U.S. patent application number 11/687334 was filed with the patent office on 2007-07-05 for apparatus for lead placement on a surface of the heart.
This patent application is currently assigned to Cardiac Pacemakers, Inc.. Invention is credited to Kevin F. Hahnen, Aaron V. Kaplan.
Application Number | 20070156217 11/687334 |
Document ID | / |
Family ID | 29400281 |
Filed Date | 2007-07-05 |
United States Patent
Application |
20070156217 |
Kind Code |
A1 |
Kaplan; Aaron V. ; et
al. |
July 5, 2007 |
APPARATUS FOR LEAD PLACEMENT ON A SURFACE OF THE HEART
Abstract
The methods and apparatus for lead placement on a surface of the
heart are employed using an elongated body having proximal and
distal end portions. The body defines a lead receiving passageway
extending between a proximal inlet and a distal outlet for
receiving a lead therethrough for contact with the heart surface.
The elongated body is adapted for insertion between a pericardium
and an epicardial surface. At least a portion of the body may have
a non-circular cross-sectional shape adapted to retain the body
orientation between the pericardium and the epicardial surface.
Inventors: |
Kaplan; Aaron V.; (Los
Altos, CA) ; Hahnen; Kevin F.; (Duluth, GA) |
Correspondence
Address: |
FAEGRE & BENSON, LLP;BOSTON SCIENTIFIC PATENT DOCK
2200 WELLS FARGO CENTER
90 SOUTH SEVENTH STREET
MINNEAPOLIS
MN
55402-3901
US
|
Assignee: |
Cardiac Pacemakers, Inc.
St. Paul
MN
|
Family ID: |
29400281 |
Appl. No.: |
11/687334 |
Filed: |
March 16, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10144205 |
May 10, 2002 |
|
|
|
11687334 |
Mar 16, 2007 |
|
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Current U.S.
Class: |
607/119 ;
607/142 |
Current CPC
Class: |
A61N 2001/0578 20130101;
A61N 1/0587 20130101 |
Class at
Publication: |
607/119 ;
607/142 |
International
Class: |
A61N 1/05 20060101
A61N001/05 |
Claims
1. An apparatus for placing a lead on a surface of a human heart,
the apparatus comprising: an elongated body including a proximal
end portion and a distal end portion, the elongated body having a
length adapted to permit minimally invasive access to the heart,
the distal end portion of the elongated body defining a
longitudinal axis and having a contact surface generally parallel
to the longitudinal axis; a lead receiving passageway extending
through the elongated body to a distal outlet on the contact
surface; and a vacuum lumen extending through the elongated body
and having a proximal opening and a distal opening, wherein the
distal opening is disposed on the contact surface.
2. The apparatus of claim 1 wherein the contact surface is concave
in a direction transverse to the longitudinal axis.
3. The apparatus of claim 1 wherein the contact surface is planar
in a direction transverse to the longitudinal axis.
4. The apparatus of claim 1 wherein the distal portion of the
elongated body has an upper surface and a lower surface, and the
contact surface is on the lower surface.
5. The apparatus of claim 4 wherein the upper surface is convex in
a direction transverse to the longitudinal axis and the contact
surface is shaped to generally conform to an epicardial surface of
the heart.
6. The apparatus of claim 1 wherein the distal portion of the
elongated body has a non-circular cross section in a direction
transverse to the longitudinal axis.
7. The apparatus of claim 6 wherein the elongated body has a width
that is greater than a height of the elongated body in a direction
transverse to the longitudinal axis.
8. The apparatus of claim 1 wherein a portion of the lead receiving
passageway proximally adjacent the distal outlet extends at an
acute angle with respect to the longitudinal axis.
9. The apparatus of claim 1 further comprising a viewing lumen
extending through the elongated body, the viewing lumen having a
distal end adjacent the distal outlet.
10. The apparatus of claim 1 further comprising a steering member
for steering the distal end portion of the elongated body.
11. The apparatus of claim 10 wherein the steering member is
adapted to steer the distal end portion of the elongated body in a
plane parallel to the longitudinal axis of the elongated body.
12. The apparatus of claim 1 wherein a portion of the elongated
body is curved relative to the longitudinal axis.
13. The apparatus of claim 1 wherein the vacuum lumen and the lead
receiving passageway are non-concentric.
14. An apparatus for placing a lead on a surface of a human heart,
the apparatus comprising: an elongated body including a proximal
end portion and a distal end portion, the elongated body having a
length adapted to permit minimally invasive access to the heart,
the distal end portion of the elongated body defining a
longitudinal axis and having a contact surface generally parallel
to the longitudinal axis; a lead receiving passageway extending
through the elongated body to a distal outlet on the contact
surface; a vacuum lumen extending through the elongated body and
having a proximal opening and a distal opening, wherein the distal
opening is disposed on the contact surface; and a temporary pacing
electrode positioned on the distal end portion of the elongated
body.
15. The apparatus of claim 14 wherein the temporary pacing
electrode is positioned adjacent the distal outlet.
16. The apparatus of claim 14 wherein the temporary pacing
electrode is adapted for bipolar pacing and sensing.
17. An apparatus for placing a lead on a surface of a human heart,
the apparatus comprising: an elongated body including a proximal
end portion and a distal end portion, the elongated body having
sufficient length to allow minimally invasive access to the heart,
the distal end portion of the elongated body defining a
longitudinal axis and having a contact surface generally parallel
to the longitudinal axis; a lead receiving passageway extending
through the elongated body to a distal outlet on the contact
surface; and temporary and non-invasive means for holding the
distal outlet to the surface of the heart.
18. The apparatus of claim 17 wherein the temporary and
non-invasive means comprises a vacuum lumen extending through the
elongated body and having a proximal opening and a distal opening,
wherein the distal opening is adjacent the distal outlet.
19. The apparatus of claim 17 further comprising means for pacing
the surface of the heart adjacent the distal outlet.
20. The apparatus of claim 17 further comprising means for
electrically mapping the surface of the heart.
Description
RELATED APPLICATIONS
[0001] This is a divisional of U.S. patent application Ser. No.
10/144,205 titled, METHODS AND APPARATUS FOR LEAD PLACEMENT ON A
SURFACE OF THE HEART, filed on May 10, 2002, herein incorporated by
reference in its entirety.
BACKGROUND
[0002] This invention relates to methods and apparatus for lead
placement and other related procedures on or in connection with the
heart.
[0003] Leads are conductive devices or electrodes for temporary or
permanent contact or implantation on a heart surface. Leads are
well known in the art and commonly have an elongated shape and
include a distal end, typically with an electrode alone or in
combination with a retention member, such as spiral or barbed,
located thereon for attachment to the desired heart surface.
[0004] Leads carry electrical signals to and from the heart for a
variety of purposes. One purpose, among many, of lead implantation
is to allow pacing of the heart so as to restore the normal
sequence of mechanical contractions to the heart. By way of
example, but not limitation, leads may be placed on a surface of
the heart in conjunction with a biventricular pacemaker, which
generates a pacing signal. A proximal end of the lead is connected
to the pacemaker while the distal end of the lead is attached to
the desired heart location to carry the electrical signal to the
heart. Temporary leads may also be used to monitor heart
performance, to "map" the heart to identify conductive pathways, to
identify sources of aberrant electrical pulses and to carry out
various other diagnostic and/or therapeutic procedures.
[0005] A myriad of lead implantation sites relative to treatment of
the human heart are also possible. Leads may be placed on an outer
(epicardial) surface of the heart, implanted within the heart on an
interior (endocardial) heart surface, or placed within the coronary
sinus. The human heart is generally situated in a multi-layer
membrane or heart sac, commonly known as the pericardium. The space
between the pericardium and the outer or epicardial surface of the
heart is commonly called the pericardial space. Although it may be
technically possible to place leads on the outer surface of the
pericardium, it is preferred to place leads within the pericardial
space so as to improve the conductivity of the electrical path
between the lead and the selected heart tissue.
[0006] Current apparatus and methods for epicardial lead placement
often utilize non-minimally invasive medical procedures. These
methods may involve a large incision into the chest, thoracotomy or
medial sternotomy of a patient and/or opening of the chest cavity
for access to the heart. These procedures typically may require the
patient to be generally anesthetized, selectively intubated with
collapse of a lung. A further major disadvantage of these
procedures is that they may require a chest tube following surgery
and are often associated with a painful postoperative course.
[0007] Sub-xyphoid access to the heart surfaces has been previously
proposed by one of the inventors here in U.S. patent application
Ser. No. 09/315,601 filed May 20, 1999 and is incorporated by
reference herein. One potential difficulty which needs to be
overcome when using the sub-xyphoid route for lead placement is the
need for a substantial distal portion of the lead to be
orthogonally disposed relative to the selected lead placement site
in order to adequately attach the lead on the heart surface. In
other words, it has been previously considered that the incident
angle of approach of the lead placement apparatus should be
disposed at a nearly perpendicular angle relative to the heart
surface in order to position the distal outlet in a desired
direction for lead placement. Because the angle of approach is so
large, it requires a large working volume within the pericardial
space. The working space required by the apparatus thus displaces a
greater amount of cardiac tissue, which can increase the risk of
complications during and after surgery. Therefore, there is a need
for apparatus and methods for lead placement which avoid these
shortcomings.
[0008] Several devices and methods for minimally invasive access to
the epicardial surface of the human heart have been described in
co-pending application Ser. Nos. 09/315,601 filed May 20, 1999, and
09/397,392 filed Sep. 16, 1999, both of these applications are
hereby incorporated by reference in the present application.
[0009] Another drawback of current lead placement apparatus and
methods is that they do not typically incorporate the ability to
navigate over the surfaces of the heart for optimal lead placement.
In one aspect, it would be desirable to provide an apparatus which
permits temporary pacing of the heart so as to determine the
optimal lead placement site prior to attachment of the lead to the
heart surface. Pacing by temporary electrodes or leads prior to
attachment of a permanent lead better ensures that the lead is
properly attached to the desired heart location. In another aspect,
it would be desirable to have a lead placement apparatus which
prevents lead deposition in proximity to a coronary artery. Since
coronary arteries surround the exterior of the heart, there is a
danger that lead implantation could pierce the artery, resulting in
possible bleeding into the pericardial space which may lead to
hemodynamic compromise and collapse. Placement of an epicardial
lead onto a coronary artery may occlude the artery resulting in
infarction of the myocardium perfused by that artery. So, it would
be desirable to provide a lead placement apparatus which has the
ability to sense when the lead placement apparatus is unduly close
to a coronary artery.
[0010] Current lead placement devices also do not provide relative
positioning of the distal end of the device so as to orient the
distal end in the desired direction for lead placement. Since the
surface of the heart is not flat or uniform, the ability to
position the distal end against the desired lead placement location
is also desirable. Even once the lead placement site is located,
the lead placement apparatus desirably should facilitate lead
removal from the apparatus.
[0011] Accordingly, it is a general object of the present invention
to provide a minimally invasive method and apparatus for placing a
lead on a surface of the heart.
[0012] Another object of the present invention is to provide for an
apparatus and method for lead placement, which apparatus has a
geometry specifically suited for lead placement.
[0013] It is the object of another aspect of the present invention
to provide a method and apparatus for temporary pacing of the heart
prior to lead placement or in connection with mapping the
conductive pathways of the heart tissue.
[0014] It is another object of the present invention to provide a
method and apparatus for detecting proximity to the coronary
arteries so as to avoid placement of the lead on or near a coronary
artery.
[0015] It is a further object of the present invention to provide a
method and apparatus which provides a distal end of the apparatus
which is adapted to move in at least one plane when force is
applied to the apparatus.
[0016] It is yet another object of the present invention to provide
a method and apparatus having an expandible member to hold the
apparatus adjacent the epicardial surface for lead placement.
[0017] A further object of the present invention is to provide a
lead placement apparatus which facilitates lead removal.
[0018] A yet further object of the present invention is to provide
a minimally invasive lead placement apparatus having a distal end
portion which has an acute angle relative to the longitudinal axis
for lead placement.
