Choledocholithiasis

Classification

• Sabiston Textbook of Surgery, p. 1832

Clinical Presentation

• Biliary colic - right upper quadrant (RUQ) or epigastric pain
• Obstructive jaundice - scleral icterus, dark urine, pale/acholic stools; onset is typically painful (distinguishing it from malignant obstruction, which is painless)
• Ascending cholangitis (Charcot's triad: fever, jaundice, RUQ pain) - due to ascending bacterial infection from the duodenum; bacteremia is present in ~74% of cases
• Gallstone pancreatitis - if the stone obstructs the pancreatic duct at the ampulla of Vater

• Symptom to Diagnosis: An Evidence Based Guide, p. 50

Diagnosis

Laboratory Findings

• Elevated total bilirubin - low sensitivity, high specificity for choledocholithiasis; >4 mg/dL is a very strong predictor
• Elevated AST, ALT, ALP - early in the disease, transaminases rise first; later, an obstructive pattern (elevated ALP, bilirubin) dominates
• Leukocytosis - raises concern for cholangitis
• Lipase >3x upper limit of normal - diagnostic for concomitant pancreatitis
• When elevated bilirubin is combined with an abnormal ultrasound, pre-test probability for choledocholithiasis approaches 90%; a patient with normal LFTs and normal ultrasound has <5% probability

Imaging

• Sabiston Textbook of Surgery, p. 1832

ASGE Risk Stratification (Predictors of Choledocholithiasis)

• Any very strong predictor = high likelihood
• Both strong predictors present = high likelihood
• No predictors = low likelihood
• All other patients = intermediate likelihood
• Mulholland and Greenfield's Surgery, p. 3073-3074

Intraoperative Cholangiogram

Management

1. Endoscopic Approach (First-line in most cases)

• ERCP with endoscopic sphincterotomy and stone extraction - the primary therapy; success rate ~84-89% for complete duct clearance in a single session
• Recommended in high-risk patients and for acutely ill patients with cholangitis requiring biliary decompression
• Recommended for stones identified before cholecystectomy: clear duct endoscopically, then proceed with laparoscopic cholecystectomy

2. Surgical Approach

• Laparoscopic bile duct exploration (transcystic or transcholedochal approach) - stone clearance rates average 95%, operative mortality ~0.5%
• Preferred when choledocholithiasis is discovered intraoperatively and surgeon expertise allows it
• Open bile duct exploration - reserved for large impacted stones, multiple failed endoscopic attempts, or anatomy precluding endoscopy (e.g., prior Roux-en-Y gastric bypass)

3. Percutaneous Approach

• Used when endoscopic and surgical options are not feasible

Summary of Timing Decisions

• Sleisenger and Fordtran's Gastrointestinal and Liver Disease, p. 1267
• Mulholland and Greenfield's Surgery, p. 3074-3075

Biliary Strictures

1. Causes and Risk Factors

A. Benign Biliary Strictures

i. Iatrogenic / Postoperative (Most Common)

• Cholecystectomy - responsible for >90% of postoperative biliary strictures in the US; laparoscopic cholecystectomy carries a 2-3x higher rate of major bile duct injury (0.4-1.3%) compared to the open technique (0.2-0.3%)
• Choledochotomy (bile duct exploration)
• Gastrectomy
• Hepatic resection
• Liver transplantation - hepatic artery thrombosis post-transplant is a recognised cause of ischemic biliary stricture

• Maingot's Abdominal Operations, p. 1057-1058

ii. Inflammatory / Chronic

• Choledocholithiasis (CBD stones) - recurrent stone impaction and cholangitis produce fibrosis and stricture formation
• Chronic pancreatitis - fibrosis of the pancreatic head compresses the intrapancreatic portion of the CBD
• Cholangitis (acute/recurrent) - ascending bacterial infection causes ductal wall inflammation and subsequent scarring
• Primary Sclerosing Cholangitis (PSC) - autoimmune disease, more common in males, strongly associated with inflammatory bowel disease (especially ulcerative colitis); causes multifocal fibro-inflammatory stricturing of intra- and extrahepatic bile ducts
• IgG4-related cholangitis - immune-mediated segmental or diffuse narrowing; responds to corticosteroids
• Parasitic infections - liver flukes (Clonorchis sinensis, Opisthorchis viverrini), Ascariasis; mechanical obstruction plus chronic ductal inflammation leads to fibrosis
• AIDS cholangiopathy - opportunistic infections (CMV, Cryptosporidium) in immunocompromised patients

