Добавил:
Sekretar
kiopkiopkiop18@yandex.ru
t.me/Prokururor I Вовсе не секретарь, но почту проверяю
Опубликованный материал нарушает ваши авторские права? Сообщите нам.
Вуз:
Предмет:
Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3658_Библиотеки_им_академика_М_И_Перельмана.pdf
Chapter12:Embolization of livertumors
http://internalmedicinebook.com
AB
AB
CD
Figure 12.16 Recognition of the accessory
left gastric artery. (A) The accessory left
gastric artery (open arrowheads) arises from
the segment 4 hepatic artery and the right
gastric artery (white arrowheads) arises
from the left lateral hepatic artery. (B) On
portal phase, the segment 3 (black arrows)
and segment 2 hepatic arteries (white
arrows) have their accompanying portal
vein. In contrast, the accessory left gastric
artery does not have the accompanying
portal vein.
Figure 12.17 Recognition of the accessory
left gastric artery. (A) Celiac arteriogram
shows an artery arising from the left hepatic
artery just before the umbilical point
(arrows). It has a rather undulating course
and terminal tortuosity. The right gastric
artery arises from the bifurcation point of
the proper hepatic artery. (B) Selective left
hepatic arteriogram shows ill-defined stain
at the end of the artery (black arrow) in the
background of small multiple nodular tumor
stain in the left hepatic lobe. (C) Selective
angiogram obtained using a microcatheter
shows esophageal (white arrows) and
gastric stain (black arrow). (D) Arterial-phase
scan in 2.5-mm collimation demonstrates
this small accessory left gastric artery in
the fissure for the ligamentum venosum
(arrows).
in 47 of 252 autopsies (17.9%). In contrast, Michels2 reported
an accessory LGA prevalence of only 3% among 200 anatomic
dissections, which suggests the possibility of a lower incidence
in the Western population than in Asian populations.
17,19
Because esophageal and gastric mucosa might be adversely
aected by the infusion of therapeutic agents into the hepatic
19,20
ar tery,
it is important to recognize the accessory LGA and
dierentiate gastric wall stain of the accessory LGA from a
hepatic tumor of the le hepatic lobe.
19
e most common origin of the accessory LGA is the
LHA. Occasionally, the accessory LGA can arise from the
PHA and, rarely, from the RHA or CHA. It is possible to identify an accessory LGA by analyzing the point of branching,
the course of the artery, and the appearance of the peripheral branches. Branching occurs at the ascending segment
of the LHA before the LHA reaches the umbilical point, at
which the LHA divides into segmental branches. In the portal phase, the accessory LGA does not have an accompanying portal vein (Figure 12.16). Peripheral arterial branches
around and in the gastric wall have a characteristic coiled
appearance. In patients with the accessory LGA, the LGA
from the celiac trunk does not have a fundic branch on celiac
arteriography (Figure 12.15). When the accessory LGA is
small, it is necessary to perform selective le hepatic arteriography or selective angiography of the suspected accessory
LGA (Figure12.17). Rarely, the accessory LGA arises from
the LHA as a common trunk with the le IPA, mediastinal
branch, or bronchial artery.
Hepatic falciformartery
e HFA arises from the middle hepatic artery or LHA as a
terminal branch and runs within the hepatic falciform ligament with the umbilical vein. e falciform ligament consists of a double fold of peritoneum located anterior to the
liver, dividing the medial and lateral segments of the le
lobe of the liver. With progression of liver cirrhosis, the falciform ligament in front of the liver is shied to the right
depending on the degree of atrophy of the right hepatic lobe.
erefore, the classic orientation of HFA is the initial short
rightward segment before escaping the le intersegmental
ssure (sometimes in coiled appearance in anteroposterior projection) and long leward and downward segment
before reaching the anterior abdominal wall (Figure 12.1,
Figure12.11, and Figure12.14).21 e HFA provides partial
109
Section III:Primary liver cancers
http://internalmedicinebook.com
ABC
Figure 12.18 The hepatic falciform artery anastomosing with superior epigastric artery of the internal mammary artery. (A) Left hepatic arteriogram shows the
falciform artery in its characteristic appearance (arrows). (B) Its selective angiogram using a microcatheter reveals the anastomosis with a superior epigastric vessel
(arrows). (C) Embolization was successfully performed by casting the artery with glue (arrows).
AB
Figure 12.19 The left inferior phrenic
artery arising from the accessory left
gastric artery as a common trunk.
(A) Celiac angiogram shows the origin
of a non-hepatic artery from the left
hepatic artery (arrows). (B) On selective
angiography, it consists of the left inferior
phrenic artery (white arrows) and the
accessory left gastric artery, producing the
gastric fundus stain (black arrows).
blood supply around the umbilicus and communicates with
branches of the internal mammary and superior epigastric
arteries (Figure12.18).
