U.S. patent application number 10/846047 was filed with the patent office on 2004-10-28 for contraceptive transcervical fallopian tube occlusion devices and their delivery.
This patent application is currently assigned to CONCEPTUS, INC.. Invention is credited to Nikolchev, Julian, Thurmond, Amy, Ton, Dai.
Application Number | 20040211429 10/846047 |
Document ID | / |
Family ID | 23884894 |
Filed Date | 2004-10-28 |
United States Patent
Application |
20040211429 |
Kind Code |
A1 |
Nikolchev, Julian ; et
al. |
October 28, 2004 |
Contraceptive transcervical fallopian tube occlusion devices and
their delivery
Abstract
The invention provides intrafallopian devices and non-surgical
methods for their placement to prevent conception. The efficacy of
the device is enhanced by forming the structure at least in part
from copper or a copper alloy. The device is anchored within the
fallopian tube by imposing a secondary shape on a resilient
structure, the secondary shape having a larger cross-section than
the fallopian tube. The resilient structure is restrained in a
straight configuration and transcervically inserted within the
fallopian tube, where it is released. The resilient structure is
then restrained by the walls of the fallopian tube, imposing
anchoring forces as it tries to resume the secondary shape.
Inventors: |
Nikolchev, Julian; (Portola
Valley, CA) ; Ton, Dai; (San Jose, CA) ;
Thurmond, Amy; (Portland, OR) |
Correspondence
Address: |
James C. Scheller, Jr.
BLAKELY, SOKOLOFF, TAYLOR & ZAFMAN LLP
12400 Wilshire Boulevard
Seventh Floor
Los Angeles
CA
90025-1026
US
|
Assignee: |
CONCEPTUS, INC.
San Carlos
CA
|
Family ID: |
23884894 |
Appl. No.: |
10/846047 |
Filed: |
May 14, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10846047 |
May 14, 2004 |
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09591874 |
Jun 12, 2000 |
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09591874 |
Jun 12, 2000 |
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08474779 |
Jun 7, 1995 |
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6176240 |
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Current U.S.
Class: |
128/831 ;
128/830 |
Current CPC
Class: |
A61B 17/12022 20130101;
A61B 17/12145 20130101; A61F 6/225 20130101; A61B 2017/1205
20130101; A61F 6/22 20130101; A61F 6/18 20130101; A61B 17/12099
20130101; A61B 17/1215 20130101 |
Class at
Publication: |
128/831 ;
128/830 |
International
Class: |
A61F 006/06 |
Claims
1-31. (canceled)
32. A method for sterilizing a female patient using an elongated
instrument assembly having a distal end, said method comprising:
inserting the distal end of the elongated instrument assembly
transcervically into the female patient, the distal end of the
elongated instrument having a detachable body which includes a
non-biodegradable material; applying energy from the elongated
instrument to a surrounding tissue of a fallopian tube of said
female patient; detaching the detachable body from the distal end
of the elongated instrument assembly; and removing a remaining
portion of the elongated instrument assembly from the female
patient, wherein a scar formation in a region of the surrounding
tissue permanently attaches to the detachable body.
33. The method of claim 32 wherein the energy comprises electrical
energy and wherein the scar formation encapsulates the detachable
body.
34. A method as in claim 32 wherein said detachable body is
resilient and imposes an anchoring force against said surrounding
tissue.
35. A method as in claim 32 wherein said elongated instrument
assembly comprises a conductive interface which is coupled to a
surface assembly which is coupled to said elongated instrument
assembly.
36. A method as in claim 32 wherein said elongated instrument
assembly comprises an elongate body and a shaft which is disposed
within said elongate body.
37. A method as in claim 32 wherein said applying precedes said
detaching of said detachable body.
38. A method as in claim 32 wherein said detachable body has a
first configuration prior to said detaching and a second
configuration after said detaching.
39. A method as in claim 38 wherein said first configuration has an
outer diameter which is less than an inner diameter of said
fallopian tube.
40. A method as in claim 32 wherein said detachable body comprises
a polymer material.
41. A method comprising: inserting a catheter having an
electrically conductive surface assembly mounted on a distal end of
the catheter through the vagina and the cervical canal of a patient
and into the uterus of the patient; advancing a detachable
assembly, which is coupled to the catheter, into a fallopian tube
of the patient, said detachable assembly including a
non-biodegradable material; applying electrical energy to the
electrically conductive surface assembly; detaching the catheter
from the detachable assembly, wherein a permanent scar formation in
the fallopian tube encapsulates the detachable assembly.