iii. Congenital

• Biliary atresia - fibro-inflammatory obliteration of the bile ducts in neonates

iv. Radiation-induced

• Radiotherapy to the upper abdomen can cause late-onset ductal fibrosis and stricture

v. Traumatic

• Blunt abdominal trauma; penetrating injury to extrahepatic bile ducts

vi. Mirizzi's Syndrome

• External compression of the common hepatic duct by a large stone impacted in the cystic duct or gallbladder neck, causing a functional biliary stricture

B. Malignant Biliary Strictures

• Cholangiocarcinoma - most common primary malignancy causing biliary stricture; patients with PSC have significantly elevated risk
• Pancreatic carcinoma - compresses the intrapancreatic CBD; typically presents as painless progressive jaundice
• Gallbladder carcinoma - causes obstruction by direct invasion or secondary stricture
• Ampullary carcinoma - obstruction at the ampulla of Vater
• Metastatic lymphadenopathy - periportal nodes compressing the hilum
• Frameworks for Internal Medicine, p. 9376-9381; Bailey and Love's Short Practice of Surgery, p. 1275

2. Pathophysiology - Effect on Bile Flow and Liver Function

A. Mechanical Obstruction of Bile Flow

1. Increased luminal pressure proximal to the stricture - bile continues to be secreted by hepatocytes but cannot drain freely
2. Proximal ductal dilation - the bile ducts upstream of the stricture dilate as back-pressure builds
3. Biliary stasis - stagnant bile predisposes to stone formation, infection, and colonization by enteric bacteria (ascending cholangitis)
4. Cholestasis - impaired bile flow leads to accumulation of bile constituents (bilirubin, bile acids, cholesterol) in the hepatic parenchyma and bloodstream

"Cholestasis occurs with impaired bile flow, leading to accumulation of bile pigment in the hepatic parenchyma. Large bile duct obstruction is most commonly associated with gallstones and carcinomas; ascending cholangitis may develop. Chronic obstruction can lead to secondary sclerosing cholangitis and cirrhosis."

• Robbins, Cotran & Kumar Pathologic Basis of Disease

B. Effects on Liver Function

"Inflammation of the biliary tree results in fibrosis and stricture formation. Due to stricture formation, biliary stasis occurs, which predisposes patients to infection and hepatic abscess formation. Long-term complications include cirrhosis and liver failure."

• Yamada's Textbook of Gastroenterology

"Bile duct strictures that go unrecognized or are improperly managed can lead to severe complications such as recurrent cholangitis, secondary biliary cirrhosis, and portal hypertension."

• Schwartz's Principles of Surgery, p. 1446

C. Inflammatory Pathways (PSC)

3. Classification of Biliary Strictures (Bismuth Classification)

4. Clinical Manifestations

A. Early / Acute Presentation (Bile Duct Injury / Leak)

• Abdominal pain and distension - typically within the first week post-operatively
• Nausea and vomiting
• Fever and signs of sepsis - tachycardia, hypotension in severe cases
• Bilious drainage from incision sites or operative drains
• Biloma - loculated bile collection, presenting as a low-grade fever and localized pain
• Chemical peritonitis or frank biliary peritonitis if bile drains freely into the peritoneum
• Biliary ascites in severe leaks

B. Subacute and Chronic Presentation (Established Stricture)

"Bile duct strictures most commonly result in recurrent episodes of cholangitis but may present with isolated jaundice without infection. Liver function tests usually show evidence of cholestasis with elevations of bilirubin and alkaline phosphatase."

• Schwartz's Principles of Surgery, p. 1446

"Patients with a slowly evolving stricture may have nonspecific abdominal complaints, jaundice, pruritus, cholangitis, or derangements in liver function tests... patients can present with painless jaundice, which can be confused with a malignant stricture."

• Maingot's Abdominal Operations, p. 1061

ERCP Imaging of Biliary Strictures

PSC: Stricturing and Beading Pattern on ERCP

5. Laboratory Findings Summary