U.S. patent number RE29,345 [Application Number 05/679,185] was granted by the patent office on 1977-08-09 for method and apparatus for non-surgical, reversible sterilization of females.
This patent grant is currently assigned to The Franklin Institute. Invention is credited to Robert A. Erb.
United States Patent |
RE29,345 |
Erb |
August 9, 1977 |
Method and apparatus for non-surgical, reversible sterilization of
females
Abstract
A method and apparatus is provided for non-surgical reversible
sterilization of females. In the method of this invention an
apparatus to which a removable tip is attached is inserted into the
uterus. The tip is aligned with the uterine end of the oviduct. A
curable elastomeric composition is injected, through an aperture in
the tip, into the oviduct in an amount sufficient to fill the
portion of the oviduct adjacent to the uterus. The elastomeric
composition is allowed to solidify and adhere to the above noted
tip. The apparatus is then removed with the tip being ejected from
the apparatus so as to remain adhered to the resulting oviduct
block. The above procedure is repeated for the opposite oviduct.
The resulting oviduct blocks prevent the passage of ovum from the
ovaries to the uterus and sperm from entering the oviduct thereby
preventing conception. The oviduct blocks if desired can be removed
non-surgically by utilizing an apparatus which grips the tip
portion of the oviduct block and extracts the entire oviduct block
from the oviduct.
Inventors: |
Erb; Robert A. (Valley Forge,
PA) |
Assignee: |
The Franklin Institute
(Philadelphia, PA)
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Family
ID: |
26989911 |
Appl.
No.: |
05/679,185 |
Filed: |
April 22, 1976 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
335816 |
Feb 26, 1973 |
03805767 |
Apr 23, 1974 |
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Current U.S.
Class: |
128/831; 128/840;
606/157; 128/887 |
Current CPC
Class: |
A61F
6/225 (20130101) |
Current International
Class: |
A61F
6/00 (20060101); A61F 6/22 (20060101); A61B
019/00 () |
Field of
Search: |
;128/1R,2R,130,33R,234-236,151,152 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
Stevenson et al., Jour. Obstet. & Gynec. of Gt. Brit., Nov.
1972, vol. 79, pp. 1028-1039. .
Thompson et al., Human Sterilization - 1971 - Charles C. Thomas,
Pub. Chapt. 30, pp. 353-359. .
Rakshit - Human Sterilization - 1971, Charles C. Thomas - Pub.
Chapt. 20, pp. 213-221..
|
Primary Examiner: Truluck; Dalton L.
Attorney, Agent or Firm: Dorfman, Herrell and Skillman
Government Interests
The invention described herein was reduced to practice in the
course of work under a grant or award from the Department of
Health, Education and Welfare.
Claims
I claim:
1. The method of forming non-surgically removable oviduct block in
a female comprising the step of
a. providing a shaped tip member having an aperture defined
therein; said tip member having a configuration such as to fit in
substantial sealing contact adjacent to the uterine end of the
oviduct of said female, and having a size larger than the lumen of
said oviduct; said tip member being formed from a given cured
elastomeric material
b. positioning said tip member within the uterine cavity of said
female adjacent to the uterine end of said oviduct with the
aperture of said tip member being in axial alignment with the lumen
of said oviduct
c. injecting through the aperture of said tip member into the lumen
of said oviduct a mixture of a fluid self curing elastomeric
material which will solidify in said oviduct and adhere to said tip
member, said elastomeric material being injected into said oviduct
in an amount sufficient to block the passage of ovum through said
oviduct to the uterine cavity
d. and thereafter allowing said uncured elastomeric material to
cure to a solidified mass while in contact with said tip member,
whereby an oviduct block is formed wherein the tip member remains
within the uterine cavity where it can be gripped by mechanical
means to remove the oviduct block non-surgically.
2. The method according to claim 1 wherein said tip member further
includes a loop member whereby said loop member can be gripped to
non-surgically remove said oviduct block.
3. The method according to claim 1 wherein said self-curing
elastomeric material is a self-curing silicone elastomer.
4. The method according to claim 1 wherein said self-curing
elastomeric material when solidified has a modulus of elasticity
substantially the same as said oviduct.
5. The apparatus for forming the oviduct block according to claim
1, said apparatus comprising: a tubular means of a length
sufficient to extend from vagina area of said female to the uterine
ends of said oviducts and having a diameter sufficiently small to
pass through the cervix of said female; said tubular means having
first and second terminal ends; said first terminal end having an
apertured tip member detachably connected thereto and also means
for releaseably holding and ejecting said tip member, said tubular
member including means for positioning said first terminal end with
said tip member thereon adjacent the uterine end of said oviduct,
and said tubular member further including means for transmission of
said self curing elastomeric material from a point adjacent to the
second terminal end to and through said aperture in said tip member
secured to the first terminal end.
6. The apparatus of claim 5 in which the first terminal end portion
is flexible.
