U.S. patent application number 11/509871 was filed with the patent office on 2006-12-21 for methods and devices for inducing collapse in lung regions fed by collateral pathways.
Invention is credited to Antony J. Fields, Ronald Hundertmark, John McCutcheon.
Application Number | 20060283462 11/509871 |
Document ID | / |
Family ID | 27805274 |
Filed Date | 2006-12-21 |
United States Patent
Application |
20060283462 |
Kind Code |
A1 |
Fields; Antony J. ; et
al. |
December 21, 2006 |
Methods and devices for inducing collapse in lung regions fed by
collateral pathways
Abstract
Disclosed are methods and devices for treating a patient's lung
region. A catheter is deployed into the lung. The catheter is used
to apply heat to a targeted lung region wherein the heat affects
fluid flow within the targeted lung region.
Inventors: |
Fields; Antony J.; (San
Francisco, CA) ; Hundertmark; Ronald; (San Mateo,
CA) ; McCutcheon; John; (Menlo Park, CA) |
Correspondence
Address: |
FISH & RICHARDSON, PC
P.O. BOX 1022
MINNEAPOLIS
MN
55440-1022
US
|
Family ID: |
27805274 |
Appl. No.: |
11/509871 |
Filed: |
August 25, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10384899 |
Mar 6, 2003 |
|
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11509871 |
Aug 25, 2006 |
|
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60363328 |
Mar 8, 2002 |
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Current U.S.
Class: |
128/207.14 ;
128/200.24; 128/205.24; 128/207.15; 128/207.16 |
Current CPC
Class: |
A61B 17/00491 20130101;
A61F 2/2418 20130101; A61F 2002/043 20130101; A61F 2/2412 20130101;
A61F 2/2427 20130101; A61F 2/91 20130101; A61F 2/04 20130101; F16K
15/147 20130101; A61F 2/06 20130101 |
Class at
Publication: |
128/207.14 ;
128/200.24; 128/205.24; 128/207.15; 128/207.16 |
International
Class: |
A61M 16/00 20060101
A61M016/00; A62B 7/00 20060101 A62B007/00 |
Claims
1. A method of treating a patient's lung region, comprising:
deploying a catheter into a lung; using the catheter to apply heat
to a targeted lung region wherein the heat affects fluid flow
within the targeted lung region.
2. A method as in claim 1, wherein the heat reduces or terminates
fluid flow within the targeted lung region.
3. A method as in claim 1, wherein the heat generates a reaction in
tissue of the targeted lung region that results in a reduction or
prevention of fluid flow within the targeted lung region.
4. A method as in claim 1, wherein the heat seals portions of the
lung together.
5. A method as in claim 1, wherein the heat scleroses lung tissue
within the targeted lung region
6. A method as in claim 1, wherein the heat promotes fibrosis in or
around the targeted lung region
7. A method as in claim 1, wherein the heat creates an inflammatory
response in the targeted lung region.
8. A method as in claim 1, wherein the heat affects fluid flow by
reducing or preventing collateral fluid flow into the targeted lung
region.
9. A method as in claim 1, wherein deploying a catheter into a lung
comprises deploying a catheter through a bronchial tree into the
targeted lung region such that a distal end of the catheter is
positioned near the targeted lung region.
10. A method as in claim 9, wherein the heat is applied via the
distal end of the delivery catheter.
Description
REFERENCE TO PRIORITY DOCUMENTS
[0001] This application is a continuation of co-pending U.S. patent
application Ser. No. 10/384,899 entitled "Methods and Devices for
Inducing Collapse in Lung Regions Fed by Collateral Pathways",
filed Mar. 6, 2003, which claims priority of U.S. Provisional
Patent Application Ser. No. 60/363,328 entitled "Methods and
Devices for Inducing Collapse in Lung Regions Fed by Collateral
Pathways", filed Mar. 8, 2002. Priority of the aforementioned
filing dates is hereby claimed, and the disclosures of the
aforementioned patent application are hereby incorporated by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to methods and devices for
use in performing pulmonary procedures and, more particularly, to
procedures for treating various diseases of the lung.
[0004] 2. Description of the Related Art
[0005] Pulmonary diseases such as chronic obstructive pulmonary
disease (COPD) reduce the ability of one or both lungs to fully
expel air during the exhalation phase of the breathing cycle. The
term "Chronic Obstructive Pulmonary Disease" (COPD) refers to a
group of diseases that share a major symptom, dyspnea. Such
diseases are accompanied by chronic or recurrent obstruction to air
flow within the lung. Because of the increase in environmental
pollutants, cigarette smoking, and other noxious exposures, the
incidence of COPD has increased dramatically in the last few
decades and now ranks as a major cause of activity-restricting or
bed-confining disability in the United States. COPD can include
such disorders as chronic bronchitis, bronchiectasis, asthma, and
emphysema. While each has distinct anatomic and clinical
considerations, many patients may have overlapping characteristics
of damage at both the acinar (as seen in emphysema) and the
bronchial (as seen in bronchitis) levels, almost certainly because
one pathogenic mechanism--cigarette smoking is common to both.
(Robbins eds., Pathological Basis of Disease, 5.sup.th edition, pg
683)
[0006] Emphysema is a condition of the lung characterized by the
abnormal permanent enlargement of the airspaces distal to the
terminal bronchiole, accompanied by the destruction of their walls,
and without obvious fibrosis. It is known that emphysema and other
pulmonary diseases reduce the ability of one or both lungs to fully
expel air during the exhalation phase of the breathing cycle. One
of the effects of such diseases is that the diseased lung tissue is
less elastic than healthy lung tissue, which is one factor that
prevents full exhalation of air. During breathing, the diseased
portion of the lung does not fully recoil due to the diseased
(e.g., emphysematic) lung tissue being less elastic than healthy
tissue. Consequently, the diseased lung tissue exerts a relatively
low driving force, which results in the diseased lung expelling
less air volume than a healthy lung. The reduced air volume exerts
less force on the airway, which allows the airway to close before
all air has been expelled, another factor that prevents full
exhalation.
[0007] The problem is further compounded by the diseased, less
elastic tissue that surrounds the very narrow airways that lead to
the alveoli (the air sacs where oxygen-carbon dioxide exchange
occurs). This tissue has less tone than healthy tissue and is
typically unable to maintain the narrow airways open until the end
of the exhalation cycle. This traps air in the lungs and
exacerbates the already-inefficient breathing cycle. The trapped
air causes the tissue to become hyper-expanded and no longer able
to effect efficient oxygen-carbon dioxide exchange. One way of
deflating the diseased portion of the lung is to applying suction
to these narrow airways. However, such suction may undesirably
collapse the airways, especially the more proximal airways, due to
the surrounding diseased tissue, thereby preventing successful
fluid removal.
[0008] In addition, hyper-expanded lung tissue occupies more of the
pleural space than healthy lung tissue. In most cases, a portion of
the lung is diseased while the remaining part is relatively healthy
and therefore still able to efficiently carry out oxygen exchange.
By taking up more of the pleural space, the hyper-expanded lung
tissue reduces the amount of space available to accommodate the
healthy, functioning lung tissue. As a result, the hyper-expanded
lung tissue causes inefficient breathing due to its own reduced
functionality and because it adversely affects the functionality of
adjacent, healthier tissue.
[0009] Lung volume reduction surgery is a conventional method of
treating lung diseases such as emphysema. According to the lung
reduction procedure, a diseased portion of the lung is surgically
removed, which makes more of the pleural space available to
accommodate the functioning, healthier portions of the lung. The
lung is typically accessed through a median sternotomy or lateral
thoracotomy. A portion of the lung, typically the upper lobe of
each lung, is freed from the chest wall and then resected, e.g., by
a stapler lined with bovine pericardium to reinforce the lung
tissue adjacent the cut line and also to prevent air or blood
leakage. The chest is then closed and tubes are inserted to remove
fluid from the pleural cavity. The conventional surgical approach
is relatively traumatic and invasive, and, like most surgical
procedures, is not a viable option for all patients.
[0010] Some recently proposed treatments include the use of devices
that isolate a diseased region of the lung in order to reduce the
volume of the diseased region, such as by collapsing the diseased
lung region. According to such treatments, isolation devices are
implanted in airways feeding the targeted region of the lung to
isolate the region of the lung targeted for volume reduction or
collapse. These implanted isolation devices can be, for example,
one-way valves that allow flow in the exhalation direction only,
occluders or plugs that prevent flow in either direction, or
two-way valves that control flow in both directions. However, even
with the implanted isolation devices properly deployed, air can
flow into the isolated lung region via a collateral pathway. This
can result in the diseased region of the lung still receiving air
even though the isolation devices were implanted into the direct
pathways to the lung. Collateral flow can be, for example, air flow
that flows between segments of a lung, or it can be, for example,
air flow that flows between lobes of a lung, as described in more
detail below.
[0011] Collateral flow into an isolated lung region can make it
difficult to achieve a desired flow dynamic for the lung region.
Moreover, it has been shown that as the disease progresses, the
collateral flow throughout the lung can increase, which makes it
even more difficult to properly isolate a diseased lung region by
simply implanting flow control valves in the bronchial passageways
that directly feed air to the diseased lung region.
[0012] In view of the foregoing, there is a need for a method and
device for regulating fluid flow to and from a region of a lung
that is supplied air through a collateral pathway, such as to
achieve a desired flow dynamic or to induce collapse in the lung
region.
