U.S. patent application number 13/153203 was filed with the patent office on 2011-09-29 for transseptal delivery instrument.
This patent application is currently assigned to PACESETTER, INC.. Invention is credited to Phong D. Doan, Dan E. Gutfinger, Paul Hindrichs.
Application Number | 20110238102 13/153203 |
Document ID | / |
Family ID | 44245487 |
Filed Date | 2011-09-29 |
United States Patent
Application |
20110238102 |
Kind Code |
A1 |
Gutfinger; Dan E. ; et
al. |
September 29, 2011 |
TRANSSEPTAL DELIVERY INSTRUMENT
Abstract
Access to the left side of the heart is gained through a heart
wall. A delivery instrument includes a guide that may include or
carry a puncturing instrument that is adapted to be directed toward
the heart wall. In some embodiments a distal portion of the
delivery instrument may be adapted to be co-located with the
coronary sinus. In addition, the guide may be located a known
distance from the portion of the delivery instrument that is
co-located with the coronary sinus. Access to the left side of the
heart may thus be readily gained by positioning the delivery
instrument relative to the coronary sinus.
Inventors: |
Gutfinger; Dan E.; (Irvine,
CA) ; Hindrichs; Paul; (Plymouth, MN) ; Doan;
Phong D.; (Stevenson Ranch, CA) |
Assignee: |
PACESETTER, INC.
Sylmar
CA
|
Family ID: |
44245487 |
Appl. No.: |
13/153203 |
Filed: |
June 3, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11763290 |
Jun 14, 2007 |
7976551 |
|
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13153203 |
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Current U.S.
Class: |
606/184 |
Current CPC
Class: |
A61B 5/0215 20130101;
A61B 90/11 20160201 |
Class at
Publication: |
606/184 |
International
Class: |
A61B 17/32 20060101
A61B017/32 |
Claims
1. An apparatus for accessing a left side of a heart of a patient,
comprising: an elongated structural member, adapted to be routed to
the heart via a superior transvenous approach, comprising a seating
structure on a distal portion of the structural member, the seating
structure adapted to engage tissue adjacent to the ostium of the
coronary sinus of the heart; a guide, coupled with the structural
member, and adapted to carry a piercing instrument and adapted to
reorient at a distal portion to direct the piercing instrument
toward an inter-atrial septum of the heart; and a sliding member,
coupled with the guide, and adapted to be controlled at a proximal
end to reorient the distal portion of the guide.
2. The apparatus of claim 1 wherein the seating structure extends
from the structural member at an angle with respect to a
longitudinal axis of the structural member.
3. The apparatus of claim 1 wherein the seating structure is
adapted to expand from the structural member.
5. The apparatus of claim 1 wherein the seating structure comprises
a plurality of tines.
Description
CROSS REFERENCE TO RELATED APPLICATION
[0001] This application is a division of copending U.S. patent
application Ser. No. 11/763,290 filed Jun. 14, 2007, titled
"Transseptal Delivery Instrument the content of which is
incorporated herein by reference in its entirety.
TECHNICAL FIELD
[0002] This application relates generally to implantable cardiac
devices and, in some embodiments, to a transseptal delivery
apparatus for and a transseptal method of accessing a left side of
a heart.
BACKGROUND
[0003] When a person's heart does not function normally due to, for
example, a genetic or acquired condition, various treatments may be
prescribed to correct or compensate for the condition. For example,
pharmaceutical therapy may be prescribed for a patient or a
pacemaker or similar device may be implanted in the patient to
improve the function of the patient's heart.
[0004] In conjunction with such therapy it may be desirable to
detect conditions in or apply therapy to one or more chambers of
the heart. For example, an implanted device may sense electrical
activity in a chamber and, based on the sensed conditions, apply an
electrical stimulus to a chamber. Similarly, an implanted device
may measure cardiac pressure in a given chamber in an attempt to
determine how the heart is functioning. Then, based on the pressure
reading, the patient's therapy may be modified to compensate for
any undesirable conditions. For example, if cardiac pressure is
measured over time, the operation of an implanted cardiac device
such as a cardioverter defibrillator may be adjusted, as necessary,
according to conditions diagnosed as a result of the pressure
measurements.
[0005] Traditionally, access to one or more chambers of the heart
has been gained via the venous system. That is, a cardiac lead is
inserted into a vein and then routed through the venous system to a
chamber on the right side of the heart.
[0006] In some cases, however, it is desirable to sense conditions
or provide treatment to a chamber on the left side of the heart.
For example, left atrial pressure has been identified as a
potential indicator for left ventricular failure. Access to the
left side of the heart may be obtained from the right side of the
heart by routing a lead through a septal wall that separates a
right chamber from a left chamber. Accordingly, there is a need for
an effective mechanism that provides access to the left side of the
heart via a transseptal technique.
SUMMARY
[0007] A summary of various aspects and/or embodiments of an
apparatus constructed or a method practiced according to the
invention follows. For convenience, an embodiment of an apparatus
constructed or a method practiced according to the invention may be
referred to herein simply as an "embodiment."
[0008] The invention relates in some aspects to an apparatus or
method for accessing the left side of a heart. For example, a
delivery instrument may be routed through the venous system to the
right side of the heart. Using the delivery instrument, a puncture
may be made in a wall of the heart to gain access to the left side.
An implantable device may then be inserted into or through the wall
to, for example, acquire information from or provide therapy to the
left side.
[0009] In some embodiments access to the left atrium is gained
through the inter-atrial septum. Here, a portion of the delivery
instrument may be adapted to be co-located with the coronary sinus.
For example, in some embodiments the delivery instrument may
include a protruding member that is adapted to rest on and/or
around tissue adjacent the ostium of the coronary sinus. In some
embodiments the delivery instrument may include one or more markers
that may be sensed by an imaging apparatus. The imaging apparatus
may thus be used to identify the position of the markers relative
to the ostium of the coronary sinus.
