Surgical Complications of Chronic Pancreatitis

Intrapancreatic Complications

• Pseudocysts
• Duodenal or gastric obstruction
• Thrombosis of splenic vein
• Abscess
• Perforation
• Erosion into visceral artery
• Inflammatory mass in head of pancreas
• Bile duct stenosis
• Portal vein thrombosis
• Duct strictures and/or stones
• Ductal hypertension and dilatation
• Pancreatic carcinoma

Extrapancreatic Complications

• Pancreatic duct leak with ascites or fistula
• Pseudocyst extension beyond the lesser sac into the mediastinum, retroperitoneum, lateral pericolic spaces, pelvis, or adjacent viscera

1. Pseudocysts

• Multiple in 17% of cases; may be multiloculated
• May be intrapancreatic or extend into adjacent compartments
• Communicate with the main pancreatic duct in up to 80% of cases

• Secondary infection → abscess
• Compression of adjacent structures → superior mesenteric vein or splenic vein thrombosis
• Erosion into visceral arteries → intracystic hemorrhage or pseudoaneurysm
• Perforation → peritonitis or intraperitoneal bleeding

• Asymptomatic pseudocysts can be observed (up to 50% resolve spontaneously)
• Symptomatic or enlarging pseudocysts require drainage
• Internal drainage is preferred over external drainage to avoid a pancreaticocutaneous fistula
• Surgical options: cystogastrostomy, Roux-en-Y cystojejunostomy, cystoduodenostomy
• Endoscopic options: EUS-guided transgastric puncture with stent placement
• Distal pancreatectomy for tail pseudocysts or mid-duct disruption
• Transpapillary stenting may decompress communicating pseudocysts via the main duct

2. Inflammatory Mass in the Head of Pancreas

• Severe pain (67% with vs 40% without head enlargement)
• Bile duct stenosis / cholestasis (46% vs 11%)
• Duodenal obstruction (30% vs 7%)
• Vascular involvement (15% vs 8%)
• Diabetes mellitus (18% vs 30%)

3. Bile Duct Stenosis

• Chronic pancreatitis accounts for fewer than 10% of benign biliary strictures overall
• Fibrosis and the inflammatory head mass compress the intrapancreatic portion of the common bile duct (CBD)
• Presents with obstructive jaundice, cholangitis, or progression to secondary biliary cirrhosis
• Often requires surgical biliary bypass (hepaticojejunostomy) or inclusion in a pancreatic head resection (e.g., Whipple or Beger procedure)

4. Duodenal Obstruction

• Approximately 5% of patients with chronic pancreatitis develop symptomatic duodenal stenosis (Sleisenger & Fordtran)
• Up to 1.2% develop true duodenal strictures requiring surgical intervention (Sabiston)
• Caused by fibrosis in the head of the pancreas compressing the second part of the duodenum
• Presents with pain, nausea, vomiting, and weight loss
• Must be distinguished from pancreatic malignancy
• Treatment: gastrojejunostomy or pancreaticoduodenectomy

5. Splenic and Portal Vein Thrombosis

• Splenic vein thrombosis occurs in 4-8% of cases of chronic pancreatitis
• Caused by peripancreatic inflammation extending to the splenic vein which runs along the posterior surface of the pancreas
• Leads to left-sided (sinistral) portal hypertension with gastric variceal formation
• Bleeding risk is infrequent but mortality when it occurs is >20%
• Portal vein thrombosis results from compression by a pancreatic head mass
• Treatment: when surgery is already indicated for other reasons, splenectomy should be added to prevent variceal hemorrhage from splenic vein thrombosis

6. Pancreatic Ascites and Internal Fistula (Duct Leak)

• Both are called "internal pancreatic fistulae" and are more common in chronic than acute pancreatitis
• Pancreatic ascites and pleural effusion coexist in 14% of patients; 18% have pleural effusion alone
• Presentation: progressive abdominal distension with weight loss; pain is usually absent
• Diagnosis: paracentesis or thoracentesis showing protein >25 g/L and markedly elevated amylase; serum amylase also elevated

• Initial: bowel rest, TPN, octreotide, repeated paracentesis
• Endoscopic: transpapillary stenting across the disruption
• Surgical: Roux-en-Y pancreaticojejunostomy at the site of duct rupture (internal drainage of the leak)

7. Visceral Artery Erosion / Pseudoaneurysm

• Pseudocysts may erode into adjacent visceral arteries (splenic, gastroduodenal, hepatic arteries)
• Results in intracystic hemorrhage ("hemorrhagic pseudocyst") or pseudoaneurysm
• Presents with sudden pain, hematemesis, or melena; bleeding into the pseudocyst causes a "sentinel bleed"
• Diagnosis: CT angiography or DSA
• Treatment: urgent angioembolization is the first-line approach; surgery if embolization fails

8. Pancreatic Carcinoma

• The cumulative risk of carcinoma increases throughout the patient's lifetime
• Incidence in chronic pancreatitis ranges from 1.5% to 6% - at least 10-fold greater than age-matched controls
• In patients with chronic pancreatitis and diabetes, the risk increases 12- to 33-fold
• In patients referred for surgery with advanced chronic pancreatitis, up to 10% may harbor undiagnosed carcinoma
• Diagnosis is especially difficult because the imaging features of an inflammatory mass and carcinoma overlap
• Surveillance with periodic CA 19-9 measurements and CT/EUS is recommended
• Any drainage procedure performed for presumed chronic pancreatitis must include a biopsy to exclude malignancy

Summary Table