialist advice.
Surgery for chronic pancreatitis
In rare cases, it may be necessary to consider surgery as a treatment of chronic pancreatitis.
The indication for surgery is usually severe pain unresponsive to standard measures or a high level of morphine or similar drug usage in a young person.
The surgery may involve measures to improve drainage of the pancreatic duct, partial or complete removal of the pancreas.
The major problem with removal of all or part of the pancreas is that it could lead to the development of diabetes in those patients who don't already have it.
Other people also read:
X-ray: is X-ray radiation dangerous?
Jaundice: how does a person get jaundice?
CT scanning: what are CT scans used for?
Gallstones: who is at risk of developing gallstones?
Diabetes: common symptoms of diabetes
Last updated 13.11.2012