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470 oracic ultrasound
• Always confirm the outcome of the procedure by ultrasound.
• Search ultrasound detectable complications.
Lung and mediastinal biopsy
Many concepts already discussed are applied for performing intra-thoracic biopsies.
Percutaneous needle biopsy (PNB) is defined as placement of a needle into a suspected
abnormal lesion or organ for obtaining tissue or cells for diagnosis. Two basic techniques
for sample acquisition are employed: fine needle aspiration biopsy (FNAB) and core biopsy
(CB). e first uses a thin, hollow needle (21 G or smaller) inserted into a region of interest to aspirate cells (cytological evaluation). e second uses a hollow needle adapted with a
cutting mechanism (cutting needles and automatic core biopsy needles, 20 G or larger) able
to extract a piece of tissue for hystological evaluation (Fig. 37) (Tab. 12).
FNAB and CB are complementary techniques. e yield of FNAB alone is high in lung
carcinoma, while CB is necessary in all other malignant tumours and in benign diseases.
In many cases, ultrasound is the imaging method of choice for performing biopsies. Generally
speaking, when a target is sonographically detectable, the ultrasound guide is the first option.
Table 12 - Needles for biopsy
Needle Description
Aspiration needle
• Chiba needle
Cutting needle
• Franseen needle
• Westcott needle
Automated core biopsy needle
• Temno® needle
• Achieve® needle
• Biomol® needle
Chiba needle has a 30° bevel, and is available in 18 to 25
gauge sizes. It Is useful for making diagnosis of epithelial
carcinomas (adenocarcinoma and squamous cell carcinoma),
because their diagnosis can be made on cytological analysis
alone. It is the less traumatic needle, but it is flexible and can
bend or deflect off course.
These needle have variegated tip or a cutting notch on the
side (Trucut). Typical size used are 18 to 22 G. They act as
modified aspiration needles, in that they cut tissue in addition
to aspirating it.
Temno® and Achieve® needles are used to obtain tissue for
hystologic evaluation. They are double-throw devices that
use a spring activated mechanism to sequentially fire first a
thin notched needle, followed by an outer cannula. Biomol®
needle uses a vacuum device to provide suction to aid tissue
sampling.
Ultrasound (US) can visualize solid lesions arising from the pleura, chest wall and, some-
provided they extend to the pleura. erefore, ultrasound can frequently replace computed
tomographic guidance at much lower cost. US assisted biopsy integrated easily with routine
practice, as it only requires basic ultrasound equipment and consumables commonly used by
chest physicians for diagnostic thoracentesis or lymph node aspiration.
During the procedure the patient must maintain the same position, but certain patients have
difficulty breathing in the prone position. e administration of pain medications and local
Interventional chest ultrasound 471
anesthesia is desirable. Sometimes a conscious sedation is necessary. In every case, the patient
must be alert enough to follow breath hold instructions.
e pain associated with TTNB is usually limited, and is mainly related to the violation of
the parietal pleura with the needle.
After the target is clearly reproduced on the screen, the biopsy needle is introduced through
the dermatotomy into the subcutaneous tissue. ese procedures, and the probe-needle
coupling, are done according to the principles previously described. All needle movements
should be performed with the patient’s respiration suspended. e needle is introduced to
the level of the serosal layers and it is advanced in one motion through the pleura, under
ultrasound control, into the target. When the needle is inside the lesion, the patient may
breathe quietly, and the needle should be allowed to move with respiratory motion, to avoid
a lacerating effect on the pleura.
After assessing the position of the needle inside the target, a tissue sample may be obtained
firing the device’s aspirating or cutting systems, while the patient suspends the respiration. If
a Chiba or Biomol® needle is used, the device is moved to and from and rotated within the
lesion for 5-7 seconds, while continuous suction is applied. If an automated tru-cut needle
(Temno®, Achieve®) is used, the inner side notch needle fires first, followed rapidly by the
outer cutting cannula. In this case, the device tip must be documented before the needle is
fired, because the inner side-notch needle suddenly elongates during the biopsy and its path
must be known.
In our experience, 18-20 G Biomoll® needle is the first choice device for echoguided pulmonary biopsies. 18-14 G Temno® needle is preferred for parietal and pleural interventions.