[0010] The delivery instrument includes a guide that is used to
gain access to the left atrium. For example, the guide may include
or carry a puncturing instrument that is adapted to be directed
toward the inter-atrial septum. To this end, the guide is located a
known distance in a proximal direction from the portion of the
delivery instrument that is co-located with the coronary sinus. By
proper setting of this distance, the puncture may be readily made
at a desired location in the inter-atrial septum.
[0011] In some embodiments the delivery instrument may be used to
access a portion of the heart at or near the fossa ovalis. For
example, the delivery instrument may be adapted (e.g., sized) so
that once a distal portion of the delivery instrument engages the
coronary sinus, the puncturing instrument may be readily (e.g.
automatically) directed toward a wall of the heart at or near the
fossa ovalis.
[0012] Through the use of such a delivery instrument, a physician
may take advantage of his or her ability to access to the coronary
sinus to readily gain access to the left atrium. Specifically, many
physicians who regularly implant cardiac devices have extensive
experience implanting leads via the coronary sinus. For example, to
sense or stimulate the left side of the heart a physician may
implant a lead through the coronary sinus. A physician may use
these same skills to co-locate the delivery instrument located with
the coronary sinus. At this point, the delivery instrument may
automatically direct the puncturing instrument through the
inter-atrial septum at a desired location, thereby potentially
eliminating steps that the physician would otherwise use to
determine where to puncture the inter-atrial septum.
[0013] Similarly, a physician may be able to use simpler and/or
more cost effective imaging techniques since the physician may have
a high level of confidence that the delivery instrument will pierce
the inter-atrial septum at the desired location. For example, an
implant procedure may be performed using, for example, only
fluoroscopic guidance. Accordingly other techniques such as
echocardiography may not be needed.
[0014] In some embodiments the delivery instrument also may be used
to implant leads. For example, the delivery instrument may include
one or more lumens for carrying (e.g., routing) a lead to an
implant site (e.g., where the puncturing instrument created a
hole). Thus, once a distal portion of the delivery instrument
engages the coronary sinus and the puncturing instrument has
created a hole, a distal portion of the lead may be routed through
the delivery instrument and into the hole (e.g., in a septal wall,
at or near the fossa ovalis, etc.).
[0015] In some embodiments the delivery instrument also may be used
to implant leads via the coronary sinus. For example, the delivery
instrument may include one or more lumens for carrying (e.g.,
routing) one or more leads into the coronary sinus to an implant
site that provides sensing and/or stimulation for the left atrium
and/or the left ventricle.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] These and other features, aspects and advantages of the
invention will be more fully understood when considered with
respect to the following detailed description, appended claims and
accompanying drawings, wherein:
[0017] FIG. 1 is a simplified diagram of an embodiment of a
delivery instrument positioned in a heart;
[0018] FIG. 2 is a simplified diagram of an embodiment of a
delivery instrument;
[0019] FIG. 3 is a simplified diagram of an embodiment of a
delivery instrument in an engaged orientation;
[0020] FIG. 4 is a simplified diagram of an embodiment of the
delivery instrument of FIG. 3 in a retracted orientation;
[0021] FIG. 5 is a flow chart of an embodiment of operations that
may be performed to implant a lead or a device in a patient;
[0022] FIG. 6 is a simplified diagram of an embodiment of the
delivery instrument of FIG. 4 carried within a delivery sheath;
[0023] FIG. 7 is a simplified diagram of an embodiment of a
guidewire-like piercing instrument routed through a delivery
instrument;
[0024] FIG. 8 is a simplified diagram of an embodiment of a distal
locking mechanism of a guidewire-like piercing instrument;
[0025] FIG. 9 is a simplified diagram of an embodiment of a
guidewire-like piercing instrument implanted in a heart;
[0026] FIG. 10 is a simplified diagram of an embodiment of a sheath
and dilator routed over a guidewire;
[0027] FIG. 11 is a simplified diagram of an embodiment of a lead
implanted in a heart;
[0028] FIG. 12 is a simplified diagram of an embodiment of a guide
of a delivery instrument that directs a piercing instrument toward
a septal wall of a heart;
[0029] FIG. 13 is a simplified diagram of an embodiment of the
guide of FIG. 12 in a retracted orientation;
[0030] FIG. 14 is a simplified diagram of an embodiment of a
guidewire;
[0031] FIG. 15, including FIGS. 15A, 15B and 15C, is a simplified
diagram of an embodiment of a delivery instrument;
[0032] FIG. 16 is a simplified diagram illustrating an embodiment
of a delivery instrument having a curved shape to facilitate secure
placement of the delivery instrument;
[0033] FIG. 17 is a simplified diagram of an embodiment of a
delivery instrument ; and
[0034] FIG. 18 is a simplified diagram of an embodiment of a
delivery instrument.
[0035] In accordance with common practice the various features
illustrated in the drawings may not be drawn to scale. Accordingly,
the dimensions of the various features may be arbitrarily expanded
or reduced for clarity. In addition, some of the drawings may be
simplified for clarity. Thus, the drawings may not depict all of
the components of a given apparatus or method. Finally, like
reference numerals may be used to denote like features throughout
the specification and figures.
DETAILED DESCRIPTION
[0036] The invention is described below, with reference to detailed
illustrative embodiments. It will be apparent that the invention
may be embodied in a wide variety of forms, some of which may
appear to be quite different from those of the disclosed
embodiments. Consequently, the specific structural and/or
functional details disclosed herein are merely representative and
do not limit the scope of the invention. For example, based on the
teachings herein one skilled in the art should appreciate that the
various structural and/or functional details disclosed herein may
be incorporated in an embodiment independently of any other
structural and/or functional details. Thus, an apparatus may be
implemented and/or a method practiced using any number of the
structural and/or functional details set forth in any disclosed
embodiment(s). Also, an apparatus may be implemented and/or a
method practiced using other structural and/or functional details
in addition to or other than the structural and/or functional
details set forth in any disclosed embodiment(s). Accordingly,
references to "an" or "one" embodiment in this discussion are not
necessarily to the same embodiment, and such references mean at
least one embodiment.
