U.S. patent application number 12/493677 was filed with the patent office on 2009-10-22 for methods, systems and devices for improving ventilation in a lung area.
This patent application is currently assigned to Breathe Technologies, Inc.. Invention is credited to Anthony D. Wondka.
Application Number | 20090260625 12/493677 |
Document ID | / |
Family ID | 33567592 |
Filed Date | 2009-10-22 |
United States Patent
Application |
20090260625 |
Kind Code |
A1 |
Wondka; Anthony D. |
October 22, 2009 |
METHODS, SYSTEMS AND DEVICES FOR IMPROVING VENTILATION IN A LUNG
AREA
Abstract
Methods, systems and devices are described for new modes of
ventilation in which specific lung areas are ventilated with an
indwelling trans-tracheobronchial catheter for the purpose of
improving ventilation and reducing hyperinflation in that specific
lung area, and for redistributing inspired air to other healthier
lung areas, for treating respiratory disorders such as COPD, ARDS,
SARS, CF, and TB. Trans-Tracheobronchial Segmental Ventilation
(TTSV) is performed on either a naturally breathing or a mechanical
ventilated patient by placing a uniquely configured indwelling
catheter into a bronchus of a poorly ventilated specific lung area
and providing direct ventilation to that area. The catheter can be
left in place for extended periods without clinician attendance or
vigilance. Ventilation includes delivery of respiratory gases,
therapeutic gases or agents and evacuation of stagnant gases, mixed
gases or waste fluids. Typically the catheter's distal tip is
anchored without occluding the bronchus but optionally may
intermittently or continuously occlude the bronchus. TTSV is
optionally performed by insufflation only of the area, or by
application of vacuum to the area, can include elevating or
reducing the pressure in the targeted area to facilitate stagnant
gas removal, or can include blocking the area to divert inspired
gas to better functioning areas.
Inventors: |
Wondka; Anthony D.;
(Thousand Oaks, CA) |
Correspondence
Address: |
PATTON BOGGS LLP
8484 WESTPARK DRIVE, SUITE 900
MCLEAN
VA
22102
US
|
Assignee: |
Breathe Technologies, Inc.
San Ramon
CA
|
Family ID: |
33567592 |
Appl. No.: |
12/493677 |
Filed: |
June 29, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10870849 |
Jun 17, 2004 |
|
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12493677 |
|
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60479213 |
Jun 18, 2003 |
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Current U.S.
Class: |
128/203.12 ;
128/204.18; 128/205.25 |
Current CPC
Class: |
A61M 16/0012 20140204;
A61M 16/0404 20140204; A61M 2205/8225 20130101; A61M 16/042
20140204; A61M 16/0465 20130101; A61M 16/0434 20130101; A61M
16/0445 20140204; A61M 2209/06 20130101; A61M 2016/103 20130101;
A61M 16/10 20130101; A61M 2016/0021 20130101; A61M 16/0459
20140204; A61M 16/04 20130101; A61M 16/0672 20140204; A61M 2230/432
20130101; A61M 16/0009 20140204; A61M 16/0486 20140204 |
Class at
Publication: |
128/203.12 ;
128/204.18; 128/205.25 |
International
Class: |
A61M 16/00 20060101
A61M016/00; A61M 16/10 20060101 A61M016/10; A61M 16/06 20060101
A61M016/06 |
Claims
1. A method for directly ventilating a compartment of a lung via a
continuously indwelling catheter placed in the bronchial tree,
wherein said catheter has a distal end and a proximal end, wherein
said distal end is anchored in the bronchus of said lung
compartment, and wherein said proximal end is connected to an
ventilation source external to the patient, and wherein said
catheter can remain in place for extended periods without clinician
vigilance and wherein said ventilation source includes a gas
removal means and a gas delivery means and wherein said ventilating
includes gas delivery and gas removal.
2. A method for directly ventilating a compartment of a lung via a
continuously indwelling catheter placed in the bronchial tree,
wherein said catheter has a distal end and a proximal end, wherein
said distal end is anchored in the bronchus of said lung
compartment, and wherein said proximal end is connected to an
ventilation source external to the patient, and wherein said
catheter can remain in place for extended periods without
vigilance.
3. A method as in claim 2 wherein said ventilation comprises gas
delivery and gas removal.
4. A method as in claim 2 wherein said ventilation comprises
applying vacuum to said area wherein said vacuum level is
continuous, intermittent, oscillatory at high, medium or low
frequencies, synchronized with the patient's breathing, or
asynchronous with said patient's breathing.
5. A method as in claim 2 wherein said ventilation comprises gas
delivery wherein said delivery is continuous, intermittent,
oscillatory at high, medium or low frequencies, synchronized with
the patient's breathing, or asynchronous with said patient's
breathing.
6. A method as in claim 2 wherein said ventilation comprises a gas
delivery phase and a gas removal phase wherein said phases
alternate.
7. A method as in claim 2 wherein said ventilation comprises a gas
delivery phase and a gas removal phase wherein said phases
alternate at a rate of one to sixty cycles per minute.
8. A method as in claim 2 wherein said ventilation comprises a gas
delivery phase and a gas removal phase wherein said phases
alternate and are synchronized with the breath cycle, such as but
not limited to gas delivery during inspiration and gas removal
during exhalation.
9. A method as in claim 2 wherein said ventilation comprises a gas
delivery phase and a gas removal phase wherein said two phases
occur simultaneously.
10. A method as in claim 2 wherein said ventilation comprises gas
delivery and gas removal and wherein the parameters of said
delivery and removal are controlled so that the residual volume in
said lung area decreases, typically by removing more gas during
said gas removal phase compared to gas delivered during said
delivery phase.
11. A method as in claim 2 wherein said ventilation comprises the
delivery of a ventilation gas and wherein the parameters of said
ventilation are regulated to obtain a predominant concentration of
said ventilation gas in said target area.
12. A method as in claim 2 wherein said ventilation comprises the
delivery of a ventilation gas and wherein delivery is regulated to
create an elevated pressure in said area for the purpose of
facilitating displacement of stagnant native gas, mixed gases and
waste gases from said area, such as displacement via the blood
absorption, displacement through collateral channels, displacement
proximally up the bronchial tree, or displacement through said
catheter.
13. A method as in claim 2 wherein said ventilation comprises gas
delivery and gas removal wherein the pressure in said targeted area
is regulated by measuring said pressure and adjusting said gas
delivery and or said gas removal to achieve a desired said
pressure.
14. A method as in claim 2 wherein said ventilation comprises gas
delivery and gas removal wherein a gas concentration in said area
is measured to determine the completeness of native gas replacement
from said area, or to determine and adjust the parameters of said
ventilation to optimize the therapy, such as but not limited to
measuring the CO.sub.2 or O2 concentration of said removed gas.
15. A method as in claim 2 wherein said ventilation comprises
positive pressure gas delivery and application of vacuum, wherein
said pressure is typically in the range of 5-25 cmH2O and 20-50
cmH2O during natural breathing and mechanical ventilation
respectively, and wherein said vacuum measured at said distal end
of said catheter is typically in the range of -3 to -25 cmH2O.
16. A method as in claim 2 wherein said ventilation comprises
alternating positive pressure gas delivery and application of
vacuum, wherein the amplitude of said vacuum collapses the bronchii
feeding said area to trap said delivered gas in said area and
wherein said vacuum amplitude is typically in the range of -15 to
-50 cmH2O.
17. A method as in claim 2 wherein said ventilation comprises fluid
flow rates of 0.05 to 10 lpm.
18. A method as in claim 2 wherein said bronchus feeding said
targeted lung area remains patent during said ventilation and is
not occluded with said catheter.
19. A method as in claim 2 wherein said catheter comprises an
occlusion means wherein said occlusion means occludes said bronchus
feeding said targeted lung area during said ventilation and wherein
said occlusion is continuous or intermittent and a desired
intermittence.
20. A method as in claim 2 wherein said ventilation comprises
passive gas exhaust from said area around the outside of said
catheter.
