Acute pancreatitis

Pathogenesis and biochemical aspects

Normally, the pancreas produces a wide range of digestive enzymes. Initially, they are synthesized in the form of inactive precursors — proenzymes. Their activation should occur only under the influence of physiological stimuli and strictly outside the organ itself.

When an inflammatory process occurs, tissue edema develops. This inevitably leads to a reduction in the lumen of the pancreatic excretory duct. As a result, pronounced stasis of pancreatic juice is formed. The main danger of obstructed secretion outflow is that proenzymes begin to activate prematurely directly within the pancreatic parenchyma. A severe pathogenetic mechanism is triggered — autolysis (self-digestion of tissue by its own enzymes).

Classification and morphological changes

The disease is classified according to the nature and severity of tissue lesions. According to the International Classification of Diseases (ICD-10, code K85), there are several main forms reflecting the sequential stages of the pathological process (from a relatively mild course to destructive changes):

• Acute pancreatic edema (interstitial form) is the initial stage of the lesion.
• Fat necrosis (steatonecrosis) is the stage of fat cell death.
• Hemorrhagic pancreatitis is a severe form accompanied by hemorrhages into the affected tissue.
• Purulent pancreatitis is the extreme degree of destruction with the formation of a purulent focus.

The role of infections in etiology

Infectious agents act as one of the etiological factors in the development of the inflammatory process. Both viral and bacterial microorganisms play a role in the pathogenesis of the disease.

• Viral agents: An important pathogen is the mumps virus, which has an extremely high tropism for glandular tissue. In addition, enteroviruses (e.g., Coxsackie viruses) can provoke inflammation.
• Bacterial agents: The inflammatory process can be initiated by staphylococci, as well as specific causative agents of dysentery (Shigella).

Specific complications: pancreatic ascariasis

A specific cause of inflammation can be the mechanical migration of Ascaris worms into the pancreatic duct. The presence of the parasite leads to severe consequences: inflammation develops resembling chronic indurative or acute pancreatitis (including its hemorrhagic form).

Treatment in this situation is exclusively surgical. The patient undergoes pancreatotomy with the physical removal of the parasite from the ductal system. The most important stage is the postoperative period, during which mandatory drug deworming is performed.

Surgical risks of concomitant ascariasis

Ascaris worms can affect not only the pancreas, but also the bile ducts and the gastrointestinal tract. Biliary tract involvement has no pathognomonic signs, but presents with clinical features of obstructive jaundice, purulent cholangitis, or liver abscess (diagnosed via ultrasound, CT, and retrograde cholangiography). The disease is characterized by acute onset, rapid progression, and severe intoxication. Surgical treatment in this case includes cholecystectomy, choledochotomy with worm removal, external drainage of the biliary tract, as well as opening and drainage of the liver abscess.

Any surgery can provoke active migration of Ascaris, which threatens severe postoperative complications:

1. If parasites are eliminated with vomitus, they may enter the respiratory tract, leading to mechanical asphyxia.
2. Worms may emerge into the free abdominal cavity through suture lines (if hollow organ lumens were opened), leading to the development of purulent peritonitis. A similar clinical picture of purulent peritonitis occurs with perforation of gastrointestinal organs (esophagus, stomach, or intestines) against the background of pathological wall changes (ulcer, mucosal necrosis).

Given the severity of such complications, stool tests for helminth eggs are indicated for absolutely all patients prior to elective surgery, and pre-operative deworming if they are detected.

Class and exam questions

What else to study on this topic

• Enzyme composition and physiological mechanisms of pancreatic proenzyme activation.
• Retrograde cholangiography and other diagnostic methods for surgical complications of ascariasis.
• Mechanisms of formation and clinical picture of parasitic liver abscesses.
• Pathogenesis and clinical presentation of purulent peritonitis in perforation of gastrointestinal hollow organs.

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Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.