U.S. patent application number 16/908196 was filed with the patent office on 2020-10-08 for snaring systems and methods.
The applicant listed for this patent is SPECTRANETICS LLC. Invention is credited to Dave ATWELL, Wade BOWE, George BURTON, Kevin D. TAYLOR.
Application Number | 20200315643 16/908196 |
Document ID | / |
Family ID | 1000004915173 |
Filed Date | 2020-10-08 |
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United States Patent
Application |
20200315643 |
Kind Code |
A1 |
TAYLOR; Kevin D. ; et
al. |
October 8, 2020 |
SNARING SYSTEMS AND METHODS
Abstract
Snaring systems and methods involve engaging objects such as
pacemaker pacing leads within a patient. Physicians can use snaring
systems having loops, tags, and roller mechanisms to remove a
pacing leads from a patient. For example, snaring systems can he
inserted through a jugular access site, engaged with a pacemaker
pacing lead, and withdrawn through the jugular access site so as to
remove a portion of the pacing lead. Lead extraction techniques can
be employed to further dislodge the pacing lead from the
patient.
Inventors: |
TAYLOR; Kevin D.;
(SNOQUALMIE, WA) ; BURTON; George; (COLORADO
SPRINGS, CO) ; ATWELL; Dave; (COLORADO SPRINGS,
CO) ; BOWE; Wade; (COLORADO SPRINGS, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
SPECTRANETICS LLC |
Colorado Springs |
CO |
US |
|
|
Family ID: |
1000004915173 |
Appl. No.: |
16/908196 |
Filed: |
June 22, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15893378 |
Feb 9, 2018 |
10687836 |
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16908196 |
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14978731 |
Dec 22, 2015 |
9918729 |
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15893378 |
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12878648 |
Sep 9, 2010 |
9220523 |
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14978731 |
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61242225 |
Sep 14, 2009 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61N 2001/0578 20130101;
A61B 17/3468 20130101; A61B 17/221 20130101; A61B 2017/2217
20130101 |
International
Class: |
A61B 17/221 20060101
A61B017/221; A61B 17/34 20060101 A61B017/34 |
Claims
1. A snaring system, comprising: a tube comprising a distal end, a
wall, and a first lumen formed within the wall, wherein the first
lumen comprises a first cross-sectional shape; and a snare wire
comprising a distal section configured to extend distal of the
distal end of the tube and a proximal section configured to extend
within the first lumen of the tube, wherein the distal section is
configured to engage an object within a patient body, wherein the
distal section comprises the first cross-sectional shape such that
the distal section is configured to be fitted into the first lumen,
and wherein the proximal section comprises a second cross-sectional
shape different than the first cross-sectional shape.
2. The snaring system of claim 1, wherein the tube comprises a
central longitudinal axis, wherein the first lumen is laterally
offset from the central longitudinal axis.
3. The snaring system of claim 1, wherein the tube further
comprises a second lumen.
4. The snaring system of claim 3, wherein the first lumen and the
second lumen are parallel.
5. The snaring system of claim 3, wherein a cross-sectional area of
the second lumen is larger than the cross-sectional area than the
first lumen.
6. The snaring system of claim 3, wherein the tube comprises a
central longitudinal axis, wherein the second lumen is aligned with
the central longitudinal axis.
7. The snaring system of claim 3, wherein the distal section
comprises a first portion and a second portion proximal of the
first portion, wherein the first portion comprises an open loop,
and wherein the second portion comprises the first cross-sectional
shape.
8. The snaring system of claim 7, wherein the snare wire is
configured to translate relative to the tube, and wherein the open
loop is configured to extend into the second lumen when the snare
wire is translated proximally.
9. The snaring system of claim 8, wherein the first cross-sectional
shape of the distal section is configured to be received within the
first lumen when the snare wire is translated proximally.
10. The snaring system of claim 1, wherein the second
cross-sectional shape is configured to allow rotation of the snare
wire relative to the tube.
11. The snaring system of claim 1, wherein the object comprises a
lead such that the distal section is configured to engage the lead
for removal of the lead from the patient body.
12. The snaring system of claim 1, wherein the proximal section of
the snare wire further comprises a handle configured to rotate
and/or translate the snare wire relative to the tube.
13. The snaring system of claim 1, wherein the first lumen is open
at the distal end of the tube.
Description
CROSS-REFERENCES TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. patent
application Ser. No. 15/893,378, filed Feb. 9, 2018, now U.S. Pat.
No. 10,687,836, which is a continuation of U.S. patent application
Ser. No. 14/978,731, filed Dec. 22, 2015, now U.S. Pat. No.
9,918,729, which is a continuation of U.S. patent application Ser.
No. 12/878,648, filed Sep. 9, 2010, now U.S. Pat. No. 9,220,523,
which is a nonprovisional of and claims the benefit of priority to
U.S. Provisional Patent Application No. 61/242,225, filed Sep. 14,
2009. The contents of each of the above applications are
incorporated herein by reference for all purposes.
BACKGROUND OF THE INVENTION
[0002] Embodiments of the present application relate generally to
systems and methods for separating or removing an object from a
patient, and more specifically, to techniques for grasping pacing
leads within a patient.
[0003] A pacemaker can be used to improve heart function in a
patient. For example, a pacemaker can transmit electrical signals
to the patient's heart, so as to assist the heart to beat in a
desired heart rhythm. A pacing system typically includes a
pacemaker, a pacing lead, and a controller or processer. A pacing
lead often has a wire that transmits electrical impulses to cardiac
tissue. Optionally, a pacing lead may transmit information
regarding cardiac activity to the pacemaker or processor.
[0004] In certain situations, it may be desirable or necessary to
remove a pacing lead from a patient. For example, a patient may
develop an infection in tissue which is contacting the pacing lead
or pacemaker. It may also be advantageous to remove the lead or
lead fragment if the lead breaks or otherwise poses a risk of
damage, discomfort, or obstruction or interference, if the lead
interferes with the operation of another implanted device, or if
the patient's vasculature or tissue which is located at or near the
lead becomes obliterated or occluded.
[0005] In some cases, a lead may develop or present a free end,
which can occur when a lead breaks, is pulled out of a header, or
is otherwise abandoned during a surgical intervention. If a lead
has a free end, it is typically located in the brachiocephalic
vein. To remove a lead having a free end, it may be desirable for
the physician or operator to navigate the free end of the lead
toward an incision site.
[0006] Several lead grasping and removal techniques have been
proposed. However, some approaches may not be well suited for
easily accessing, grasping, or manipulating the free end of a lead.
For example, some pig tail catheters may have a limited holding
capability, and the lead may slip out of the catheter before it is
freed from the patient's anatomy. In certain instances, pig tail
catheters can tend to straighten out when pulled by the operator,
thus disengaging the lead from the pig tail. Some snares grasp the
lead with inappropriate levels of force. Hence, there continues to
be a need for improved systems and methods that can simply and
effectively grasp and remove a pacing lead or other object from a
patient in a reliable manner.