21. A method as in claim 2 wherein said ventilation comprises gas
delivery wherein said gas is a therapeutic gas, such as but not
limited to 100% O2, Helium, HeliOx or Nitric Oxide.
22. A method as in claim 2 wherein said ventilation comprises fluid
delivery wherein said fluid is a therapeutic fluid, such as but not
limited to Perfluorocarbon, surfactant or mucolytic.
23. A method as in claim 2 wherein said ventilation comprises
delivery of therapeutic substances, such as but not limited to
mucolytic agents, surfactants, beta-agonists, anti-inflammatories,
steroids, antibiotics, vitamin derivatives, vasodilators, viral
vector agents, mono-clonal antibodies, chemotherapeutics,
radioactive isotopes or stem cells.
24. A method as in claim 2 wherein said ventilation is performed on
a patient concurrent with positive pressure ventilation from a
mechanical ventilator, wherein the catheter is inserted into said
patient's tracheobronchial tree through an artificial airway, such
as but not limited to a tracheal tube, oropharyngeal tube, a rigid
bronchoscope or a breathing mask.
25. A method as in claim 2 wherein said ventilation is performed on
a naturally breathing patient, wherein said catheter is inserted
into said patient's tracheobronchial tree through a natural channel
or percutaneously through an unnatural channel such as a
cricothyrotomy or tracheotomy.
26. A method as in claim 2 wherein the procedure is performed on
different lung areas simultaneously or sequentially, or on the same
lung area sequentially and wherein said lung areas include a
bronchopulmonary compartment of the lung, such as but not limited
to an entire lung, a lobe, a lobar segment, a lobar subsegment or a
lobar sub-subsegment
27. A method as in claim 2 wherein the procedure is performed
acutely for a period of 1-24 hours, subacutely for a period of 1-14
days, or chronically for more than 14 days.
28. A method as in claim 2 wherein said catheter is guided to the
targeted lung area with a guiding means such as but not limited to
an endoscopic means, a fluoroscopic means, a guidewire or guiding
catheter means, or an obturator means.
29. A method as in claim 2 wherein said ventilation is paused by
removal of said catheter and wherein a guidewire is left in place
to facilitate re-insertion of said catheter, and wherein said
ventilation is resumed by subsequent re-insertion of said
catheter.
30. A method for directly aspirating an area of a lung via a
continuously indwelling catheter placed in the bronchial tree,
wherein said catheter has a distal end and a proximal end, wherein
said distal end is anchored in the bronchus of said lung area, and
wherein said proximal end is connected to an vacuum source external
to the patient, and wherein said catheter can remain in place for
extended periods without vigilance.
31. A method as in claim 31 wherein said aspiration comprises a
positive pressure venturi gas jet at the distal end of said
catheter wherein said jet is directed in the proximal direction
away from targeted said lung area.
32. A method for blocking airflow into a compartment of a lung with
an occlusion means, said occlusion means comprising a continuously
indwelling catheter with an occlusion member at said catheter's
distal end, wherein the proximal end of said catheter remains
external to the patient and wherein said catheter can remain in
place for extended periods without vigilance.
33. A method as in claim 33 wherein said catheter includes a lumen
and wherein a vacuum is delivered to said lung compartment via said
lumen, wherein said vacuum is delivered continuously,
intermittently or variably.
34. An apparatus and kit for the purpose of directly ventilating a
lung area, comprising: a. A catheter with a distal and proximal end
with at least one lumen for fluid flow, comprising: i. at its
distal end an anchoring means to anchor said distal end of said
catheter in a bronchial lumen for extend periods while the catheter
is unattended by a clinician; ii. comprising at its proximal end a
connection means for connection to a ventilation control source
external to the patient; iii. comprising between said distal and
proximal ends a securing means concentric with the shaft of said
catheter for sealing, tensioning and connecting said catheter shaft
to the entry point of said catheter into the body; b. A ventilation
Gas Control Unit comprising: i. an integral compressed supply of
ventilation gas, or an input connection to an external ventilation
gas supply, and comprising an output connection means for
connection of said catheter's proximal end and comprising a
coupling means to couple said gas with said catheter's fluid lumen,
and comprising pressure or flow measurement and regulation means,
such as but not limited to amplitude regulating valves, on-off
valves, pumps, switches and sensors, to produce and regulate a
desired output of said ventilation gas; ii. an integral vacuum
supply means, or an input connection to an external vacuum supply,
and comprising a connection means for connection of said catheter's
proximal end and comprising a coupling means to couple said vacuum
with said catheter's fluid lumen, and further comprising a pressure
or flow measurement and regulation means such as but not limited to
amplitude regulating valves, on-off valves, pumps, switches and
sensors, to produce and regulate a desired output of said vacuum;
iii. a user interface for selection of the desired output and
ventilation parameters and for displaying selected, measured and
regulated input and output parameters.
35. An apparatus as in claim 34 wherein said catheter anchor is a
non-occlusive member such as but not limited to an inflatable
member or a radially compressible wire structure such as a
thermoplastic or shape memory alloy wire.
36. A catheter as in claim 34 wherein said catheter comprises an
outer sleeve axially slide-able about said catheter shaft and
further wherein said anchor is compressed between said catheter
shaft and sleeve, and wherein axial retraction of said sleeve
releases said anchor to expand.
37. An apparatus as in claim 34 wherein said catheter anchor
comprises a clip member, said clip configured for attachment to a
bronchial bifurcation or septum.
38. An apparatus as in claim 34 wherein said catheter anchor
comprises an occlusive member, such as but not limited to an
inflatable or deflatable member.
39. An apparatus as in claim 34 wherein said catheter distal end
includes an occlusive member to occlude a bronchus and a
non-occlusive anchor to anchor said catheter in a bronchus.
40. An apparatus as claim 34 wherein the said catheter comprises a
lumen in which a guiding member is placed, such as but not limited
to a guidewire, guiding catheter or obturator, and wherein said
guiding member includes said anchor at its distal end wherein said
anchor protrudes from the distal tip of said catheter.
41. An apparatus as in claim 34 wherein the said catheter comprises
at least two lumens, one for gas delivery and one for gas removal
by vacuum.
42. A catheter as in claim 34 wherein said catheter comprises a
connection means, said connection means positioned generally near
the middle of said catheter's length, and wherein said connection
means comprises re-attachable detachment of the proximal section of
said catheter which is external to the body.
43. A catheter as in claim 34 comprising a sealing and tensioning
means concentric to and axially slide-able to said catheter's shaft
such as but not limited to a means to seal and secure said catheter
to a percutaneous access site in the neck or to seal and secure
said catheter shaft to an artificial airway such as a tracheal
tube.
44. A catheter as in claim 34 wherein at least the distal end of
said catheter comprises a plurality of branches wherein said
branches are configured for cannulating multiple bronchi
simultaneously.
45. An apparatus as in claim 34 wherein at least one said catheter
is movably slideable in at least one lumen in a tracheal tube.
46. A catheter as in claim 34 comprising a length of 25 to 300 cm,
an other diameter of 1 to 5 mm, a ventilation gas delivery lumen
effective diameter of 0.1 to 3 mm, optionally a vacuum gas removal
lumen effective diameter of 0.5 to 3.0 mm, optionally a guiding
member lumen effective diameter of 0.3 to 1.0 mm, an anchoring or
occlusion member free state diameter of 4 to 25 mm.
47. A catheter as in claim 34 comprising an extruded thermoplastic
or thermoset tubular material construction, optionally a filament
structure within the wall of said tubular construction, said
material comprising a durometer of 30-70 Shore A, said material
optionally comprising a therapeutic compound such as but not
limited to an antibiotic, antimicrobial or antifungal coating, and
comprising a radiopaque constituent or optionally radiopaque
markings.
48. A catheter as in claim 34 comprising at least one section
comprising a means for length shortening or lengthening, such as
but not limited to circumferential ridges, said section absorbing
tension and compression imparted by external forces.
49. A catheter as in claim 34 comprising a port near said distal
end said port directed proximally away from targeted lung area, and
wherein said port communicates with a lumen in said catheter
wherein said lumen is connected to a pressure source, and further
wherein said Gas Control Unit delivers a pressurized gas to said
lumen thus entraining gas in said targeted area to be exhausted
proximally with said delivered gas.