[0019] These objectives are provided to illustrate the context of
the present invention and are not an exclusive listing of the
objectives or benefits of the present invention. Not all of these
objectives are necessarily met in each apparatus or method of the
present invention. Apparatus or methods of the present invention
may meet or address one or more, but less than all, of these
objects or other objects or benefits of the invention apparent in
other parts of this description. Therefore, these objectives are
not presented for, and should not be used for, the purpose of
limiting the scope of the invention as set forth in the appended
claims.
SUMMARY
[0020] The features and objects of the present invention will
become apparent upon reference to the following detailed
description and attached drawings. Generally speaking, in
accordance with one aspect of the present invention, the apparatus
includes an elongated body or sheath having a proximal end portion,
a distal end portion, and defines a passageway having a proximal
inlet and a distal outlet for receiving a lead or conductive
member. The distal outlet is generally located adjacent the distal
end portion of the body.
[0021] The present invention is particularly well suited for
providing a method and apparatus for placing a lead on a surface of
the heart, where a substantial length of the body is adapted for
insertion between a pericardium and an epicardial surface and the
body is adapted for directional control by the user to position the
distal outlet at a desired location between the pericardium and the
epicardial surface.
[0022] At least a portion of the elongated body also may have a
non-circular shape which is adapted to retain the body at a
selected angular orientation between the pericardium and the
epicardial surface. The non-circular shape may be comprised of
convex, concave and planar surfaces, as will be described below.
The body may further include a plurality of lumens or passageways
for receiving, connecting to, or accommodating a variety of
elements such as, for example, a vacuum, an inflation source, an
irrigation source, a guide wire, an endoscope, a fiberoptic viewing
device, temporary pacing electrodes, a Doppler sensor, a steering
member, an expandible member, a flexible or malleable
shape-retaining wire, or other like elements for facilitating lead
placement in addition to other purposes which will be apparent to
one skilled in the art. It is submitted that there are numerous
combinations of all or some of these elements and that the
combinations shown and described are by way of example and are not
intended to limit the scope of the claimed invention.
[0023] Several mechanisms may be utilized in order to position the
distal outlet of the body against the selected lead placement site.
One way to move the distal end portion of the body is accomplished
by employing at least one steering member extending through the
elongated body having a distal and proximal end. The steering
member moves when force is applied to the proximal end of the
steering member. The force may be tensile, compressive or
torsional, or a combination thereof. A steering collar can be
positioned on the body spaced from the distal end portion to
control one or more of the steering members. The steering collar is
movable to supply tensile, compressive or torsional movement to the
steering members. Movement of the steering members allows movement
of the distal end portion of the body in at least one plane
although movement in more than one plane is also possible.
[0024] In addition to the steering members, other ways to position
the distal end portion of the body utilize a vacuum lumen, an
expandible member, and/or a flexible or malleable element. The
vacuum lumen may extend through the body between the proximal end
portion, which is connected to a vacuum source, and the distal end
portion which defines a distal opening of the vacuum lumen so as to
create a suction force at the distal outlet and maintain the distal
outlet biased against the selected lead placement site. Biasing of
the distal outlet against the selected site can also be performed
by selective expansion of the expandible member which is carried by
the body and disposed in proximity to the distal outlet. One or
more expandible members can be utilized and are adapted to expand
after insertion of the body into the pericardial space and, by way
of example but not limitation, the expandible member may include a
balloon and inflation lumen, which fluidly communicates between the
balloon and an inflation source, an expandible cage-like member or
members, or the like. The expandible members may be mounted at the
distal end in an eccentric or concentric fashion. The body may
include at least one flexible or malleable wire which preferably,
but not exclusively, extends through at least a portion of the body
extending from the distal end portion and the flexible wire is well
suited to retain a desired shape corresponding to the surface of
the selected lead placement site so as to orient the distal end
portion of the body for lead placement. Any of the aforementioned
ways, either by themselves or in any combination thereof, as well
as others may be employed to position the distal outlet against the
selected lead placement site.
[0025] The present invention also provides a method and apparatus
having a body including at least one temporary pacing electrode
disposed in proximity to the distal end portion for contact with
the surface of the heart. The temporary pacing electrode may be
used in connection with placing a lead on a surface of a human
heart and/or allow for the conductive pathways of the heart to be
mapped for a variety of purposes. A conductor extends through the
elongated body from the electrode to the proximal end portion of
the body for attachment to an electric pacing signal source. The
temporary pacing electrode is adapted to pace the heart by contact
with selected one of a pericardial and epicardial surface. The
temporary pacing electrode may be fixed at the distal end or
removably inserted through the body.
[0026] In another aspect of the invention, the body of the lead
placement apparatus defines a passageway which includes at least
one outlet adapted to receive an elongated guide wire and a lead.
The passageway has a lead outlet which is sufficiently sized to
allow passage of the lead for attachment to the surface of the
heart. The lead outlet tapers to a guide wire outlet which is
distally located on the body in relation to the lead outlet. The
guide wire outlet is sufficiently sized and oriented to allow
passage of the guide wire forward of the distal end of the body and
to deflect the lead to exit at an angle relative to the
longitudinal axis of the body for engagement with heart tissue.
[0027] The present invention also discloses a lead placement
apparatus and method for sensing the presence of a coronary artery
so as to avoid placement of the lead into a coronary artery. The
body includes a Doppler sensor disposed in proximity to the distal
outlet and the Doppler sensor is in communication with an
operator-readable output device to indicate the presence of a
coronary artery in proximity to the distal outlet.
[0028] The present invention further provides an improved
epicardial lead construction for ease of placement on an epicardial
surface of the heart.
BRIEF DESCRIPTION OF THE DRAWINGS
[0029] FIG. 1 is a side view of a first embodiment of a lead
placement apparatus of the present invention.
[0030] FIG. 2 is a side view of a second embodiment of a lead
placement apparatus of the present invention.
[0031] FIG. 3 is a sectional view of a distal end portion of the
lead placement apparatus.
[0032] FIG. 4 is a bottom view of the distal end portion of the
lead placement apparatus.
[0033] FIGS. 4A-4C are sectional views of the distal end portion
along the lines indicated in FIG. 4 and illustrating the
non-circular cross-sectional shape of at least a portion of the
body.
[0034] FIG. 5A is a sectional view of the distal end portion,
similar to FIG. 4C, including a single steering member.
[0035] FIG. 5B is a sectional view of the distal end portion,
similar to FIG. 4C, including a dedicated guide wire lumen.
[0036] FIG. 5C is a sectional view of the distal end portion,
similar to FIG. 4C, including a flexible element and having an
alternate non-circular cross-sectional shape.
[0037] FIG. 5D is a sectional view of the distal end portion,
similar to FIG. 4C, including an inflation lumen and having another
non-circular cross-sectional shape.
[0038] FIG. 5E is a sectional view of the distal end portion,
similar to 4C, including an endoscope lumen and a fluid delivery
lumen and illustrating yet another non-circular cross-sectional
shape.
[0039] FIG. 6A is a sectional view, similar to FIG. 3, showing a
third embodiment of a lead placement apparatus having a monopolar
temporary pacing electrode.
[0040] FIG. 6B is a bottom view of the embodiment shown in FIG.
6A.
[0041] FIG. 6C is a sectional view along line 6C-6C in FIG. 6B.
[0042] FIG. 7 is a side view of a fourth embodiment of the lead
placement apparatus having an expandible member.
[0043] FIG. 7A is a sectional view along line 7A-7A in FIG. 7.
[0044] FIG. 8 is a perspective view of the distal end portion of a
fifth embodiment of a lead placement apparatus having an expandible
member shown in an unexpanded condition.
[0045] FIG. 9 is a side elevation view, illustrating the lead
placement apparatus of FIG. 8 between the pericardium and
epicardial surface of a heart with the expandible member shown in
an expanded condition.
[0046] FIG. 10 is a perspective view of an alternate expandible
member which extends fully circumferentially relative to the lead
placement apparatus.
[0047] FIG. 11 is a perspective view, similar to FIG. 8, showing
another type of an expandible member.
[0048] FIG. 12 is a side elevation view, similar to FIG. 9, showing
the expandible member of FIG. 11 in situ between the pericardium
and epicardial surface of a heart.
[0049] FIG. 13 is a perspective view showing a further expandible
member which extends fully circumferentially relative to the lead
placement apparatus.
[0050] FIG. 14 is an anterior plan view of a patient's chest
showing an incision via the sub-xyphoid region.
[0051] FIGS. 14A-14D are sectional elevation views of a patient's
chest showing access to the pericardial space via a sub-xyphoid
approach.
[0052] FIG. 15 is a longitudinal cross-section of the distal end
portion of the lead placement apparatus taken along line 15-15 of
FIG. 17, showing insertion of a guide wire into the pericardial
space.
[0053] FIG. 16 is a longitudinal section taken along line 1616 of
FIG. 17 which shows insertion of a lead into the pericardial
space.
[0054] FIG. 17 is a transverse sectional view of the lead placement
apparatus of FIGS. 15 and 16.
[0055] FIG. 18 is an anterior plan view of the patient's heart
which shows implantation of a lead and connection of the lead to a
pacer signal source.
[0056] FIG. 19 is a perspective view of a sixth embodiment of the
lead placement apparatus showing a portion of the apparatus being
normally curved relative to the longitudinal axis.
[0057] FIG. 20 is a perspective view of a seventh embodiment of the
lead placement apparatus showing a normally straight portion of the
apparatus being curved relative to the longitudinal axis as the
result of a curved insertion sleeve.
[0058] FIG. 21 is a perspective view of the lead placement
apparatus showing movement between a normally curved position and a
straight position by applying force to a steering wire.
[0059] FIG. 22 is a perspective view of the lead placement
apparatus showing movement between a normally straight position and
a curved position by applying force to a steering wire.
[0060] FIG. 23 is a perspective view of an eighth embodiment of the
lead placement apparatus.
[0061] FIG. 23A is a perspective view of an alternate temporary
pacing electrode for insertion into the apparatus shown in FIG.
23.
[0062] FIG. 23B is a perspective view of a lead for insertion into
the apparatus shown in FIG. 23.
[0063] FIG. 24 is a perspective view of a ninth embodiment of the
lead placement apparatus having a flexible or malleable
element.
[0064] FIG. 25 is an enlarged transverse sectional view of a tenth
embodiment of the lead placement apparatus which is adapted to
allow removal of a lead in a direction transverse to the
longitudinal axis of the apparatus.
[0065] FIG. 26 is a longitudinal sectional view of the apparatus of
FIG. 25 including a lead.
[0066] FIG. 27 is a side view of an eleventh embodiment of the lead
placement apparatus which allows lead removal in a transverse
direction to the longitudinal axis of the apparatus.
[0067] FIG. 28 is an end view of the embodiment shown in FIG.
27.
[0068] FIG. 29 is a side view of a twelfth embodiment of the lead
placement apparatus which allows removal of the lead in a
transverse direction to the longitudinal axis of the apparatus.
[0069] FIG. 30 is a sectional view along line 30-30 of FIG. 29.
[0070] FIG. 31 is a perspective view of a thirteenth embodiment of
the lead placement apparatus which allows removal of the lead in a
transverse direction to the longitudinal axis of the apparatus.
[0071] FIGS. 32A-32B are end views of the embodiment shown in FIG.
31 showing closed and open positions, respectively.
[0072] FIG. 33 is a perspective view of a fourteenth embodiment of
the lead placement apparatus which allows removal of the lead in a
transverse direction to the longitudinal axis of the apparatus.
[0073] FIG. 34 is a sectional view along line 34-34 in FIG. 33.
[0074] FIG. 35 is a longitudinal sectional view of a fifteenth
embodiment of the lead placement apparatus which allows removal of
the lead in a transverse direction to the longitudinal axis of the
apparatus.
[0075] FIG. 36 is a side view of the embodiment shown in FIG. 35
showing removal of a longitudinally disposed portion of the
apparatus.
[0076] FIG. 37 is a partial transverse sectional view of the
embodiment shown in FIGS. 35-36.
[0077] FIG. 38 is a perspective view of a sixteenth embodiment of
the lead placement apparatus which allows removal of the lead in a
transverse direction to the longitudinal axis of the apparatus.
[0078] FIG. 39 is a section view along line 39-39 of FIG. 38.
[0079] FIG. 40 is a side view of a seventeenth embodiment of the
lead placement apparatus which allows removal of the lead in a
transverse direction to the longitudinal axis of the apparatus.
