Bronchial Artery Embolization as a Treatment of Hemoptysis Etiology, diagnosis, indications, technique, and results

Faculty of Medicine
Department of Radiology
Karvan Rasul Ismael
Etiology, diagnosis, indications, technique, and results
Final Master's Thesis
Kaunas, 2022
5. ABBREVIATIONS ................................................................................................................. 4
6. Terms ....................................................................................................................................... 5
7. INTRODUCTION ................................................................................................................... 6
8. BACKGROUND ..................................................................................................................... 7
9. LITERATURE REVIEW ........................................................................................................ 9
9.3 Pathophysiology and Causes of Haemoptysis ..................................................................... 13
9.4 Diagnosis of Haemoptysis ................................................................................................... 14
9.5 Diagnostic Imaging ............................................................................................................. 15
10. RESEARCH METHODS .................................................................................................. 17
10.1 Study Design ..................................................................................................................... 17
10.2 BAE Technique ................................................................................................................. 17
10.3 Bronchial Arteries ............................................................................................................. 20
12.2 Factors for Haemoptysis.................................................................................................... 28
12.3 Role of Surgery in the Management of Haemoptysis ....................................................... 30
12.4 Immediate Success Rate and Cumulative Nonrecurrence Rates ....................................... 31
13. CONCLUSIONS................................................................................................................ 34
Author: Karvan Rasul
Aim: To determine the effectiveness of the use of BAE in the treatment of haemoptysis and
provide the audience with the introduction of bronchial artery embolization and its practices in
the department of radiology. To compare and review the literature on modularity of BAE
haemoptysis, including aetiology, diagnosis, indications, technique, and more importantly final
results.
Objectives:
i. To determine the various techniques employed in the field of radiology in BAE
haemoptysis
ii. To determine the embolic materials used in BAE haemoptysis and its results.
iii. To determine the efficacy and safety of BAE in patients with acute major
haemoptysis
Methodology:
The study was a literature review where searches were conducted using some of the most
credible databases such as PubMed, and Cochrane. The keywords were matched to database
indexing terms. The literature chosen covers mainly the last 10 years and all the articles has been
assessed thoroughly. Applying eligible criteria using the keywords, “bronchial artery emboliza-
tion treatment” OR “bronchial artery embolization” OR “transcatheter embolization” OR
“diagnosis hemoptysis” was done to identify corresponding studies. Further study was a
retrospective analysis of the results of patients obtained at a tertiary care cardiothoracic hospital
coupled with a thorough assessment of secondary literature. The study entailed a thorough
retrospective view of all records, CT scans, and radiographs of patients with haemoptysis.
Results and Conclusions:
Based on the data obtained, a significant number of patients had co-morbidities in addition
to the underlying respiratory illnesses. The underlying diseases that, in one way or the other,
contributed to haemoptysis episodes were classified as pulmonary. The results of the study show
that various co-morbidities such as active pulmonary TB, previous pulmonary TB,
bronchiectasis, and carcinoma of the lungs accelerated the severity of haemoptysis. To
adequately control haemoptysis, BAE should be performed in the right manner followed by
follow-ups. The review concluded that the use of BAE is an effective procedure in addressing
both moderate and massive haemoptysis.
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2. ACKNOWLEGDEMENTS
I would like to express my special thanks of gratitude to my supervisor as well as the staff
at the radiology department. I am genuinely thankful to them. Secondly, I would also like to
thank my parents and friends who helped me to a great extent during this process.
3. CONFLICT OF INTERESTS
4. ETHICS COMMITTEE APPROVAL
No clearance issued by the ethics committee is required for this study. In full compliance
with ethical regulations and conduction codes.
5. ABBREVIATIONS
Some of the rare terms used in this study include;
Angiogenic growth factors – A group of molecules which exert a central in the process of
blood vessel formation.
Aspergilloma – A fungus ball (mycetoma) that develops in a preexisting cavity in the lung
parenchyma. The ball of fungus may move within the cavity but does not invade the cavity
wall. May initiate hemoptysis.
Carcinoma of lungs
Gelfoam slurry – Semi liquid mixture acting as a haemostatic and aid in the embolization
process.
Hypertrophied vessels
Iodized oil – A type of diagnostic imaging agent, administered by injection which
accumulates in the blood and lymph vessels, in tumors. Also called ethiodized oil, Ethiodol,
and Lipiod.
which, in presence of liquid polymerizes to form an adhesion.
Lung parenchyma
Mycetoma - A chronic, progressive local infection caused by fungi or bacteria.
Pseudoaneurysm- False aneurysms occurring at the site of arterial injury. Focal dilation of
an artery.
Thyrocervical arteries
Vasa vasorum - Supplies blood to the outer half of the aortic wall, lies within the adventitia.