[0037] FIG. 1 illustrates an embodiment of an apparatus 100
(referred to herein as a delivery instrument) that may be used to
deliver one or more implantable leads or other devices to a heart H
of a patient. In particular, the delivery instrument 100 may be
used to implant a lead or other device through a wall of the heart
H. For convenience, FIG. 1 only shows a distal portion of the
delivery instrument 100 after it has been positioned in the heart
H. It is to be understood that the instrument comprises a thin
elongated structure that is adapted to be routed through the venous
system and that a proximal end of the delivery instrument 100 may
include various lumens and/or connectors to properly interface with
and/or control the components at the distal portion. Also, the
heart H is shown in a partially cutout view (as represented by a
dashed line 134) to more clearly show the location of some of the
components of the delivery instrument 100.
[0038] The delivery instrument 100 may be inserted into the heart H
via a superior transvenous approach. For example, a distal portion
of the delivery instrument 100 may initially be inserted into a
vein near a subcutaneous implant site for an implantable cardiac
device in a pectoral region of the patient (not shown in FIG. 1).
The distal portion of the delivery instrument may then be routed
through the venous system and into the heart via the superior vena
cava 104.
[0039] The delivery instrument 100 includes an elongated, flexible
component 106 (hereafter referred to as a "guide") that is used to
gain access to the left side of the heart H. For example, the guide
106 may be adapted to provide an orientation where a distal end 108
of the guide 106 is directed to a heart wall such as the
inter-atrial septum 110 as shown in FIG. 1. For convenience a heart
wall may be referred to herein simply as a septum. It should be
appreciated, however, that the structure and functions taught
herein may be used to access regions other than a septum.
[0040] The guide 106 is adapted to carry (e.g., hold and/or direct
the course of) an instrument 112 that creates a hole in the septum.
For convenience, such an instrument may be referred to herein as a
piercing instrument. It should be appreciated, however, that such
an instrument may use techniques other than piercing to create a
hole in a septum. For example, a piercing instrument may be adapted
to drill or cut or use any other suitable technique to create a
hole in or provide other similar access through the septum.
[0041] Once the guide 106 is in an engaged positioned (e.g., the
distal end 108 is directed toward a particular location on the
septum 110 as shown in FIG. 1), the piercing instrument 112 may be
routed through the guide 106 such that a distal end 114 of the
piercing instrument 112 is directed toward that same location. The
piercing instrument 112 may then be pushed, turned, etc., to create
a hole in the septum 110.
[0042] In some embodiments the piercing instrument 112 may function
as a guidewire that facilitates delivering other components to the
hole. For example, a guidewire-like instrument 112 may include a
sharp distal end 114 and be adapted to temporarily maintain its
position on the distal side of the septum (e.g., in the left
atrium). Here, the instrument 112 may include an expandable locking
mechanism on its distal end. Once the locking mechanism is
positioned in the left atrium, the locking mechanism may be
expanded to a size that is larger than the diameter of the hole
(see, e.g., locking mechanism 130 in FIG. 2). This, in turn,
prevents the distal end of the instrument 112 from being pulled out
of the left atrium. Once the guide 106 is removed from the
guidewire, one or more other components (e.g., a sheath) may then
be routed over the instrument 112 to the hole to enable a lead or
other device to be implanted in the septum. Thus, this is one way
the delivery instrument 100 may be adapted to carry a lead to an
implant site. To remove the instrument 112, the locking mechanism
is reconfigured to its original orientation thereby permitting the
distal portion of the instrument 112 to pass back through the hole.
These and other related operations are discussed in more detail
below.
[0043] Alternatively, a separate guidewire may be used with the
delivery instrument 100. In some embodiments, after the piercing
instrument 112 creates the hole, a guidewire (not shown) may be
routed through a lumen in the piercing instrument 112 then through
the hole. The piercing instrument 112 is then removed, leaving the
guidewire in place. The guidewire may have at its distal end a
pig-tail configuration or some other suitable structure designed to
prevent inadvertent dislodgement from the left atrium.
Alternatively, in some embodiments the piercing instrument 112 is
removed from the guide 106 so that a guidewire may be routed
through the guide 106 and through the hole in the septum.
[0044] In some embodiments the delivery instrument 100 may be
adapted to carry a lead to the implant site. For example, the guide
106 also may be adapted to carry an implantable lead.
[0045] The delivery instrument 100 also includes an elongated
structural member (hereafter referred to as "component 116") that
facilitates positioning the guide 108. A distal portion of the
component 116 is adapted to engage (e.g., rest upon or be embedded
within) tissue associated with (e.g., adjacent to or within) the
coronary sinus. For convenience, such an engagement may simply be
referred to herein as engaging the coronary sinus. For example, in
some embodiments the component 116 may include one or more
structural members 118 (e.g., tines or other suitable structure)
that extend from the component 116 and are adapted to engage tissue
associated with the coronary sinus. For example, upon implant a
member 118 may be positioned to rest upon or otherwise engage
tissue 132 adjacent an orifice (the ostium 120) of the coronary
sinus. Through the use of members 118, the distal portion of the
component 116 may be maintained at a known position. For
convenience, a structural member adapted to be seated against or
otherwise interact with tissue may be referred to herein as a
seating structure. In some embodiments a distal portion 122 of the
component 116 may be adapted to enter the coronary sinus. This also
may serve to maintain the distal portion of the component 116 at a
known position.
[0046] Through the use of a positioning component such as component
116, the delivery instrument 100 may be adapted to readily create a
hole at a desired location in the septum 100. For example, when the
guide 106 is in an engaged position the distal end 108 may be
adapted to be a specified distance from a distal portion of the
positioning component 116 that is engaged in tissue associated with
(e.g., adjacent to or within) the coronary sinus.
[0047] FIG. 2 illustrates an example of such a distance
relationship (for clarity, the heart H is omitted in FIG. 2). Here,
the distal end 108 of the guide 106 is located a distance "d" from
a portion (e.g., an end portion) of the tines 118 that may rest
upon tissue adjacent the ostium of the coronary sinus. In some
cases, the distance "d" may be measured from a hinge point of the
tines 118 in the event the tines 118 will be pressed flat against
the tissue. In some patients it may be desirable to define the
puncture location at approximately 25 mm proximal to the level of
the ostium of the coronary sinus in a plane perpendicular to the
inter-atrial septum.
