• Clinical science

Chronic pancreatitis

Summary

Chronic pancreatitis is caused by progressive inflammation and irreversible damage to the structure and function (exocrine and endocrine) of the pancreas. Alcohol abuse is the most common known etiological factor, followed by pancreatic ductal obstruction. Idiopathic pancreatitis accounts for up to 30% of cases. Patients may be asymptomatic or present with abdominal pain and features of pancreatic enzyme insufficiency (e.g., steatorrhea, weight loss, impaired glucose tolerance). Diagnosis is confirmed on imaging, which demonstrates pancreatic calcifications, ductal strictures, and ductal dilations. Pancreatic function tests (e.g., fecal elastase-1 measurement, 72-hour fecal fat estimation) assess the degree of enzyme deficiency. Symptomatic patients are successfully managed with oral pancreatic enzyme replacements and analgesics. Patients with chronic pain require additional interventions (e.g., celiac ganglion block, partial/complete pancreatic resection).

Etiology

References:[1][2][3][4]

Pathophysiology

References:[1][5]

Clinical features

  • Epigastric abdominal pain (main symptom)
    • Pain radiates to the back, is relieved on bending forwards and exacerbated after eating
    • Pain is initially episodic and becomes persistent as the disease progresses
    • Often associated with nausea and vomiting
  • Features of pancreatic insufficiency
    • Late manifestation (after 90% of the pancreatic parenchyma is destroyed)
    • Steatorrhea (exocrine hormone deficiency)
      • Cramping abdominal pain, bloating, diarrhea, weight loss
      • May cause fat-soluble vitamin deficiencies (A, D, E, and K)
    • Malabsorption and weight loss
    • Pancreatic diabetes (endocrine hormone deficiency)

In the later stages of chronic pancreatitis, patients may not experience any pain!
References:[1][2][6]

Diagnostics

Imaging

  • Abdominal CT (plain and contrast-enhanced): best initial imaging modality to screen for CP
    • Findings: pancreatic atrophy, pancreatic ductal dilations; pancreatic ductal calcifications on plain CT (more sensitive than x-ray); chain of lakes” appearance
    • Can simultaneously rule out a pancreatic carcinoma or a gastrointestinal malignancy as a possible cause of epigastric pain and weight loss
  • MRCP: indicated when CT findings are equivocal but clinical suspicion of CP is high
    • Findings: ductal strictures and dilations, pancreatic calcifications
  • Abdominal x-ray: visible pancreatic calcifications (highly specific, but only seen in ∼ 30% of cases)
  • Ultrasound
    • Abdominal ultrasound: indistinct margins and enlargement; pancreatic calcifications; ductal strictures, dilation or stones
    • Endoscopic ultrasound: parenchymal lobularity and hyperechoic foci; ductal dilation and calcification
  • ERCP: detection of early pathologies and simultaneous treatment possible (e.g., duct dilation, stent insertion)
    • Ductal stones, seen as filling defects
    • Chain of lakes” or “string of pearls” appearance (characteristic feature)
    • Irregularity, dilation of the main pancreatic duct

Laboratory tests

Genetic testing

  • Indication: family history of chronic pancreatitis; young patients with idiopathic pancreatitis
  • PRSS-1 mutations: diagnostic of hereditary pancreatitis
  • CFTR gene: 40% of patients with idiopathic chronic pancreatitis have a CFTR gene mutation.

References:[1][7][8][9][10][11]

Treatment

General measures

  • Abstinence from alcohol and nicotine
  • Small, regular meals (rich in carbohydrates, low in fat), supplementation with medium-chain triglycerides (MCT)
  • Pancreatic enzyme replacement (with meals)
  • Parenteral administration of fat-soluble vitamins (A, D, E, K) if necessary
  • Endocrine insufficiency: Insulin administration
  • For management of acute attacks see “Treatment” in acute pancreatitis.

Pain management

Surgery

References:[1][12][13]

Complications

Pancreatic pseudocysts

  • Definition: encapsulated collection of pancreatic fluid; which develops 4 weeks after an acute attack of pancreatitis; can occur in both acute and chronic pancreatitis
  • Pathophysiology: pancreatic secretions leak from damaged ducts → inflammatory reaction of surrounding tissue → encapsulation of secretions by granulation tissue
  • Clinical features
    • Often asymptomatic
    • Painless abdominal mass
    • Pressure effects
  • Diagnostics: abdominal ultrasound/CT/MRIextrapancreatic fluid collection within well-defined wall/capsule, no solid cyst components detectable
  • Treatment: : Surgical/endoscopic cystogastrostomy/cystoduodenostomy/cystojejunostomy ; ultrasound/CT-guided percutaneous drainage
  • Complications

Splenic vein thrombosis

  • Can occur in 10% of patients with chronic pancreatitis
  • Pathophysiology: inflammation of the splenic vein thrombus formation → left-sided portal hypertensiongastric varices
  • Clinical features: can present with upper GI bleeding, ascites, and splenomegaly
  • Diagnosis: ultrasound with doppler, CT/MR angiography
  • Treatment
    • Acute: anticoagulation and/or thrombectomy
    • Chronic and symptomatic: splenectomy

Pancreatic ascites

  • Pathophysiology: Ductal disruption (due to an acute attack of pancreatitis; pancreatic surgery/trauma) or a pseudocyst leak/rupturepancreatic ascites
  • Clinical features
    • Abdominal distension; variable abdominal pain; dyspnea ; peripheral edema
    • Free fluid in the peritoneal cavity
  • Diagnosis
    • Ascitic fluid analysis: Exudate with high amylase levels (> 1000 IU/L)
    • ERCP: Demonstrates the site(s) of leak
    • CECT and MRCP can also demonstrate ascites and the site of leak; ERCP is preferred since treatment can be performed in the same sitting
  • Treatment

Further complications

References:[14][15][16][17][6][1]

We list the most important complications. The selection is not exhaustive.