Preparatory Mindset
Portal hypertension = raised portal venous pressure (normal 5-10 mmHg; >10 = portal HTN; >12 = complications). The lecture (Junjie Liang, 15.4KB) covers anatomy/physiology, portal hypertension, and Budd-Chiari syndrome. This ties directly to the Anatomy chapters (portal vein formation, portosystemic anastomoses — esophageal/rectal/paraumbilical/retroperitoneal) and the clinical consequences (varices, splenomegaly, ascites).
Exam mindset: the causes (prehepatic/hepatic/posthepatic), the complications (esophageal varices & bleeding — the most dangerous; ascites; splenomegaly/hypersplenism; portosystemic encephalopathy), the management of variceal bleeding (resuscitation, terlipressin/octreotide, endoscopic banding, TIPS, balloon tamponade), and the Budd-Chiari syndrome. The portosystemic anastomoses list is a guaranteed anatomy question (see Anatomy Ch18).
Core Concepts
1. Anatomy & physiology (MUST KNOW)
1. Esophageal (left gastric ↔ azygos) — varices (most dangerous) 2. Rectal (superior ↔ middle/inferior rectal) — hemorrhoids 3. Paraumbilical (↔ epigastric/thoracoepigastric) — caput medusae 4. Retroperitoneal (mesenteric ↔ retroperitoneal/vertebral plexuses)
- Liver blood supply: 1500 ml/min — portal vein 75%, hepatic artery 25% (artery = 50% of O2); portal vein drains the GI tract & spleen
- Portal vein formation: SMV + splenic vein behind the neck of the pancreas; receives IMV, left gastric, cystic, paraumbilical veins
- Normal portal pressure: 5-10 mmHg; portal hypertension >10 mmHg; complications typically >12 mmHg
- Portosystemic anastomoses (4 sites — MUST KNOW):
2. Classification of portal hypertension (MUST KNOW)
| Site | Causes | Features |
|---|---|---|
| Prehepatic (portal vein) | Portal vein thrombosis (PVT), splenic vein thrombosis, extrinsic compression (tumor) | Preserved liver function; varices with normal liver; PVT in cirrhosis & hypercoagulable states |
| Hepatic (intrahepatic) — most common | Cirrhosis (most common overall cause), schistosomiasis (presinusoidal), alcoholic liver disease, viral hepatitis, NASH, Wilson's, hemochromatosis | Sinusoidal (cirrhosis) vs presinusoidal (schistosomiasis) |
| Posthepatic (hepatic veins/IVC) | Budd-Chiari syndrome (hepatic vein thrombosis), IVC obstruction, severe right heart failure/constrictive pericarditis | Congestive hepatomegaly, ascites out of proportion, abdominal pain |
3. Consequences (MUST KNOW)
- Variceal bleeding = leading cause of death in portal hypertension (rupture → massive hematemesis/melena → shock) - Mortality of each bleeding episode ~15-30%
- Esophageal & gastric varices — the most dangerous complication:
- Ascites: portal HTN + sodium/water retention (aldosterone) + hypoalbuminemia + lymphatic overload
- Splenomegaly & hypersplenism: pancytopenia (anemia, leukopenia, thrombocytopenia)
- Portosystemic encephalopathy (PSE): ammonia & toxins bypass the liver → confusion, asterixis (flapping tremor), coma; precipitated by bleeding, infection, constipation, high protein, sedatives
- Caput medusae (paraumbilical collaterals), hemorrhoids
- Hepatorenal syndrome, spontaneous bacterial peritonitis (SBP) (cirrhotic ascites)
4. Clinical features (MUST KNOW)
- Underlying liver disease: jaundice, spider angiomas, palmar erythema, gynecomastia, testicular atrophy, muscle wasting
- Portal HTN signs: splenomegaly, ascites, caput medusae, hemorrhoids, varices
- Bleeding: hematemesis/melena ± shock
- Encephalopathy: confusion, asterixis, fetor hepaticus
- Investigations: LFTs/coagulation (cirrhosis: ↓albumin, ↑INR, ↑bilirubin, ↑AST/ALT), CBC (hypersplenism pancytopenia), endoscopy (varices), US/CT (cirrhosis, spleen, portal vein, ascites), portal pressure measurement, liver biopsy; exclude PVT (Doppler US/CT venogram)
5. Management of variceal bleeding (MUST KNOW)
- Vasoconstrictors: terlipressin (or octreotide/somatostatin) — splanchnic vasoconstriction → ↓ portal pressure — start immediately - Antibiotics (prophylactic — ceftriaxone): reduce infection & rebleeding - PPI (protect clot, if suspected variceal vs ulcer)
- Variceal band ligation (EVL) — treatment of choice - Injection sclerotherapy (if banding not possible)
- Balloon tamponade (Sengstaken-Blakemore tube) — temporary (max 24 h), high rebleeding/aspiration risk - TIPS (transjugular intrahepatic portosystemic shunt) — creates a shunt between portal & hepatic veins — definitive for refractory bleeding/ascites; bridge to transplant - Surgery (rarely): devascularization (Sugiura), shunt surgery — mostly replaced by TIPS - Child-Pugh & MELD scoring for prognosis/transplant assessment
