Ch27: Biliary Tract Diseases（胆道疾病）

Preparatory Mindset

Biliary surgery = gallstones (cholelithiasis), acute & chronic cholecystitis, choledocholithiasis, cholangitis (Charcot's triad/Reynolds' pentad), and gallbladder cancer (17CM & 18CM exam tested). The lecture (Junjie Liang, 19.2KB) covers anatomy, cholelithiasis, cholecystitis, choledocholithiasis, and malignancy. Links to Anatomy (Ch17: bile duct formation, triangle of Calot, sphincter of Oddi) and Imaging (US = first-line).

Exam mindset: the biliary tree anatomy (hepatic ducts → common hepatic → cystic → CBD → ampulla of Vater → 2nd part of duodenum), gallstone types (cholesterol vs pigment), acute cholecystitis (Murphy's sign, US findings), CBD stones (jaundice + cholangitis — Charcot's triad: RUQ pain, fever, jaundice; Reynolds' = + shock + confusion), and laparoscopic cholecystectomy (gold standard; the "critical view of safety").

Core Concepts

1. Anatomy (MUST KNOW)

• Bile drainage: right & left hepatic ducts → common hepatic duct → joins cystic duct → common bile duct (CBD) → descends behind the duodenum, through the pancreas, joins the pancreatic duct → hepatopancreatic ampulla (of Vater) → opens into the 2nd part of duodenum at the major duodenal papilla, guarded by the sphincter of Oddi
• Triangle of Calot: cystic duct, common hepatic duct, cystic artery — the dissection zone for cholecystectomy
• Gallbladder: fundus (at the tip of the 9th costal cartilage / right midclavicular line — Murphy's point), body, neck
• Blood supply: cystic artery (from the right hepatic artery); the gallbladder lies on the visceral surface of the liver (between right & quadrate lobes)
• Functions: bile storage & concentration (up to 50 ml), release with meals (CCK)

2. Gallstones (cholelithiasis) (MUST KNOW)

| Type | Composition | Risk factors | X-ray | |---|---|---|---| | Cholesterol (胆固醇性) | Cholesterol | "4F": female, forty, fertile, fat; obesity, rapid weight loss, estrogen, diabetes | Radiolucent (~10-20% calcified) | | Pigment (色素性) | Bilirubin | Hemolysis (sickle cell, spherocytosis), cirrhosis, biliary infection, ileal disease | Often radiopaque | | Mixed | — | — | — |

• Types:
• Natural history: most asymptomatic (incidental) — asymptomatic gallstones: no treatment needed (unless: large >3 cm, porcelain gallbladder, polyps, immunosuppressed, diabetic, awaiting transplant, stones in children — consider cholecystectomy)
• Complications: biliary colic (stone impacted at the cystic duct), acute cholecystitis, choledocholithiasis/CBD stones (jaundice), cholangitis, gallstone pancreatitis, gallstone ileus, gallbladder cancer (rare — chronic cholelithiasis)

3. Biliary colic (胆绞痛) (MUST KNOW)

• Cause: transient cystic duct obstruction by a stone (not true "colic" — constant pain)
• Clinical: episodic severe RUQ/epigastric pain after a fatty meal, radiates to the right shoulder/back, lasts hours, resolves spontaneously; nausea; NO fever/jaundice (afebrile, normal LFTs)
• Diagnosis: US (gallstones)
• Treatment: analgesia; elective laparoscopic cholecystectomy (to prevent complications)

4. Acute cholecystitis (急性胆囊炎) (MUST KNOW)

- US: first-line — gallstones, thickened gallbladder wall (>4 mm), pericholecystic fluid, sonographic Murphy's sign; dilated CBD if stone - Bloods: WBC ↑, CRP ↑; LFTs usually normal (if ↑/bilirubin ↑ → CBD stone/cholangitis) - CT/MRCP/HIDA if complicated/equivocal

- Admit, NPO, IV fluids, analgesia, IV antibiotics (cefazolin/piperacillin-tazobactam + metronidazole) - Early laparoscopic cholecystectomy (within 72 h/24-48 h of admission) — the standard; better than delayed (fewer complications, shorter stay) - If surgery is high-risk/not feasible: percutaneous cholecystostomy (drainage) ± interval cholecystectomy - Emergency surgery for gangrene/perforation/emphysematous

• Cause: persistent cystic duct obstruction (stone) → distension, ischemia, inflammation; 90-95% calculous; acalculous (ICU, trauma, burns, TPN — high mortality)
• Organisms: E. coli, Klebsiella, Enterococcus, anaerobes
• Clinical: RUQ pain (continuous), fever, nausea/vomiting; Murphy's sign (inspiratory arrest on deep palpation of the RUQ), palpable tender gallbladder (rarely — Courvoisier's is for malignant obstruction)
• Investigations:
• Complications: empyema, gangrene (ischemia — severe pain, peritonism), perforation (free air/peritonitis — emergency), emphysematous cholecystitis (gas-forming, diabetics — surgical emergency), Mirizzi syndrome (stone in the neck compresses the CHD), choledocholithiasis, pancreatitis
• Treatment (MUST KNOW):