42. A method as in claim 41 wherein said detachable assembly is
resilient and imposes an anchoring force against the fallopian
tube.
43. A method as in claim 41 wherein said catheter comprises a
conductive interface which is coupled to said electrically
conductive surface assembly.
44. A method as in claim 41 wherein said catheter comprises an
elongate body and a shaft which is disposed within said elongate
body.
45. A method as in claim 41 wherein said applying precedes said
detaching of said detachable assembly.
46. A method as in claim 41 wherein said detachable assembly has a
first configuration prior to said detaching and a second
configuration after said detaching.
47. A method as in claim 46 wherein said first configuration has an
outer diameter which is less than an inner diameter of said
fallopian tube.
48. A method as in claim 41 wherein said detachable assembly
comprises a polymer material.
49. A method as in claim 44 wherein said catheter further comprises
a lumen through which said shaft is slidable.
50. A method as in claim 41 wherein said applying said electrical
energy is through a shaft within a lumen of said catheter.
51. An intrafallopian delivery system for transcervical
introduction of a device, the delivery system comprising: a first
portion having an elongate body and a shaft for delivering energy;
a second portion detachably coupled to said elongate body, said
second portion including a non-biodegradable material and being
sized to fit within a fallopian tube and being detachable from said
elongate body to remain permanently within said fallopian tube and
wherein said energy causes a scar formation, in said fallopian
tube, which attaches to said second portion.
52. A delivery system as in claim 51 wherein said energy comprises
electrical energy and wherein said shaft delivers electrical
current.
53. A delivery system as in claim 51 wherein said second portion is
resilient and imposes an anchoring force against said fallopian
tube.
54. A delivery system as in claim 51 wherein said shaft is disposed
within a lumen of said elongate body.
55. A delivery system as in claim 51 wherein said energy is
delivered before said second portion is detached from said elongate
body.
56. A delivery system as in claim 51 wherein said second portion
has a first configuration prior to being detached and a second
configuration after being detached.
57. A delivery system as in claim 56 wherein said first
configuration has an outer diameter which is less than an inner
diameter of said fallopian tube.
58. A delivery system as in claim 51 wherein said second portion
comprises a polymer material.
59. A delivery system as in claim 51 further comprising an
introducer through which said elongate body is inserted.
60. A delivery system as in claim 51 wherein said second portion
has a surface which attaches to said scar formation.
61. An intrafallopian catheter system for transcervical
introduction of an intrafallopian device, said catheter system
comprising: an elongate body having a shaft for delivering
electrical energy; a detachable body which is detachably coupled to
said elongate body, said detachable body including a
non-biodegradable material and being sized to fit within a
fallopian tube and being detachable from said elongate body to
remain permanently within said fallopian tube and wherein said
electrical energy causes a scar formation, in said fallopian tube,
which encapsulates said detachable body.
62. A catheter system as in claim 61 wherein said detachable body
is resilient and imposes an anchoring force against said fallopian
tube.
63. A catheter system as in claim 61 wherein said shaft is disposed
within a lumen of said elongate body.
64. A catheter system as in claim 61 wherein said electrical energy
is delivered before said detachable body is detached from said
elongate body.
65. A catheter system as in claim 61 wherein said detachable body
has a first configuration prior to being detached and a second
configuration after being detached.
66. A catheter system as in claim 65 wherein said first
configuration has an outer diameter which is less than an inner
diameter of said fallopian tube.
67. A catheter system as in claim 61 wherein said detachable body
comprises a polymer material.
68. A catheter system as in claim 61 further comprising an
introducer through which said elongate body is inserted.
69. A catheter system as in claim 61 wherein said detachable body
has a surface which attaches to said scar formation.
70. A method for sterilizing a female patient, said method
comprising: delivering a body transcervically into the female
patient, said body including a non-biodegradable material;
delivering energy to a surrounding tissue of a fallopian tube of
said female patient; wherein a scar formation in a region of the
surrounding tissue permanently attaches to the body.
71. The method of claim 70 wherein the energy comprises electrical
energy and wherein the scar formation encapsulates said body.
72. A method as in claim 70 wherein said body is resilient and
imposes an anchoring force against said surrounding tissue.
73. A method as in claim 70 wherein an elongated instrument
assembly delivers said body and is detachably coupled to said
body.
74. A method as in claim 70 wherein said body is not expelled from
said fallopian tube.
75. A method as in claim 70 wherein said body comprises a polymer
material.
76. A method as in claim 70 wherein said body has a first
configuration prior to said delivering and a second configuration
after said delivering.
