U.S. patent application number 13/333783 was filed with the patent office on 2012-04-19 for endocardial lead removing apparatus.
Invention is credited to Wade A. Bowe, Patrick Hunkins, Brian Kagarise, Christopher Reiser, Kevin D. Taylor.
Application Number | 20120095479 13/333783 |
Document ID | / |
Family ID | 44477143 |
Filed Date | 2012-04-19 |
United States Patent
Application |
20120095479 |
Kind Code |
A1 |
Bowe; Wade A. ; et
al. |
April 19, 2012 |
Endocardial Lead Removing Apparatus
Abstract
The invention provides an apparatus having a tubular member for
receiving an endocardial lead implanted within a patient's body.
Disposed generally at a distal end of the tubular member is at
least one blade or cutting surface. An adjustment mechanism moves
the blade between retracted and extended positions to engage the
cutting surface with the endocardial lead to cut the lead. Once
severed, the cut portion of the lead remains within an inner
channel of the tubular member and the apparatus and cut portion of
the lead are removed from within the patient. Various embodiments
include the blade pivotally connected to the distal end of the
tubular member and activated by a wire adjustment mechanism. Others
include a metallic wire for slicing through the lead. Still others
include a pneumatically actuated adjustment mechanism that inflates
to move the blade and engage the cutting surface with the lead.
Inventors: |
Bowe; Wade A.; (Colorado
Springs, CO) ; Hunkins; Patrick; (Littleton, CO)
; Kagarise; Brian; (Colorado Springs, CO) ;
Reiser; Christopher; (Stevenson Ranch, CA) ; Taylor;
Kevin D.; (Colorado Springs, CO) |
Family ID: |
44477143 |
Appl. No.: |
13/333783 |
Filed: |
December 21, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11190550 |
Jul 27, 2005 |
8097012 |
|
|
13333783 |
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Current U.S.
Class: |
606/129 |
Current CPC
Class: |
A61B 17/00008 20130101;
A61B 17/32 20130101; A61B 17/3468 20130101; A61B 2017/00358
20130101; A61B 17/50 20130101 |
Class at
Publication: |
606/129 |
International
Class: |
A61B 19/00 20060101
A61B019/00 |
Claims
1-49. (canceled)
50. An endocardial lead removing apparatus for removing a lead
implanted within a patient, comprising: a tubular member having a
proximal end and a distal end; at least one blade pivotally
connected to said distal end and moveable between a retracted
position and an extended position; and an adjustment mechanism for
pivoting said at least one blade between said retracted and
extended positions.
51. The apparatus of claim 50, wherein said at least one blade is
coupled to said distal end of said tubular member by at least one
pin to pivot said at least one blade between said retracted and
extended positions.
52. The apparatus of claim 50, wherein said adjustment mechanism
includes an outer sheath receiving said tubular member and moveable
longitudinally along said tubular member.
53. The apparatus of claim 52, wherein a distal end of said outer
sheath engages said at least one blade to pivot from said retracted
position to said extended position.
54. The apparatus of claim 50, wherein said adjustment mechanism
includes a wire attached to said at least one blade and disposed
within said tubular member such that applying tension to said wire
pivots said at least one blade from said retracted position to said
extended position.
55. The apparatus of claim 54, wherein a proximal end of said wire
is joined to a handle.
56. The apparatus of claim 50, wherein said tubular member is
metallic.
57. The apparatus of claim 50, wherein said at least one blade is
generally arcuate to define an inner cutting surface.
58. An endocardial lead removing apparatus for removing a lead
implanted within a patient, comprising: a tubular member having a
proximal end and a distal end; and a first and second blade
pivotally connected to said distal end and moveable between a
retracted position and an extended position.
59. The apparatus of claim 58, wherein said first and second blade
are generally arcuate to define an inner cutting surface.
60. The apparatus of claim 58, wherein said first and second blade
are operatively coupled to a pull wire and wherein said is pull
wire is configured to pivot said first and second blade from said
retracted position to said extended position upon application of
tension force.
