11.6 : Chronic Pancreatitis I: Introduction

The pancreas, an elongated and flat gland situated behind the stomach, serves a vital function in digesting food and managing blood sugar levels.

Pancreatitis is the inflammation of the pancreas, which occurs when the immune system becomes active and causes swelling, pain, and disruptions in organ function. Pancreatitis can manifest as either an acute or chronic condition.

Acute pancreatitis arises suddenly and lasts for a brief duration, while chronic pancreatitis is a long-term affliction that progressively worsens the pancreatic damage over time.

The pathophysiology begins with factors such as chronic alcohol abuse, autoimmune disorders, genetic factors, pancreatic duct obstruction, hypertriglyceridemia, hypercalcemia, and pancreatic cancer.

The pathophysiology of chronic pancreatitis involves a multifaceted interplay of various factors. Let's examine each step in detail and then closely examine the sequence of events.

1. Chronic alcohol consumption can activate pancreatic stellate cells, leading to inflammation and fibrosis.
2. Autoimmune Disorders: Conditions like autoimmune pancreatitis involve the immune system mistakenly attacking the pancreas.
3. Genetic Predisposition: Certain genetic factors, such as susceptibility to pancreatitis, mutations, or variations in specific genes, can increase the development of this condition.
4. Pancreatic Duct Obstruction: Obstruction of the pancreatic duct, which can occur due to factors like gallstones or tumors, leads to a backup of digestive enzymes within the pancreas. This backup contributes to inflammation and tissue damage.
5. Hypertriglyceridemia: Increased blood triglyceride levels can be associated with chronic pancreatitis. High triglycerides may lead to fat accumulation within the pancreas, causing inflammation.
6. Hypercalcemia: Excess calcium levels in the blood can contribute to forming pancreatic stones, leading to ductal obstruction and inflammation.
7. Pancreatic Cancer: In some cases, chronic pancreatitis may be a consequence of pancreatic cancer. The cancer itself or its treatment can contribute to the inflammatory process.

Due to one or more etiological factors, persistent inflammation evolves into fibrosis, involving the deposition of collagen and extracellular matrix components like fibronectin, laminin, and proteoglycans. Fibrosis disrupts the pancreatic architecture, causing narrowing and obstruction of pancreatic ducts, affecting both exocrine and endocrine functions.

Chronic pancreatitis often manifests as abdominal pain, sometimes intermittent, other times near-constant. The pain is typically described as heavy, gnawing, burning, cramp-like, and unaffected by food or antacids. Other symptoms include malabsorption, weight loss, constipation, mild jaundice, steatorrhea, and diabetes, highlighting the significant impacts this condition can have on a patient's overall well-being.

The disease can also result in complications, such as pseudocyst formation, bile duct or duodenal obstruction, pancreatic ascites or pleural effusion, splenic vein thrombosis, pseudoaneurysms, and pancreatic cancer.