Chapter 31: Liver Flashcards Preview

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Flashcards in Chapter 31: Liver Deck (191):
1

Right hepatic artery variants

Off SMA (#1 hepatic artery variant, 20%) courses behind pancreas, posterolateral to the common bile duct

2

#1 hepatic artery variant

Right hepatic artery off SMA

3

Left hepatic artery variant

Off left gastric artery (about 20%) - found in gastrohepatic ligament medially

4

Separates medial and lateral segments of the left lobe; attaches liver to anterior abdominal wall; extends to umbilicus and carries remnant of umbilical vein

Falciform ligament

5

What does the falciform ligament contain?

Remnant of umbilical vein

6

Carries the obliterated umbilical vein to the undersurface of the liver; extends from the falciform ligament

Ligamentum teres

7

Line drawn from the middle of the gallbladder fossa to IVA ; separates right and left liver lobes

Portal fissure or Cantlie's line

8

Liver segments

1: caudate
2: superior left lateral
3: inferior left lateral
4: left medial (quadrate lobe)
5: inferior right anteromedial
6: inferior right posterolateral
7: superior right posterolateral
8: superior right anteromedial

9

Liver segment: 1

Caudate

10

Liver segment: 2

Superior left lateral segment

11

Liver segment: 3

Inferior left lateral segment

12

Liver segment: 4

Left medial segment (quadrate lobe)

13

Liver segment: 5

Inferior right anteromedial segment

14

Liver segment: 6

Inferior right posterolateral segment

15

Liver segment: 7

Superior right posterolateral segment

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Liver segment: 8

Superior right anteromedial segment

17

Peritoneum that covers the liver

Glisson's capsule

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Area on the posterior-superior surface of liver not covered by Glisson's capsule

Bare area

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Lateral and medial extensions of the coronary ligament on the posterior surface of the liver; made up of peritoneum

Triangular ligaments

20

Where does the portal triad enter?

Segments 4 and 5

21

Where does the gallbladder lie?

Segments 4 and 5

22

Liver macrophages

Kupffer cells

23

What composes the portal triad?

Common bile duct (lateral), portal vein (posterior), and proper hepatic artery (medial); come together in the hepatoduodenal ligament (porta hepatis)

24

Porta hepatis clamping; will not stop hepatic vein bleeding

Pringle maneuver

25

Entrance to lesser sac

Foramen of Winslow

26

Borders of Foramen of Winslow (entrance to lesser sac)

- Anterior: portal triad
- Posterior: IVC
- Inferior: duodenum
- Superior: liver

27

What forms the portal vein?

Forms from superior mesenteric vein joining splenic vein (no valves)

28

Where dose inferior mesenteric vein drain?

Enters splenic vein

29

2 in liver
- 2/3 of hepatic blood flow

Portal veins

30

Where are L / R portal vein located?

Left: goes to segment 2, 3, 4
Right: goes to segment 5, 6, 7, 8

31

Arterial blood supply of the liver

Right, left, and middle hepatic arteries (follows hepatic vein system below)

32

What is the middle hepatic artery a branch of?

MC a branch off the left hepatic artery

33

Arterial supply of most primary and secondary liver tumors

Hepatic artery

34

How many hepatic veins are there? Where do they drain?

3 hepatic veins
- Drain into IVC

35

Location left hepatic vein

2, 3 and superior 4 segments

36

Location of middle hepatic vein

5 and inferior 6 segments

37

Location of right hepatic vein

6, 7, and 8 segments

38

What does middle hepatic vein come off of?

Left hepatic vein in 80% before going to IVC; other 20% goes directly into IVC

39

Drain medial aspect of right lobe directly to IVC

Accessory right hepatic veins

40

Where do inferior phrenic veins drain?

Also drain directly into the IVC

41

Liver lobe: receives separate right and left portal and arterial blood flow; drains directly into IVC via separate hepatic veins

Caudate lobe

42

Where is alkaline phosphatase located?

Normally located in canalicular membrane

43

Where does nutrient uptake occur?

Sinusoidal membrane

44

Usual energy source for liver; glucose is converted to glycogen and stored.
- Excess glucose converted to fat

Ketones

45

Where is urea synthesized?