[0007] Although some currently proposed treatments may provide real
benefits to patients in need thereof, still further advances would
be desirable. Embodiments of the present invention provide or
intravascular hook or snaring solutions that address the problems
which may be associated with the techniques described above, and
hence provide answers to at least some of these outstanding
needs.
BRIEF SUMMARY OF THE INVENTION
[0008] Grasping snares and method for grasping a pacing lead and
removing it from the body are disclosed herein. For example, an
operator may advance a snaring system through a jugular access site
in a patient, providing a relatively non-tortuous pathway to the
superior vena cava where the snaring system can be engaged with a
pacing lead. Using the snaring system, it is possible to maneuver
the pacing lead, which optionally may involve pulling the lead so
as to disengage a proximal portion or a distal portion of the lead
from an attachment site within the patient. Once a distal or
proximal portion of the pacing lead is disengaged, the physician
can maneuver the free end toward the access site, by loosely
engaging the snaring system with the pacing lead. In some cases,
this may involve the use of a snaring system having one or more
roller bearings or sleeves. The snaring system can be translated
along a length of the pacing lead, and can be used to maneuver or
pull a free end of the pacing lead, without transmitting an
excessive amount of pulling force or stress on the opposing secured
end of the pacing lead.
[0009] Advantageously, such grasping snares may be operated with
significant pulling forces, while maintaining an engagement with a
pacing lead. Exemplary snaring systems include a snare wire with a
hooked distal end that is slidable within the wall or lumen of an
outer sheath or jacket. Such arrangements permit the distal end of
the snare wire to be moved distally away from the outer jacket in
order to snare the pacing lead. Once grasped, the pacing lead can
be pulled back into the inner lumen of the outer jacket so that it
can be withdrawn from the body. Embodiments of the present
invention also encompass deflection tendons or bending wires that
can be incorporated into the outer jacket to bend or deflect the
distal tip of the outer jacket. Embodiments may also include snares
having a closed hook at their distal end. A distal end or snare
hook may have one or more rotatable bearings. In use, a snare can
be inserted into the jugular vein of a patient. The snare can be
used to grasp or engage the pacing lead and pull one end out
through the jugular vein access site. Once the lead end is
extending outside the body, typical lead extraction techniques can
be employed. In some cases, grasping snare wires can be extended or
advanced through a wall of a catheter body.
[0010] Relatedly, embodiments of the present invention encompass
systems and methods for snaring or grasping a lead which is
disposed within an anatomical location of the patient, such as the
jugular vein, the superior vena cava, the right atrium, the right
ventricle, the brachiocephalic vein, or the like. Advantageously,
the techniques disclosed herein allow a surgeon or operator to
effectively grasp, push, pull, twist, rotate, or otherwise maneuver
or manipulate an object, such as a pacing lead, within the patient.
What is more, snaring systems disclosed herein can withstand high
pulling forces without releasing a pacing lead, and can effectively
snare a lead in a midsection or central portion, without being
threaded over the end of the pacing lead. Exemplary snaring systems
allow a pacing lead to slide through a distal hook of a snare wire,
without imparting high forces to the pacing lead or adhered
vasculature. Features such as a hook tag end and a bent or shaped
snare wire allow an operator to effectively steer or navigate the
snare system to the pacing lead for capture. Moreover, snaring
systems disclosed herein are easily releasable from the pacing
lead. In some cases, snaring systems can include a hook or snare
that can hook and retain a pacing lead, and pull a portion of the
pacing lead downward toward the femoral vein or upward toward the
jugular vein and out of the access site. Systems can also allow the
pacing lead to move through a snare wire or catch mechanism as the
lead is being pulled or during the snaring process. Exemplary
embodiments can also release a hook or snare if the procedure is
not successful or is interrupted.
[0011] In one aspect, embodiments of the present invention
encompass snaring systems and methods for engaging an object within
a patient's body. An exemplary snaring system includes an elongate
element having a proximal end and a distal end. The distal end can
include a loop. The system also includes an outer sheath having a
central lumen. The central lumen can be configured to receive at
least a portion of the loop of the distal end of the elongate
element. In some cases, a system may also include a rotatable
bearing in operative association with the loop of the distal end of
the elongate element. The distal end of the elongate element can
include a tag, and the central lumen of the outer sheath can be
configured to receive the tag. In some embodiments, the outer
sheath includes a second lumen extending through a side wall of the
sheath, and the second lumen is configured to receive at least a
portion of the elongate element. In some cases, the elongate
element includes a flattened portion, a square cross section
portion, or a rectangular cross section portion. Optionally, the
system may include a deflection mechanism coupled with the outer
sheath.
[0012] In another aspect, embodiments of the present invention
encompass systems and methods for engaging a pacing lead disposed
within a patient. An exemplary method includes inserting a snaring
system through a jugular or femoral access site of a patient,
engaging a pacing lead with the snaring system, sliding the snaring
system along a length of the pacing lead so as to move a portion of
the pacing lead toward the jugular or femoral access site of the
patient, and withdrawing the snaring system from the jugular or
femoral access site so as to remove at least a portion of the
pacing lead from the patient. In some cases, the step of engaging
the pacing lead can include engaging the pacing lead with a roller
mechanism of the snaring system. In some cases, the step of
engaging the pacing lead can include engaging the pacing lead with
a capture mechanism of the snaring system. Optionally, the capture
mechanism of the snaring system can include an elongate element
having a loop. In some cases, the step of engaging the pacing lead
can include sliding the elongate element along a side wall lumen of
a catheter of the snaring system.
[0013] In a further aspect, embodiments of the present invention
encompass systems and methods for engaging an object disposed
within a patient. An exemplary method may include inserting a
snaring system through an access site of a patient. The snaring
system can include an elongate element having a distal loop and a
rotatable roller mechanism disposed along the distal loop of the
elongate element. The method may also include engaging the object
with rotatable roller mechanism of the snaring system, and
withdrawing the snaring system toward the access site so as to move
at least a portion of the object toward the access site. In some
cases, the elongate element may include a tag end that is disposed
distal to the rotatable roller mechanism. The rotatable roller
mechanism may include a bearing having a tubular shape. Optionally,
the rotatable roller mechanism may include a bearing having a
spherical shape. In some cases, the rotatable roller mechanism
includes a first cylindrical bearing defining a first central
longitudinal axis and a second cylindrical bearing defining a
second central longitudinal axis. The first central longitudinal
axis can be angularly offset from the second central longitudinal
axis. In some instances, the first central longitudinal axis is
angularly offset from the second central longitudinal axis by about
90 degrees.
[0014] In still another aspect, embodiments of the present
invention encompass a snaring system for engaging an object within
a patient's body, which includes an elongate element having a
proximal end and a distal end. The distal end of the elongate
element can include a loop and a tag. The snaring system may also
include a rotatable bearing in operative association with the loop
of the distal end of the elongate element. In some cases, the
rotatable bearing is disposed on a first section of the loop, and
the loop has a second section distal to the first section and a
third section proximal to the first section, such that the second
section and the third section are in substantial parallel
alignment. In some cases, the first section is in substantial
perpendicular alignment with each of the second section and the
third sections.
