31 Liver Flashcards
1
Q
Hepatic artery variants
A
Right hepatic artery off superior mesenteric artery (most common 20%) - courses behind pancreas, posterolateral to the CBD
Left hepatic artery off left gastric artery (20%) - found in gastrohepatic ligament medially
2
Q
Falciform ligament
A
Separates medial and lateral segments of the left lobe
Attaches liver to anterior abdominal wall
Extends to umbilicus and carries remnant of the umbilical vein
3
Q
Ligamentum teres
A
Carries the obliterated umbilical vein to the under surface of the liver
Extends from the falciform ligament
4
Q
Cantlie’s line (portal fissure)
A
Line drawn from the middle of the gallbladder fossa to IVC
Separates the right and left liver lobes
5
Q
Sections of the liver
A
Right lobe: anterior (8, 5) and posterior (7,6)
Left lobe: left medial section (1, 4) and left lateral section (2,3)
6
Q
Liver segment - I
A
Caudate
7
Q
Liver segment - II
A
Superior left lateral segment
8
Q
Liver segment - III
A
Inferior left lateral segment
9
Q
Liver segment - IV
A
Left medial segment (quadrate lobe)
10
Q
Liver segment - V
A
Inferior right anteromedial segment
11
Q
Liver segment - VI
A
Inferior right posterolateral segment
12
Q
Liver segment - VII
A
Superior right posterolateral segment
13
Q
Liver segment - VIII
A
Superior right anteromedial segment
14
Q
Glisson’s capsule
A
Peritoneum that covers the liver
15
Q
Bare area
A
Area on the posterior-superior surface of the liver not covered by Glisson’s capsule
16
Q
Triangular ligaments
A
Lateral and medial extensions of the coronary ligament on the posterior surface of the liver, made up of peritoneum
17
Q
Portal triad enters via:
A
Segments IV and V
18
Q
Gallbladder lies under:
A
Segments IV and V
19
Q
Relationship of structures within the hepatoduodenal ligament
A
Lateral - CBD
Portal vein (posterior)
Medial - Proper hepatic artery
20
Q
Kupffer cells
A
Liver macrophages
21
Q
Contents of the portal triad
A
Common bile duct (lateral)
Portal vein (posterior)
Proper hepatic artery (medial)
Come together in the hepatoduodenal ligament (porta hepatis)
22
Q
Pringle maneuver
A
Porta hepatis clamping
Will NOT stop hepatic vein bleeding
23
Q
Foramen of Winslow
A
Entrance to the lesser sac Anterior - portal triad Posterior - IVC Inferior - duodenum Superior - liver
24
Q
Portal vein forms from:
A
Superior mesenteric vein joining the splenic vein (no valves)
Inferior mesenteric vein drains into the splenic vein
25
Portal vein branches
2 branches - providing 2/3 of hepatic blood flow
Left - segments II, III, IV
Right - segments V, VI, VII, VIII
26
Arterial blood supply to the liver
Right left and middle hepatic arteries
Middle hepatic artery is a branch of left hepatic artery
Hepatic artery supplies most primary and secondary tumors
27
Hepatic venous drainage
3 hepatic veins - drain into IVC
Left - II, III, superior IV
Middle - V, inferior IV
Right - VI, VII, VIII
28
Variation of the middle hepatic vein
80% drain into left hepatic vein
| 20% drain directly into the IVC
29
What do accessory right hepatic veins drain?
Medial aspect of the right lobe, directly into IVC
30
Blood supply of caudate lobe
Receives separate right and left portal and arterial blood flow
Drains directly into the IVC via separate hepatic veins
31
Alkaline phosphatase origin
Canalicular membrane
32
Where does nutrient uptake occur?
Sinusoidal membrane
33
Where is urea synthesized?
In the liver
34
What coagulation factors are NOT synthesized in the liver?
vWF, factor VIII (endothelium)
35
What vitamins are stored in the liver?
Fat soluble and B12
36
What are the most common problems with hepatic resection?
Bleeding
| Bile leak
37
Which hepatocytes are most sensitive to ischemia?
Central lobular (acinar zone III)
38
What is bilirubin the product of?
Breakdown of hemoglobin
| Hbg --> heme --> biliverdin --> bilrubin
39
How is the water solubility of bilirubin improved?
Conjugated to glucuronic acid (glucoronyl transferase)
| Occurs in the liver
40
What form of bilirubin is actively secreted into bile?
Conjugated bilirubin
41
How is bilirubin processed after it is secreted in bile?