[0080] FIG. 40A is a sectional view along line 40A-40A of FIG.
40.
[0081] FIG. 41 is a side view of the apparatus of FIG. 40 in an
open position.
[0082] FIG. 41A is a sectional view of along line 41A-41A of FIG.
41.
[0083] FIG. 42 is a side view of an epicardial lead having an
angled distal end portion.
[0084] FIG. 42A is a sectional view along line 42A-42A of FIG.
42.
[0085] FIG. 43 is a side view of another epicardial lead having a
curved distal end portion.
[0086] FIGS. 44-45 are side views of an epicardial lead having a
distal end portion which is adapted to move between straight and
angled positions, respectively.
[0087] FIG. 45A is a sectional view along line 45A-45A of FIG.
45.
[0088] FIGS. 46-47 are side views of other epicardial leads having
an angled distal end portion.
[0089] FIG. 48 is a side view of another epicardial lead having a
distal end portion which is adapted to move between straight and
angled positions.
[0090] FIG. 49 is a side view of an epicardial lead including a
steering member.
[0091] FIG. 50 is a side view of an epicardial lead having an
alternate distal section.
[0092] FIG. 51 is a side elevation view of a prior art epicardial
lead placing the lead on a surface of the heart.
[0093] FIG. 52 is a side elevation view of the epicardial lead of
the present invention placing the lead on a surface of the
heart.
[0094] FIG. 53 a side view of a further embodiment of a lead
placement apparatus of the present invention with portions of the
apparatus shown in section.
[0095] FIG. 54 is a plan view of the lead placement apparatus of
FIG. 53.
[0096] FIG. 55 is a sectional view along line 55-55 of FIG. 53.
[0097] FIG. 56 is an enlarged partial longitudinal sectional view
of the lead placement apparatus of FIG. 53 with the distal end
portion shown in a deflected configuration.
[0098] FIG. 57 is a side view of a still further embodiment of a
lead placement apparatus having an expandible member with the
distal end portion shown in section.
[0099] FIG. 58 is an enlarged partial longitudinal sectional view
of the distal end portion of the lead placement apparatus in FIG.
57.
[0100] FIG. 59 is a partial longitudinal sectional view of the lead
placement apparatus in FIG. 57 showing the expandible member in an
enlarged configuration.
[0101] FIG. 60 is a side view of the lead placement apparatus in
FIG. 53 with portions of the apparatus shown in section showing
insertion of a guiding or trocar device.
[0102] FIG. 60A is a cross sectional view along line 60A-60A in
FIG. 60.
[0103] FIG. 61 is a side view of the lead placement apparatus,
similar to FIG. 60, showing insertion of a Doppler sensor.
[0104] FIG. 62 is a side view of the lead placement apparatus,
similar to FIG. 60, showing insertion of a lead.
DETAILED DESCRIPTION
[0105] The present invention provides methods and apparatus for
placing a lead on a surface of a human heart. Although the
invention will be described by way of example but not limitation in
relation to epicardial lead placement, placement of the lead on
other heart surfaces is also possible. Such heart surfaces may also
include the pericardium and the endocardial surface in addition to
the epicardial surface. The manner in which the lead is placed on
the heart surface may also vary. By way of example but not
limitation, the lead may be implanted or embedded into the surface
using a retention member or fastener which penetrates beneath the
surface. Different types of retention members may be utilized and
it is not intended for the present invention to be limited only to
those retention members shown in the drawings since it is realized
that many variations may be used to effectuate lead retention
without departing from the present invention. Moreover, the lead
may be placed on the heart surface for either temporary or
permanent use, as needed.
[0106] As shown in FIG. 1, a first embodiment of a lead placement
apparatus 10 of the present invention includes an elongated body 12
and defines a longitudinal axis 13. The body 12 includes a proximal
end portion generally at 14 and a distal end portion generally at
16. The body 12 defines a lead receiving passageway 18 which
extends between a proximal inlet 20 and distal outlet 22. The lead
receiving passageway 18 is adapted and suitable to receive a lead
for attachment to the surface of the heart. The lead is shown, by
way of example, in FIG. 16 which will be described below. At the
proximal end portion 14 of the body 12, a handle 24 may be
provided. A preferred approach utilizes a sub-xyphoid approach to
place the lead on a heart surface. Other approaches may be utilized
without departing from the scope of the claimed invention, such as,
for example, intercostal, intravenous and other minimally invasive
approaches as well as more invasive approaches, such as open chest
procedures.
[0107] The elongated body 12 preferably has sufficient length so as
to allow insertion of at least the distal end portion 16 of the
body from a sub-xyphoid transcutaneous access opening to the area
between the pericardium and the epicardial surface and into a space
which is commonly referred to either as the pericardial space. The
length of the body will depend on which medical approach is used to
gain access to the heart surface. Importantly, the length of the
body should be such that the handle 24 remains outside of the
patient while the medical procedure is performed so as to allow
greater control over the lead placement apparatus. By way of
example but not limitation, the length L of the body 14 between the
proximal inlet and the distal outlet 22 has a length and a range of
10 cm to 40 cm, preferably 20 cm to 30 cm where a sub-xyphoid
approach is used, so that the proximal inlet 20 is located outside
of the patient.
[0108] In FIG. 1 the proximal inlet 20 is disposed at generally the
proximal end portion 14 of the body 12, although it is spaced from
the proximal tip end of the handle. The length L of the body 12
allows extension of the distal end portion 16 into the pericardial
space while, at the same time, allowing the proximal inlet 20 to
extend outside into the pericardial space and, preferably, outside
of the incision access location into patient's body. In this way,
the proximal inlet 20 is accessible to allow insertion of the lead
therein. It is also possible to position the proximal inlet at
other longitudinal positions along the body 12 as is indicated in
FIG. 2 in an alternate apparatus 26, with like parts being shown
with like numbers, except that the proximal inlet 28 is positioned
at the most proximal end of the handle 24. The apparatus 26
similarly has a length which is sized to allow insertion of the
distal end portion 16 into the pericardial space and access to the
handle 24 and proximal inlet 20 from the outside of the incision
access location.
Non-Circular Shape
[0109] Turning to FIGS. 4-4C, at least a portion of the elongated
body 12 may have in certain, but not all embodiments of the present
invention, a non-circular shape, so described because it has a
cross-section which is non-circular as best seen in FIGS. 4 and 5.
The non-circular shape may appear in a myriad of different forms,
some of which will be shown and described below, but other
non-circular shapes are also possible without departing from the
present invention. The non-circular shape is associated with at
least a portion of the body, preferably, the portion of the body
which is inserted into the pericardial space. For example, the
non-circular shape extends along the body 12 between the proximal
inlet 20 and the distal outlet 22 in FIG. 1 or between a portion
thereof. In the most preferred form, the portion of the body 12
which contacts the heart surface such as the distal end portion 16
has a non-circular shape. As shown in FIGS. 3-4C, the non-circular
shape of the body 12 is generally constant along the body except
near the distal end portion 16 where the body gradually tapers.
[0110] In FIG. 4C the non-circular shape includes an upper surface
32 which is convex and a lower surface 34 which is planar. So the
cross-sectional shape of the non-circular portion 30 in FIG. 4C has
a "D" configuration. It is contemplated that the lower surface 34
faces the heart surface in which lead placement is desired and the
upper surface 32 generally faces away from the desired lead
placement site, although other orientations are also possible. As
shown in FIGS. 3 and 4B the distal outlet 22 may be defined in the
lower surface 34 near the distal end portion 16 of the body. So
when the distal outlet 22 is placed adjacent the desire lead
placement site, the lead can be advanced from the outlet opening in
the lower surface 34 and directed at the heart tissue. It is
realized that other locations of the distal outlet are possible
without departing from the present invention.
[0111] As is illustrated best in FIG. 4C, the portion of the body
with the non-circular shape preferably has a width, generally
indicated at W, which is greater than its thickness, generally
indicated at T. When the body is inserted into the pericardial
space, the width of the body 12 is oriented in a generally parallel
relationship to the heart surfaces. Relative to FIG. 4C, the lower
surface 34 is disposed adjacent the epicardial surface and at least
a portion of the upper surface 32 is disposed adjacent the
pericardium. Likewise, the thickness of the body 12 is oriented in
a generally perpendicular relationship with the heart surfaces, so
the non-circular shape of the body attributes a slim profile when
inserted into the pericardial space. Also, the working space
existing within the pericardial space is more efficiently utilized,
and displacement between the epicardial surface and pericardium is
minimized when the body is inserted into the pericardial space. It
can further be said that the non-circular shape of the body tends
to retain the body at a selected angular orientation between the
pericardium and the epicardial surface and prevents unplanned
rotation of the body about its own axis. This assists in orienting
the distal outlet in the desired direction so that it is pointed
toward the heart surface.
[0112] FIGS. 5A-5E illustrate variations in the body 12 and like
parts will be indicated with like numbers followed by a letter
designation of A-E, as appropriate, which corresponds to the
appropriate figure. FIGS. 5A and 5B show bodies, 12A and 12B,
respectively, which are shaped similarly to the non-circular shaped
body 12 in FIG. 4C, except that the internal arrangement of lumen
is varied, as will be described later. FIG. 5C illustrates an
alternate non-circular shape of a body 12C having an upper surface
32C and a lower surface 34C which are both convex so as to
generally define an oval or eccentric shape. FIG. 5D illustrates
another alternate non-circular shape of the body 12D having an
upper surface 32D which is convex and a lower surface 34D which is
concave. FIG. 5E illustrates a body 12E having an elongated oval
shape where the upper and lower surfaces define substantially
planar top and bottom portions which are joined by curved edge
portions. The major axis of the oval is oriented along the width
and the minor axis is oriented along the thickness.
[0113] As can be seen during insertion of the body 12 into the
pericardial space using these alternate shapes, the upper surface
32 will be in contact with the pericardium and the lower surface 34
which includes the distal outlet of the lead receiving passageway
will generally be in contact with the epicardial surface. As the
non-circular portion generally has a width which is greater than
its thickness and provides a relatively slim profile, insertion of
the body into the pericardial space is facilitated. Also, the
distal outlet 22 of the lead receiving passageway 18 is preferably
located in the lower surface 34, which faces the epicardial
surface. The non-circular shapes shown in the figures are by way of
example but not limitation since other combinations may be
utilized.
[0114] Turning back to FIGS. 3-4C, the distal end portion 16 of the
body 12 illustrated there gradually narrows from a more proximal
portion of the body. In particular, the body 12 narrows from the
view shown in FIG. 4C to the successive view 4B and then 4A as the
body extends to the distal end portion 16. Although the body is
successively thinner in FIGS. 4A and 4B, than in FIG. 4C, the body
12 may retain a non-circular shape. FIGS. 4A and 4B also generally
retain the relative proportions of the body where the width which
is greater than the thickness.
Guide Wire Outlet
[0115] FIGS. 3-4B also illustrate a guide wire outlet 36 which is
formed in the lower surface 34 of the body at the distal end
portion 16. The guide wire outlet 36 is formed distally relative to
the lead outlet or distal outlet 22 and, as shown in FIGS. 3 and 4,
the guide wire outlet 36 is in communication with the distal outlet
22, and connects to the lead receiving passageway 18.
[0116] As shown in FIG. 3, a guide wire 38 is received by the lead
receiving passageway 18 and is inserted from a more proximal
portion of the body 12, such as from either of the proximal inlets
20 and 28 in FIGS. 1 and 2, respectively. The guide wire 38 has a
proximal end 40 and a distal end 42 which extends forwardly, or
distally, through the guide wire outlet 36.
[0117] In FIGS. 3-4B, the guide wire outlet 36 is generally defined
as a channel extending longitudinally from the distal outlet 22 in
the forward direction, similar to the entrance to an igloo. The
guide wire outlet 36 is sufficiently sized and oriented to allow
passage of the guide wire but prevent passage of the lead. As shown
in FIGS. 3-4C, the guide wire outlet 36 is sized smaller than the
lead outlet and longitudinally oriented in order to avoid extension
of the lead beyond the distal end portion 16 of the body.