[0048] Advantageously, the delivery instrument may be adapted to
provide ready (e.g., automatic) access to an area of the heart at
or near the fossa ovalis. Here, the spatial relationship (e.g.,
distance and angle) between the coronary sinus and the fossa ovalis
or the membranous part of the septum may be relatively consistent
from patient to patient; particularly among those patients with a
sick, and consequently enlarged, heart. For example, for many
patients the distance "d" may be on the order of 2-3 cm. Thus, a
delivery instrument may be provided for use with multiple patients
with a single (or a few) predefined distance and angle relationship
between these areas.
[0049] By adapting (e.g., sizing and spacing components of) the
delivery instrument such that the distance "d" is properly
specified, the piercing instrument 112 may be readily directed to a
location in the inter-atrial septum at which it is desirable to
create a hole. Consequently, a physician may readily gain access to
the left atrium through the use of a familiar coronary sinus access
procedure. That is, the physician positions the delivery instrument
100 at the coronary sinus in the same way the physician would
position a sheath or other component during a typical coronary
sinus lead implant procedure. Once the delivery instrument 100 is
positioned in this manner, the guide 106 may automatically be in
position to direct the piercing instrument 112 through the
inter-atrial septum at the desired location. For example, referring
again to FIG. 1 the delivery instrument may thus be adapted to
create a hole in the fossa ovalis 126, a membranous portion of the
septum 128, a muscular portion of the septum or some other
location.
[0050] FIG. 2 also illustrates that the component 116 may include a
distal portion 124 that is inserted into the coronary sinus. As
discussed above, the portion 124 may help to securely position the
delivery instrument 100 in the heart. In some embodiments the
seating structure 118 may be positioned to ensure that only a
specified length of the distal portion 124 of the delivery
instrument 100 is placed into the coronary sinus.
[0051] In some embodiments the component 116 may comprise a
catheter adapted to carry one or more leads or other components to
the venous branches of the coronary sinus. For example, such a
catheter may include a lumen for implanting a lead that is adapted
(e.g., includes electrodes and coil at appropriate locations) to
sense signals in and/or provide stimulation (e.g., pacing or
shocking) signals to the left atrium and/or the left ventricle.
Thus, the same delivery instrument 100 may be used for implanting
leads or other components in both the coronary sinus and the left
atrium. Consequently, additional flexibility may be provided for
sensing and/or stimulating the left atrium, left ventricle other
parts of the heart.
[0052] A delivery instrument as taught herein may thus provide an
easy to obtain anatomical reference point for accessing the left
side of the heart. In addition, the seating structure or other
positioning techniques may provide an effective leverage point for
the delivery instrument. Such a leverage point may prove useful
when applying pressure at a proximal end of the delivery instrument
to reorient the guide and/or create the hole in the septum.
[0053] Referring now to FIG. 3, various examples of components of a
delivery instrument 300 will be discussed. For convenience only the
distal portion of the delivery instrument 300 is shown.
Accordingly, it should be understood that several of the components
(e.g., components 302, 308 and 312) extend to a proximal end of the
delivery instrument.
[0054] This embodiment of a delivery instrument includes a main
catheter 302 (e.g., an elongated structural member that may be
somewhat similar to the component 116) and a guide 304. In some
embodiments the main catheter 302 is adapted to carry at least one
lead (not shown) adapted for implant in the coronary sinus as
discussed above. The example of FIG. 3 also shows that in some
embodiments the seating structure (e.g., tines 306) may be
connected to or extend from a distal end of the main catheter
302.
[0055] The guide 304 in this example includes a sealed track 308
that is adapted to carry (e.g., within a lumen) one or more of a
piercing instrument, a guidewire, and a lead (not shown in FIG. 3).
For example, a piercing instrument/guidewire may be inserted into a
proximal end of the sealed track 308 and routed through the sealed
track 308 until the distal end of the piercing instrument/guidewire
exits the distal end of the sealed track 308. In some embodiments
the sealed track may take the form of a catheter. Accordingly, for
convenience, the sealed track may be referred to as a "guide
catheter."
[0056] The guide 304 is adapted such that the guide catheter 308
may be reoriented between the positions shown in FIGS. 3 and 4.
Thus, when the delivery instrument 300 is routed through the venous
system distal portions 310 and 318 of the guide catheter 308 may be
oriented to lie substantially parallel to a longitudinal axis of
the main catheter 302 as shown in FIG. 4. Then, once the distal
portion of the delivery instrument 300 has been co-located with the
coronary sinus, the distal portion 310 of the guide catheter 308
may be oriented at an angle to the longitudinal axis of the main
catheter 302 as shown in FIG. 3. The selected angle may depend on
the requirements of a given case. In some cases the distal portion
310 may be reoriented to be substantially perpendicular to the
longitudinal axis of the main catheter 302. Other cases may use a
smaller or larger angle.
[0057] FIG. 3 illustrates one example of how the guide 304 may be
coupled with the main catheter 302. It should be appreciated that a
variety of other fixation mechanisms may be used to couple or
otherwise join these components or any similar components discussed
herein. Alternatively, in some embodiments, the guide 304 and main
catheter 302 may comprise an integrated component.
[0058] In FIG. 3 the guide catheter 308 is coupled to an attachment
member 312 of the guide 304. The member 312 is adapted to
facilitate reorientation of the guide catheter 308 and coupling of
the guide 304 with the main catheter 302. Here, the member 312 may
include one or more fixtures 314 that fasten the member 312 to the
main catheter 302.
[0059] In some embodiments the guide 304 is releaseably coupled to
the main catheter 302. For example, the fixtures 314 may slide
within a track 316 of the main catheter 302 or be mounted in some
other manner that facilitates separation of the guide 304 from the
main catheter 302. In this way, the guide 302 may be released from
the main catheter 302 in the event this is desirable at some point
in time during the implant procedure.
