Chronic Pancreatitis

Background

• Chronic pancreatitis is a progressive disorder of the pancreas from continuous or episodic inflammation resulting in destruction of pancreatic secretory cells leading to progressive failure of exocrine and endocrine pancreatic function.
• Chronic pancreatitis typically presents with chronic abdominal pain or is a result of recurrent episodes of acute pancreatitis which may have superimposed flares. Chronic pancreatitis may also present with signs and symptoms of exocrine pancreatic insufficiency such as steatorrhea and malnutrition, as well as diabetes or jaundice.
• Chronic pancreatitis is uncommon (prevalence ranging from 13 to 125 per 100,000 people).
• Causes of chronic pancreatitis include high alcohol use, smoking, recurrent acute pancreatitis, ductal injury or obstruction, immunoglobulin G4 (IgG4)-related disease (autoimmune pancreatitis), metabolic imbalances, cationic trypsinogen gene mutation and other genetic etiologies, and, rarely, infection. In many cases the cause cannot be determined, labeling these disorders as idiopathic.
• Common complications include diabetes mellitus, exocrine pancreatic insufficiency with fat soluble vitamin and micronutrient deficiencies, osteoporosis or osteopenia, low trauma fracture, pancreatic cancer, pseudocyst formation, maldigestion, pancreatic or biliary duct strictures, and duodenal stenosis.

Evaluation

• Suspect chronic pancreatitis in patients with constant or postprandial epigastric abdominal pain (most common presentation), nausea and vomiting, abdominal distention, steatorrhea, recurrent acute pancreatitis, or complications of pancreatitis.
• Confirm the diagnosis with imaging and pancreatic function tests
  • The best imaging modalities are endoscopic ultrasound, magnetic resonance imaging, or computed tomography.
  • Endoscopic retrograde cholangiopancreatography (ERCP) is no longer considered an appropriate diagnostic test due to higher risk for adverse events and should be reserved only for therapeutic interventions.
  • Perform non-invasive pancreatic function test with fecal elastase-1 (FE-1) or 13C mixed triglyceride breath test (Strong recommendation).
• Identifying causes of chronic pancreatitis
  • Rule out cystic fibrosis in patients < 20 years old and in patients of any age without an identifiable etiology (Strong recommendation).
  • Assess for autoimmune pancreatitis in patients without an identifiable etiology (Weak recommendation).
  • Multigene panel testing in those without an identifiable etiology.
• If chronic pancreatitis is confirmed, obtain blood tests and other testing to thoroughly assess for pancreatic and extra-pancreatic complications, including exocrine pancreatic insufficiency and diabetes mellitus (Strong recommendation).
• Consider endoscopic ultrasound (EUS) to screen for pancreatic cancer (Weak recommendation).

Management

• Advise lifestyle changes.
  • Encourage avoiding smoking and avoiding alcohol use regardless of chronic pancreatitis etiology.
  • Diet
    • Obtain individualized dietary counseling from an experienced dietician to improve nutritional status (Strong recommendation).
    • If well-nourished, follow normal healthy eating advice (Strong recommendation).
    • Avoid dietary fat restriction and very high fiber diet (Strong recommendation).
    • If malnourished, consider small, frequent, high-energy meals (Weak recommendation).
    • Consider screening for fat soluble vitamin and micronutrient deficiencies (Weak recommendation), and supplement as needed. (Strong recommendation).
• Medication management
  • Prescribe analgesics as needed
    • Avoid non-steroidal anti-inflammatory drugs (NSAIDs) due to possible gastrointestinal adverse events.
    • Consider nerve blocks.
    • Minimize the use of opioid analgesics whenever possible
  • Pancreatic enzyme replacement therapy (PERT)
    • PERT is indicated for patients with exocrine pancreatic insufficiency and clinical symptoms or laboratory signs of maldigestion following appropriate nutritional evaluation (Strong recommendation).
    • Take PERT with meals and snacks (Strong recommendation).
      • Start with lipase dose > 40,000 units with main meals, and about half that with snacks (Strong recommendation). Lower doses (25,000-40,000 units per meal) may be effective in some patients, but most patients will require higher doses.
      • PERT preparations of choice are enteric-coated microspheres or mini-microspheres < 2 mm diameter (Strong recommendation).
  • Corticosteroids (equivalent prednisone dosing 30-40 mg/day for 3-4 weeks) are indicated for autoimmune pancreatitis. See also Autoimmune Pancreatitis
• Consider endoscopic or surgical intervention if inadequate symptom relief from less invasive therapies.
  • Endoscopic therapy options may be used in several clinical scenarios
    • To address intraductal stones or ductal hypertension, consider procedural interventions including extracorporeal shock wave lithotripsy, stone extraction via basket or balloon, or sphincterotomy for decompression.
    • For main pancreatic duct or common bile duct strictures, consider stenting and/or dilation.
    • For pancreatic pseudocysts, consider endoscopic drainage with stents or ultrasound-guided drainage .
  • Surgical therapies aim to increase drainage or resect portions of the pancreas to achieve decompression.
    • Drainage procedures generally involve anastomosis of the main pancreatic duct to the jejunum. Commonly used options include lateral pancreaticojejunostomy (modified Puestow procedure) and the Frey procedure (mixed drainage and resection technique).
    • Resection options include
      • longitudinal V-shaped excision of ventral pancreas combined with longitudinal pancreaticojejunostomy.
      • distal pancreatectomy if disease confined to tail of pancreas.
      • duodenum-preserving pancreatic head resection (DPPHR) (including Beger, Berne, and Frey procedures)
      • pancreaticoduodenectomy (Whipple procedure).
      • total pancreatectomy.
      • total pancreatectomy with islet-cell auto-transplantation (TPIAT) which is a potential option in patients with recurrent acute or chronic pancreatitis with preserved islet cell function to decrease the risk of post-operative diabetes mellitus and brittle diabetes mellitus
  • See Procedural interventions for chronic pancreatitis topic for additional information.
• Follow-up
  • Obtain pancreatic function tests to assess for exocrine pancreatic insufficiency annually (to detect maldigestion before clinical symptoms) or if symptoms develop or if there is a suspicion of exocrine insufficiency (Strong recommendation).
  • Pay close attention to patients with chronic pancreatitis, diabetes, pancreatic carcinoma, pancreatic resection, or gastric resection (or prior gastric surgery including Roux-en-Y gastric bypass) due to increased risk of development of exocrine pancreatic insufficiency (Strong recommendation).
  • To reduce risk of developing or exacerbating bone-related complications (Strong recommendation):
    • Encourage basic preventative measures in all patients, such as adequate diet including calcium and vitamin D intake, regular weight-bearing exercise, and avoiding smoking and alcohol intake.
    • For patients with osteopenia, assess bone density by dual-energy X-ray absorptiometry (DEXA) every 2 years.
  • Screen for diabetes with fasting plasma glucose and HbA1c levels annually even if no clinical symptoms (Strong recommendation).
  • Consider surveillance for pancreatic cancer with endoscopic ultrasound (EUS) or dedicated cross-sectional (MRI or CT) imaging on a regular basis (Weak recommendation).