Current Concepts in Lung Volume Reduction
November 18, 2013
James Canfield MBA/RPFT
Interventional Pulmonary Service
Emphysema
• Emphysema, along with chronic
bronchitis, together are referred to as
Chronic Obstructive Lung Disease
• Characterized by increase beyond
normal in the size of air spaces distal
to the terminal bronchiole containing
alveoli
• Destructive changes in their walls and
reduction in their number
• "Heterogeneous" and "homogenous“
- Heterogeneous is when
emphysema is more isolated to
certain areas of the lungs and the
extent of emphysema varies
between segments of the lungs.
- Homogenous is when emphysema
has a more diffuse pattern and it is
distributed more evenly throughout
the lungs
Morphological Types of Emphysema
• Centriacinar
- Begins in the respiratory bronchioles and spreads peripherally
- Also termed centrilobular emphysema
- Associated with long-standing cigarette smoking
- Predominantly involves the upper half of the lungs.
• Panacinar
- Destroys the entire alveolus uniformly
- Predominant in the lower half of the lungs
- Generally observed in patients with homozygous alpha1-antitrypsin
(AAT) deficiency
• Paraseptal
- Preferentially involves the distal airway structures, alveolar ducts, and
alveolar sacs
- Localized around the septae of the lungs or pleura
- Apical bullae may lead to spontaneous pneumothorax
3
Emphysema Clinical Manifestation
• Breathlessness on exertion
- Reduction of alveolar surface for gas exchange
- Collapse of smaller airways with trapping of
alveolar gas in expiration
• Causes the chest to be held in the position
of inspiration
• Prolonged expiration and increased residual
volume
4
Possible Complications of Emphysema
• Pneumothorax
- Can be fatal in patients with severe emphysema because the lungs
have become so weak
• Cor pulmonale
- Happens when pressure in the arteries that connect the lungs and
heart increases
• Giant bullae
- Sometimes half the size of the lung
- Lungs have a much smaller surface area
- The bullae can become infected
- More likely to develop pneumothorax
• Recurring infections
- Chest infections, pneumonia, influenza, cold and the common cold are
like to occur more often
• Pulmonary hypertension
5
Lung Volume Reduction Surgery
• Many people who suffer with emphysema have portions of
the lung which are more affected than others
• This finding led to the development of a surgical approach
to treat emphysema
- Lung volume reduction surgery (LVRS) is a procedure which
removes approximately 20-35% of the poorly functioning,
space occupying lung tissue from each lung
- By reducing the lung size, the remaining lung and surrounding
muscles (intercostals and diaphragm) are able to work more
efficiently
• This makes breathing easier and helps patients achieve
greater quality of life
6
Lung Volume Reduction Surgery
• Good Candidates
- Has stopped smoking for at least 4 months
- Has disabling emphysema despite complete compliance with
optimum medical therapy
- Must be able to participate in a pulmonary rehabilitation
program prior to and after surgery
- Other medical conditions must be well controlled and must not
present unacceptable risks for complications from the
procedure
- Must have a pattern of emphysema that is amenable to
surgical management
• There are space occupying, poorly functioning areas of the
lung which can be removed to improve lung function
- Chest x-ray, CAT scan, and lung perfusion studies
7
Lung Volume Reduction Surgery
• The National Emphysema Treatment Trial (NETT)
- Group 1: Patients with predominantly upper lobe emphysema
and low exercise capacity
• Have improved survival and functional outcomes after
LVRS compared to medical therapy.
- Group 2: Patients with predominantly upper lobe emphysema
and high exercise capacity
• Have improved functional outcomes after LVRS but no
difference in survival compared to medical therapy.
- Group 3: Patients with non-upper lobe emphysema and low
exercise capacity
• Have improved survival after LVRS but no difference in
survival compared to medical therapy.
8
Lung Volume Reduction Surgery
• Anticipated Benefits
- As overall hyperinflation
decreases, diaphragm and
chest wall mechanics would
improve and WOB would
decrease
- Increase in elastic recoil
thereby restoring the
outward pull on bronchioles
and increase expiratory flow
- Increase flow would decrease
dynamic hyperinflation
- Improvement in ventilation
and profusion matching
improves alveolar gas
exchange which in turn may
decrease need for
supplemental oxygen
thoracicsurgery.stanford.edu
9
Lung Volume Reduction Surgery
thoracicsurgery.stanford.edu
10
Lung Volume Reduction Surgery
• Poor Candidates
- Patients with non-upper lobe emphysema and high
exercise capacity.