61. The apparatus of claim 58, further comprising an adjustment
mechanism for pivoting said first and second blade between said
retracted and extended positions.
62. The apparatus of claim 58, further comprising an adjustment
mechanism for pivoting said first and second blade between said
retracted and extended positions.
63. The apparatus of claim 60, wherein the pull wire extends from
an inner cavity of the tubular member.
64. The apparatus of claim 60, further comprising a handled coupled
to a proximal end of the pull wire.
65. The apparatus of claim 58, wherein an inner portion of the
tubular member is configured to receive a severed portion of the
lead.
66. An endocardial lead removing apparatus for removing a lead
implanted within a patient, comprising: a tubular member having a
proximal end and a distal end; at least one blade pivotally
connected to said distal end and moveable between a retracted
position and an extended position, wherein the at least one blade
is configured to sever the lead in the extended position.
67. The apparatus of claim 66, wherein an inner portion of the
tubular member is configured to receive a severed portion of the
lead.
68. The apparatus of claim 66, wherein said at least one blade is
operatively coupled to a pull wire and wherein said is pull wire is
configured to pivot said at least one blade said retracted position
to said extended position upon application of tension force.
69. The apparatus of claim 66, wherein said at least one blade is
generally arcuate to define an inner cutting surface.
70. The apparatus of claim 68, further comprising a handled coupled
to a proximal end of the pull wire.
Description
FIELD OF THE INVENTION
[0001] This invention relates generally to an endocardial lead
removing apparatus and, more particularly, to an apparatus that
cuts the endocardial lead and, in some embodiments, captures the
cut portion to remove the lead from the patient's body.
BACKGROUND OF THE INVENTION
[0002] In the past, various types of endocardial leads and
electrodes have been introduced into different chambers of a
patient's heart, including among other locations, the right
ventricle, right atrial appendage, and atrium, as well as the
coronary sinus. These flexible leads are often composed of an
insulator sleeve that contains an implanted helical coil conductor
that is attached to an electrode tip. This electrode is placed in
contact with myocardial tissue by passage through a venous access,
often the subclavian vein or one of its tributaries, which leads to
the endocardial surface of the heart chambers. The tip with the
electrode contact is held in place by trabeculations of myocardial
tissue. In some cases, active fixation leads are fastened by screw
into the myocardial tissue.
[0003] The tips of many available leads often include flexible
tines, wedges, or finger-like projections which extend radially
outward and usually are molded from and integral with the
insulating sheath of the lead. These tines or protrusions allow
surrounding growth of tissue in chronically implanted leads to fix
the electrode tip in position in the heart and prevent dislodgement
of the tip during the life of the lead. In "acute placement" of the
electrode or lead tip, a blood clot forms about the flanges or
tines (due to enzymes released as a result of irritation of the
trabeculations of myocardial tissue by the presence of the
electrode tip) until scar tissue eventually forms, usually in three
to six months. The tines or wedges or finger-like projections allow
better containment by the myocardial trabeculations of muscle
tissue and prevent early dislodgement of the lead tip.
[0004] Although the state of the art in implemented pulse generator
or pacemaker technology and endocardial lead technology has
advanced considerably, endocardial leads nevertheless occasionally
fail, due to a variety of reasons, including breakage of a lead,
insulation breaks, breakage of the inner helical coil conductor and
an increase in electrode resistance. Furthermore, in some
instances, it may be desirable to electronically stimulate
different portions of the heart than are presently being stimulated
with the leads already implanted. There are a considerable number
of patients who have one or more, and sometimes as many as four or
five, unused leads in their veins and heart.