2,21
e HFA may function as a col-
trunk. e le IPA occasionally arises from the LHA. e le
IPAs from the LHA frequently form a common trunk with the
accessory LGA (Figure12.19).
lateral pathway to the liver in cases of celiac trunk or hepatic
artery occlusion.
e HFA was found in 70% of 200 cadaveric dissections.2
In a prospective study,17 only 62% of the HFA were recognized
by celiac arteriography. e remaining cases were identied on
superselective le hepatic arteriography. e most common
origin of the HFA is segment 4 hepatic artery regardless of the
presence of hepatic arterial variation. In no cases did the HFA
arise from the segment 2 hepatic artery.
17
e clinical signicance of an angiographically patent HFA
is that supraumbilical skin rash may be caused by exposure of
the skin to toxic chemicals during chemoembolization or infusion chemotherapy through this artery.21 ere is a controversy
over whether prophylactic embolization of the HFA is necessary. Usually, the long and thick HFA has a greater chance of
reaching supraumbilical skin area, and needs to be prophylactically embolized. In radioembolization, prophylactic embolization is necessary because non-target administration of
yttrium-90 microspheres into the HFA will result in a highly
localized midabdominal burning sensation for a period of days
or weeks. Microcoils or glue can be used for embolization of
the HFA (Figure12.18).
Left inferior phrenicartery
e two most common origin sites of the IPAs are the aorta
immediately above or adjacent to the celiac trunk and the celiac
Pancreaticoduodenal arteries
e vascular anatomy of the pancreas head and the duodenum
is very complex. Several named arteries, including pancreaticoduodenal arcade, dorsal pancreatic artery, supraduodenal
or retroduodenal artery, contribute to complex ow dynamics
in this region. Adequate bolus injection and proper identication of these vessels may prevent therapy-induced pancreatitis,
duodenal ulceration, or perforation.
e pancreaticoduodenal arcades supply the head of
the pancreas and the C loop of the duodenum, at least one
being anterior and at least one posterior to the head of the
pancreas.2 e anterior pancreaticoduodenal arcade is
formed by the anterior superior PDA, the smaller of the two
end branches of the GDA. e posterior pancreaticoduodenal arcade is formed by the retroduodenal artery (posterior
superior PDA), usually the rst branch of the GDA before or
immediately aer it passes behind the duodenum. e two
arcades either unite with the SMA via separate inferior PDA
given o by the SMA, one for each arcade, or end in a common inferior PDA. e posterior arcades are more cephalad
than the anterior arcades.
e pancreaticoduodenal arcades are the most common
collateral pathways from the SMA to the celiac branches.
Although in most cases both the anterior and posterior arcades
developed as collateral pathways between the SMA and the
110
Chapter12:Embolization of livertumors
http://internalmedicinebook.com
AB
CHA, occasionally one arcade developed as a single channel
(Figure12.6).
8
e posterior PDA arose from the rst branch of the GDA
in 90% of 200 cadevaric dissections, from the RHA in 5%,
from the PHA in 4%, and from the artery being replaced by a
branch from the dorsal pancreatic artery in 1%.2 In a prospective study,17 the incidence of the posterior superior PDA arising from the PHA or its distal branches was 7%. is condition
was particularly prevalent in patients with a variant hepatic
the cystic artery, PDA, and RHA.25 e right and le intrahepatic bile ducts are surrounded by a vascular plexus supplied
from the main RHA and LHA, segmental arteries, GDA, and
accessory hepatic arteries. is plexus is closely associated with
the arteries supplying the caudate lobe. e caudate lobe and
biliary plexus provide collateral connections between the right
and le livers.26 Biliary necrosis is a relatively rare occurrence
because there lies a rich extrahepatic arterial supply for the biliary system.
Figure 12.20 Accessory right hepatic
artery arising from the posterior superior
pancreaticoduodenal arcade formed
between the proper hepatic artery and
the superior mesenteric artery. (A) Celiac
angiogram shows aberrant origin of the
segment 6 hepatic artery from the proper
hepatic artery in unusual configuration
(arrows). (B) Superior mesenteric arteriogram
clearly shows the communicating arcade
(arrows) between the aberrant segment
6 hepatic artery and the posterior inferior
pancreaticoduodenal artery. Therefore, it
can be said that the segment 6 hepatic
artery originates from the posterior superior
pancreaticoduodenal artery.
artery originating from the GDA. Of 13 patients with a variant hepatic artery arising from the GDA, the prevalence of the
posterosuperior PDA was 54% (7 of 13). In other words, the
posterior pancreaticoduodenal arcade is an important route of
hepatic artery variation (Figure12.20).
e supraduodenal artery has been described as a distinctive
artery that may arise from the GDA (27%), CHA (20%), LHA
(20%), RHA (13%), and cystic arteries (10%).22 Anastomoses
with the extrahepatic biliary ductal arterial supply have been
described in gross dissection.