[0118] During use the distal end 42 of the guide wire extends
forwardly of the distal end portion 16 so as to guide the apparatus
10 to the selected lead placement site. The guide wire also may
bisect the tissue so as to provide a clear working space for lead
placement. The guide wire may be removed from the body and
successively thicker guide wires may be inserted. The lead
receiving passageway 18 may be sized so that it is adapted to
receive the guide wire and the lead during use or, alternatively,
the guide wire may be removed from passageway 18 prior to lead
insertion. After proper placement of the distal end is confirmed,
the lead may be inserted. When the distal tip of the lead engages
the end of the body, the curved inner surface deflects the lead
downwardly through the distal outlet 22.
Steering Members
[0119] FIGS. 4 and 4C also illustrate steering members 52 disposed
within the body 12. The steering wires 52 have a distal end 54 and
a proximal end 56. The distal end 54 of the steering members is
located at a position at or near the distal end portion 16 of the
body and extends in a proximal direction towards the proximal end
portion 14 of the body. The proximal end 56 of the steering members
may extend from the proximal end portion 14 of the body 12 in a
similar manner as described relative to the vacuum lumen 44 or it
may extend to any of several intermediate positions of the body.
The steering wires 52 may be operatively connected to a steering
collar 58, as shown in FIGS. 1 and 2, which is disposed at a more
proximal portion of the body 12 adjacent the handle 24 and
accessible to the doctor.
[0120] The steering members 52 are made of a suitable material
having an elongated shape such as wire, fiber, filament, surgical
tape or the like although other materials and forms are possible
without departing from the present invention. The steering member
may include one or more separate members as shown in FIGS. 4 and
4C, which illustrates two steering members. By pulling on one
member and pushing (or at least not pulling) the other, the distal
end portion can be deflected in the desired direction. By reversing
this action, the tip may be deflected in the opposite
direction.
[0121] The body 12, and in particular, the handle 24 or steering
collar 58 may include, various control elements such as levers,
buttons, switches or the like to vary the application of force, the
degree of curvature, and the direction of movement. The applied
force may be tensile, compressive or rotational or any combination
thereof. Tension and compression may be applied directly or
indirectly to the steering member by pulling or pushing the
steering member at any position along its length whereas rotation
occurs by directly or indirectly twisting the steering member. The
steering members may be used in combination with the vacuum lumen
discussed above or, alternatively, in lieu of the vacuum lumen so
as to orient the distal outlet in the desired direction for lead
placement.
[0122] In the embodiment shown in FIGS. 4 and 4C, the steering
members are each positioned on one side of the body and extend
longitudinally relative to the body. So that within a first plane,
tensile force applied to the proximal end 56 of the left steering
member 52 in FIG. 4C will move the distal end portion 16 to the
left. Similarly, tensile force applied to the proximal end of the
right steering member in FIG. 4C will move the distal end portion
to the right.
[0123] As mentioned previously, other types of forces or a
combination thereof may be applied to the steering member either
directly or indirectly. Also, force can be applied to the steering
member so as to move the distal end portion 16 of the body in more
than one plane. The resultant movement of the distal end portion 16
will depend on the number and location of steering members disposed
within the body as well as the magnitude and type of forces
applied. It is realized that one or more steering members may be
positioned at different locations and orientations within the body
so as to effectuate the desired movement of the distal end portion.
Other combinations are possible without departing from the present
invention.
[0124] By way of example but not limitation, FIGS. 5A and 5B
illustrate alternate bodies 12A and 12B, respectively, each having
a single steering member 52A and 52B, respectively. In FIG. 5A the
steering member 52A is disposed in an upper left position. In FIG.
5B the steering member 52B is disposed in a lower right position.
So, force applied either directly or indirectly to either steering
member will cause deflection of the distal end portion 16.
[0125] In addition, movement of the steering member may increase or
decrease the curvature of the distal end portion relative to the
remainder of the body as illustrated in FIGS. 21 and 22. Turning
briefly to FIGS. 21-22, these figures illustrate other aspects of
the steering members of the present invention. In FIG. 21, a body
60 includes a steering member 52 which extends through the body to
the distal end portion 16. The body 60 generally defines a
longitudinal axis 62 and at least the distal end portion 16 of the
body is curved relative to the axis when normally positioned and
not acted upon by any force. The body may be curved, for example,
to an angle between 10 degrees and 80 degrees relative to the
longitudinal axis 62 and preferably between approximately 30 and 60
degrees. The normal or at rest position of the body is illustrated
in solid lines and dashed lines represent a position of the body
after force has been applied either directly or indirectly to the
steering member. The force, indicated at 64, may be tensile,
compressive or rotational or a combination thereof. When force is
applied to the steering member 52, the distal end portion 16 moves
to a less curved position as indicated by dashed lines.
[0126] An alternate body 66 is illustrated in FIG. 22, which
likewise has a steering member 52 extending to the distal end
portion 16. In this embodiment the distal end portion 16 is
normally positioned in alignment with the longitudinal access 62
and force applied to the steering member 52 moves the distal end
portion 16 of the body from the normally aligned straight position
to a curved position relative to the longitudinal axis. It is
realized that any type of force may be used to move the distal end
portion of the body in one or more planes so that the distal end
portion of the body may be curved relative to the longitudinal axis
in one or more planes in the range approximately of 10 degrees to
80 degrees.
[0127] Turning also to FIGS. 19 and 20, other steering features may
be utilized in the present invention. FIGS. 19 and 20 show a least
a portion of a body which is curved relative to a longitudinal axis
200. In FIG. 19 a body 202 having a distal end portion 204 is
normally curved relative to the longitudinal axis 200 at the distal
end portion. The body is made of a flexible or deformable material
such as a polymer or plastic or may be made of a rigid material
which is adapted to articulate. A distal outlet 206 is defined in
the distal end portion for extension of the lead therethrough. The
body 202 is slidably received in an elongated sleeve 208. The
sleeve 208 has a rigid or semi-rigid, cylindrical shape and defines
an inner lumen 210 which is sized sufficiently large to receive the
body 202 for slidable movement. The sleeve diameter is slightly
larger than the diameter of the body and preferably sized so as to
fit snugly over the body and prevent incidental moving of the
sleeve during insertion of the body into the pericardial space,
although it is preferred that there be clearance between the
proximal end of the sleeve and the proximal end of the body so as
to permit axial movement of the sleeve on the body. The sleeve
preferably has sufficient length so that during insertion of the
sleeve and body into the pericardial space the sleeve extends from
the distal end 206 of the body to a more proximal portion of the
body which is located outside of the pericardial space for
accessibility by the operator.
[0128] In FIG. 19, the sleeve 208 has a linear configuration so
that when the sleeve is moved in a position where the sleeve 208 is
positioned around the distal end 204 of the body, the body is
temporarily deformed from its normally curved position to a
straight configuration, which may be desired during introduction of
the body initially into the patient's chest. When the body is
inserted into the pericardial space, the sleeve 208 may be moved or
retracted proximally relative to the distal end 204 so as to allow
the portion of the body 202 which extends distally on the sleeve to
resume its normally curved configuration, which may be at any angle
between 10 degrees and 80 degrees relative to the longitudinal
axis. Selective retraction of the sleeve may permit greater or
lesser curvature of the body--depending on the length of the body
that extends beyond the distal end of the sleeve.
[0129] FIG. 20 illustrates an alternative sleeve 212 having a
curved portion relative to the longitudinal axis 200. An inner bore
214 sized to receive a body 216. A distal end 218 of the sleeve is
curved relative to the longitudinal axis 200. The sleeve in FIG. 20
maintains the body 216 in a curved orientation relative to the
longitudinal axis where the body, instead of being normally curved,
may be normally straight. Then as the body 216 extends from the
distal end 218 of the sleeve the distal end of the body will
maintain an orientation in the direction pointed by the distal end
of the sleeve, or in other words, which is in coaxial alignment
with the distal end 218 of the sleeve. The angle of curvature of
the sleeve may be between 10 degrees and 80 degrees, for
example.
Plurality of Lumen
[0130] FIGS. 1-5E illustrate a plurality of lumens or passageways
defined by the body 12 and these lumens or passageways are adapted
to receive or accommodate a myriad of elements. These lumens or
passageways may have a variety of different orientations although
they generally extend between a distal end or opening and a
proximal end or opening. FIGS. 5A-5E illustrate, in cross sectional
views, various positions and combinations and orientations of the
passageways within the lead placement apparatus, and are intended
to be exemplary and not exclusive.
[0131] Turning to more particular embodiments, in FIGS. 1-4 and 4C,
the body 12 defines a vacuum lumen 44, which extends between a
proximal opening 46 and a distal opening 48. The proximal opening
46 is located at the proximal end portion 14 of the body. FIG. 1
illustrates the proximal opening 46 in the form of a rearwardly
extending tube for attachment to a suction port of a vacuum source
50. In FIGS. 3 and 4, the distal opening 48 of the vacuum lumen 44
is formed as an annulus or C-shaped configuration partially around
the distal outlet 22. This annulus provides a suction force at the
distal outlet so as to help hold the distal outlet against the
heart surface. Of course, other locations of the vacuum lumen
distal opening are possible corresponding to alternate positions on
the distal outlet 22. Alternate positions of the vacuum lumen 44 in
the body are shown in FIGS. 5A-5C, as indicated by corresponding
numbers 44A-44C.
[0132] FIGS. 5B-5E briefly illustrate other devices which may be
introduced through the body and the associated lumen. For example,
the body may include passageways, such as a guide wire lumen 68
(FIG. 5B), a lumen for an elongated flexible or malleable element
70 (FIG. 5C), an inflation lumen 74 (FIG. 5D), an endoscope lumen
76 (FIG. 5E), a fluid delivery lumen 78 (FIG. 5E), and a lumen for
a Doppler sensor 80 (FIG. 5E). Each of these will be described in
turn with reference to the appropriate figures.
[0133] FIG. 5B illustrates a dedicated guide wire lumen 68 which
extends between a guide wire inlet and a guide wire outlet. It is
contemplated that the guide wire inlet can be located on a proximal
portion of the body 12B. By way of example, but not limitation, the
guide wire inlet may be positioned on the body as previously
described relative to the proximal inlet 20 in FIGS. 1 and 2. Also,
in a manner similar to the previously described guide wire outlet
36 in FIGS. 3 and 4, the guide wire outlet of the dedicated guide
wire lumen 68 is preferably disposed generally in proximity to the
distal outlet 22 although the exact location may vary. For example,
the dedicated guide wire outlet may be positioned in the lower
surface 34 adjacent the distal outlet or positioned, similar to the
guide wire outlet 36 in FIGS. 3 and 4 (except that the guide wire
would be dedicated or separate from the lead receiving passageway
18). Other locations for the dedicated guide wire outlet are, of
course, possible without departing from the present invention.
Additional views of the dedicated guide wire lumen of the present
invention are provided by FIGS. 15-17 in accordance with an
alternate body design. Turning briefly to FIGS. 15-17, a dedicated
guide wire lumen 172 is defined within the body 162 and receives a
guide wire 190 so as to facilitate identification of a selected
lead placement site. Use of the guide wire will be more
particularly described relative to FIGS. 15-17 below.
[0134] FIG. 5C illustrates the flexible or malleable element 70 in
cross section which will be described in conjunction with FIG. 24.
Turning to FIG. 24, the flexible element 70 includes a proximal end
82 and distal end 84, which is generally coextensive with the
distal end portion 16 of the body 86. The element 70 is disposed
within the body and suitable for manual forming into a desired
shape, such as a shape which corresponds to a surface of the heart
so as facilitate placement of the body 22 adjacent a heart surface.
Both the element and the body are sufficiently flexible so as to
allow the surgeon to change the curvature of the body.
[0135] The flexible element 70 may be in the form of one or more
malleable wires or other like shape-retaining material. In FIG. 24,
the flexible element has been formed with several curvatures along
it length and the distal end portion 16 is curved relative to the
longitudinal axis 13 of the body. The flexible element has the
added characteristic that it is malleable, and retains the desired
shape once it is positioned. Retention of the desired shape is
generally maintained until repositioned by the user. It is also
possible that the shape could be retained by various locking
mechanisms utilized on or within the body.
[0136] FIG. 5D shows the body 5D of a lead placement apparatus
which includes the inflation lumen 74. In a similar manner as the
vacuum lumen 44, the inflation lumen generally extends between
distal and proximal openings. This feature will be described
further in relation to FIGS. 7-8.
