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Hepatobiliary Disease, Portal Hypertension & Syndromes of Liver Damage

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1. Normal Hepatic Physiology

• Synthetic functions: coagulation factors (II, V, VII, IX, X, XI, XII, fibrinogen), albumin, acute-phase proteins
• Metabolic functions: gluconeogenesis, lipid metabolism, drug/toxin biotransformation, ammonia detoxification (urea cycle)
• Excretory functions: bilirubin conjugation and secretion into bile, bile salt synthesis
• Immune/clearance functions: Kupffer cell phagocytosis; removal of activated coagulation factors from circulation

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2. Etiology of Hepatobiliary Disease

Infectious

Toxic / Drug-Induced

• Acetaminophen accounts for ~50% of acute liver failure in the United States (zone 3 perivenular necrosis via N-acetyl-p-benzoquinone imine — NAPQI)
• Alcohol: steatohepatitis → cirrhosis
• Valproate, tetracycline, methotrexate (idiosyncratic or dose-related)

Metabolic / Genetic

Biliary/Vascular

• Primary biliary cholangitis (PBC), primary sclerosing cholangitis (PSC)
• Budd-Chiari syndrome (hepatic vein outflow obstruction)
• Right-sided heart failure → congestive hepatopathy

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3. Pathology of Liver Damage

Cellular Response to Injury

1. Steatosis (fat accumulation) — macro- or microvesicular
2. Ballooning degeneration (hydropic change)
3. Apoptosis → acidophil/Councilman bodies
4. Necrosis: zone-specific (zone 3 in ischemia/acetaminophen; zone 1 in yellow fever); bridging necrosis spans portal tracts to central veins; pan-acinar necrosis in massive failure

Fibrosis and Cirrhosis

• Normally stores vitamin A (lipid droplets) in the Space of Disse
• When activated by TGF-β, PDGF, TNF-α, ROS → differentiates into fibrogenic myofibroblasts → collagen deposition
• Collagen in the Space of Disse causes "capillarization" of sinusoids (defenestration), disrupting hepatocyte-plasma exchange

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4. Portal Hypertension

Definition & Normal Threshold

• HVPG ≥10 mmHg: varices begin to form
• HVPG ≥12 mmHg: variceal hemorrhage and ascites risk

Etiology — Classification by Level

• Portal vein thrombosis / structural narrowing
• Massive splenomegaly with ↑ splenic blood flow

• Cirrhosis (all causes) — dominant cause worldwide
• Nodular regenerative hyperplasia
• Primary biliary cholangitis
• Schistosomiasis (periportal fibrosis)
• Massive fatty change, sarcoidosis, amyloidosis
• Infiltrative malignancy (primary or metastatic)
• HCC with portal vein invasion

• Severe right-sided heart failure
• Constrictive pericarditis
• Budd-Chiari syndrome (hepatic vein outflow obstruction)

Pathophysiology / Mechanism

1. Increased sinusoidal resistance (fixed + functional):
   • Fixed: fibrosis, regenerative nodules compress sinusoids
   • Functional: intrahepatic vasoconstriction due to ↓ NO production by sinusoidal endothelium + ↑ endothelin-1, angiotensinogen, eicosanoids → stellate cell/myofibroblast contraction
2. Increased portal venous inflow (hyperdynamic circulation):
   • Splanchnic arterial vasodilation (principal mediator: NO from excessive systemic production)
   • ↑ splanchnic blood flow → ↑ portal venous efflux
   • Systemic vasodilation → ↓ effective arterial blood volume → activation of RAAS + sympathetic NS → Na⁺ and water retention → plasma volume expansion → further ↑ portal inflow

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5. Four Major Consequences of Portal Hypertension

(A) Varices & Variceal Hemorrhage

• Portosystemic collaterals form when coronary/gastric veins reverse flow
• Gastroesophageal varices are clinically most important
• Rupture risk proportional to variceal diameter and intravariceal pressure
• Mortality from first bleed: ~20–30%

(B) Ascites

• Accumulation of fluid in the peritoneal cavity; cirrhosis accounts for 85% of cases
• Requires HVPG ≥12 mmHg
• Mechanism: sinusoidal hypertension + Na⁺ retention (RAAS activation)
• Advanced: refractory ascites, hyponatremia (water retention), hepatorenal syndrome