23
Cystic artery and biliaryplexus
Based on the cadaveric dissection of 500 specimens, Daseler
etal.23 reported an incidence of cystic artery arising from a classic location (RHA arising from the PHA) of 72%, with an incidence of accessory or duplicated cystic arteries of 3%. Other
origins of the cystic artery include replaced/accessory RHA
(18%), LHA (7%), CHA (3%), GDA (1%), and several other
unusual origins.24 e cystic artery usually has two branches,
a supercial (peritoneal) branch and a deep (non-peritoneal)
branch (Figure 12.21).24 It may contribute blood supply to
extrahepatic bileducts.
e cystic artery must be identied before transcatheter
management of hepatic tumors to prevent or minimize the
risks of chemical cholecystitis or ischemic or radiation necrosis. erefore, catheterization distal to the cystic artery is recommended. Occasionally, the cystic artery may feed the tumor.
e superselective catheterization of tumor-feeding arteries
from the cystic artery with lack of gallbladder wall staining
allows safe delivery of therapeutic agents (Figure12.21).
e blood supply to the biliary tree is via a microscopic peribiliary plexus that is seldom visualized angiographically. It may
enlarge when it supplies the tumor invading the bile ducts or
major portal vein (Figure12.22 and Figure12.23). e extrahepatic bile duct system is supplied by multiple arteries from
24
Extrahepatic collateral arteries
Extrahepatic collateral arteries (EHCs) commonly supply
hepatic tumors if the tumors are large or peripherally located,
irrespective of the hepatic artery patency (Figure 12.24 and
Figure 12.25).
tration of hepatic tumors can cause adhesion or direct invasion into adjacent organs, including the diaphragm, omentum,
abdominal wall, gallbladder, stomach, colon, adrenal gland, and
kidney, which creates blood supply to the tumors from these
organs. Hepatic artery occlusion or attenuation of peripheral
hepatic arteries due to repeated transcatheter managements
may initiate or exaggerate extrahepatic collateral supply to the
tumors (Figure12.26 and Figure12.27).
EHCs include IPAs (Figure 12.24, Figure 12.26, and
Figure12.27), omental branches (Figure12.27), cystic artery
(Figure12.21), internal mammary arteries (IMAs) (Figure12.25
and Figure12.27), intercostal (Figure12.26) or lumbar arter-
ies, adrenal arteries, gastric arteries, renal or renal capsular
artery (Figure12.26), colic branches from the SMA, and collateral vessels from the GDA or PDAs (Figure12.23).
IPAs, IMAs, and intercostal arteries communicate with each
other and with peripheral hepatic arterial branches through
the diaphragm (Figure12.24, Figure12.25, Figure12.26, and
Figure12.27). e right renal capsular artery, middle adrenal
artery, and inferior adrenal artery run through the hepatorenal ligament and enter the liver.30 e branches of the right
and middle colic arteries may enter the liver through adhesion
between the liver and colon at the paracolic gutter. e RGA
and LGA anastomose with each other and enter the liver via
the lesser omentum. e bile duct artery or collaterals from
the GDA or PDA run through the hepatoduodenal ligament
and enter the liver. e cystic artery may give o a small hepatic artery branch or communicate with the branch of a hepatic artery through the deep branch of the cystic artery at the
27,28
Exophytic growth and extracapsular inl-
28,29
4,27–38
e
111
Section III:Primary liver cancers
http://internalmedicinebook.com
A B
Figure 12.21 Hepatocellular carcinoma
supplied by deep cystic artery and its
selective embolization. (A) Computed
tomography scan shows compression
or direct invasion of the gallbladder
by a tumor (arrows). (B) The common
hepatic arteriogram shows hypervascular
tumor suspected to be supplied by the
hypertrophied cystic artery (arrows).
(C) Selective angiography of the cystic
artery demonstrates tumor stain exclusively
supplied by the deep branch (white
arrows). The superficial branch (black
arrows) did not contribute to the tumor.
(D) Chemoembolization was performed at
DC
the deep branch of the cystic artery.