[0137] In FIG. 5E, each of the endoscope lumen 76 and the fluid
delivery lumen 78 similarly extend between distal and proximal
openings. The endoscope lumen will be described further in FIGS.
8-10. Relative to the fluid delivery lumen 78, it permits an
introduction of fluid to the heart surface at the selected lead
placement site. The fluid delivery lumen may be connected in fluid
communication with a fluid source at a proximal end of the lead
placement apparatus. A distal opening of the fluid delivery lumen
78 is preferably disposed adjacent the distal outlet.
Temporary Pacing Electrodes
[0138] Turning back to FIGS. 1-4, the body 12 may further include
at least one temporary pacing electrode 72. Although the temporary
pacing electrode is shown in relation to a non-circular body, it is
not intended to limit the temporary pacing electrode as such, and
the temporary pacing electrode may be used in any of the
illustrated body configurations or others not shown.
[0139] In FIGS. 1-4 one temporary pacing electrode 72 is positioned
proximally relative to the distal outlet 22 and another temporary
pacing electrode 72 is positioned distally relative to the distal
outlet at the distal end portion 16 of the body 12. In FIG. 4 the
distal temporary pacing electrode flanks the guide wire outlet 36.
The temporary pacing electrodes are preferably disposed in
proximity to the distal outlet 22 for contact with the surface of
the heart when the body 12 is placed, for example, within the
pericardial space, although other locations may also be
suitable.
[0140] As shown in FIGS. 3 and 4C, a conductor 88 extends from each
temporary pacing electrode 72 to a more proximal portion of the
body 12. By way of example, the conductors 88 may extend to the
proximal end portion 14 of the body for connection to an electrical
pacing signal source, generally indicated at 90 in FIG. 1. Although
the conductors are shown as positioned within the body, it is also
possible that the conductors may extend outside at least a portion
of the body.
[0141] Contact between a heart surface and the temporary pacing
electrode allows temporary pacing of the heart prior to lead
implantation. Temporary pacing allows different surface areas of
the heart to be electrically stimulated, and the effect of such
electrical stimulation can be monitored using appropriate devices
which are apparent to one skilled in the art. After different areas
of the heart are tested for their effect from temporary pacing, the
optimal lead implantation site can be determined. The temporary
pacing electrode may theoretically be adapted to pace the heart by
contact with either one of the epicardial surface or the
pericardium, although it is preferred that the temporary pacing
electrode pace the heart by contact with the epicardial surface and
the use of the temporary pacing electrodes will be described
relative to contact with the epicardial surface.
[0142] FIGS. 5A-5E illustrate the conductors, corresponding to
reference numerals 88A-88E, respectively, extending through the
body, as previously described. The conductors generally extend
parallel to the longitudinal axis of the body and, eventually, are
connected to the pacing signal source. Variations are possible as
to the location of the temporary pacing electrode along the body
and within any of the various body shapes without departing from
this aspect of the present invention. These alternate positions
include but are not limited to the upper surface of the body.
[0143] FIGS. 6A-6C illustrate an alternate embodiment which
includes a body, generally indicated at 92, having an upper surface
91 and a lower surface 93. A monopolar temporary pacing electrode
94 is located at the lower surface 93 of the body 92 (and could be
located in the upper surface if desired). The body 92 also includes
a vacuum lumen 95, a lead receiving passageway 97 with a distal
outlet 99 and a Doppler sensor 80. The vacuum lumen 95 has a distal
opening 96, which is rearwardly positioned relative to the distal
outlet 22. The monopolar temporary pacing electrode 94 has a
conductor 98 which extends along the body to a proximal portion of
the body 92. In FIGS. 6A-6C the monopolar temporary pacing
electrode 94 is located adjacent the distal outlet 22 so as to
allow for pacing of the heart at a location closely adjacent to the
outlet 99 to reflect the electrophysiological consequences of lead
placement at that location prior to actual attachment of the lead.
As discussed above in relation to FIG. 1, the monopolar temporary
pacing electrode is connected via the conductor 98 to a suitable
pacing signal source typically outside the patient's body.
[0144] Turning briefly to FIGS. 23-23B another variation of the
temporary pacing electrode is shown in the form of a removable
conductive probe. A body 100 has a lead receiving passageway 102
extending between a distal end portion 103 and a proximal end
portion 104. At the distal end portion 103, the lead receiving
passageway 102 terminates in a distal outlet 105. The lead
receiving passageway 102 of the body 100 may receive a removable
elongated probe 106 having a proximal end 108 and a distal end 110.
Temporary pacing electrodes 112 may be located on the distal end
110 of the elongated probe 106. Conductors 113 extend through the
probe between the proximal and distal ends 108 and 110 for
connection to a pacing signal source at the proximal end portion
104 of the body 100. The elongated probe 106 with the temporary
pacing electrodes 112 is inserted into the proximal inlet of the
lead receiving passageway 102 and extended along the passageway to
the distal end portion 103 and through the distal outlet 105.
Contact between the conductive electrode(s) and the heart surface
allows pacing of the heart. After the pacing the heart with the
temporary pacing electrodes to establish the desired location for
lead implantation, the probe 106 may be removed from the passageway
102 so as to allow insertion of a lead 114 shown in FIG. 23B
through the passageway 102. The distal end 116 of the lead will be
attached to the selected lead placement site which was determined
by the temporary pacing electrodes to be the suitable lead
placement site.
[0145] Although the temporary pacing electrode has been
particularly described and shown for used in connection with lead
placement, it is contemplated that one or more temporary pacing
electrodes may be used for a variety of other medical procedures
including but limited to other procedures associated with the
heart. For example, the temporary pacing electrode may be used to
repeatedly temporarily pace the heart at a plurality of locations
as necessary so as to map or analyze the conductive pathways of the
heart tissue. The temporary pacing electrode may be disposed on any
of the previously described apparatus of the present invention or
as a separate conductive probe as described above. Other variations
and uses of the temporary pacing electrodes are also possible
without departing from this aspect of the present invention.
Doppler Sensor
[0146] Turning back to FIGS. 6A-6C, the Doppler sensor 80 will now
be described. The Doppler sensor 80 is preferably disposed adjacent
to the distal outlet 99 for the purpose of identifying whether the
lead placement outlet is too close to a coronary artery. A
conductive element 118 having a distal end 117 and a proximal end
119 is in communication with the Doppler sensor 80 at its distal
end 117. The conductive element 118 extends to a more proximal
portion of the body for communication with an operator-readable
output device, which is shown generally at 120 in FIG. 7. In FIG.
6B the Doppler element 80 is positioned in the lower surface 93 of
the body 92 adjacent the distal outlet 99. When the distal end
portion 16 of the body 92 is put into contact with a heart surface,
use of the Doppler sensor allows for detection of a coronary artery
in proximity to the distal outlet 99.
[0147] The structure and function of a Doppler sensor 80 is
apparent to one skilled in the art and is described in U.S. Pat.
No. 4,887,606 to Yock, et al., which is incorporated herein by
reference. Variations in the positioning of the Doppler sensor are
possible although positions adjacent the distal outlet 99 are
preferred in order to more accurately determine the proximity of
the coronary to the distal outlet before attachment of the lead. It
is also possible to configure the Doppler sensor 80 at the end of a
removable elongated probe, similar to the removable probe
previously described relative to FIGS. 23-23B, so as to allow the
Doppler sensor to be removably inserted into the lead receiving
passageway prior to insertion of the lead.
Expandible Member
[0148] Now turning to FIGS. 7-10, a body, generally indicated at
122, is similar in some respects to the body of FIGS. 1-4C with
like parts shown with like number. In other respects, the body 122
of FIGS. 7 and 7A is different in that it includes the inflation
lumen 74, previously described, and an expandible member 124. In
FIGS. 7-10 the expandible member 124 is shown as a balloon although
other forms are also possible, some of which will be described
below.
[0149] As shown in FIGS. 7 and 7A, the expandible member 124 is
disposed in proximity to the distal outlet 22. In FIG. 7 the
balloon 124 is positioned on the upper surface 32 of the body
opposite the distal outlet 22. The balloon extends along the upper
surface 32 of the body from the very end of the distal end portion
16 to a more proximal location along the body. It can be seen that
the body, when it is inserted into a patient adjacent a cardiac
surface and the balloon 124 is expanded by utilizing an inflation
source, the balloon tends to bias the body 122 so that the lower
surface 34 or distal outlet 22 is oriented and held adjacent the
selected heart surface. The inflation lumen 74, as shown in cross
section in FIG. 7A, extends along the body and communicates at its
distal opening with the expandible member 124. A proximal opening
126 of the inflation lumen 74 is connected to an inflation source,
indicated at 128. The inflation source is typically filled with a
fluid, preferably liquid, although a variety of liquids or gases
may be used as will be apparent to one skilled in the art.
[0150] In FIG. 7A the cross-sectional configuration of the body is
shown as non-circular although the invention is not limited to a
non-circular cross-sectional body shape and other shapes are also
possible. The particular body shown in FIGS. 7 and 7A further
includes temporary pacing electrodes connected to corresponding
conductors 88, a Doppler sensor 80, and a vacuum lumen 44 to assist
in positioning the body against the epicardial surface--although
both an inflation device and a vacuum feature may not be required
on the same device. These features are shown by way of example and
other combination of features may be used without departing from
the scope of this aspect of the invention.
[0151] FIGS. 8-9 illustrate another variation of the balloon-type
expandible member with like parts shown with like number. In FIG.
8, a body 130 extending between a distal end portion 16 and a
proximal end portion (not shown) includes an upper surface 32 and a
lower surface 34 along its length. At the distal end portion 16, a
distal outlet 22 is located in the lower surface 34 and a portion
of the lower surface adjacent the distal outlet 22 has a flattened
shape. The expandible member 132 is located along the upper surface
32 and is spaced slightly from the distal end portion 16 of the
body, although it could be directly opposite the outlet 22. FIG. 8
illustrates the unexpanded position of the balloon in solid lines,
and the expanded position of the balloon as dotted lines. In the
unexpanded position the balloon rests substantially against the
upper surface 32 of the body to provide a generally smooth body
surface and a small body profile. In the expanded position, the
balloon is spaced from the upper surface of the body.
[0152] FIG. 9 shows the expanded position of the balloon when the
body 130 has been inserted into the pericardial space S. The body
130 has sufficient length so as to allow insertion of the distal
end portion into the pericardial space. The lower surface 34 of the
body 130 in the vicinity of the distal outlet 22 is oriented
towards the epicardial surface E. Once inserted, the expandible
member 132 is inflated from its non-expanded to expanded position
as fluid flows through the inflation lumen 74 and fills the
balloon. The expanded balloon pushes against the pericardium P,
thus biasing the lower surface 34 of the body 130 into contact with
the epicardial surface E, the distal outlet 22 of the body being
oriented in the desired direction for lead placement.
[0153] In the particular device illustrated in FIG. 8, the body
further includes a dedicated guide wire lumen 68, temporary pacing
electrodes 72, and the endoscope lumen 76, all of which may be used
to facilitate lead placement.
[0154] The functions and construction of the various other
passageways have been previously described. The endoscope lumen 76
extends through the body 130. A distal opening 136 of the endoscope
lumen is located adjacent the distal outlet 22 of the lead
receiving passageway 18. A proximal opening 137 of the endoscope
lumen is disposed on a more proximal location of the body 130. An
endoscope or fiber optic viewing device 138 which has a proximal
and distal ends 140 and 142 is connected to a suitable output
viewing device, such as a video monitor or the like and inserted
into the proximal opening 137 of the endoscope lumen, by way of a
suitable electrical or fiber optic connection. The distal end 142
of the endoscope is advanced to the distal opening 136 and allows
for viewing of the selected lead placement site.
[0155] FIG. 10 illustrates another body 144 which is similar to the
body 130 of FIGS. 8 and 9 with like parts being shown with like
number, except that a balloon-type expandible member 146 extends
completely around the body. In the illustrated example the
expandible member 146 is spaced a small distance from the distal
outlet 22 and is circumferentially disposed on the body. As the
expandible member 146 is inflated to its expanded position, shown
in dotted lines in FIG. 10, it expands outwardly relative to the
body in a radial direction.