[0005] Although it obviously would be desirable to easily remove
such unused leads, in the past surgeons usually have avoided
attempts to remove inoperative leads because the risk of removing
them exceeded the risk of leaving them in. The risks of leaving
unused myocardial leads in the heart and venous path include
increased likelihood that an old lead may facilitate infection,
which in turn may necessitate removal of the lead to prevent
continued bacteremia and abcess formation. Furthermore, there is an
increased likelihood of the formation of blood clots in the atrial
chamber about entangled leads. Such clots may embolize to the lung
and produce severe complications and even fatality. Furthermore,
the presence of unused leads in the venous pathway and inside the
heart can cause considerable difficulty in the positioning and
attachment of new endocardial leads in or to the heart.
[0006] Removal of an inoperative lead sometimes can be accomplished
by applying traction and rotation to the outer free end of the
lead, but only if done prior to fixation of the lead tip in the
trabeculations of myocardial tissue by scar tissue formation or
large clot development. Even then, it is possible that a clot has
formed so the removal of the leads causes various sized emboli to
pass to the lungs, producing severe complications.
[0007] In cases where the lead tip has become attached by scar
tissue to the myocardial wall, removal of the lead always has
presented problems and risks. Porous lead tips that are sometimes
used may have an in-growth of scar tissue attaching them to the
myocardial wall. Sufficient traction on such leads in a removal
attempt could cause disruption of the myocardial wall prior to
release of the embedded lead tip. The tines or flanges of other
types of leads that are not tightly scarred to the myocardial wall
present similar risks. Even if screw-in tip electrodes are used,
wherein the tips theoretically can be unscrewed from the myocardial
wall, unscrewing of such tips may be prevented by a channel of scar
tissue and endothelium that surrounds the outer surface of the lead
along the venous pathway. Such "channel scar" tissue prevents
withdrawal because of tight encasement of the lead. Continual
strong pulling or twisting of the outer free end of the lead could
cause rupture of the atrial wall or the ventricular wall if there
is such tight circumferential encasement of adherent channel scar
tissue in the venous path. Such tight encasement by scar tissue in
the venous pathway and in the trabeculations of the myocardial wall
typically occurs within six months to a year of the initial
placement of the lead.
[0008] The risks of removing the lead by such traction and rotation
of the lead may be high enough so that, if it becomes imperative
that the lead be removed (as in the case of infection), many
surgeons have elected to open the patient's chest and surgically
remove the lead rather than attempt removal by applying traction
and rotation thereto.
[0009] Clearly, there is a need for an apparatus for extracting
endocardial leads from a patient's body with minimized risk to the
patient.
SUMMARY OF THE INVENTION
[0010] To address these and other drawbacks in the existing art,
the present invention comprises an apparatus for grasping a free
end of an endocardial lead and cutting the lead as near as possible
to the lead's embedded electrode. Once the lead is severed, a
majority of the lead is removed thereby, leaving just a small
distal portion of the lead within the patient.
[0011] Specifically, the present invention comprises an apparatus
having a tubular member for receiving the lead. Positioned
generally at a distal end of the tubular member is at least one
blade or cutting surface. In some embodiments, an adjustment
mechanism actuates the blade between extended and retracted
positions to engage the cutting surface with the lead to cut the
lead. Once severed, the cut portion of the lead is disposed within
the tubular member and the apparatus is removed from within the
patient.