SUMMARY
[0013] Disclosed are methods and devices for regulating fluid flow
to and from a lung region that is supplied air through one or more
collateral pathways, such as to induce collapse in the lung region
or to achieve a desired flow dynamic. In accordance with one aspect
of the invention, there is disclosed a method of regulating fluid
flow for a targeted lung region, comprising identifying at least
one collateral pathway that provides collateral fluid flow into the
targeted lung region and performing an intervention within the lung
to reduce the amount of collateral fluid flow provided to the
targeted lung region through the collateral pathway. The method can
also include identifying at least one direct pathway that provides
direct fluid flow into the targeted lung region and deploying a
bronchial isolation device in the direct pathway to regulate fluid
flow to the targeted lung region through the direct pathway.
[0014] Also disclosed is a method of regulating fluid flow for a
targeted lung region, comprising reducing direct fluid flow in a
direct pathway that provides direct fluid flow to the targeted lung
region; and reducing collateral fluid flow that flows through a
collateral pathway to the targeted lung region.
[0015] Also disclosed is a method of treating a patient's lung
region, comprising deploying a catheter into a lung; and using the
catheter to apply heat to a targeted lung region wherein the heat
affects fluid flow within the targeted lung region.
[0016] Other features and advantages of the present invention
should be apparent from the following description of various
embodiments, which illustrate, by way of example, the principles of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 illustrates an anterior view of a pair of human lungs
and a bronchial tree.
[0018] FIG. 2 illustrates a lateral view of the right lung.
[0019] FIG. 3 illustrates a lateral view of the left lung.
[0020] FIG. 4 illustrates an anterior view of the trachea and a
portion of the bronchial tree.
[0021] FIG. 5 illustrates an anterior view of a lung having a lung
lobe that is receiving collateral air flow through a collateral
pathway comprised of an incomplete interlobar fissure.
[0022] FIG. 6 illustrates an anterior view of a lung having a lung
segment that is receiving collateral air flow.
[0023] FIG. 7 illustrates the delivery of a flowable therapeutic
agent to a targeted lung region using a balloon-tipped delivery
catheter.
[0024] FIG. 8 illustrates the delivery of a flowable therapeutic
agent to a targeted lung region using a delivery catheter.
[0025] FIG. 9 illustrates the percutaneous injection of a flowable
therapeutic agent to a targeted lung region.
[0026] FIG. 10 illustrates the injection of a flowable therapeutic
agent into a targeted lung region through a catheter that has a
sharpened tip.
[0027] FIG. 11 illustrates the deployment of a delivery catheter in
a patient using a bronchoscope.
[0028] FIG. 12 illustrates a lateral view of the right lung,
showing a targeted lung region and an adjacent healthy lung
region.
[0029] FIG. 13 illustrates the injection of a therapeutic agent
into a targeted lung region, controlled by applied pressure in an
adjacent lung region.
[0030] FIG. 14 illustrates the treatment of collateral flow paths
using a beta-emitting radiation source.
[0031] FIG. 15 illustrates the treatment of collateral flow paths
using flow-limiting isolation devices.
[0032] FIG. 16 illustrates the percutaneous suction of a targeted
lung region using a suction catheter.
[0033] FIG. 17 illustrates the sealing of collateral flow paths
between the right upper lobe and the right middle lobe through the
use of a two-part adhesive.
[0034] FIG. 18 illustrates the use of shunt tubes that are mounted
in bronchial passageway to provide free air pathways to a targeted
lung region.
[0035] FIG. 19 is a cross-sectional view of a flow control element
that allows fluid flow in a first direction but blocks fluid flow
in a second direction.
[0036] FIG. 20 shows a perspective view of another embodiment of a
flow control element.
[0037] FIG. 21 shows a cross-sectional, perspective view of the
flow control element of FIG. 21.
[0038] FIG. 22 shows a valve element.
[0039] FIG. 23 shows a side view of the valve element of FIG.
22.
[0040] FIG. 24 shows a cross-sectional view of the valve element of
FIG. 22 along the line 24-24 of FIG. 23.
[0041] FIG. 25 shows an enlarged, sectional view of the portion of
the flow control element contained within line 25 of FIG. 22.
DETAILED DESCRIPTION
[0042] Unless defined otherwise, all technical and scientific terms
used herein have the same meaning as is commonly understood by one
of skill in the art to which the invention(s) belong.
[0043] Disclosed are methods and devices for regulating fluid flow
to and from a region of a patient's lung, such as to achieve a
desired fluid flow dynamic to a lung region during respiration
and/or to induce collapse in one or more lung regions that are
supplied air through one or more collateral pathways. An identified
region of the lung (referred to herein as the "targeted lung
region") is targeted for flow regulation, such as to achieve volume
reduction or collapse. The targeted lung region is then bronchially
isolated to regulate fluid flow to the targeted lung region through
bronchial pathways that directly feed fluid to the targeted lung
region. If a desired flow characteristic to the targeted region is
not achieved, or if the targeted lung region does not collapse
after bronchially isolating the targeted lung region, then it is
possible that a collateral pathway is feeding air to the targeted
lung region. The collateral flow can prevent the targeted lung
region from collapsing. In such a case, the collateral pathway is
identified and an intervention is performed within the lung to
modify or inhibit fluid flow into the targeted lung region via the
collateral pathway, such as according to the methods described
herein. While the invention can involve such treatment of
collateral flow pathways in combination with bronchial isolation,
it should be understood that the invention may also be practiced
without bronchial isolation in some circumstances. Further, the
invention also encompasses temporary bronchial isolation while
treating lung regions fed by collateral pathways.
Exemplary Lung Regions
[0044] Throughout this disclosure, reference is made to the term
"lung region". As used herein, the term "lung region" refers to a
defined division or portion of a lung. For purposes of example,
lung regions are described herein with reference to human lungs,
wherein some exemplary lung regions include lung lobes and lung
segments. Thus, the term "lung region" as used herein can refer,
for example, to a lung lobe or a lung segment. Such nomenclature
conform to nomenclature for portions of the lungs that are known to
those skilled in the art. However, it should be appreciated that
the term lung region does not necessarily refer to a lung lobe or a
lung segment, but can refer to some other defined division or
portion of a human or non-human lung.
[0045] FIG. 1 shows an anterior view of a pair of human lungs 110,
115 and a bronchial tree 120 that provides a fluid pathway into and
out of the lungs 110, 115 from a trachea 125, as will be known to
those skilled in the art. As used herein, the term "fluid" can
refer to a gas, a liquid, or a combination of gas(es) and
liquid(s). For clarity of illustration, FIG. 1 shows only a portion
of the bronchial tree 120, which is described in more detail below
with reference to FIG. 4.
[0046] Throughout this description, certain terms are used that
refer to relative directions or locations along a path defined from
an entryway into the patient's body (e.g., the mouth or nose) to
the patient's lungs. The path of airflow into the lungs generally
begins at the patient's mouth or nose, travels through the trachea
into one or more bronchial passageways, and terminates at some
point in the patient's lungs. For example, FIG. 1 shows a path 102
that travels through the trachea 125 and through a bronchial
passageway into a location in the right lung 110. The term
"proximal direction" refers to the direction along such a path 102
that points toward the patient's mouth or nose and away from the
patient's lungs. In other words, the proximal direction is
generally the same as the expiration direction when the patient
breathes. The arrow 104 in FIG. 1 points in the proximal or
expiratory direction. The term "distal direction" refers to the
direction along such a path 102 that points toward the patient's
lung and away from the mouth or nose. The distal direction is
generally the same as the inhalation or inspiratory direction when
the patient breathes. The arrow 106 in FIG. 1 points in the distal
or inhalation direction.
[0047] The lungs include a right lung 110 and a left lung 115. The
right lung 110 includes lung regions comprised of three lobes,
including a right upper lobe 130, a right middle lobe 135, and a
right lower lobe 140. The lobes 130, 135,140 are separated by two
interlobar fissures, including a right oblique fissure 126 and a
right transverse fissure 128. The right oblique fissure 126
separates the right lower lobe 140 from the right upper lobe 130
and from the right middle lobe 135. The right transverse fissure
128 separates the right upper lobe 130 from the right middle lobe
135.
[0048] As shown in FIG. 1, the left lung 115 includes lung regions
comprised of two lobes, including the left upper lobe 150 and the
left lower lobe 155. An interlobar fissure comprised of a left
oblique fissure 145 of the left lung 115 separates the left upper
lobe 150 from the left lower lobe 155. The lobes 130, 135, 140,
150, 155 are directly supplied air via respective lobar bronchi, as
described in detail below.
[0049] FIG. 2 is a lateral view of the right lung 110. The right
lung 110 is subdivided into lung regions comprised of a plurality
of bronchopulmonary segments. Each bronchopulmonary segment is
directly supplied air by a corresponding segmental tertiary
bronchus, as described below. The bronchopulmonary segments of the
right lung 110 include a right apical segment 210, a right
posterior segment 220, and a right anterior segment 230, all of
which are disposed in the right upper lobe 130. The right lung
bronchopulmonary segments further include a right lateral segment
240 and a right medial segment 250, which are disposed in the right
middle lobe 135. The right lower lobe 140 includes bronchopulmonary
segments comprised of a right superior segment 260, a right medial
basal segment (which cannot be seen from the lateral view and is
not shown in FIG. 2), a right anterior basal segment 280, a right
lateral basal segment 290, and a right posterior basal segment
295.
[0050] FIG. 3 shows a lateral view of the left lung 115, which is
subdivided into lung regions comprised of a plurality of
bronchopulmonary segments. The bronchopulmonary segments include a
left apical segment 310, a left posterior segment 320, a left
anterior segment 330, a left superior segment 340, and a left
inferior segment 350, which are disposed in the left lung upper
lobe 150. The lower lobe 155 of the left lung 115 includes
bronchopulmonary segments comprised of a left superior segment 360,
a left medial basal segment (which cannot be seen from the lateral
view and is not shown in FIG. 3), a left anterior basal segment
380, a left lateral basal segment 390, and a left posterior basal
segment 395.