(C) Portosystemic Venous Shunts

• Esophageal varices, hemorrhoidal varices, caput medusae (periumbilical), retroperitoneal collaterals
• Bypass hepatic Kupffer cells → toxins/bacteria reach systemic circulation → encephalopathy risk

(D) Congestive Splenomegaly

• Passive congestion → splenomegaly → hypersplenism: thrombocytopenia, leukopenia, anemia

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6. Syndromes of Liver Damage / Hepatic Failure

Acute Liver Failure (Fulminant Hepatic Failure)

• Acetaminophen overdose (~50% of US cases)
• Autoimmune hepatitis, other drugs/toxins
• Viral: HAV, HBV, HEV (Asia)
• Rare: Budd-Chiari, Wilson disease, lymphoma/leukemia

1. Nausea, vomiting, jaundice → transaminases markedly elevated
2. Encephalopathy (asterixis, confusion → coma)
3. Coagulopathy (easy bruisability → intracranial bleeding)
4. Cholestasis (↑ bilirubin, bile stasis)
5. Multi-organ failure

Chronic Liver Failure / Decompensated Cirrhosis

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7. Physical Examination Signs

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8. Diagnostic Evaluation

Liver Function Tests

Serologic Markers

• HBsAg: active HBV infection
• Anti-HBs: recovery/immunity
• HBeAg: high replicative state of HBV
• Anti-HCV: exposure; confirmed by HCV RNA
• Anti-HAV IgM: acute HAV infection
• AMA (anti-mitochondrial Ab): primary biliary cholangitis
• ANA, anti-smooth muscle Ab: autoimmune hepatitis
• Ceruloplasmin ↓, urine copper ↑: Wilson disease
• Ferritin, transferrin saturation ↑: hemochromatosis

Ascites Evaluation: SAAG

• SAAG (serum-ascites albumin gradient) ≥1.1 g/dL → portal hypertension cause
• PMN count in ascitic fluid >250/μL → spontaneous bacterial peritonitis (SBP)

Hepatic Venous Pressure Gradient (HVPG)

• Gold standard to quantify portal hypertension
• HVPG >10 mmHg: clinically significant portal hypertension

MELD Score

MELD = [0.957 × ln(Cr) + 0.378 × ln(Bil) + 1.12 × ln(INR) + 0.643] × 10

Imaging

• Ultrasound: first-line; detects nodularity, ascites, splenomegaly, portal vein dilation, Doppler flow reversal
• CT/MRI: staging, detection of HCC, vascular anatomy
• Elastography (FibroScan): non-invasive fibrosis quantification
• Liver biopsy: gold standard for fibrosis staging, hepatitis grading, storage disease diagnosis

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9. Complications and Related Syndromes

Spontaneous Bacterial Peritonitis (SBP)

• Infection of ascitic fluid without secondary cause
• Mechanism: bacterial translocation from gut lumen → mesenteric lymph nodes → transient bacteremia → colonizes ascitic fluid (low complement, low opsonic activity)
• Organisms: gram-negative enteric (E. coli, Klebsiella) predominantly; increasing multidrug-resistant organisms with prophylaxis use
• Diagnosis: PMN >250/μL in ascitic fluid
• Treatment: 3rd-generation cephalosporins (cefotaxime); albumin IV to prevent hepatorenal syndrome
• Prophylaxis: norfloxacin or trimethoprim-sulfamethoxazole in high-risk patients (prior SBP, low protein ascites)

Hepatorenal Syndrome (HRS)

• Prerenal kidney injury in cirrhosis from maximal splanchnic vasodilation → renal vasoconstriction
• HRS-AKI (Type 1): rapidly progressive, creatinine doubles within 2 weeks; triggered by SBP, hemorrhage
• HRS-non-AKI (Type 2): slower, associated with refractory ascites
• Treatment: vasoconstrictor (terlipressin or norepinephrine) + albumin; liver transplantation is definitive

Hepatic Encephalopathy (HE)

• Neuropsychiatric manifestation caused by ammonia (from gut bacteria + enterocytes) bypassing hepatic detoxification
• Ammonia → astrocyte swelling (glutamine as osmolyte) → cerebral edema
• Grades:
  • Grade 1: sleep-wake inversion, forgetfulness
  • Grade 2: confusion, bizarre behavior, disorientation
  • Grade 3: lethargy, profound disorientation
  • Grade 4: coma
• Hallmark sign: asterixis (flapping tremor)
• Treatment: lactulose (reduces ammonia production/absorption), rifaximin (non-absorbable antibiotic), dietary protein restriction (avoid excess)
• Precipitants: GI bleed, infection, constipation, hypokalemia, sedatives