77. A method as in claim 76 wherein said first configuration has an
outer diameter which is less than an inner diameter of said
fallopian tube.
78. A method as in claim 70 wherein said body comprises an open
outer wall which allows tissue ingrowth into said body.
79. An intrafallopian delivery system for transcervical
introduction of a device, the delivery system comprising: a first
portion having an elongate body; a second portion detachably
coupled to said elongate body, said second portion including a
non-biodegradable material and being sized to fit within a
fallopian tube in an area exposed to energy to damage tissue in
said fallopian tube and being detachable from said elongate body to
remain permanently within said fallopian tube and wherein said
energy causes a scar formation, in said fallopian tube, which
attaches to said second portion.
80. A delivery system as in claim 79 wherein said energy comprises
electrical energy.
81. A delivery system as in claim 79 wherein said second portion is
resilient and imposes an anchoring force against said fallopian
tube.
82. A delivery system as in claim 79 wherein said energy is
delivered before said second portion is detached from said elongate
body.
83. A delivery system as in claim 79 wherein said second portion
has a first configuration prior to being detached and a second
configuration after being detached.
84. A delivery system as in claim 83 wherein said first
configuration has an outer diameter which is less than an inner
diameter of said fallopian tube.
85. A delivery system as in claim 79 wherein said second portion
comprises a polymer material.
86. A method for sterilizing a female patient, said method
comprising: delivering a body transcervically into the female
patient, said body having an open outer wall which allows tissue
ingrowth into said body; delivering energy to a surrounding tissue
of a fallopian tube of said female patient; wherein a scar
formation in a region of the surrounding tissue permanently
attaches to said body.
87. The method of claim 86 wherein the energy comprises electrical
energy and wherein the scar formation encapsulates said body.
88. A method as in claim 86 wherein said body is resilient and
imposes an anchoring force against said surrounding tissue.
89. A method as in claim 86 wherein an elongated instrument
assembly delivers said body and is detachably coupled to said
body.
90. A method as in claim 86 wherein said body is not expelled from
said fallopian tube.
91. A method as in claim 86 wherein said body comprises a polymer
material.
92. A method as in claim 86 wherein said body has a first
configuration prior to said delivering and a second configuration
after said delivering.
93. A method as in claim 92 wherein said first configuration has an
outer diameter which is less than an inner diameter of said
fallopian tube.
94. An intrafallopian delivery system for transcervical
introduction of a device, the delivery system comprising: a first
portion having an elongate body; a second portion detachably
coupled to said elongate body, said second portion having an open
outer wall which allows tissue ingrowth into said second portion
and being sized to fit within a fallopian tube in an area exposed
to energy to damage tissue in said fallopian tube and being
detachable from said elongate body to remain permanently within
said fallopian tube and wherein said energy causes a scar
formation, in said fallopian tube, which attaches to said second
portion.
95. A delivery system as in claim 94 wherein said energy comprises
electrical energy.
96. A delivery system as in claim 94 wherein said second portion is
resilient and imposes an anchoring force against said fallopian
tube.
97. A delivery system as in claim 94 wherein said energy is
delivered before said second portion is detached from said elongate
body.
98. A delivery system as in claim 94 wherein said second portion
has a first configuration prior to being detached and a second
configuration after being detached.
99. A delivery system as in claim 98 wherein said first
configuration has an outer diameter which is less than an inner
diameter of said fallopian tube.
100. A delivery system as in claim 94 wherein said second portion
comprises a polymer material.
101. A delivery system as in claim 94 further comprising an
introducer through which said elongate body is inserted.
102. A delivery system as in claim 94 wherein said second portion
has a surface which attaches to said scar formation.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates generally to contraception,
and more particularly to intrafallopian contraceptive devices and
nonsurgical methods for their delivery.
[0003] Worldwide demand exists for safe, effective methods of both
contraception and permanent sterilization. Although a variety of
contraception and sterilization methods are available, all of the
existing methods have limitations and disadvantages. Thus, the need
for additional safe, low cost, reliable methods of contraception
and permanent sterilization, both in developed and less developed
countries, is widely recognized.
[0004] Many presently available contraception methods require
significant user involvement, and user non-compliance results in
quite high rates of failure. While the theoretical effectiveness of
existing contraceptives, including barrier methods and hormonal
therapies, is well established, overcoming user noncompliance to
improve overall efficacy has proven difficult.