These small vessels serve to provide blood supply and nourishment for tunica adventitia and
outer parts of tunica media of large vessels.
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Bronchial artery embolization (BAE) is considered an invasive alternative that is efficient
in the treatment of patients who have recurrent or massive haemoptysis. [1] The reason why
BAE is preferred is that it is not only an effective method but also a non-surgical one that does
not require one to be operated. The use of BAE requires embolic material such as polyvinyl
alcohol (PVA) particles as well as gelatin sponge particles. Recent research has shown that BAE
can also use newer embolic materials such as thrombin and tris-acryl gelatin microspheres,
which have shown successful outcomes. It was asserted by Fartoukh et al. [1] that every embolic
material has its unique characteristics and functions differently. Thus, every embolic material has
its advantages and disadvantages. However, there is no optimal embolic agent for BAE that has
been determined to date.
The use of N-butyl cyanoacrylate (NBCA) has been on the increase recently in the
treatment of BAE. It is a permanent liquid embolic material whose usage is accepted across the
globe. The embolic material has been used with great success. In the past, it was mainly used for
the embolization of cerebral arteriovenous malformation and had been gaining attention for the
control of bleeding from various peripheral vessels. [1] When used as an embolic agent, NBCA
has various merits compared to other embolic materials. Some of the merits associated with it is
that it can be effectively used among patients with coagulopathy, those with rapid, complete
vessel occlusion, and controlled embolization through the process of polymerization rate
adjustment. Besides, NBCA requires a short procedure time. Due to these merits, NBCA proves
to be a good embolic material for BAE.
Haemoptysis is considered one of the most dangerous respiratory emergencies and may
lead to death or other serious conditions if left unattended. [7] Without proper management,
haemoptysis may lead to the death of the patient. While there are many causes of haemoptysis,
some of the commonly known causes include fungal infections such as aspergilloma, non-
tubercular bronchiectasis, advanced interstitial pulmonary fibrosis, and cystic fibrosis. [2] Some
of the causes of haemoptysis that are less common include neoplasms, arterio-venous fistulae.
The tubercular lung disease is a cause common among some populations, such as the Indian
population.
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Selective catheterization of the bronchial arteries providing the affected areas followed
by embolizing agents has proven to be a productive treatment method for the control of bleeding.
With the introduction of modern microcatheters, robot-assisted ligation, and guidewires,
bronchial artery embolization has been safe and well forecasted by patients. [2]. Whereas this
treatment approach does not instantly influence the primary underlying disease, repetitive and
recurrent, elapses of bleeding are imminent and remain high. Thus, requiring further
embolization sessions. In patients who have undergone previous BAE, the major feeding arterial
supply mostly arises from non-bronchial systemic collateral vessels. BAE remains the mainstay
treatment due to its efficiency despite high relapse rates. The use of a new technique such as
robot-assisted ligation has emerged on the side-lines and continues to be used albeit keenly. The
study entails retrospective analysis of the results of patients obtained at a tertiary care cardio-
thoracic hospital. The study design was descriptive in nature, and it entailed a retrospective
analysis of cases that presented with haemoptysis at the centre. The study used records of
patients who underwent BAE from January 1, 2013, through May 30, 2016. The researcher
conducted a retrospective review of all the records, CT scans, and radiographs. The aim of this
study was to determine the effectiveness of the use of BAE in the treatment of haemoptysis.
8. BACKGROUND
In a study by, Mondoni [2] about 5-14 per cent of the patients who have haemoptysis
might have life-threatening haemoptysis. Such a kind of haemoptysis is also known as massive
haemoptysis and is determined by the volume of blood that is lost per hour measured over a 24-
hour period. Besides, it can be determined by the presence of abnormal gas exchange or
hemodynamic instability. Any bleeding rate that is higher than 100 mL/h is considered massive
haemoptysis. [2] However, the amount of blood loss may also be studied alongside the patient’s
underlying conditions. For instance, in patients with underlying conditions such as
cardiopulmonary status, smaller volumes of haemoptysis may be considered life-threatening. For
such patients, a bleeding rate of 50 mL and below may still be considered life-threatening. As
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such, physicians are advised not to generalize cases of haemoptysis but consider each of the
cases separately based on the status of the patient.
The recorded mortality rate arising from massive haemoptysis is around nine and thirty-
eight per cent. There are various factors that may determine a poor outcome, especially in
patients experiencing massive haemoptysis. Some of these commonly known factors include
aspiration of blood into the contralateral lung, rapid bleeding rate amounting to the loss of blood
amounting to more than 100 mL within a period of 24 hours, and life-threatening bleeding that
necessitates the use of single-lung ventilation. [3] Some other risk factors include patients
requiring mechanical ventilation, patients with cancer, those with chronic alcoholism, or where
haemoptysis involved the pulmonary artery. When such factors and conditions are identified, the
physicians need to be keen enough to ensure that the patients are properly stabilized to avoid
severe cases or deterioration of their health.
