Liver 2 Flashcards
In the past pyogenic liver abscesses were a result of what?
infections from the intestinal tract such as acute appy and diverticulitis
which spread to liver via portal circulation
What are causes of pyogenic liver abscesses now?
usually from biliary tract dx or cryptogenic
Most common liver abscesses seen in US?
pyogenic liver abscess
What bugs do we see with pyogenic liver abscess?
40/40% mono/polymicrobial
20% culture negative
Most common bacteria seen in pyogenic liver abscesses?
2/3 are gram negative bacteria
e.coli in 2/3 of cases (strept. faecalis, klebsiella other bugs)
Pyogenic liver abscesses can be single or multiple but tend to be found on which side of liver more frequently?
right lobe
Clinical presentation and labs seen in someone w/pyogenic liver abscess?
clinically; RUQ pain, fever, jaundice (1/3)
labs: leukocytosis, increased ESR, ALK
What do we see on US of suspected pyogenic liver abscess?
round or oval hypoechoic lesions w/well defined borders
variable number of internal echoes
Initial therapy for pyogenic liver abscess?
IV abx for at least 8 weeks
(need gram neg and anaerobic coverage)
surgical drainage laparoscopically or open may become necessary if initial therapy fails
Do we do catheter drainage of pyogenic liver abscess?
effective in small number of pts
fluid is usually viscous and does not drain well
Distribution of pyogenic liver abscesses in the liver?
75% right lobe
20% left lobe
Causes of pyogenic liver abscesses?
infections from biliary tree are most common identifiable cause
obstruction causes bile stasis, bacterial overgrowth, and infection and extention into liver
What is pyelophlebitis?
the portal venous system drains the GI system; thus any infectious d/o of GI tract can result in ascending portal vein infection
Most common organisms cultured from pyogenic liver bascesses?
e.coli
klebsiella
Pyogenic liver abscesses tend to occur in what age group?
50-60s
Abx for pyogenic liver abscesses?
ampicillin + metronidazole
Most common type of liver abscess worldwide?
amebic liver abscess
Male vs female predominance of amebiasis?
10;1 male
Amebic liver abscess caused by?
ameoba histolytica
affecting 10% of world’s population
Who gets amebiasis?
males 20-40 with travel to endemic tropical areas
mexico, india, central america
Some risk factors for contracting amebiasis?
immunosuppression
heavy etoh use
Life cycle of entamoeba histolytica?
exists as cysts outside body (vegetative form)
cyst passes thru stomach and small bowel
transforms into a trophozoite in colon
invades colonic mucosa, forming flask-shaked ulcers
carried to liver
How does abscess of amoeba hystolitica appear?
common in R-lobe of liver
has a necrotic central portion that contains thick-reddish brown pus like material–:> anchovy paste
Anchovy or chocolate like paste is assc w/?
amebiasis from entamoeba histolytica
Should be considered in pts who travel to endemic areas that have RUQ pain, fever, hepatomegaly, hepatic abscess;
amebiasis
Labs seen in amebiasis?
elevated LFTs and jaundice are rare
mildly elevated ALK
How is E. histolytica obtained?
fecal oral route
ingesting cyst from environment
What’s the anchovy paste seen in E. histolytica abscess?
blood and liquified liver tissue
On CT, these abscesses tend to be peripherally located, round, non enhancing rim with peripheral edema;
amebic liver abscess
located peripherally bc it ameba can’t degrade glisson’s capsule
Treatment of choice for an amebic liver abscess?
750 mg metronidazole 3x/day for 7-10 days
curative in 90%
clinical improvement seen in 3 days
When do we consider aspiration for amebic liver abscesses?
abscesses larger than 5 cm
failure of abx therapy
abscesses in left liver
(these abscesses ass w/higher risk of rupture)
Most common complication of amebic liver abscess?
rupture into peritoneum, pleural cavity, pericardium
size of abscess is greatest risk factor for rupture
What causes hydatid cysts?
infection by the tapeworm echinococus granulosus
Hydatid cysts are more common in what areas of the world?
sheep-grazing areas (New Zealand, Africa, Greece, Spain)
Hydatid cysts affect what organs?
liver 70% of the time
30% lung, spleen, brain, bones
A hydatid cyst has how many layers?
