Endobronchial coil implantation
The coil procedure (PneumRx Inc, Mountain View,
CA, USA) was developed for patients with
heterogeneous and homogenous emphysema
with interlobar collateral ventilation. The
procedure is performed under general anaesthesia
and fluoroscopy. Approximately 8 and 14 nitinol
coils (average of 10) are placed in the targeted
lobe using bronchoscopy. The length of the
airway is measured by the guide wire during the
procedure, and 100, 125, and 150mm coils are
used in the procedure. Using the carrier catheter,
the coil is advanced to the targeted bronchus,
but it is recommended not to place it too close
to the central vascular structures and pleura. 12
By pulling the catheter, the coil returns to its
original shape before it is loaded into the
catheter, thus reducing lung volume. The same
procedure is applied in the other lung within four
to eight weeks. Following the procedure, patients
are kept under observation for one to two days.
In order to obtain a good response, the patient
must have healthy parenchymal tissue in the
non-targeted lung areas. 6–8
severe emphysema. Values of patient forced
expiratory volume in 1 second (FEV1) should be
between 15% and 50% (15–45% for coil), and
findings indicating the presence of hyperinflation
(TLC >100%, RV >175%, RV/TLC ≥0.58) are
required. Although there is no clear evidence, it is
recommended by experts that these therapies
should be avoided in patients with hypercapnia
(PCO2 >55–60mmHg) and pulmonary
hypertension (PAB > 50mmHg). 7 Patient results
for the 6-minute walk test (6MWT) should be in
the range of 150–450m. Furthermore, these
expensive treatments are not recommended for
active smokers. To be considered for ELVR
treatment, patients should have quit smoking at
least two months prior; cessation of smoking six
months before is most ideal (Table 1).
Contraindications
These treatments are not recommended for
patients with clinically relevant bronchiectasis,
lung cancer, bullous lesions greater than 4cm,
history of prior lung surgery, severe hypoxia
(PaO2 <45mmHg), hypercapnia (PCO2 >55–60), or
in patients undergoing anticoagulation therapy. 7
In addition, these treatments are not
recommended in patients with impaired general
status or in those who have comorbidities that
might significantly affect survival. Other
contraindications include unstable cardiovascular
disease such as unstable arrhythmia, severe heart
failure (left ventricular ejection fraction <35%),
and stroke or myocardial infarction within the
last six months. 8 Although genetic α-1 antitrypsin
deficiency has been accepted as a criterion for
exclusion, discussion continues as to whether it
should be considered as a contraindication.
Procedure
The most frequently used and most evidence-
based ELVR methods are the valve and coil
procedures. Although their mechanisms of action
are different, these methods can be performed in
patients with both heterogeneous and
homogenous emphysema. The treatment
algorithm for these methods is shown in Figure
1. 1,9 The valves are fully reversible, and coils are
partially reversible, but it is not possible to
recycle all applied coils. 10
The most
important reason
for increasing
treatment
efficacy is correct
patient and
appropriate
treatment
method selection
Endobronchial valve implantation
The evaluation of collateral ventilation and the
fissure completeness score (FCS) is very important
prior to treatment. These evaluations are
performed by qualitative computed tomography
and via the Chartis system during bronchoscopy.
If the FCS and collateral flow are above 95%, valve
therapy can be applied directly. Measurement
with the Chartis system is required when
collateral flow is between 80% and 95%. However,
alternative endoscopic methods and surgeries
should be considered in patients with collateral
flow scores below 80%. 7 Under light sedation,
endobronchial valves are placed into
bronchoscopically targeted segmental bronchi.
Atelectasis and volume-reducing effects are
achieved after blocking the hyperinflated lung
lobe. Targeted lobar volume reduction is the
efficacy outcomes measure, which is considered
to be positive when a reduction of 350ml is
achieved. 11
Benefits
In the studies conducted to date, EBV treatment
resulted in an average increase in FEV1 values of
77.5ml (34.5–140.0ml), an increase in results of
the 6MWT of 40.8m (9.3–91.0m), and an average
decrease in RV values of 440ml (200–680ml). 6 In
addition, the following were observed: increased
patient quality of life, a St George’s Respiratory
Questionnaire (SGRQ) score decrease of 7.0 points,
a modified Medical Research Council (mMRC)
score decrease of 0.8 points, a BODE Index
decrease of 1.2 points, and increased exercise
tolerance. 7
In a review of the coil procedure, it was
reported that coil treatment resulted in an
average increase in FEV1 values of 130ml
(90–200ml), an increase in results for the 6MWT
of 47.0m (14.6–84.0m), and an average decrease
in RV values of 420ml (310–510ml). 6 A significant
increase in patient quality of life was also
observed (SGRQ –12 points). 7 Additionally,
improvements in scores of anxiety and depression
were recorded in this patient group. 13 In a recent
study, coil treatments were reported to cause
improvements in blood gas parameters in
patients with hypoxic or mild hypercapnic
respiratory failure. 14
Potential complications
Although ELVR therapies are minimally invasive
procedures, they can lead to various
complications due to the presence of COPD with
severe emphysema. Pneumothorax (17.3%), valve
migration (2.1%), pneumonia (1.7%), haemoptysis
(1.9%), respiratory failure (1.4%), and
exacerbations of COPD (0.9%) were reported in a
recent study after application of EBV procedures. 15
Pneumothoraces (86%) usually occur within the
first 72 hours, indicating that patients should be
hospitalised immediately for a minimum of 72
hours following the procedure. 16
COPD exacerbation (41.0%) is the most frequent
complication of coil procedures, followed by
pneumonia (14.8%), and pneumothorax (5.7%). 6
These complications may occur either
immediately after the procedure or during
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