Complications of TTNB include pneumothorax, hemothorax, hemoptysis, infection and
air embolism.
Increased age of the patient, obstructive lung diseases, deep lesions, multiple passes, long time
of execution and trasversal of fissure increase the risk of pneumothorax.
Pneumothorax is an early complication, and ultrasound can easily detect it when the lesion
suddenly disappears. e incidence of pneumothorax is essentially the same for FNAB and
core biopsy using automated biopsy devices.
When a pneumothorax develops, the patient is placed upside down and oxygen should be
administered. Hypertensive PNX must be treated by emergent percutaneous needle decompression. When the PNX is moderate in size and the patient is symptomatic, a chest tube or
catheter is often needed. Whit the biopsy needle within the thorax, simple aspiration of the
air collection may be performed. Many time a conservative treatment is appropriate.
Ultrasound allows to assess PNX extension and resolution according to the criteria already
discussed. An unchanged PNX at 4 hours post biopsy is unlikely to enlarge.
Incidence of parenchimal hemorrhages is around 10%. ey usually require no intervention.
Hemopthysis complicates 7% of the procedures and is almost always self-limited.
Finally, air embolism is extremely rare.
Mediastinal lesions may be biopsied under ultrasound guidance if they are sonographically
visible. In these cases, the risk of pneumothorax is low because the lung parenchima is not
crossed. In the case of an anterior access, care should be taken to locate the internal mammary vessels. Pleural and parietal lesions may be biopsied using any needle type, however we
prefer a 18-14 G Tru-cut device. Using an echoguided approach, the risk of pneumothorax
is negligible.
472 oracic ultrasound
Recently, several investigators reported the initial application of contrast enhanced ultrasonography (LCEUS) for diagnosis of peripheral lung lesions. LCEUS allows the clinician
to differentiate vital from necrotic tissue with great confidence. erefore, the enhancement
pattern, evaluated by contrast enhanced sonography, can identify viable tissue for focused
needle biopsy, improving its diagnostic efficacy.
Pleural biopsy
Pleural fluid citology is able to diagnose, at best, up to 60% of malignant effusions. Investigative
options for citology-negative effusions include surgical and medical video assisted thoracoscopy (VATS) and blind or image-guided needle pleural biopsy. e diagnostic yield for blind
needle biopsies ranges 27-57%. Imaging guided pleural biopsy can improve the success rate,
with ultrasound guidance producing a yeld of 87%.
Figure 38 – Pleural biopsy by Tru Cut needle.
e aim of ultrasound guidance is two-fold. First, pleural thickenings, ondulations, nodules
and massess may be identified. Secondly, the use of Doppler mode allows to identify a safe
and vital (non necrotic) area from which the biopsy may be taken.
Cope’s and Abrams’ needles biopsy were developed many years ago and used blindly by generations of chest physicians. In particular, the Abrams’ needle requires the use of both hands
and therefore it is not convenient for performing echo-guided biopsies. For this reason we
use Trucut needles (Temno®) that can be manipulated with the dominant hand, leaving the
other hand free for moving the probe.
Interventional chest ultrasound 473
After the skin has been cleaned with iodo-povidone solution, 1% xylocaine is used to anesthetize the skin and subcutaneous tissue down to the parietal pleura, using a 25 G spinal
needle. A 2 mm incision through skin is made. e trucut needle (16-18 G) is then introduced in plane with the probe, under continuous ultrasound guidance, at 30-40° to the skin
in the direction of the chosen intercostal space above the lower rib. Ultrasound inspection
and a definite “give” indicate entry into the pleural effusion and is confirmed by the ease of
advancement of the inner stilet. e Tru-cut needle as a whole is angled towards the skin,
allowing the cutting edge of the inner stilet to be advanced along the inner aspect of the chest
and away from the lung. Finally, the outer cutting sheath is advanced over the stilet, resulting
in biopsy of up to 2 cm of parietal pleura (Fig. 38).