- Resuscitation (ABC): secure airway (hematemesis), 2 large-bore IVs, blood products (target Hb ~70-80), correct coagulopathy, ICU
- Pharmacological (early — while arranging endoscopy):
- Endoscopy (within 12 h):
- If bleeding uncontrolled:
- Secondary prevention (after the first bleed): repeated banding until varices eradicated + non-selective β-blockers (propranolol/carvedilol — reduce portal pressure) + TIPS if refractory; consider transplant
6. Ascites management
- Sodium restriction + diuretics (spironolactone ± furosemide)
- Large-volume paracentesis + albumin (avoid post-paracentesis circulatory dysfunction)
- TIPS for refractory ascites; transplant for end-stage
- SBP prophylaxis: outpatient antibiotic prophylaxis in high-risk; treat SBP (cefotaxime + albumin)
7. Budd-Chiari syndrome (布加综合征) — MUST KNOW
- Definition: hepatic venous outflow obstruction (hepatic veins/IVC) — thrombosis (polycythemia vera, JAK2 mutation, OCP, malignancy) or membranous IVC web (Asia)
- Clinical: abdominal pain, tender hepatomegaly, ascites out of proportion, lower limb edema (IVC), dilated superficial veins; acute (fulminant) vs chronic (cirrhosis-like)
- Diagnosis: Doppler US (absent/reversed hepatic vein flow), CT/MRI venography
- Treatment: anticoagulation; TIPS/transjugular recanalization, angioplasty/stent (web); surgical shunt (mesocaval) — rarely; liver transplant for fulminant/end-stage
High-Yield Points
- Portal HTN >10 mmHg; complications >12; variceal bleeding = leading cause of death
- Most common cause = cirrhosis; prehepatic = PVT; posthepatic = Budd-Chiari
- Portosystemic anastomoses: esophageal (varices — most dangerous), rectal (hemorrhoids), paraumbilical (caput medusae), retroperitoneal
- Variceal bleed: resuscitate + terlipressin/octreotide + antibiotics + PPI → urgent banding; TIPS for refractory; balloon tamponade temporary
- Encephalopathy: ammonia, asterixis; precipitated by bleeding/infection/constipation/protein
- Hypersplenism: pancytopenia
- SBP: ascites + fever/pain → paracentesis (neutrophils >250) → cefotaxime + albumin
- Secondary prophylaxis: banding + non-selective β-blockers
- Budd-Chiari: hepatic vein outflow block; tender hepatomegaly + ascites; anticoagulation/TIPS/stent/transplant
- Portal vein = SMV + splenic behind the pancreatic neck
Topic Summary
Portal hypertension (>10 mmHg) — most commonly from cirrhosis; prehepatic (portal vein thrombosis — normal liver), posthepatic (Budd-Chiari — hepatic vein/IVC obstruction). Complications: esophageal varices (bleeding = leading cause of death), ascites, splenomegaly/hypersplenism (pancytopenia), encephalopathy (ammonia/asterixis), caput medusae, hemorrhoids — via the 4 portosystemic anastomoses. Variceal bleeding: resuscitation + terlipressin/octreotide + prophylactic antibiotics + PPI → urgent endoscopic band ligation; TIPS for refractory; balloon tamponade temporary; transplant for end-stage. Ascites: salt restriction + spironolactone/furosemide, paracentesis + albumin, TIPS. Budd-Chiari: tender hepatomegaly + ascites out of proportion → Doppler US → anticoagulation, recanalization/TIPS/stent, transplant. Secondary prophylaxis: repeat banding + non-selective β-blockers.
LMCHK OSCE Practice
- Portal HTN signs examination: inspect for caput medusae, spider angiomas, palmar erythema, gynecomastia; palpate splenomegaly; percuss ascites (shifting dullness); look for jaundice.
- Variceal bleeding drill: hematemesis in a cirrhotic → ABC, blood products, terlipressin/octreotide, ceftriaxone, PPI, urgent endoscopy + banding; explain TIPS & balloon tamponade for refractory bleeding.
- Ascites assessment & paracentesis: shifting dullness/fluid thrill; diagnostic paracentesis (SBP: neutrophils >250, albumin gradient — SAAG >1.1 = portal HTN); large-volume tap + albumin.
- Encephalopathy assessment: confusion + asterixis + fetor hepaticus; precipitating factors (bleeding, infection, constipation, high protein, sedatives); management (lactulose, rifaximin, treat precipitants).
- Child-Pugh/MELD discussion: explain how they grade cirrhosis severity & prioritize transplant.
- Budd-Chiari case: RUQ pain + tender hepatomegaly + massive ascites + leg edema → Doppler US → anticoagulation, recanalization/TIPS; explain the outflow obstruction concept.
- SBP management: fever + abdominal pain in cirrhotic ascites → paracentesis → cefotaxime + albumin; secondary prophylaxis.
- Hypersplenism: explain pancytopenia from splenic sequestration and when splenectomy/embolization is considered (rare — usually treat the portal HTN).