[0012] Other aspects of the invention will be apparent to those
skilled in the art after reviewing the drawings and the detailed
description below.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The present invention will now be described, by way of
example, with reference to the accompanying drawings, in which:
[0014] FIG. 1 illustrates a perspective view of an endocardial lead
removing apparatus of a first embodiment of the present
invention;
[0015] FIG. 2A illustrates a perspective view of a distal end of an
inner tubular member of the first embodiment of the present
invention;
[0016] FIG. 2B illustrates a perspective view of a distal end of an
outer tubular member of the first embodiment of the present
invention;
[0017] FIG. 3A illustrates a perspective view of the distal end of
the inner tubular member of the first embodiment of the present
invention having an angled cutting surface;
[0018] FIG. 3B illustrates a perspective view of the distal end of
the outer tubular member of the first embodiment of the present
invention having an angled cutting surface;
[0019] FIG. 3C illustrates a first embodiment of the present
invention having a T-shaped cutting channel;
[0020] FIG. 4 illustrates a cross-sectional view along a
longitudinal axis of a tubular member of an endocardial lead
removing apparatus of another embodiment of the present
invention;
[0021] FIG. 5 illustrates a perspective view of the endocardial
lead removing apparatus of an embodiment including an insert and
adjustment mechanism;
[0022] FIGS. 6A-6C illustrate a perspective view of an endocardial
lead removing apparatus of another embodiment of the present
invention;
[0023] FIG. 7 illustrates an end view of the endocardial lead
removing apparatus of one embodiment, without limitation;
[0024] FIGS. 8A-8C illustrate a perspective view of an alternate
embodiment of the endocardial lead removing apparatus of an
embodiment having only one blade;
[0025] FIG. 9 illustrates a perspective view of an endocardial lead
removing apparatus of another embodiment of the present
invention;
[0026] FIGS. 10A-10B illustrate a perspective end view of the
endocardial lead removing apparatus of one embodiment having teeth
retracted and extended, respectively;
[0027] FIG. 11 illustrates a perspective view of an endocardial
lead removing apparatus of a fifth embodiment of the present
invention; and
[0028] FIG. 12 illustrates a perspective end view of the
endocardial lead removing apparatus of the fifth embodiment
including a blade and adjustment mechanism.
DETAILED DESCRIPTION
[0029] Referring generally to FIGS. 1-12, various embodiments of an
endocardial lead removing apparatus are generally referred to at
10.
[0030] Referring to FIG. 1, in some embodiments, the invention
comprises an apparatus 10 that includes an outer tubular member 12
and an inner tubular member 14. Each tubular member 12, 14 includes
an inner cavity 16. The inner tubular member 14 is received within
the inner cavity 16 of the outer tubular member 12. Both of the
members 12, 14 have distal ends 18 and proximal ends 20 with the
proximal ends 20 of each member 12, 14 having a handle 22. As
shown, the outer tubular member 12 has a generally shorter length
than the inner tubular member 14 and the handles 22 generally abut
at the proximal ends 20. Further, the members 12, 14 are
contemplated to be made of a metallic material such as hardened
stainless steel; however other materials, such as rigid plastic,
are also contemplated by the present invention.
[0031] Generally disposed at the distal ends 18 of the outer member
12 and the inner member 14 are first and second channels 24, 26,
respectively. As shown in FIGS. 2A-2B and 3A-3B, without
limitation, the channels 24, 26 are generally L-shaped each having
a longitudinal leg 28 and a lateral leg 30. The lateral legs 30 of
each channel 24, 26 are generally orthogonal to the longitudinal
legs 28. When assembled and having the inner tubular member 14
received in the inner cavity 16 of the outer tubular member 12, the
first and second channels 24, 26 are opposed. As such, the lateral
legs 30 of each channel 24, 26 align and extend orthogonally from
the longitudinal legs 28 in opposite directions. Further, each of
the channels 24, 26 includes at least one cutting surface 32. In
some embodiments, without limitation, the invention may also
comprise an inner tubular member 14 disposed in an outer tubular
member 12 each with a T-shaped channel that forms a double blade
with one or more cutting surfaces 32 on each member (FIG. 3C).
[0032] Referring to FIGS. 2A-2B and 3A-3B, the distal ends 18 of
the inner and outer tubular members 12, 14 are illustrated. The
channels 24, 26 are bounded by a plurality of edges 34.
Specifically, the lateral legs 30 of each channel 24, 26 are
bounded by three edges 34a, 34b and 34c. At least one of the three
edges 34a-c is the cutting surface 32 described above. As
contemplated for the illustrated embodiment, the cutting surface 32
is edge 34b. Alternatively, the present embodiment could include
multiple cutting surfaces 32 such as each of the three edges 34a-c.
