Chapter 31: Liver Flashcards
1
Q
Right hepatic artery variants
A
Off SMA (#1 hepatic artery variant, 20%) courses behind pancreas, posterolateral to the common bile duct
2
Q
1 hepatic artery variant
A
Right hepatic artery off SMA
3
Q
Left hepatic artery variant
A
Off left gastric artery (about 20%) - found in gastrohepatic ligament medially
4
Q
Separates medial and lateral segments of the left lobe; attaches liver to anterior abdominal wall; extends to umbilicus and carries remnant of umbilical vein
A
Falciform ligament
5
Q
What does the falciform ligament contain?
A
Remnant of umbilical vein
6
Q
Carries the obliterated umbilical vein to the undersurface of the liver; extends from the falciform ligament
A
Ligamentum teres
7
Q
Line drawn from the middle of the gallbladder fossa to IVA ; separates right and left liver lobes
A
Portal fissure or Cantlie’s line
8
Q
Liver segments
A
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
Q
Liver segment: 1
A
Caudate
10
Q
Liver segment: 2
A
Superior left lateral segment
11
Q
Liver segment: 3
A
Inferior left lateral segment
12
Q
Liver segment: 4
A
Left medial segment (quadrate lobe)
13
Q
Liver segment: 5
A
Inferior right anteromedial segment
14
Q
Liver segment: 6
A
Inferior right posterolateral segment
15
Q
Liver segment: 7
A
Superior right posterolateral segment
16
Q
Liver segment: 8
A
Superior right anteromedial segment
17
Q
Peritoneum that covers the liver
A
Glisson’s capsule
18
Q
Area on the posterior-superior surface of liver not covered by Glisson’s capsule
A
Bare area
19
Q
Lateral and medial extensions of the coronary ligament on the posterior surface of the liver; made up of peritoneum
A
Triangular ligaments
20
Q
Where does the portal triad enter?
A
Segments 4 and 5
21
Q
Where does the gallbladder lie?
A
Segments 4 and 5
22
Q
Liver macrophages
A
Kupffer cells
23
Q
What composes the portal triad?
A
Common bile duct (lateral), portal vein (posterior), and proper hepatic artery (medial); come together in the hepatoduodenal ligament (porta hepatis)
24
Q
Porta hepatis clamping; will not stop hepatic vein bleeding
A
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
64
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)
77
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
109
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
116
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