8.1 Aim and Objectives
The aim of this study is to determine the effectiveness of the use of BAE in the treatment
of haemoptysis. Furthermore, this research is also intended to provide the audience with the
introduction of bronchial artery embolization and its practices in the department of radiology.
The objective of this research is to investigate various techniques and embolic materials
employed in the field of radiology dealing with BA haemoptysis. The work is designed using
both quantitative and qualitative approaches to elicit information on the final results of BAE due
to the nature of the data used. By analysing different literature, and recently developed
embolization techniques, researchers not only review outcome rates but also engage for a
satisfactory result.
Although it is crucial with a clinician set of skills, continuous developing methods may
benefit the medical community in implementing and providing these ideas in their practices.
While a definitive success rate is not always apparent, we can perhaps present results as near it
can get. Following the above elaboration, the objectives of the researcher are;
v. To determine the various techniques employed in the field of radiology in BAE
haemoptysis
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vi. To determine the embolic materials used in BAE haemoptysis
vii. To determine the efficacy and safety of BAE in patients with acute major
haemoptysis
9. LITERATURE REVIEW
9.1 Choice of Embolizing Agent
The choice of the embolizing agent is determined by several factors. Larici et al. [3]
found that aspects such as the durability of the agent, the size, risk of recanalization, and
effortlessness of delivery are essential to consider when choosing the embolizing agent. Khalil et
al. [4] disclosed that polyvinyl alcohol (PVA) is one of the commonly used embolization agents
across the globe. The reason for its wide acceptability is its non-absorbability properties which
make it a better option for enhancing permanent occlusion. Compared to a gelatin sponge that is
known to give a temporary, proximal embolization, PVA is rather permanent. The gelatin sponge
is not preferred as it increases the risk of recanalization. The common PVA particle sizes which
are recommended for use in BAE should be in the range of 300-500µm. [3]
When smaller sizes are used in BAE, it can lead to pulmonary infarction as well as
bronchial necrosis. Usually, this happens due to infiltration through the bronchopulmonary
anastomoses. Despite this, Hankerson et al. [5] added that PVA particles might aggregate within
microcatheters, which may lead to unwanted proximal occlusion. Due to their spherical and
uniform shape, microspheres have a lower risk of clumping and have been used successfully,
showing positive outcomes in clinical usages.
On the other hand, a study by Fartoukh et al. [1] showed that liquid embolizing agents
such as NBCA are usually efficient when used for the control of haemoptysis in cases of
bronchiectasis. To operate these, skilled interventional radiologists are required to avoid an
increase in complications. Accordingly, Komura et al. [6] acknowledged the increased usage of
metallic micro coils in clinical treatments to control haemoptysis in BAE. However, the usage of
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metallic micro coils has not been frequently used in recent times. When used, the metallic micro
coils achieve proximal embolization, which limits the chances for further interventions in case of
recurrence of haemoptysis. Micro coil is now mainly being used by clinicians when treating
pseudoaneurysms, arteriovenous malformations, and NBSAs. [7]
9.2 Bronchial Artery Embolization Procedures
According to Larici et al. [3], BAE is a procedure that uses X-rays to examine the
bronchial arteries. By conducting BAE, it allows the doctor to find the bronchial artery that is
bleeding, and that may have caused haemoptysis or coughing up of blood. Bellam et al. [7] stated
that blood vessels such as arteries and veins are not revealed in a normal chest X-ray. For the
blood vessels to be identified, a special dye is injected into the artery. This is done via the groin
and is done by the use of a fine plastic tube known as a catheter. Once this is done, X-rays are
then taken immediately afterward. The process makes it possible to see detailed images of the
veins and arteries in the lungs. One of the ways and approaches for stopping the identified
bleeding is by inserting tiny particles to clot the vessel. [1]
The purpose of the BAE procedure is to stop the flow of blood from the bleeding vessel
while at the same time allowing blood flow in the surrounding area. The bronchial arteries are
the ones responsible for the provision of blood to the lungs. In the treatment procedures, the
interventional radiologist will choose to use either resin particles or small metal spirals into the
bleeding area to stop the bleed. When this is done, the blood is prevented from entering the
vessels resulting in the stoppage of the bleeding.
Figure 1
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In figure 1 above, (a) shows a CT scan of a patient who had recurrent hemoptysis. The image
shows bronchiectasis as well as fibrotic changes. (b) shows what was obtained after a DSA was
done before BAE. The figure shows hypertrophied Rt Intercostobronchial trunk with significant
abnormal vascular blush. (c) shows the complete disappearance of abnormal vascular blush.
