II. Definitions
- Chronic Pancreatitis
- Permanent, progressive Pancreas tissue destruction with secondary dysfunction
III. Epidemiology
- Incidence: 4-12 per 100,000 per year, U.S.
- More common in men (by factor of 1.5-3 fold)
- Age of onset: 35-55 years old
IV. Pathophysiology
- Recurrent episodes of Acute Pancreatitis with exaggerated inflammatory response
- Profibrotic response persists with secondary pancreatic Collagen deposition and fibrosis
- Pain episodes may resolve once pancreatic function fails completely
V. Causes
- Chronic Alcoholism (most common U.S. cause, up to 70% of cases)
- Idiopathic (25% of cases)
-
Autoimmune Pancreatitis (5-6% of cases)
- Inflammatory Bowel Disease
- Sjogren's Syndrome
- Primary biliary Cirrhosis
- Hypertriglyceridemia
- Hyperparathyroidism or Hypercalcemia
- Hemochromatosis
- Hereditary Pancreatitis (most common in children)
- Cystic Fibrosis
- Various Autosomal Dominant and recessive genetic defects
- Occult neoplasm or other causes of pancreatic obstruction
- Chronic Renal Failure
- Medications
- Severe, recurrent Pancreatitis
- Severe acute or recurrent Pancreatitis with Pancreas necrosis
- Post-radiation
- Vascular ischemia
- Anatomic abnormalities
- Sphincter of odi dysfunction
- Pancreas divisum
VI. Symptoms
-
Abdominal Pain (80-90% of cases)
- Chronic, recurrent and disabling Abdominal Pain
- Midepigastric postprandial pain with radiation to the back
- Relieved on sitting upright or leaning forward
- Worse when eating
-
Bowel malabsorption (once only 10% of exocrine function remains)
- Steatorrhea
- Weight loss
- Hyperglycemia (and Diabetes Mellitus)
- Vitamin Deficiency (uncommon)
- Deficiency of Vitamins A,D,E,K
- Vitamin B12 Deficiency
VII. Labs: Standard
-
Pancreatic Enzymes
- Serum Amylase normal
- Serum Lipase normal
- Contrast with at least a 3 fold increase over normal in Acute Pancreatitis
-
Liver Function Tests
- Increased Serum Bilirubin and Alkaline Phosphatase if biliary obstruction present
-
Stool studies (Late findings)
- Steatorrhea (abnormal if fecal fat concentration >9.5% or >7 grams/day)
- Fecal elastase (Abnormal if <200 mcg/gram of stool)
- Serum Electrolytes (including Serum Calcium)
- Evaluate for Hyperparathyroidism (Hypercalcemia)
-
Fasting Glucose (or Hemoglobin A1C)
- Glucose Intolerance or Diabetes Mellitus (50% of patients)
- Serum Lipids
- Evaluate for Hypertriglyceridemia
-
Complete Blood Count
- May suggest infectious cause
- Autoimmune markers (consider)
- IgG4 Serum Antibody
- Antinuclear Antibody (ANA)
- Rheumatoid Factor (RF)
- Erythrocyte Sedimentation Rate (ESR)
- C-Reactive Protein (C-RP)
VIII. Labs: Pancreatic Exocrine Function
- Indications
- Evaluate for pancreatic exocrine insufficiency
- Tests are expensive (and in some cases invasive)
- Not recommended for routine workup
- May be indicated in non-diagnostic evaluation or on specialty Consultation
- Available tests
- Serum trypsinogen
- Abnormal if <20 ng/ml
- Fecal elastase
- Abnormal if <200 mcg/g stool
- High False Positive Rate (Test Sensitivity: >65%, Test Specificity: 55%)
- Fecal fat
- Requires 72 hour collection on 100 g fat/day diet
- Abnormal if >7 g/day
- Secretin Stimulation Test (most accurate test for pancreatic exocrine insufficiency)
- Peak bicarbonate concentration abnormal if <80 mEq/L in duodenal secretions
- Serum trypsinogen
IX. Differential Diagnosis: Common
- Acute Cholecystitis
- Choledocolithiasis (Common Bile Duct Stone)
- Acute Pancreatitis
- Mesenteric Ischemia
- Peptic Ulcer Disease
- Pancreatic Carcinoma
X. Differential Diagnosis: Other Causes
XI. Imaging
- Abdominal XRay
- Pancreatic calcifications (30-60% of cases)
-
CT Abdomen (preferred first-line test)
- Pancreatic Pseudocyst
- Pancreatic duct dilatation (detects down to 7 mm duct dilitation)
- Pseudoaneurysm
- Pancreatitic necrosis
- Pancreatic parenchymal atrophy
- Pancreatic Mass
- Obtain tri-phasic pancreatic CT if Pancreatic Cancer is suspected
- Abdominal MRI and MR Cholangiopancreatography (MR/MRCP)
- Indicated for non-diagnostic CT imaging
XII. Diagnosis
- Endoscopic Ultrasound
- Preferred over ERCP due to much lower complication rate and high sensitivity
- Can be combined withg FNA biopsy to evaluate mass lesions for malignancy
-
Endoscopic Retrograde Cholangiopancreatography (ERCP)
