Ch25: Hepatic Diseases（肝脏疾病）

Preparatory Mindset

Hepatic surgery = liver anatomy & blood supply, liver abscess (pyogenic & amebic), hepatic cysts, and liver tumors (hemangioma, HCC, metastases). The lecture (Junjie Liang, 17.2KB) covers anatomy/function, liver abscess, hepatic cyst, hepatic tumor, and self-study. This links to the Anatomy (Ch17: liver blood supply — portal vein 75%, hepatic artery 25%) and Imaging (HCC enhancement pattern) chapters.

Exam mindset: the dual blood supply (portal vein 75%, hepatic artery 25% — artery supplies 50% of O2); pyogenic vs amebic liver abscess; HCC (cirrhosis/HBV, AFP, imaging triad — arterial enhancement, washout; Milan criteria for transplant); and the management principles (abscess drainage, HCC resection/ablation/TACE/transplant).

Core Concepts

1. Liver anatomy & function (MUST KNOW)

• Location: right upper quadrant below the ribs; inferior border = costal margin; superior border below the diaphragm; left border = 6th rib level, right = 5th rib; largest abdominal organ (~1500 g)
• Blood flow: ~1500 ml/min; dual supply: portal vein 75% (nutrient) + hepatic artery 25% (oxygenated — provides 50% of O2)
• Blood flow path: portal/hepatic artery → sinusoids → central vein → hepatic veins → IVC
• Segments (Couinaud): 8 segments — surgical resections follow segmental anatomy; right/left lobes divided by the middle hepatic vein (Cantlie's line)
• Functions: metabolism (carbohydrate/protein/fat), synthesis (albumin, clotting factors), detoxification, bile production, storage (glycogen, vitamins), immunity (Kupffer cells)

2. Liver abscess (肝脓肿) (MUST KNOW)

- Source: biliary (ascending cholangitis — most common), portal (appendicitis/diverticulitis — pylephlebitis), arterial (sepsis), direct (trauma, adjacent infection) - Organisms: E (17CM & 18CM exam tested). coli, Klebsiella (increasing — liver abscess in diabetics), anaerobes, Streptococcus - Clinical: fever (high, swinging), RUQ pain, tender hepatomegaly, jaundice (biliary cause), sepsis; right shoulder pain; elderly/diabetic - Diagnosis: CT/US (single or multiple cystic lesions); blood cultures; aspirate for culture; LFTs (ALP ↑), WBC ↑, CRP ↑ - Treatment: IV antibiotics (empiric: 3rd-gen cephalosporin + metronidazole) + percutaneous drainage (US/CT-guided) for larger abscesses (>3-5 cm) or failed medical; surgical drainage if percutaneous fails; treat the source (biliary drainage, appendicitis) - Complications: rupture (peritonitis), sepsis, subphrenic extension, biliary fistula

- Entamoeba histolytica; from amebic colitis; usually SINGLE, right lobe - Clinical: fever, RUQ pain, history of diarrhea; "anchovy paste" pus (sterile — no bacteria on routine culture); positive amebic serology - Treatment: metronidazole (medical — antibiotics alone cure most) + US-guided aspiration if large/at risk of rupture; percutaneous drainage NOT always needed (unlike pyogenic) - Complication: rupture into the pleura/pericardium

• Pyogenic (细菌性) — most common:
• Amebic liver abscess (阿米巴):

3. Hepatic cysts (肝囊肿)

• Simple cysts: benign, asymptomatic — incidental; symptomatic/large → laparoscopic deroofing (fenestration); exclude parasites (hydatid — Echinococcus: surgical/PAIR with albendazole)
• Polycystic liver disease: ADPKD association; symptomatic → fenestration/resection/transplant (rare)
• Hydatid cyst (Echinococcus granulosus): travel history; calcified wall, daughter cysts; treatment: albendazole ± surgery/PAIR — do NOT aspirate blindly (anaphylaxis/spillage risk)