[0051] FIG. 4 shows an anterior view of the trachea 125 and a
portion of the bronchial tree 120, which includes a network of
bronchial passageways, as described below. In the context of
describing the lung, the terms "pathway" and "lumen" are used
interchangeably herein. The trachea 125 divides at a lower end into
two bronchial passageways comprised of primary bronchi, including a
right primary bronchus 410 that provides direct air flow to the
right lung 110, and a left primary bronchus 415 that provides
direct air flow to the left lung 115. Each primary bronchus 410,
415 divides into a next generation of bronchial passageways
comprised of a plurality of lobar bronchi. The right primary
bronchus 410 divides into a right upper lobar bronchus 417, a right
middle lobar bronchus 420, and a right lower lobar bronchus 422.
The left primary bronchus 415 divides into a left upper lobar
bronchus 425 and a left lower lobar bronchus 430. Each lobar
bronchus, 417, 420, 422, 425, 430 directly feeds fluid to a
respective lung lobe, as indicated by the respective names of the
lobar bronchi. The lobar bronchi each divide into yet another
generation of bronchial passageways comprised of segmental bronchi,
which provide air flow to the bronchopulmonary segments discussed
above.
[0052] As is known to those skilled in the art, a bronchial
passageway defines an internal lumen through which fluid can flow
to and from a lung. The diameter of the internal lumen for a
specific bronchial passageway can vary based on the bronchial
passageway's location in the bronchial tree (such as whether the
bronchial passageway is a lobar bronchus or a segmental bronchus)
and can also vary from patient to patient. However, the internal
diameter of a bronchial passageway is generally in the range of 3
millimeters (mm) to 10 mm, although the internal diameter of a
bronchial passageway can be outside of this range. For example, a
bronchial passageway can have an internal diameter of well below 1
mm at locations deep within the lung.
Direct and Collateral Flow
[0053] Throughout this disclosure, reference is made to a "direct
pathway" to a targeted lung region and to a "collateral pathway" to
a targeted lung region. The term "direct pathway" refers to a
bronchial passageway that branches directly or indirectly from the
trachea and either (1) terminates in the targeted lung region to
thereby directly provide air to the targeted lung region; or (2)
branches into at least one other bronchial passageway that
terminates in the targeted lung region to thereby directly provide
air to the targeted lung region. The term "collateral pathway"
refers to any pathway that provides air to the targeted lung region
and that is not a direct pathway. The term "direct" is used to
refer to air flow that flows into or out of a targeted lung region
via a direct pathway. Likewise, the term "collateral" is used to
refer to fluid flow (such as air flow) that flows into or out of a
targeted lung region via a collateral pathway. Thus, for example,
"direct" flow is fluid flow (such as air flow) that enters or exits
the targeted lung region via a direct pathway, and "collateral"
flow is fluid flow (such as air flow) that enters or exits the
targeted lung region via a collateral pathway.
[0054] A collateral flow can be, for example, air flow that flows
between segments of a lung, which is referred to as intralobar
flow, or it can be, for example, air flow that flows between lobes
of a lung, which is referred to as interlobar flow. One exemplary
process of identifying a collateral pathway that provides
collateral air flow into a targeted lung region is described
below.
[0055] In accordance with one aspect of the disclosed methods, a
targeted region of the lung is identified, wherein the targeted
lung region can comprise, for example, a single one of the lung
regions described above with reference to FIGS. 1-3, or the
targeted lung region can comprise a collection of the regions
described above. Alternately, the targeted lung region can be some
other portion of the lung. The targeted lung region can be, for
example, a diseased lung region for which it is desired to
bronchially isolate the region for the purposes of inhibiting fluid
flow into the region. As used herein, to "bronchially isolate" a
lung region means to modify the flow to the targeted lung region,
such as to regulate, prevent, or inhibit direct air flow to the
lung region. In one embodiment, after the targeted lung region is
identified, an attempt is made to bronchially isolate the targeted
lung region, such as by occluding the bronchial pathway(s) that
directly feed air to the targeted lung region. This may be
accomplished, for example, by advancing and implanting a bronchial
isolation device into the one or more bronchial pathways that
directly feed air to the targeted lung region to thereby regulate
direct flow into the lung region.
[0056] The bronchial isolation device can be, for example, a device
that regulates the flow of air into a lung region through a
bronchial passageway. Some exemplary bronchial isolation devices
comprised of flow control elements are described in detail below
with reference to FIG. 19-25. In addition, the following references
describe exemplary flow control elements: U.S. Pat. No. 5,594,766
entitled "Body Fluid Flow Control Device; U.S. patent application
Ser. No. 09/797,910, entitled "Methods and Devices for Use in
Performing Pulmonary Procedures"; and U.S. patent application Ser.
No. 10/270,792, entitled "Bronchial Flow Control Devices and
Methods of Use". The foregoing references are all incorporated
herein by reference in their entirety and are all assigned to
Emphasys Medical, Inc., the assignee of the instant
application.
[0057] If the targeted lung region does not collapse, then it can
be assumed that the targeted lung region is not collapsing because
of collateral air flow into the lung. In such a case, it is
desirable to modify collateral flow into the targeted lung region
in order to encourage collapse or to achieve a desired flow dynamic
for the lung region. For example, the collateral flow into the
targeted lung region can be completely prevented so that there is
no collateral flow into the targeted lung region. Alternately, the
collateral flow into the targeted lung region can simply be
reduced, such as to minimize the effect of the collateral flow on
the targeted lung region.
Use of Flowable Therapeutic Agents to Reduce or Prevent Collateral
Flow
[0058] One way of impeding collateral fluid flow into the targeted
lung region is by injecting one or more flowable therapeutic agents
into the targeted lung region in order to partially or completely
seal the collateral pathway(s) that are providing collateral flow
into the targeted lung region. The agent is "flowable" in that the
agent is at least initially in a fluid state, which can be, for
example, a liquid, gas, aerosol, etc. The agent is "therapeutic" in
that, when the agent contacts lung tissue, the agent generates a
reaction in the tissue of the targeted lung region that serves to
reduce, inhibit, or prevent collateral fluid flow into the targeted
lung region. The reaction can result in, for example (1) gluing or
sealing portions of the targeted lung region together to thereby
seal collateral pathways; (2) sclerosing or scarring target lung
tissue to thereby occlude the collateral pathway(s) and seal off
collateral flow into the targeted lung region; (3) promoting
fibrosis in or around the targeted lung region to thereby seal off
collateral flow into the region; (4) creating of an inflammatory
response that would seal or fuse collateral pathway(s) that lead
into the targeted lung region; (5) or creation of a bulking agent
that fills space (such as space within the targeted lung region
and/or the collateral pathway) and thereby partially or entirely
seal off collateral flow into the targeted lung region.
[0059] A variety of flowable therapeutic agents have been
identified that achieve one or more of the above reactions in lung
tissue. The agents include, for example, the following:
[0060] (1) a foam created from either synthetic materials or
natural biological materials that has one or more of the
following-described properties. According to one property, the foam
expands in volume from an initial injected volume to an expanded
volume by a predetermined volume amount. For example, the foam may
double in volume from an injected volume to expanded volume. Such
volume expansion would cause the foam to fill-up and seal the
volume of the targeted lung region or the volume of a collateral
pathway. According to another property, the foam can be resorbable
or degradable in the tissue of a patient's body, such that, when
the foam is injected into the targeted lung region, the targeted
lung region would absorb the foam and shrink in volume. For
example, the foam could comprise a biodegradable polymer, such as
polyethylene glycol (PEG) or polyglycolic acid (PGA). In another
example, the foam could be a biodegradable polymer that is foamed
with hydrogen or some other gas and that is permeable through the
cellular structure of the foam.
[0061] When a foam as described above is injected into the targeted
lung region, gas would begin to diffuse out of the foam matrix,
which would cause cells within the foam to collapse. As the foam
collapses, the adjacent tissue will be drawn to a smaller volume
simultaneously due to adhesion between the foam and the surrounding
tissue. In one embodiment, the foam has balanced properties of flow
and viscosity in order to increase the likelihood that the foam
will adequately fill the targeted lung region. Such balanced
properties would also reduce the likelihood of the foam running or
leaking into regions of the lung adjacent to the targeted lung
region through the collateral pathway(s). The foam can retain a
foamy consistency until it is absorbed into the lung tissue, or it
can cure and harden and then dissolve over time.
[0062] (2) A sealant or glue, such as, for example, fibrin,
fibrinogen and thrombin epoxy, various cyanoacrylate adhesives and
sealants, such as n-butyl-2-cyanoacrylate, synthetic biocompatible
sealants made from polyethylene polymers, etc.
[0063] (3) Sclerosing agents such as, for example, doxycycline,
minocycline, tetracycline, bleomycin, cisplatin, doxorubicin,
fluorouracil, interferon-beta, mitomycin-c, Corynebacterium parvum,
methylprednisolone, and talc.
[0064] (4) Antibiotics such as, for example, doxycycline,
minocycline or bleomycin, tetracycline, etc.
[0065] (5) Bulking agents such as, for example, collagen, gelatin,
Gelfoam, or Surgicel solutions, polyvinyl acetate (PVA), ethylene
vinyl alcohol copolymer (EVAL) or ethylene vinyl alcohol copolymer
solutions.
[0066] One example of an appropriate bulking material is the Onyx
Liquid Embolic System manufactured by Micro Therapeutics, Irvine,
Calif. This material is ethylene vinyl alcohol copolymer combined
with micronized tantalum powder for fluoroscopy contrast dissolved
in dimethl sulfoxide (DMSO) solvent. It solidifies through
precipitation upon contact with an aqueous solution, such as
saline, and forms a spongy mass.