- Irregular dilation of main pancreatic duct
- Pruning of pancreatic duct branches
- Complications include Acute Pancreatitis, gastrointestinal Hemorrhage and Ascending Cholangitis
XIII. Evaluation
- History, exam and laboratory findings consistent with Chronic Pancreatitis
- No findings of Acute Pancreatitis
- Differential Diagnosis considered
- Diagnosis
- Step 1: Start
- CT Abdomen with contrast
- Step 2: If non-diagnostic CT
- Abdominal MR/MRCP
- Step 3: If non-diagnostic MR/MRCP or if pancreatic mass identified requiring biopsy
- Endoscopic Ultrasound (and if indicated, biopsy)
- Step 4: If non-diagnostic endoscopic Ultrasound
- Obtain Pancreatic Exocrine function Tests
- Step 5: If non-diagnostic Pancreatic Exocrine function Tests
- Step 1: Start
XIV. Management: Medical
- Treat exacerbations as in Acute Pancreatitis
- Pain control
- Acetaminophen (Tylenol)
- NSAIDs
- Other-non-Opioids
- Tricyclic Antidepressants (e.g. Amitriptyline)
- SNRI (e.g. Venlafaxine, Duloxetine)
- Gabapentin or Pregabalin
- Cautious use of opiods
- High abuse potential and common outcome in chronic cases
- Denervation
- Celiac Nerve Block
- Transthoracic splanchniectomy
- Avoid exacerbating factors
- Dietary changes
- Follow Low Fat Diet
- Eat smaller meals
- Malabsorption Management (if steatorrhea)
- Pancreatic Enzyme Replacement
- Give 40,000 units of Lipase
- Proton Pump Inhibitor (or H2 Blocker)
- Consider one-time DEXA Scan (as well as Vitamin D level)
- Other Vitamin Supplementation (esp. fat soluble Vitamins, ADEK and B12)
- Pancreatic Enzyme Replacement
- Treat comorbid conditions
- Diabetes Mellitus (common)
- Typically requires Insulin
- Major Depression (common)
- Antidepressants (e.g. SSRIs)
- Diabetes Mellitus (common)
- Avoid non-indicated medications
XV. Management: Procedures
-
Extracorporeal Shock Wave Lithotripsy
- Consider in high pancreatic stone burden
- ERCP Indications
XVI. Management: Surgery
- Performed in up to 50% of longstanding Chronic Pancreatitis cases
- Surgical Indications
- Intractable pain refractory to ERCP and other measures (most common indication)
- Suspected Pancreatic Cancer
- Compression from surrounding tissue
- Biliary or pancreatic strictures
- Duodenal stenosis
- Pseudocysts refractory to endoscopic drainage
- Peritoneal or pleural fistulas
- Vascular complications (including Hemorrhage)
- Surgical procedures: Decompression for large duct disease
- Lateral pancreaticojejunostomy (most common)
- Longterm pain relief in >60% of patients
- Cystenterostomy (for pseudocyst)
- Sphincterotomy or spinchteroplasty
- Lateral pancreaticojejunostomy (most common)
- Surgical procedures: Resective for pancreatic tumor or small duct disease
- Whipple Procedure or Pancreatoduodenectomy (most common surgery for Chronic Pancreatitis)
- Pain relief in 85% of Chronic Pancreatitis cases and <3% mortality
- Total pancreatectomy
- Procedure of last resort (high complication rate, poor efficacy in pain relief)
- Performed with autologous islet cell transplant
- Whipple Procedure or Pancreatoduodenectomy (most common surgery for Chronic Pancreatitis)
XVII. Complications
- Recurrent Acute Pancreatitis
- Chronic Abdominal Pain
- Narcotic Addiction (secondary to Chronic Pain)
-
Vitamin B12 Malabsorption
- More common with Alcoholism, Cystic Fibrosis\
-
Diabetes Mellitus
- Occurs in most patients within 5 years of onset Chronic Pancreatitis
- Non-Diabetic Retinopathy
- Osteoporosis (>23% of patients)
- Weight loss (>40% of patients)
- Gastrointestinal Bleeding
- Pancreatic carcinoma (very high risk, >25% of cases)
- Consider screening hereditary Pancreatitis patients starting at age 40 years old
- Screening with endoscopic Ultrasound, CT Abdomen, or ERCP
- Subcutaneous Fat Necrosis
- Pseudocyst
- Malabsorption and steatorrhea (>10%)
- Biliary duct, duodenal or gastric obstruction
- Pancreatic fistula (Ascites, Pleural Effusion)
- Pseudoaneurysm (esp. splenic artery)
- Fat soluble Vitamin Deficiency (Vitamins A, D, E, K) - rare
XVIII. References
- Forsmark in Feldman (2006) Sleisenger & Fordtran's Gastrointestinal and Liver Disease, Chap 57
- Ahmad (2006) Curr Probl Surg 43: 127-238 [PubMed]
- Barry (2018) Am Fam Physician 97(6): 385-93 [PubMed]
- Fry (2007) Am J Surg 194: S45-S52 [PubMed]
- Nair (2007) Am Fam Physician 76: 1679-94 [PubMed]