Chronic Calcific Pancreatitis (CCP)

1. ANATOMY OF THE PANCREAS (Normal)

• Exocrine pancreas (90% of mass): Acinar cells secrete digestive enzymes (as zymogens) into an elaborate ductal system. The main pancreatic duct (Wirsung duct) runs the length of the gland, normally ≤3 mm in the body and ≤2.5 mm overall, joining the common bile duct at the ampulla of Vater to drain into the duodenum.
• Endocrine pancreas (islets of Langerhans, ~2%): Scattered clusters of beta (insulin), alpha (glucagon), delta (somatostatin), and PP cells, concentrated more in the tail.
• Ductal cells: Secrete bicarbonate-rich fluid (1-2 L/day) to neutralize duodenal acid and carry zymogens downstream.

• The intrapancreatic portion of the common bile duct traverses the pancreatic head - vulnerable to compression in fibrotic CP
• The main pancreatic duct system can become chain-of-lakes in CCP due to alternating strictures and dilations

2. PHYSIOLOGY (Normal Pancreatic Function)

3. PATHOPHYSIOLOGY

Core Pathophysiologic Mechanisms

• Fibrosis + ductal obstruction → acinar cell loss → exocrine insufficiency
• Initially islets are spared (relative sparing), but eventually the sclerotic tissue envelops and destroys them → endocrine insufficiency (diabetes)

4. RISK FACTORS (TIGAR-O Classification)

• Endemic within 30 degrees of the equator - Indian subcontinent (particularly southern India, prevalence ~1 in 500-800), sub-Saharan Africa, Brazil
• Traditionally linked to protein-calorie malnutrition + cassava (tapioca) consumption - cassava contains cyanogenic glycosides that generate free radical toxins
• SPINK1 mutation found in ~40-50% of tropical pancreatitis patients
• Disease of youth: mean age of onset ~24 years; >90% present before age 40
• Male predominance - Sleisenger & Fordtran's, p. 4136-4141

5. CLINICAL MANIFESTATIONS

A. Pain (Primary Symptom)

• Recurrent, episodic epigastric pain radiating to the back; initially triggered by oral intake
• Pain intensity and frequency increase as disease progresses
• Significantly impairs quality of life; may require narcotic analgesics
• Pain paradoxically may "burn out" in end-stage disease as the gland is fully destroyed

B. Exocrine Insufficiency

• Requires >90% gland destruction before clinical manifestations appear
• Steatorrhea (oily, foul-smelling, floating stools) - most characteristic
• Chronic diarrhea, bloating, weight loss, malnutrition
• Fat-soluble vitamin deficiency (A, D, E, K) → bleeding tendency, osteopenia/osteoporosis
• Occurs in 80-90% of patients with long-standing CCP

C. Endocrine Insufficiency - Fibrocalculous Pancreatic Diabetes (FCPD)

• Diabetes mellitus occurs in >50% of tropical CCP patients (up to 40-80% in long-standing CP)
• Develops years after pain onset
• Type 3c (pancreatogenic) diabetes - insulin deficiency due to islet destruction
• FCPD is recognized as a distinct type of diabetes in India

D. Jaundice / Biliary Obstruction

• Occurs in 5-10% of patients
• Caused by fibrosis of the intrapancreatic portion of the common bile duct
• May present with cholangitis

E. Other Manifestations

• Duodenal obstruction (extensive head fibrosis): severe nausea, vomiting
• Upper GI bleeding from portal/splenic vein thrombosis (rare)
• Pseudocyst formation
• Pancreatic ascites or pleural effusion (duct disruption)
• Pancreatic cancer risk: 16-fold increased risk in long-standing CP - Sabiston Textbook of Surgery, p. 2008; Sleisenger & Fordtran's, p. 4136-4138

6. DIAGNOSTIC EVALUATION

Imaging

• Pancreatic calcifications - readily visible, highly suggestive of CCP
• Inexpensive first screen

• Dilated main pancreatic duct (>2.5 mm), intraductal stones, heterogeneous echogenicity
• Limited by body habitus and overlying bowel gas

• Most common findings: dilated MPD (68%), parenchymal atrophy (54%), pancreatic calcifications (50%)
• Sensitivity 56-95%, specificity 85-100%
• Excellent for assessing complications (pseudocysts, vascular changes, biliary dilation)
• Diagnosis with high specificity when ≥3 of: parenchymal calcifications, intraductal calcification, parenchymal atrophy, cystic lesions