5. Choledocholithiasis & cholangitis (MUST KNOW)

- Infection above a CBD obstruction (stone most common) - Charcot's triad: RUQ pain + fever (with rigors) + jaundice — present in ~50-70% - Reynolds' pentad: Charcot's triad + shock + confusion (severe/cholangitis with septic shock) - Diagnosis: clinical + US (dilated ducts, stones) + LFTs (obstructive) + blood cultures - Treatment: resuscitation + IV antibiotics (broad-spectrum: piperacillin-tazobactam/ceftriaxone + metronidazole) + URGENT biliary drainage (ERCP with sphincterotomy/stenting — first line; or PTC/percutaneous drainage; or surgical CBD exploration) — source control is life-saving - Severity: Tokyo guidelines (mild/moderate/severe — severe = organ dysfunction → urgent drainage)

• CBD stones: stones in the common bile duct (from the gallbladder or primary — pigment)
• Clinical: jaundice, RUQ pain, dark urine/pale stools (obstructive picture), ↑ ALP/bilirubin; ± pancreatitis
• Diagnosis: US (dilated CBD >6-8 mm, stone); MRCP (non-invasive cholangiogram); ERCP (therapeutic + diagnostic); EUS
• Treatment: ERCP with sphincterotomy & stone extraction (± stent) before/at laparoscopic cholecystectomy; or laparoscopic CBD exploration (LCBDE) — then cholecystectomy (remove the gallbladder — the stone factory)
• Acute cholangitis (急性胆管炎) — SURGICAL EMERGENCY (MUST KNOW):

6. Gallstone pancreatitis (胆源性胰腺炎)

• Mechanism: stone passes through the ampulla → obstructs the pancreatic duct → pancreatitis
• Clinical: epigastric pain to the back, vomiting, ↑ amylase/lipase; gallstones on US; LFTs ↑ (transient)
• Treatment: supportive (fluids, analgesia, NPO) + ERCP (early, <72 h) if cholangitis/obstructive jaundice; laparoscopic cholecystectomy during the SAME admission (after resolution) to prevent recurrence

7. Gallstone ileus (胆石性肠梗阻)

• Rare: cholecystoenteric fistula (stone erodes into the duodenum) → stone obstructs the terminal ileum → small bowel obstruction in an elderly patient without previous surgery + pneumobilia (air in the biliary tree)
• Diagnosis: CT (SBO + pneumobilia + ectopic stone = Rigler's triad)
• Treatment: enterolithotomy (remove the stone through the bowel); cholecystectomy/fistula repair may be staged

8. Gallbladder cancer (胆囊癌) (MUST KNOW)

• Risk factors: chronic cholecystitis & gallstones, porcelain gallbladder (calcified wall — 20-60% risk), large stones (>3 cm), gallbladder polyps (>1 cm), chronic infection (Salmonella typhi), congenital biliary anomalies (pancreaticobiliary maljunction), Mirizzi
• Clinical: often incidental (on cholecystectomy histology); late: RUQ pain, mass, jaundice, weight loss — poor prognosis
• Diagnosis: US/CT/MRI; polyp >1 cm or porcelain gallbladder → cholecystectomy
• Treatment: simple cholecystectomy for early (T1a); extended cholecystectomy (liver wedge/segmentectomy + lymphadenectomy) for T1b-3; palliative for advanced; poor prognosis overall
• Cholangiocarcinoma (bile duct cancer): jaundice (painless), Courvoisier's sign if below the cystic duct; Klatskin tumor (at the hilum); CA19-9; treatment: surgical resection (Whipple for distal; hilar resection/transplant for proximal — selected); stenting for palliation

High-Yield Points

• Biliary tree: hepatic ducts → CHD → + cystic → CBD → ampulla of Vater → 2nd duodenum (sphincter of Oddi)
• Cholesterol stones = 4F (female, forty, fertile, fat), radiolucent; pigment = hemolysis/cirrhosis
• Asymptomatic gallstones: usually no surgery (exceptions: porcelain, >3 cm, polyps, diabetic, immunosuppressed)
• Acute cholecystitis: Murphy's sign, US (wall >4 mm, pericholecystic fluid, sonographic Murphy); early laparoscopic cholecystectomy + antibiotics
• Choledocholithiasis: jaundice + dilated CBD; ERCP/MRCP; ERCP stone extraction + cholecystectomy
• Cholangitis: Charcot's triad (pain, fever, jaundice) / Reynolds' pentad (+ shock, confusion) = EMERGENCY: antibiotics + urgent biliary drainage (ERCP)
• Gallstone pancreatitis: ERCP if cholangitis/obstruction; cholecystectomy same admission
• Gallstone ileus: elderly SBO + pneumobilia → enterolithotomy
• Gallbladder cancer: porcelain gallbladder & polyps >1 cm → cholecystectomy
• Courvoisier's law: painless jaundice + palpable gallbladder = malignancy (not stones)

Topic Summary

Biliary disease centers on gallstones: cholesterol (4F, radiolucent) vs pigment (hemolysis). Complications: biliary colic (afebrile pain after fatty meal), acute cholecystitis (Murphy's sign; US wall thickening; early laparoscopic cholecystectomy + antibiotics), choledocholithiasis (jaundice, dilated CBD; ERCP + cholecystectomy), cholangitis (Charcot's triad / Reynolds' pentad — emergency antibiotics + urgent ERCP drainage), gallstone pancreatitis (same-admission cholecystectomy), gallstone ileus (elderly SBO + pneumobilia — enterolithotomy). Gallbladder cancer: risk (porcelain gallbladder, polyps >1 cm, large stones); cholecystectomy for risk factors. Biliary anatomy (Calot's triangle, ampulla, sphincter of Oddi) and the laparoscopic "critical view of safety" are core surgical knowledge.