Biliary Tract Disorders

Biliary Basics - Bile Blueprint & Pesky Pebbles

• Bile Blueprint:

  • Produced by liver; stored & concentrated in gallbladder.
  • Composition: Bile salts (fat digestion), bilirubin, cholesterol, phospholipids.
  • Function: Emulsify fats, absorb fat-soluble vitamins (A,D,E,K).
  • Enterohepatic circulation: >95% bile salts reabsorbed (terminal ileum).

• Pesky Pebbles (Cholelithiasis):

  • Cholesterol stones (~80%): Radiolucent. Risk: 📌 4Fs (Fat, Forty, Female, Fertile), OCPs, rapid weight loss.
  • Pigment stones: Radiopaque.
    • Black stones: Hemolysis, cirrhosis (Ca bilirubinate).
    • Brown stones: Infection, stasis (Ca palmitate/stearate, cholesterol).

⭐ Cholesterol gallstones are the most common type. Risk factors often remembered by the mnemonic 📌 "4Fs": Fat (obesity), Forty (age >40), Female, and Fertile (multiparous).

Gallbladder Grief - Inflamed Gallbladder Woes

• Acute Cholecystitis: Gallbladder (GB) inflammation, usually due to cystic duct stone.
  • Symptoms: RUQ pain (>4-6 hrs, radiates R shoulder), fever, N/V.
  • Signs: Murphy's sign (+ve), Boas' sign (hyperesthesia below R scapula).
• Diagnosis (Tokyo Criteria):
  • A (Local): Murphy's, RUQ mass/pain.
  • B (Systemic): Fever, ↑CRP, ↑WBC.
  • C (Imaging): USG findings.
  • Definite: One item from A + one from B + C.
• Investigations:
  • Labs: ↑WBC, ↑CRP.
  • USG (1st line): GB wall thickening (>3-4 mm), pericholecystic fluid, sonographic Murphy's.
  • HIDA scan (if USG unclear): Non-visualization of GB.
• Management:

• Complications: Gangrene, perforation, emphysematous cholecystitis (diabetics, gas in GB wall), gallstone ileus.
• Acalculous Cholecystitis: 5-10% cases, critically ill (TPN, trauma, sepsis). Ischemia. Higher mortality.

⭐ Classic: RUQ pain >6 hrs, fever, +Murphy's sign. 1st Imaging: USG (GB wall >3-4 mm, pericholecystic fluid).

Duct Dilemmas - Blocked Pipes, Fiery Infection

• Choledocholithiasis: Gallstones in Common Bile Duct (CBD).
  • Symptoms: RUQ pain, jaundice; can be asymptomatic.
  • Dx: USG (CBD >6mm), MRCP, EUS.
  • Tx: ERCP (sphincterotomy, stone extraction).
• Ascending Cholangitis: Bacterial infection of obstructed biliary tree.
  • Causes: Choledocholithiasis (most common), strictures, malignancy.
  • Pathogens: E. coli, Klebsiella.
  • Symptoms:
    • 📌 Charcot's Triad (JFR): Jaundice, Fever, RUQ Pain.
    • Reynold's Pentad: Charcot's Triad + Hypotension + Altered Mental Status (severe sepsis).
  • Labs: ↑WBC, ↑Bilirubin, ↑ALP. Blood cultures. Imaging (USG/MRCP).
  • Tx: IV Abx, urgent biliary drainage (ERCP preferred).

⭐ Charcot's triad and Reynold's pentad are classic for ascending cholangitis. ERCP is key for diagnosis and therapeutic biliary drainage, ideally within 24-48h for severe cases.

Rarer Troubles & Tumors - Scarred Ducts & Malignant Menace

• Primary Sclerosing Cholangitis (PSC)

  • Chronic inflammation, fibrosis, strictures of intra/extrahepatic bile ducts. "Beading".
  • Patho: "Onion-skin" fibrosis. ERCP/MRCP: Multiple strictures, "Beads on a string".
  • Lab: ↑ALP, p-ANCA (+ve ~70%). High risk of cholangiocarcinoma (10-20%).

  ⭐ Strong association (~70-80%) with Ulcerative Colitis (UC).

• Cholangiocarcinoma (CCA)

  • Malignancy of biliary epithelium. Types: Intrahepatic, Perihilar (Klatskin tumor), Distal.
  • Risks: PSC, liver flukes (Clonorchis, Opisthorchis), choledochal cysts, Caroli's, Thorotrast.
  • Marker: CA 19-9 (↑, non-specific). Poor prognosis.

• Gallbladder Cancer (GBC)

  • Most common biliary tract malignancy; often advanced at diagnosis.
  • Risks: Gallstones (chronic cholecystitis), porcelain gallbladder, polyps >1 cm, chronic Salmonella typhi.

High‑Yield Points - ⚡ Biggest Takeaways

• Acute cholangitis: Charcot's triad (fever, jaundice, RUQ pain); Reynolds' pentad adds shock, altered mental status.
• Gallstones: Cholesterol (most common, 4 Fs); Pigment (black: hemolysis, brown: infection).
• Acute cholecystitis: Murphy's sign positive, due to cystic duct obstruction by stone.
• PSC: Strong ulcerative colitis link; "onion-skin" fibrosis; ↑ cholangiocarcinoma risk.
• PBC: AMA positive; autoimmune intrahepatic duct destruction; common in women.
• Courvoisier's law: Palpable, non-tender gallbladder + jaundice suggests malignancy, not stones.