13. Pathophysiology of chronic pancreatitis
Chronic pancreatitis is the slow, progressive and irreversible destruction of the pancreas. People suffering from it occasionally have exacerbations. It rarely evolves from an acute pancreatitis.
Etiology
The common causes include:
- Chronic alcoholism – more viscous juice, less antitrypsin, increased sphincter tone
- Idiopathic, especially in elderly
- Cystic fibrosis – mucoviscidosis. more viscous juice
- Chronic protein deficiency
- Chronic hypercalcaemia – due to crystal precipitating in the ducts
- Compression of ducts – tumor, scarring and cysts causing prolonged and repeated occlusions
- Smoking
- States of prolonged hypersecretion: overproduction of gastrin, secretin, CCK,VIP or defective removal (cirrhosis)
No matter the cause does the pathogenesis involve a gradual fibrosis of the pancreatic parenchyme.
Clinical features
The three common consequences are:
- Epigastric belt-like pain
- Complex malabsorption syndrome
- Secondary diabetes mellitus
Pathomechanism
It appears that the pathomechanism of chronic pancreatitis is similar to that of the acute type except to a less severe degree. The more viscous juice partly obstructs the duct, causing some enzymes to be forced into the parenchyme where they cause damage. The damage is healed by fibrosis, which further narrows the ducts. This process will eventually reduce the number of functioning acini, causing pancreatic juice deficiency and resulting complex malabsorption.
The pain comes from the fact that the fibrosis compresses nerve endings in the pancreas.
The process also damages the Langerhans islets, eventually causing “secondary” pancreoprivic diabetes. In this case is also glucagon deficient.
Treatment
The progression of the disease can be slowed. This is accomplished by preventing unnecessary pancreatic secretion, meaning that the patient should consume small, frequent meals of easily digestible food. If necessary should insulin be administered. Alcohol-abstinence is essential.