Hepatopulmonary Syndrome

• Intrapulmonary vascular dilatations → V/Q mismatch and shunting → hypoxemia
• Diagnosis: PaO₂ <80 mmHg + positive contrast echocardiography (microbubbles in left heart)
• Signs: platypnea (dyspnea worsening upright), orthodeoxia, clubbing, cyanosis
• Present in 5–10% of liver transplant candidates; resolves post-transplant

Portopulmonary Hypertension

• Pulmonary arterial hypertension in the setting of portal hypertension
• Diagnosis: mean PAP >25 mmHg on right heart catheterization + PCWP <15 mmHg

Coagulopathy of Liver Disease

• Liver synthesizes factors II, V, VII, IX, X, XI, XII, fibrinogen + anticoagulants (protein C, S, antithrombin)
• Paradoxically "rebalanced" coagulopathy — bleeding AND thrombosis risk
• PT/INR prolonged; thrombocytopenia from hypersplenism

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10. Treatment Overview

Treating the Underlying Cause

Reducing Portal Pressure

• Non-selective beta-blockers (propranolol, carvedilol): reduce cardiac output AND splanchnic vasodilation; primary and secondary prophylaxis against variceal hemorrhage and decompensation
• Endoscopic band ligation (EBL): acute variceal bleeding and secondary prophylaxis
• Endoscopic sclerotherapy: alternative to EBL
• TIPS (Transjugular Intrahepatic Portosystemic Shunt): refractory bleeding, refractory ascites; creates intrahepatic porto-systemic shunt; risk: worsening encephalopathy

Managing Ascites

• Na⁺ restriction (<2 g/day), fluid restriction (if hyponatremic)
• Spironolactone (first-line diuretic; blocks aldosterone) ± furosemide
• Large-volume paracentesis + albumin replacement (8 g per liter removed) for tense ascites
• TIPS for refractory ascites

Hepatic Encephalopathy

• Identify and treat precipitants
• Lactulose: cathartic; acidifies colon → traps NH₃ as NH₄⁺; target 2–3 soft stools/day
• Rifaximin: poorly absorbed antibiotic; reduces gut ammonia-producing bacteria; maintenance therapy

Liver Transplantation

• Definitive therapy for end-stage liver disease
• Indicated when MELD-Na ≥15 or decompensating events occur
• Corrects both liver failure and portal hypertension
• HCC within Milan criteria is a transplant indication
• Post-transplant: lifelong immunosuppression (calcineurin inhibitors ± mycophenolate)

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Summary Table: Syndromes of Liver Damage

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Diagnosis & Physical Examination of Hepatobiliary Disease

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1. Diagnostic Approach — Overview

1. Careful history
2. Physical examination
3. Screening laboratory studies: total and direct bilirubin, ALT, AST, ALP, PT

"Regardless of how the patient comes to medical attention, the diagnostic approach begins with a careful history, physical examination, and screening laboratory studies... The ability to distinguish between liver disease and biliary tract obstruction is the major goal of the initial evaluation." — Goldman-Cecil Medicine, p. 1558

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2. History Taking — Key Elements

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3. Physical Examination

Systematic Approach

Inspection (General)

Hands & Arms

Face & Neck

Chest & Abdomen

Lower Limbs

Summary Table: Physical Exam Signs by Disease Type

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4. Diagnostic Algorithm — Liver Test Abnormalities

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5. Laboratory Investigations

Serum Enzyme Tests (Markers of Injury)

• ≤3× ULN: parenchymal disease (hepatitis, cirrhosis)
• 3–10× ULN: biliary obstruction, cholestatic disease

• 10× ULN: complete biliary obstruction, infiltrative disease (lymphoma, granulomas)

Markers of Hepatic Synthetic Function

Bilirubin Fractions

Special Serologic Tests

Ammonia

• Elevated in portosystemic shunting or severe hepatic dysfunction
• Does not correlate well with encephalopathy grade clinically
• Levels >150 μmol/L useful as supportive evidence only
• Best measured on iced arterial sample — Goldman-Cecil Medicine, p. 1560