2 layers
Where do we find most hydatid cysts in the liver?
75% right liver
How do we describe hydatid cysts on imaging?
well-defined hypodense lesions with a distinct wall
Treatment of hydatid cysts?
surgical–> due to high risk of rupture and secondary infection
Initial treatment for small asymptomatic cysts?
albendazole
During surgical resection of a hydatid cyst, care must be taken to ?
not rupture the cysts
cyst contents can induce an anaphylactic reaction
How does Ascaris lumbricoides get to the liver?
common in Far East
retrograde movement in the bile ducts from GI tract
What’s the complications of Ascariasis?
can serve as nidus for intrahepatic gallstones
can block CBD
can cause cholangitis
Tx for ascariasis?
piperazine citrate
mebendazole
albendazole
ERCP extraction of worm
Tx for hepatic schistosomiasis?
praziquantel 40-75 mg/kg as single dose
Cornerstone of current antiviral therapy for Hep b?
pegylated interferon
tenofovir/entecavir
Side effects of pegylated interferon?
flu like sx, mood changes
bone marrow suppression
stimulation of autoimmunity
Leading indication of liver transplant in US, Europe and Japan?
cirrhosis due to Hep C
What are some common benign liver lesions?
cysts
adenomas
FNH
hemangiomas
This benign liver lesions seen in women 20-40 and often associated w/steroid use such as chronic oral contraceptive pills:
hepatic adenoma
Female to male ratio of hepatic adenomas?
10;1 female
Histologically this benign liver lesion is described as cords of benign hepatocytes containing increased glycogen and fat:
hepatic adenoma
How does a hepatic adenoma appear on CT?
well-circumscribed heterogenous mass w/early enhancement during the arterial phase
This benign liver lesion can be seen in premenopausal women older than 30 and are typically solitary, although multiple lesions can occur:
adenomas
Prior or current use of estrogens is a risk factor for this benign liver lesion:
hepatic adenomas
Why is it recommended we surgically remove hepatic adenomas?
carry a significant risk of spontaneous rupture (10-25%)
risk of malignant transformation to HCC
What do we see on MRI of suspected adenoma?
well demarcated heterogenous mass containing fat or hemorrhage
What are two risks associated with hepatic adenomas?
spontaneous intraperitoneal rupture
transformation to HCC
How do we handle someone who has a spontaneous intraperitoneal rupture from a hepatic adenoma?
hepatic artery embolization if available
once stabilized and resuscitated–> laparotomy and resection of mass indicated
How do we manage symptomatic vs asymptomatic hepatic adenomas?
asymptomatic pts on OCP–> can be observed after cessation of OCP
symptomatic pts–> mass needs to be removed
On CT you see a well circumscribed lesion with a central scar, what is it?
benign liver lesion; FNH
2nd most common benign liver tumor and mostly found in young women:
FNH
This liver mass is characterized by a central fibrous scar with radiating septae;
FNH
What is the central scar seen in FNH?
often contains a large artery that branches out into multiple smaller arteries in a spoke wheel pattern
What causes FNH?
theory unknown
speculated to arise from vascular malformations
What do we see on imaging of CT and MRI of suspected FNH?
homogenous mass w/central scar that enhances rapidly on arterial phase
Can FNH progress to malignancy?
NO
What does CT show in someone suspected of having FNH?
rapid enhancement on arterial phase
isodense or invisible in background of liver on venous phase
Unlike adenomas, FNH do NOT:
rupture spontaneously
do not progress to malignancy
Surgical tx for FNH?
management is usually reassurance
sx can be recommended when pts symptomatic or HCC cannot be excluded
When either hepatic adenomas or FNH are suspected, what medications should be stopped?
OCPs
This is the most common benign liver tumor:
hemangiomas
Most common benign liver tumors?
hemangiomas
Age and sex distribution of hemangiomas?
3;1 female
approx. age 45
Do hemangiomas spontaneously rupture?