[0060] Similarly, in some embodiments the member 312 may be
repositionable on the main catheter 302. In this way, the distance
"d" between the distal portion 310 and the seating structure 306
may be adjusted as necessary. Various mechanisms may be used to
provide such repositioning. For example, a mechanism may provide
several fixed positions or a range of positions. In addition, such
a mechanism may employ fasteners or any other suitable coupling
mechanism.
[0061] The member 312 also includes several components that
facilitate reorienting the guide catheter 308. A coupler 324
slideably carries the guide catheter 308. That is, the guide
catheter 308 is free to slide within the coupler 324 in either a
distal or a proximal direction.
[0062] The member 312 and/or the guide catheter 308 also may
include a mechanism to restrain sliding of a distal portion of the
guide catheter 308 relative to the member 312. In this way, the
guide catheter 308 is forced to reorient when the guide catheter
308 is pushed in a distal direction. For example, a portion 318 of
the guide catheter 308 may bend outwardly when a physician pushes
the proximal end of the guide catheter 308 in a distal direction.
Here, the portion 318 may be predisposed to bend in a given
direction (e.g., outward). In an alternative embodiment discussed
below, reorientation is achieved by sliding a member (somewhat
similar to member 312) in a proximal direction with the guide
catheter 308 (or similar structure) held steady.
[0063] In the example of FIG. 3, a coupler 320 serves to carry and
hold the distal portion 310. For example, the coupler 320 prevents
the distal portion of the guide catheter from moving in a distal
direction further beyond the coupler 320. In the example of FIG. 3,
the guide catheter 308 may include a stop 322 or the member 312 and
the guide catheter 308 may include a fixation mechanism 322 to
prevent the guide catheter 308 from moving further past the coupler
320.
[0064] The coupler 320 may be further adapted to facilitate
reorientation of the distal portion 310. For example, as shown in
FIGS. 3 and 4, the coupler 320 may reorient (e.g., bend) as the
distal portion 310 reorients.
[0065] FIG. 4 illustrates that the delivery instrument 300 may
incorporate one or more imaging markers 326 and 328 (e.g., made of
radio-opaque material). These markers may be used in conjunction
with imaging equipment to verify the location of and/or aid in the
positioning of the delivery instrument 300. Such imaging equipment
may utilize, for example, x-ray, fluoroscopy or any other suitable
imaging technique.
[0066] In some embodiments, one or more markers may be employed on
a distal portion of the main catheter 302 to verify that a distal
portion of the delivery instrument is co-located with (e.g.,
resting on or positioned next to) tissue associated with the
coronary sinus. For example, in some embodiments one or more
markers 326 may be mounted on or incorporated into one or more of
the tines 306. In some embodiments the position of the delivery
instrument is determined by lining up the ostium of the coronary
sinus with one or more markers (not shown) mounted on or
incorporated into a distal portion of the main catheter 302. Such a
configuration may be used instead of or in addition to other
positioning techniques (e.g., as discussed herein).
[0067] In some embodiments, one or more markers may be employed on
a distal portion of the delivery instrument 300 to determine the
rotational orientation (i.e., about the longitudinal axis) of the
delivery instrument 300. For example, markers 328 of various shapes
and locations (or one marker) may be mounted on or incorporated
into the main catheter 302 and/or the guide 304. The relative
positions of the markers 328 as detected by imaging equipment may
provide an indication as to the rotational orientation of the
delivery instrument 300. In this way, the attending physician may
determine whether the delivery instrument 300 needs to be rotated
to ensure that the distal portion 310 of the guide catheter 308 is
directed toward the septum or other desired location. For example,
when a patient is lying on his or her back, the distal portion 310
may be directed generally downward (toward the posterior of the
heart) to pierce the fossa ovalis.
[0068] With the above description in mind, additional details of a
transseptal implant procedure will now be discussed in conjunction
with FIGS. 5-11. FIG. 5 is a flowchart illustrating selected
implant operations. FIGS. 6-11 illustrate examples of how the
delivery instrument and other components may be routed into and/or
positioned in the heart.
[0069] Referring now to FIG. 5, as represented by block 502 the
delivery instrument is initially routed to the heart via a superior
transvenous technique. Thus, a distal portion of the delivery
instrument may initially be inserted into a vein above the heart
and routed through the venous system into the heart
[0070] As illustrated in FIG. 6, a delivery instrument 600 may be
placed in a sheath 602 prior to implant to facilitate routing the
delivery instrument 600 through the venous system. For convenience,
the sheath 602 is depicted in phantom to more easily show the
components of the delivery instrument 600 within the sheath 602.
Here, it may be seen that the seating structure 604 (e.g., tines)
may be adapted to orient to a position that is substantially
parallel to a longitudinal axis of the delivery instrument 600.
Alternatively, in other embodiments the seating structure may be
retractable (e.g., using a stylet) whereby the seating structure is
drawn into the distal portion of the delivery instrument during
delivery (not shown).
[0071] Once the distal portion of the delivery instrument 600
reaches the interior of the heart, the seating structure 604 may be
allowed to reorient to an extended orientation. For example, in
embodiments that use the sheath 602, the sheath 602 may be
withdrawn from the delivery instrument 600. The seating structure
604 may then automatically (e.g., by spring or memory action)
expand from the delivery instrument (e.g., as shown in FIG. 4). In
embodiments that use a retractable seating structure, the seating
structure may be extended out of the delivery instrument at this
time.
[0072] As represented by block 504, the delivery instrument is
co-located with the coronary sinus. As discussed above, in some
embodiments this may involve positioning a distal portion (e.g., a
seating structure such as tines) of the delivery instrument against
tissue associated with the coronary sinus as shown in FIG. 1. In
some embodiments this may involve using imaging (e.g., of the
coronary sinus and markers on the delivery instrument) to verify
whether a distal portion of the delivery instrument is at a desired
position relative to the coronary sinus.
[0073] At block 506, the guide on the delivery instrument is
reoriented such that the distal end of the guide is directed toward
the septum (e.g., as shown in FIGS. 1 and 3). As discussed herein,
this may be accomplished in some embodiments by pushing or pulling
on one or more sytlets that extend from a proximal end of the
delivery instrument to the guide and/or associated components at
the distal end of the delivery instrument.