[0156] FIGS. 11-12 illustrate a body 148 which is similar to the
one shown in FIG. 8, with like parts being shown with like numbers,
except the body in FIGS. 11-12 has another type of expandible
member, generally indicated at 150, which is comprised of a
plurality of biasing members 152 which are longitudinally and
laterally disposed relative to the body. The biasing members 152
are disposed substantially aligned with the upper surface 32 in an
unexpanded condition. In an expanded position shown in FIG. 1112,
the biasing members 152 form a cage-like structure. As shown in
FIG. 12, the expanded biasing members push against the pericardium
P in order to bias the lower surface 34 in the vicinity of the
distal outlet 22 in contact with the epicardial surface E. The
biasing members are actuated to their expanded position using a
spring, release wire, or other like methods. The biasing members
may be normally biased to their expanded position and held in an
unexpanded position during insertion by a suitable insertion
sleeve, trocar or like device. Alternately, the biasing members may
be moved to the expanded position using a mechanical linkage, pull
wire or the like, which is actuated from a more proximal portion of
the body 150.
[0157] FIG. 13 illustrates an alternate body 154 similar to the one
shown in FIGS. 11-12 except that an expandible member 156 is
disposed circumferentially on the distal end portion of the body
and spaced a small distance from the distal outlet 22. The
expandible member is comprised of biasing members 157 which are
longitudinally and laterally disposed relative to the longitudinal
axis of the body.
[0158] Other types of expandible members are possible in addition
to the expandible members shown in FIGS. 7-13 without departing
from this aspect of the present invention including but not limited
to an elastomeric membrane. Also, more than one expandible member
may be positioned on the body, and if needed, and these may be
positioned at different locations along the body.
Method of Lead Placement
[0159] FIGS. 14-18 illustrate the method of placing a lead on a
heart surface. FIG. 14 shows a patient's chest cavity, including a
rib cage RC, a right lung RL, a left lung LL, a xyphoid XP, a heart
HT, surrounded by a pericardium P, and percutaneous incision 158.
Although the method will be shown and described by employing a
preferred sub-xyphoid approach, this approach is by way of example
and not limitation as other approaches may be utilized to carry out
various aspects of the claimed method with departing from the
present invention. FIG. 14 shows a lead placement apparatus,
generally indicated at 160, which includes a body, generally
indicated at 162.
[0160] In FIGS. 15-17, the body 162 may have a non-circular shape,
such as a convex upper surface 164 and a convex lower surface 166,
and defines a lead receiving passageway 168 terminating in a distal
outlet 170. The body 162 may have a plurality of lumens or
passageways to carry out a variety of functions during the lead
placement procedure. As shown by way of example but not limitation,
these lumen or passageways may include a guide wire lumen 172
terminating at a guide wire outlet 174, temporary pacing electrodes
176 disposed adjacent the distal outlet 170 and connected by way of
conductors 178 through the body to a pacing signal source, an
endoscope lumen 180, and a steering member 182.
[0161] Turning back to FIGS. 14-14D the incision 158 through the
patient's skin is made in the vicinity of the xyphoid XP. Then the
guiding or trocar apparatus 160 is inserted through the
percutaneous incision 158 to the pericardium P. Access to the
pericardial space S as defined between the pericardium P and the
epicardial surface E is made using an appropriate dilator device,
indicated generally at 184, which slices, punctures or otherwise
gains access to the pericardial space through the pericardium.
These devices will be apparent to one skilled in the art and may
include but are not limited to needles, cutting tools, guide wires,
dilators, and other devices. It is noted that the incision 158 is
approximately 3 mm to 5 mm in length and is made in the area of the
xyphoid and the costal cartilage CC. A device such as a needle, or
the like, may then be advanced through the incision 158 toward the
heart. A viewing device may be used to aid the advancement of the
needle. Access can be made into the pericardium employing known
techniques, which by way of example but not limitation these
techniques can include a fluoroscopic contrast injection. A thin
guide wire, indicated generally at 186, such as, for example, a
0.018 inch thickness guide wire is then advanced under fluoroscopic
guidance into the pericardial space. Successively thicker guide
wires can be inserted and removed sequentially into the pericardial
space in order to sufficiently widen the incision for entry of the
body 162. The sizes of these guide wires will vary. Examples of
successively larger guide wires can range approximately between
0.018-0.05 inch and preferred sizes include 0.035 or 0.038 inch. An
introduction sheath, or dilator, indicated generally at 188, may be
introduced over the guide wire into the pericardial space. FIGS.
14A-14D sequentially illustrate the introduction of the needle 184,
the guide wire 186, the dilator 188, and insertion of the lead
placement apparatus 160 through the dilator 188.
[0162] FIGS. 15 and 16 illustrate insertion of the body 162 into
the pericardial space S between the pericardium P and the
epicardial surface E. The body is inserted into the pericardial
space S a distance of approximately between 20 cm and 30 cm. If the
body has a non-circular cross-sectional shape, such shape may
extend along all or a portion of the body which is inserted into
the pericardial space.
[0163] As can be seen in FIG. 16, the distal outlet 170 is defined
in the lower surface 166 of the body 162 so that when the body is
inserted into the pericardial space the distal outlet 170 is
oriented adjacent the epicardial surface E for lead placement.
[0164] In FIG. 15 a guide wire 189 having a distal end 190 and a
proximal end 191 is inserted into the guide wire lumen 172 and
extends forwardly of the guide wire outlet 174. Prior to lead
placement, the guide wire 189 may be used to assist in locating the
desired lead placement site such as for example bisecting tissue to
create a clear path for lead placement. The body 162 is moved
within the pericardial space until the distal outlet 170 is
positioned at a selected lead placement site. Movement of the
distal outlet 170 may be effectuated by the steering wire 182 where
force is applied to the steering member at the proximal end portion
of the body. An endoscope or other viewing device may be inserted
into the endoscope lumen 180 so as to allow viewing of the
epicardial surface as well as the selected lead placement site.
[0165] Prior to lead placement the heart is preferably paced
utilizing at least one temporary pacing electrode 176 positioned
adjacent the distal outlet 170. Pacing of the heart is performed by
placing the electrodes 176 in contact with the surface of the heart
at a selected location so as to determine whether the selection
location is suitable for lead placement. Electrical impulses are
supplied to the heart through the temporary pacing electrodes and
the effect of the such impulses are transmitted to external viewing
devices so as to determine the optimal lead placement site.
[0166] Although the use and function of the temporary pacing
electrode has been particularly described in connection with lead
placement, it is contemplated that the temporary pacing electrode
may be used in connection with a variety of other diagnostic and/or
therapeutic medical procedures such as, for example, for mapping
and analyzing the conductive pathways of the heart. The temporary
pacing electrode may be inserted into the pericardial space either
as part of any of the previously described apparatus or a separate
pacing apparatus. The temporary pacing electrode may be used
repeatedly or sequentially at various locations so as to map and/or
analyze the various conductive pathways of the patient's heart.
[0167] FIG. 16 illustrates a lead 192 having a distal end 194 and a
more proximal end 196. The lead is inserted into the lead receiving
passageway 168. Once the selected lead placement site has been
identified, the distal end 194 of the lead 192 is advanced through
the distal outlet 170 for attachment or engagement to the
epicardial surface E. The lead 192 engages either the epicardial
surface E or the endocardial surface, located beneath the
epicardial surface or both. The distal end 194 of the lead
preferably has an anchor that secures it to the heart surface. The
anchor may take any of several well known forms, such as barb or a
curved and pointed end which may be in the form of a screw or helix
so as to facilitate attachment. Other shapes will be apparent so as
to secure the lead to the heart and different shapes may be
appropriate depending on the degree of lead permanence required.
The steps of lead placement may be repeated so as to engage a
plurality of leads with a surface of the heart.
[0168] FIG. 18 shows the patient's chest after lead placement has
occurred. The lead placement apparatus is withdrawn from the
patient's chest. A portable pacer source 198 may implanted into the
subclavicular space, preferably the left subclavicular space, so as
to provide an electrical pacing signal to the lead 192 by way of a
connection between the proximal end 196 of the lead and the pacer
source 198.
[0169] The method has been shown by way of example but not
limitation using the above steps. It is realized however that other
variations for performing the method of lead implantation are also
possible and may be utilized in place of or in addition to the
steps of the method already described. For example, the method may
be performed utilizing a body having a vacuum lumen describe above
relative to FIGS. 3-4C or FIGS. 6A-6C. A vacuum source provides
suction to hold the distal outlet against the surface of the heart.
In addition, the method of lead placement utilizing the temporary
pacing electrodes is not limited to a body having a non-circular
shape.
[0170] A method of lead placement includes providing a body having
the Doppler sensor 80, as shown and described relative to FIGS.
6A-6C, or a separate Doppler sensor. After the body is introduced
into the pericardial space, the Doppler sensor is placed in contact
with the epicardial surface at a selected location. As discussed
relative to FIGS. 6A-6C, the Doppler sensor is located in the lower
surface of the body although other positions are possible. Once in
contact with the heart surface, the Doppler sensor is activated to
detect whether the sensor or distal outlet 22 is in proximity to a
coronary artery of the heart. The information is transmitted along
the conductive element to the Doppler output device where it is
read by the operator. If a coronary artery is detected, the body is
moved to another lead placement site. Successive detecting is
performed so as to avoid placement of the lead in proximity to a
coronary artery. If no coronary artery is detected unduly close to
the distal outlet, the lead is advanced from the distal outlet and
engaged with one or both of the epicardial and endocardial surfaces
of the heart in a similar manner as shown in FIG. 16. Thereafter,
the lead placement apparatus may be withdrawn. Although the method
may be performed where at least a portion of the body has a
non-circular shape, the method of lead placement which includes the
Doppler sensor is not limited to a body having a non-circular
shape.
[0171] As shown and described in FIGS. 7-13, the expandible member
is deployed from an unexpanded position to an expanded position,
such as by an inflation source or movement of biasing members. The
expandible member is carried by the body and disposed in the
vicinity of the distal outlet so as to hold or bias the distal
outlet against the selected lead placement site. Amongst the
steering members, vacuum lumen and expandible member, any one or a
combination thereof may be utilized so as to orient the distal
outlet against a selected lead placement site.
[0172] The method of lead placement further may include the
introduction of a fluid to the heart surface, in which event the
body has a fluid delivery lumen as described in relation to FIG.
5E.
Lead Removal
[0173] The present invention contemplates a variety of techniques
or body designs that facilitate removal of the lead from the body
after implantation. FIGS. 25-41A are directed to a body
construction and lead arrangement which facilitate removal of the
lead from the lead placement apparatus and, in particular, in which
the lead is removed from the lead placement apparatus in a
direction which is transverse to the longitudinal axis of the body.
Transverse lead removal as described below may be incorporated into
any one or more previously described aspects of the invention.
[0174] FIGS. 25 and 26 illustrate a body 230 having a distal end
portion 232 and a proximal end portion 234. Although the body is
shown having a non-circular shape in the transverse direction along
at least a portion of the body, other shapes may also be
employed.
[0175] In FIG. 25, the body, generally indicated at 230, includes a
longitudinally extending seam or thin wall portion 236, a lead
receiving passageway 238 and passageways 240. The thin wall portion
236 is so called because it is thinner relative to the remaining
portions of the body and it is adjacent to or forms a portion of
the inner surface of the lead receiving passageway. The thin wall
portion 236 extends from a distal end portion 232 of the body to a
more proximal portion of the body, and may extend to the proximal
end portion 234 of the body or any intermediate body position. The
thin wall portion 236 preferably extends at least along the portion
of the body which is inserted into the pericardial space of a
patient. Where a sub-xyphoid approach is employed, the length of
the thin wall portion 236 may range approximately between 10 cm and
40 cm, preferably 20 cm to 30 cm. A lead 240 having a distal end
244 and a more proximal end 246 is shown inserted into the lead
receiving passageway 232 during the lead placement procedure.
[0176] In the embodiment of FIG. 26, the lead 242 is removed from
the body by separating the body along the thin wall portion 236.
