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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3733_Библиотеки_им_академика_М_И_Перельмана.pdf
Difficult problems for patients are lesions in the chest wall or operated breast
after the standard therapy for breast cancer. Patients may see the lesions and
or identify them by touch. Usually, they cause intolerable pain, massive
bleeding, and infection and seriously restrain the patient’s activity. They may
invade the mediastinum or form nodular lesions in the lung. Sometimes,
surgical resection is necessary to improve symptoms, but it is usually
ineffective.
8,9
A recent advance that has the potential to control tumor growth and
active bleeding has been the efficient transarterial administration of drugs
(anthracycline, cisplatin, docetaxel) with embolic material. Currently, greater
precision is provided during the treatment of individual lesions due to
relatively recent advances in angiography, such as superselective
microcatheterization and calibrated microspheres.
DEVICES AND MATERIALS
Catheter System
A 4-Fr guiding catheter system is adequate for a transfemoral or transbrachial
approach. A Cobra catheter (Terumo, Tokyo) is the first choice for femoral
access with less risk of intimal dissection of the aortic wall or occlusion of
the bronchial arteries. The Michelson’s shape or Shepherd hook type
(Terumo, Tokyo) should be the second choice because they provide (higher)
risk of intimal damage or temporary occlusion of the orifice of the bronchial
artery. A coaxial microcatheter is mandatory for safe and selective catheter
insertion. It is extremely important to avoid spasm or temporary occlusion of
the bronchial artery. The maintenance of free antegrade flow through the
blood vessels is key for effective embolization using flow-directed spherical
embolic material.
The use of microcatheters is of particular importance when embolizing
the right intercostobronchial trunk. Exclusive superselective catheterization
of its bronchial branch will avoid potential occlusion of intercostal branches,
which may supply the anterior spinal artery.10 The embolization of the
anterior spinal artery is associated with paraplegia.
Antineoplastic Agent
Different kinds of antineoplastic agents are necessary. Necrotic effects or
tumor shrinkage in the mediastinal or pulmonary tumor cannot be expected
by embolization alone. The anticancer drugs and their combination are
selected according the tumor types or patients’ treatment history or allergic
reaction. Cisplatin, docetaxel, fluorouracil, anthracycline, or their
combination is usually used for primary lung cancer. The total dose of
antineoplastic agent can be reduced with selective tumor chemoembolization
compared to systemic chemotherapy. We typically perform three sessions on
average of chemoembolization.
Embolic Material
The spherical embolic material is the only option among the microparticles.
Embolic materials that may cause proximal or permanent occlusion are not
recommended. Polyvinyl alcohol (PVA) is not suitable because of the
tendency of proximal occlusion. Glue is not suitable due to permanent
occlusion. Liquid material such as Lipiodol
11
is potentially dangerous for
normal tissue (skin necrosis or damage). Metallic coils will close the arterial
access and make it impossible for the sequential procedures, which are
always necessary. HepaSphere (QuadraSphere; Merit Medical Systems, Inc.,
South Jordan, Utah), Embosphere (Merit Medical Systems, Inc., South
Jordan, Utah), Embozene (CeloNova BioSciences, Inc., San Antonio, Texas),
and Bead Block (Biocompatibles UK Ltd., Farnham, Surrey, United
Kingdom) are spherical embolic materials. HepaSphere seems suitable
because of its low irritability. The preferable size is 50 to 100 μm in dry state.
HepaSphere is an expansible microsphere. The rate of expansion depends on
the sodium concentration of the solution. When it contacts with physiologic
saline and nonionic contrast material, it becomes four times and six times
larger, respectively. The HepaSphere microsphere mixed with the solution
with 10% of sodium chloride and nonionic contrast material (1:4) is two
times larger. Five milliliters of this solution is put into the 25 mg of vial 10
minutes before use. Further expansion of microsphere up to four times can be
expected in the arterial occlusion point. It results in the tight occlusion of the
vessel.
Calibrated microspheres seem to improve the efficacy in arterial
occlusion at the point of tumor vasculature. Drug-eluting microspheres do not
have enough record regarding safety or efficacy. There are no reports to use
drug-eluting microspheres for extrahepatic lesions. Our clinical experience is
also limited regarding the drug-eluting HepaSphere for mediastinal and chest
wall lesions. The role of embolic material is not only for the ischemic effect
but also as modulator of chemotherapeutic agents, which can then remain
longer in the target lesion than with simple infusion. We are planning to do
an animal study to confirm hypothesis. However, it is common to obtain
better clinical result from the combination use of antineoplastic agents and
microspheres than the solo infusion of drugs.
ANATOMY
Mediastinal Circulation
The main artery for mediastinal circulation is the bronchial artery. There are
many variations of bronchial arterial branching from the aorta.12 The details
of the vascular anatomy are well described in the Chapter 18 (“Bronchial
Artery Embolization” for hemoptysis management). Hilar lymph nodes and
mediastinal tumors are generally supplied by this artery. Lung tumors are
also fed by the bronchial artery.1 The right bronchial artery usually shares a
common trunk with the right upper intercostal artery.
The small branches of internal thoracic arteries on both sides may feed
the anterior part of the mediastinum. The small branches from the
costocervical and thyrocervical arteries may also feed the upper part of the
mediastinum. A direct tiny branch from brachiocephalic or subclavian
arteries to the mediastinum should also be considered.
The intercostal artery is important if a tumor invades the chest wall.
Careful attention to the spinal cord is essential to avoid spinal arterial
occlusion, especially when performing embolization of intercostal arteries in
the T8–L2 vertebral bodies segment.