Figure 12.22 Dilated periportal and
peribiliary collateral network in a patient
with hepatocellular carcinoma invading the
AB
main portal vein and severe arterioportal
shunt. (A) Common hepatic arteriography
demonstrates a diffuse tumor in the right
hepatic lobe invading the main portal vein
and severe arterioportal shunt. Note the
hepatofugal opacification of the main portal
vein (arrows) and its tributaries. (B) After
Gelfoam embolization of the arterioportal
shunt, numerous fine arterial networks
appeared along the central portal vein and
bile ducts, including the hepatoduodenal
ligament (arrows). The tributaries of the
gastroduodenal artery also contribute to
these anastomotic networks.
AB
gallbladder fossa. e omental arteries may enter the liver by
adhesion of the omentum to the liver.
Multiple EHCs can supply a tumor (Figure 12.27). Once
extrahepatic collateral supply develops, the eective control of
the tumors with transcatheter management can be made possible by the proper management of not only the hepatic arterial
112
Figure 12.23 Dilated periportal and
peribiliary collateral vessels along the
hepatoduodenal ligament in a patient with
hepatocellular carcinoma invading the
right portal vein and severe arterioportal
shunt. (A) Celiac arteriogram demonstrates
a diffuse tumor in the right hepatic lobe
invading the right portal vein and severe
arterioportal shunt. Note the hypertrophied
collateral vessel in the hepatoduodenal
ligament (arrows) supplied by the dorsal
pancreatic artery from the splenic artery.
(B) Superior mesenteric arteriogram reveals
additional multiple collateral channels
supplied by the pancreaticoduodenal artery
(arrows).
supply but also extrahepatic collateral supply (Figure12.26).30
31
It is known to be possible to perform chemoembolization
through EHCs with high success rates and safety.27 erefore,
radiologists should become familiar with the spectrum of
EHCs that supply hepatic tumors, the factors that lead to their
formation, and their characteristic imaging appearance at CT
Chapter12:Embolization of livertumors
http://internalmedicinebook.com
ABC
Figure 12.24 Large hepatocellular carcinoma supplied by the right inferior phrenic artery at its initial presentation. (A) Helical computed tomography scan in the
arterial phase shows a large hypervascular tumor at the right hepatic lobe abutting the posterior diaphragm. The arrow indicates the right inferior phrenic artery.
Its hypertrophy is not remarkable. (B) On celiac arteriography, the celiac trunk and hepatic arteries are widely patent. (C) Right inferior phrenic arteriogram shows its
aortic origin and tumor vascularity.
A
C
and conventional angiography to detect them at an early stage.
Delivery of therapeutic materials into EHCs should be performed with a thorough knowledge of the vascular anatomy
and should be performed superselectively with coaxial microcatheters to avoid complications due to non-target delivery.
How to predict:Suggestive ndings
Because selective angiography of individual collateral vessels
is tedious and time-consuming, it is essential to try to determine rst whether or not collateral blood supply is present.27
e initial CT scan provides useful information, and CT signs
of direct invasion into adjacent organs or extracapsular inltration indicate the presence of EHCs. Tumors with an exophytic
growth pattern are prone to collateral vessel development. It
is commonly possible to observe hypertrophied EHCs on CT
scan. Nowadays, multidetector CT scan can frequently show
tumor-feeding branches from EHCs, particularly from the
IMAs and intercostal arteries (Figure 12.25).
show the origin of IPA or middle adrenal artery from the
B
D
37,38
It can also
aorta. us, prior to the chemoembolization procedure, careful review of multidetector CT scan is essential to determine
which EHCs should be interrogated.
Follow-up CT scans are also useful. Aperipheral iodized-oil
27
retention defect within the tumor or delayed development of
viable tumor at the peripheral portion of the treated tumor at
follow-up CT indicates the presence of EHCs (Figure12.26).
In a tumor that recurs aer surgery at the resection margin,
the presence of omental collateral vessels should be suspected
and investigated. Peripheral local recurrence in a patient with
attenuated peripheral hepatic arteries aer repeated chemoembolization is frequently supplied by EHC. e correlation of CT
and angiographic ndings is essential. If a tumor observed at
CT is not demonstrated at hepatic angiography, collateral vessels must be investigated.31 When tumor staining on hepatic
angiograms has a focal defect or a focal iodized-oil retention
defect is noted during hepatic arteriography or iodized-oil infusion, alternative feeder vessels are a possibility (Figure12.25).
When C-arm CT shows defect of tumor staining supplied by
Figure 12.25 Large hepatocellular
carcinoma abutting the anterosuperior
diaphragm supplied by the right internal
mammary artery at its initial presentation.
(A) Helical computed tomography
scan in the arterial phase shows a large
hypervascular tumor replacing segments
4 and 8 abutting the anterosuperior
diaphragm. The arrow indicates
hypertrophied tumor-feeding artery. (B) The
right hepatic artery is replaced by the
superior mesenteric artery. (C) Common
hepatic arteriogram demonstrates a
defect of the tumor stain at the superior
diaphragmatic aspect (arrows). (D) The
defect area is supplied by a phrenic branch
(arrows) from the right internal mammary
artery.