Free bilirubin is created via bacterial breakdown of conjugated bilirubin in the terminal ileum
It is reabsorbed and converted into urobiligen, which is released as urobilin in the urine
42
What causes cola colored urine?
Excess urobilinogen
43
What is the content of bile?
```
Bile salts (85%)
Protein
Phospholipids (lecithin)
Cholesterol
Bilirubin
```
44
What determines the final composition of bile?
Active resorption of water via Na/K ATPase
45
What is cholesterol's role in bile?
Used to make bile salts/acids
46
What are bile salts conjugated to? Why?
Taurine, glycine
| Improves water solubility
47
Primary bile acids (Salts)
Cholic and chenodeoxycholic
48
Secondary bile acids (salts)
Deoxycholic and lithocholic
| Dehydroxylated primary bile acids via bacteria in gut
49
Role of bile in digestion
Bile solubilizes cholesterol and emulsifies fats in the intestine, forming micelles, which enter enterocytes by fusing with the membrane
50
Minimum bilirubin level for jaundice? Where do you see it first?
Bilirubin >2.5
| Under the tongue
51
Maximum bilirubin level?
30
| Unless underlying renal disease, hemolysis or bile duct-hepatic vein fistula
52
Causes of elevated unconjugated bilirubin
Prehepatic - hemolysis
| Hepatic deficiencies of uptake or conjugation
53
Causes of elevated conjugated bilirubin
Secretion defects into bile ducts
| Excretion defects into GI tract (stones, strictures, tumors)
54
Gilbert's disease
Abnormal conjugation
| Mild defect in glucuronyl transferase
55
Crigler-Najjar disease
Inability to conjugate
Severe deficiency in glucuronyl transferase
High unconjugated bilirubin - life-threatening disease
56
Physiologic jaundice of newborn
Immature glucuronyl transferase
| High unconjugated bilirubin
57
Rotor's syndome
Deficiency in storage ability
| High conjugated bilirubin
58
Dubin-Johnson syndrome
Deficiency in secretion ability
| High conjugated bilirubin
59
Fulminant hepatic failure - which viral hepatitis?
B, D and E (rare with A and C)
60
Chronic hepatitis and hepatoma - which viral hepatitis?
B, C and D
61
Hepatitis A
RNA
Fecal/oral
Serious consequences uncommon
62
Hepatitis B
DNA - funny replication with reverse transcriptase
| Associated with both acute and chronic hepatitis
63
Anti-HBc antibodies (hep B)
Core antibody
IgM elevated first 6mo after exposure
IgG >6mo
NOT in vaccination
64
Hep B vaccination
Elevated anti-HBs (surface) antibodies only
65
Elevated anti-HBc antibody
Elevated anti-HBs antibody
Negative HbsAg
Patient had infection with recovery
| Has immunity
66
Hepatitis C
RNA
Long incubation period
Not associated with acute hepatitis - associated with chronic hepatitis
Most common viral hepatitis leading to liver TXP
67
Hepatitis D
RNA
Cofactor for hepatitis B
Worse prognosis
68
Hepatitis E
RNA
| Fulminant hepatic failure in pregnancy (3rd trimester)
69
Most common cause of liver failure?
Cirrhosis (palpable liver, jaundice, ascites)
70
Best indicator of synthetic function in patients with cirrhosis?
Prothrombin time (PT)
71
Mortality in acute liver failure?
Fulminant hepatic failure has 80% mortality
| Outcome determined by course of encephalopathy
72
Criteria for urgent liver transplant listing?
King's college criteria
| Separated between acetaminophen-induced and other
73
King's college criteria for acetaminophen-induced ALF?
```
Arterial pH <7.3 irrespective of coma grade
OR, all of the following:
- INR >6.5
- Creatinine >3.4
- Grade III/IV encephalopathy
```
74
King's college criteria for Non-acetaminophen-induced ALF?
```
INR >6/5
OR, any 3 of the following:
- Age <10 or >40
- Drug toxicity or undetermined etiology
- Jaundice >7 days before encepholopathy
- INR >3.5
- Bilirubin >17
```
75
Why does liver failure cause hepatic encephalopathy?
Inability to metabolize ammonia, mercantanes, and false neurotransmitters
76
Causes, apart from liver failure, for encephalopathy?
GI bleed
Infection (SBP)
Electrolyte imbalance
Drugs
77
Treatment of hepatic encephalopathy?
```
Possible emoblization of previous therapeutic shunts or other major collaterals
Lactulose
Limit protein intake (<70g/day)
Add BCAA to diet
No Abx unless specific infection
Neomycin
```
78
How does lactulose help with hepatic encephalopathy?