RARE RARE
These benign liver lesions are described as large endothelial line vascular spaces and represent congenital vascular lesions that contain fibrous tissue and small blood vessels that eventually grow;
hemangiomas
How are most hemangiomas discovered?
incidentally w/little clinical significance
On biphasic CT how do we describe hemangiomas?
asymmetrical nodular peripheral enhancement that is isodense w/large vessels
exhibit progressive centripetal enhancement fill-in over time
What liver lesions shows a pattern of peripheral nodular enhancement?
hemangiomas
This is an associated syndrome associated w/hemangiomas:
Kasbach-Merrit syndrome
WHat’s Kassbach-Merrit syndrome?
assc w/ hemangiomas
thrombocytopenia
consumptive coagulopathy
These lesions show a typical peripheral nodular enhancement pattern:
hemangiomas
Do we biopsy hemangiomas?
NO, dangerous
biopsy is not recommended
What’s the natural hx of a liver hemangioma?
normally a benign course
most remain stable over long periods of time
low risk of rupture or hemorrhage
When do we resect hemangiomas?
rupture
significant change in size
development of Kassbach-Merrit syndrome
Hemangiomas can be seen in kids, and large hemangiomas can cause this in children:
CHF due to arterio-venous shunting
Symptomatic hemangiomas in children are treated how?
therapeutic embolization
medical therapy for CHF
resection may be necessary for symptomatic lesions or rupture
This makes up 12% of all pediatric liver tumors:
hemangiomas
Most common primary malignancy of the liver?
HCC
Assc risk factors with HCC?
HBV infection
cirrhosis
smoking
etoh use
Most common malignant tumor seen in the liver?
metastatic colorectal cancer
Major risk factors for HCC?
hep b/c
etoh cirrhosis
hemochromatosis
NASH
HCC are typically hypervascular with blood supplied primarily from?
hepatic artery
How do HCC lesions appear on CT?
hypervascular on the arterial phase
hypodense during delayed phase
HCC has a tendency to invade what structure?
portal vein
presence of an enhancing portal vein thrombus is highly suggestive of HCC
Most cases of HCC are related to what?
HBV infection; 50-55%
HCV infection; 20-25%
This is a powerful hepatotoxin produced by aspergillus species, which acts as a carcinogen and increases risk of HCC:
aflatoxin
Classic presentation of someone with HCC?
male 50-60
RUQ pain + weight loss + palpable mass
What tumor marker can be helpful in assessment of HCC?
AFP
AFP > 20 ng/ml seen in 75% of cases of documented HCC
When do we use AFP levels in someone with HCC?
used to monitor treated pts with recurrence
Classic features of HCC on MRI or CT?
arterially enhancing mass with washout of contrast in delayed phases
Where does HCC normally metastasize to?
lung
bone
peritoneum
Why do we need a preop chest CT in pts with HCC?
normally mets to lung and pts are usually asymptomatic
What’s the treatment of choice for HCC?
liver resection
Other treatment options for HCC that’s not surgical?
ablative techniques
embolization
liver transplant
In which classes of Child-Pugh do we offer surgery for HCC?
Class A
Class B questionable
No to class C
Do we use the TNM staging system for HCC?
NO
it does not accurately predict survival
liver function not taken into account
TNM relies on pathology which is usually not present in HCC
What tx option has the highest long term survival for HCC?
complete excision of HCC by hepatectomy or partial hepatectomy and liver transplant
*** 10-20 % of pts are considered to have resectable disease
These patients with HCC do not tolerate resections;
pts w/Child Pugh Class B/C
pts w/portal htn
What’s percutaneous ethanol injection?
useful technique to ablate small tumors in liver
This is a variant of HCC?
fibrolamellar HCC
How is fibrolamellar HCC different from HCC?
seen in younger pts without hx of cirrhosis
well demaracted, with central fibrotic scar (makes it difficult to distinguish from FNH)
Fibrolamellar HCC is not assc with elevated AFP, but produces high levels of?
neurotensin
WHich has a better progonosis HCC or Fibrolamellar HCC?
fibrolamellar HCC
but recurrence is common (80%)
This is the second most common primary malignancy in the liver:
cholangiocarcinoma (bile duct ca)
Where does cholangiocarcinoma usually develop?