50. A Gas Control Unit as in claim 34 integral to and or re-movably
attachable to a mechanical ventilator.
51. A Gas Control Unit as in claim 34 comprising features for
portability and wear-ability by the user, such as but not limited
to an internal battery, an internal pressurized gas source, an
internal vacuum source, and a belt clip, fanny pack or shoulder
strap.
52. A Gas Control Unit as in claim 34 comprising a replaceable or
refillable ventilation gas cartridge.
53. A Gas Control Unit as in claim 34 comprising or a pressure
measuring means or a gas concentration measuring means, such as but
not limited to the CO.sub.2 concentration of gas removed from the
treated area, to determine the completeness of native gas
displacement from the treated area, or to determine and adjust the
ventilation parameters as appropriate to optimize the therapy.
54. A apparatus as in claim 34 further comprising a kit, the kit
comprising a ventilation catheter with sleeve connector, an access
incision plug, a guiding catheter, a Gas Control Unit, a quantity
of ventilation gas, a portable case, a spare battery and battery
charger, cleaning supplies, a hygienic seal for sealing distal
section of catheter when proximal section is removed, and an
instruction sheet.
55. A system for site-specific ventilation of an area of a lung of
a patient, comprising: an indwelling catheter adapted to be
disposed in a bronchus of a poorly ventilated lung area to provide
direct ventilation to that area, the indwelling catheter including
at least one lumen, a distal end and a proximal end, an anchor
disposed on the distal end of the catheter, the anchor being
adapted to dilate a bronchus to secure the indwelling catheter in
position for an extended time, a gas control unit coupled to the
catheter to control flow through the lumen of the catheter, a gas
delivery system coupled to the catheter and the gas control unit,
the gas delivery system being adapted to provide ventilation gas
through the lumen of the catheter to the area of the lung, a gas
removal vacuum system coupled to the catheter and the gas control
unit, the gas removal system being adapted to suction CO.sub.2 rich
stagnant gas from the area of the lung through the lumen of the
catheter, wherein the gas control unit is adapted to control the
gas removal and delivery systems to deliver and suction gas through
the catheter to and from the area of the lung without total lung
mechanical ventilation and without collapsing the area of the
lung.
56. The system of claim 55, further comprising: a patient
respiration sensor coupled to the gas control unit to synchronize
the gas delivery system and the gas removal system to a patient's
spontaneous inspiratory phase and expiratory phase.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This application is a Continuation of U.S. patent
application Ser. No. 10/870,849, filed Jun. 17, 2004, which claims
priority to Provisional Patent Application No. 60/479,213, filed
Jun. 18, 2003, both of which are incorporated herein in their
entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable
DESCRIPTION OF ATTACHED APPENDIX
[0003] Not Applicable
GOVERNMENT INVENTION OR CONTRACT WITH GOVERNMENT
[0004] None
ENTITY
[0005] Small Entity Concern
PRIOR ART
[0006] U.S. Pat. Nos.: 4,825,859; 4,838,255; 4,850,350; 4,967,743;
5,000,175; 5,134,996; 5,186,167; 5,193,533; 5,255,675; 5,460,613;
5,513,628; 5,598,840; 5,791,337; 5,904,648; 6,227,200; 6,520,183;
6,575,944; 6,575,944; U.S. Published Patent Applications:
20010035185; 20020179090.
OTHER RELATED PUBLICATIONS
[0007] Fink J. B.; Helium-oxygen: An Old Therapy Creates New
Interest. (J Resp Care Pract April 1999; 71-76) [0008] Christopher
K L et al.; Transtracheal oxygen for refractory hypoxemia. (JAMA
1986; 256: 494-7) [0009] Gaebek J. B. et al; Efficacy of Selective
Intrabronchial Air Insufflation in Acute Lobar Collapse. (Am J of
Sur 1992; 164:501-505) [0010] AARC Clinical Practice Guideline:
Oxygen Therapy in the Home or Extended Care Facility (Respir Care
1992; 37:918-922) [0011] Maclntyre, Neil; Long-term Oxygen Therapy:
Conference Summary (Respir Care 2000; 45(2):237-245) VHA/DOD
Clinical Practice Guideline for the Management of Chronic
Obstructive Pulmonary Disease (VHA 1999 August 116) [0012] Blanch,
L; Clinical Studies of Tracheal Gas Insufflation (Respir Care 2001;
46(2):158-166)
BACKGROUND OF THE INVENTION
[0013] The present invention relates to the field of respiratory
therapy and specifically to the field of lung ventilation to treat
a variety of pulmonary diseases.
[0014] Lung diseases are the number one category of diseases and a
leading cause of death worldwide. Some lung diseases, such as
Chronic Obstructive Pulmonary Disease (COPD), Acute Respiratory
Distress Syndrome (ARDS), Severe Acute Respiratory Syndrome (SARS)
and cystic fibrosis (CF) usually require some form of ventilation
assistance or delivery of therapeutic agents in order to clinically
improve the patient.
[0015] COPD in particular effects tens of millions of people and is
one of the top five leading causes of death. COPD is a spectrum of
problems, including bronchitis and emphysema, and involves airway
obstruction, lung elasticity loss and trapping of stagnant
CO.sub.2-rich air in the lung. Emphysema, the worst form of COPD,
occurs when there is a breakdown in the elasticity in the lung
changing clusters of individual alveoli into large air pockets,
thereby significantly reducing the surface area for gas transfer.
In some cases air leaks out of the compromised walls of the minute
airways to the periphery of the lung causing the membranous lining
to separate and forming large air vesicles called bullae. Also due
to elasticity loss, small conducting airways leading to the alveoli
become flaccid and have a tendency to collapse during exhalation,
trapping large volumes of air in the now enlarged air pockets, thus
reducing bulk air flow exchange and causing CO.sub.2 retention in
the trapped air. Mechanically, because of the large amount of
trapped air at the end of exhalation, known as elevated residual
volume, the intercostal and diaphragmatic inspiratory muscles are
forced into a pre-loaded condition, reducing their leverage at the
onset of an inspiratory effort thus increasing work-of-breathing
and dyspnea. Also, areas with more advanced emphysema and more
trapped air tend to comprise the majority of the chest cavity
volume and tend to fill preferentially during inspiration due to
their low elasticity, thus causing the healthier portions to be
disproportionately compressed rather than inflating normally during
inspiration and receiving their share of inspired air. In emphysema
therefore more effort is expended to inspire less air and the air
that is inspired contributes less to gas exchange.
[0016] ARDS is a respiratory insufficiency caused by a variety of
underlying problems such as lung injury, infection, edema, or
atelectasis. SARS is a sudden respiratory insufficiency and appears
to be caused by a viral infection. CF is a genetic condition in
which airways secrete copious amounts of mucus and are
inflamed.
[0017] Conventionally prescribed therapies for COPD and ARDS and
sometimes SARS and CF include pharmacological agents
(beta-agonists, aerosolized bronchodilators, anti-inflammatories
and mucolytics), supplemental long term oxygen therapy (LTOT)
delivered nasally or via tracheotomy, BiLevel Continuous Positive
Airway Pressure (BiPAP), which lowers work of inspiration by
providing a steady stream of pressure, Tracheal Oxygen Gas
Insufflation (TGI), described by Christopher, JAMA 1986; 256:
494-7, which reduces CO.sub.2 content in the upper airways thus
allowing higher O.sub.2 concentrations to reach the distal airways,
respiratory muscle rehabilitation, pulmonary hygiene, such as
lavage and percussion therapy, lung volume reduction surgery (LVRS)
and lung transplantation (LX). These therapies all have certain
disadvantages and limitations with regard to effectiveness,
targeting accuracy, risk or availability. Usually, after
progressive decline in lung function despite attempts at therapy,
patients become physically incapacitated or sometimes require more
invasive mechanical ventilation to survive in which case weaning
from ventilator dependency is often times difficult. Conventional
invasive ventilation modes include Continuous Mechanical
Ventilation (CMV), Synchronized Intermittent Mechanical Ventilation
(SIMV), Positive End Expiratory Pressure (PEEP) therapy, and high
frequency jet ventilation (HFJV).