Hematologic Findings in Liver Disease

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6. Imaging

Obstructive Jaundice vs. Parenchymal Disease — Imaging Selection

Liver Biopsy

• Gold standard for: fibrosis staging, hepatitis grading, storage disease diagnosis, infiltrative malignancy
• Indications: persistently elevated aminotransferases without diagnosis after non-invasive workup; suspected autoimmune hepatitis; metabolic liver disease characterization
• Percutaneous, transjugular (if coagulopathy), or laparoscopic

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7. Distinguishing Obstructive vs. Parenchymal Jaundice

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8. Complications of Hepatobiliary Disease

A. Complications of Cirrhosis

"Decompensated cirrhosis is defined by the development of ascites, variceal hemorrhage, encephalopathy, or jaundice." — Goldman-Cecil Medicine, p. 1615

1. Portal Hypertension → Varices → Variceal Hemorrhage

• Most lethal acute complication
• Gastroesophageal varices develop when HVPG ≥10 mmHg; rupture when HVPG ≥12 mmHg
• Presentation: hematemesis, melena, hematochezia + hemodynamic compromise
• Mortality 15–20% per episode
• Management: IV octreotide (splanchnic vasoconstriction), endoscopic band ligation, beta-blockers (prophylaxis), TIPS (refractory)

2. Ascites

• HVPG ≥12 mmHg threshold required
• Mechanism: sinusoidal HTN → splanchnic vasodilation → RAAS activation → Na⁺ retention
• Graded: Grade 1 (detectable only on ultrasound) → Grade 2 (moderate, obvious) → Grade 3 (tense/refractory)
• Complications of ascites:
  • Spontaneous bacterial peritonitis (SBP)
  • Hepatorenal syndrome (HRS)
  • Hyponatremia (water retention, dilutional)
  • Umbilical hernia (from ↑ intra-abdominal pressure)

3. Spontaneous Bacterial Peritonitis (SBP)

• Infection of ascitic fluid without secondary cause
• Most common organisms: E. coli, Klebsiella, streptococci
• Diagnosis: ascitic fluid PMN ≥250 cells/μL (even without positive culture)
• Bacteria cultured in only 40–50% of cases
• Clinical features: fever, jaundice, abdominal pain/tenderness ± rebound; up to 1/3 are initially asymptomatic and present with encephalopathy or renal failure
• Treatment: IV cefotaxime (3rd-generation cephalosporin) + IV albumin 1.5 g/kg day 1, 1 g/kg day 3 (prevents HRS)
• Prophylaxis: norfloxacin or trimethoprim-sulfamethoxazole for secondary prevention

4. Hepatorenal Syndrome (HRS)

• Functional (not structural) renal failure in cirrhosis; diagnosis of exclusion
• Caused by maximal splanchnic vasodilation → reflex renal vasoconstriction → ↓ GFR
• HRS-AKI (Type 1): creatinine doubles to >2.5 mg/dL within 2 weeks; poor prognosis; often precipitated by SBP or hemorrhage
• HRS-non-AKI (Type 2): slower onset; associated with refractory ascites; less acute
• Urine: low Na⁺ (<10 mEq/L), no proteinuria, no casts (distinguishes from ATN)
• Treatment: vasoconstrictors (terlipressin, norepinephrine) + IV albumin; liver transplant is definitive

5. Hepatic Encephalopathy (HE)

• Neuropsychiatric syndrome from ammonia + astrocyte swelling
• Incidence 2–3% per year in cirrhosis
• Clinical grades:
  • Grade 1: sleep-wake inversion, irritability, mild confusion
  • Grade 2: lethargy, disorientation, inappropriate behavior
  • Grade 3: marked confusion, stupor, semi-responsiveness
  • Grade 4: coma
• Hallmark: asterixis (flapping tremor); fetor hepaticus
• EEG: generalized slow waves + triphasic waves
• Ammonia levels unreliable for grading; levels >150 μmol/L supportive of HE
• Minimal HE (subclinical): present in up to 80% of cirrhotics; detected by psychometric tests only
• Precipitating factors: GI bleed, infection, constipation, hypokalemia, alkalosis, sedatives, excess dietary protein, dehydration
• Treatment: lactulose (target 2–3 soft stools/day), rifaximin (maintenance), identify + correct precipitant