Liver

46

Coagulation factors not made in the liver

von Willebrand factor and factor 8 (endothelium)

47

Type of vitamins stored in the liver

Liver stores large amount of fat-soluble vitamins

48

The only water-soluble vitamin stored in the liver

b12

49

Most common problems with hepatic resection

Bleeding and bile leak

50

Hepatocytes most sensitive to ischemia

Central lobular (acinar zone 3)

51

How much of the liver can be safely resected?

75%

52

Breakdown product of hemoglobin (Hgb -> heme -> biliverdin -> bilirubin)

Bilirubin

53

What improves water solubility of bilirubin?

Conjugated to glucuronic acid (glucuronyl transferase) in the liver

54

Where is conjugated bilirubin secreted?

Bile

55

- Breakdown of conjugated bilirubin by bacteria in the terminal ileum occurs
- Free bilirubin is reabsorbed and converted to this
- Excess turns urine dark like cola

Urobilinogen

56

What is urobilinogen released in the urine as?

Urobilin (yellow color)
(free bilirubin -> urobilinogen -> urobilin)

57

What does bile contain?

Bile salts (85%), proteins, phosopholipids (lecithin), cholesterol, and bilirubin

58

What determines the final bile composition?

Active (Na/K ATPase) reabsorption of water in gallbladder

59

Used to make bile salts / acids

Cholesterol

60

What improves water solubility of bile salts?

Bile salts are conjugated to taurine or glycine

61

What are primary bile acids (salts)?

Cholic and chenodeoxycholic

62

What are secondary bile acids (salts)?

Deoxycholic and lithocholic (dehydroxylated primary bile acids by bacteria in gut)

63

Main biliary phospholipid

Lecithin

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Solubilizes cholesterol and emulsifies fats in the intestine, forming micelles, which enter enterocytes by fusing with membrane

Bile

65

When does jaundice occur?

When total bilirubin > 2.5

66

Where is jaundice first evident?

Under the tongue

67

What is the maximum bilirubin?

30: unless patient had underlying renal disease, hemolysis, or bile duct-hepatic vein fistula

68

Causes of elevated un-conjugated bilirubin

Prehepatic causes (hemolysis); hepatic deficiencies of uptake or conjugation

69

Causes of elevated conjugated bilirubin

Secretion defects into bile ducts; excretion defects into GI tract (stones, strictures, tumor)

70

Abnormal conjugation; mild defect in glucuronyl transferase

Gilbert's disease

71

Inability to conjugate; sever deficiency of glucuronyl transferase; high unconjugated bilirubin -> life-threatening disease

Crigler-Najjar disease

72

Immature glucuronyl transferase; high unconjugated bilirubin

Physiologic jaundice of newborn

73

Deficiency in storage ability; high conjugated bilirubin

Rotor's syndrome

74

Deficiency in secretion ability, high conjugated bilirbuin

Dubin-Johnson syndrome

75

All hepatitis viral agents can cause...

Acute hepatitis

76

What can cause fulminant hepatic failure in viral hepatitis?

Can occur with hepatitis B, D, and E (very rare with A and C)

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Viral hepatitis: can cause chronic hepatitis and hepatoma

Hepatitis B, C, and D

78

Consequences of hepatitis A (RNA)

Serious consequences uncommon

79

Hepatitis B: elevated in the first 6 months; IgG then takes

Anti-HBc-IgM (c = core)

80

Hepatitis B vaccination serum

Have increased anti-HBs (s=surface) antibodies only

81

Hepatitis B: patient had infection with recovery and subsequent immunity

Increased anti-HBc and increased anti-HBs antibodies and no HBs antigens (HBsAg)

82

Can have long incubation period; currently most common viral hepatitis leading to liver TXP

Hepatitis C (RNA)

83

Cofactor for hepatitis B (worsens prognosis)

Hepatitis D (RNA)

84

Viral hepatitis: fulminant hepatic failure in pregnancy, most often in 3rd trimester

Hepatitis E (RNA)

85

MCC liver failure

Cirrhosis (palpable liver, jaundice, ascites)

86

Best indicator of synthetic function in patient with cirrhosis

Prothrombin time (PT)

87

- 80% mortality
- Outcome determined by the course of encephalopathy
- Consider urgent liver TXP listing if King's College criteria are emt

Acute liver failure (fulminant hepatic failure)

88

King's college criteria of poor prognostic indicators:
- Acetaminophen-induced ALF

- Arterial pH 6.5, creatinine > 3.4 mg/dL (300 umol/L), grade 3/4 encephalopathy

89

King's college criteria of poor prognostic indicators:
- Non-Acetaminophen-induced ALF

-INR > 6.5
(or any three of the following)
- Age 40, drug toxicity or undetermined etiology, jaundice > 7 d before encephalopathy, INR > 3.5, bilirubin > 17 mg/dL (300umol/L)

90

What causes hepatic encephalopathy?