Cathartic that gets rid of bacteria in the gut
Acidifies the colon - prevents NH3 uptake by converting it to ammonium
Titrate to 2-3 stools/day
79
How does neomycin help with hepatic encephalopathy?
Gets rid of ammonia-producing bacteria from the gut
80
How does chronic cirrhosis cause ascites?
```
Hepatocyte destruction -->
Fibrosis and scaring of liver -->
Increased hepatic pressure -->
Portal venous congestion -->
Lymphatic overload -->
Leakage of splanchnic and hepatic lymph into peritonium
--> Ascites
```
81
Albumin dose with paracentesis for ascites
1g albumin for every 100cc removed
82
Treatment of ascites
Water restrict ion(1-1.5L/day)
Decreased NaCl (1-2g/day)
Diuretics (spironolactone conteracts hyperaldosteronism seen with liver failure)
Paracentesis
TIPS
Prophylactics for SBP (Norfloxacin - if previous SBP or current UGI bleed)
83
Why is aldosterone elevated with liver failure?
Impaired hepatic metabolism
| Impaired GFR
84
Hepatorenal syndrome
Progressive renal failure due to hepatic failure (end-stage)
Same lab findings as prerenal azotemia
Tx: Stop diuretics, give volume; liver TXP
85
Asterixis
Neurological changes due to liver failure
| Sign that it is getting worse
86
Postpartum liver failure with ascites
Due to hepatic vein thrombosis - infectious component
Dx: SMA arteriogram with venous phase contrast
Tx: Heparin + abx
87
Diagnostic criteria for SBP?
Fever
Abdominal pain
PMNs >250 in fluid
+/- positive cultures
88
Bacteria causing SBP?
E. coli
Pneumococci
Streptococci
89
Differentiating between SBP and bowel perf?
SBP is mono-organism
| If it is a poly infection - consider perf
90
Risk factors for SBP?
Ascites (required)
Prior SBP
Upper GI bleed (variceal hemorrhage)
Low-protein ascites
91
Treatment of SBP?
3rd generation cephalosporins
| Patients respond in 48 hours
92
Treatment of esophageal varices
Banding and sclerotherapy (95% effective)
Vasopressin/octreotide (temporizing)
Sengstaken-Blakemore esophgeal tube
Propranolol (prevent re-bleed, not useful acutely)
TIPS for refractory bleeding
93
Vasopressin - MOA in esophageal varices
Splanchnic artery constriction
| If patient has hx of CAD - add NTG
94
Octreotide - MOA in esophageal varices
Decreases portal pressures by decreasing blood flow
95
Late complication from sclerotherapy? Tx?
Strictures
| Dilation
96
Causes of portal hypertension?
Pre-sinusoidal obstruction - schistosomiasis, congential hepatic fibrosis, portal vein thrombosis
Sinusoidal obstruction - cirrhosis
Post-sinusoidal obstruction - Budd-Chiari syndrome, constrictive pericarditis, CHF
97
Normal portal vein pressure
<12 mmHg
98
Which hepatic vein acts as collaterals between the portal vfein adn systemic venous system?
Coronary veins - portal vein to veins of lower esophagus (azygous vein)
99
Complications of portal hypertension?
Esophageal variceal hemorrhage
Ascites
Splenomegaly
Hepatic encephalopathy
100
Role of shunts in portal hypertension? Complications?