The thin wall portion may be thin enough or may even be perforated
along its length so as to facilitate separation. Such separation
may be initiated at the distal end portion 232 of the body or along
a more proximal portion and then separation extends axially in an
"unzipping" manner, from the initial separation site. By way of
example but not limitation, FIG. 26 shows separation of the thin
wall portion extending from the distal end portion 232 and
extending proximally to create a longitudinally disposed opening
along the body. Thereafter, the lead 242 may be removed from the
body in a transverse direction to longitudinal axis 250 of the
body. Although the body is shown-having a plurality of passageways
240 which may incorporate any combination of features previously
described to facilitate lead placement, these passageway are not
intended to limit the present invention.
[0177] FIGS. 27 and 28 illustrate an alternative body, generally
indicated at 252, having a distal end portion 254 and a proximal
end portion 256 and defining a longitudinally disposed channel,
generally indicated at 258, which extends in a proximal direction
from the distal end portion 254. The channel is approximately
C-shaped or U-shaped, and has a bottom wall 257 and side walls 259.
The channel has a top opening 261 to allow for lead removal. The
channel 258 is adapted to receive a lead which is removed through
the top opening 261 in a direction which is transverse to the
longitudinal direction of the body. The channel 258 may extend
along the entire length of the body or any portion of the body.
More specifically, the width of the top opening 261 in the channel
is preferably smaller than the diameter of the lead 242, to
normally retain the lead within the channel. The body is preferably
made of resilient polymeric material so that the side walls 259
flex outwardly to allow the top opening 261 to widen for removal of
the lead.
[0178] FIGS. 29 and 30 illustrate lead removal in accordance with
another aspect of the invention. A body, generally indicated at
260, has a distal end portion 262 and a proximal end portion 264
and defines a channel 266 which is similar to the channel described
in previous FIGS. 27 and 28 having a bottom wall, sides walls and
an top opening except that the body 260 in FIGS. 29 and 30 includes
an elongated C-shaped portion 268 which is received within the
channel 266. The C-shaped portion 268 has a distal end 270 and a
proximal end 272 and, when assembled with the channel, captures the
lead between them.
[0179] Viewed in the transverse direction, as shown in FIG. 30, the
C-shaped portion 268 is located within the channel 266, and has an
outer convex surface 274 that cooperates with the inner concave
surface of the channel 266 and is sized slightly smaller than the
channel 266 so as to be received therein. The assembly of the
C-shaped portion 268 and the channel 266 defines a lead receiving
passageway 278 for insertion of the lead. The body 260 may have a
non-circular shape in the transverse direction although other
shapes are possible. A plurality of passageways 280 also may be
defined within the body and utilized to incorporate the features
previously described. The C-shaped portion 268 may be slidably or
rotatably received within the channel 266. In this embodiment, the
lead may be released in two different ways. First, the C-shaped
portion 268 may be rotated within channel 266 until the gaps or
slots are aligned, allowing the lead to be removed from the body.
Alternatively, the C-shaped portion 268 and channel 266 may be
peeled apart, revealing the lead located therebetween.
[0180] FIGS. 40-41A employ a similar arrangement, and generally
illustrate rotational movement of a longitudinally disposed portion
relative to the remainder of the body. A body, generally indicated
at 282, defines a lead receiving passageway 284 and has a circular
shape in the transverse direction. The body is comprised of inner
and outer longitudinally disposed portions 286 and 287,
respectively, which are concentrically positioned relative to one
another and together define the lead receiving passageway 284 which
receives a lead 288. At least one of the longitudinally disposed
portions is rotated relative to the other. Each inner and outer
portion 286 and 287 has an opening 289 and 291, respectively, which
extends longitudinally along each portion. Although each opening
may vary in size and may vary relative to one another, the size of
each opening is larger than the thickness of the lead so as to
allow for lead removal transverse to the longitudinal axis of the
body when the openings are aligned.
[0181] In FIGS. 40A and 41A, the outer longitudinally disposed
portion 287 extends between a distal end portion 290 and a proximal
end portion 292 and defines a longitudinal axis 294. The inner
longitudinally disposed portion 286 is received within the lead
receiving passageway 284 and extends between a distal end 296 and a
proximal end 298. In FIGS. 40 and 41, at least one of the inner and
outer portions may be curved at an acute angle relative to a
longitudinal axis 294 of the body although other angles of
curvature between 10 degrees and 80 degrees are possible. For
example, one of the inner and outer shaft may be curved and the
other may be straight in a similar manner as described relative to
FIGS. 19-20. The longitudinal position of inner and outer portions
286 and 297 may be fixed relative to one another or capable of
relatively slidable movement.
[0182] FIGS. 40 and 40A illustrate a first position of the body 282
where the openings 289 and 291 are circumferentially non-aligned
relative to one another. The lead 288 is inserted into the
passageway 284 and a distal end 300 of the lead may be advanced
past the distal ends 290 and 296 of both longitudinally-disposed
portions. Removal of the lead may be achieved by rotating at least
one of the inner and outer portions 286 and 287 relative to one
another to a second or opened position, as shown in FIGS. 41 and
41A, in which the openings 289 and 291 are in circumferential
alignment with one another. FIGS. 40A and 41A illustrate rotational
movement of the outer longitudinally disposed portion 287 relative
to the inner longitudinally disposed portion 286 in the direction
indicated by the arrow in FIG. 40A. Removal of the lead is
illustrated by the arrow in FIG. 41.
[0183] Turning back to FIGS. 31-32B, they illustrate another lead
placement apparatus having a body, generally indicated at 302,
which defines a longitudinal axis 304 and a lead receiving
passageway 306, and includes distal and proximal end portions 308
and 310, respectively, and a longitudinally disposed seam indicated
generally at 312. The body 306 is designed to separate along the
longitudinally disposed seam 312 for lead removal in a transverse
direction. The seam 312 is defined by interlocking longitudinal
edges of the body. One of the longitudinal edges includes a
projection 314 and the other longitudinal end includes a recess 316
so that when the body defines a closed position as shown in FIG.
32A the projection 314 is seated within the recess 316.
[0184] Removal of the lead 318 is achieved by separating the seam
at one or both of the distal or proximal end portions 308 and 310.
The body is made of any suitable material or combination of
materials which imparts flexibility characteristics. Examples of
materials include, but are not limited to, polymeric material,
common in medical devices. The material may have shape retention
characteristics such as by thermoforming or the like, so that the
body normally defines a closed position (as seen in FIG. 32A but
without the need for interlocking features), but spreads apart
easily as seen in FIG. 32B. Alternately, a malleable metal strip
may be disposed within the body of FIG. 32A and surrounded by a
non-metal material which maintains a normally closed position.
Force applied to the metal strip may separate the projection 314
from the recess 316. Although the shape of the body 306 is shown as
circular, other shapes, such as the non-circular shapes described
above, are also possible without departing from this aspect of the
present invention.
[0185] In FIGS. 33 and 34, an alternate body, indicated generally
at 320, is shown having distal and proximal end portions 322 and
324, respectively, and including a seam indicated generally at 326,
which is similar to the body in FIGS. 31-32B, except that the seam
is closed by overlapping longitudinal edges 328 and 330,
respectively, along of the body 320. The seam 326 is axially spaced
from a longitudinal axis of the body 332. A lead 338 received
within the passageway 334 may be removed in a transverse direction,
by temporarily spreading the overlapping edges to form a
longitudinal gap through which the lead maybe withdrawn as
indicated in FIG. 33.
[0186] FIGS. 35-37 illustrate a yet further embodiment of the lead
placement apparatus which allows for removal of the lead in a
transverse direction. A body, generally indicated at 340, includes
distal and proximal end portions 342 and 344, respectively, and
defines a lead receiving passageway 346 extending between the
distal and proximal end portions for receiving a lead 348. The body
includes a longitudinally disposed weakened portion 350 which is
bounded between two thin walled portions or other lines of weakness
352. A separate filament or wire is connected to the distal end of
the weakened portion 350, or an extension of the portion 350
extends in a proximal direction terminating at a tab 354 which is
disposed in a more proximal portion of the body. As illustrated in
FIG. 36, removal of the lead 148 from the body 340 may be achieved
by pulling proximally on the tab 354 (or pulling on the wire or
filament), as indicated by the arrow, causing separation along the
thin walled portions 352, thus opening the passageway 346 so as to
allow removal of the lead in a transverse direction.
[0187] In FIGS. 38 and 39 an alternate body, generally indicated at
360, is shown similar to the body shown in FIGS. 35-37, except that
the body 360 includes a longitudinally disposed slide 362 which is
slidably moveable relative to the remaining portion of the body in
order to allow lead removal in a transverse direction. The body 360
includes distal and proximal end portions 364 and 366, respectively
and defines a passageway 368 for receiving a lead. In the
transverse direction shown in FIG. 39 the body may have a circular
or other shape and include a longitudinal opening between two
longitudinally disposed edges 367 extending around the
circumference of the body. The opening is defined along the body
between the distal and proximal end portions 364 and 366. Each
longitudinal edge 367 may include a projection 369 which also
extends along the body and into side slots or recesses 373 of the
slide member 362.
[0188] As shown in FIG. 38, when the slide is slidably moved in a
proximal direction as indicated by the arrow, the opening defined
between the longitudinal edges 369 is unobstructed and permits lead
removal in a direction which is transverse relative to the
body.
Epicardial Lead
[0189] FIGS. 42 and 42A illustrate an epicardial lead, generally
indicated at 380, which is comprised of an elongated outer sheath
382 and an inner member 384. The outer sheath 382 is made of an
insulated material whereas the inner member is conductive. The
sheath 382 includes a distal end portion 386 and a proximal end
portion 388 and defines a longitudinal axis 390 therebetween. The
outer sheath 382 is hollow and is preferably, but not exclusively,
cylindrical in cross-sectional shape. A passageway 392 is defined
by an inner surface of the outer sheath 382 for receiving the inner
member 384.
[0190] As best seen in FIG. 42, the distal end 386 of the sheath
382 is fixed at an acute angle A relative to the longitudinal axis
390. By way of example but not limitation, the angle A is
approximately 20 degrees relative to the longitudinal axis. It is
realized that other acute angles may be utilized, such as between
10 degrees and 80 degrees, although the preferred range of the
angle is between approximately 30 degrees to 60 degrees for
directing a contact member toward the surface or the heart. The
length of the angled portion of the sheath itself may measure
approximately 10 mm to 20 mm.
[0191] As shown in FIG. 42, the inner member 384 has a distal
section 394 and a proximal section 396. As with the sheath 382, the
inner member 384 is elongated relative to the longitudinal axis 390
and generally defines a cylindrical cross-sectional shape. At the
distal section 394, the inner member 384 defines a contact anchor,
which may be in the form of a nonlinear shape, preferably but not
exclusively in the form of a helical or screw-like shape, so as to
facilitate attachment of the inner member 384 to the epicardial
surface of the heart. FIG. 42A shows the inner member 384 as having
a solid cylindrical cross-section, although other configurations
and shapes are also possible without departing from the present
invention. The inner member is preferably made of a flexible or
malleable material and comprises one or more conductive elements or
wires which may be connected to a pacing signal source at the
proximal section 396.
[0192] In FIG. 42A the sheath 382 and the inner member 384 are
capable of movement relative to one another so as to implant the
inner conductive member on the epicardial surface of the heart. For
example, the inner member 384 is moved so as to move the distal
section 394 of the inner member distally of the distal end portion
386 of the outer sheath 382. Any relative movement may be utilized,
such as rotational, translational or a combination thereof. In
addition, the epicardial lead can be configured to allow movement
of the inner member in a direction which is transverse to the
longitudinal axis 390 in accordance with previously described
aspects of the invention.
[0193] When lead implantation is desired, relative movement between
the inner member and the outer sheath causes the distal section 394
of the inner member to be moved through the fixed angle A at the
distal end portion 386. As the distal section 394 passes through
the distal end portion 386, it assumes the angled position relative
to the longitudinal axis 390. Continued relative movement moves the
distal section 394 beyond of the distal end portion 386 for contact
with the heart of a patient and, in particular, the epicardial
surface. The distal section 394 allows for attachment of the inner
member to the epicardial surface of the heart in any conventional
manner, without the need for attachment from an orthogonal
direction as found in prior art leads. For example, the helical
shape of the distal section may be implanted or embedded into the
epicardial surface of the heart by simple rotational movement of
the inner conductive member.