Referring to FIGS. 3A-3B, the edge 34b may be generally angled to
improve cutting efficiency of the apparatus 10.
[0033] In operation, the first embodiment of apparatus 10 of FIGS.
1-3 is inserted within a patient's chest cavity, blood vessel, or
other anatomical part containing a lead (not shown) and receives a
lead 100 (shown in phantom in FIG. 1) within the inner cavity 16 of
the inner tubular member 14. Once the distal ends 18 of the
apparatus 10 are positioned as near as possible to the embedded
electrode (not shown) within the patient's body the lead 100 is
received within the channels 24, 26. Each of the tubular members
12, 14 are independently rotatable and when rotated in opposite
directions the lead 100 is captured between the cutting surfaces 32
of each channel 24, 26. Additional torque applied to the handles 22
and further rotation of the members 12, 14 cuts through the lead
100. The severed portion of the lead 100 remains within the inner
cavity 16 of the inner tubular member 14 and the apparatus 10 is
removed from the patient's body.
[0034] Another embodiment of the apparatus 10 is shown in FIGS.
4-5. The embodiment includes a tubular member 212 having a distal
end 218 and a proximal end 220. The tubular member 212 is generally
flexible and made from a polymer material. Further, the tubular
member 212 may include reinforcements such as a braid or compressed
coil (not shown) to strengthen the tubular member 212 and resist
compression during operation.
[0035] Disposed within an inner cavity 216 of the tubular member
212 is a metallic wire 236. In some embodiments, without
limitation, a filament or strong cord, optionally diamond-coated,
or other element suitable for cutting, may be substituted for the
metallic wire. The metallic wire 236 has opposite ends 238
extending from the proximal end 220 of the tubular member 212.
Optionally, the opposite ends 238 of the metallic wire 236 include
handles 222. The metallic wire 236 extends through the inner cavity
216 and outwardly at the distal end 218 thereby forming a loop 240.
It is contemplated that the metallic wire 236 is made from
stainless steel or nickel titanium and has a diameter of about
0.005 inches to about 0.030 inches; however, other materials and
diameters are also contemplated by the present invention.
[0036] Also disposed within the inner cavity 216 of the tubular
member 212 is at least one lumen 242 for receiving the metallic
wire 236. The lumen could be a second polymer lumen, even include a
lubricious sleeve (such as polytetrafluoroethelene (PTFE) or FEP).
The lumen 242 may be made from a flexible material such as nickel
titanium, although other materials are also contemplated. The lumen
242 is disposed at one side of the inner cavity 216. The lumen 242
extends the length of the tubular member 212 and when only one
lumen 242 is contemplated the opposite ends 238 of the metallic
wire 236 are both disposed therein. Alternatively, two lumen 242,
one for each opposite end 238 of the metallic wire 236, may be
positioned adjacent to each other at one side of the inner cavity
216 of the tubular member 212.
[0037] In some embodiments, the invention also comprises an
adjustment mechanism 246 (FIG. 5). The adjustment mechanism 246
moves the opposite ends 238 of the metallic wire 236 to reduce or
expand the size of the loop 240. As shown, the adjustment mechanism
246 includes a rotatable pin 248 disposed within the inner cavity
216 at one side, optionally within a catheter 242. One of the
opposite ends 238 of the metallic wire 236 is fixed to the
rotatable pin 248. The second of the opposite ends 238 is fixed to
a tension mechanism 250 such as a spring and the like. A handle 222
is disposed at a proximal end 220 to rotate the rotatable pin 248
and wind the metallic wire 236 thereabout.
[0038] In operation, the apparatus 10 of FIG. 4 includes the
metallic wire 236 extending at the distal end 218 of the tubular
member 212 to form the loop 240. The apparatus 10 is inserted
within a patient and positioned near the lead 100. The free end of
the lead 100 is received within the inner cavity 216 of the tubular
member 212 and extends outwardly at the distal end 218 and through
the loop 240. The opposite ends 238 of the metallic wire 236 are
moveable to reduce the size of the loop 240. When the metallic wire
236 is disposed in a single lumen 242 or two adjacent lumen 242, as
illustrated in FIG. 4, the opposite ends 238 are simply pulled
through the tubular member 212 and the loop 240 is reduced in size.