Liver failure leads to inability to metabolize -> get buildup of ammonia, mercantanes, and false neurotransmitters

91

Causes other than liver failure for encephalopathy

GIB, infection (SBP), electrolyte imbalances, drugs

92

May need to do what in hepatic encephalopathy

May need to embolize previous therapeutic shunts or other major collaterals

93

Treatment: hepatic encephalopathy

- Lactulose
- Limit protein intake (

94

Cathartic that gets rid of bacteria in the gut and acidifies colon (preventing NH3 uptake by converting it to ammonium), titrate to 2-3 stools/d

Lactulose

95

Protein intake suggested for hepatic encephalopathy

96

Hepatic encephalopathy: metabolized by skeletal muscle, may be of some value

Branched-chain amino acids

97

Gets rid of ammonia-producing bacteria from gut

Neomycin

98

Cirrhosis mechanism

Hepatocyte destruction -> fibrosis and scarring of liver -> increased hepatic pressure -> portal venous congestion -> lymphatic overload -> leakage of splanchnic and hepatic lymph into peritoneum -> ascites

99

Management of albumin with paracentesis for ascites

Replace with albumin (1g for every 100 cc removed)

100

Treatment: ascites (from hepatic/splanchnic lymph)

Water restriction (1-1.5 L/d), decreased NaCl (1-2 g/d), diuretics (spironolactone counteracts hyperaldosteronism seen with liver failure), paracentesis, TIPS, prophylactic antibiotics to prevent SBP (norfloxacin; used if previous SBP or current UGIB)

101

Why is aldosterone elevated with liver failure?

Secondary to impaired hepatic metabolism and impaired GFR

102

Progressive renal failure; same lab findings as preener azotemia; usually a sign of end-stage liver disease

Hepatorenal syndrome

103

Treatment: hepatorenal syndrome

Stop diuretics, give volume; no good therapy other than liver TXP

104

What are neurological changes seen with progressive liver failure?

Asterixis; sign that liver failure is progressing

105

What causes postpartum liver failure with ascites?

From hepatic vein thrombosis; has an infectious component

106

Dx / Tx: postpartum liver failure with ascites

Dx: SMA arteriogram with venous phase contrast

Tx: heparin and antibiotic

107

- Fever, abdominal pain, PMNs > 250 in fluid, positive cultures
- Risk factors: prior SBP, UGIB, low-protein ascites

Spontaneous bacterial peritonitis

108

MCC spontaneous bacterial peritonitis

E. coli (#1), pneumococci, streptococci
- Most commonly mono-organism; if not, need to worry about bowel perforation

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Tx: spontaneous bacterial peritonitis

3rd-generation cephalosporins; patients usually respond within 48 hours

110

How do esophageal varices bleed?

Bleed by rupture

111

Treatment: esophageal varices

- Banding and sclerotherapy (95% effective)
- Vasopressin, octreotide
- NGT (h/o CAD)
- Propranolol (no good role acutely)

112

Why is vasopressin good for esophageal varices?

Splanchnic artery constriction

113

Why is octreotide good for esophageal varices?

Decreases portal pressure by decreasing blood flow

114

Has a balloon used to control variceal bleeding; risk of rupture of the esophagus (hardly used anymore)

Sengstaken-Blakemore esophageal tube

115

Esophageal varices: may help prevent re-bleeding; no good role acutely

Propranolol

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Esophageal varices: complication of sclerotherapy

Can get stricture from sclerotherapy; usually easily managed with dilatation

117

Needed for refractory variceal bleeding

TIPS

118

Portal hypertension: pre-sinusoidal obstruction

Schistosomiasis, congenital hepatic fibrosis, portal vein thrombosis (50% of portal HTN in children)

119

What causes 50% of portal HTN in children?

