chronic pancreatitis

Etiology

(also see causes of acute pancreatitis)

• alcoholism: > 75 gm ETOH/day for > 5-15 years
• smoking is an independent risk factor
• uncommon causes
  • idiopathic
  • obstruction
    • tumor
    • trauma (pancreatic duct stricture)
    • pancreas divisum
  • hereditary (see genetics)
  • tropical: nutritional deficiencies
  • hyperlipidemia
  • hypercalcemia, hyperparathyroidism
  • fibrocystic disease of the pancreas
  • recurrent acute pancreatitis
  • autoimmune pancreatitis
  • chronic renal failure
  • vascular disease, ischemia

Pathology

• pancreatic duct obstruction by precipitated proteins
• calcification of protein plugs
• recurrent or severe necrotizing acute pancreatitis may result in deposition of collagen & chronic pancreatitis
• pancreatic ascites may occur

Genetics

• hereditary chronic pancreatitis associated with mutations in PRSS1 (trypsin-1)
• genetic variations in chymotrypsin C (CTRC) can predispose to chronic pancreatitis by diminishing its protective trypsin-degrading activity
• mutations in cationic trypsinogen gene
• defects in SPINK1 are a cause of chronic pancreatitis
• defects in CFTR predispose to chronic pancreatitis
• deficiency of lithostatin may predispose
• defects in calcium sensing receptor (CaSR)
• defects in claudin-2 (CLDN2)

Clinical manifestations

• abdominal pain
  • recurrent episodes of abdominal pain
  • epigastric pain & tenderness
  • often radiating to back
  • duration: hours to days
  • often precipitated by EtOH
  • many patients transition between continuous pain, intermittent pain, & no pain
    • patients with continuous pain report worse quality of life
• malabsorption
  • pancreatic exocrine insufficiency
  • steatorrhea when > 90% of pancreas has been destroyed
  • malnutrition, poor eating habits
  • weight loss
  • osteopenia, osteoporosis
• diabetes mellitus
  • late manifestation
  • brittle in nature
  • hypoglycemic episodes may be fatal
• other complications
  • obstructive jaundice
  • pancreatic pseudocyst
  • ascites
  • pleural effusion
  • gastrointestinal bleeding
    • peptic ulcer
    • esophageal varices
  • adenocarcinoma of the pancreas

Laboratory

• blood tests are not useful, amylase & lipase are elevated only during acute exacerbations & diminish with diminishing residual functional pancreatic tissue
• ancillary biochemical studies
  • Chymex (bentiromide) test
  • fecal fat
  • fecal chymotrypsin
  • fecal elastase
• sweat test for cystic fibrosis (young adults)
• genetic testing for familial pancreatitis
  • PCR/southern blot for cystic fibrosis (young adults)
• serum IgG4 (older patients to exclude autoimmune pancreatitis)
• see ARUP consult

Diagnostic procedures

• secretin stimulation test
  • duodenal aspiration after IV secretin administration
  • estimate bicarbonate excretion by pancreas
  • most sensitive test, but not practical
• endoscopic retrograde cholangiopancreatography (ERCP) not indicated for diagnosis
• endoscopic ultrasonography
• pancreatic biopsy not indicated for diagnosis

Radiology

• plain film of the abdomen (KUB)
  • pancreatic calcifications may be seen
  • ductal & parenchymal changes
• pancreatic protocol computed tomography (CT) of abdomen
  • pancreatic pseudocysts
  • ductal dilatation
  • pancreatic calcium deposits
  • parenchymal atrophy
• MRI or MRCP

Complications

• increased incidence of carcinoma of the pancreas
• increased incidence of other malignancies
  • lung
  • esophagus
  • oral cavity
• pancreatic pseudocysts, +/- vascular aneurysms
• bile duct obstruction, gastric outlet obstruction
• portal hypertension, ascites

Management

• abstinence from alcohol & tobacco
• analgesia to relieve pain
  • non-narcotic analgesics
    • pregabalin may be useful for idiopathic chronic pancreatitis
  • opiates
  • celiac plexus block (short-duration effect)
  • intrathecal anesthesia (investigational)
  • thorascopic splanchnicectomy (investigational)
• low-fat diet
• pancreatic enzyme replacement
  • 1st line to control diarrhea
  • pancrelipase (Viokase, Pancrease, Cotazym, Ku-Zyme) 1-3 tabs PO with meals
• medium-chain triglycerides for steatorrhea & calorie malnutrition
• loperamide or Lomotil may be useful for persistent diarrhea
  • avoid opiates
• insulin for diabetes
  • small doses
  • frequent interval dosing
  • diabetes may be brittle; hypoglycemia may occur
  • error on the side of hyperglycemia
• octreotide 200 ug SQ TID is recommended by some
• endoscopy
  • ERCP with pancreatic sphincterotomy, stone removal, stricture dilation, stent therapy
  • placement of long multiholed stent into the pancreatic duct to facilitate drainage of pancreatic secretions
  • transpapillary drainage of cyst into stomach or duodenum
• angiography & embolization of vascular aneurysms that develop with pseudocysts
• surgery
  • surgical decompression of pancreatic ductal strictures
    • lateral pancreaticojejunostomy
  • pancreatectomy vs pancreatoduodenectomy as a last resort for intractable pain
  • early surgery may provide pain relief in 58% of patients
    • decompression with drainage, pancreatic resection, or denervation of celiac ganglion & splancnic nerves
    • pain relief somewhat better with surgery than endoscopy at 18 months
  • age alone should not preclude a pancreatic resection
• antioxidant cocktail daily may diminish abdominal pain
  • selenium 600 ug
  • ascorbic acid 540 mg
  • beta carotene 9000 IU
  • tocopherol 270 IU
  • methionine 2 g daily
• antioxidants do not reduce pain in chronic pancreatitis

More general terms

• pancreatitis
• chronic inflammation

More specific terms

• autoimmune pancreatitis; lymphoplasmocytic sclerosing pancreatitis
• tropical calcific pancreatitis

Additional terms

• acute pancreatitis
• pancreatic ascites
• pancreatic pseudocyst

Patient information

chronic pancreatitis patient information

Database

• OMIM: https://mirror.omim.org/entry/167800