[0005] One form of contraception which is less susceptible to user
noncompliance is the intrauterine device (IUD). IUDs have been
found to have higher rates of reliability, and are effective for a
longer period of time, than most other commercially available
contraceptives. Unfortunately, IUDs are also associated with
serious infectious complications. For this reason, the use of IUDs
within the United States has decreased dramatically. Additionally,
IUDs are subject to unplanned expulsion, and must be removed due to
excessive pain or bleeding in a percentage of cases, further
reducing the acceptance of the IUD as a contraceptive method.
Interestingly, the efficacy of copper IUDs appears to be higher
than that of non-metallic IUDs. The reason for this has not been
fully explained.
[0006] Commercially available options for permanent sterilization
include fallopian tube ligation and vasectomy. These methods are
surgical, are difficult to reverse, and are not available to many
people in the world. It is common knowledge that fertilization
occurs in the fallopian tubes where the sperm and ovum meet. Tubal
ligation avoids this by complete occlusion of the fallopian
tubes.
[0007] It has previously been proposed to reversibly occlude the
fallopian tubes, for example, by in vitro formation of an
elastomeric plug, or otherwise anchoring a device on either side of
the narrowest region of fallopian tube, called the "isthmus." Such
fallopian tube occlusion methods appear promising; however, an
unacceptably high percentage of the non-surgical devices proposed
to date have become dislodged during previous studies. Even where
non-surgical intrafallopian devices have remained in place, they
have been found to be only moderately effective at preventing
conception.
[0008] For these reasons, it would be desirable to provide
effective, reliable intrafallopian devices for contraception and
sterilization. It would be particularly desirable to provide highly
effective intrafallopian devices which did not require surgery for
placement. It would be especially desirable if such devices and
methods allowed easy placement of the device, but were less
susceptible to being dislodged than previously proposed
non-surgical intrafallopian devices.
[0009] 2. Description of the Related Art
[0010] The experimental use of a stainless steel intrafallopian
device is described in Transcatheter Tubal Sterilization in
Rabbits, Penny L. Ross, RT 29 "Investigative Radiology", pp.
570-573 (1994). The experimental use of an electrolytically pure
copper wire as a surgical contraceptive intrafallopian device in
rats was described in "Antifertility Effect of an Intrafallopian
Tubal Copper Device", D. N. Gupta, 14 Indian Journal of
Experimental Biology, pp. 316-319 (May 1976).
[0011] U.K. Patent Application Pub. No. 2,211,095 describes a
uterine screw plug for blocking the fallopian tube. European Patent
Application Pub. No. 0,010,812 describes a device for placement in
the oviducts having enlargements at either end for anchoring the
device. The same device appears to be described in Netherlands
Patent No. 7,810,696.
[0012] The use of tubal occlusion devices is described in
"Hysteroscopic Oviduct Blocking With Formed-in-Place Silicone
Rubber Plugs", Robert A. Erb, Ph.D., et al., The Journal of
Reproductive Medicine, pp. 65-68 (August 1979). A formed-in-place
elastomeric tubal occlusion device is described in U.S. Pat. No.
3,805,767, issued to Erb. U.S. Pat. No. 5,065,751, issued to Wolf,
describes a method and apparatus for reversibly occluding a
biological tube. U.S. Pat. No. 4,612,924, issued to Cimber,
describes an intrauterine contraceptive device which seals the
mouths of the fallopian tubes.
[0013] German Patent No. 28 03 685, issued to Brundin, describes a
device for plugging a body duct with a device which swells when in
contact with a body fluid.
[0014] Alternative contraceptive devices are disclosed in copending
U.S. patent application Ser. No.______ (attorney docket no.
16355-25), the full disclosure of which is herein incorporated by
reference.
SUMMARY OF THE INVENTION
[0015] The present invention provides intrafallopian devices and
methods for their placement to prevent conception. The
intrafallopian devices of the present invention are transcervically
delivered, resiliently anchored structures which are formed at
least in part from copper to provide long term contraception, or
alternatively permanent sterilization, without the need for
surgical procedures or the increased bleeding, pain, and risks of
infection associated with intrauterine devices (IUDs).
[0016] The use of copper in the intrafallopian device of the
present invention improves its efficacy as a contraceptive method.
Devices formed from plastically deformable materials, however, are
less readily restrained in the fallopian tube. Apparently, the
large variation in the actual shape and dimensions of fallopian
tubes does not provide reliable anchoring for a pre-formed
deformable intrafallopian device. The intrafallopian device of the
present invention therefore comprises a resilient structure,
usually a metallic coil, which includes a copper alloy, a copper
plating, or copper fibers, ideally comprising an alloy including at
least 75% copper. The coil material typically includes beryllium,
zinc, stainless steel, platinum, a shape memory alloy such as
Nitinol.TM., or the like. Preferably, the coil is composed of an
alloy of beryllium and copper. Although the present device will
generally result in occlusion, it need not completely occlude the
fallopian tube to prevent the meeting of the sperm and ovum.