113
Section III:Primary liver cancers
http://internalmedicinebook.com
AB
CD
EF
Figure 12.26 Hepatocellular carcinoma
exclusively supplied by extrahepatic
collateral arteries after repeated sessions of
chemoembolization. (A) The patient had multiple
nodular tumors (black arrows) at the initial
presentation. Note the accessory left gastric
artery (white arrows). (B) Five repeated sessions
of chemoembolization were performed and all
the tumors at the initial presentation showed
complete response. During follow-up, a recurrent
tumor (arrow) developed at segment 7, abutting
the adrenal gland. (C) Celiac arteriogram showed
no tumor stain; however, the peripheral hepatic
arteries were attenuated. (D) With a suspicion
of extrahepatic arterial supply, right inferior
phrenic arteriography was performed. The tumor
was exclusively supplied by a feeder (black
arrow) from the right inferior phrenic artery.
The white arrow indicates a feeder for inferior
phrenic–pulmonary shunt. (E) On follow-up
computed tomography (CT) scan, the treated
tumor showed complete response (white arrow).
However, another recurrent tumor (black arrow)
developed at segment 7 abutting the posterior
diaphragm. (F) The tumor was not supplied
by the hepatic arteries at all. (G) It was totally
supplied by the 11th intercostal artery. Note the
hypertrophied feeding artery (arrow) which arises
from the intercostal artery at the diaphragmatic
attachment site and ascends along the
diaphragm to reach the tumor. (H) There was
a local progression of the treated tumor at the
follow-up CT (not shown) and the residual viable
tumor was supplied by the renal capsular artery
(arrows) from the right renal artery. (I) The renal
capsular artery was selectively catheterized
using a microcatheter and chemoembolization
was performed. (J) Iodized-oil CT scan taken
2 weeks after the procedure shows compact
accumulation of iodized oil in the tumor (arrow).
GH
I J
the hepatic artery, EHCs should be interrogated. Ahypertrophied omental branch or right IPA may be noted on celiac
angiograms (Figure12.27). If the serum alpha-fetoprotein level
is persistently elevated even aer successful devascularization
of the hepatic artery, we recommend an investigation of EHCs
to theliver.
114
Chapter12:Embolization of livertumors
http://internalmedicinebook.com
AB
C D
EF
Figure 12.27 Cholangiocarcinoma
supplied by multiple left-sided extrahepatic
collateral arteries after repeated sessions
of chemoembolization. (A–C) Sequential
computed tomography scans after four
sessions of chemoembolization demonstrate
large subcapsular viable tumor at the left
lateral segment abutting the left anterior
hemidiaphragm at the superior aspect
(arrows). (D) Celiac arteriogram shows
hypertrophied left gastroepiploic artery
(arrows) from the splenic artery. (E) Selective
angiogram of the left gastroepiploic
artery shows multiple tumor feeders and
hypervascular tumor stain in the left hepatic
lobe. (F) On inferior phrenic arteriography,
part of the upper part of the tumor is
supplied by the left inferior phrenic artery
(arrows). (G) On left internal mammary
arteriography, part of the upper part of the
tumor (white arrows) is supplied by a feeder
(black arrow).
G
ere is a close relationship between the tumor location
and possible EHCs.
27,31
Tumors located at the posterior surface of the right lobe and abutting the diaphragm are most
likely to be fed by the right IPA (Figure 12.24). e right
intercostal and lumbar arteries usually supply tumor in the
lateral and posteroinferior aspect of the right lobe and, when
the IPA is attenuated by repeated chemoembolization procedures, reach the territory of the IPA (Figure12.26). Blood
supply from the right IMA is seen when the tumor is located
beneath the anterior part of the diaphragm or abutting the
anterior abdominal wall (Figure 12.25 and Figure 12.27).
Tumors located near the right renal fossa are fed by the right
renal capsular artery or adrenal arteries. Tumors located at
the anterior surface of the right lobe of the liver or at the
lower edge of the right lobe or medial segment of the le
liver are fed by the omental or colic arteries. Potential feeders for the tumors in the lateral segment of the liver are the
le or right gastric arteries, omental arteries from the right
or le gastroepiploic arteries, short gastric arteries, and le
IPA or IMAs (Figure12.27). e cystic artery mainly feeds
tumors located near the gallbladder fossa (Figure12.21), but
it infrequently supplies the tumor in the right lobe or medial
segment of the liver at a distance from the gallbladder fossa
when the hepatic artery is attenuated. Tumors arising in the
115
Section III:Primary liver cancers
http://internalmedicinebook.com
A B
Figure 12.28 Angiographic anatomy of the right inferior phrenic artery. (A) There are multiple tumors (arrowheads) supplied by the right inferior phrenic artery.