Portal vein thrombosis

120

Portal hypertension: sinusoidal obstruction

Cirrhosis

121

Portal hypertension: post-sinusoidal obstruction

Budd-Chiari syndrome (hepatic vein occlusive disease), constrictive pericarditis, CHF

122

Normal portal vein pressure

123

Act as collaterals between the portal vein and the systemic venous system the lower esophagus (azygous vein)

Coronary veins

124

Leads to esophageal variceal hemorrhage, ascites, splenomegaly, and hepatic encephalopathy

Portal HTN

125

Can decompress portal system

Shunts

126

Used for protracted bleeding, progression of coagulopathy, visceral hypo perfusion or refractory ascites
- Allows integrate flow

TIPS (transjugular intrahepatic portosystemic shunt)

127

Low rate of encephalopathy; need to ligate left adrenal vein, left gonadal vein, inferior mesenteric vein, coronary vein, and pancreatic branches of splenic vein

Splenorenal shunt

128

When do you use splenorenal shunt for hepatic encephalopathy?

Used only for Child's A cirrhotics who present just with bleeding (rarely used anymore)

129

When is splenorenal shunt contraindicated for hepatic encephalopathy?

Refractory ascites, as splenorenal can worsen ascites

130

Child's B or C with indication for shunt

TIPS

131

Child's A that just has bleeding as symptom

Consider splenorenal shunt (more durable); otherwise TIPS

132

Correlates with mortality after open shunt placement

Child-Pugh Score

133

What are the components of the Child-Pugh Score?

Albumin, bilirubin, encephalopathy, ascites, INR

134

Mortality with shunt: Child's A (5-6 pts)

2% mortality with shunt

135

Mortality with shunt: Child's B (7-9 pts)

10% mortality with shunt

136

Mortality with shunt: Child's C (10 pts or greater)

50% mortality with shunt

137

Usually caused by extra-hepatic portal vein thrombosis

Portal HTN in children

138

MCC massive hematemesis in children

Portal HTN in children

139

- Occlusion of hepatic veins or IVC
- RUQ pain, hepatomegaly, ascites, fulminant hepatic failure, muscle wasting, variceal bleeding

Budd-Chiari Syndrome

140

Dx: budd-chiari syndrome

Angiogram with venous phase, CT angiogram; liver biopsy shows sinusoidal dilation, congestion, centrilobular congestion

141

Tx: budd-chiari syndrome

Porta-caval shunt (needs to connect to the IVC above the obstruction)

142

Can lead to isolated gastric varices without elevation of pressure in the rest of the portal system. These gastric varies can bleed.

Splenic vein thrombosis

143

What causes splenic vein thrombosis?

Most often caused by pancreatitis

144

Tx: Splenic vein thrombosis

Splenectomy if symptomatic

145

- Increased LFTs, increase in right lobe of liver, usually single
- Symptoms: fever, chills, RUQ pain, increased WBCs, jaundice, hepatomegaly.
- Can usually diagnose based on CT characteristics

Amebic liver abscess

146

Where does primary infection occur in amebic liver abscess?

Colon - amebic colitis

147

Risk factors: amebic liver abscess

Travel to Mexico, ETOH; fecal-oral transmission

148

What is serology positive for in amebic liver abscess?

Entamoeba histolytica - 90% have infection

149

How does ameba reach the liver to cause liver abscess?

Reaches liver via portal vein

150

What does culture usually reveal in amebic liver abscess?

Cultures of abscess often sterile -> protozoa exist only in peripheral rim

151

Tx: amebic liver abscess

Flagyl; aspiration only if refractory; surgery only if free rupture

152

- Forms cyst (hydatid cyst)
- Positive Casoni skin test, positive serology
- Sheep (carriers); dogs (human exposure); increase in right lobe of the liver

Echinococcus

153

Why do you not aspirate a hydatid cyst (echinococcus)?

Do not aspirate -> can leak out and cause anaphylactic shock

154

What does abdominal CT show in echinococcus (hydatid cyst)?

Ectocyst (calcified) and endocyst (double-walled cyst)

155

When do you do pre op ERCP in echinococcus (hydatid cyst)?

Jaundice, increased LFTs or cholangitis to check for communication with the biliary system

156

Treatment: echinococcus liver abscess

Pre-op albendazole (2 weeks) and surgical removal (intra-op can inject cyst with alcohol to kill organisms, then aspirate out); need to get all of cyst wall

157

What happens if you spill cyst contents in echinococcus?