Instead, the presence of the copper on the resilient structure is
sufficient to provide effective contraception.
[0017] Conveniently, the present invention further comprises
non-surgical placement of such intrafallopian devices by
transcervical introduction. The resilient structure is restrainable
in a straight configuration, e.g., by inserting the device within a
catheter, greatly facilitating and reducing the risks of
introduction. Thus, the cost and dangers associated with existing
surgical contraceptive and sterilization procedures are
avoided.
[0018] In a first aspect, a contraceptive intrafallopian device
according to the present invention comprises a resilient structure
having a proximal end and a distal end. The resilient structure
comprises copper, and is biased to form at least one bend near the
proximal end of the primary coil. Similarly, the resilient
structure is also biased to form at least one bend near its distal
end. These proximal and distal bends define an isthmus-traversing
region therebetween. Preferably, the isthmus-traversing region also
includes at least one bend, thereby helping to anchor the coil
within the fallopian tube.
[0019] Generally, the resilient structure of the present
intrafallopian device will be formed as a primary coil. To help
restrain the coil within the fallopian tube, fibers are attached to
some embodiments of the coil, the fibers optionally comprising a
polyester material such as Rayons.TM., Dacron.TM., or the like.
Alternatively, copper fibers may be used to increase the exposed
copper surface area, the copper fibers generally having a diameter
on the order of 0.001 inches.
[0020] The bends of the present intrafallopian device are generally
formed as a secondary shape imposed on a primary coil. The primary
coil is most easily formed as a straight cylindrical coil. The
secondary shape will be imposed on the primary coil by bending,
optionally heat treating the primary coil while bent. The
individual bends may take a wide variety of forms, including
sinusoidal curves, the individual loops of a continuous secondary
coil, or the like. However, the secondary shape generally defines
an overall width which is larger than the fallopian tube, so that
the tubal wall restrains the resilient structure when it is
released.
[0021] Preferably, each of the bends of the present intrafallopian
device forms a loop in the primary coil when in a relaxed state.
Ideally, the loops are separated by straight sections of coil. The
alternating of loops with straight sections of coil forms a large
diameter "flower coil," which provides a large relaxed overall
width, and also features bends of tight radius, both of which
promote retention. Conveniently, the primary coil generally has a
diameter less than that of the fallopian tube, and can be
restrained in a straight configuration for placement within the
fallopian tube, typically by inserting the primary coil within a
delivery catheter.
[0022] In another aspect, a contraceptive intrafallopian device
according to the present invention comprises a resilient primary
coil having a primary coil diameter. The primary coil comprises
copper, and forms a secondary shape when in a relaxed state. The
secondary shape defines a plurality of bends and an overall width
which is larger than the primary coil diameter. Thus the primary
coil can be easily anchored in a fallopian tube which is smaller in
diameter than the secondary shape. Preferably, the present device
reacts with a force sufficient to prevent axial movement of the
device within the fallopian tube when restrained in a lumen having
a diameter in the range between 0.5 mm and 3 mm. The actual
anchoring force will depend on the shape of the coil and the
modulus of elasticity of the material used.
[0023] In yet another aspect, a intrafallopian contraceptive
delivery system according to the present invention comprises an
elongate body in which the resilient primary coil described above
is slidably disposed. A shaft is also slidably disposed within the
elongate body and is located proximally of the primary coil. The
distal end of the shaft includes a coil interface surface, while
the elongate body restrains the primary coil in a straight
configuration.
[0024] Preferably, a bend in the isthmus-traversing region of the
present intrafallopian device, together with the proximal and
distal anchor bends, restrains the resilient structure within the
isthmus of the fallopian tube. The distal anchor is inserted into
the ampulla, distal of the isthmus, while the proximal anchor is
located in the ostium, proximal of the isthmus. Unintended movement
of the device is further avoided by locating the isthmus-traversing
region within the isthmus to resiliently impose anchoring forces
against the tubal wall.
[0025] In a still further aspect, an intrafallopian contraceptive
method according to the principles of the present invention
comprises restraining a resilient structure in a straight
configuration and transcervically inserting the resilient structure
into a fallopian tube. The resilient structure is affixed within
the isthmus by releasing a bent isthmus-traversing region. The bend
of the isthmus-traversing region exerts a force against the wall of
the fallopian tube, anchoring the device within the isthmus.