Note the typical appearance of the azygoesophageal branch (arrows). (B) Selective angiography shows that the azygoesophageal branch turns at the medial end
of the azyoesophageal recess (black arrow) and courses along the lung base (white arrow). Peripheral pulmonary artery (arrowhead) is opacified due to shunt.
caudate lobe tend to be fed by the right IPA, LGA, and pancreatic arteries. Adjacent EHCs are connected to each other, and
their distribution shows individual variation. Transcatheter
management of an EHC induces redistribution of blood supply in adjacent collateral arteries.
Anatomy of extrahepatic collateral arteries
Inferior phrenic arteries
ere is a close contact between the liver and the diaphragm,
and the blood supply to the diaphragm can reach the liver by
direct adherence. e IPA supplies most of the diaphragm,
including the area in contact with the bare area of the liver.
us, the right IPA is the most common collateral pathway and
accounts for almost half of all EHCs. It anastomoses with the
adjacent arteries, including the internal mammary, intercostal,
Figure 12.29 Hepatocellular carcinoma in the right liver dome. The tumor
(arrowhead) is supplied by an anteromedial limb (arrows) of the left inferior
phrenic artery.
and adrenal arteries.
e right and le IPAs usually originate from the celiac
trunk or directly from the aorta as a common trunk or independent origins (Figure12.1, Figure12.24, and Figure12.27).
Less frequently, they arise from the renal arteries (Figure12.26)
or, rarely, from the le gastric or hepatic arteries (Figure12.19).
With thin-section multidetector CT, its origin and branching
pattern can be directly viewed in most cases. When the IPA
originates from the celiac axis with median arcuate ligament
compression, selective catheterization of the IPA is frequently
dicult. In that case, special techniques using a catheter with a
large side hole39 or microguide wire loop technique40 are quite
useful. Occasionally, the IPA is occluded or severely stenotic and
reconstructed via retroperitoneal anastomosis from the adrenal
artery, pancreatic arteries from SMA or dorsal pancreatic artery,
LGA, or contralateral IPA.41 ese anastomotic pathways can be
used to continue transcatheter treatments of the tumors.
e azygoesophageal branch of the right IPA is frequently
observed and supplies systemic-to-pulmonary shunt. It usually
arises from the right IPA at the proximal portion of the anterior
branch and, coursed medially, undergoes a U-turn at the medial
end of azygoesophageal recess, and then courses laterally along
the costophrenic angle of the lung base (Figure12.28).
35
e anteromedial limb of the le IPA is the most common
tumor-feeding branch and is observed in about half of patients.
It usually supplies the tumor in the ventral portion of the right
liver dome and can be frequently seen on thin-slice CT scan
(Figure12.29).
36
Patients commonly complain of shoulder pain or chest
tightness during embolization of the IPA. Transient pleural eusion, basal atelectasis, pulmonary oil embolism, or
hemoptysis and diaphragmatic weakness may develop aer
the procedure.
30,42
Because the IPA is also a potential source
for collateralization to the pulmonary circulation, the presence or absence of IPA–pulmonary shunt should be determined before delivery of therapeutic material into the IPA
(Figure12.26D).
116
Chapter12:Embolization of livertumors
http://internalmedicinebook.com
tumors. We found that the phrenic branch is the most common side branch of the IMA supplying hepatic tumors
(Figures 12.25D and 12.30).43 It usually arises between the
fourth and sixth intercostal spaces and passes through anterior
pericardial fat, which can be frequently observed on multidetector CT scan. Nowadays, we perform selective angiography of IMA only when tumor-feeding vessels are observed on
CTscan.
Cutaneous complications may occur aer chemoembolization of the IMA. Understanding vascular anatomy of the IMA
and selective catheterization of tumor-feeding arteries is a prerequisite to prevent skin necrosis aer the procedure.