4. Liver tumors (MUST KNOW)

- Hemangioma (肝血管瘤) — most common benign liver tumor: imaging (US: hyperechoic; CT/MRI: peripheral nodular enhancement with centripetal fill-in); no treatment unless symptomatic/rupture (very rare); do NOT biopsy (bleeding) - Focal nodular hyperplasia (FNH): central scar, "spoke-wheel" artery; benign, no malignant potential - Hepatic adenoma: oral contraceptive association; risk of hemorrhage & malignant transformation → resect if >5 cm

- Risk: cirrhosis (any cause), chronic HBV (even without cirrhosis — common in Asia), HCV, alcohol, aflatoxin, hemochromatosis - Clinical: often asymptomatic (screening of cirrhotics with US + AFP) (CM exam tested); late: weight loss, RUQ pain, hepatomegaly, jaundice, ascites, variceal bleeding (portal HTN), fever; paraneoplastic (polycythemia — erythropoietin, hypoglycemia, hypercalcemia) - Tumor marker: AFP (↑ in ~70%; screening & monitoring) - Imaging (MUST KNOW): CT/MRI triphasic: arterial phase hyperenhancement with portal/venous "washout" — diagnostic of HCC without biopsy (LI-RADS); US screening - Staging/treatment (Barcelona Clinic Liver Cancer — BCLC): - Very early/early: surgical resection (preserved liver function, single tumor), liver transplantation (Milan criteria: single ≤5 cm or up to 3 ≤3 cm — best for cirrhosis), ablation (RFA/microwave — small tumors) - Intermediate: transarterial chemoembolization (TACE) - Advanced: systemic (sorafenib/lenvatinib — TKIs; atezolizumab+bevacizumab — immunotherapy) - Palliative: best supportive care - Prognosis: depends on stage & liver function; early detection (surveillance) improves outcome

- Most common liver malignancy = METASTASES (colorectal > others) - Colorectal liver metastases: resection (metastasectomy) ± perioperative chemo → potential cure (5-yr survival ~40-50% if resectable); ablation, TACE, systemic for unresectable - Others: breast, lung, neuroendocrine (symptomatic — debulk)

• Benign:
• Hepatocellular carcinoma (HCC) (肝细胞癌) — MUST KNOW:
• Metastatic liver tumors:

High-Yield Points

• Dual supply: portal 75% / hepatic artery 25% (artery = 50% of O2)
• Pyogenic abscess: biliary source most common; E. coli/Klebsiella; fever + RUQ pain; antibiotics + percutaneous drainage
• Amebic abscess: single right lobe, anchovy pus, amebic serology; metronidazole (drain only if large/rupture risk)
• Hemangioma = most common benign; peripheral nodular enhancement, centripetal fill-in; no biopsy
• HCC: cirrhosis/HBV; AFP; arterial enhancement + washout = diagnostic; treatment per BCLC (resection/transplant-Milan/ablation/TACE/systemic)
• Milan criteria: single ≤5 cm or ≤3 tumors each ≤3 cm (transplant)
• Hepatic adenoma: OCP association; resect >5 cm (bleeding/transformation)
• Liver mets = most common liver malignancy; colorectal mets resectable → potential cure
• Hydatid: Echinococcus; albendazole ± surgery/PAIR; never blind aspirate
• FNH: central scar, benign

Topic Summary

Liver: dual blood supply (portal 75% nutrient, hepatic artery 25% oxygenated). Liver abscess — pyogenic (biliary most common, E. coli/Klebsiella; fever + RUQ pain; antibiotics + percutaneous drainage) vs amebic (single right lobe, anchovy pus, metronidazole). Hepatic cysts: simple (deroofing if symptomatic), polycystic, hydatid (albendazole ± surgery — no blind aspiration). Liver tumors: hemangioma (most common benign — no treatment/biopsy), FNH (benign), hepatic adenoma (OCP, resect >5 cm); HCC (cirrhosis/HBV, AFP, arterial enhancement + washout on triphasic CT/MRI; BCLC treatment: resection, transplant within Milan criteria, ablation, TACE, systemic sorafenib/atezolizumab+bevacizumab); metastases (most common liver malignancy — colorectal mets resectable for cure).