[0018] Some newer ventilatory methods have been studied in the
attempt to improve treatment of COPD and ARDS. One such method
described by Fink, J Resp Care Pract April 1999; 71 is ventilation
of a lung with gases of low molecular weights and low viscosity,
such as helium-oxygen mixtures or nitric oxide, in order to
decrease gas flow resistance and lower surface tension in distal
airways and alveolar surfaces, thus increasing oxygen transfer
across the alveolar surface into the blood. Another new method
includes liquid perfluorocarbon ventilation which can displace
mucus in distal airways while still conducting oxygen thus
improving gas flow. Another method never successfully
commercialized is Negative End Expiratory Pressure (NEEP), which
helps remove CO2-rich gas during the exhalation cycle. These
invasive methods typically ventilate COPD and ARDS patients more
effectively then conventional invasive ventilation modes and may
improve weaning, but they are significantly limited in efficacy
because they can not easily be provided as chronic treatments and
are not target specific. Rather they are inherently designed to
treat the whole lung from the upper airway and hence do not address
the significant problem of hyperinflation and areas of trapped
stagnant gas, nor the problem of maldistribution of inspiratory gas
volume.
[0019] Some additional devices and techniques have been invented
with the aim of improving efficacy. U.S. Pat. No. 6,575,944
describes a catheter that is used for medication delivery through
an endotracheal tube. That invention is good for pharmacological
therapy on a mechanically ventilated patient, however the invention
does not address the significant ventilation needs of the diseased
lungs such as trapped gas and hyperinflated lungs.
[0020] U.S. Pat. No. 6,520,183 describes a catheter used to block
on lung and delivery anesthesia to the other lung. That invention
and other like it can only be used for one lung ventilation, almost
always for surgery. That invention can be used in the unintended
use of shunting ventilation to one lung, if the other lung is too
diseased, however this usage would have significant limitations in
that lobar or segmental sections of lung could not be individually
blocked; hence this therapy would not be selective at all.
[0021] U.S. Pat. Nos. 6,227,200; 5,791,337; 5,598,840; 5,513,628;
5,460,613; 5,134,996; and 4,850,350 all describe catheters used for
intermittently accessing and suctioning the trachea and main stem
bronchi during through a tracheal tube during mechanical
ventilation. That invention does not address the severe ventilation
problems of the diseased lung, such as trapped air, hyperinflation,
and poor airflow and perfusion distribution.
[0022] U.S. Pat. No. 5,904,648 describes a catheter for blocking
airflow to one lung in order to ventilate and deliver anesthesia to
the other side while the blocked side is being operated on. Again,
that invention does not address improving ventilation and gas
exchange.
[0023] U.S. Pat. Nos. 5,255,675 and 5,186,167 describe a catheter
placed in the trachea through which the trachea is insufflated with
oxygen. In clinical practice that invention and others like it have
been proven to reduce the amount of CO2 in the lung and thus
improve ventilation, however because the therapy described in this
invention can inherently only be applied to the upper airways, it
does nothing to improve the significant hyperinflation, air
trapping and airflow and perfusion maldistribution of diseased
lungs, and thus the therapy is severely limited. Indeed this
therapy has not been well received clinically because the amount of
benefit does not justify the added attention required.
[0024] U.S. Pat. No. 5,193,533 describes an invention similar to
U.S. Pat. No. 5,255,675 in which high frequency ventilation is
administered to the trachea to improve oxygenation. That invention
has been proven clinically useful during short term medical
procedures because the lung can be effectively mechanically
ventilated at lower pressures but it is not useful as a subacute or
chronic therapy as it does not reduce the air trapping,
hyperinflation, or airflow and blood perfusion maldistribution.
[0025] U.S. Pat. Nos. 4,967,743; 4,838,255 and 4,825,859 describe a
catheter for suctioning and lavaging the airways. That invention is
limited to managing the airway integrity and pulmonary hygiene and
is not suited for directly improving the underlying causes of air
trapping, hyperventilation, and air flow maldistribution in the
lung.
[0026] U.S Patent Application 20020179090 describes an aspiration
catheter for removing phlegm from a lung. This invention is only
useful in airway management and is not suited for directly
improving the underlying causes of air trapping, hyperventilation,
and air flow maldistribution in the lung.
[0027] U.S Patent Application 20010035185 describes a
nasal-pharyngeal catheter for delivering breathing gases to the
pharynx to supplement regular ventilation or breathing. That
invention is incrementally more effective than LTOT in that the
gases are delivered more effectively but unfortunately the
technique can not directly improve the underlying causes of air
trapping, hyperventilation, and air flow maldistribution in the
lung
[0028] It must be emphasized that an effective ventilation
treatment should ideally target specific areas of the lung that are
most diseased yet all the methods described in the prior art employ
ventilation on the entire lung as a whole, rather than on targeted
lung areas that are more diseased. Therefore, all known ventilation
modes allow trapped CO2 to persist in the worst effected areas of
the lung and allow these areas to remain hyperinflated with the
CO2-rich air, thus taking up valuable space in the chest cavity and
compressing other potentially contributory lung areas. Other
inventions or conventional therapies are either to traumatic, too
transient, not site-specific, too experimental or not effective.
The present invention disclosed herein addresses these shortcomings
as will become apparent in the later descriptions.
BRIEF SUMMARY OF THE INVENTION
[0029] The present invention disclosed herein takes into
consideration the problems and challenges not solved by the
aforementioned prior art methods. In summary, this invention
accomplishes (1) effective and direct cannulation of the lung area
requiring treatment for a targeted site-specific treatment, (2)
provides the option of sub-chronic or chronic treatment without the
vigilance of a clinician, either in the hospital setting or in the
home-care setting, and can be titrated accordingly, (3) is
atraumatic, (4) improves hyperinflation and stagnant gas trapping
in the distal spaces, (5) improves the maldistribution of airflow
and blood perfusion, and (5) is cost effective.
[0030] The present invention provides a method for directly
ventilating an area in a lung to improve the gas exchange in that
area, typically for the treatment of COPD, although other
respiratory diseases, such as ARDS, SARS, CF and TB may also
benefit from this approach. The method, Trans-Tracheobronchial
Segmental Ventilation (TTSV), is performed by (a) catheterizing the
lung area with an indwelling catheter that can be left in place for
extended periods without the vigilance of a clinician, and (b)
ventilating the lung area via the catheter by delivering a
ventilation gas and/or therapeutic substance such as a gas, liquid,
solid or plasma, during an insufflation phase and removing waste
and mixed gases from the area during an exhaust phase. The
scientific principles employed to accomplish TTSV are fluid
dynamics, the physical laws of mass transfer, i.e., gas and tissue
diffusivity, gas concentration gradients and pressure gradients, as
well as the physical laws of collapsible tubes and hemoglobin
biochemistry laws.
[0031] In a preferred embodiment of the present invention the
feeding bronchus of the targeted lung area is catheterized with an
indwelling catheter anchored in the bronchus such that it can
remain in place for extended periods without being attended by a
person. The catheter enters the bronchial tree from the upper
airway, either through an artificial airway such as a tracheal tube
or through a natural airway such as the nasal passage or through a
percutaneous incision such as a cricothyrotomy and is advanced to
the targeted LUNG AREA through the bronchial tree with endoscopic
or fluoroscopic guidance, where the tip is anchored in the airway.