Accordingly the metallic wire 236 of the loop 240 slices through
the lead 100. The severed portion of the lead 100 remains within
the inner cavity 216 of the tubular member 212 and the apparatus is
removed from the patient.
[0039] Alternatively, as illustrated in FIG. 5, in some
embodiments, two separate lumens 242 are employed and the
adjustment mechanism 246 is utilized. One lumen is preferably
adjacent or nearly so. As described above, the lead 100 is received
in the inner cavity 216 and extends outwardly at the distal end 218
and through the loop 240. The adjustment mechanism 246 is actuated
by rotating the rotatable pin 248, preferably using handle 220.
Accordingly, one of the opposite ends 238 is wound around the
rotatable pin 248 and the size of the loop 240 is reduced. The lead
100 is captured between the insert 244 and the loop 240. The
cutting surface 232 of the insert 244 and the metallic wire 236 of
the loop 240 slice through the lead 100. The severed portion of the
lead 100 remains within the inner cavity 216 of the tubular member
212 and the apparatus 10 is removed from the patient.
[0040] Now referring to FIGS. 6-8, another embodiment of the
apparatus 10 of the present invention is illustrated. Again the
apparatus 10 includes a tubular member 312 having a distal end 318
and a proximal end 320. The tubular member 312 is preferably a
metal coil shaft to allow for flexibility while resisting
compression during operations. However, any material is
contemplated by the present invention.
[0041] At least one blade 352 is pivotally connected to the distal
end 318 of the tubular member 312. As seen in FIGS. 6A-6C, two
blades 352 are pivotally connected at the distal end 318 by a pivot
pin 354. Each of the blades 352 is generally arcuate to define a
cutting surface 332. Further, the blades 352 are moveable between a
retracted position (FIG. 6A) and an extended position (FIGS.
6B-6C).
[0042] As an alternate configuration, seen in FIGS. 8A-8C, the
apparatus 10 includes only one blade 352. Again, the blade 352 is
pivotally connected at the distal end 318 by the pivot pin 354. The
blade 352 is generally arcuate to define an inner cutting surface
332. The distal end 318 of the tubular member 312 is generally
angled and defines a second cutting surface 332. The blade 352 is
moveable between the retracted position (FIG. 8A) and the extended
position (FIGS. 8B-8C).
[0043] The apparatus 10 of another embodiment further includes an
adjustment mechanism 346. The adjustment mechanism 246 pivots the
blade(s) 352 between the retracted and extended positions. By way
of example, the adjustment mechanism 346 may include an outer
sheath (not shown) that receives the tubular member 312 and is
moveable longitudinally along the tubular member 312. A distal end
of the outer sheath generally aligns with the distal end 318 of the
tubular member 312 and engages the blade(s) 352. Continued
longitudinal movement of the outer sheath urges the blades(s) 352
about the pivot pin 354 to pivot from the retracted to the extended
position.
[0044] As a further example and illustrated in FIGS. 6 and 8, the
adjustment mechanism 346 includes a pull wire 356. The pull wire
356 is attached to the blade(s) 352 and extends within an inner
cavity 316 of the tubular member 312. A proximal end of the pull
wire 356 is preferably joined to a handle 322.