[0194] Turning briefly to FIG. 51-52, FIG. 52 generally illustrates
attachment of the inner member 384 of the epicardial lead 380 to
the epicardial surface E of the heart where the distal section is
disposed at an acute angle I, which ranges approximately between 10
degrees and 80 degrees, preferably between 30 degrees and 60
degrees. By contrast, FIG. 51 shows an epicardial lead, generally
indicated at 398, found within the prior art. The epicardial lead
requires the distal end to be disposed at a right angle R1 so that
the distal end is perpendicular to the epicardial surface and thus
the epicardial lead forms a 90 degree bend relative to radius
indicated at R2.
[0195] FIG. 43 illustrates an epicardial lead 400 similar to the
one shown in FIGS. 42 and 42A, with like parts being shown with
like number, except that an outer sheath 382 of the lead 400 has a
distal end portion 386 which is fixed into a curved shape relative
to the longitudinal axis. The angle, indicated at B, defined by the
distal end portion 386 is preferably in the range approximately
between 10 degrees and 80 degrees, preferably 30 degrees and 60
degrees. The length of the curved portion of the sheath measures
approximately 10 mm to 20 mm.
[0196] FIGS. 44-45A illustrate an epicardial lead, generally at
402, which is comprised of an elongated, hollow outer insulated
sheath 404 and an inner conductive member 406. The sheath 404
includes distal and proximal end portions 408 and 410,
respectively. Likewise, the inner member 406 includes distal and
proximal sections 412 and 414, respectively. The outer sheath 404
defines a passageway 411 for receiving the inner member 406 and a
longitudinal axis 416. As previously described, the outer sheath
404 and the inner member 406 are movable relative to one
another.
[0197] Adjacent the distal end portion 408 of the outer sheath 404,
the sheath includes a collar 418 having a sloped proximal edge 419.
As shown in FIG. 44, the proximal edge slopes downwardly in a
distal direction to define a gap with the remaining portion of the
sheath. Along an upper surface of the sheath, the proximal edge of
the collar is pivotally connected at a hinge 420 to the remaining
portion of the sheath 404.
[0198] As shown in FIGS. 44 and 45, the distal end portion 408 of
the sheath 404 is adapted to move between at least two positions. A
first position is illustrated in FIG. 44. The distal end portion
408 is positioned so that the passageway 411 for receiving the
inner member 406 is in alignment with the longitudinal axis 416.
Along the lower surface of the sheath, the sloped proximal edge 419
is spaced from the remaining portion of the sheath. A second
position is illustrated in FIG. 45 where the distal end portion 408
is disposed at an angle, indicated at C, relative to the
longitudinal axis 416 so that the passageway is disposed at the
angle C relative to the longitudinal axis.
[0199] Movement of the distal end portion is preferably controlled
by a pre-set thermo-formed position of the distal end, or by a
biasing member such as a spring or the like. The distal end portion
is preferably biased such that the normal position of the spring
results in the second position of the distal end portion shown in
FIG. 45. Alternatively, control structures may be carried at the
proximal end portion 410 for controlling the angular position of
the distal end portion. Other control members may be used to vary
the angular orientation of the distal end portion 408 apart from
the angular positions shown and described above without departing
from this aspect of the present invention.
[0200] Numerous variations are also possible so as to permit
attachment of the inner member to the epicardial surface of the
heart at an acute angle. In FIG. 46, an epicardial lead, generally
at 422, includes an outer sheath 424 and an inner member 426. A
distal end portion 428 of the outer sheath carries a sensor 430
such as, for example, a pacing electrode, Doppler sensor, fiber
optic viewing device or endoscope which is connected to viewing
means at a more proximal portion of the epicardial lead 422. The
distal end portion 428 further defines a lumen 432 extending into
the sheath in a proximal direction. The lumen 432 is disposed at an
acute angle relative to the longitudinal axis of the body and
receives the sensor 430 therein. A spring or other biasing member
434 is disposed within the lumen so as to normally bias the sensor
430 in an extended position, illustrated in FIG. 46. Extension and
retraction of the sensor may also be controlled at a more proximal
portion of the epicardial lead.
[0201] In FIG. 46, a distal section 436 of the inner member 426 is
preformed at an angle D relative to the longitudinal axis while the
sheath 426 is aligned relative to a longitudinal axis 437. So when
the distal section 436 extends distally of the sheath 424, the
distal section will form the acute angle D relative to the
longitudinal axis. The distal section is made of any suitable
material which allows it to resume a normally curved position
relative to the longitudinal axis of the lead.
[0202] FIG. 47 illustrates another epicardial lead, generally at
438, having an outer sheath 440 and an inner member 442. A distal
end portion 444 of the sheath 440 is curved at an acute angle,
indicated at E, relative to the longitudinal axis 445 of the lead.
The distal end portion 444 includes a transverse opening 446
relative to the longitudinal axis 445. A distal section 448 of the
inner member 442 is moved through the sheath 440 and extends
through the transverse opening 446. The transverse opening 446 has
a convex inner surface, so that when the distal section 448 of the
inner member 442 is advanced, the distal section engages the convex
inner surface of the opening 446 so as to be disposed at the angle
E relative to the longitudinal axis.
[0203] In FIG. 48 an epicardial lead, generally at 450, which
generally includes an outer sheath 451 and an inner member 453,
includes a steering member 452, such as a pull wire, having a
distal end 454 and a proximal end 456. The distal end 454 of the
steering member is connected in the vicinity of a distal end
portion 458 of the sheath 451. So the distal end portion 458 is
moved upon application of force to the steering member at the
proximal end 456. Tensile compressive or rotational force may be
applied to the steering members so as to move the distal end
portion in a desired direction for lead placement.
[0204] In FIG. 49, an alternate epicardial lead, generally at 60,
utilizes a malleable elongated wire 462 which may be shaped to
retain a desired angular orientation for lead placement. The wire
462 is similar to that previously described in relation to FIG. 24.
Other features may also be utilized to facilitate lead placement in
accordance with previously discussed features.
[0205] FIG. 50 shows an epicardial lead 464 having a distal
section, generally at 466, with an alternate shape. The distal
section 466 has a nonlinear portion 468 as well as a linear portion
470. The linear portion is distally located relative to the
nonlinear portion and is used like a guide wire which may be used
to dissect cardiac tissue and facilitate lead placement. Many other
shapes and orientations are possible are possible without departing
from this aspect of the present invention.
[0206] FIGS. 53-62 illustrate additional variations in the lead
placement apparatus and method of the present invention. In FIGS.
53-56 a lead placement apparatus generally indicated at 468
includes an elongated body generally at 470. The body 470 defines a
longitudinal axis and generally includes a proximal end portion 472
and a distal end portion 474. As shown particularly in FIG. 55, the
body is illustrated having a circular cross sectional shape
although other shapes are also possible. A lead receiving
passageway 476 is defined within the body extending between a
proximal inlet 478 and a distal outlet 480. The passageway 476
generally is shown as a centrally located lumen within the body
although other positions are possible. One or more steering members
482 are disposed within the body and are adapted to deflect the
distal end portion 474 of the body from, for example, a straight
configuration shown in FIG. 54 to a curved configuration shown in
FIG. 56, when force is applied to at least one of the steering
members in the direction indicated by the arrow. The body 470 also
may include at least one temporary pacing electrode 484 and
associated conductive element(s) 486 which connect to a pacing
signal source at a distal end 488, preferably outside of the
patient's body.
[0207] As shown in FIGS. 53-56, the body is suitably flexible so as
to allow deflection of the distal end portion 474 upon application
of force to the steering members. The body also has sufficient
stiffness so as to allow for rotational movement of the body during
the lead placement procedure. The body can be rotated up to 360
degrees relative to its longitudinal axis. It is also possible that
a portion of the body may be rotated relative to the remaining
portion of the body, for example, the portion of the body extending
into the pericardial space may be adapted for rotation up to 360
relative to the handle or proximal end portion 472 of the body.
Because the tip is deflectable in at least one plane and the body
has torsional rigidity that allows it to be rotated, the tip can,
in effect, be deflected up to 360 degrees.
[0208] FIGS. 57-59 illustrate an alternate lead placement apparatus
490 which is similar to the apparatus 468 in FIG. 5356, with like
parts being shown with like number, except that the apparatus of
FIGS. 57-59 includes an annular expandible member 492, preferably a
balloon type expandible member, which is carried by the body 470.
As shown in FIG. 58, an inflation lumen 494 is disposed within the
body 470 and is in fluid communication with an inflation source
generally at the proximal end portion 472 of the body. FIG. 59
illustrates selective expansion of the balloon.
[0209] In FIGS. 60-60A a guiding or trocar device 496 is
illustrated and insertably received within the lead receiving
passageway 476. It is contemplated that the lead receiving
passageway is suitably sized for temporarily receiving devices in
addition to a lead during the lead placement procedure. These
devices are preferably, but not necessarily, removed from the lead
receiving passageway prior to insertion of the lead. A guide wire
498 is insertably received within the trocar device 496 and can be
advanced beyond the distal end portion 474 of the body 470 so as to
help locate the selected lead placement site. As shown in FIG. 61,
a Doppler sensor 500 is generally disposed in proximity to the
distal outlet 480 and is connected through a conductor 501 to an
operator readable output device 503. The Doppler sensor 500 may be
configured as part of a sensing device which is inserted into the
lead receiving passageway 476 and advanced through the body 470 to
the distal outlet 480 for sensing the proximity of the distal
outlet to a coronary artery. Alternatively, the Doppler sensor can
be mounted to the distal end portion 474 of the body in proximity
to the distal outlet 480.
[0210] FIGS. 60-62 also illustrate a method which utilizes the lead
placement apparatus of FIGS. 53-56. In FIG. 60 the trocar 496 and
guide wire 498 are inserted into the lead receiving passageway 476
and through the body 470 so as to facilitate introduction of the
body into the pericardial space. A distal portion of the guide wire
498 may extend beyond the distal end portion 474 of the body 470.
The guide wire 498 may assist in piercing the pericardium or,
alternatively, piercing of the pericardium may be performed
separately by another appropriate instrument, for example, a needle
or other like devices. Thereafter the guide wire and/or the trocar
496 may be inserted into the pericardial space to dilate the
initial incision and widen the incision so as to allow insertion of
the distal end portion 474 of the body 470 into the pericardial
space. The guide wire and trocar are removed from the lead
receiving passageway 476 and, if necessary, additional guide wires,
dilators or other introduction sleeves of larger diameter may be
inserted into the lead receiving passageway 476 so as to suitably
widen the incision for introducing the body 470 into the
pericardial space. Once the distal end portion 474 of the body has
been introduced into the pericardial space, the distal outlet 480
may be oriented in the desired direction for lead placement using
the steering members 482. At least a portion of the body may also
be rotated in 360 degrees. The temporary pacing electrodes 484 may
be placed in contact with successive locations of the epicardial
surface of the heart for pacing of the heart.
[0211] FIG. 61 illustrates insertion of the Doppler sensor 500 into
the lead receiving passageway 476. The Doppler sensor 500 and its
associated sensing device are inserted into the body to detect
whether the selected lead placement site is in proximity to a
coronary artery. If a coronary artery is detected, then the distal
end portion is moved so as to avoid placement of the lead on a
coronary artery. For example, the distal end portion 474 may be
deflected using the steering members or it may be rotated, as
necessary. The Doppler sensor is preferably removed prior to lead
placement.
[0212] In FIG. 62, a lead 504 is inserted into the lead placement
device 468 at the proximal inlet 478 and advanced to the distal
outlet 480. The lead is engaged with the selected lead placement
site. A suitable retention member may be disposed at the distal end
of the lead for attachment to the epicardial or endocardial surface
of the heart. Once lead placement is completed, the lead placement
apparatus may be withdrawn.
[0213] The lead placement apparatus may be utilized to perform the
method in a similar manner as described relative to the lead
placement apparatus of FIGS. 53-56. The expandible member can be
enlarged after the distal end portion of the apparatus has been
inserted into the pericardial space so as to enlarge the existing
working and viewing space at the distal end portion of the
body.
[0214] Accordingly, apparatuses and methods for placing a lead on a
surface of the heart has been provided that meets all the objects
of the present invention. While the invention has been described in
terms of certain preferred embodiments, there is no intent to limit
the invention to the same. Instead it is to be defined by the scope
of the appended claims.
* * * * *