For ventilation and hygiene considerations, the catheter entry
point into the body typically includes a self-sealing and
tensioning connector that controls fluid from escaping from around
the catheter shaft, but which permits the catheter to slide axially
to compensate for patient movement or for elective catheter
repositioning. The tensioning connector also serves to prevent
inadvertent dislodging of the catheter's distal end anchor from the
bronchus. In accordance with this embodiment the catheter includes
at least one lumen through which the ventilation or therapeutic gas
is delivered or insufflated directly into the targeted lung area
and through which CO2-rich mixed gas is removed or exhausted from
the targeted area. Gas removal from the area is typically enhanced
by applying vacuum, as opposed to passive exhaust, however a low
vacuum level is applied to avoid the collapse of airways and
trapping gas behind the then collapsed airways. Optionally the
segmental ventilation gas delivery/removal cycle is synchronized
with the breathing pattern of the complete lung either during
natural breathing or during mechanical ventilation but can also be
asynchronous. The primary segmental ventilation parameters, flow,
pressure and frequency, are regulated so as to create the desired
volume delivery to the targeted area, or alternatively the desired
pressure delivery to and in the targeted area, or still
alternatively the desired gas composition in the targeted area or
perfusion network thereof. The segmental ventilation parameters are
measured to facilitate such regulation and to maintain safe
conditions such as to prevent barotrauma.
[0032] Still in accordance with the preferred embodiment of the
present invention, the fluid delivered to the targeted area may
include standard breathing gases such as filtered air-oxygen
mixtures, or may include therapeutic gases, such as helium,
helium-oxygen mixtures, nitric oxide, other low molecular weight
gases and gases enriched with particalized medicants, or may
include liquids such as perfluorocarbons. Hereafter, the various
fluids potentially used in TTSV will be referred to as simply
`ventilation gas`.
[0033] Still in accordance with the preferred embodiment of the
present invention, the proximal end of the catheter is kept
external to the patient and is connected to a segmental ventilation
gas control unit. The gas control unit comprises a supply of
ventilation gas, or alternately an input connection means to a
supply thereof, and comprises the requisite valves, pumps,
regulators, conduits, sensors and control electronics to control
the desired pressure and/or flow delivery of the gas and to control
the desired pressure in the lung area. The gas control unit may
comprise a replaceable or refillable modular cartridge of
compressed or concentrated ventilation gas and/or may comprise a
pump system that receives ventilation gas from a reservoir and
ejects the ventilation gas into the catheter at the desired
parameters. The gas control unit further comprises fail-safe
over-pressure relief mechanisms to protect against inadvertent lung
barotrauma. The gas control unit also typically comprises a
negative pressure generating source and control system also
connectable to a lumen in the catheter for the previously described
gas removal phase, i.e., exhaust phase, of the gas control unit
ventilation cycle. The gas control unit may be configured to be
remove-ably or permanently attached internally or externally to a
standard lung ventilator, in the case of performing gas control
unit on a mechanically ventilated patient, or may be an independent
unit optionally to be worn by an ambulatory patient, in the case of
performing TTSV on for example a home-based naturally breathing
patient. It is appreciated that the gas control unit will have the
requisite control and monitoring interface to allow the user to
control and monitor the relevant parameters of the TTSV, as well as
the requisite power source, enclosure, electronics, etc.
[0034] In an optional embodiment of the present invention, an
average pressure is created in the targeted lung area which is
slightly elevated compared to the average pressure in the remainder
of the lung. This is achieved by measuring and regulating the lung
area and TTSV parameters accordingly. The purpose of the elevated
pressure is four fold: (1) it will facilitate a dilatation of the
distal airways to facilitate communication of the ventilation gas
with the otherwise poorly communicating lung lobules and alveoli;
(2) it will facilitate CO2 displacement out of the elevated
pressure area into areas of lower pressure due to simple flow and
pressure gradient laws; (3) it will facilitate displacement of
CO2-rich gas out of very distal areas through collateral channels
at the alveolar and lobular level into neighboring lung areas; (4)
it will increase the rate of ventilation gas diffusion across the
alveolar surface into the blood due to higher gas partial
pressures, obeying diffusivity laws and hemoglobin biochemistry
laws. Conversely, the average pressure created in the targeted area
can also be regulated to produce a slightly lower average pressure
than the remainder of the lung, in order to facilitate volume
reduction of the targeted hyperinflated area.
[0035] TTSV can be performed by delivering ventilation gas to the
targeted area but without applying an active exhaust phase as
opposed to the previously described active exhaust phase. Or,
alternatively, active insufflation and expiratory phases can
simultaneously co-exist, rather than alternating between phases.
Still alternately gas delivery and active gas exhaust can be
continuous or semi-continuous rather than alternating with discrete
phases of off and on. In any case, insufflation gas pressure and
flow can be delivered continuously, variably, intermittently at low
frequency, <20 cycles/min., intermittently at medium frequency,
20-50 cycles/min., intermittently at high frequency, >50
cycles/min., or synchronized with the patient's breathing cycle in
order optimize the airflow fluid dynamics of TTSV. In the case of
non-active expiration, the CO2-rich gas is simply displaced by the
insufflation gas and exits the targeted lung area passively due to
concentration and pressure gradients. It can be appreciated that
the possible combinations of pressure amplitudes and frequency
profiles of both delivered and exhausted gases are extensive, but
all must comply with the following fundamental and critical
principle that is unique to the present invention: The regulated
parameters must produce a decrease in stagnant gas in the treated
area, produce an increase in beneficial gas in the treated area,
avoid excessive or unsafe pressure and volume increases in the
treated area, and ideally reduce the volume in the treated area to
redistribute inspired air to other healthier lung areas.
[0036] In a second general embodiment of the present invention,
regulation of the pressure in the ventilated segment is further
facilitated by occluding the annular space between the catheter and
the feeding bronchus of the ventilated segment. This embodiment
further facilitates control of the pressure and gas concentration
in the targeted lung area particularly in gravitationally
challenging situations, for example when a non-gaseous substance is
used in the ventilation fluid, or when a low molecular weight gas
is used.
[0037] In a third general embodiment of the present invention, TTSV
of targeted lung area is performed using gas removal only, rather
than both gas delivery and gas removal. In this embodiment can be
accomplished by applying, via the catheter, a vacuum to the area,
or can be accomplished by creating a venturi effect by establishing
a high velocity gas jet of positive pressure in the proximal
direction to entrain gas out of the targeted lung area. The vacuum
created by these later embodiments is typically very low level to
avoid bronchial collapse, which may be determined by measuring gas
flow and adjusting the vacuum level accordingly. Again, this form
may be continuous, intermittent or variable and can be synchronized
with the breathing cycle. It is understood that either form of gas
evacuation will include the appropriate modifications to the gas
control unit previously described.
[0038] In forth general embodiment of the present invention, a
ventilation gas is delivered via the catheter into the targeted
area for a desired period after which a vacuum is applied via the
catheter to the bronchii feeding the targeted area also for a
desired period. The vacuum amplitude is selected to collapse the
bronchii thus trapping the ventilation gas in the area. Mixed gases
are forced out during the ventilation gas delivery phase and also a
portion of mixed gases are sucked out of the conducting airways
immediately before their collapse at the beginning of the vacuum
phase. The sequence is repeated successively until a predominant
concentration of ventilation gas and minority of native gas
occupies the area.
[0039] In a fifth general embodiment of the present invention, in
order to improve ventilation in the lung as a whole, a segment
which is not contributing much to gas exchange is blocked with an
occlusive catheter to shunt inspired gas to other areas of the lung
that are less diseased. Known as Trans-Tracheobronchial Segmental
Shunting (TTSS), this embodiment can be useful considering that the
more diseased less elastic areas preferentially fill with inspired
air which does not reach the alveoli because of the large amount of
stagnant trapped gas. TTSS can be performed continuously,
semi-continuously, dynamically, or intermittently, or synchronized
with the patients breathing cycle. TTSS can also be performed
concurrently with some level of active gas removal using vacuum,
and therapeutic gas or agent delivery into the blocked targeted
area through the TTSS catheter. TTSS can also be performed with
intermittent removal of the shunt but without removal of the
catheter.