Decompress the portal system
| Can increase risk of encephalopathy (bypassing the metabolism of liver)
101
Transjugular intrahepatic portosystemic shunt
TIPS
Indication: protracted bleeding, progression of coagulopathy, visceral hypoperfusion, refractory ascites
Allows antegrade flow
Complication - encephalopathy
102
Splenorenal shunt
Lower rate of encephalopathy
Ligate left adrenal vein, left gonadal vein, IMV, coronary vein and pancreatic branches of splenic vein
Indications - Child's A cirrhotic presenting with just bleeding
CI: refractory ascites (can make it worse)
103
Child's B or C with indication for shunt
Treat with TIPS
104
Child's A with just bleeding symptoms
Consider splenorenal shunt (more durable)
| Otherwise TIPS
105
Child-Pugh Score
Assessment of liver failure
Assesses:
- Albumin (>3.5 - 3-3.5 - <3.0)
- Bilirubin (<2.5 - 2.5-4 - >4)
- Encephalopathy (none - minimal - refractory)
- Ascites (none - tx with meds - refractory)
- INR (<1.7 - 1.7-2.3 - >2.3)
Give 1-2-3 points for each category
A - 5-6; B - 7-9; C 10+
106
Association of Child-Pugh Score with Shunt placement
Correlates with mortality after open shunt placement
Child's A - 2%
Child's B - 10%
Child's C - 50%
107
Budd-Chiari syndrome
Occlusion of hepatic veins of IVC
Sx: RUQ pain, hepatosplenomegaly, ascites, fulminant hepatic failure, muscle wasting, variceal bleeding
Dx: angiogram with venous phase, CT angiogram; liver bx (sinusoidal dilation, congetsion, centrilobular congestion)
Tx: Porta-caval shunt (connecting to IVC above the obstruction)
108
Splenic vein thrombosis
Cause: Pancreatitis
Sx: Isolated gastric varices (without elevation of the rest of the portal system pressure), UGI bleed of the varices
Ts: Splenectomy if symptomatic
109
Amebic liver abscess
```
Single in right lobe of liver
Entamoeba histolytica
Reaches liver via portal vein
Culture of abscess negative
Dx: CT (rim enhancing lesion)
Tx: Flagyl, aspiration (if refractory), surgery (free rupture)
```
110
Echinococcus liver abscess
Hydatid cyst
Positive Casoni skin test, positive serology
Right love of liver
Dx: CT (calcified, double-walled cyst); ERCP (jaundice, increased LFTs, cholangitis to assess for communication with biliary tract)
Tx: pre-op albendazole (2 weeks), surgical removal (inject cyst with alcohol, get entire cyst wall)
DO NOT aspirate - anaphylactic shock
111
Schistosomiasis liver abscess
Maculopapular rash, increased eosinophils
Sigmoid colon infection (fine granulation tissue, petechiae, ulcers)
Can cause variceal bleeding
Tx: praziquantel
112
Pyogenic liver abscess
Sx: Fever, chills, wt loss, RUQ pain, increased LFTs, WBC, sepsis
Right lobe
E. coli
Contiugous infection from biliary tract or bacteremia
Dx: aspiration
Tx: CT-guided drainage and abx; surgical drainage for unstable condition and continued sepsis
113
Benign liver tumors
Hepatic adenomas
Focal nodular hyperplasia
Hemangioma
Solitary cyst
114
Hepatic adenoma
Steroids/OCP
Sx: Pain, increased LFT, hypotension (rupture), palpable mass
Dx: Negative sulfur colloid scan (no Kupffer cells), MRI hypervascular tumor
Tx:
Asymptomatic - stop OPCs, if no regression --> resection
Symptomatic - resection for bleeding/malignancy risk; embolization if multiple and unresectable
115
Sulfur colloid scan
Used to liver tumors
Kupffer cells uptake sulfur colloid - positive scan
Hepatic adenomas have NO kupffer cells
Focal nodular hyperplasia does have kupffer cells
116
Focal nodular hyperplasia
Central stellate scar - looks like cancer
No malignancy risk, unlikely to rupture
Dx: Abdomina CT, positive sulfur colloid scan (has kupffer cells), hypervasular tumor
Tx: conservative (no surgery)
117
Hemangioma
Rare rupture
Avoid biopsy - risk of hemorrhage
Dx: MRI/CT - peripheral to central enhancement; hypervascular lesion
Tx: symptomatic - surgery +/- pre-op emobolization; steroids and possible XRT for unresectable
118
Kasabach-Merritt syndrome
Consumptive coagulopathy due to hemangioma (rare, children)
119
Rare complications of hemangioma seen in children?
```
Consumptive coagulopathy (Kasabach-Merritt)
CHF
```
120
What type of CT do you use to assess the liver?
Triple phase
- Native
- Portal
- Arterial
121
Solitary liver cysts
```
Congenital
Women
Right lobe
Characteristic blue hue
Tx: nothing
```
122
Hepatoma (HCC)
Most common cancer worldwide
| AFP level correlates with tumor size
123
Risk factors for HCC
Hep B, Hep C, ETOH, hemochromatosis, aslpha-1-antitrypsin deficiency, primary sclerosing cholangitis, alfatoxins, hepatic adenoma, steroids, pesticides
NOT - primary biliary cirrhosis, Wilson's disease
124
Best prognosis forms of HCC
Clear cell
Lymphocyte infiltrative
Fibrolamellar type (adolescent, young adults)
125
Tumor marker for HCC
AFP
126
Margins for HCC
1cm
127
Risk factors for hepatic sarcoma
PVC, thorotrast, arsenic
128
Isolated colon CA metastases to liver - treatment
Resection if there is >35% of (good) liver remaining
129
Primary liver tumors CT apperance
Hypervascular
130
Metastatic liver tumors CT apperance
Hypovascular