Intercostal and lumbar arteries
Nine pairs of posterior intercostal arteries originate from the
dorsal aspect of the thoracic aorta. ey anastomose with the
anterior intercostal branches of IMA aer giving o the dorsal branch, the collateral intercostal branch, and the muscular branch. Lower posterior intercostal arteries anastomose
with the IPA at the insertion site of the diaphragm. Ahyper-
Figure 12.30 Angiographic anatomy of the right internal mammary artery in
a patient whose right inferior phrenic artery was previously embolized. At the
level of the sixth intercostal space, the internal mammary artery divides into
the musculophrenic (short, thick white arrows) and superior epigastric arteries
(black arrow). The long descending branch indicated by an open arrow is the
pericardiacophrenic artery, which is rarely demonstrated. The phrenic branch
(white arrows) arises from the main trunk of the internal mammary artery just
above the diaphragm. Among multiple branches of the internal mammary
artery, this phrenic branch most commonly supplies hepatic tumors. The
musculophrenic artery gives off the paired anterior intercostal arteries (black
arrowheads) and the ascending phrenic branches (white arrowheads).
trophied intercostal artery may be observed as a dot-like or
linear structure just inferior to the ribs on arterial-phase CT
scans.38 Tumors abutting the inferolateral aspect of the diaphragm are frequently supplied by the posterior intercostal
arteries. e intercostal artery always passes the diaphragm
insertion site to supply the hepatic tumors, abutting the diaphragm and making a sharp upward turn near the costochondral junction (Figure 12.26G).38 Multidetector CT scan can
show a tumor-feeding vessel as an enhancing dot in the upper
intercostal space in half of patients. Amicrocatheter should
be advanced beyond the diaphragmatic insertion to the tho-
Internal mammary arteries
Angiographic anatomy of the IMA supplying hepatic tumors
has been recently investigated in detail (Figure12.30).43 e
IMA usually arises from the proximal part of the subclavian
artery, opposite the origin of the vertebral artery. e pericardiacophrenic artery usually arises above the second intercostal space and gives branches to the pleura, pericardium, and
diaphragm. At the level of the sixth intercostal space, the IMA
divides into two end arteries, the musculophrenic and superior
epigastric arteries. e musculophrenic artery passes obliquely
downward and laterally, behind the seventh, eighth, and ninth
costal cartilages. It gives o two anterior intercostal branches
to each of the seventh, eighth, and ninth intercostal spaces and
vertical diaphragmatic branches, which anastomose with the
branches of the IPA. e anterior intercostal arteries and the
hypertrophied vertical diaphragmatic branches from the musculophrenic artery create a lattice appearance (Figure12.30).
e superior epigastric artery passes vertically downward and
anastomoses with the inferior epigastric artery. It gives o
some branches to the diaphragm, which extend into the falciform ligament of the liver and anastomose with theLHA.
31
In anatomy textbooks, a pericardiacophrenic artery is
described that accompanies the phrenic nerve between the
pleura and the pericardium. However, according to our experience, it rarely reaches the diaphragm and supplies hepatic
racic cage, where a sharp upward turn is seen, to avoid possible
complications such as skin necrosis and spinal infarction.38 e
common levels of the intercostal arteries that supply hepatic
tumors are T10, T9, and T11, in order of frequency.
38
When the right IPA is obliterated by the previous treat-
ment, the ICAs can supply a tumor at the dome of theliver.
Omental arteries
e omental branch (Figure 12.27) from the gastroepiploic
artery (or, in rare cases, from the dorsal pancreatic artery) is
the second most common collateral vessel. Omental branches
usually are small and branch at an acute angle from the gastroepiploic artery. When an omental branch supplies a tumor, it
becomes suciently dilated to be recognizable at celiac angiography.33 erefore, a careful review of celiac angiograms is
a rst step toward detecting the omental branch that supplies
a hepatic tumor. Because the greater omentum is remarkably
mobile, the omental branch can supply a tumor in any intraperitoneal portion of the liver. In patients with severe liver
cirrhosis, the liver shrinks so markedly that an exophytic
tumor in the liver dome surrounded by the omentum can be
supplied by an omental branch with a very long path.27 ese
omental branches arise from the right and le gastroepiploic
arteries (Figure 12.27). e le gastroepiploic artery arises
from the distal splenic artery. Omental branches from the le
117
Section III:Primary liver cancers
http://internalmedicinebook.com
gastroepiploic artery frequently supply an exophytic tumor at
the dome of the right hepaticlobe.
Adrenal arteries
If a tumor extends inferomedially, adrenal arteries can supply the tumor. e adrenal gland has three sources of arterial
supply:a superior adrenal artery that arises from the IPA, a
middle adrenal artery that arises from the lateral aspect of the
aorta at a level between the celiac and renal arteries, and an
inferior adrenal artery that arises from the superior aspect of
the ipsilateral renal artery. Normal adrenal gland staining is
triangular. On inferior phrenic angiograms, superior adrenal
artery and normal adrenal gland staining are usually observed.
erefore, normal adrenal gland staining must not be confused
with tumor staining on inferior phrenic angiograms.