The inferior phrenic artery sometimes penetrates the diaphragm and
feeds the inferior part of the mediastinum.
Although a thoracic aortogram is recommended to evaluate the
branching of the bronchial arteries,
13
a 3-D analysis of dynamic CT with
contrast is found to be more useful.
Most lung and mediastinal tumors, regardless of being primary or
metastatic tumors, are seen as area of hypervascularity and neovascularity.
Sometimes, the neoplastic lesion may show shunting of blood from the
bronchial artery branches into pulmonary artery or pulmonary vein.
14
Chest Wall Circulation
All branches from the subclavian artery, except for the vertebral artery, are
involved with recurrent lesions in the chest wall, axillary nodes, and
supraclavicular lymph node metastases. The intercostal arteries are potential
feeders for chest wall lesions. Almost all chest neoplastic lesions, including
lymph node metastases, are identified as hypervascular lesions compared to
normal tissue.
TECHNIQUE
There is no specific angiographic technique for embolization of intrathoracic
and chest wall malignancies. But compared to other organs, the diameter of
their arterial feeders is generally smaller. Infusion and embolization should
be done in state of free flow. For this reason, arterial spasm or intimal
damage caused by catheterization should be avoided. Operator experience,
careful manipulation of the arteries, and catheter insertion with a preshaped
microcatheter without microguidewire may help decrease the incidence of
complications. Other interventionalists prefer to carefully advance a
microcatheter with a microguidewire coaxially through a 4-Fr to 5-Fr
diagnostic catheter once the latter is in stable position at the aortic branch
ostium (e.g., intercostobronchial or bronchial arteries).
CT examination during selective angiography is reliable for recognizing
the anatomy of target arteries. Hybrid angiography suite–CT apparatus
provides angiographic and CT examinations in the same room and at the
same time, which helps our treatments from cost-effective standpoint. A
cone-beam CT function of recent angiography suites may be helpful, but the
diagnostic value is not good enough to evaluate tiny arterial supply.
Multidirectional digital subtraction angiography (DSA) may also be useful to
evaluate the arterial territory, but at the expenses of higher volume of contrast
material and radiation dose.
Antineoplastic agents should slowly be infused to the target artery,
avoiding backflow. A mixture with contrast material (1:1) is preferable to
recognize the flow. Immediately after completion of infusion, embolization
should be commenced. Embolic material should be mixed with contrast
material to get good opacity to check the free flow state. The end point of
embolization is not arterial occlusion but disappearance of tumor vasculature.
Flow reduction observed on fluoroscopy during the injection of embolic
material is a good sign that the embolization procedure is complete.
Bronchial artery embolization with drug infusion should be repeated
(two or three times) to obtain a better local response and to promote a longer
survival time.
1
CLINICAL APPLICATIONS
The main purpose of transarterial treatment for the lung and mediastinal
tumors is the reduction of tumor burden. Airway stenosis due to compression
or stenosis caused by tumor or direct invasion may cause serious symptoms.
The pulmonary hilum lymph node metastases or tumor invasion may result in
bronchial stenosis, which may consequently cause insufficiency of sputum
expectoration. It may evoke obstructive pneumonia or atelectasis (Fig. 20.1).
Irritation of bronchial mucosa causes severe cough or hemosputum. When the
tumors compress the trachea, patients complain of respiratory distress or
suffocation (Figs. 20.2 and 20.3). Mediastinal invasion or lymph node
metastases often cause compression of superior vena cava or pulmonary
arteries (see Fig. 20.2
). They are always life-limiting factors as bronchial
airway stenosis. Reduction of tumor burden by the embolization combined
with antineoplastic agents can be obtained as long as superselective
administration of drug and embolization can be performed.
Bleeding from the tumor is also serious problem. There are no effective
methods to get sufficient hemostasis from the tumor except for selective
arterial embolization. The bleeding point can easily be recognized as
extravasation or dense tumor vasculature on the DSA images (Fig. 20.4).
Immediately after the embolization of bleeding point, complete hemostasis
can be obtained.
In cases of local recurrence of breast cancer or chest wall invasion from
lung cancer cases, bone destruction including rib, sternum, and spine (Fig.
20.5) is a frequent problem. It usually causes uncontrollable pain.
Chemoembolizations can reduce pain probably due to control of excessive
blood flow to the hypervascularized lesion.
POTENTIAL COMPLICATIONS
The contraindications for bronchial or nonbronchial artery embolization are
the usual contraindications for angiography, including intractable
coagulopathy, renal failure, and severe contrast allergy. In addition, the
investigation of treatment history and allergic reactions to antineoplastic
agents are important to avoid anaphylactic shock during treatment.
The spinal cord circulation is an important factor. The branches to the
spinal cord from the bronchial artery are seldom found; however, a common
trunk with the intercostal artery is common, especially on the right side of the
chest (Fig. 20.6). Backflow of embolic material into the intercostal artery
should be carefully avoided. The branches from the costocervical artery and
thyrocervical artery are also important with regard to communication with the
vertebral artery. The mediastinal circulation is changing dynamically during
the embolization. The flow velocity and flow direction should carefully be
monitored under fluoroscopic observation.15 Very careful selective injection
into these mediastinal branches is critical.
Esophageal enhancement is sometimes visible in bronchial angiography.
There are no reported complications caused by arterial infusion or
embolization. We have also never experienced esophagitis or dysphagia after
these procedures. However, careful observation of esophageal circulation is
necessary.