CT showing pancreatic duct dilation (long arrow) and intrapancreatic calcifications (short arrow) - Sabiston Textbook of Surgery

• Lower sensitivity for calcifications than CT, but excellent for parenchymal changes
• Secretin-stimulated MRCP: evaluates ductal strictures and disruption
• Avoids radiation; preferred when CT is contraindicated

• Historically the "gold standard" for ductal imaging
• Classic finding: chain of lakes appearance (alternating dilations and strictures)
• Also shows intraductal filling defects (protein plugs/stones), CBD narrowing
• Now reserved primarily as a therapeutic tool; MRCP preferred for diagnosis
• Contraindicated if malignancy not ruled out

• Most sensitive for early/minimal-change CP
• Uses Rosemont Criteria (2009) for diagnosis:
  • Major A: Hyperechoic foci with posterior shadowing, main pancreatic duct calculi
  • Major B: Honeycombing lobularity
  • Minor: Hyperechoic nonshadowing foci, lobularity, irregular MPD contour, dilated side branches, MPD dilation, hyperechoic MPD margin
• Consistent with CP: 1 Major A + ≥3 minor, OR 2 Major A criteria

Functional Tests

Laboratory Tests

• CA 19-9 (to screen for pancreatic cancer if concern exists)
• IgG4 (if autoimmune pancreatitis suspected)
• Genetic testing: SPINK1, CFTR, PRSS1 mutations (especially in young patients, tropical pancreatitis, family history)
• Nutritional markers: albumin, pre-albumin, fat-soluble vitamins (A, D, E, K), B12

7. MANAGEMENT

A. General Measures

• Alcohol and smoking cessation - mandatory (both are independent disease accelerators)
• Low-fat diet (30-40 g/day in exocrine insufficiency)
• Correction of nutritional deficiencies: fat-soluble vitamins, B12, zinc
• Treat underlying cause (e.g., hypertriglyceridemia, hypercalcemia)

B. Pain Management (Stepwise)

1. NSAIDs - first-line analgesic
2. Tramadol - for moderate-severe pain not responding to NSAIDs
3. Strong opioids (long-acting) - reserved for severe, refractory pain; monitor for dependence
4. Adjuvant agents: Tricyclic antidepressants (TCAs), SSRIs, SNRIs, gabapentin, pregabalin for neuropathic component
5. Pancreatic enzyme supplementation: May reduce pain by negative feedback suppression of CCK (controversial)
6. Antioxidants: May benefit in tropical pancreatitis (vitamin C, E, selenium, methionine)
7. Celiac plexus block: Temporary relief; not sustained in chronic pancreatitis

C. Treatment of Exocrine Insufficiency (Pancreatic Enzyme Replacement Therapy - PERT)

• Dose: ≥40,000-50,000 IU lipase per main meal; 25,000 IU per snack
• Take with food (ideally mid-meal)
• Use enteric-coated microsphere preparations
• Add proton pump inhibitor if inadequate response (to prevent acid inactivation)
• Monitor nutritional status and fat-soluble vitamin levels

D. Treatment of FCPD (Fibrocalculous Pancreatic Diabetes)

• Insulin is usually required (most patients are insulin-deficient)
• Oral hypoglycemics have limited role
• High risk of hypoglycemia (glucagon also deficient)

E. Endoscopic Management

F. Surgical Management

• Modified Puestow procedure (lateral pancreaticojejunostomy / Roux-en-Y): Side-to-side anastomosis of unroofed pancreatic duct to jejunum; pain relief in 80%; 30% recurrence at 3-5 years
• Frey procedure (local pancreatic head resection + LPJ): For enlarged head (≥5 cm); combines decompression + resection; lower recurrence

• Whipple procedure (pancreaticoduodenectomy): When disease is predominantly in the head or malignancy cannot be excluded
• Distal pancreatectomy: For disease predominantly in body/tail
• Total pancreatectomy + islet autotransplantation (TPIAT): Last resort; preserves some islet function

• Sabiston Textbook of Surgery, p. 2008-2010; Sleisenger & Fordtran's, p. 4139-4141

Summary Table