[0067] (6) Agents for inducing a localized infection and scar such
as, for example, a weak strain of Pneumococcus.
[0068] (7) Other agents such as mucolytics (to reduce or eliminate
mucus), steroids, factor XIIIa transglutaminase.
[0069] (8) Fibrosis promoting agents such as a polypeptide growth
factor (fibroblast growth factor (FGF), basic fibroblast growth
factor (bFGF), transforming growth factor-beta (TGF-.beta.))
[0070] (9) Pro-apoptopic agents such as sphingomyelin, Bax, Bid,
Bik, Bad, caspase-3, caspase-8, caspase-9, or annexin V.
[0071] (10) Components of the extracellular matrix (ECM) such as
hyaluronic acid (HA), chondroitin sulfate (CS), fibronectin (Fn),
or ECM-like substances such as poly-L-lysine or peptides consisting
of praline and hydroxyproline.
[0072] Any well-known radiopaque contrast agent could be added to
the therapeutic agent in order to facilitate viewing of the agent
as it is dispersed in the targeted lung region. A sufficient
quantity of agent is dispersed to seal collateral pathways, but not
so much that adjacent tissue is affected. The flowable therapeutic
agents that can be used to limit collateral flow into a targeted
lung region are not limited to those described above.
Identification of Regions for Treatment
[0073] As discussed above, the targeted lung region can be an
entire lobe of one of the lungs 110, 115, or the targeted lung
region can be one or more lung segments, such as, for example, the
lung segments described above with reference to FIGS. 2 and 3. In
the case of the targeted lung region being a lung lobe, an attempt
is made to bronchially isolate the target lobe by sealing the
direct pathways(s) into the target lobe, such as by implanting a
bronchial isolation device into the lobar bronchus that supplies
air to the targeted lobe. If the targeted lobe still does not
collapse, then it can be assumed that a collateral pathway is
supplying air to the targeted lobe, wherein the collateral pathway
is through an incomplete interlobar fissure. The outer surface of
the lung is covered with a serous membrane called the visceral
pleura. When the fissure between lobes is complete, the two
adjacent lobes are separated and are completely covered with
visceral pleura of all surfaces, and there is no collateral air
flow possible between lobes. When the fissure is incomplete, the
adjacent lobes are not completely separated, the visceral pleura
does not completely surround the lobes, and parenchyma from the
adjacent lobes in the incomplete portion of the fissure touch and
are not separated. This incomplete formation of the fissure occurs
naturally in about 50% of fissures in human lungs, and collateral
air flow can occur between the lobes through these regions. See,
Raasch B N, et al. Radiographic Anatomy of the Interlobar Fissure:
A Study of 100 Specimens. AJR 1982;138:1043-1049. When there is
collateral airflow through an incomplete interlobar fissure thereby
preventing collapse of the treated lobe, the lung can be treated to
cause the fissure to seal (either partially or entirely) and
thereby reduce or prevent collateral flow into the targeted lung
lobe via the interlobar fissure.
[0074] FIG. 5 shows an example of a lung lobe that has been
bronchially isolated using a bronchial isolation device comprised
of a flow control element, which regulates fluid flow through a
bronchial passageway that supplies fluid to the lobe. The lobe
receives collateral air flow through a collateral pathway comprised
of an incomplete interlobar fissure. As shown in FIG. 5, a
bronchial isolation device 510, such a flow control element, is
implanted in the right middle lobar bronchus 420 in order to
prevent direct flow into the targeted lung region comprised of the
right middle lobe 135. However, the right middle lobe 135 is still
receiving collateral flow (as exhibited by a series of arrows 512
in FIG. 5) through a collateral pathway comprised of an incomplete
right transverse fissure 128. The collateral flow comes from the
right upper lobar bronchus 417 and passes into the right middle
lobe 135 through the incomplete right transverse fissure 128. Thus,
the right upper lobar bronchus 417 can also be considered to be a
portion of the collateral pathway into the right middle lobe 135.
The collateral flow into the right middle lobe 135 could be
prevented or reduced by sealing the air pathways through the
incomplete right transverse fissure 128 where the middle lobe 135
contacts the inferior surface of the right upper lobe 130.
[0075] In another exemplary scenario, the targeted lung region can
be a specific lung segment or some other portion of the lung that
is within a lobe. In this case, an attempt is made to bronchially
isolate the targeted lung segment (or other portion of the lung),
such as by inserting a flow control element into the direct
pathway(s) to the targeted lung segment. If the targeted lung
segment still does not collapse, it can be assumed that the flow is
originating from other lung segments or other regions within the
same lobe as the targeted segment, or from an incomplete interlobar
fissure that is adjacent to the targeted lung segment. FIG. 6 shows
an example of this scenario. As shown in FIG. 6, a targeted lung
segment 610 is located within the right upper lobe 130. The
targeted lung segment 610 can receive direct flow via segmental
bronchus 615. The targeted lung segment 610 also receives
collateral flow from an adjacent segment 620 that is also located
within the right upper lobe 130.
[0076] In another example with reference to FIG. 6, a targeted lung
segment 630 is located in the right upper lobe 130 adjacent to the
right transverse fissure 128. The targeted lung segment 630 can
receive collateral flow from an adjacent lung segment in the right
upper lobe 130. The targeted lung segment 130 can also receive
collateral flow from the right middle lobe 135 via an incomplete
right transverse fissure 128, in which case a bronchial passageway
of the right middle lobe 135 is the source of the collateral
flow.
[0077] If collateral flow to a targeted lung segment is originating
from other segments or regions within the same lobe as the targeted
lung region, or is originating from a separate, adjacent lobe via
an incomplete fissure, it might be necessary to determine the
bronchial passageway that is supplying collateral flow to the
targeted lung region. One method of determining the magnitude of
collateral flow, using selective bronchial balloon catheterization
combined with ventilation on a helium-based marker gas and a helium
detector, is disclosed in the literature. See, Morrell N W, et al.
Collateral Ventilation and Gas Exchange in Emphysema, Am J Respir
Crit Care Med 1994;150:635-41.
[0078] One technique of identifying the bronchial passageway(s)
that feed the parenchyma that communicates through the incomplete
interlobar fissure with the targeted lung portion is now described.
According to this technique, the bronchial sub-branches, such as
segmental bronchi, feeding parenchyma adjacent to the interlobar
fissure of an isolated lobe are determined fluoroscopically
utilizing a standard guide wire. The following example illustrates
the technique as applied in the right upper lobe, although the same
principles could be used in any of the human lung's five lobes or
any segments within those lobes. Although the lung is 3-dimensional
and the airways are not sequentially related to linear lung regions
(e.g., the most inferior segmental bronchus may partially feed the
mid-section of a lung lobe or may preferentially feed the anterior
or posterior aspect of that lobe), the goal is to determine the
lowest (most inferior) sub-branch of the target upper lobe, as this
sub-branch provides airflow to the lung parenchyma that borders the
fissure between the upper lobe and the middle and lower lobes.
[0079] In a first step of the technique, a bronchoscope is passed
through the most inferior bronchus as seen from a bronchoscopic
perspective. This is performed according to well-known methods
using a standard bronchoscope. A guidewire is then passed through
the working channel of the bronchoscope and visually fed into the
subsequent, most inferior sub-branches to the visual limits of the
bronchoscope. The guidewire is then advanced further with the aid
of fluoroscopic visualization. For inferior/superior determination,
the fluoroscope will generally be in an anterior-posterior
orientation (90 degrees to the patient's chest). The position of
the guidewire relative to fluoroscopic landmarks (e.g.: relative to
a rib or to the diaphragm) is then noted. The aforementioned steps
are repeated in multiple sub-branches until it can be determined
which bronchial sub-branch feeds the most inferior lung tissue (and
thus adjacent to the interlobar fissure), and this sub-branch is
selected for treatment.
[0080] Utilizing a fully articulating C-arm (fluoroscope), these
steps can be repeated in other views (e.g. the camera in a 90
degree lateral view for anterior/posterior position) to map the
sub-branches in 3-dimensions. In this way, a physician can
determine which bronchial sub-branch or branches feed the most
inferior lung tissue, tissue that borders the right middle and
right lower lobes. This technique could be applied to any lobe in
the lung, and to either the inferior or superior surfaces.
Delivery of Flowable Therapeutic Agent to Targeted Lung Region
[0081] The flowable therapeutic agent can be delivered to the
targeted lung region according to a variety of methods. Some
exemplary methods of delivering a flowable therapeutic agent to the
targeted lung region are described below. Regardless of the method
used, the therapeutic agent can be delivered to the targeted lung
region either before or after an attempt is made to bronchially
isolate the targeted lung region using a bronchial isolation
device, or without bronchial isolation.
[0082] FIG. 7 illustrates an example of a method wherein a flowable
therapeutic agent 705 is delivered to a targeted lung region using
a delivery catheter 710. The targeted lung region is located in the
right middle lobe 135 of the right lung 110. The delivery catheter
710 can be a conventional delivery catheter of the type known to
those of skill in the art. The delivery catheter 710 is deployed in
a bronchial passageway, such as in the segmental bronchi 715, that
leads to the targeted lung region. The delivery catheter 710 is
deployed such that a distal end of the catheter 710 is positioned
distal of a bronchial isolation device 510 that has also been
deployed in the bronchial passageway 710. As mentioned, the
bronchial isolation device 510 can be deployed either before or
after deployment of the delivery catheter 710.