Renal and renal capsular arteries
If a tumor extends posteroinferiorly, it may be fed by the renal
and renal capsular arteries (Figure12.26). e superior capsular artery usually arises together with the inferior adrenal
artery from the renal artery and follows a characteristic tortuous path over the superior pole of the kidney. Perforating
capsular arteries arise from arcuate and interlobular arteries,
which may supply the tumor in contact with the kidney.
vessels, and embolization of the cystic artery may cause cholecystitis or gallbladder infarction.45 Chemoembolization of the
IPA may result in shoulder pain, pleural eusion, basal atelectasis, pulmonary embolization, or diaphragmatic weakness.
30
To avoid these complications, selective catheterization
should be achieved by placing the catheter tip as close as possible to the specic branch or branches supplying a neoplasm.
Second, embolic materials should be infused incrementally to
prevent them from reuxing into a non-target branch. ird,
coils and gelatin-sponge particles may be used to occlude and
protect the territory of the normal distal branches before chemoembolization. Fourth, to reduce pain, it is recommended that
a small amount of 1% lidocaine be injected intra-arterially during embolization.
27
Because terminal branches of adjacent EHCs are anastomosed to each other, multiple EHCs can supply one tumor. If an
EHC is proximally embolized or is complicated by an arterial
spasm during catheterization or if there is a local recurrence
aer chemoembolization of an EHC, adjacent vessels can take
over its territory. For example, a recurrent tumor previously
supplied via the IPA may be supplied by the intercostal or IMA
at a subsequent chemoembolization session. It is important to
catheterize EHCs by using a meticulous technique with microcatheters to prevent spasm or arterial injury and to investigate
the presence or absence of collateral circulation from adjacent
vessels. In advanced stages of hepatic tumors, chemoemboliza-
Gastric arteries
When a hepatic tumor has broad contact with the stomach,
gastric arteries can supply the tumor. e LGA usually arises
from the celiac trunk and infrequently from the supraceliac
aorta. e RGA commonly arises from the PHA and LHA
and infrequently arises from the GDA and CHA. Short gastric
arteries arise from the splenic artery and supply the gastric fundus. Normal stomach stain can oen mimic tumorstain.
Colic branches
When an exophytic tumor is located in the inferior tip of the
right hepatic lobe, the hepatic exure of the colon can be in
close contact with the tumor. Abranch of the SMA, particularly the right or middle colic branch, may supply the tumor
under these conditions. Because a colic branch supplying the
tumor generally traverses the antimesenteric border of the
colon, it is safe to infuse chemotherapeutic agents beyond the
antimesenteric border.
44
Transcatheter management of extrahepatic collateral arteries
When EHCs are chemoembolized, there is a risk of embolizing non-target branches, which can lead to a variety of complications, depending on location.45 Cutaneous problems,
such as itching, erythema, and necrosis, may arise when the
internal mammary, intercostal, or lumbar artery is embolized.
Gastrointestinal erosion, ulceration, or perforation can be
caused by gastric, omental, and colic branch artery embolization. Paraplegia may result from the inadvertent embolization
of spinal branches arising from intercostal or lumbar collateral
tion through EHCs may not improve tumor control, because it
is extremely dicult to embolize multiple feeder vessels from
hepatic arteries and EHCs eectively.
27
References
1. Williams PL, Warwick R. Gray’s Anatomy, 36th edn.
Philadelphia:Saunders,1980.
2. Michels NA. Blood Supply and Anatomy of the Upper Abdominal
Organs. Philadelphia:JB Lippincott, 1955; pp. 152–154,
256–259, 374–375.
3. Song SY, Chung JW, Yin YH, etal. Celiac axis and common
hepatic artery variations in 5002 patients:Systematic analysis
with spiral CT and DSA. Radiology 2010; 255:278–288.
4. Soo CS, Chuang VP, Wallace S, etal. Treatment of hepatic
neoplasm through extrahepatic collaterals. Radiology 1983;
144:485–494.
5. Bron KM, Redman HC. Splanchnic artery stenosis and
occlusion:Incidence, arteriographic and clinical manifestations.
Radiology 1969; 92:323–328.
6. David CL, Harold AB. High incidence of celiac axis narrowing
in asymptomatic individuals. AJR Am J Roentgenol 1972;
116:426–429.
7. Park CM, Chung JW, Kim HB, etal. Celiac axis
stenosis:Incidence and etiologies in asymptomatic individuals.
Korean J Radiol 2001; 2:8–13.
8. Song SY, Chung JW, Kwon JW, etal. Collateral pathways in
patients with celiac axis stenosis:Angiographic-spiral CT
correlation. Radiographics 2002; 22:881–893.
9. Kwon JW, Chung JW, Song SY, etal. Transcatheter arterial
chemoembolization for hepatocellular carcinomas in
patients with celiac axis occlusion. J Vasc Interv Radiol 2002;
13:689–694.
118