[0045] In operation, the embodiment of apparatus 10 of FIGS. 6-8 is
inserted within a patient's heart or other anatomical part
containing a lead and receives the lead 100 within the inner cavity
316 of the tubular member 312. Once the distal end 318 of the
apparatus 10 is positioned as near as possible to the embedded
electrode tip within the patient's body the adjustment mechanism
346 is actuated. As shown, tension is applied to the pull wire 356,
preferably at the handle 322, and the blade(s) 352 pivot about the
pivot pin 354. The lead 100 is captured between the cutting
surfaces 332 of the two blades 352 (FIGS. 6A-6C). Alternately, the
lead 100 is captured between the cutting surface 332 of the one
blade 352 and the cutting surface 332 of the distal end 318 of the
tubular member 312 (FIGS. 8A-8C). Additional tension is applied to
the pull wire 356 and the cutting surfaces 332 cut through the lead
100. The severed portion of the lead 100 remains within the inner
cavity 316 of the tubular member 312 and the apparatus 10 is
removed from the patient's body.
[0046] Referring to FIGS. 9-10, another embodiment of the apparatus
10 of the present invention is illustrated. The apparatus 10
includes a tubular member 412 having a distal end 418 and a
proximal end 420. The tubular member 412 defines a longitudinal
axis A-A and an inner cavity 416. The tubular member 412 is
generally flexible and is preferably made from a plastic or polymer
material. However, any material is contemplated by the present
invention.
[0047] At least one tooth 458 is generally positioned at the distal
end 418 of the tubular member 412 within the inner cavity 416. The
tubular member 412 includes a tubular wall 460 defining the inner
cavity 416. The tooth 458 connects to the tubular wall 460. The at
least one tooth 458 includes a plurality of edges 462 and at least
one of the edges 462 is a cutting surface 432. As illustrated, this
embodiment of the apparatus 10 comprises four teeth 458. However,
the present invention contemplates a plurality of teeth 458 or even
only one tooth 458. As shown the four teeth 458 of the illustrated
embodiment are generally triangular; however, the present invention
also contemplates asymmetrically shaped teeth 458.
[0048] The teeth 458 of this embodiment are moveable between a
retracted position and an extended position. The retracted
position, as shown in FIG. 10A, positions the teeth 458 generally
parallel to the tubular wall 460 of the tubular member 412. In
contrast, the extended position, as shown in FIG. 10B, positions
the teeth 458 generally orthogonal to the tubular wall 460 of the
tubular member 412. Accordingly, when the teeth 458 are in the
extended position the tubular member 412 has a reduced inner
diameter.
[0049] A hinge mechanism 464 connects the teeth 458 to the tubular
wall 460 of the tubular member 412. The hinge mechanism 464 adjusts
the teeth 458 between the retracted position and the extended
position to place the cutting surfaces 432 of the teeth 458 in
contact with the lead 100. Optionally, the apparatus 10 may include
an actuator (not shown) for adjusting the teeth 458 between the
positions. Otherwise, the movement of the teeth 458 between the
positions is manually actuated by a handle 422 at the proximal end
420 of the tubular member 412.
[0050] In operation, this embodiment of apparatus 10 is inserted
within a patient's heart or other anatomical part containing a lead
and positioned near the embedded electrode tip. The free end of the
lead 100 is received within the inner cavity 416 of the tubular
member 412. As the tubular member 412 is extended over the lead
100, the teeth 458 are in the retracted position and generally
parallel to the tubular wall 460. Once the distal end 418 of the
tubular member 412 is positioned as near as possible to the
embedded electrode tip, the tubular member 412 is retracted.
Extension and retraction of the tubular member 412 is facilitated
by the handle 422 at the proximal end 420. When the tubular member
412 is retracted, contact between the cutting surface 432 and the
lead 100 urges the teeth 458 to the extended position generally
orthogonal to the tubular wall 460. Accordingly, the lead 100 is
captured by the teeth 458 in the reduced diameter of the tubular
member. Continued extension and retraction of the tubular member
412 over the lead 100 moves the teeth 458 between the retracted and
extended positions. The cutting surfaces 432 repetitively contact
the lead 100 and cut through. Once severed, the cut portion of the
lead 100 remains within the inner cavity 416 of the tubular member
412 and the apparatus 10 is removed from the patient.