[0083] Once the delivery catheter 710 is deployed in the targeted
lung region, the flowable therapeutic agent 705 can be delivered
into the targeted lung region using the delivery catheter 710. This
can be accomplished by passing the flowable therapeutic agent
through an internal lumen in the delivery catheter so that the
agent exits a hole in the distal end of the delivery catheter 710
into the targeted lung region. As shown in FIG. 7, the distal end
of the delivery catheter 710 can be sealed within the targeted lung
region by inflating a balloon 720 that is disposed near the distal
end of the catheter according to well-known methods. In another
embodiment, shown in FIG. 8, the bronchial isolation device 510
provides the sealing so that a balloon is not needed when
delivering the flowable therapeutic agent 705 using the delivery
catheter 710.
[0084] FIG. 9 illustrates another method of delivering the flowable
therapeutic agent to the targeted lung region. According to the
method shown in FIG. 9, a delivery device, such as a delivery
catheter or a hypodermic needle 910, is used to percutaneously
inject the flowable therapeutic agent 705 directly into the lung
tissue of the targeted lung region. The hypodermic needle 910 is
used to puncture the chest wall according to well-known methods so
that a sharpened delivery tip 915 of the needle 910 locates within
the targeted lung region. For example, the targeted lung region
could comprise a portion of the right middle lobe 135 located near
the fissure 128, as shown in FIG. 9. The hypodermic needle 910 is
then used to puncture the chest wall and the needle 910 is
positioned so that the delivery tip 915 locates within the right
middle lobe 135. The flowable therapeutic agent 705 is then
injected directly into the targeted lung region via the hypodermic
needle 910 according to well-known methods.
[0085] FIG. 10 shows yet another method of delivering the flowable
therapeutic agent to the targeted lung region. According to this
method, a delivery catheter 710 has a distal tip 1005 that can be
used to puncture the wall of a bronchial passageway 1010 at a
location that is at or near the targeted lung region. The distal
tip 1005 is configured to facilitate puncturing of the bronchial
wall, as described more fully below. Once the distal tip 1005 has
been used to puncture the bronchial wall, the distal tip of the
delivery catheter 710 is passed through the bronchial wall and the
flowable therapeutic agent can be injected into the targeted lung
region through the delivery catheter 710. The method shown in FIG.
10 differs from the method described above with reference to FIGS.
7 and 8 in that the method shown in FIG. 10 actually punctures the
bronchial wall so that the flowable therapeutic agent can be
injected directly into the lung tissue. The method shown in FIGS. 7
and 8 does not include puncturing of the bronchial wall, and the
flowable therapeutic agent is injected into the bronchial lumen
leading to the targeted lung region rather than directly into the
lung tissue.
[0086] The puncturing of the bronchial wall can be accomplished
using any of a variety of methods and devices. According to one
embodiment, the distal tip 1010 of the delivery catheter is
configured to facilitate puncturing of the bronchial wall. For
example, the distal tip 1005 can be sharpened to an appropriate
sharpness that will facilitate puncturing of a bronchial wall. It
has been determined that a delivery catheter with a diameter of up
to 3 millimeters (mm) will be sufficient. Alternately, a hypodermic
needle can be mounted on the distal tip 1005 to facilitate
puncturing of the bronchial wall. In another configuration, a stiff
guidewire is delivered to the targeted lung region via the inner
lumen of a flexible bronchoscope. The guidewire is then used to
puncture the bronchial wall. After puncturing, a delivery catheter
is delivered over the stiff guidewire to the targeted lung region.
In another configuration radio frequency (RF) energy is applied to
a catheter that comprises an RF cutting tip, and the cutting tip is
applied to the bronchial wall at a location at or near the targeted
lung region, thereby causing the bronchial wall to puncture. A
device approved for this purpose is the Exhale RF Probe, Broncus
Technologies, Inc. Mountain View, Calif., FDA 510(k) #K011267. In
yet another configuration, a flexible biopsy forceps is delivered
through a working channel of the bronchoscope and used to cut a
hole through the bronchial wall in a well-known manner.
[0087] The delivery catheter 710 can be deployed at the targeted
lung region according to a variety of methods. For example, with
reference to FIG. 11, the delivery catheter 710 can be deployed
using a bronchoscope 1111, which in an exemplary embodiment has a
steering mechanism 1115, a delivery shaft 1120, a working channel
entry port 1125, and a visualization eyepiece 1130. The
bronchoscope 1111 has been passed into a patient's trachea 125 and
guided into the right primary bronchus 410 according to well-known
methods. The delivery catheter 710 is then deployed into the
working channel entry port 1125 and down a working channel (not
shown) of the bronchoscope shaft 1120, and the distal end 1135 of
the catheter 710 is guided to a desired location within the
bronchial tree, such as to a lobar bronchi 417 located within the
upper lobe 130 of the right lung 110. The steering mechanism 11 15
can be used to deliver the shaft 1120 to a desired location.
[0088] Alternately, the delivery catheter 710 can have a central
guidewire lumen and can be deployed using a guide wire that guides
the catheter to the delivery site. The delivery catheter 710 could
have a well-known steering function, which would allow the catheter
710 to be delivered with or without use of a guidewire.
[0089] In yet another method of delivering the flowable therapeutic
agent, one or more nasal cannulae are deployed through a patient's
nasal cavity, through the trachea, and to a desired location in the
bronchial tree 120 at the targeted lung region. One or more
bronchial isolation devices, such as a flow control element, can
also be deployed to bronchially isolate the targeted lung region,
with a distal end(s) of the cannula(e) being passed through the
bronchial isolation device(s). Alternately, a catheter with
multiple divided lumens or cannulae could be deployed. The cannula
can be left in place for a desired amount of time and an infusion
of one or more flowable therapeutic agents is deployed to the
targeted lung region via the cannula. The flowable therapeutic
agents could be continuously or intermittently administered at a
desired flow rate until the desired level of therapeutic effect has
been obtained. In another embodiment, the delivery catheter 710 can
be used to bronchially isolate the targeted lung region without the
use of, or in combination with the use of, a flow control element.
In such a case, the distal end of the delivery catheter 710 is
equipped with a balloon (such as the balloon 720 shown in FIG. 7),
which is inflated to occlude or partially occlude the bronchial
passageway that provides fluid flow to the targeted lung region. In
this manner, fluid flow through the bronchial passageway can be
reduced or eliminated.
Controlling Dispersion of the Therapeutic Agent in the Lung
[0090] In the course of delivering the therapeutic agent to the
targeted lung region, it can be desirable to control the dispersion
of the therapeutic agent in the lung so that the agent does not
flow through any collateral pathways into areas of healthy lung
tissue. It can also be desirable to move the therapeutic agent
preferentially toward the collateral pathway(s) (rather than toward
some other area of the lung) in order to increase the likelihood
that sealing of collateral pathway(s) is successful.
[0091] One way of controlling the movement of the therapeutic agent
within the lung is to provide pressure differentials in different
regions of the lung, wherein the pressure differentials encourage
the therapeutic agent to flow in a desired manner. For example, as
shown in FIG. 12, a targeted lung region 1210 is located in the
right lower lobe 140 of the right lung 110. A healthy lung region
1220 is located adjacent to the targeted lung region 1210. The
pressure within the targeted lung region is P1 and the pressure
within the adjacent lung region 1220 is P2. If P1 is greater than
P2, then a therapeutic agent located in the targeted lung region
1210 will be inclined to flow toward the adjacent lung region 1220
due to the pressure differential. Likewise, if P2 is greater P1,
then a therapeutic agent located in the targeted lung region 1210
will be inclined to flow away from the adjacent lung region
1220.
[0092] One way to accomplish such a pressure differential is to
control the injection pressure that is used to inject the
therapeutic agent into the targeted lung region, and to also
control a back pressure in an adjacent lung region where collateral
pathways to the targeted lung region originate. If the therapeutic
agent is radiopaque, a physician can view the extent of the
therapeutic agent dispersion while also varying the injection
pressure and the back pressure to control the dispersion.
[0093] This is described in more detail with reference to FIG. 13,
which shows a cross-sectional view of the right lung 110, wherein
the targeted lung region comprises the right middle lobe 135, which
is adjacent to a healthier lung region comprised of the right upper
lobe 130. The incomplete right transverse fissure 128 provides a
collateral pathway through which collateral flow originating in the
right upper lobe 130 passes into the right middle lobe 135. A first
delivery catheter 710, which can have a balloon 720, is passed
through a bronchial isolation device 510 so that the distal end of
the catheter 710 is disposed in the targeted lung region. A second
catheter 1305 is deployed in a bronchial passageway that provides
flow to a lung region adjacent to the target region, wherein some
collateral flow originates at the adjacent lung region. For
example, FIG. 13 shows the second catheter 1305 deployed through
the right lobar bronchus 417, which provides flow to the right
upper lobe 130 where the collateral flow into the right middle lobe
originates. The second catheter can have a balloon 1310 that is
inflated.
[0094] The delivery catheter 710 is then used to inject the
flowable therapeutic agent 705 into the targeted lung region at a
desired injection pressure. This will cause the targeted lung
region to achieve a pressure P1. While the therapeutic agent is
being injected, a suction can be applied to the distal end of the
second catheter 1305 to thereby achieve a pressure P2 in the
adjacent lung region comprised of the right upper lobe 130. By
controlling the injection pressure and suction, a desired pressure
differential between P1 and P2 can be achieved to thereby control
the dispersion of the therapeutic agent. The pressure differential
can be manipulated to encourage the therapeutic agent to flow
toward the collateral pathway and even enter the collateral
pathway. As discussed, the dispersion can be visually monitored if
the therapeutic agent includes a radiopaque.