can be intra-hepatic or extra-hepatic
40-60% present at biliary confluence
10% present as intra-hepatic liver masses
What’s a Klatskin tumor?
hilar cholangiocarcinoma
originates at wall of bile duct at the hepatic duct confluence
usually presents with obstructive jaundice
Most common risk factors for developing cholangiocarcinomas?
historically PSC, choledocho cystic disease
nowadays HIV, HBV, cirrhosis, DM
Factors associated with poor outcomes in pts with cholangiocarcinoma?
intrahepatic mets
LN mets
vascular invasion
positive margins
Most common primary hepatic tumor of childhood?
hepatoblastoma
almost all cases seen before age 3
Angiosarcomas of the liver are assc with what ?
vinyl chloride
thorotrast
The most common malignant tumors of the liver are?
metastatic lesions
mostly from GI due to drainage of GI into portal vein
For metastatic colorectal cancer to the liver do we resect?
mets from colon isolated to the liver can be resected with potential for long-term survival and cure
For primary liver cancers or hepatic mets, gold standard treatment option is?
hepatic resection
What is the rationale behind advocating for liver transplant in pts with HCC?
most cases of HCC (>80%) arise in setting of cirrhosis
cirrhotic liver does not have enough reserve to tolerate a resection
How many liver transplants performed annually in US?
> 6K
with 1 year survival at 90%
Milan criteria for liver transplant?
showed that survival rates were improved when liver transplant was limited to pts w/:
early stage I/II HCC
w/ one tumor < 5 cm
w/ 3 tumors no larger than 3 cm
absence of vascular invasion or extrahepatic spread
Chemoembolization is most commonly used for unresectable HCC, how is it done?
injecting chemotheropeutic drugs combined with embolization particles into the hepatic artery that supplies the liver tumor
done via a percutaneous femoral approach
Hepatic artery chemoembolization (AKA TACE), has what complications?
liver dysfunction/failure
hepatic abscess
hepatic artery thrombus
This multikinase inhibitor has been approved by FDA for advanced unresectable HCC:
sorafenib
What’s the SHARP trial?
showed survival benefit in pts with unresectable advance HCC with sorafenib
Advantages and disadvantages of vascular stapling devices in liver surgery?
speedy transection, bloodless
cost is a disadvantage
Some steps common to all hepatic surgeries:
make right subcostal incision w/wout left subcostal extension
explore abdomen, place Bookwalter
palpate liver, perform liver US
taken down round and falciform ligaments, expose anterior surface of hepatic veins
for left hepatectomy, divide left triangular ligament
for right hepatectomy, divide right coronary ligament
open gastrohepatic ligament, palpate porta, assess for accessory hepatic arteries
perform cholecystectomy (leave GB and cystic duct intact if involved by tumor)
Pringle maneuver clamps the porta hepatis to control blood loss, but what’s a problem with it?
can cause ischemic damage and reperfusion damage to liver
some advocate 15 mins clamp on and 5 mins clamp off
What is ischemic deconditioning with Pringle maneuver?
brief interruption of blood flow to an organ followed by a short re-perfusion period and then a more prolonged period of ischemia
How much liver remnant is needed in a normal healthy person to prevent liver failure?
25-30% of total liver volume
TACE, ablative therapy, and sorafenib are what type of therapies for HCC?
usually palliative
Most common benign hepatic liver lesions?
hemangioma followed by FNH
How does hemangioma present on imaging?
peripheral nodular enhancement on arterial phase
progressive centripetal fill-in on portal venous phase
This benign liver lesion shows peripheral nodular enhancement on arterial phase and centripetal fill in on portal venous phase;
hemangioma
Most serious complication of a percutaneous liver biopsy?
bleeding
usually presents 4 hrs following percutaneous drainage
pts have hypotension, tachycardia, abdominal pain
tx–> resuscitate w/crystalloids then blood products
For pts with acalculous cholecystitis, who are decompressed with a PCT, do they need an interval cholecystectomy once they improve clinically?
not necessarily
After a cholecystostomy tube is placed, how soon can we see resolution of symptoms?
usually within 24 hrs
Cholecystostomt tubes are not beneficial for what?
gangrene of the gallbladder
perforation of the gallbladder