[0040] It should be noted that in some applications and embodiments
of this invention, the TTSV or TTSS procedure is performed as a
temporary palliative procedure with dramatic clinical benefit
during the actual therapy but with a dissipating benefit after the
therapy is discontinued. In other applications and embodiments,
TTSV or TTSS is performed during mechanical ventilation to more
effectively ventilate a patient, for example acutely to wean a
patient from ventilatory support, or subchronically or chronically
to improve ventilation in ventilatory-dependent patients. Still in
other cases, TTSV or TTSS is performed on a naturally breathing
patient as a chronic therapy either continuously or intermittently
in order to provide clinical benefit lasting periods of weeks or
even years. In this later embodiment, the catheter may be removed
after a treatment while leaving a hygienic seal at the percutaneous
access point, and a new catheter later inserted for a subsequent
treatment. A guidewire might be left in place to ease subsequent
re-catheterization. It should also be noted that the TTSV or TTSS
procedure may be performed simultaneously on different lung areas
or sequentially on the same or different lung areas. It should also
be noted that TTSV or TTSS can be extremely useful for gradually
reducing bulla in bullous emphysema, particularly if a stream of
low molecular weight gas such as HeliOx is insufflated into the
targeted lung area and mixed gases are removed with aspiration.
Finally it should be noted that the TTSV or TTSS procedure can be
performed on a relatively few large sections of lung, for example a
lobe or a few lobar segments on patients with heterogeneous or
bullous emphysema, or can be performed on many relatively small
sections of lung, for example twelve sub-subsegments on patients
with diffuse homogeneous emphysema. The procedure and treatment can
even be performed on an entire lung by catheterizing a left or
right mainstem bronchus, or both lungs by catheterizing the
trachea.
[0041] As previously noted no methods exist in the prior art
wherein a poorly functioning lung area with trapped CO2-rich gas is
more effectively ventilated by directly delivering ventilation
gases to that area and/or removal of CO2-rich gas from that area,
or of bronchial shunting of inspired air from a local lung area to
other lung regions.
[0042] It should be noted that while preferred and optional
embodiments of the present invention are described, there are other
useful embodiments not specifically stated but are implied as part
of the present invention which combine various features of the
described embodiment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0043] FIG. 1 describes the anatomy of a lung and placement of the
TTSV catheter.
[0044] FIG. 2 describes conventional ventilation therapies for
treating compromised lungs.
[0045] FIG. 3 depicts TTSV therapy on a naturally breathing
patient.
[0046] FIG. 4 depicts TTSV therapy during mechanically
ventilation.
[0047] FIG. 5 describes the effect of TTSV therapy on a naturally
breathing patient.
[0048] FIG. 6 describes the effect of TTSS therapy on a
mechanically ventilated patient.
[0049] FIG. 7 describes optional TTSV treatment parameters.
[0050] FIG. 8 describes a typical TTSV catheter.
[0051] FIG. 9 describes typical TTSS catheters.
[0052] FIG. 10 describes optional TTSV and TTSS catheter
configurations.
[0053] FIG. 11 describes an over-guidewire and exchange catheter
configuration.
[0054] FIG. 12 describes means to allow the TTSV catheter to remain
in place without irritating the bronchial walls.
[0055] FIG. 13 describes the TTSV Gas Control Unit.
[0056] FIG. 14 describes a TTSV Kit.
DETAILED DESCRIPTION OF THE INVENTION
[0057] Referring to FIG. 1 the lung anatomy is described including
the left 30 and right 31 lung, trachea 32, the left main stem
bronchus 33, the five lung lobes 36, 37, 38, 39, 40, a lateral
fissure 41 separating the left upper and lower lobe, and the
diaphragm 42 which is displaced downward indicative of a
hyperinflated emphysematous lung. FIG. 1a shows a cut away view of
the left upper lobe bronchus 43, the apical segmental bronchus 44
of the left upper lobe, the parietal pleura 45, the visceral pleura
46 and the pleural cavity 47. Large bulla 48 are membranous air
vesicles created on the surface of the lung between the visceral
pleura 46 and lung parenchyma 51 due to leakage of air out of the
damaged distal airways and through the lung parenchyma. The air in
the bullae is highly stagnant and does not easily communicate with
the conducting airways making it very difficult to collapse bullae.
Pleural adhesions 49 are fibrous tissue between the visceral pleura
46 and the parietal pleura 45 which arise from trauma or tissue
fragility. These adhesions render it difficult to acutely deflate
an emphysematous hyperinflated lung compartment without causing
tissue injury such as tearing, hemorrhage or pneumothorax. FIG. 1b
shows an exploded view of the upper lobe apical segment 52 and the
anterior segment 54. FIG. 1d describes a non-emphysematous lung
lobule which includes the functional units of gas exchange, the
alveoli 55, and CO2-rich exhaled gas 58 easily exiting the
respiratory bronchiole 56, Also shown are intersegmental collateral
channels 57, typically 40-200 um in diameter, which communicate
between bronchopulmonary segments making it difficult for a lung
compartment to collapse or remain collapsed because of re-supply of
air from neighboring compartments through these collateral
channels. Detail C in FIG. 1c describes an emphysematous lung
lobule in which the alveolar walls are destroyed from elastin
breakdown resulting in large air sacks 59. The emphysematous lobule
traps air becoming further hyperinflated because the respiratory
bronchiole leading to the engorged lobule collapses 60 during
exhalation, thus allowing air in but limiting air flow out 61.
[0058] FIG. 1 also shows the TTSV catheter 170 anchored in the
apical segment bronchus 44. In FIG. 1b, the TTSV ventilation gas 71
is shown being delivered by the TTSV catheter 170. The native gas
72 in the targeted apical segment is forced out of the apical
segment 52 proximally alongside the catheter 170 and also across
intersegmental collateral channels into the neighboring anterior
segment 54 then proximally up the airways. The native gas may also
be sucked proximally up the catheter. The TTSV parameters are
regulated to produce the desired pressure, volumes and gas
concentrations.
[0059] In FIG. 2 conventional therapies are shown which enhance gas
exchange of a compromised lung. FIG. 2a shows mechanical
ventilation in conjunction with Transtracheal Gas Insuflation (TGI)
using an EndoTracheal Tube 80. Positive pressure is delivered to
the lung via a mechanical ventilator and EndoTracheal Tube and the
trachea 32 is insufflated with oxygen 81 via a dedicated lumen 84
in the EndoTracheal Tube to flush out retained CO2 in the trachea.
This therapy does not address the stagnant gas in the hyperinflated
lung areas that compromise ventilation. FIG. 2b shows long term
oxygen therapy (LTOT) where oxygen 81 is delivered via nasal
cannula 82. Again, while increasing O2 levels in the lung's upper
airways, this therapy does not address the stagnant gas in the
hyperinflated lung areas that compromise ventilation. FIG. 2c shows
transtracheal oxygen therapy (TTOT) wherein oxygen 81 is delivered
directly into the trachea 32 via a tracheotomy 83. While slightly
more effective than LTOT, TTOT still has the same inherent
shortcomings noted.
[0060] FIG. 3 describes a general layout of the invention disclosed
herein, wherein TTSV or TTSS is performed on an ambulatory
spontaneously breathing patient, showing percutaneous access into
the trachea 32, catheterization of the targeted lung area 100,
distal end anchoring 101, entry of the catheter 170 either nasally
102 or through a percutaneous incision 103, connection of the
proximal end of the catheter to the wearable portable Gas Control
Unit 104, in the case of TTSV therapy. Referring to FIG. 3b a
cross-sectional view is shown of entry of the catheter into the
patient showing a percutaneous connector 105 with a through-port
and hygienic seal 106 and a securing means 107 fastening the seal
to the neck of the patient. The hygienic seal 106 also prevents
inadvertent unwanted axial movement of the catheter but allows
desired axial sliding of the catheter in response to anticipated
patient movement. The seal can be left in place to temporarily seal
the incision with a self-sealing membrane or by attaching a plug
108 if the catheter is removed for extended periods.
[0061] FIG. 4 describes a general layout of the invention, wherein
TTSV or TTSS is performed on a ventilatory dependent patient,
showing entry of the catheter 170 through an endotracheal tube 120
which is in the trachea 32 of the patient, catheterization of the
targeted lung area 121, connection of the proximal end of the
catheter 122 to the ventilation Gas Control Unit 123, in the case
of TTSV, as well as the ventilator 124 and breathing circuit It can
be seen that the catheter distal end is anchored 126 in the
targeted bronchus and the catheter shaft at the patient entry point
near the elbow connector 127 is tensioned 128 to prevent
inadvertent unwanted movement with a tensioning and/or sealing
means.