6. Hepatocellular Carcinoma (HCC)

• Complication of cirrhosis (especially HBV, HCV, alcoholic, NASH, hemochromatosis)
• Risk: ~1–4% per year in cirrhotic patients
• Surveillance: ultrasound ± AFP every 6 months
• Diagnosis confirmed by dynamic CT/MRI (arterial enhancement + portal washout = hallmark)
• Regan isozyme (ALP variant) associated with HCC
• Treatment depends on stage: resection, ablation, TACE, sorafenib/lenvatinib, transplant (Milan criteria)

7. Hepatopulmonary Syndrome (HPS)

• Intrapulmonary vascular dilation → V/Q mismatch + right-to-left shunting
• Symptoms: exertional dyspnea → progressive hypoxemia, orthodeoxia (dyspnea worsening upright), platypnea (breathlessness upright)
• Signs: clubbing, cyanosis, vascular spiders
• Present in 5–10% of patients awaiting liver transplant
• Diagnosis: PaO₂ <80 mmHg + contrast echocardiography showing delayed microbubble appearance in left heart (after 3–5 beats)
• Alternative: ⁹⁹ᵐTc-MAA lung scan showing >6% abnormal shunting to brain
• Treatment: liver transplantation (only definitive therapy; reverses HPS)

8. Portopulmonary Hypertension (PPH)

• Pulmonary arterial hypertension in the setting of portal hypertension
• Diagnosis: mean PAP >25 mmHg + PCWP <15 mmHg on right heart catheterization
• Manifestations: progressive dyspnea, right heart failure
• Severe PPH (mPAP >50 mmHg) is a contraindication to liver transplantation (prohibitive surgical mortality)
• Treatment: pulmonary vasodilators (epoprostenol, sildenafil, bosentan)

9. Coagulopathy

• Liver produces ALL coagulation factors except von Willebrand factor
• Factors II, V, VII, IX, X, XI, XII + fibrinogen deficient in liver failure
• Factor VII is first and most severely depressed (shortest half-life)
• Paradox: rebalanced coagulopathy — simultaneous loss of pro- and anticoagulants (protein C, protein S, antithrombin) → both bleeding AND thrombosis risk
• DIC can develop as secondary complication in acute liver failure

10. Hypersplenism

• Passive congestion → splenomegaly → sequestration and destruction of blood cells
• Results: thrombocytopenia (<100,000/μL), leukopenia, anemia
• Thrombocytopenia is often the first lab abnormality in compensated cirrhosis; surrogate marker of portal hypertension

B. Complications of Specific Hepatobiliary Diseases

Acute Cholecystitis

• Complication of gallstone disease (95%): stone impaction in cystic duct → gallbladder inflammation
• Signs: Murphy's sign (positive in ~65%), RUQ tenderness, fever, leukocytosis
• Complications: gangrenous cholecystitis, empyema, perforation (peritonitis), cholecystoenteric fistula, gallstone ileus

Ascending Cholangitis

• Biliary obstruction + infection → Charcot's triad: RUQ pain + fever/rigors + jaundice
• Reynolds' pentad (severe): Charcot's triad + shock + altered mental status → biliary sepsis
• Most common organisms: gram-negatives (E. coli, Klebsiella) ± anaerobes
• Urgently needs biliary drainage (ERCP ± sphincterotomy / PTC)

Choledocholithiasis

• Common bile duct stones: jaundice, cholangitis, acute pancreatitis
• Diagnosis: MRCP (non-invasive), EUS, or ERCP (diagnostic + therapeutic)

Budd-Chiari Syndrome

• Hepatic vein / IVC outflow obstruction → postsinusoidal portal hypertension
• Acute: painful hepatomegaly, ascites, liver failure
• Causes: hypercoagulable states (myeloproliferative disorders, Factor V Leiden, OCP use), tumor invasion
• Diagnosis: Doppler ultrasound (absent/reversed hepatic vein flow), CT/MRI
• Treatment: anticoagulation, TIPS, liver transplantation

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9. MELD Score — Severity & Transplant Prioritization

• MELD-Na adds serum sodium adjustment for MELD ≥12
• Predicts 90-day mortality in end-stage liver disease
• Score ≥15: benefits of transplantation outweigh risks
• Score ≥40: >70% 3-month mortality without transplant

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10. Summary: Complications at a Glance

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