Preferably, a distal anchor on the resilient structure is released
distally of the isthmus, and a proximal anchor is released
proximally of the isthmus, the distal and proximal anchors
generally formed from bends in the resilient structure. Optionally,
an electric current is applied through the resilient structure to
the fallopian tube, thereby effecting permanent sterilization.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] FIG. 1 illustrates a first embodiment of a contraceptive
intrafallopian device according to the present invention having a
single distal anchor loop, a single proximal anchor loop, and an
isthmus-traversing region having a single loop for anchoring the
device within the fallopian tube.
[0027] FIG. 2 illustrates an alternative embodiment of a
contraceptive intrafallopian device according to the present
invention having a plurality of loops which may act as proximal,
distal, or lumen anchors.
[0028] FIG. 3 illustrates the distal portion of a delivery catheter
for placement of a contraceptive intrafallopian device according to
the present invention.
[0029] FIG. 4 illustrates the contraceptive intrafallopian device
of FIG. 1 partially released from the delivery catheter of FIG.
3.
[0030] FIGS. 5 and 6 illustrate a contraceptive method using an
intrafallopian device according to the principles of the present
invention.
DETAILED DESCRIPTION OF THE SPECIFIC EMBODIMENT
[0031] The present invention encompasses a contraceptive
intrafallopian device which can alternatively be used as both a
permanent and a reversible means of contraception. The present
contraceptive methods and devices minimize the danger of non-use
which has limited the efficacy of prior art contraceptive
techniques. Moreover, the location of the present devices within
the fallopian tubes provides a reduced risk of the infectious
complications, increased bleeding, and pelvic pain associated with
intrauterine devices (IUDs). Furthermore, the location and the
novel shape of the present intrafallopian device provides
significant advantages over IUDs, which have been found to be
susceptible to unplanned expulsion and removal due to excessive
pain and bleeding. The present invention takes advantage of the
increase in effectiveness associated with copper IUDs, providing a
resilient structure including copper which may be transcervically
positioned without the need for surgery.
[0032] Although the present contraceptive method may be included
within a group of contraceptive techniques generally referred to as
fallopian tube occlusion methods, the present invention does not
necessarily rely solely on blocking the fallopian tube to prevent
fertilization. Instead, contraception is apparently provided by
disrupting of ovum transport, the process of fertilization, and/or
cleavage of the ovum. While the effect that copper has on these
processes is not fully understood, it does appear that copper
intrafallopian devices offer potentially significant increases in
effectiveness over intrafallopian devices formed of other
materials. Optionally, the present invention further encompasses
devices which promote tissue growth within the tube to induce tubal
occlusion, further inhibiting conception.
[0033] The present invention is anchored within the isthmus of the
fallopian tube, overcoming the unintended expulsion of the device
and the resulting failure of the contraceptive method. Such
intrafallopian device expulsion has been the single greatest factor
limiting the efficacy of easily positioned intrafallopian
contraceptive techniques.
[0034] The present intrafallopian devices are generally elongate
resilient structures pre-formed into secondary shapes. These
secondary shapes will bias the resilient structure so as to provide
strong forces against the lumen wall of the fallopian tube.
Clearly, the secondary shape must have a larger outer diameter than
the inner diameter of the fallopian tube.
[0035] Conveniently, the present resilient structures are
insertable into a catheter, the catheter wall restraining the
resilient structure in a straight configuration. As the resilient
structure has an outer diameter when in the straight configuration
which is less than the inner diameter of the fallopian tube, the
catheter containing the present intrafallopian device is easily
transcervically introduced. Moreover, the device is readily removed
by snaring the resilient structure near the proximal end and
pulling proximally on the resilient structure, thereby
straightening the resilient structure and allowing it to be
withdrawn without injuring the fallopian tube. Alternatively, an
electrical current is applied to the device after it is at least
partially releasing the fallopian tube, providing permanent
sterilization.
[0036] Referring now to FIG. 1, a first embodiment of the present
contraceptive intrafallopian device 10 is formed from a resilient
primary coil 12. Primary coil 12 is most easily originally formed
as a straight cylindrical coil or spring, preferably having an
outer diameter in the range from 0.2 mm to 5 mm, and having a
length in the range from 20 mm to 150 mm. Ideally, primary coil 12
has an outer diameter in the range from 0.4 mm to 2 mm and a length
in the range from 30 mm to 70 mm. The straight primary coil may
then be bent into a variety of secondary shapes.