[0074] As represented by block 508, the guide is then used to
pierce the septum. For example, as shown in FIG. 7 a piercing
instrument 702 is routed through a guide 704 (shown in a simplified
form) placed in the right atrium ("RA") and forced through the
septum S to create a hole 706 through the septum S to the left
atrium ("LA").
[0075] Next, at block 510, a guidewire (e.g., a guidewire-like
piercing instrument or other suitable component) 802 is routed
through the hole 706 in the septum S (FIG. 8). A distal portion of
the guidewire 802 will thus be positioned in the left atrium as
illustrated in FIG. 8.
[0076] A locking mechanism 804 may then be deployed to temporarily
prevent the distal portion of the guidewire 802 from being pulled
out of the left atrium (block 512). Various mechanisms may be used
for this purpose. For example, in some embodiments a locking
mechanism may comprise a braided wire portion of a guidewire
wherein the braided portion expands in a radial manner into a set
of overlapping loops (e.g., to form a small umbrella-like
structure) upon deployment of the locking mechanism. Here, the
locking mechanism may be deployed by sliding a stylet in the
guidewire. In other embodiments the locking mechanism may take the
form of a pig-tail-like curl or some other suitable form. Several
examples of locking structures are described in U.S. Patent
Application Publication No. 2006/0196137, filed Feb. 23, 2006, the
disclosure of which is hereby incorporated by reference herein.
[0077] Once the locking mechanism 804 has been deployed, the guide
may be removed from the guidewire (e.g., as depicted in FIG. 9). In
some embodiments this may involve withdrawing the entire delivery
instrument from the heart leaving only the guidewire in place. In
other embodiments only certain components may be withdrawn at this
point. For example, in embodiments where the delivery instrument
includes a catheter for implanting a coronary sinus lead, it may be
desirable to leave the coronary sinus catheter in the heart at this
point of the procedure. Consequently, as discussed herein, the
delivery instrument may be adapted such that one or more components
are releaseably attached to another component. For example, in some
embodiments the guide may be released from the coronary sinus
catheter. In this case, only the guide may be withdrawn from the
heart. In some embodiments a guide catheter may be releaseably
attached to the guide. Thus, in this case, only the guide catheter
may be withdrawn.
[0078] As represented by block 514 and illustrated in FIG. 10, a
dilator 1002 and a sheath 1004 are routed over the guidewire 802.
The dilator 1002 is forced into the hole 706 to widen the hole 706
so that the sheath 1004 may be routed through the hole 706. After
the sheath 1004 is inserted into the hole 706, the dilator 1002 and
the guidewire 802 may be withdrawn.
[0079] As represented by block 516 and illustrated in FIG. 11, a
lead 1102 may then be routed through the sheath to implant the
distal end of the lead 1102 into or through the hole in the septum.
Here, one or more attachment mechanisms (e.g., tines) 1104 may be
employed to secure the distal end of the lead (or an associated
device) to the septum (block 518).
[0080] The lead 1102 may include one or more devices for sensing
conditions in or providing therapy to the left atrium. For example,
a pressure sensor 1106 may be located at the distal end of the lead
1002. The pressure sensor 1106 may thus be positioned on the left
side of the heart (or be coupled to a pressure wave carrying
channel exposed to the left side of the heart) to obtain pressure
readings from the left side of the heart. It should be appreciated
that the lead may incorporate other devices (e.g., electrodes) for
sensing or providing treatment.
[0081] Referring now to FIGS. 12 and 13, various details of an
embodiment of a guide 1200 will be discussed. The guide 1200
includes a catheter 1202 adapted to carry a guide catheter 1204 and
a flexible, elongated member 1206 (e.g., a wire, a stylet, etc.).
The guide catheter 1204 is adapted to slideably carry a piercing
instrument and/or a guidewire 1208 as discussed herein.
[0082] As represented by the arrows 1216, one or both of the guide
catheter 1204 and the elongated member 1206 may slide within the
catheter 1202. In this way, the guide 1200 may be reoriented
between a retracted position (FIG. 13) and an engaged position
(FIG. 12). The arrow 1216 in FIG. 13 illustrates an embodiment
where a sliding movement of the elongated member 1206 in a distal
direction (to the right in FIG. 13) causes the guide catheter 1204
to straighten.
[0083] The guide catheter 1204 is coupled with the elongated member
1206 via a flexible coupling mechanism 1210 and associated fixtures
1212 and 1214. Here, the operation of the coupling mechanism 1210
facilitates reorientation of the guide catheter 1204. Specifically,
as the guide catheter 1204 is moved to the right (or the elongated
member 1206 is moved to the left), the coupling mechanism bends to
facilitate reorientation of the guide catheter 1204 to an
orientation with a sharp out-of-plane turn as illustrated in FIG.
12.
[0084] The coupling mechanism 1210 may take various forms. In the
example of FIGS. 12 and 13, the coupling mechanism 1210 comprises a
pair of flexible wires that are fixed to the guide catheter 1204
and the elongated member 1206 by suitable fixtures 1214 and 1212,
respectively. It should be appreciated based on the teachings
herein that other suitable coupling mechanisms may be incorporated
into a delivery instrument.
[0085] Referring now to FIG. 14, in some embodiments a guidewire
(e.g., the guidewire-like piercing instrument) 1400 may include one
or more lumens. For example, in some embodiments the guidewire 1400
may have an internal lumen 1402 that is used to record pressure
waveforms. Here, the lumen 1402 may transfer pressure waves to a
pressure analysis component 1406. Alternatively, the lumen 1402 may
include a pressure sensor 1404 that sends pressure reading signals
to a pressure analysis component 1406. In some embodiments the
guidewire 1400 may have an internal lumen 1408 with a port 1410
that is used to aspirate blood that is sent to a blood analysis
component 1412. The data collected by either of these techniques
may be beneficial for confirming entry into the desired cardiac
chamber. For convenience the guidewire 1400 is depicted in FIG. 14
with multiple lumens. In practice, however, a guidewire may
incorporate a different number of lumens (e.g., typically one). The
piercing instrument 1400 also may include electrodes 1414A and
1414B that are coupled, via conductors 1418A and 1418B, to an
electrical signal analysis component 1416 that measures electrical
activity. In this case, the encountered electrical measurements may
be used to further verify and pinpoint the location where the
puncture across the septum will be performed.