[0051] Referring to FIGS. 11-12, a fifth embodiment of the
apparatus 10 of the present invention is illustrated. The apparatus
10 includes a tubular member 512 defining a tubular wall 560 and a
longitudinal axis A-A. The tubular member 512 is generally flexible
and made from a plastic or polymer material; however, any material
is contemplated by the present invention. The tubular member 512
and tubular wall 560 define an inner cavity 516. The inner cavity
516 is generally offset from the longitudinal axis A-A of the
tubular member 512 in order to accommodate a blade 552 and
adjustment mechanism 546 within the tubular wall 560.
[0052] The apparatus 10 includes the blade 552 disposed within the
tubular wall 560 of the tubular member 512. The blade 552, by way
of the adjustment mechanism 546, is moveable between a retracted
position and an extended position. Further, the blade 552 includes
a generally arcuate cutting surface 532.
[0053] The adjustment mechanism 546 of the fifth embodiment is
pneumatically actuated. As seen in FIG. 12, the adjustment
mechanism 546 includes an inflatable device 566, such as a balloon
and the like. The inflatable device 566 is disposed within the
tubular wall 560 and placed adjacent the blade 552 at an end
opposite the cutting surface 532. Expansion and retraction of the
inflatable device 566 expands or retracts the cutting surface 532
of the blade 552 into the inner cavity 516 of the tubular
member.
[0054] Further, the adjustment mechanism 546 includes a guide
comprising of two projecting arms 568 and a track 570. The guide
facilitates movement of the blade 552 between the retracted and
extended positions to insert the cutting surface 532 into the inner
cavity 516. The blade 552 is adapted to receive first ends 572 of
each of the projecting arms 568. As illustrated in FIG. 12, the
blade includes a notch 574. Received within the notch 574 are the
first ends 572 of the projecting arms 568. Accordingly, the
projection arms 568 are generally parallel to the cutting surface
532 of the blade 552. The projecting arms 568 slide within the
notch 574. Second ends 576 of the projecting arms 568 are received
within the track 570. The track 570 is disposed within the tubular
wall 560 and extends circumferentially about the tubular member
512.
[0055] In operation, the fifth embodiment of apparatus 10 of FIGS.
11-12 is inserted within a patient's heart or other anatomical part
containing a lead and positioned as near as possible to the
electrode tip embedded within the body. The free end of the lead
100 is received within the inner cavity 516 of the tubular member
512. Air is supplied through a catheter (not shown) to the
inflatable device 566 or balloon. The inflatable device 566 expands
thereby urging the blade 552 from the retracted position to the
expanded position and inserting the cutting surface 532 of the
blade 552 into the inner cavity 516. Further, as the blade 552
moves from the retracted position to the expanded position the
second ends 576 of the projecting arms 568 move along the track 570
sliding within the notch 574 as appropriate, to accommodate the
varying width of the inner cavity 516. The cutting surface 532 of
the blade 552 cuts through the lead 100. Once severed, the cut
portion of the lead 100 remains within the inner cavity 516 and the
apparatus 10 is removed from the patient.
[0056] While the present invention has been particularly shown and
described with reference to the foregoing preferred and alternative
embodiments, it should be understood by those skilled in the art
that various alternatives to the embodiments of the invention
described herein may be employed in practicing the invention
without departing from the spirit and scope of the invention as
defined in the following claims. It is intended that the following
claims define the scope of the invention and that the apparatus
within the scope of these claims and their equivalents be covered
thereby. This description of the invention should be understood to
include all novel and non-obvious combinations of elements
described herein, and claims may be present in this or a later
application to any novel and non-obvious combination of these
elements. The foregoing embodiments are illustrative, and no single
feature or element is essential to all possible combination that
may be claimed in this or a later application. Where the claims
recite "a" or "a first" element of the equivalent thereof, such
claims should be understood to include incorporation of one or more
such elements, neither requiring nor excluding two or more such
elements.
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