[0062] FIG. 5 graphically describes the effect of TTSV therapy
performed on a naturally breathing patient. At baseline conditions
the targeted lung area has an elevated gas volume 200 and the total
lung has a tidal volume 201 with elevated residual volume 202. Due
to gas trapping the targeted area has a predominant concentration
of CO2-rich 203 stagnant gas with very little fresh CO2 coming from
the blood stream, low blood perfusion due to shunting of blood to
other lung areas, known as the Euhler reflex, and low O2 uptake
204. Work of breathing pressure-volume curves 212 of a breath
indicate gas trapping and labored inspiration and exhalation.
Breath air flow indicates a protracted exhalation 213 due to the
poor lung elastic recoil. The lung itself has hyperinflated upper
lobes 214 and diaphragm displaced downward 215. TTSV is commenced
205 by site-specific ventilation 206 of the targeted area,
typically using 100% Oxygen or HeliOx or some other therapeutic gas
delivered through the indwelling TTSV catheter. After therapeutic
equilibrium, the targeted area gas volume is decreased 207, the
native stagnant gas concentration in the targeted area is reduced
dramatically 208 and is replaced by a high concentration of
therapeutic gas 209 and fresh CO2 from the blood stream 210.
Further, total lung residual volume decreases towards normal 211,
O2 transfer increases 209 towards the normal value of 250 ml/min,
work of breathing is less labored 216 and exhalation flow rate
returns quickly to zero 217 due to improved recoil. The lung itself
is less hyperinflated 218 and the diaphragm position returns toward
normal 219. Depending on the parameters selected and other clinical
factors, the therapeutic conditions can reach equilibrium in 30
minutes to 72 hours
[0063] FIG. 6 graphically describes the effect of TTSS therapy
performed on a mechanically ventilated patient. At baseline
conditions the tidal volume in the lung 250 shows an elevated
residual volume 251 and the volume in the lower lobes is abnormally
low 252. Work of breathing shows poor or high lung compliance 259
in ml/cmH2O, and the overall gas exchange is comprised 253. The
lung itself is hyperinflated, especially the upper lobes 260 and
the diaphragm is displaced downward 261. After commencement of TTSS
therapy the conditions begin to change due to the blocking of the
targeted area by the blocking catheter, and optionally enhanced by
applying a slight vacuum to the blocked area via the catheter. Due
to absorption of the gas in the blocked area, or dissipation of the
gas out of collateral channels, or by slight vacuum applied via the
catheter, the volume in the targeted area decreases as does the
overall lung volume 254 and lung residual volume 255. Some inspired
gas volume is now diverted to the lower lobes 256, the lung
compliance now decreases to a more healthy or elastic level 257 as
shown by the pressure-volume curve of a breath, gas transfer
returns to a more normal level 258, and the lung itself is less
hyperinflated 262 and the diaphragm returns to a more normal
position 263. Equilibrium can be reached between 30 minutes and 72
hours, depending on the targeted area blocked and other clinical
conditions.
[0064] FIG. 7 graphically describes optional TTSV ventilation
parameters with the abscissa and vertical coordinates corresponding
to time and TTSV catheter pressure. FIG. 7a shows intermittent gas
delivery with on 300 and off 301 times. FIG. 7b shows intermittent
gas removal 302 by suctioning. FIG. 7c shows alternating gas
delivery 303 and gas suctioning 304. FIG. 7d shows alternating gas
delivery and suctioning synchronized with the breath cycle so that
TTSV gas delivery 305 occurs during the inspiratory phase 306 and
TTSV gas removal 307 occurs during the expiratory phase 308. FIG.
7e shows TTSV gas removal 309 synchronized with inspiration 306 and
TTSV gas delivery 310 synchronized with exhalation 308. FIG. 7f
shows changing levels and periods of TTSV gas delivery 311 and gas
suctioning 312 wherein the levels are changing in order to maintain
the desired conditions in the targeted area. FIG. 7g shows high
frequency oscillatory gas delivery 313 and gas suctioning 314. FIG.
7h shows constant or static gas delivery 315 concurrent with high
frequency oscillatory gas suctioning 316. FIG. 7i shows high
frequency oscillatory gas delivery 317 concurrent with constant or
static gas suctioning 318. FIG. 7j shows constant gas delivery 319
without any gas suctioning. FIG. 7k shows constant gas delivery 320
concurrent with intermittent gas suctioning 321. FIG. 7l shows
concurrent constant gas delivery 322 and gas suctioning 323. FIG.
7m shows variable gas delivery periods 324 and amplitudes 325 in
order to regulate the desired conditions in the targeted area. FIG.
7n shows constant or static vacuum 326 applied to the targeted lung
area with out any gas delivery. FIG. 7o shows alternating gas
delivery and gas suctioning with a short delivery phase 327 and
extended vacuum phase 328.
[0065] Typical gas delivery and gas suction parameters depend on
the area being treated and the clinical conditions. During
mechanical ventilation, gas delivery can range from 0.1 to 1.5 lmp
and 8 to 40 cmH2O at the lobar segment level and 1.0 to 10.0 lmp
and 10 to 50 cmH2O at the tracheal level. Gas evacuation can range
from 0.1 to 1.5 lmp and -5 to -40 cmH2O at the lobar segment level
and 1.0 to 10.0 lmp and -10 to -50 cmH2O at the tracheal level.
During spontaneous ventilation, flow can range from 0.05 to 1.5 lmp
and 3 to 20 cmH2O at the lobar segment level and 1.0 to 10.0 lmp
and 5 to 30 cmH2O at the tracheal level. Gas evacuation can range
from 0.05 to 1.5 lmp and -3 to -20 cmH2O at the lobar segment level
and 1.0 to 10.0 lmp and -5 to -30 cmH2O at the tracheal level.
Frequencies can range from 1 to 120 cycles per hour if being used
intermittently, and 2 to 120 cycles per minute in oscillatory mode,
and 1 hour to indefinite durations for continuous mode.
[0066] FIG. 8 describes a typical TTSV catheter 170 with a catheter
shaft 180 a distal end 181, a proximal end 182, a proximal end
connector 176 for attachment to the TTSV Gas Control Unit,
connection ports for insufflation flow 175 and suction 176, a
distal end anchoring member 173, a slide-able sleeve 177 for
placement in the percutaneous incision with a self-sealing gasket
179, a connection 178 for detachment of the proximal end of the
catheter, a sleeve 174 for compressing the anchoring member 173, a
mechanism 169 for retracting the sleeve 174, a lumen 168 for the
mechanism 169, a lumen for gas delivery 171 and a lumen for gas
suctioning 172.
[0067] FIG. 9 describes typical TTSS catheter configurations. FIG.
9a shows a dual TTSS catheter device, each catheter comprising a
shaft 150, a balloon 151, for sealing at the distal tip of the
catheter, a connector at the proximal end 152 of the catheter for
optional connection to a suction source, a port 153 for inflation
of the balloon, a through lumen 154 throughout the length of the
catheter for guidewire insertion or for applying suction through
the catheter, a 15 mm swivel elbow connector 155 for attachment to
an endotracheal tube 156 and breathing circuit 157 and a port 158
for insertion of a bronchoscope if needed.
[0068] FIG. 9b shows a dual TTSS catheter integrated into the
construction of an endotracheal tube 160. The TTSS catheters are
slide-able within lumens 161 and 162 in the wall of the
endotracheal tube. The catheters include connectors 163 for
inflation of the occlusion balloons 164.
[0069] FIG. 10 describes alternate TTSV or TTSS catheter systems,
devices and configurations. FIG. 10a shows a catheter with a self
expanding woven wire anchor 400 which expands upon retraction of an
outer sleeve 401 concentric to the catheter shaft 402. The catheter
includes lumens for gas delivery 403 and gas removal 404. FIG. 10b
shows a catheter with an inflatable balloon 405 which serves as an
anchor and a bronchial occluder. The balloon is either electively
inflatable, or is normally inflated and electively deflatable. FIG.