[0015] For a fuller understanding of the nature and advantages of
the present invention, reference should be had to the ensuing
detailed description taken in conjunction with the accompanying
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIGS. 1A to IF illustrates aspects of object grasping or
removal systems and methods according to embodiments of the present
invention.
[0017] FIG. 2 illustrates aspects of an object removal system or
grasping snare according to embodiments of the present
invention.
[0018] FIGS. 3A to 3D illustrate aspects of an object removal
system or grasping snare according to embodiments of the present
invention.
[0019] FIGS. 4A and 4B illustrate aspects of a grasping snare
system according to embodiments of the present invention.
[0020] FIGS. 5A and 5B illustrate aspects of a grasping snare
system according to embodiments of the present invention.
[0021] FIG. 6 illustrates aspects of an object removal or snaring
system according to embodiments of the present invention.
[0022] FIGS. 7A and 7B illustrates aspects of pacing lead snaring
or removal systems and methods according to embodiments of the
present invention.
[0023] FIG. 8 depicts aspects of a snaring system according to
embodiments of the present invention.
[0024] FIG. 9 depicts aspects of a snaring system according to
embodiments of the present invention.
[0025] FIG. 10 depicts aspects of a snaring system according to
embodiments of the present invention.
[0026] FIGS. 11 to 11C depict aspects of a snaring system according
to embodiments of the present invention.
[0027] FIGS. 12A to 12C depict aspects of a snaring system
according to embodiments of the present invention.
[0028] FIGS. 13A and 13B depict aspects of a snaring system
according to embodiments of the present invention.
[0029] FIGS. 14A and 14B depict aspects of a snaring system
according to embodiments of the present invention.
[0030] FIGS. 15 to 15C depict aspects of a snaring system according
to embodiments of the present invention.
DETAILED DESCRIPTION OF THE INVENTION
[0031] In certain surgical situations, a patient may present with a
pacing lead that is no longer disposed within the pocket, but
instead is freely floating in the brachiocephalic vein, the
superior vena cava, the right atrium, or the like. Embodiments of
the present invention provide techniques for grasping a free end of
the pacing lead and maneuvering or pulling it toward the jugular
vein. Exemplary approaches provide removal or snare systems that
can hook, grasp, push, pull, and twist a pacing lead. Such advances
allow an operator may degrees of freedom when removing a lead
having a free end.
[0032] According to embodiments of the present invention,
techniques may include pulling the free end of the lead down from
the femoral vein using a femoral vein approach. Once the lead is
located within the right atrium or inferior vena cava, the
physician can use a snare device inserted through the jugular vein
to grasp or engage the lead and pull it toward an opening or
incision in the jugular vein. The free end of the lead can be
pulled back up through the jugular vein, via the inferior vena
cava, right atrium, and superior vena cava. In some cases, this
technique can involve using a first snare to hook the lead and pull
the lead down through the inferior vena cava and into the femoral
vein. The technique can also involve using a second snare to grasp
or engage the end of the lead from a jugular access site, and pull
the free end up through the jugular access site. Optionally, a
laser sheath or other removal device can then be used over the lead
to free or dislodge the distal end of the lead for removal.
[0033] Turning now to the drawings, FIGS. 1A to 1F illustrates
aspects of an object grasping or removal system 100 according to
embodiments of the present invention. FIG. 1A shows a pacing lead
10 disposed within a patient's body, such that a free end 12 of the
lead is floating freely within the brachiocephalic vein. As
depicted in FIG. 1B, an object grasping or removal system 100 can
be advanced within the jugular vein, and then used to snare, grasp,
hook, or otherwise engage the pacing lead. In some cases, grasping
or removal system 100 is used to grasp or engage pacing lead 10 at
or near a central portion 14 of the pacing lead. Optionally,
grasping or removal system 100 can be used to grasp or engage a
portion of pacing lead 10 which is disposed at or near the right
atrium, or at or near the superior vena cava. As shown here, object
grasping or removal system 100 includes an outer sheath 110 and a
catch mechanism 120. The catch mechanism is extended from the outer
sheath, so that it may contact, hook, or engage the pacing
lead.
[0034] As illustrated in FIG. 1C, catch mechanism 120 can be
activated, for example by withdrawing it into outer sheath 110, so
as to capture, secure, or engage the pacing lead. While pacing lead
10 is engaged or firmly held by grasping or removal system 100, the
operator may manipulate the removal system so as maneuver the
pacing lead as desired. In some cases, it may be desirable or
beneficial for the physician to administer a pulling action,
wherein the pacing lead is not firmly grasped by the snaring
system, but instead is more loosely engaged by the snaring system,
such that he snaring system allows movement of the pacing lead
through a snaring loop of the system during withdrawal of the lead.
As shown in FIG. 1C, the operator can push grasping or removal
system 100 into or toward the right atrium, in the direction
illustrated by arrow A, thus advancing the pacing lead into or
toward the right atrium. Subsequently, free end 12 of pacing lead
10 is withdrawn from the brachiocephalic vein and into or near the
right atrium, as illustrated in FIG. 1D. Although FIG. 1D
illustrates the situation where a proximal portion of the pacing
lead becomes freed, embodiments of the present invention also
encompass situations where instead, or in addition, a distal
portion of the pacing lead becomes freed. For example, when
physician uses the snaring system to pull on the pacing lead, the
distal end of the pacing lead may become dislodged or separated
from the cardiac tissue.
[0035] The surgeon may adjust the positioning of the object
grasping or removal system on the pacing lead. For example, as
shown in FIG. 1E, catch mechanism 120 can be released or relaxed,
for example by extending it from outer sheath 110. Hence, the catch
mechanism is in an open configuration, and the grasping or object
removal system can be repositioned as desired at another location
along the pacing lead. In the embodiment shown here, grasping or
object removal system is repositioned toward free end 12 of pacing
lead 10. In some cases, the operator may slide the grasping or
removal system along the pacing lead to achieve the desired
repositioning.
[0036] When the grasping or removal system is in the appropriate
location relative to the pacing lead, the operator may activate
catch mechanism 120 so as to firmly secure or grasp pacing lead 10
with removal system 100, as shown in FIG. 1F. The operator may then
pull or withdraw the pacing lead through the jugular vein, and
toward a jugular access site, in direction indicated by arrow A.
The operator may then use the jugular access site to pass a laser
sheath or other lead removal device along grasping or removal
system 100.
[0037] As shown in FIG. 2, an object removal system or grasping
snare 200 can include an outer sheath 210 such as a jacket or tube,
and a catch mechanism 220 such as an snare wire. In some cases,
catch mechanism 220 includes an internal wire having a distal hook.
The internal wire can run along a length of the tube, and the wire
can be configured to move axially within the tube. For example, in
some cases the wire can slide along an inner wire lumen 212 of the
tube. The distal end 222 of the wire 220 which includes the hook
can also be received or disposed within a catch lumen 214 of the
tube. For example, in some cases the distal hook can be extended
from a distal portion 216 of the tube, and retracted back toward or
into the tube. The wire can have a proximal end 224, which extends
from a proximal portion 218 of tube 210, that includes a loop or
pull mechanism 226 such as a pull or torque handle. Outer jacket or
tube 210 can be used by the operator to support or carry snare wire
220, and to provide push, pull, and rotation movements.