[0095] When the desired dispersion level has been achieved, such as
when the therapeutic agent has filled the targeted lung region or
has filled the collateral pathways, it might then be desirable to
further control the dispersion to reduce the likelihood that the
therapeutic agent will flow into the healthy lung region. This can
be accomplished by again varying the pressure differential so that
the therapeutic agent no longer flows towards the healthy lung
region. For example, the injection pressure can be reduced or
eliminated, while also changing the suction pressure at the second
catheter 1305. Suction can then be applied to the delivery catheter
710 to remove any excess therapeutic agent from the targeted lung
region. The catheters 710,1305 are then removed. In this manner,
the therapeutic agent is preferentially moved toward the collateral
pathway(s).
[0096] The aforementioned technique for sealing the collateral flow
pathway could also be performed prior to the implantation of the
bronchial isolation device(s) 510.
Follow-On Therapy After Treatment with Flowable Therapeutic
Agent
[0097] After the infusion of the flowable therapeutic agents into
the targeted lung region, a follow-on therapy procedure can be
followed. According to one procedure, the treated portion of the
lung (the portion of the lung to which the therapeutic agent was
applied) is left alone, with the therapeutic agent in place. The
treated lung portion is allowed to collapse by either absorption of
the therapeutic agent by the body, absorption of the trapped gas in
the isolated lung region, exhalation of trapped gas out through a
flow control device (such as an implanted one-way or two-way valve
device) or any combination of these events.
[0098] According to another follow-on therapy procedure, the
therapeutic agent is removed from the lung following the passage of
a predetermined treatment period. The therapeutic agent could be
removed after a short period of time such as one or two minutes, or
a longer period of 30 or 60 minutes. Alternatively, if required,
the therapeutic agent could be removed in a separate procedure
hours or days later. The necessary time period would depend on the
particular therapeutic agent used. This could be done with the
implanted bronchial isolation devices in place, or could be done
before implantation of the bronchial isolation devices if the
therapeutic agent was deployed prior to implantation of the
bronchial isolation devices. The therapeutic agent can be removed
from the lung in any number of ways, which include the following:
[0099] (a) Inflating a balloon catheter in the bronchial passageway
leading to the targeted lung region and aspirating through the
catheter central lumen. If bronchial isolation devices had been
implanted already, the suction in the catheter would pull the
excess therapeutic agent through the one-way or two-way valves of
the isolation devices. This method is likely not used where the
implanted devices are plugs or occluders. [0100] (b) Crossing the
implanted one-way or two-way valves with a catheter and applying
suction through the central lumen of the catheter. The catheter
could either be sealed by the valve in the implanted device, or it
could be a balloon catheter where the balloon is inflated in the
bronchial passageway distal to the implanted device. [0101] (c)
Percutaneously suctioning the therapeutic agent directly out of the
lung tissue, such as by using a hypodermic needle. [0102] (d)
Suctioning the therapeutic agent out of the targeted lung region
through the a hole created in the bronchial wall. This can be done
using a new catheter or using the same catheter as was used to
inject the agent.
[0103] Thus, there have been disclosed several basic approaches to
injecting a flowable therapeutic agent for preventing or reducing
collateral flow into a targeted lung region. Some examples of the
basic approaches are summarized as follows: [0104] (a) Implant one
or more bronchial isolation devices to isolate targeted lung
region; inject a flowable therapeutic agent into the targeted lung
region distal to the bronchial isolation devices; allow the lung
region to collapse, such as, for example, by absorption of the
therapeutic agent by the body, absorption of the trapped gas in the
isolated lung portion, exhalation of trapped gas out through the
implanted one-way or two-way valve devices, or any combination of
these events. [0105] (b) Implant one or more bronchial isolation
devices; inject a flowable therapeutic agent into the targeted lung
region distal to devices;
[0106] wait a pre-determined treatment time period; remove the
therapeutic agent, such as, for example, by using suction, needle
aspiration, etc.; and
[0107] allow the lung region to collapse, such as, for example, by
absorption of the trapped gas in the isolated lung portion,
exhalation of trapped gas out through the implanted one-way or
two-way valve devices, or both. [0108] (c) Inject a flowable
therapeutic agent into the targeted lung region;
[0109] implant bronchial isolation devices; allow the targeted lung
region to collapse, such as, for example, by absorption of the
therapeutic agent by the body, absorption of the trapped gas in the
isolated lung portion, exhalation of trapped gas out through the
implanted one-way or two-way valve devices, or any combination of
these events. [0110] (d) Inject a flowable a therapeutic agent into
parenchyma of the targeted lung region; implant one or more
bronchial isolation devices; wait a pre-determined treatment time
period; remove the therapeutic agent, such as, for example, using
suction, needle aspiration, etc.; and allow lung region to
collapse, such as, for example, by absorption of the trapped gas in
the isolated lung portion, exhalation of trapped gas out through
the implanted one-way or two-way valve devices, or both. [0111] (e)
Inject a flowable therapeutic agent into the targeted lung region;
wait a pre-determined treatment time period; remove therapeutic
agent; implant bronchial isolation devices; and allow the lung
region to collapse. [0112] (f) Temporarily isolate the targeted
lung region; inject a flowable therapeutic agent into the targeted
lung region; wait a pre-determined treatment time period; and
remove therapeutic agent. [0113] (g) Temporarily isolate the
targeted lung region; and inject a flowable therapeutic agent into
the targeted lung region. Application of Energy to Reduce or
Prevent Collateral Flow
[0114] An alternate way of reducing or preventing collateral fluid
flow into the targeted lung region is to apply energy to the
targeted lung region, wherein the application of energy generates a
reaction in the tissue of the targeted lung region that serves to
reduce or prevent collateral fluid flow into the targeted lung
region. The reaction can result in, for example: (1) gluing or
sealing portions of the lung together to thereby partially or
entirely seal collateral pathways; (2) sclerosing or scarring
target lung tissue to thereby partially or entirely occlude the
collateral pathway(s) and partially or entirely seal off collateral
flow into the targeted lung region; (3) promoting fibrosis in or
around the targeted lung region to thereby partially or entirely
seal off collateral flow into the region; (4) creating of an
inflammatory response that would partially or entirely seal or fuse
collateral pathway(s) that lead into the targeted lung region. A
variety of energy sources have been identified that can be used to
apply energy to lung tissue to achieve any of the aforementioned
reactions. The types of energy include Beta-emitting radiation,
radio frequency energy, heat, ultrasound, cryo-ablation, laser
energy, and electrical energy. The process of identifying the lung
region for treatment can be the same as that described above with
reference to the use of the flowable therapeutic agent.
[0115] A variety of different methods can be used to deliver energy
to a desired location in the targeted lung region. Regardless of
the method used, the therapeutic agent can be delivered to the
targeted lung region either without bronchial isolation, or before
or after an attempt is made to bronchially isolate the targeted
lung region using a bronchial isolation device.
[0116] FIG. 14 illustrates a method wherein an energy source is
delivered to a targeted lung region using a delivery catheter 710.
The targeted lung region is located in the right middle lobe 135 of
the right lung 110. The delivery catheter 710 can be a conventional
delivery catheter of the type known to those of skill in the art.
The delivery catheter 710 is deployed in a bronchial passageway,
such as in the sub-segmental bronchi 715, that leads to the
targeted lung region. A distal end of the catheter 710 is inserted
into the bronchial passageway and is positioned distal of a
bronchial isolation device 510 that has been deployed in a
bronchial passageway that provides direct flow to the targeted lung
region. As discussed above, the bronchial isolation device 510 can
be deployed either before or after deployment of the delivery
catheter 710.
[0117] Once the delivery catheter 710 is deployed in the targeted
lung region, an energy source 1410 can be delivered into the
targeted lung region using the delivery catheter 710. This can be
accomplished, for example, by passing a push wire 1415 having a
distally-mounted energy source 1410 through an internal lumen in
the delivery catheter 710 so that the energy source 1410 exits a
hole in the distal end of the delivery catheter 710 into the
targeted lung region. Alternately, the energy source 1410 can be
mounted on the distal end of the delivery catheter 710. The distal
end of the delivery catheter 710 can be sealed within the targeted
lung region by inflating a balloon that is disposed near the distal
end of the catheter according to well-known methods. Alternately,
the bronchial isolation device 510 can provide the sealing so that
a balloon is not needed.
[0118] According to another method of delivering the energy, a
delivery device, such as delivery catheter or a hypodermic needle,
is used to percutaneously reach the targeted lung region by
puncturing the chest wall and outer surface of the lung. The energy
source is then advanced directly into the lung tissue. This would
be similar to the method shown in FIG. 9, although an energy source
would be used in place of the flowable therapeutic agent.
[0119] In yet another method of delivering the energy to the
targeted lung region, a delivery catheter has a distal tip that can
be used to puncture the wall of a bronchial passageway that is
located at or near the targeted lung region. The distal tip is
configured to facilitate puncturing of the bronchial wall. Once the
distal tip's-has been used to puncture the bronchial wall, the
energy source is advanced into the targeted lung region through the
delivery catheter. This would be similar to the process shown in
FIG. 10. The puncturing of the bronchial wall can be accomplished
using any of a variety of methods and devices, such as was
described above with reference to FIG. 10.
[0120] The delivery catheter for delivering the energy source to
the targeted lung region could be deployed in the same manner
described above with reference to the flowable therapeutic agents,
such as by using a bronchoscope.
Exemplary Method for Applying Energy to Targeted Lung Region
[0121] The delivery of beta-emitting radiation could be
accomplished with a brachytherapy delivery system that includes a
beta-emitting radiation source mounted to the end of a delivery
catheter, such as was described above. As mentioned previously,
this could be done either before or after the implantation of
bronchial isolation devices.