[0086] In some embodiments a piercing instrument/guidewire may be
used to partially puncture the right side of the septum wherein the
locking mechanism is activated prior to performing the puncture.
When a partial puncture is performed into the septum, the piercing
instrument may be used to evaluate electrical pacing and sensing
performance at the puncture site. If the sensed electrical
performance proves to be adequate, a full puncture may then be
performed. If the sensed electrical performance is inadequate, then
the puncture site may be modified by adjusting the distance "d" or
a decision may be made to abort the procedure.
[0087] A variety of structures may be employed to securely hold an
implantable lead in place and to direct a piercing instrument to a
desired location in the heart. Additional examples of such
structures will now be discussed in conjunction with FIGS. 15, 16
and 17.
[0088] FIG. 15 illustrates an embodiment of a delivery instrument
1500 that includes a catheter 1504 (e.g., a delivery tube) and a
guide structure 1506 (a portion of which is depicted as being
shaded) that are adapted to slide longitudinally with respect to
one another and within a main catheter 1502. All of the components
associated with the catheter 1504 and the guide structure 1506
shown in FIG. 15 are adapted to (e.g., are sufficiently flexible)
to enable these components to be collapsed as necessary to slide
within the main catheter 1502. FIG. 15 illustrates a condition
where the components have been pushed out of a distal end of the
catheter 1502.
[0089] When the catheter 1504 is pushed in a distal direction
relative to the guide structure 1506, engagement of a distal
portion of the catheter 1504 with a portion 1508 of the guide
structure 1506 causes the catheter 1504 to deflect as shown in FIG.
15C. Consequently, the delivery instrument 1500 may facilitate
delivery of a piercing instrument 1510 through the catheter 1504 at
an angle that enables direct access to a heart wall (e.g., the
septum between the left and right atria).
[0090] The guide structure 1506 includes a structural member 1512
(e.g. a tube-like component) at its distal end that may be adapted
to partially enter the coronary sinus and also includes a flexible
structural member 1514 (e.g., a wire-like component) that may be
adapted to engage tissue adjacent the ostium of the coronary sinus.
Through the use of the components 1512 and 1514, the distal end of
the delivery instrument 1500 may be seated within and against the
coronary sinus to secure the delivery instrument 1500 in place and
add support for deflecting the catheter 1504 and forcing the
piercing instrument 1510 through the septal wall.
[0091] Several of the components of the guide structure 1506 will
now be treated in more detail. A proximal link member 1516 extends
through the main catheter 1502 to the proximal end of the main
catheter 1502 to enable the guide structure 1506 to be
independently slid with respect to the main catheter 1502 and the
catheter 1504. A linking member 1518 attaches the structural member
1512 with the main (shaded) portion of the guide structure
1506.
[0092] The main portion of the guide structure 1506 may be
U-shaped, for example, open at the top as viewed in FIG. 15. The
structure 1508 may comprise a tube-like structure within which the
distal end of the catheter 1504 may enter. The portion of the
structure 1506 between upright elements 1508 and 1520 may comprise
four strips 1522A-D that form an angular array around the catheter
1504. The annular array is depicted, in part, in FIG. 15B which
illustrates the catheter 1504 and the guide structure 1506 as seen
from view A-A in FIG. 15A. In this view, the upright elements 1508
and 1520 that support the strips 1522A-D are not present. FIG. 15B
illustrates that the shape of the guide structure 1506 restricts
the bending of the catheter 1504 (as shown in FIG. 15C) to an
upward direction, as viewed from the perspective of FIG. 15.
[0093] A flexible structural member 1524 (e.g., a wire-like
structure) serves to further hold the catheter 1504 relative to the
guide structure 1506. The structure 1524 essentially comprises a
flexible loop having an apex at a distal end of the catheter 1504
and an apex at a proximal wall of the structure 1512. As shown in
FIG. 15B, the arms of the structure 1524 extend outward from the
catheter 1504 and between either the strips 1522A and B or the
strips 1522C and D. From FIGS. 15A and C it may be seen that the
structure 1524 allows the catheter 1504 to slide relative to the
guide structure 1506, yet prevents the distal portion of the
catheter 1504 from completely exiting the guide structure 1506.
[0094] The structure 1514 extends from the structure 1524 to form a
partial loop that extends over the guide structure 1506. In
examples of FIGS. 15 A and 15C, the loop is depicted as extending
over the member 1518. Thus, it should be appreciated that the loop
formed by the structure 1514 may be manipulated to reorient from a
relatively flat orientation (longitudinal with the axis of the main
catheter 1502) upon delivery through a vein to a relatively
perpendicular orientation upon implant. In the latter case, the
structure 1514 may, for example, provide a seating structure for
engaging tissue such as the tissue surrounding the ostium of the
coronary sinus as discussed herein.
[0095] FIG. 16 illustrates, in a simplified manner, an embodiment
of a distal portion of a body 1600 of a delivery instrument
implanted in patient's heart. As discussed above, a distal end 1602
of the instrument body 1600 may engage the ostium O of the coronary
sinus.
[0096] The body 1600 is formed with a resilient curved portion
1604. The instrument body 1600 is constructed of a sufficiently
flexible material such that the curved portion 1604 may be
straightened as necessary (e.g., using a guide wire) for delivery
through the vasculature system.
[0097] Once the curved portion 1604 is located at a desired
location (e.g., in the superior vena cava SVC and the right atrium
RA), the curved portion 1604 may be allowed to return to its
predisposed curved shape. In this way, once the instrument body
1600 is oriented in an appropriate manner, the curved portion 1604
may serve to hold a portion 1606 of the instrument body 1600
against an area of a septal wall S where it is desired to puncture
the septal wall S. As illustrated in FIG. 16, the curved shape of
the portion 1604 also may cause another portion 1608 of the
instrument body 1600 to lie against another wall W of the heart
(e.g., an inner wall of the superior vena cava SVC). Consequently,
the shape of the portion 1604, in conjunction with the engagement
of the coronary sinus, may serve to more securely hold the portion
1606 of the instrument body 1600 at the desired location during
deployment of a guide, during septal piercing or during other
similar operations.