[0038] In operation, the physician can use the distal hook of the
wire, for example when it is extended from the tube, to grasp or
snare the free lead. For example, FIG. 3A illustrates an object
removal system or grasping snare 300 having an outer tube 310 and a
snare wire 320. The catch mechanism or snare wire 320 is in an open
position. FIG. 3B also shows snare wire 320 in an open position,
wherein the snare wire is rotated about 180 degrees relative to the
configuration shown in FIG. 3A. A distal hook 322 can assist in
functioning as a grasping snare or a hook snare. When a pacing lead
330 is disposed within hook 322, the operator can pull the snare
wire toward the outer tube, as shown in the closing position or
configuration depicted in FIG. 3C. When the pacing lead is engaged
with or corralled by the hook, the hook can be moved along a length
of the pacing lead, or the hook can be used to maneuver the
positioning of the pacing lead, without applying a significant
pulling or pushing force to the pacing lead, or to an affixed or
embedded portion of the pacing lead. What is more, the operator can
pull snare wire 320 further into tube 310, thus firmly grasping the
lead, as shown in the closed position or configuration depicted in
FIG. 3D. The grasping snare 300 can then be used to push, pull,
twist, or otherwise maneuver pacing lead 330. To release the lead,
the operator can extend the distal hook of the wire from the tube,
for example by pushing it forward relative to the tube, thus
exposing the hook.
[0039] As illustrated in the embodiment depicted in FIG. 4A,
grasping snare system 400 can include an outer tube 410 and an
inner snare wire 420. Snare wire 420 can be rotated relative to
tube 410 as indicated by arrow A, optionally via rotation of a wire
handle 426 as indicated by arrow A shown in FIG. 4B. Relatedly,
snare wire 420 can be translated relative to tube 410 as indicated
by arrow B shown in FIG. 4A, optionally via translation of wire
handle 426 as indicated by arrow B shown in FIG. 4B. In some cases,
snare system 400 can include a seal disposed toward a proximal end
of tube 410, or a luer fitting that accepts a rotating hemostasis
valve.
[0040] As shown in FIG. 4A, tube or outer jacket 410 of snare
system 400 may have two lumens, for example a wire lumen 412 and a
capture lumen 414. According to some embodiments, wire lumen 412
can be laterally offset from a central longitudinal axis 416 of the
outer jacket. For example, wire lumen 412 can be disposed within a
wall 418 of jacket 410. According to such configurations, snare
wire 420 can be constrained to or contained within one side of the
tube. Such tube configuration can also allow a distal hook 422 of
the wire to be rotated outside the axis or silhouette defined by
the outer diameter 419 of the tube, so as to provide a larger
snaring area. Wire lumen 412 within the tube can present a slot
configuration. For example, as shown in FIG. 5A, wire lumen 512a
can present an oval shaped cross section. Relatedly, as shown in
FIG. 5B, wire lumen 512b can present a square or rectangular shaped
cross section.
[0041] Such shaped inner wire lumens 512a, 512b can be formed
during an extrusion process, or reformed with an insert. Relatedly,
the snare wire can include a shaped portion, which presents a
similarly shaped ovular or rectangular profile. For example, as
depicted in FIG. 4A, it is possible to provide a flattened portion
423 at or near the distal curve section 422 of the snare wire 420
to key it into the lumen or slot 412 in the side or wall of outer
jacket 410. In this way, snare wire 420 can be keyed with tube 410.
Such modifications can increase the surface area on the outer or
top portion of the loop 422 to prevent or inhibit snare wire 420
from cutting into or stripping the pacing lead. Hence, a flattened
or shaped portion can be placed on the distal section of the wire
to key the snare wire to the tube. A section of the wire proximal
to the flattened or shaped portion can be round or rounded in
shape, so as to allow the snare wire to be rotated relative to the
tube within the inner wire aperture, when the flattened or shaped
section is distal to the tube lumen. In addition to flattened
shapes, the snare wire and slot 412 may present square
cross-section shapes, rectangular cross-section shapes, and other
complementary interlocking or keyed shapes. In some embodiments,
such keyed snaring systems may include roller bearings or sleeves
as described elsewhere herein, for example with reference to FIGS.
9 to 11C, and 15 to 15C.
[0042] According to some embodiments, snare wire 420 or loop area
422 can include a slip coating or reduced friction surface, to
allow the snare to slide along the lead, for example when the snare
is being opened or closed. In some cases, such a coating or surface
can include PTFE, Teflon, Teflon spray, paralene, or any suitable
reduced-friction spray, tubing, coating, or solution.
[0043] Outer jacket or tube 410 can be constructed of one or
materials including Pebax, ABS, PEEK, FEP, PE, Nylon, a Pebax braid
matrix, or the like. The outer diameter (OD) of the tube can be
within a range from about 0.090 inches to about 0.160 inches. In
some cases, the outer diameter of the tube can be sized so as to
allow a laser sheath, which may be 12 Fr to 16 Fr, to pass over the
snaring assembly. For example, the outer diameter can be sized to
allow a 12 Fr laser sheath pass over the tube 410. The snare wire
can be constructed of one or more materials such as stainless
steel, NiTi, or the like. The outer diameter (OD) of the wire can
be within a range from about 0.010 inches to about 0.050 inches.
The wire can be configured to provide sufficient strength to pull
on a pacing lead while providing sufficient flexibility to navigate
the patient's anatomy.
[0044] As shown in FIG. 6, embodiments of the present invention
encompass mechanisms that can deflect a distal end of the outer
tube. Snaring system 600 includes an outer tube 610, a snare wire
or capture mechanism 620, and a deflection mechanism 650. The
deflection mechanism may include, for example, a pull wire or a
steering tendon 660. Deflection mechanism 650 can provide to the
snare system an additional degree of freedom while manipulating the
snare system to grasp a pacing lead. In some cases, a deflection
mechanism can include a tendon wire that is housed in a wall of
outer tube 610, for example within a deflection mechanism lumen
616, and anchored at some point distal, for example at an anchor
point 618. According to some embodiments, the location of anchor
point 618 along the length of tube 610 can be determined by the
radius of curvature desired during operation of the deflection
mechanism. For example, as the anchor point is located more closely
to a distal end 619 of tube 610, it is possible to achieve a bend
in tube 610 having a smaller radius of curvature when actuating the
deflection mechanism. According to some embodiments, anchor point
618 can be located within 20 cm of the distal end of tube 610. In
some cases, anchor point 618 may include an embedded eyelet or an
anchor band. Anchor point 618 can serve to fix a distal portion of
the pull wire relative to the outer tube.