Pericardiocentesis
Pericardiocentesis has been practiced for decades (since the eighteenth century) with blind
method and with high rates of complications70. Echocardiography has stimulated the devel-
opment of echo-guided puncture procedures. erefore, the considerations on the drainage
of pleural effusions also apply to effusions located in the pericardial sac.
e most frequent etiologies of pericardial effusion requiring drainage are heart surgery, cancer
and tuberculosis. Often the need for drainage may take place in emergency, when the fluid
determines cardiac tamponade71.
e blind puncture of the pericardium employs only anatomical landmarks. e needle (for
example the 18 G uohy needle) is introduced below the ensiform apophysis of the sternum,
with an inclination of 45 degrees, and directed toward the left shoulder. is extrapleural way
tends to avoid coronary, pericardial and mammary arteries. However, it may pass through
the left lobe of the liver and always pierces the diaphragm. It is not possible to observe the
underlying structures that are missed or hit.
e contact with the heart may be signaled by a lesional wave on the ECG lead applied to
the needle, when it touches the epicardium, but this complicates the procedure.
rough the needle it is possible to reach the pericardium with a soft J-shaped guide wire,
and, after dilation, a 5-8 Fr pigtail catheter may be inserted.
During blind punctures the greatest risks are:
• Hemorrhage along the needle tract (liver, diaphragm)
• Pneumothorax
• Hemopericardium
• Myocardial laceration
• Coronary vessel injury.
Other complications include arrhythmias (especially bradycardia from vasovagal reflex),
hemoperitoneum, gaseous embolism and injuries of the internal mammary vessels.
In the past, pericardial procedures were performed under fluoroscopic control, identifying the
position of the needle with a few drops of contrast injected through at least two angiographic
projections. Of course, this technique is complex and long. Moreover, it exposes to ionizing
radiation and is not appropriate to emergency situations.
Under ultrasound guidance, with real-time display of the effusion and its relationship with
the cardiac walls and cavities, the definition of cutaneous findings is useless.
Ultrasound-guided anesthesia is performed in a similar way to the puncture of the pleural
cavity72. e needle may be introduced with extreme precision in the pericardium, searching
474 oracic ultrasound
the site where the liquid is most abundant or where the access is more simple (through fewer
tissues and away from important structures). A practical and safe access is in the fourth or
fifth left intercostal space, along a parasternal line outside of the internal mammary vessels
(about 3-4 cm to the left side of the sternum). ese vessels are constantly seen in echography, and in doubtful cases their display is facilitated by using color Doppler. e most
frequently used access is the region around the areola (at the apex cordis), as there is more
liquid because of gravity.
If the fluid thickness is greater than 1-1.5 cm, the procedure is safe if the images are acquired
by a linear probe. e coupling needle/probe may be in plane or out of plane. A lung puncture is easily avoided by studying the movements of the pulmonary curtain on heart. e
ultrasound-guided pericardiocentesis reduces the possibility of complications and can be
performed at the bedside.
e image of the tip of the needle is very specific but, if doubts emerge, the introduction of
a few drops of liquid through the syringe creates a contrast effect in pericardial fluid (microbubbles). Finally, the Seldinger technique allows an easy placement of a drainage catheter.
When the anterior pericardial collection is more than 10 mm thick, an ultrasound guided
drainage is carried out successfully in 93-97% of cases. However, small rear effusions may be
missed in more than 60% of cases.
Studies on large series of patients undergoing ultrasound-guided pericardial puncture indicate
an incidence of complications between 1.2% and 3.5%73. Clip 7 illustrates the procedure in
a patient with cardiac tamponade.
Clip 7 – Echoguided pericardiocentesis in a patient with clinical signs of
cardiac tamponade.
➣ Evaluation of the pacemaker capture
During transcutaneous and transvenous cardiac pacing, the capture of the heart by the pacemaker may be assessed with difficulty. e sonographic visualization of ventricular contraction,
synchronous with the pacemaker spike, indicates the success of the catch74.
Ultrasound allows to view the arrival of the catheter in the right atrium and its transit into
the right ventricle. Sonogrphy can highlight the catheter pacemaker in the cardiac cavity, and
check directly the ventricular stimulation (Clips 8-10).
e transvenous placement may be performed under ultrasound guidance at the bedside
(Clip 11).