[0037] The primary coil 12 of intrafallopian device 10 includes a
proximal end 14 and a distal end 16. Between these ends, three
loops 20 are formed, each having an inner diameter 22. Located
between loops 20 are straight sections 24, which increase the
overall cross-section of the intrafallopian device to an overall
width 26. Preferably, inner diameter 22 is in the range from 2 mm
to 10 mm, while overall width 26 is at least 6 mm, ideally being in
the range from 8 mm to 40 mm. Distal and proximal ends 14, 16 each
include an atraumatic endcap 18 to prevent injury to the fallopian
tube.
[0038] Preferably, primary coil 12 is formed from a beryllium
copper alloy wire. Beryllium copper provides the resilience
necessary to avoid expulsion of the device, and also provides the
increased effectiveness of a copper contraceptive intrafallopian
device. Alternatively, primary coil 12 is formed from a resilient
metal, such as stainless steel, platinum, a shape memory alloy, or
the like. If such materials are used, primary coil 12 is preferably
plated with copper or a copper alloy or otherwise has copper
attached.
[0039] To further reduce the possibility of expulsion of
intrafallopian device 10, fibers are optionally carried on primary
coil 12. The fibers may be short individual fibers, or may
alternatively be wound into primary coil 12. Preferably, the fibers
comprise copper, thereby increasing the total copper surface area.
Such copper fibers are preferably bonded to primary coil 12 with
solder, brazing, a polymeric adhesive, or the like. Alternatively,
polyester fibers such as Dacron.TM., Rayon.TM., or the like, are
bonded to the surface of primary coil 12 using a polymeric
adhesive. The polyester fibers promote increased tissue growth
around the coil, thus further reducing the possibility of expulsion
of the device from the fallopian tube.
[0040] A secondary shape has been superimposed on the primary coil
to form intrafallopian device 10, the secondary shape comprising
loops 20 separated by straight sections 24. This secondary shape is
herein referred to as a "flower coil." The flower coil shape is
particularly advantageous in that outer diameter 26 is
substantially larger than the primary coil diameter, while the
individual loops 20 have relatively small inner diameters 22 which
will maintain the largest possible anchoring force against the
fallopian tube. Minimizing inner diameter 22 also ensures that
anchoring force is applied within the fallopian tube, despite the
curvature of the fallopian tube.
[0041] Referring now to FIG. 2, an alternative embodiment of the
present contraceptive intrafallopian device 30 includes additional
loops to ensure anchoring of the device within the fallopian tube.
Alternative embodiment 30 is formed from an elongate primary coil
32 having a proximal end 34 and a distal end (not shown). Elongate
primary coil 32 has an outer diameter 36 which is smaller than the
isthmus of the fallopian tube, allowing the straightened
intrafallopian device to be inserted easily. Elongate primary coil
32 has been bent to form a secondary shape including a larger
number of loops 38 than the embodiment of FIG. 1. Loops 38 have an
outer diameter 40 which is larger than the inner diameter of the
fallopian tube, preventing loops 38 from assuming their relaxed
shape. Loops 38 are again separated by straight sections 42 of
elongate primary coil 32, increasing the overall intrafallopian
device diameter 44.
[0042] In both embodiments of the present intrafallopian device 10,
30, at least one loop adjacent to the proximal end is disposed
proximally of the narrowest portion of the fallopian tube, referred
to as the isthmus. Similarly, at least one loop of the
intrafallopian device is disposed distally of the isthmus. These
proximal and distal loops act as anchors, helping to prevent
proximal or distal movement of the intrafallopian device. In the
embodiment of FIG. 2, at least one loop is also disposed adjacent
to the isthmus of the fallopian tube, further helping to prevent
unintentional expulsion.
[0043] Alternative intrafallopian device 30 may be positioned with
multiple loops acting as proximal or distal anchors, or may
alternatively have all but the proximal and distal anchor loops
disposed along the fallopian tube to act as anchors within the
lumen of that body. Advantageously, the embodiment of FIG. 2 is
therefore less sensitive to variations in total fallopian tube
length.
[0044] Referring now to FIG. 3, a delivery catheter for the present
intrafallopian device comprises an elongate body 52 and a shaft 54.