[0045] As depicted in FIG. 6, deflection can be effected by
applying tension to a proximal end 652 of the tendon wire, for
example by pulling the wire in the direction indicated by arrow A,
which in tum causes the distal end of the tube to deflect in the
direction indicated by arrow B. The tendon wire can have a diameter
within a range from about 0.005 inches to about 0.030 inches,
according to some embodiments. The tension can be applied by
through the use of a mechanical mechanism or through the use of
manual force provided directly by the user. In some cases, a
mechanical deflection mechanism can include a screw, a cam or
cylindrical disk, a lever, or other mechanical means to tension a
wire. A mechanical deflection mechanism could be mounted in a
housing to create a handle. According to some embodiments, a handle
can be configured to lock the tube in a deflected configuration as
desired during a surgical procedure, and until the operator
unlocked the tube from the deflected orientation.
[0046] According to some embodiments, a snare system may include a
pre-shaped outer tube that can be straightened or shaped by
advancing a straight or shaped mandrel through a lumen in the wall
of the outer tube. The degree of straightening, or deflection, can
be controlled by the distance or extent to which the mandrel is
advanced distally into the wall or lumen of the outer tube. In some
cases, a mandrel can be integrated with the outer tube, yet allow
it to be slidable. In some cases, a mandrel can be an auxiliary
member that is removable. A distal end of the mandrel can be made
with a ball-end tip to prevent or inhibit it from perforating the
outer tube when it is advanced.
[0047] Snaring systems which include shaped wire element such as
those depicted in FIGS. 2, 3A to 3D, 4A, and 6 are well suited for
loosely engaging and maneuvering a pacing lead without subjecting
the pacing lead to significant pulling forces. Such systems are
particularly useful in pacing lead removal methods such as those
described herein with reference to FIGS. 7A and 7B. For example, in
some cases, it may be desirable or beneficial for the physician to
administer a pulling action, wherein the pacing lead is not firmly
grasped by the snaring system, but instead is more loosely engaged
by the snaring system, such that the snaring system allows movement
of the pacing lead through a snaring loop of the system as the
system is navigated or manipulated by the physician.
[0048] As noted above, exemplary lead extraction procedures can
involve a femoral or jugular approach to accessing or removing the
lead, in contrast to a superior or lead pocket approach. FIG. 7A
illustrates aspects of a lead snaring or removal process, according
to embodiments of the present invention. As depicted here, pacing
lead 701 is disposed within the patient, such that a distal portion
702 of pacing lead 701 is secured in the patient's right ventricle.
A proximal portion 703 of pacing lead is disposed at or near the
pacemaker pocket of the patient. Snaring system 710 can be used to
snare, grasp, or otherwise engage the pacing lead. For example, an
elongate element or hooked wire of the snaring system can be
inserted into the vasculature through a snaring system sheath,
either from a jugular vein or femoral vein access site. The distal
hook or loop can be placed near the pacing lead at or near the
vicinity of the superior vena cava. A distal loop 712 of snaring
system 710 can be used to hook a central portion 704 of the pacing
lead, optionally by maneuvering or manipulating a control handle
714 of the snaring system. For example, the snaring wire can be
rotated via a handle or pin vice 714 so that a hook tag end of
distal portion 712 catches the lead. The operator can pull up on
the snare wire or snaring system to cause the pacing lead to slide
into the enclosed area of the distal hook.
[0049] As shown in FIG. 7B, when the distal loop or hook 712 of
snaring system 710 has caught the pacing lead, the snaring system
can be retracted or pulled up in the direction indicated by arrow
A, so as to withdraw proximal portion 703 of the pacing lead away
from the pacemaker pocket, and into the jugular vein. During
withdrawal of the snaring system, distal loop 712 of the snaring
system can slide along a length of the pacing lead, from central
portion 704 toward proximal portion 703, as indicated by arrow B.
Although FIGS. 7A and 7B illustrate the situation where a proximal
portion of the pacing lead becomes freed, embodiments of the
present invention also encompass situations where instead, or in
addition, a distal portion of the pacing lead becomes freed. For
example, when physician uses the snaring system to pull on the
pacing lead, the distal end of the pacing lead may become dislodged
or separated from the cardiac tissue.
[0050] Optionally, as discussed elsewhere herein, a sheath can be
placed over the snaring wire and advanced over the tag end of the
distal hook, so as to cinch or secure the pacing lead to the
snaring system. The sheath and snaring wire can then be pulled to
free the proximal portion of the pacing lead. Once free, the
snaring wire and sheath can be pulled out of the body access site
along with the proximal end of the pacing lead. With the proximal
end of the pacing lead disposed outside of the body, the entire
pacing lead can be extracted via lead extraction techniques, for
example via laser lead extraction. To disengage the snaring system
from the pacing lead, the operator can push and rotate the snaring
wire to release the hook from the pacing lead.
[0051] FIG. 8 depicts a snaring system 800 according to embodiments
of the present invention. Snaring system 800 includes an elongate
element or wire 810 having a proximal portion 812 and a distal
portion 814. System 800 can include a pin vice or handle 820
coupled with proximal portion 812 of elongate element 810. As shown
here, distal portion 814 of elongate element 810 includes a looped
or hooked portion 815. Distal portion 814 can also include a tag
end 816. According to some embodiments, elongate element 810
includes a stainless steel wire having a diameter of about 0.020
inches. Looped portion 815 can have a length L of about 0.5 inches
and a width W of about 0.2 inches. In some cases, tag end 816 can
have a length LT of about 0.25 inches. In some cases, tag end 816
can have a length LT of about 0.50 inches.
[0052] FIG. 9 depicts a snaring system 900 according to embodiments
of the present invention. Snaring system 900 includes an elongate
element or wire 910 having a proximal portion 912 and a distal
portion 914. System 900 can include a handle 920 coupled with
proximal portion 912 of elongate element 910. As shown here, distal
portion 914 of elongate element 910 includes a looped or hooked
portion 915. Distal portion 914 can also include a tag end 916.
System 900 further includes a bearing or sleeve 919 disposed about
a section of distal portion 914. In some cases, bearing 919 can
rotate about elongate element 910. Bearing 919 can provide reduced
friction between elongate element 910 and a pacing lead. Elongate
element 910 can include one or more bends 911 which can enhance
steerability of the snaring system. A bearing element can include a
metal material, such as stainless steel, titanium, or the like. In
some cases, a bearing element may include a plastic material, such
as Teflon, nylon, polycarbonate, high-density polyethylene (HDPE),
ultra high molecular weight polyethylene (UHMWPE), or the like. A
bearing or sleeve can have a cylindrical or tubular shape. For
example, a bearing can present a cylindrical shape, having a
diameter with a range from about 0.04 inches to about 0.12 inches.
