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Файл:Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3733_Библиотеки_им_академика_М_И_Перельмана.pdf
BRONCHIAL ANATOMY
Bronchial arteries provide oxygen and nutritional elements to different
pulmonary structures and also some adjacent mediastinal structures. They
supply the trachea, bronchi, visceral pleura, and esophagus and the vasa
vasorum of the aorta, pulmonary artery, and vein.
24
Although there are many variations, there are usually two bronchial
arteries that run in the right lung and one in the left lung. Bronchial arteries
originally measure about 1 to 1.5 mm diameter. Above this diameter, they
must be considered pathologic.25 The most common source of hemoptysis is
located in the bronchial arteries (90%), and only in 5% of cases the
pulmonary circulation is the origin of the bleeding.
26
The remaining 5% of pulmonary bleeding originates directly from the
aorta or systemic intrathoracic or extrathoracic branches.
27–29
In over 70% of
the general population, the bronchial arteries arise directly from the
descending thoracic aorta, most commonly between the levels of T5 and
T6.30 When the bronchial arteries arise at these levels, they are called
orthotopic, and when the source is outside these levels, their name is ectopic
(8% to 35%). These ectopic bronchial arteries may originate from the aortic
arch, brachiocephalic artery, subclavian artery, internal mammary artery,
thyrocervical trunk, coronary arteries, costocervical trunk,
pericardiacophrenic artery, inferior phrenic artery, or abdominal aorta31 (Fig.
18.1).
According to the classification of Morita et al.,32 the main right
bronchial artery arises from the intercostobronchial trunk in more than 50%
of the cases, and in the rest, it comes from a common trunk (right and left
bronchial arteries) from the subclavian artery or directly from the aorta. Left
bronchial artery, on the other hand, arises from a bronchial common trunk
(right-left) in over 95% of the cases. Referencing the axial division of the
aorta into eight segments, the right intercostobronchial artery ostium is
usually located in the medial segment or anteromedial, whereas the origin of
the bronchial common trunk (right-left) arises from the anterolateral segment
(>70%)33 (Fig. 18.2).
Cauldwell et al.34 reported four classic bronchial artery branching
patterns: type I, one intercostobronchial trunk on the right and two bronchial
arteries on the left (40%); type II, one intercostobronchial trunk on the right
and one on the left (21%); type III, two branches on the right (one
intercostobronchial trunk and one bronchial artery) and two bronchial arteries
on the left (20%); and type IV, two on the right (one intercostobronchial
trunk and one bronchial artery) and one bronchial artery on the left (9.7%)
(Fig. 18.3).
The right intercostobronchial trunk is the most consistently seen vessel
at angiography (80% of individuals) (Fig. 18.4). It usually arises from the
right posterolateral aspect of the thoracic aorta, whereas the normal right and
left bronchial arteries arise from the anterolateral aspect of the aorta. Right
and left bronchial arteries that arise from the aorta as a common trunk are not
uncommon at angiography (Fig. 18.5). The true prevalence of a common
bronchial artery trunk is unknown.
Of particular relevance is the anatomy of the nearby spinal arteries.
During bronchial angiography, we can observe two types of spinal arteries
that must always be avoided: the dorsal and ventral radicular arteries, which
supply the dorsal and ventral nerve root and which emerge from the
intercostal arteries, and the anterior medullary arteries. An average of eight
arteries supply the spinal cord from its anterior side. In 5% to 10% of cases,
they can be observed during bronchial angiography, usually arising from the
intercostal artery of the right intercostobronchial trunk. Adamkiewicz artery
or great anterior radiculomedullary artery is the most important artery in
terms of medullary irrigation. This artery arises from the left side of the aorta,
from T9 to L1, in 75% of cases. Anterior medullary arteries have a
characteristic “hairpin” configuration at angiography35 (Fig. 18.6).
Often, spinal arteries cannot be observed initially in the angiography.
They only become visible when the distal vessels are embolized, as recalled
by Brown and Ray36 (Fig. 18.7).
WORKUP
Initial priorities are ensuring adequate airway protection, ventilation, and
cardiovascular function. Patients with poor gas exchange, rapid ongoing
hemoptysis, hemodynamic instability, or severe shortness of breath should be
orally intubated with a large-bore endotracheal tube (size 8.0 or greater).
15,17
Coagulation disorders should be rapidly reversed.
If the location or site of bleeding is known, placing the bleeding lung in
a dependent position may prevent blood spillage into the nonbleeding lung.
An alternative strategy involves placement of a typical, single lumen
endotracheal tube into either the right or the left mainstem bronchus. The
approach of selective intubation is less practical when the right lung is
bleeding because selective intubation of the left mainstem bronchus may be
difficult. A third alternative is the placement of a double lumen endotracheal
tube specially designed for selective intubation of the right or left mainstem
bronchi.