[0098] FIG. 17 illustrates another embodiment of a delivery
instrument comprising a catheter 1700. A structure 1702 is
selectively extendable from the catheter 1700. The structure 1702
carries a resiliently expandable structure 1704. When the
structures 1702 and 1704 are inside the catheter 1700 the structure
1704 is collapsed within the inner wall of the catheter 1700. When
the structures 1702 and 1704 are extended from the catheter 1700 as
shown in FIG. 17, the structure 1704 resiliently expands to a
relatively large shape (e.g., a two-dimensional shape) as shown.
This shape of the structure 1704 may be held relatively flat
against an adjacent tissue surface (e.g. the septum), for example,
by the action of the engagement of a portion of the catheter 1700
with a wall of the heart as shown in FIG. 16. In addition, in some
implementations the delivery instrument 1700 may be incorporated
into a main structure (e.g., component 116) that engages the
coronary sinus as discussed above.
[0099] After the structure 1704 has been deployed, the structure
1706 may be pushed distally relative to the other components. The
structure 1702 includes a component 1708 (e.g., a flexible
structure) that prevents the distal end of the structure 1706 from
passing beyond a desired point within the structure 1704. The
engagement of the distal portion of the structure 1706 causes its
distal portion to bend as shown in FIG. 17. This aims the distal
end of the structure 1706 toward a desired tissue location and at a
desired angle relative to the surface of that tissue. A tissue
engaging (e.g., penetrating) structure 1710 may then be extended
distally from the structure 1706 as shown in FIG. 17 to engage
(e.g., penetrate) that tissue at the desired location and at the
desired angle.
[0100] FIG. 18 illustrates another embodiment of a delivery
instrument comprising a catheter 1800. The catheter 1800 may
include components 1702, 1706, 1708 and 1710 as in FIG. 17.
However, in this embodiment the structure 1702 carries a
resiliently expandable structure 1802 (e.g., attached to a portion
1804 of the structure 1802). When the structures 1702 and 1802 are
inside the catheter 1800 the structure 1802 is collapsed within the
inner wall of the catheter 1800. When the structures 1702 and 1802
are extended from the catheter 1800 as shown in FIG. 18, the
structure 1802 resiliently expands to a relatively large shape
(e.g., a two-dimensional shape) as shown. This shape of the
structure 1802 may be adapted to engage the coronary sinus as
discussed herein. For example, the structure 1802 may fit inside or
may fit around the ostium of the coronary sinus. It should be
appreciated that the structure 1802 may be implemented in other
configurations (e.g., a different shape than depicted in FIG. 18)
to engage the coronary sinus.
[0101] From the above it is should be appreciated that a delivery
instrument constructed in accordance with the teachings herein may
prove beneficial for certain transseptal implant procedures. Such a
delivery instrument may be used, for example, to implant permanent
transvenous leads as part of a pre-pectoral pacemaker,
defibrillator, hemodynamic sensor system or other system into the
left atrium or the left ventricle where a transseptal puncture
across the inter-atrial septum is being performed from a superior
transvenous approach via, for example, the jugular, subclavian or
axillary veins.
[0102] Since most physicians that implant bi-ventricular pacing
systems can reliably access the coronary sinus, having a delivery
instrument for performing transseptal punctures across the
inter-atrial septum that utilizes a coronary sinus catheter or
similar structure as a platform provides a natural extension of the
current techniques for implanting leads. Moreover, a coronary sinus
catheter-based delivery apparatus as taught herein may be suitable
for performing not only the traditional lead implantation into the
coronary sinus venous system, but also a transseptal lead
implantation in which a lead will be delivered across a septum into
the left atrium or the left ventricle.
[0103] It should be appreciated from the above that the various
structures and functions described herein may be incorporated into
a variety of apparatuses (e.g., a catheter) and implemented in a
variety of ways other those specifically described herein. Various
structures may be used to implement the guide, the piercing
instrument/guidewire, the seating structure, the catheters, the
elongated member, the locking mechanisms, the markers and other
components. For example, a guidewire as used herein may comprise a
conventional guidewire or any elongated, flexible member that is
suitable for guiding a component or device to an implant site or
other site in a heart. In addition, various mechanisms may be used
to guide a piercing instrument/guidewire to the septum. The
components described herein may be constructed of various
materials. For example, many of the components may be constructed
of conventional implantable lead materials including polymers such
as silicone or polyurethane or some other suitable material. Also,
the components described herein may be oriented in a various ways.
For example, a guide, a seating structure or a marker may be
located at various positions or on various components at the distal
end of the delivery instrument. The components described herein may
be coupled (e.g., connected) in various ways using fasteners,
adhesives, bonding techniques or other suitable mechanisms. The
techniques described herein may be applicable to other walls of the
heart and/or may be used to access other chambers of the heart.
[0104] Moreover, the recited order of the blocks in the processes
disclosed herein is simply an example of a suitable approach. Thus,
operations associated with such blocks may be rearranged while
remaining within the scope of the present disclosure. Similarly,
the accompanying method claims present operations in a sample
order, and are not necessarily limited to the specific order
presented.
[0105] While certain exemplary embodiments have been described
above in detail and shown in the accompanying drawings, it is to be
understood that such embodiments are merely illustrative of and not
restrictive of the broad invention. In particular, it should be
recognized that the teachings of the invention apply to a wide
variety of apparatuses and methods. It will thus be recognized that
various modifications may be made to the illustrated and other
embodiments described above, without departing from the broad
inventive scope thereof. In view of the above it will be understood
that the invention is not limited to the particular embodiments or
arrangements disclosed, but is rather intended to cover any
changes, adaptations or modifications which are within the scope
and spirit of the invention as defined by the appended claims.
* * * * *