FIG. 10 illustrates a snaring system 1000 which includes two
bearings or sleeves 1019a, 1019b disposed about an elongate element
1010. As shown here, bearing or sleeve 1019a may define, for
example by way of an internal lumen, a central longitudinal axis
1019ai, and bearing or sleeve 1019b may define, for example by way
of an internal lumen, a central longitudinal axis 1019bi. Axis
1019ai may be angularly offset from axis 1019bi. FIG. 11
illustrates a snaring system 1100 which includes three bearings or
sleeves 1119a, 1119b, 1119c disposed about an elongate element
1110. One or more of the bearings may present a spherical shape.
For example, bearing 1119b can present a spherical shape having a
diameter within a range from about 0.04 inches to about 0.10
inches. Snaring systems having roller bearings or sleeves can allow
a physician to apply significant pulling forces to the catheter,
while still maintaining an operable engagement between the snaring
system and the pacing lead. The roller bearing or sleeve can act to
dissipate a portion of the applied force, such that a reduced
amount of force is applied to the pacing lead itself.
[0053] As depicted in FIG. 8, elongate element 810 can have a
radiused bottom or distal looped portion. Relatedly, as depicted in
FIG. 9, elongate element 910 can have a straight bottom or distal
looped portion. As shown in FIG. 10, elongate element 1010 can have
an angled bottom or distal looped portion, such that a first
straight section is angularly offset from a second straight section
by about 90 degrees. Accordingly, the snaring system, which
presents two roller bearings 1019a, 1019b that can simultaneously
contact a pacing lead, provides roller bearings edges that are
angularly offset from one another by about 90 degrees. As shown in
FIG. 11, elongate element Ill 0 can have an angled bottom or distal
looped portion, such that a first straight section is angularly
offset from a second straight section by about 90 degrees.
Accordingly, the snaring system, which presents three roller
bearings 1119a, 1119b, 1119c that can simultaneously contact a
pacing lead, provides cylindrical roller bearings edges that are
angularly offset from one another by about 90 degrees. Typically,
the bottom or distal looped portions are appropriately sized to
accommodate a pacing lead. For example, as shown in FIG. 8, in some
cases a bottom or distal looped portion may have a length L that is
about twice as long as a width W. To accommodate a large
defibrillator lead having a diameter of about 0.170 inches, for
example, the looped or hooked portion 815 may have a length L of
about 0.5 inches and a width W of about 0.2 inches. In some cases,
the incorporation of an increased number of rollers or bearings,
for example as depicted in FIG. 11, allows the operator to pull the
snaring system along a pacing lead using a correspondingly reduced
amount of force.
[0054] Snaring systems which include a roller bearing or sleeve as
described herein are well suited for loosely engaging and
maneuvering a pacing lead without subjecting the pacing lead to
significant pulling forces. Such systems are particularly useful in
pacing lead removal methods such as those described herein with
reference to FIGS. 7A and 7B. For example, in some cases, it may be
desirable or beneficial for the physician to administer a pulling
action, wherein the pacing lead is not firmly grasped by the
snaring system, but instead is more loosely engaged by the snaring
system, such that he snaring system allows movement of the pacing
lead through a snaring loop of the system as the system is
navigated or manipulated by the physician.
[0055] Hence, snare systems can include a closed hook and tag end
which can be used to grab a pacing lead or otherwise allow the
pacing lead entry into the hook. An elongate element or wire may
include a medical grade wire constructed of stainless steel,
Nitinol, or the like. The elongate element or wire can be tapered
from a larger diameter on a proximal portion or end to smaller
diameter on a distal portion or end, and may have varying diameters
along the length of the wire to add flexibility or strength where
needed or desired. The construction can also include a central core
mandrel, which may also be tapered or of varying diameter, which in
tum is covered with a coil. A tag end may present an atraumatic
configuration. In some cases, a tag end may terminate in a ball
end. In some cases, a tag end may terminate in a pig tail
configuration or a flexible coil. Atraumatic configurations can
help to prevent or inhibit perforation of the vasculature.
[0056] FIG. 11A illustrates side view of a snaring system 1100a
according to embodiments of the present invention. As shown here,
snaring system 1100a includes an elongate element or wire 1100a
having a proximal portion 1112a and a distal portion 1114a. System
1100a can include a pin vice or handle (not shown) coupled with
proximal portion 1114a of elongate element 1100a. As shown here,
distal portion 1114a of elongate element 1100a includes a looped or
hooked portion 1115a. Distal portion 1114a can also include a tag
end 1116a. According to some embodiments, elongate element 1100a
includes a stainless steel wire having a diameter of about 0.020
inches. Looped portion 1115a can have a first length L1 of about
0.41 inches and a second length L2 of about 0.19 inches. As shown
here, tag end 1116a extends from a central portion 1113a of
elongate element 1100a to a distance ET of about 0.22 inches.
Snaring system 1100a includes three bearings or sleeves 1120a,
1120b, 1120c disposed about an elongate element 1100a. Snaring
system 1100a also includes a distal bead or spherical mechanism
1130a disposed on a distal portion of elongate element 1110a.
[0057] Bearing 1120a presents a cylindrical or barrel shape having
a diameter within a range from about 0.04 inches to about 0.10
inches. Optionally, bearing 1120a can have a diameter of about 0.07
inches. In some cases, bearing 1120a can have a length of about
0.12 inches. As shown here, an end portion of bearing 1120a
presents a radius of curvature of about 0.2 inches. Bearing 1120b
presents a spherical or oblate shape having a diameter within a
range from about 0.04 inches to about 0.10 inches. Optionally,
bearing 1120b can have a diameter of about 0.07 inches. In some
cases, bearing 1120b can have a length of about 0.06 inches.
Bearing 1120c presents a cylindrical or barrel shape having a
diameter within a range from about 0.04 inches to about 0.10
inches. Optionally, bearing 1120c can have a diameter of about 0.07
inches. In some cases, bearing 1120c can have a length of about
0.19 inches. As shown in FIG. 11A, elongate element 1100a can have
an angled bottom or distal looped portion, such that a first
section 1151a is angularly offset from a second section 1152a. In
tum, second section 1152a is angularly offset from a third section
1153a, which is angularly offset from a fourth section 1154a.
Further, fourth section 1154a is angularly offset from a fifth
section 1155a, which is angularly offset from a sixth section
1156a. As shown here, fourth section 1154a and fifth section 1155a
of elongate element 1110a define an angle of about 157.4 degrees,
and fifth section 1155a and sixth section 1156a of elongate element
1110a define an angle of about 130 degrees. Distal bead or
spherical mechanism 1130a can present a radius of curvature of
about 0.03 inches. Typically, the bottom or distal looped portions
of the elongate element, optionally in combination with the
bearings, are appropriately sized or configured to accommodate a
pacing lead.
[0058] FIG. 11B illustrates a perspective view of a snaring system
1100b according to embodiments of the present invention. As shown
here, snaring system 1100b includes an elongate element or wire
1110b having a proximal portion 1112b and a distal portion 1114b.
System 1100b can include a pin vice or handle (not shown) coupled
with proximal portion 1114b of elongate element 1110b. As shown
here, distal portion 1114b of elongate element 1110b includes a
looped or hooked portion 1115b. Distal portion 1114b can also
include a tag end 1116b. According to some embodiments, elongate
element 1110b includes a stainless steel wire having a diameter of
about 0.020 inches. Elongate element 1110b and looped portion 1115b
can present geometrical configurations similar to those described
above with reference to FIG. 11A. Snaring system 1100b includes
three bearings or sleeves 1121a, 1121b, 1121c disposed about an
elongate element 1110b. Snaring system 1110b also includes a distal
bead or spherical mechanism 1130b disposed on a distal portion of
elongate element 1110b. The bearings and bead mechanisms can
present geometrical configurations similar to those described above
with reference to FIG. 11A.