Elongate body 52 includes a lumen 56 in which shaft 54 is disposed,
shaft 54 being slidable in the axial direction. Shaft 54 includes a
core 58 having a tapered distal end 60, allowing the device to
navigate through tortuous bends while retaining the column strength
required to advance the device. Core 58 extends proximally through
elongate body 52, and is capable of transferring compressive forces
through the elongate body. Core 58 is typically formed from
stainless steel, a stainless alloy, or the like. Disposed over
distal end 60 of core 58 is pusher cap 62. Pusher cap 62 provides a
low friction, deformable end piece having a distal coil interface
surface 64. Pusher cap 62 is preferably formed of a low friction
polymer such as PTFE, or the like.
[0045] Intrafallopian delivery catheter 50 receives the present
intrafallopian device within the distal end of lumen 56 of elongate
body 52. Lumen 56 has an inner diameter which is slightly larger
than outer diameter 36 of the primary coil. The present
intrafallopian device is therefore straightened to a straight
configuration as it is loaded proximally into the distal end of
lumen 56. Elongate body 52 is sufficiently strong to restrain the
primary coil in the straight configuration, but must remain
sufficiently flexible to allow maneuvering within the body lumen.
Elongate body 52 is preferably formed from an inelastic, flexible
material such as polyurethane, PET, or the like.
[0046] Referring now to FIG. 4, intrafallopian device 10 is
released from delivery catheter 50 within the fallopian tube by
holding shaft 54 while proximally withdrawing elongate body 52.
Distal coil interface surface 64 engages the proximal end 14 of
primary coil 12. Initially, primary coil 12 is restrained in a
straight configuration by elongate body 52. As elongate body 52 is
withdrawn, primary coil 12 is released. When primary coil 12 is
unrestrained it forms loop 20; when released within the fallopian
tube it will generally be restrained by the tubal wall in a
configuration between straight and the relaxed secondary shape.
Preferably, the first loop released will form a distal anchor bend
66. Subsequent loops will bias primary coil 12 against the
fallopian tube, and form a proximal anchor bend, in that order.
[0047] Use of the present contraceptive intrafallopian device will
be described with reference to FIGS. 5 and 6. A uterine introducer
canula 70 is inserted transcervically through a uterus 72 to the
region of an ostium 74. Elongate body 52 is then extended distally
from canula 70 into a fallopian tube 77, preferably guided under
fluoroscopy. Alternatively, a hysteroscope may be used in place of
canula 70. Elongate body 52 is maneuvered using a guide wire 78
past an isthmus 80.
[0048] After elongate body 52 extends past isthmus 80, guide wire
78 is removed. An intrafallopian device according to the present
invention is inserted in the proximal end of elongate body 52, the
intrafallopian device being restrained in a straight configuration
by the elongate body. The device is advanced distally using shaft
54, the shaft and elongate body forming delivery catheter 50 (FIG.
3). Delivery catheter 50 is axially positioned so that at least one
loop of the intrafallopian device is within a target region 84
adjacent to isthmus 80. Preferably, at least one loop is distal of
target region 84, and at least one loop is proximal of target
region 84 to form the distal and proximal anchor bends of the
implanted intrafallopian device.
[0049] Once delivery catheter 50 is properly positioned, elongate
body 52 may be axially withdrawn. Shaft 54 axially restrains the
intrafallopian device at the target location during withdrawal of
elongate body 52, as described regarding FIG. 4. As the distal end
of the primary coil is released, the distal loop forms a distal
anchor bend 90. Similarly, the proximal loop forms a proximal
anchor bend 92. Intermediate loops are restrained within the narrow
target region 84, exerting substantial anchoring forces against the
walls of the fallopian tube. As seen in FIG. 6, the loops need not
assume their relaxed form to provide effective distal or proximal
anchors.
[0050] The present invention further encompasses permanent
sterilization by passing a current through the shaft to the
intrafallopian device after elongate body 52 has been partially
withdrawn, but before the intrafallopian device is fully released.
Fallopian tube tissue in contact with the intrafallopian device is
dessechated, and thus attached to the present intrafallopian
device. This action also causes permanent tubal damage, leading to
the formation of scar tissue which encapsulates the intrafallopian
device and causes permanent occlusion of the tubal lumen. Clearly,
the resilient member/shaft interface must be conductive to allow
the present non-surgical method of permanent sterilization.
[0051] In conclusion, the present invention provides a
contraceptive intrafallopian device which may be positioned without
surgery. While the above is a complete description of the preferred
embodiments of the invention, various alternatives, modifications,
and equivalents may be used. For example, a wide variety of
secondary shapes, including open loops, continuous bends,
sinusoidal curves, or the like, may be imposed on the primary coil.
Therefore, the above description should not be taken as limiting
the scope of the invention, which is defined instead solely by the
appended claims.
* * * * *