A review done by Larici et al. [3] elaborated that most of the commonly embolized
arteries are mainly the lateral thoracic artery, intercostal arteries, bronchial arteries, and the
branches from the thyrocervical and costocervical trunk. Khalil et al. [4] investigated that PVA
particles are some of the materials that can be used as embolizing materials. In some cases,
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pushable fibered metal coils and gel foam slurry is used. It is also common to inject smaller
particles that are then followed by larger particles, although this is determined by the extent of
the bleeding.
Komura et al. [6] opined that once BAE is performed, a follow-up exercise is conducted
on the patient to identify any cases of recurrent haemoptysis as well as any other complications.
Once patients are confirmed to be out of danger, they can be discharged and observed on an
outpatient basis. The necessity for some patients to undergo bronchoscopy is common some
weeks after BAE. Patients may also undergo contrast-enhanced CT every 4-5 months to get an
assessment on possible procedure-related complications as well as evaluation for any underlying
disease. [3]
A further study by Mondoni [2] concluded that haemoptysis is a serious life-threatening
respiratory emergency that shows potentially serious underlying intrathoracic disease. When
haemoptysis is in larger volumes is poses greater mortality and requires urgent investigation and
intervention. Upon further evaluation, Khalil et al. [4] accentuated that initial assessment by
chest radiography, computed tomography (CT), and bronchoscopy is essential in treating the
bleeding site as well as in the identification of the underlying cause. One of the new technologies
that has increased usage today is multidetector CT angiography which allows delineation of
abnormal nonbronchial and bronchial arteries through the use of reformatted images in several
projections. These can be effectively used in guiding therapeutic arterial embolization
procedures.
Komura et al. [6] emphasized the increased usage of BAE in clinical settings is a result of
its effectiveness, especially in the management of both recurrent and massive haemoptysis. It can
be applied as an adjunct to elective surgery or as first-line therapy. With an experienced operator,
BAE is a safe technique to address the challenges of the bronchial arteries. Bellam et al. [7]
added that prompt repeat embolization is necessary, especially for patients experiencing
recurrent haemoptysis. The repeat embolization helps in the identification of nonbronchial
systemic as well as pulmonary arterial sources of bleeding.
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9.3 Pathophysiology and Causes of Haemoptysis
The flow of the blood in the lungs is a system that entails the bronchial arterial system
and the pulmonary system. Komura et al. [6] reported that the pulmonary arteries provide more
than 99% of the blood in the lungs and are also key in the gaseous exchange process. The
remaining 1% is usually comprised of the bronchial arteries, and they supply nutrient branches to
veins, the bronchi, and smaller bronchopulmonary branches to the lung parenchyma. Larici et al.
[3] clubbed and opined that both the pulmonary and bronchial systems are connected by several
anastomoses. This connection helps the two systems to communicate, making them produce
physiological right-to-left shunts, which contribute to the total cardiac output.
There are some instances such as hypoxic vasoconstriction that are revelations of a
compromised pulmonary circulation which are manifested through the proliferation and
enlargement of bronchial arteries, which end up replacing the pulmonary circulation. Some
similar other conditions include vasculitis and intravascular thrombosis. Furthermore, Mondoni
[2] recognized that there also exist other reasons that are associated with the enlargement of the
bronchial arteries, such as the chronic inflammation of the lungs. The chronic inflammation of
the lungs arises due to abnormal enhanced communication with the pulmonary arterioles.
Additionally, Mondoni [2] mentioned that the release of angiogenic growth factors may
be a result of inflammatory processes and may lead to recruitment of collateral supply from close
systemic vessels and neovascularization. The adjacent systemic vessels are fragile due to their
thin walls and are prone to rupture, especially when exposed to higher systemic arterial
pressures. When they rapture, they result in haemoptysis.
Hankerson et al. [5] compared that the difference between different types of haemoptysis
is in the flow of blood witnessed. For instance, massive haemoptysis is said to be any type of
haemoptysis that is characterized by a blood flow of 300-600 ml of blood within 24 hours. [2]
Bellam et al. [7] opined that blood of any amount from 400 ml in the alveolar space might
adversely affect gaseous exchange. In such a case, the cause of death is mainly asphyxiation as
opposed to exsanguination.
9.4 Diagnosis of Haemoptysis
The first thing to be considered in the evaluation of patients with or suspected to have
haemoptysis is to determine the source of bleeding and also identify the major cause. Some of
the tests that can be conducted during the initial evaluation process include chest radiography,
bronchoscopy, chest computed tomography (CT), and sputum examination. The sputum is tested
so as to determine whether…