[0059] FIG. 11C illustrates a top view of a snaring system 1100c
according to embodiments of the present invention. As shown here,
snaring system 1100c includes an elongate element or wire 1110c
having a proximal portion 1112c and a distal portion 1114c. System
1100c can include a pin vice or handle (not shown) coupled with
proximal portion 1114c of elongate element 1110c. As shown here,
distal portion 1114c of elongate element 1110c includes a looped or
hooked portion 1115c. Distal portion 1114c can also include a tag
end 1116c. According to some embodiments, elongate element 1110c
includes a stainless steel wire having a diameter of about 0.019
inches. Elongate element 1110c and looped portion 1115c can present
geometrical configurations similar to those described above with
reference to FIG. 11A. Snaring system 1100c includes three bearings
or sleeves 1122a, 1122b, 1122c disposed about an elongate element
1110c. Snaring system 1100c also includes a distal bead or
spherical mechanism 1130c disposed on a distal portion of elongate
element 1110c. The bearings and bead mechanisms can present
geometrical configurations similar to those described above with
reference to FIG. 11A. As shown here, tag end 1116c can be offset
from a central portion 1113c of elongate element 1110c at an angle
of about 5 degrees.
[0060] According to some embodiments, a hook can be radiopaque, for
example by either being constructed of a base material having a
suitable thickness, or by incorporating radiopaque material. In
some cases, a hook or elongate element can contain radiopaque
marker bands placed at appropriate or desired locations along the
element. In some cases, a hook or coil can include a radiopaque
metal such as Pt, Au, Ir, Tungsten, or the like. As noted, snaring
systems can also include a hook or elongate element in conjunction
with one or more bearing surfaces. A bearing or sleeve can include
a low friction material such as Teflon, PE, nylon, or the like,
optionally in a tubular or sheath configuration. The bearing or
sleeve can be disposed or placed over the wire or elongate element.
Optionally, a bearing or sleeve can be placed or positioned over a
hard metal or plastic component mounted on the wire or elongate
element, and can be designed or configured to rotate when a pacing
lead is pulled out of the body with the snare system.
[0061] According to some embodiments, a snare system can include an
outer jacket, such as a plastic sheath. FIG. 12A illustrates
aspects of a snaring system 1200 according to embodiments of the
present invention. Snaring system 1200 includes an outer jacket or
sheath 1210 and a capture mechanism or elongate element 1220. An
operator can position the snaring system so as to capture a portion
of a pacing lead 1250 with a hook tag end 1226 of the elongate
element. As shown in FIG. 12B, an operator can maneuver the snaring
system, for example by pulling and rotating the elongate element,
so as to enclose pacing lead 1250 within a distal loop 1225 of the
elongate element. As shown in FIG. 12C, an operator can maneuver
the snaring system, for example by advancing or translating sheath
1210 relative to elongate element 1220, so as to bring distal loop
1225 toward sheath 1210, such that hook tag end 1226 is received
within the sheath, and pacing lead 1250 is securely grasped by
distal loop 1225. In some instances, distal loop 1225 operates to
squeeze or press the pacing lead against a distal end 1212 of
sheath 1210.
[0062] Snaring systems which include a hook tag end as described
herein are well suited for loosely engaging and maneuvering a
pacing lead without subjecting the pacing lead to significant
pulling forces. Such systems are particularly useful in pacing lead
removal methods such as those described herein with reference to
FIGS. 7A and 7B. For example, in some cases, it may be desirable or
beneficial for the physician to administer a pulling action,
wherein the pacing lead is not firmly grasped by the snaring
system, but instead is more loosely engaged by the snaring system,
such that he snaring system allows movement of the pacing lead
through a snaring loop of the system as the system is navigated or
manipulated by the physician.
[0063] According to some embodiments, outer jacket or sheath 1210
of the snaring system can have an inner or central lumen. In some
cases, sheath 1210 can have an inner diameter of about 0.18 inches
and an outer diameter of about 0.22 inches. Sheath 1210 can have a
bevel 1211 disposed at distal end 1212. In some cases, sheath 1210
can present a 12 Fr sheath. In some cases, sheath 1210 can be
embodied by an outer sheath which is used in conjunction with a
laser sheath.
[0064] FIG. 13A shows an outer sheath 1300 of a snaring system
according to embodiments of the present invention. As shown here,
sheath 1300 has a length L of about 32 cm to about 33 cm. Sheath
1300 includes an angled distal end 1310 that presents an angle a of
about 40 degrees to about 45 degrees. Both distal end 1310 and
proximal end 1320 are beveled or chamfered, to reduce or remove
burrs or frays that may be present. As depicted in FIG. 13B, sheath
1300 can have an inner diameter ID of about 0.176 inches, and an
outer diameter OD of about 0.2205 inches.
[0065] Experimental Results
[0066] Selected systems and methods were tested for performing
pacing lead extraction via a jugular access site. For a jugular
approach, it is possible to snare the implanted pacing lead and
pull a proximal portion of the pacing lead up through the right
jugular vein. A pacing lead is typically long enough to extend out
the neck, and allow placement of a locking stylet. A jugular
approach presents a straight anatomic approach to binding sites in
the superior vena cava and ventricle areas. It is possible to free
the pacing lead in the subclavian and innominant vein with a
sheath, which can also be used as part of a snaring method to
remove the pacing lead via the jugular vein.
[0067] A glass venous heart model was fitted with Tygon tubing of
approximately 1'' diameter, to exceed the model to the jugular and
femoral entry sites. Small and medium simulated leads were placed
in the model in the superior configuration and secured on the
distal end by hemostats at the ventricular apex.
[0068] In an initial trial, a pigtail catheter that was tested with
the heart model. The pigtail catheter was inserted though the
jugular access site, in an attempt to grab the pacing lead from
above. This trial was not successful, because the pigtail curve was
not strong enough to pull the pacing lead up and through.
[0069] FIG. 14A illustrates a snaring system 1400 that was also
tested with the heart model. Snaring system 1400 includes an
elongate element 1410 having a distal end 1420 and a proximal end
1430. System 1400 also includes a pin device 1440 coupled with
proximal end 1430 of the elongate element. Distal end 1420 includes
a loop 1422 and a tag 1424. The elongate element 1410 includes a
stainless steel wire having a 0.020 inch diameter. As depicted
herein, distal section 1420 includes a straight bend 1421 which
allows engagement of tag end 1424 with a pacing lead, for example,
when rotating the hook or loop 1422 via rotation of pin vice 1440.
Once tag 1424 is engaged with the pacing lead, a slight pull
applied to the snaring system can secure the pacing lead in loop
1422. The first attempt using this design was successful in pulling
the pacing lead up and out the jugular.