Clips 8, 9, 10 – Evidence of the catheter tip in the right atrium (Clip 8),
advancing at level of the tricuspid annulus (Clip 9) and its placement in the
right ventricle with the demonstration of the effectiveness of stimulation that
can be deduced from the increase in heart rate (Clip 10).
Interventional chest ultrasound 475
Clip 11 – Procedure for echo-guided placement of temporary pacemaker
via the right internal jugular vein.
➣ Echo-guided recruitment of consolidations
As already discussed, the critically ill patient frequently shows pulmonary hyperdensities of
variable degrees, up to consolidations. ese hyperdensities are characterized by an uneven
pulmonary arrangement, although the gravitational expression of the most important densities is characteristic.
e main problem during the re-expansion of the consolidations is related to hyperexpansion
of the better ventilated regions, which are exposed to volumetric and barometric ventilatory
trauma75.
Recruitment is a strategy suitable for the re-expansion of collapsed lung tissue and, subsequently, to generate pressures (Positive End Expiratory Pressure - PEEP) that prevent a
derecruitment.
To recruit pathological lung regions it is necessary to provide enough pressure to overcome
the critical opening pressure of the collapsed lung. In the dependent lung regions this pressure may exceed 50 cm H2O, well in excess of that required to keep the airway open in non
dependent regions.
A strategy that ideally allows to ventilate the hyperdense regions of the lung, without hyperstretching the healthy regions, is the basis for many ventilatory techniques and for a favorable
positioning of the patient.
A recruitment is conducted by increasing (about 40 cm H2O) the airway pressure (PEEP)
for a period (40-90 seconds) suitable to expand the hypoexpanded or consolidated areas of
the lung. ereafter a PEEP is produced (10-15 cm H
is clear that monitoring this procedure with traditional methods (X-ray, blood gases, curves
P/V) shows a relative inertia and may be inaccurate.
Despite its accuracy in quantitative terms (densitometry according to the Hounsfield units)76,
CT is not a practical technique, because it requires the patient transfer and exposes to a
significant radiant load.
Despite a great theoretical interest, literature data relating to ultrasound-guided recruitment
are scarce. Its rationale can be summarized in few points. First, ultrasound is easily performed
at the bedside without ionizing radiations. Above all, ultrasonography is highly predictive
for detecting the preconsolidating (B Lines in their various concentrations, white lung), and
consolidating (more or less aerated consolidations) hyperdense range of the subpleural plane.
Assuming the pleural mirror as a normal pattern (A lines), the increasing concentration of B
Lines may be interpreted as a more or less preconsolidating derecruitment, up to the white
lung. Fully consolidated lung represents the overcoming of the density threshold confirmed by
the presence of a real acoustic window. In practical terms an effective recruitment maneuver
should then produce in the first case a rarefaction of B Lines and, in the second case, the
transformation of a consolidation (and therefore a real image of tissue) in an artifactual field.
ese issues have recently been confirmed in a work of Bouhemad and coworkers77 in which
a significant correlation was found between recruitment, induced by increases in PEEP in
O) stabilizing the results obtained. It
2
476 oracic ultrasound
patients with ARDS, and a score of re-aeration of the lung based on the reduction of B- Lines
concentration on the disappearance of consolidations. is bedside method for recruitment
evaluation opens important monitoring scenarios for critical patients. e main drawback
of ultrasound in the evaluation of recruitment is the failure of sonography for estimating
lung hyperdistensions in vulnerable areas. Indeed, currently no method for distinguishing a
normal specular lung from an hyperdistended specular lung does not exist.
At Meyer Children’s Hospital in Florence (Pediatric Intensive Care, F. Melosi, G. Soldati, G.
Fognani, L. Mirabile, unpublished data) recruitment maneuvers were directed exclusively
to consolidations. Under continuous ultrasound monitoring, the inspiratory pressure was
increased to 40 cmH2O for 40-60 seconds for a maximum of three times. e re-expansion
of the consolidated tissue was announced by the increase in volume of the collapsed tissue
and the appearance of an echographic interstitial syndrome. Subsequently, an opening of the
consolidated airways was ensured with a PEEP of 10-17 cm H2O.