[0122] According to one method of applying the energy, a beta
radiation-emitting source is passed through one or more target
bronchial passageways, either sequentially or concurrently, that
lead to the targeted lung region. The source can also be passed
through one or more of the bronchial isolation devices that were
previously implanted. The radiation source is left in place for a
period of time so as to elicit a scarring/healing response in the
treated lung tissue. For example, it may be discovered through
animal and/or human clinical trials that an exposure time period of
30 minutes to one hour will achieve satisfactory results. A maximum
time may be identified wherein the risk of radiation to the
surrounding tissue is greater than the benefits of scarring the
target tissue. For example, it may be discovered that the radiation
source can remain in up to an hour, but that exposure for greater
than 90 minutes increases risk to the patient.
[0123] In another application method, the application procedure is
performed over a predetermined time period and/or over bronchial
sub-branches. For example, a patient can first be admitted for a
procedure to deploy bronchial isolation devices, such as flow
limiting valves, and then discharged with periodic reassessment of
anatomical or clinical results. The physician and patient could
decide when the next step of transvalvular brachytherapy should
take place (e.g.: 15-30 days after the primary procedure).
Brachytherapy could also be staged over time in such a way as to
minimize risk while continually assessing benefit (e.g.: valves
placed day one, first brachytherapy procedure of 30 minutes
exposure day 30, second brachytherapy procedure of 30 minutes at
day 60, etc.). The first brachytherapy session could be targeted at
the RUL, inferior sub-segment of the anterior, segmental bronchus;
the second session would target the RUL superior sub-segment of the
anterior, segmental bronchus; etc.
[0124] The same procedures described above for beta-emitting
radiation could be followed for other radiation sources such as RF
energy, heat, ultrasound, or cryo-ablation. These energy sources
might require different treatment times, a different number of
treatment sites, etc., but the general application method would be
the same.
Use of Flow-Limiting Isolation Devices to Limit Collateral Flow
[0125] Another way of impeding collateral fluid flow into the
targeted lung region is now described, wherein flow-limiting
devices are implanted in the bronchial passageway leading to lung
regions adjacent to the target region, wherein the adjacent lung
region that is not targeted for collapse.
[0126] As with the previously described methods, the lung region
targeted for isolation and collapse is identified, and bronchial
isolation devices are implanted in all airways that provide direct
flow to the targeted lung region. The implanted isolation devices
can be, for example, one-way valves that allow flow in the
exhalation direction only, one-way valves that allow flow in the
inhalation direction only, occluders or plugs that prevent flow in
either direction, or two-way valves that control flow in both
directions according to well-known methods. If the lung region does
not collapse, such as due to either absorption atelectasis, or
through exhalation of trapped gas through the implanted devices,
then the lung region is likely being kept inflated through
collateral in-flow through collateral pathways from adjacent lung
regions. If the collateral flow from-the adjacent lung regions
could be reduced substantially or eliminated, the targeted lung
region will likely collapse.
[0127] One way to reduce or substantially eliminate the collateral
flow from adjacent lung regions is to implant inhalation flow
limiting two-way valve devices in the bronchial passageways leading
to adjacent lung regions not targeted for collapse, wherein the
adjacent lung regions act as a source for collateral flow into the
targeted lung region. Such devices would allow free fluid flow in
the exhalation direction for the adjacent lung regions, but would
limit the flow to a predetermined level in the inhalation
direction. As a result, flow into the adjacent lung region would be
limited, thereby limiting the flow of gas into the targeted lung
region through the collateral pathways from the adjacent lung
regions. The flow limitation is desirably sufficient to allow the
isolated lung region to collapse, but would not collapse the
adjacent lung regions. Once sufficient time had passed to allow the
targeted lung region to become chronically atelectatic, the flow
limiting two-way valve devices could be removed from the adjacent
lung regions in order to restore normal ventilation to the lung
portion not targeted for collapse.
[0128] An example of this method is shown in FIG. 15, which shows a
targeted lung region comprised of the right upper lobe 130 that is
isolated by one-way bronchial isolation devices 510 that are
implanted in all bronchial passageways leading to the lobe 130. The
devices 510 are one-way valve devices that stop all flow in the
inhalation direction to thereby prevent direct flow into the lobe
130. A flow limiting two-way valve bronchial isolation device 1510
is implanted in the bronchial passageway in the right middle lobe
135 in the segment that lies just below the interlobar fissure 128
adjacent to the lobe 130. The device 1510 allows free flow in the
exhalation direction and a limited flow in the inhalation
direction. This limits the flow into the middle lobe 135, in a
manner determined by the back flow restriction of the two-way
valve. By limiting the flow into the middle lobe 135, the
collateral flow into the targeted upper lobe 130 that originates in
the middle lobe 130 is also limited. The flow limitation into the
middle lobe 135 is sufficient to allow the right upper lobe 130 to
collapse, as the collateral flow into the upper lobe 135 via the
fissure 128 is insufficient to inflate the upper lobe 130.
[0129] One exemplary embodiment of a flow limiting two-way valve
2500 is shown in FIGS. 22-25. In this embodiment, the valve would
behave as a one-way valve in the forward or exhalation direction in
that it would allow free flow of fluid through the valve. However,
the valve would also allow a controlled rate of flow in the reverse
or inhalation direction. This could be achieved in a duckbill style
valve by adding a small flow channel 2510 through the lips 2512 of
the valve, as shown in FIG. 25. The reverse flow channel shown
would allow fluid to flow in the inhalation direction, and the rate
of flow would be controlled by diameter and length of the flow
channel.
Use of Percutaneous Suction to Limit Collateral Flow
[0130] Another method for limiting collateral flow into a targeted
lung region is through the use of percutaneous suction. As
discussed, bronchial isolation devices may be implanted in any
bronchial passageways that provide direct flow to the targeted lung
region. Percutaneous suction is then applied to the targeted lung
region for a time period sufficient to adhere or fuse the lung
tissue in the targeted lung region in a collapsed state such that
the targeted lung region will not re-inflate through collateral
pathways after the suction is stopped.
[0131] The percutaneous suction method is described in more detail
with reference to FIG. 16, which shows the targeted lung region
being located in the right upper lobe 130. An attempt is made to
bronchially isolate the targeted lung region by implanting one or
more bronchial isolation devices 705 in bronchial passageway that
provide direct flow into the targeted lung region. A suction
catheter 1610 is percutaneously inserted into the targeted lung
region, such as by inserting the catheter 705 through the rib space
in a well-known manner. The suction catheter 1610 includes an
internal lumen and has a distal end 1615 on which are located one
or more suction holes 1620 that communicate with the internal
lumen. A suction force can be applied to a proximal end 1625 of the
catheter 1610 to suck fluid into the internal lumen through the
suction holes 1620 on the distal end 1615 of the catheter 1610. A
fixation balloon 1630 is mounted on the catheter 1610 a short
distance from the distal end 1615 of the catheter 1610. In one
embodiment, the fixation balloon 1630 is mounted approximately 2
centimeters from the distal end 1615. An exemplary suction catheter
that can be used is the 8-French Venography Catheter, manufactured
by The Cook Group, Inc., Bloomington, Ind.
[0132] As shown in FIG. 16, the suction catheter 1610 is
percutaneously inserted into the targeted lung region so that the
suction holes 1620 in the distal end 1615 are positioned within the
targeted lung region. The fixation balloon 1630 is positioned in
the pleural space of the lung and is then inflated to thereby fix
the suction catheter 1610 in a fixed position and to also seal the
incision that was used to percutaneously insert the catheter 1610.
The suction catheter 1610 can be maneuvered into the correct
location using guidance assistance, such as computer tomography
(CT) or fluoroscopic guidance.
[0133] After the suction catheter 1610 has been properly
positioned, a suction force can be applied to the internal lumen of
the catheter to thereby cause a sucking force that draws fluid into
the internal lumen through the suction holes 1620. The suction
force will draw air or other fluid in the targeted lung region into
the internal lumen through the suction holes 1620, which will
aspirate the targeted lung region into a collapsed state. It has
been determined that a suction force of approximately 100-160 mmHg
is sufficient to aspirate the targeted lung region into a collapsed
state. The suction force can be continuously maintained for a time
period sufficient to permanently collapse the lung and reduce the
likelihood of inflation through collateral pathways. In one
embodiment, the suction is continuously maintained for a minimum
time period of eight hours. In another embodiment, the suction is
maintained for a time period of one to eight days. The suction can
be performed while the patient is on bed rest, using a stationary
vacuum source, or it could be performed using a portable vacuum
source in order to permit the patient to ambulate.
[0134] After the suction time period has elapsed, a flowable
therapeutic agent (such as any of the agents described above) can
optionally be infused into the targeted lung region. This could be
performed using the suction catheter 1610, such as by infusing the
agent through a separate internal lumen located in the catheter
1610 or through the same lumen that was used for suction. The
therapeutic agent could be used to increase the likelihood that the
targeted lung region is properly sealed. The fixation balloon 1630
is then deflated and the suction catheter 1610 is removed.
Use of Two-Part Adhesive to Limit Collateral Flow
[0135] According to another method of inhibiting collateral flow
into a targeted lung region, a two-part adhesive or glue is used to
occlude a collateral pathway to the targeted lung region. The
adhesive can comprise a two-part mixture that includes a first part
and a second part, wherein the first part and the second part
collectively solidify when brought into contact with each other.
The two parts do not necessarily require complete mixing in order
for the solidification to occur. The solidification can be
triggered, for example, by a catalytic reaction that occurs when
the two parts contact one another. In one embodiment, the two-part
glue is a fibrin glue and the two parts of the glue are thrombin
and fibrinogen.
[0136] A method for deploying a two-part adhesive in order to seal
a collateral pathway is now described. The collateral pathway is
located in a lung region between two or more bronchial passageway,
such as a first bronchial passageway and a second bronchial
passageway. For example, as shown in FIG. 17, the collateral
pathway can be an incomplete interlobar 128 fissure that is located
between a first bronchial passageway 1710 and a second bronchial
passageway 1715. The bronchial passageway are not necessarily in
the same lobe. For example, in FIG. 17 the bronchial passageway
1710 is in the right upper lobe 130 and the bronchial passageway
1715 is in the right middle lobe 135, where the targeted lung
region is also located.