[0070] As depicted in FIG. 14B, snaring system 1400 may also
include an outer sheath 1450. In use, sheath 1450 can be employed
to secure loop 1422, for example by receiving the tag within a
central lumen or distal opening 1452 of the sheath. In this way,
snaring system 1400 can further cinch or grasp a pacing lead 1460.
The tag end may remain covered by sheath 1450 while the snaring
system is used to remove or maneuver the pacing lead.
[0071] FIG. 15 shows aspects of a snaring system 1500 which
provided excellent results when used in the heart model. The
snaring system includes an elongate element 1510 having a distal
end 1520 and a proximal end 1530. Distal end 1520 includes a loop
1522 and a tag 1524. Snaring system 1500 also includes a sleeve or
bearing 1560 disposed toward distal end 1520 of elongate element
1510. For example, bearing 1560 can be disposed about a portion of
loop1522. It was discovered that by using this system, the pacing
lead could be maneuvered up and out the jugular vein of the in
vitro model, using reduced pulling forces. Moreover, the elongate
element can conveniently fit within a 12 Fr. outer sheath, and can
be used to effectively remove or maneuver a 12 Fr. pacing lead. As
shown here, bearing 1560 is disposed toward a distal end, or
bottom, of loop or hook 1522.
[0072] FIG. 15A illustrates a side view of a snaring system 1500a
according to embodiments of the present invention. The snaring
system includes an elongate element 1510a having a distal portion
1520a and a proximal portion 1530a. Distal portion 1520a includes a
loop 1522a and a tag 1524a. Snaring system 1500a also includes a
sleeve or bearing 1560a disposed toward distal portion 1520a of
elongate element 1510a. For example, bearing 1560a can be disposed
about a portion of loop 1522a. Bearing 1560a can have a length of
about 0.13 inches, and may present a radius of curvature of about
0.2 inches. As shown here, bearing 1560a is disposed toward a
distal end, or bottom, of loop or hook 1522a. Distal portion 1520a
can also include a tag end 1524a. According to some embodiments,
elongate element 1510a includes a stainless steel wire having a
diameter of about 0.020 inches. In some cases, tag end 1524a can
extend from a central portion 1513a of elongate element 1510a to a
distance of about 0.24 inches. Tag end 1524a can include a distal
curve or bend 1525a.
[0073] As depicted in FIG. 15A, elongate element 1510a can have an
angled bottom or distal looped portion, such that a first section
1551a is angularly offset and separated from a third section 1553a
by a second section 1552a. In tum, third section 1553a is angularly
offset and separated from a fifth section 1555a by a fourth section
1554a. Further, fifth section 1555a is angularly offset and
separated from a seventh section 1557a by a sixth section 1556a.
Second section 1552a can present a radius of curvature of about
0.07 inches, and fifth section 1555a can have a length of about
0.34 inches. Relatedly, first section 1551a can be disposed
parallel to fifth section 1555a, such that first section 1551a and
fifth section 1555a are separated by a distance of about 0.18
inches. First section 1551a and seventh section 1557a can be
angularly offset, so as to define an angle of about 129.6 degrees.
As shown here, rotatable bearing 1560a can be disposed on a section
1553a of loop 1522a, and loop 1522a can include a section 1555a
distal to the section 1553a, and a section 1551a proximal to the
section 1553a. Sections 1551a and 1555a can be in substantial
parallel alignment. Relatedly, section 1553a can be in substantial
perpendicular alignment with each of the sections 1551a and
1555a.
[0074] FIG. 15B illustrates a perspective view of a snaring system
1500b according to embodiments of the present invention. As shown
here, snaring system 1500b includes an elongate element or wire
1510b having a proximal portion 1530b and a distal portion 1520b.
System 1500b can include a pin vice or handle (not shown) coupled
with proximal portion 1530b of elongate element 1510b. As shown
here, distal portion 1520b of elongate element 1510b includes a
looped or hooked portion 1522b. Distal portion 1520b can also
include a tag end 1524b. According to some embodiments, elongate
element 1510b includes a stainless steel wire having a diameter of
about 0.020 inches. Elongate element 1510b and looped portion 1522b
can present geometrical configurations similar to those described
above with reference to FIG. 15A. Snaring system 1500b includes a
bearing or sleeve 1560b disposed about elongate element 1510b.
Snaring system 1500b also includes a distal curve or bend mechanism
1525b disposed on a distal portion of elongate element 1510b. The
bearings and bend mechanisms can present geometrical configurations
similar to those described above with reference to FIG. 15A.
[0075] FIG. 15C illustrates a bottom view of a snaring system 1500c
according to embodiments of the present invention. As shown here,
snaring system 1500c includes an elongate element or wire 1510c
having a proximal portion 1530c and a distal portion 1520c. System
1500c can include a pin vice or handle (not shown) coupled with
proximal portion 1530c of elongate element 1510c. As shown here,
distal portion 1520c of elongate element 1510c includes a looped or
hooked portion 1522c. Distal portion 1520c can also include a tag
end 1524c. According to some embodiments, elongate element 1510c
includes a stainless steel wire having a diameter of about 0.019
inches. Elongate element 1510c and looped portion 1552c can present
geometrical configurations similar to those described above with
reference to FIG. 15A. Snaring system 1500c includes a bearing or
sleeve 1560c. In some cases, bearing 1560 has an inner diameter of
about 0.02 inches, and an outer diameter of about 0.07 inches.
Snaring system 1500c also includes a distal bend or curve mechanism
1525c disposed on a distal portion of elongate element 1510c. The
bearing and bend mechanisms can present geometrical configurations
similar to those described above with reference to FIG. 15A. As
shown here, tag end 1524c can be offset from a central portion
1513c of elongate element 1510c at an angle of about 5 degrees.
[0076] Hence, snaring systems according to embodiments of the
present invention are well suited for use in grasping or
maneuvering pacing leads. Such systems can be conveniently used in
conjunction with a locking stylet which provides reliable
unlocking. Systems may also be used in conjunction with or
incorporate introducers placed at an access site. For example, a
snaring system can be used with an introducer at a jugular entry
site. In some cases, an introducer may include a valve. Snaring
systems may be reversible, and thus can be used to easily grasp and
release a pacing lead. Moreover, snaring systems may include a tag
end or other atraumatic feature which provides protection at or
near a distal portion of the system, and thus prevents or reduces
the likelihood of damaging a patient tissue.
[0077] According to some embodiments, a snare can be inserted into
the jugular vein of a patient. The snare can be used to grasp the
pacing lead and push it down into the right atrium. Once the pacing
lead is positioned as desired in the right atrium, the snare may be
slid down the pacing lead so that it may grasp the pacing lead near
the free end. Once grasped near its free end, the pacing lead may
be pulled out through the jugular vein. In some cases, grasping
snare wires can be extended or advanced through a wall of a
catheter body.
[0078] While the exemplary embodiments have been described in some
detail, by way of example and for clarity of understanding, those
of skill in the art will recognize that a variety of modification,
adaptations, and changes may be employed. Hence, the scope of the
present invention should be limited solely by the appending
claims.
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