Although the expansion of the hyperdense regions (showing white lung and B Lines) is
signaled by the appearance of a pleural mirror or hypermirror (A Lines), this was not con-
sidered a goal, and was avoided. When tolerated, a “permissive white”, i.e. the persistence
of ultrasound artifactual components, can reduce the risk of overdistension and barotrauma
(Clips 12-16, 17-22).
Clips 12, 13, 14, 15, 16 – Area of alveolar collapse in patient with ARDS
undergoing mechanical ventilation. Clip 12 documents the consolidation and
dynamic air bronchograms. The increments of PEEP (10 to 22 cm H2O) only
involves the recruitment of dead space, documented by the increase in air
bronchograms without obtaining alveolar recruitment. PEEP greater than
22 cm H2O do not cause changes. In this patient, the consolidation was
therefore not recruitable.
Clips 17, 18, 19, 20, 21, 22 – Alveolar collapse in patient with ARDS
undergoing mechanical ventilation. PEEP is gradually increased and at 22 cm
H2O there is complete alveolar recruitment. In this patient, the consolidation
is recruitable.
➣ Echoguided venous access
e “central” venous access is usually used in critically ill patients. Echography allows detection of pervious vessels and the most suitable way for the achievement of the lumen78.
In this section, we will refer to the echo-guided puncture of the subclavian and the internal
jugular veins. Even these vessels are not entirely inside the chest, their echoguided access is
fundamental for the safe of the patient, and many related complications are chest related.
Catheterization of the internal jugular and subclavian veins has been carried out for years
through anatomical landmarks. However, the “blind” technique is subject to a significant
number of failures and complications, especially in emergency. In this setting, the acquisition is
Interventional chest ultrasound 477
possible in smaller percentages than in election (62% vs. 96%) and at a higher price of incidents
(8%). Numerous studies have unequivocally demonstrated the usefulness of ultrasound in this
79-82
area
. Today the central venous access should be implemented with ultrasound guidance.
Two meta-analysis have compared the echo-guided approach to central vessels with the blind
technique. Randolph and co-workers
83-84
studied eight trials (internal jugular and subclavian
cannulation), demonstrating that the use of ultrasound reduced the failures, and decreased
the complications and the attempts of cannulation of the vessel. In 2003, the British National
Institute for Clinical Excellence (NICE) published a meta-analysis of 18 randomized trials
related to echo-guided cannulations85. ere was evidence to support the use of ultrasound for
obtaining access to the internal jugular vein in adults, with lower failure rates and greater success in the first attempt. ese considerations, however, were not extended to children. Many
publications related to this topic in the setting of Emergency Medicine are available. Miller
and coworkers86 have compared the blind technique with the echo-guided puncture, demonstrating shorter acquisition times and less attempts, but a similar number of complications.
erefore, the great majority of studies supports the use of ultrasound as an aid to this type of
interventions in adults. e American College of Emergency Physicians87 published a statement on the use of ultrasound by emergency physicians, that reiterates the inclusion of this
technique in the list of primary applications of ultrasound in the Emergency Departments.
In our opinion each vascular access should be performed under ultrasound guidance. However,
in some situations, the ultrasound guidance is mandatory, especially in the case of the internal
jugular vein access. ese situations are shown in Table 13.
Table 13 – Situations in which the central venous cannulation under ultrasound guidance is necessary
• Training of operators
• Vascular Screening
• Difficult anatomy (short neck, obesity, cervical masses)
• Previous cervical surgery
• Anticoagulation
• Pathology of carotid
• Children
• Multiple previous punctures
• History of difficult cannulations
• Previous unsuccessful attempts
With blind technique, the puncture of the internal jugular vein occurs anteriorly or posteriorly
to the sternocleidomastoid (SCM), or through an access that takes place between the two
heads (sternal and clavicular) of the SCM, in the point where they separate. e subclavian
vein is punctured by under- or supraclavicular way, at a variable distance from the junction
with the internal jugular vein.
e most common complication of central venous access is represented by PNX (especially
when the subclavian vein, which runs a few millimeters before the pleural dome, is involved).