Anaphylactic shock

158

- Maculopapular rash, increased eosinophils
- Sigmoid colon: primary infection, fine granulation tissue, petechiae, ulcers
- Can cause variceal bleeding

Schistosomiasis

159

Tx: schistosomiasis

Praziquantel and control of variceal bleeding

160

- account for 80% of liver abscess
- Symptoms: fever, chills, weight loss, RUQ pain, increased LFTs/WBCs, sepsis
- increase in right lobe; 15% mortality with sepsis

Pyogenic abscess

161

#1 organism in pyogenic liver abscess

E. coli (GNRs)

162

What causes pyogenic abscess?

Most commonly secondary to contiguous infection form biliary tract
- Can occur following bacteremia from other types of infections (diverticulitis, appendicitis)

163

Dx / Tx: pyogenic liver abscess

- Dx: aspiration
- Tx: CT-guided drainage and antibiotics; surgical drainage for unstable condition and continued signs of sepsis

164

What causes hepatic adenomas?

Women, steroid use, OCPs

165

- 80% are symptomatic, 20% risk of significant bleeding (rupture)
- Can become malignant
- More common in right lobe
- Symptoms: pain, increased LFTs, hypotension (from rupture), palpable mass

Hepatic adenomas

166

Dx: hepatic adenoma

No Kupffer cells in adenomas, thus no uptake on sulfur colloid scan (cold)
- MRI demonstrates a hypervascular tumor

167

Tx: asymptomatic hepatic adenoma

Stop OCPs; if regression, no further therapy is needed; if no regression, patient needs resection of the tumor

168

Tx: symptomatic hepatic adenoma

Tumor resection for bleeding and malignant risk; embolization if multiple and unresectable.

169

- Has central stellate scar that may look like cancer
- No malignant risk; very unlikely to rupture
- MRI / CT scan demonstrates a hypervascular tumor

Focal nodular hyperplasia

170

Dx: focal nodular hyperplasia

Abdominal CT; has Kipper cells; so will take up sulfur colloid on liver scan

171

Tx: focal nodular hyperplasia

Conservative therapy (No resection)

172

Most common benign hepatic tumor

Hemangiomas

173

- Rupture rare; most asymptomatic; more common in women
- Avoid biopsy -> risk of hemorrhage

Hemangiomas

174

Dx: hemangiomas

MRI and CT scan show peripheral to central enhancement
- Appears as hyper vascular lesion

175

Tx: hemangiomas

Conservative unless symptomatic, then surgery +/ pre-op embolization; steroids (possible XRT) for unresectable disease

176

Rare complications of hemangioma

Consumptive coagulopathy (Kasabach-Merritt syndrome) and CHF; these complications are usually seen in children

177

- Congenital; women, right lobe
- Walls have a characteristic blue hue
- Complications from these cysts are rare; most can be left alone

Solitary liver cysts

178

Malignant liver tumors:
- metastases:primary ratio

20:1

179

Most common cancer worldwide

Hepatocellular carcinoma (hepatoma)

180

Risk factors for hepatocellular carcinoma

HepB (#1 cause worldwide), HepC, ETOH, hemochromatosis, alpha1-antitrypsin deficiency, primary sclerosing cholangitis, aflatoxins, hepatic adenoma, steroids, pesticides

181

Not risk factors for hepatocellular carcinoma

Primary biliary cirrhosis, Wilson's disease

182

What have the best prognosis for malignant liver tumors?

Clear cell, lymphocyte infiltrative, and fibrolamellar types (adolescents and young adults)

183

Correlates with tumor size in malignant liver tumors

AFP level

184

5 year survival rate with resection in hepatocellular carcinoma

30%

185

Why are few hepatic tumors resectable?

Secondary to cirrhosis, portohepatic involvement, or metastases

186

Margins for resection in hepatocellular carcinoma

1 cm margins

187

Where is tumor recurrence most likely after resection of hepatocellular carcinoma?

Tumor recurrence most likely in the liver after resection

188

Risk factors: PVC, thorotrast, arsenic -> rapidly fatal

Hepatic sarcoma

189

Management: Isolated colon carcinoma metastases to liver

Can resect if you leave enough liver for the patient to survive; 35% 5-year survival rate after resection for cure

190

Primary liver tumors

Hypervascular

191

Metastatic liver tumors

Hypovascualr