10c describes an inflatable anchor 407 in the shape of radial
spokes 408 and hence anchors the catheter tip but does not occlude
the bronchus. FIG. 10d describes a catheter with both an occlusive
balloon 410 and a non-occlusive anchor 411. FIG. 10e shows a
catheter with an inflatable balloon anchor 414 and in which the
catheter includes a large port 415 communicating with a lumen 416
such that the anchor does not occlude the bronchus. Gas is free to
flow between the treated area 417 and the proximal areas 418 to
avoid the clinical problems of complete bronchial obstruction. FIG.
10f describes a catheter anchor comprised of wire loops 420. FIG.
10g describes a catheter with multiple small lumens 422 for gas
delivery and a large lumen for gas suctioning 423. FIG. 10h shows a
dual lumen catheter comprised of two concentric tubes 425 and 426
forming an inner lumen 427 and annular lumen 428, wherein the inner
tube or lumen is recessed from the catheter tip. Suctioning is
conducted through the annular lumen and gas delivery through the
inner lumen such that the gas delivery can prevent clogging of the
suctioning path by flushing out any debris 429. FIG. 10i describes
a tri-lumen catheter with a lumen 432 for passage of a guidewire
433 wherein the guidewire may comprise a compressible anchoring
feature 434 that can be retracted into the catheter lumen. FIG. 10j
shows a dual lumen catheter in which the tip has been shaped to
bend one lumen 440 180.degree. such that the end of the lumen 441
points proximally away from the targeted lung area 442. Positive
pressure is applied to the proximal end of this lumen to create a
high velocity jet 443 at the distal port 441. The jet entrains gas
in the targeted area 444 to be sucked out with the jet due to the
venturi effect and thus allows for suctioning of gas but without
the risk of clogging the catheter with debris. FIG. 10k describes
another venturi system in which the tip of the catheter is
configured such that positive pressure gas ports 450 are pointed
proximally. High velocity gas exiting these ports 451 entrain gas
in the targeted area 452 to be sucked out with the jet. These
venturi configurations are especially useful in applications where
gas removal is critical to the therapy and where there is a risk of
catheter clogging if vacuum where to be used.
[0070] FIG. 11 describes a catheter exchange system wherein the
catheter is placed over a guidewire and can be disconnected. The
proximal section 480 or machine end which remains external to the
patient, includes a connector 481 for connection to a TTSV
ventilation control unit and a connector 482 for removal of the
proximal section from the distal section 483. The distal section
483 or patient end which is predominantly inside the body, includes
a receiving connector 485 for the proximal end and a slide-able
sleeve 486 for placement in the percutaneous incision. The sleeve
self-seals on the shaft of the catheter 487 and applies a slight
amount of tension to the catheter shaft to prevent inadvertent
dislodgment of the catheter from the lung. The sleeve also includes
widenings 488 on both ends to anchor it in place on both sides of
the incision. The distal section of the catheter also includes a
stretchable section of catheter tubing 489 such that during
movements of the patient's neck, the catheter length can change
without transferring undesired tension to the distal end and
inadvertently dislodging the catheter. Also included is a guidewire
490 that can be inserted and removed from a lumen 491 in the
catheter, in order to initially place the catheter into the
targeted site, or to place in the targeted site while the catheter
is being removed, for example for cleaning or replacement.
[0071] Typical diameters of the TTSV catheter depend on the lung
area being targeted. Some exemplary dimensions follow: Lobar
segment: OD=2.0-3.5 mm; Lobar subsegment: OD=1.5-2.5 mm; Lobar
sub-subsegment: OD=0.5-1.0 mm. TTSV catheter gas insufflation lumen
diameters are typically 0.25-1.0 mm and gas exhaust lumens, if
separately present, are typically comprise an area of 0.8-4.0
mm.sup.2, preferably greater than 2.0 mm.sup.2 to avoid mucous
plugging. Catheter lengths are typically 120-150 cm. Anchoring
forces are typically 1-10 psi and occlusion forces, if occlusion is
utilized, are typically 0.2-0.5 psi. Anchors and occlusive member
diameters depend on the targeted bronchial level and are up to 25
mm for main stem bronchus cannulation, 20 mm for lobar bronchus
cannulation, 12 mm for segmental bronchi and 3 mm for
sub-subsegmental bronchi cannulation when fully expanded. Proximal
entry point tensioning forces typically produce 0.5-1.5 lbs of
axial tension. The percutaneous plug is typically a soft rubber or
thermoset material such as silicone. Some examples of catheter
materials are; the shaft extrusion typically comprised of a
thermoplastic or thermoset material such as nylon, PVC,
polyethylene, PEBAX or silicone; the non-occlusive anchor typically
comprised of a stainless steel or Nitinol wire; the inflatable
occlusive member comprised of a highly compliant plastisol,
silicone or urethane; connectors typically comprised of PVC,
polysulfone, polypropylene or acrylic.
[0072] FIG. 12 describes a method and apparatus to allow the
indwelling TTSV or TTSS catheter to remain in place for extended
periods without irritating the bronchial walls and optionally to
prevent dislodgment of the catheter during movement of the neck.
FIG. 12a describes compressible loops 496 attached to the catheter
170 which can secure the catheter in place at various places along
the tracheal-bronchial tree. The loops also center the catheter so
that the catheter does not rub against the trachea 32 or airway
walls. FIGS. 12b and 12c describe a bifurcated woven sleeve 498 and
cylindrical sleeve 499 to which the catheter 170 is attached to
center the catheter in the trachea 32 and airways and to absorb any
tension applied to the distal end of the catheter.
[0073] FIG. 13 describes the TTSV Gas Control Unit comprising both
positive pressure gas delivery and negative pressure gas removal
capability, although the unit may also comprise one or the other
function. Shown on the insufflation side is a gas inlet connector
601 for a gas source, a gas reservoir or gas pressure pump 602, an
insufflation pressure regulation valve 604, an on-off control valve
603, a pilot valve 605 for relaying a desired pressure reference to
the pressure regulating valve with closed loop feedback control for
proper pressure output, an over-pressure safety relief valve 606, a
check valve 607, a pressure sensor 608, a gas outlet filter 609,
and a TTSV catheter connector 610. Shown on the suction side is a
vacuum source inlet connector 611, a vacuum reservoir or vacuum
generation pump 612, a vacuum level regulation valve 613, an on-off
control valve 614, vacuum pressure pilot pressure valve 615, a
check valve 617, pressure sensor 618 and CO.sub.2 sensor 619. A
replaceable or refillable modular cartridge of ventilation gas 620
is shown as an alternative supply, typically housing 100-500 ml of
compressed ventilation gas. For example a cartridge containing 250
ml of compressed gas pressurized at 10 psi would enable delivery of
gas at a rate of 10 ml/hour at an average output pressure of 25
cmH.sub.2O for 20 days, based on ideal gas laws, and assuming 30%
losses due to system leakage. Also shown is a power supply 621, and
electrical circuitry 622 containing the signal processing, command
center, microprocessor and imbedded software, a communication bus
for inputs and outputs to and from the valves, sensors and user
interface. An optional respiration sensor 625 is shown which
controls or synchronizes the TTSV parameters if so desired. An
optional control module 626 for controlling inflating and deflating
the occlusive member at the distal tip of the catheter, if so
equipped, is also shown. In other embodiments, the patient can use
their own suction power generated by their lung for gas removal
from the targeted area, for example by coupling their mouth to the
proximal end of the catheter.
[0074] FIG. 14 describes a kit including a sterile TTSV catheter
assembly 170, a sterile guidewire 490, a percutaneous incision and
dilitation kit 630, an access port plug 108, a Gas Control Unit
104, a gas cartridge 620, a holster for the Gas Control Unit 635,
spare battery 602 and wall charger 640, cleaning supplies 645,
instruction guide 650.
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