[0137] According to the method, the first part of the two-part
adhesive is injected into the first bronchial passageway and the
second part of the two-part adhesive is injected into the second
bronchial passageway. The injection pressure and flow rates of the
first and second parts can be controlled to encourage the first and
second parts to flow to a common location, wherein the common
location coincides with the location of the collateral flow path.
That is, the first and second parts will contact one another within
the collateral flow path. As mentioned, the first and second parts
solidify when they contact one another. In this manner, the first
and second parts solidify within the collateral flow path and
thereby partially or entirely seal the collateral flow path.
[0138] An example of this is shown in FIG. 17, which shows a
balloon-tipped catheter 1712 that has been deployed in the second
bronchial passageway 1715, which supplies direct flow to the
targeted lung region. A bronchial isolation device 510 is deployed
in a segmental bronchus 1735 that is proximal to the second
bronchial passageway 1715 in order to bronchially isolate the
targeted lung region. The catheter 1712 is sealed within the
bronchial passageway 1715 by inflating a balloon 1720 mounted on
the catheter 1712. A second balloon-tipped catheter 1725 is
deployed in the first bronchial passageway 1710 and sealed by
inflating a balloon 1730. The first part 1728 of the two-part
adhesive is then injected into the bronchial passageway 1715 via
the catheter 1712 and the second part 1732 of the two-part adhesive
is injected into the bronchial passageway 1710 via the catheter
1725. The first and second parts are injected in such a manner that
they flow into the lung and meet at the collateral pathway
comprised of the incomplete interlobar fissure 128. As a result of
the contact between the first and second parts, they solidify
within the interlobar fissure and thereby partially or entirely
seal the interlobar fissure.
[0139] Once the adhesive has solidified, any remaining quantity of
the first and second parts can be suctioned out of the lung.
Alternately, the first and second parts could be absorbable by the
body so that excess material need not be removed. The
aforementioned technique for sealing the collateral flow pathway
could also be performed prior to the implantation of the bronchial
isolation device(s) 510.
Implanted Shunt Tubes
[0140] One of the major challenges with emphysematic patients is
that certain bronchial passageways collapse during exhalation, thus
leading to reduced flow through these lumens. This often results in
trapped gas in certain regions of the lung that exhale air through
the collapsed lumen. This in turn can lead to hyperinflation of the
lung region, as well as compression of the healthy lung tissue that
is adjacent to the lung region. One way of treating the
hyperinflated lung region is to implant bronchial isolation
devices, such as one-way or two-way valves, in the bronchial
passageway that lead to the lung region in order to promote lung
region collapse. However, the effectiveness of the bronchial
isolation devices can be limited due to the reduced air flow during
exhalation through the native bronchial passageways, especially if
collateral flow is present.
[0141] One method of counteracting this effect is to implant one or
more shunt tubes that are inserted through the bronchial
passageways and into the targeted lung region comprised of a
damaged lung region. The shunt tubes provide a clear flow path for
exhaled air that is not be occluded by the collapsed bronchial
passageway. In order to collapse the targeted lung region, one-way
valves may be either mounted to a proximal end of the shunt tubes,
or implanted in the bronchial passageways at some distance proximal
to the proximal end of the tubes. These valves allow exhaled air to
escape in the exhalation direction through the valve or valves, but
do not allow inhaled air to return to the isolated targeted lung
region. In this way, the targeted lung region eventually collapses
after sufficient air had been exhaled. Alternatively, a self
expanding braided tube can be used to prop the collapsed airway
open. This allows side branches to continue to exhale air into the
braided tube while keeping the bronchi open.
[0142] FIG. 18 shows an example of how shunt tubes can be utilized.
A bronchial isolation device 510 is implanted in a bronchial
passageway of the right upper lobe 130. Two implanted shunt tubes
1810 and 1820 are shown deployed in two lumens. The shunt tubes
1810, 1820 are located distal to the implanted isolation device
510. The shunt tubes 1810, 1820 keep the airways open and provide a
flow path through which exhaled air can pass. The implanted shunt
tubes 1810 and 1820 are shown in FIG. 18 as being implanted just
distally to the implanted bronchial isolation device 510.
Alternatively, the shunt tubes may be implanted more distally, and
a greater quantity may be implanted. The shunt tubes may be
anchored in the bronchial lumen in a number of ways. In a first
embodiment, the shunt tube have spring resilience and expand when
released from a smaller constrained diameter to a larger diameter,
thus gripping the bronchial lumen wall. Alternately, the shunt
tubes may comprise a deformable retainer that is expanded to grip
the bronchial lumen wall by inflating a balloon placed inside the
collapsed shunt tube. The shunt tubes may also comprise a
cylindrical structure that increases in diameter when its
temperature is raised to body temperature. The shunt tubes may also
have barbs, prongs or other features on the outside that assist in
gripping the bronchial lumen wall for retention.
Exemplary Bronchial Isolation Devices
[0143] As discussed above, a target lung region can be bronchially
isolated by advancing a bronchial isolation device into the one or
more bronchial pathways that directly feed air to the targeted lung
region. The bronchial isolation device can be a device that
regulates the flow of fluid into or out of a lung region through a
bronchial passageway. FIG. 19 shows a cross-sectional view of an
exemplary bronchial isolation device comprised of a flow control
element 1910. It should be appreciated that the flow control
element 1910 is merely an exemplary bronchial isolation device and
that other types of bronchial isolation devices for regulating air
flow can also be used. For example, the following references
describe exemplary bronchial isolation devices: U.S. Pat. No.
5,594,766 entitled "Body Fluid Flow Control Device; U.S. patent
application Ser. No. 09/797,910, entitled "Methods and Devices for
Use in Performing Pulmonary Procedures"; and U.S. patent
application Ser. No. 10/270,792, entitled "Bronchial Flow Control
Devices and Methods of Use". The foregoing references are all
incorporated by reference in their entirety and are all assigned to
Emphasys Medical, Inc., the assignee of the instant
application.
[0144] With reference to FIG. 19, the flow control element 1910 is
in the form of a valve with a valve member 1915 supported by a ring
1920. The valve member 1915 is a duckbill-type valve and has two
flaps defining an opening 1925. The valve member 1915 is shown in a
flow-preventing orientation in FIG. 19 with the opening 1925
closed. The valve member 1915 is configured to allow free fluid
flow in a first direction (along arrow A) while controlling fluid
flow in a second direction (along arrow B). In the illustrated
embodiment, fluid flow in the direction of arrow B is controlled by
being completely blocked by valve member 1915. The first and second
directions in which fluid flow is allowed and controlled,
respectively, can be opposite or substantially opposite each other,
such as is shown in FIG. 19. The valve member 1915 functions as a
one-way valve by completely blocking fluid flow in a certain
direction. It should be appreciated that the flow control element
could be configured to block or regulate flow along
two-directions.
[0145] FIGS. 20 and 21 show another embodiment of an exemplary flow
control element, comprising flow control element 2000. The flow
control element 2000 includes a main body that defines an interior
lumen 2010 through which fluid can flow along a flow path. The flow
of fluid through the interior lumen 2010 is controlled by a valve
member 2012. The valve member 2112 in FIGS. 20-21 is a one-way
valve, although two-way valves can also be used, depending on the
type of flow regulation desired. FIGS. 22-25 show an exemplary
two-way valve member 2500.
[0146] With reference again to FIGS. 20-21, the flow control
element 2010 has a general outer shape and contour that permits the
flow control device 2010 to fit entirely within a body passageway,
such as within a bronchial passageway. The flow control member 2000
includes an outer seal member 2015 that provides a seal with the
internal walls of a body passageway when the flow control device is
implanted into the body passageway. The seal member 2015 includes a
series of radially-extending, circular flanges 2020 that surround
the outer circumference of the flow control device 2000. The flow
control device 2000 also includes an anchor member 2018 that
functions to anchor the flow control device 2000 within a body
passageway. It should be appreciated that other types of flow
control devices can also be used to bronchially isolate the
targeted lung region.
[0147] The flow control element can be implanted in the bronchial
passageway using a delivery catheter. According to this process,
the flow control element is mounted on a distal end of the delivery
catheter. The distal end of the delivery catheter is then deployed
to the bronchial passageway, such as by inserting the delivery
catheter through the patient's mouth or nose, through the trachea,
and through the bronchial tree to the desired location in the
bronchial passageway. The delivery catheter can be deployed, for
example, using a guide wire or without a guide wire. In one
embodiment, a bronchoscope is deployed to the location in the
bronchial passageway where the flow control device will be
deployed. The delivery catheter with the flow control element is
then deployed to the bronchial passageway by inserting the delivery
catheter through a working channel of the bronchoscope such that
the distal end of the delivery catheter and the attached flow
control element protrude from the distal end of the working channel
into the bronchial passageway. The flow control element is then
removed from the delivery catheter so that the flow control
elements is positioned within and retained in the bronchial
passageway. U.S. patent application Ser. No. 10/270,792, entitled
"Bronchial Flow Control Devices and Methods of Use" (which is
assigned to Emphasys Medical, Inc., the assignee of the instant
application) describes various methods and devices for implanting a
flow control element into a bronchial passageway.
[0148] Although embodiments of various methods and devices are
described herein in detail with reference to certain versions, it
should be appreciated that other versions, embodiments, methods of
use, and combinations thereof are also possible. Therefore the
spirit and scope of the appended claims should not be limited to
the description of the embodiments contained herein.
* * * * *