21,37
The evaluation should begin with the initial history and physical
examination supplemented by chest radiograph. Important features of the
history include age, smoking history, duration of hemoptysis, and association
with symptoms of acute bronchitis or an acute exacerbation of chronic
bronchitis.
21
Vital signs including pulse oximetry levels and blood gases,
temperature, heart rate, and breathing should be recorded and fever,
tachycardia, tachypnea, and hypoxia corrected.
In a survey of respiratory physicians during the 1998 American College
of Chest Physicians (ACCP) Annual International Scientific Assembly, more
than 50% of these clinicians favored the use of interventional angiography
even in surgical patients, which was a substantial change from 1988 when
only 23% had favored this approach.
1
Location of Bleeding: Computed Tomography versus
Bronchoscopy
Diagnostic examination in massive hemoptysis should focus on etiology and
identification of the site of bleeding. Such examination commonly involves
chest radiography, fiberoptic bronchoscopy, and chest CT.
38
Despite the fact that chest radiography is a standard procedure and is
always available, it rarely provides clear information on the site of bleeding.
Various studies have reported that fiberoptic bronchoscopy can help to
locate the site of the hemorrhage in between 49% and 92.9% of cases.
21,23
Fiberoptic bronchoscopy is often considered in patients with hemoptysis and
a normal or nonlocalizing chest X-ray to rule out endobronchial malignancy.
Performed early in the evaluation, while the patient is actively bleeding,
provides the highest performance for locating the bleeding site.
1
Many experts advocate the use of fiberoptic bronchoscopy as the
primary method of localizing the site of bleeding in massive hemoptysis,
39,40
but many studies have downplayed this technique and even set it aside just as
an aid to the location of the bleeding before arterial embolization.
41
Instead, an early chest CT has been advocated to help localize the
bleeding site and diagnose the cause of hemoptysis.42 The advantage of CT is
that it may define one of several diagnoses such as bronchiectasis, lung
abscess, and mass lesions, including cancer, mycetomas, and arteriovenous
malformations. CT can localize the site of bleeding in 63% to 100% of cases.
Specifically, CT can aid in diagnosing nonbronchial systemic supply in 80%
of cases, with the lowest success in visualizing internal mammary supply.
43
Knowledge of nonbronchial supply in advance has the potential for
increasing the success rate of initial embolization.
21,41
It may also help in
acute cases to guide arteriography or bronchoscopy to the regions of highest
yield.
Revel and coworkers38 wondered if CT could replace bronchoscopy in
the detection of the site and cause of bleeding in patients with large or
massive hemoptysis. The disadvantage of chest CT is that it may require
temporary movement of an unstable patient away from intensive care.
Nowadays with the availability of multislice CT, the use of the
fibrobronchoscopy and the arteriography has been questioned for the location
and diagnosis of the bleeding. Undoubtedly, the quality of the images, their
precision, and the speed and readiness cause CT to play an important role in
the diagnosis of the hemoptysis. It has several potential interests, including
anatomic workup of bronchial and systemic arterial anatomy to the lung and
diagnosis of uncommon sources of bleeding such as pulmonary artery
43,44
(Fig. 18.8).
Bronchial and Systemic Angiography
The main objective of a severe hemoptysis diagnosis is the design of an
appropriate treatment approach. It is unquestionable that embolization stands
out as the optimal treatment. Every embolization requires a previous
angiographic study, which is the gold standard for diagnosis of hemoptysis.
However, although CT might delay the intervention, it may be very helpful to
understand the etiology, the mechanism of bleeding, and the origin of
aberrant bronchial or systemic arteries and to plan a successful procedure.
45
If the patient continues bleeding and the source is still unknown, then
arteriography should be performed next because it may be useful for therapy
as well as for diagnosis. Because most massive bleedings arise from the
bronchial circulation, bronchial arteriography has a higher performance than
arteriography of the pulmonary or systemic arterial beds.
Knowledge of the anatomy of the bronchial arteries is crucial for their
location and examination. The bronchial arteries exhibit several anatomic
variations in terms of both their origin and their various branches.
32,34
When the pulmonary arterial circulation is the source, the most common
underlying conditions are pulmonary arteriovenous malformations,
Rasmussen aneurysms, or iatrogenic pulmonary artery tears. A recent study
observed that 8 (10.5%) in a series of 76 patients undergoing bronchial
angiography for hemoptysis had visible pulmonary artery
pseudoaneurysms.46 In our series,23 the pulmonary artery was the origin of
pulmonary bleeding in 6 patients (2%) with different causes. In only one case
a Rasmussen aneurysm was diagnosed (Fig. 18.9).
Occasionally, other systemic arteries of the chest or in the vicinity are