Chronic Pancreatitis

Etiology

Alcohol – stimulates exocrine secretion, causes spasm of Ampulla of Vater
Hyperparathyroidism – causes hypercalcemia, stimulates exocrine secretion
- Predisposes to precipitation of protein aggregates within the main pancreatic ductal system
Congenital anomalies of pancreatic duct – pancreatic divisium
Pancreatic trauma
Developing countries – tropical pancreatitis due to nutritional deficiencies

Pathogenesis

Hypersectretion and stimulation of exocrine pancreas and plugging of pancreatic duct with protein precipitates
- Leads to hypertension in ductal systems
First attack occurs at the head of pancreas; second attack occurs at the body and tail (where the beta cells are)
- Hence, type 1 diabetes occurs after recurrent attacks of abdominal pain

Clinical features

Patient has a history of alcohol abuse
Epigastric pain – radiates to the back
- Type A pain – recurrent episodes of pain that resolve between attacks
- Type B pain – prolonged, severe, unrelenting pain
Clinical tetrad – Abdominal pain, anorexia, type 1 diabetes mellitus, steatorrhea
Peripheral neuropathy – related to diabetes

Diagnosis

XR – pancreatic calcifications
CT – golden standard
- Shows pancreatic calcification, dilated major pancreatic duct, pseudocyst formation
Endoscopic reterograde pancreatography (ERCP) – protein precipitates, ductal dilation
Pancreatic function test – Lundh’s test
- Meal of protein, carbohydrates, fats injected into stomach
- Sample of duodenal juice taken and activity of trypsin measured
- Positive test – low trypsin activity means decreased exocrine function of the pancreas

Treatment

Non operative

3 areas to manage
- Control of abdominal pain
- Treatment of endocrine insufficiency
- Treatment of exocrine insufficiency
Abstinence of alcohol
Small volume, frequent, low fat meals
Pancreatic enzyme supplements
Octreotide (somatostatin analogue) – decreases pancreatic secretions
Exogenous insulin therapy

Operative

Endoscopic pancreatic duct stent – to decrease pressure in ductal system
Puestow’s operation (pancreaticojejunostomy) – to allow drainage of the duct
- Not recommended as intestinal bacteria can enter the pancreas
Whipple’s operation (see pic) – pancreaticoduodenectomy
- 3 anastomoses – pancreaticojejunostomy, choledojejunostomy, gastrojejunostomy

Complications

External pancreatic fistula

Drain tract left in for >7 days is a predisposing factor
Classification
- Low output fistula – <200ml/day
- High output fistula – >200ml/day
Complications – sepsis, fluid and electrolyte imbalance, skin excoriation
Diagnosis – laboratory exam of fistula shows increase amylase, trypsin, lipase
Treatment – parenteral protein; no oral intake of food; octreotide to stop exocrine secretion

Internal pancreatic fistula (pseudocyst)

Localised collection of pancreatic secretion in a cystic structure – lacks epithelial lining
- Can cause haemorrhage
Clinical features – abdominal pain; early satiety, nausea and vomiting secondary to gastroduodenal obstruction from mass effect of cyst
Diagnosis – increased amylase, CT (gold standard)
Treatment – internal drainage. Roux-en-Y

Pancreatic ascites and pleural effusion

Due to pancreatic duct disruption, leads to leakage and collection of pancreatic secretions in the peritoneum
- Alcohol abuse is the most common cause
Clinical features – painless massive ascites
Diagnosis – paracentesis shows increase amylase and albumin
Treatment – stop oral intake; nasogastric suction; paracentesis; octreotide
- Thoracocentesis for hemothorax or empyema – midclavicular line 2^nd and 5^th intercostal space

Pancreatic-enteric fistula