Other complications concern the puncture of a large arterial vessel, the injury of the thoracic
478 oracic ultrasound
duct (on the left) and hematoma formation88. Table 14 summarizes some peculiarities of the
blind subclavian and internal jugular veins cannulation.
Table 14 – Characteristics of the blind subclavian and internal jugular veins access
Seat
Internal jugular vein Superficial, easy control of the
Subclavicular
subclavian vein
Supraclavicular
subclavian vein
Advantages
bleeding. Direct way (to the
right) to the superior vena cava.
Low incidence of pneumothorax.
During the cannulation, the chest
is free for resuscitation maneuvers.
Superficiality.
Better management of the catheter
and comfort. Better landmarks in
obese and edematous patients.
Anatomical fixity and greater
volumetric stability of the vessel.
Intermediate incidence of
pneumothorax. Good landmarks.
Non-interference with resuscitation.
Disadvantages
Not ideal for long periods.
Uncomfortable for the patient,
suboptimal management of
the catheter. Landmarks are
difficult to visualize in obese or
edematous patients. Inconstant
anatomy. Risk of carotid
puncture. Left: risk of injury to
the thoracic duct.
Increased risk of pneumothorax.
Hard to compress in the event
of bleeding. Higher failure rates
of cannulation by inexperienced.
Deep anatomical situation.
Difficulty for controlling
bleeding. PNX. Not ideal for long
periods. Difficult management
of the catheter. Injury of the
thoracic duct (left).
RIGHT INTERNAL
JUGULAR VEIN
Figure 35 – Example of left dominance. In this patient, the diameter of the left internal jugular vein is
significantly larger than the right one and its cannulation will be easier.
LEFT INTERNAL
JUGULAR VEIN
Interventional chest ultrasound 479
Sonographic anatomy
For the cannulation of the internal jugular vein, the most constant landmark is the carotid
artery, never collapsed and easily recognizable by its pulsations. e internal jugular vein is
inconsistent in its position, but it is anterolateral to the common carotid artery in most cases.
e right internal jugular vein is often not dominant (32% of cases) and in such situations it
is preferable to approach the left internal jugular vein (Fig. 35). e anatomical variability of
the internal jugular veins explains the failures of cannulation and the complications related
to blind techniques (Fig. 36).
Position range in %
medial 0-5.5
anterior 0-16 (54*)
anterio-lateral 9-92
CA
far lateral 0-4
lateral 0-84
posterior 0-9
not visible/
medial
Figure 36 – Variability of position of the internal jugular vein compared to the common carotid artery
(from: Maecken T, Grau T. Ultrasound imaging in vascular access. Crit Care Med 2007; 35: S178-S185).
lateral
thrombosed
In the neck, a probe with a suitable frequency (> 7 MHz) shows skin and fascia as echogenic
lines; the subcutaneous tissue is relatively hypoechoic, while the muscles have the classic
structure with internal echoes. e internal jugular vein appears as an anechoic structure with
thin walls. It is tubular if explored longitudinally, and circular or elliptic (if not collapsed or
collapsible) if explored axially. It sometimes shows a spontaneous contrast within, is easily
compressible and with an axial representation it varies from a round to strongly elliptic shape.
ese features aid to differentiate the jugular vein from the common carotid artery. Moreover,
the artery pulsates and usually has a smaller diameter (Figs. 37-38).
e subclavian vein meets the internal jugular vein behind the medial head of the clavicle,
originating the brachiocephalic trunk. In echography this confl uence is incompletely rep-In echography this confluence is incompletely represented properly tilting the probe placed transversely to the base of the neck and on the
medial supraclavicular fossa. e course of the subclavian vein is seen from above (medially)
or below the clavicle (laterally). e vein is easy seen behind the anterior axillary pillar, where
it is already the axillary vein.
In the first case the venous trunk appears behind the clavicular head of the SCM in front of
the anterior scalene and the subclavian artery. In the second case the ultrasound beam passes
through the subcutaneous tissue, the bundles of the pectoralis major and displays the vein
between first rib and clavicle. In both cases, in depth, the artifacts of the lung tissue appear to
indicate the critical contiguity of the pleural dome with the vessel (around 5 mm) (Figs. 39-41).
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