- Patients with extremely poor pulmonary function (FEV1
20% or less than predicted) and either homogenous
distribution of emphysema on CT scan or extremely
poor carbon monoxide diffusing capacity (DLCO 20% or
less than predicted).
11
Potential Complications
• Prolonged air leakage is the most common complication after
LVRS, Air leaks with a median 7-day duration have also been
reported in 90% of patients
• Intraoperative complications (9%)
• Postoperative complications (50%)
- Pneumonia (18.2%) can occur in emphysema patients,
especially in patients who have a history of recurrent bouts
- Reintubation (21.8%)
- Arrthymias (18.6%)
- Bleeding (2-5%)
- Death: The chance of dying after LVRS is approximately 3-8%
Lessons learned from the National Emphysema Treatment Trial. Ann Thorac Surg 82:197-207, 2006
12
Bronchoscopic Lung Volume Reduction (bLVR)
LVRS application is limited by high postoperative morbidity
and stringent selection criteria that effectively exclude many
patients. This has been the impetus for the development of
less-invasive approaches to lung volume reduction
In the last decade bronchoscopic approaches have been
developed to reproduce the effects of LVRS:
• Valves that allow unidirectional airflow in exhalation to
collapse target lung lobe
• Biological lung volume reduction with biodegradable gel
into bronchi
• Creation of airway bypass tracts
• Coils
• Thermal vapor ablation
13
Rationale for bLVR
• Use of endoscopic methods to collapse of
hyperinflation would have the beneficial effects
similar to resecting these areas without the
morbidity of surgery
• Patients not a good surgical candidates might be
able to undergo bLVR
14
Active Randomized Clinical Trials of
Bronchoscopic Lung Volume Reduction
FDA-Approved TRIALS
ASPIRE
RENEW
LIBERATE
LVR Coil
EBV, Chartis
Device(s)
Aeriseal
Sample Size
300
315
183
Randomization Schema
3:2
1:1
2:1
Treatment
Bilateral
Bilateral-staged
Unilateral
Primary Endpoint
FEV1
6-minute walk
FEV1
Sponsor
Aeris
PneumRx
Pulmonx
(foam)
Therapeutics
15
Bronchoscopic Lung Volume Reduction
• Bronchial Valves
- The intrabronchial
valve (Spiration Inc.,
Redmond, WA, USA)
has six struts made of
nitinol covered by
polyurethane
membrane in the shape
of an umbrella
Thorac Surg Clin 19:247-253, 2009
16
Bronchoscpic Lung Volume Reduction
• The Zephyr endobronchial
valve (Pulmonx Inc., Palo
Alto, CA, USA) is a one
way valve that is mounted
on a self-expanding
nitinol stent. The
endobronchial valve (EBV)
allows unidirectional
airflow mucus clearance in
expiration and is available
in various sizes
N Engl J Med 363:1233-1244, 2010
17
The RePneu® LVRC
• A minimally invasive medical implant designed to treat the
symptoms of severe emphysema
• Unlike Lung Volume Reduction Surgery, the RePneu LVRC is
intended to treat a broad range of emphysema patients
• Is designed to reduce lung volume and restore elastic recoil to
improve lung function, exercise capacity, and quality of life for
patients with emphysema
• Made from shape-memory Nitinol
• The Coils are straightened for insertion into your airways, and
then reform their coiled shape once they are released from the
bronchoscope, gently compressing the surrounding
diseased lung tissue and tethering the small airways open
18
The RePneu® LVRC
19
The RePneu® LVRC
20
The RePneu® LVRC
21
RENEW
• This Study is a randomized,
controlled study in which half of
the patients (Coil group) will
receive LVRC. Half of the patients
will not receive Coils (Control
group)
•
All participants will continue to
receive Standard Medical Care
and will be followed by the study
staff for 12 months
• Up to 315 patients will participate
in this study. The study will be
conducted in over 25 medical
centers across North America,
with a smaller number of sites in
Europe
22
The RePneu® LVRC
23
EL CAMINO HOSPITAL
INTERVENTIONAL PULMONARY SERVICE
24
25