7. The apparatus according to claim 5 in which the position of the
first terminal end is controlled by means operable from the second
terminal end.
8. The apparatus according to claim 5 wherein the means for holding
and ejecting said tip member comprises a slideable member
positioned within said tubular member whereby when a tip member is
secured at the first terminal end to said slideable member and said
slideable member is drawn through said tubular member toward the
second terminal end said tip is removed from said slideable
member.
9. The apparatus according to claim 5 wherein the dispensing means
is a syringe having a barrel and a plunger and wherein the plunger
is advanceable within the barrel by a rack and pawl drive operated
from the second terminal end. .Iadd. 10. Apparatus for forming an
oviduct block comprising: a tubular means having a length
sufficient to extend from the vagina area of a female to the
uterine end of the oviduct and having a diameter sufficiently small
to pass longitudinally through the cervix of said female; said
tubular means having first and second terminal ends; said first
terminal end having means to engage and connect a tip member
thereto, said tubular means including means therein for adjustably
displacing said first terminal end laterally relative to said
second terminal end to position said first terminal end adjacent
the uterine end of said oviduct to cause the tip member to at least
temporarily block said uterine end; said tubular means further
including fluid passage means for transmission of a plastic
material from a point adjacent to the second terminal end into said
oviduct beyond said tip member at first terminal end of said
tubular means, and means to dispense a sufficient amount of said
material to fill a predetermined length of the oviduct and to flow
into engagement with the tip member at the uterine end of said
oviduct, to form a block having an enlarged end portion exposed in
the uterine end of the oviduct. .Iaddend..Iadd. 11. The apparatus
of claim 10 in which the tubular means adjacent the first terminal
end has a flexible portion separable from the block formed by said
plastic material, said flexible portion affording displacement of
said first terminal end relative to said second terminal end.
.Iaddend..Iadd. 12. The apparatus according to claim 10 in which
the adjustable means is operable from the second terminal end.
.Iaddend. .Iadd. 13. The apparatus according to claim 10 in which
the means for dispensing said plastic material is a syringe having
a barrel and a plunger, the plunger being advanceable within the
barrel by a rack and pawl drive operated from the second terminal
end to dispense said sufficient amount. .Iaddend. .Iadd. 14.
Apparatus for forming an oviduct block comprising: a tubular means
having a length sufficient to extend from the vagina area of a
female to the uterine end of the oviduct and having a diameter
sufficiently small to pass through the cervix of said female; said
tubular means having first and second terminal ends; said first
terminal end including means for holding and releasing a tip
member, said tubular means including means for positioning said
first terminal end with said tip member thereon adjacent the
uterine end of said oviduct to at least temporarily block said
uterine end; said tubular means further including fluid passage
means for transmission of a plastic material from a point adjacent
to the second terminal end into said oviduct beyond said tip member
at first terminal end of said tubular means, and means to dispense
a sufficient amount of said material to fill a predetermined length
of the oviduct and to flow into engagement with the tip member at
the uterine end of said oviduct, to form a block having an enlarged
end portion exposed in the uterine end of the oviduct, said holding
and releasing means comprising a slidable member positioned within
said tubular means, whereby when the tip member is held at the
first terminal end by said slidable member and said slidable member
is drawn through said tubular means toward the second terminal end,
said tip member is released from said slidable member. .Iaddend.
.Iadd. 15. A non-surgically removable oviduct block for a female,
comprising: a solid body of solidified plastic material having a
transverse dimension conforming to the interior of the oviduct and
having at one end a solid molded tip portion with a configuration
adapted to fit in contact with the uterine end of the oviduct of
said female forming a single unit; said molded tip portion having a
transverse dimension larger than the interior of the oviduct to
prevent said block from migrating into the intraperitoneal cavity,
whereby said tip portion remains accessible from the uterine
cavity, said molded tip portion having means thereon which can be
gripped by mechanical means to remove the oviduct block
non-surgically; said body of plastic material having a length
providing a volume sufficient to block the passage of ovum through
said oviduct to the uterine cavity of said female. .Iaddend. .Iadd.
16. The oviduct block of claim 15 in which the plastic material
forming the oviduct block has approximately the same modulus of
elasticity as the oviduct. .Iaddend. .Iadd. 17. The oviduct block
of claim 15 in which the length of said plastic material body is at
least one third of the length of the oviduct. .Iaddend. .Iadd. 18.
The oviduct block of claim 15 in which the plastic material is a
cured elastomeric material. .Iaddend..Iadd. 19. The oviduct block
of claim 18 in which the elastomeric material is a self-curing
silicone elastomer. .Iaddend. .Iadd. 20. The oviduct block of claim
15 in which the tip portion includes a loop member comprising said
means to be gripped to non-surgically remove said oviduct block
from the oviduct. .Iaddend..Iadd. 21. The method of forming
non-surgically removable oviduct block in a female, comprising the
steps of:
a. introducing an injecting means through the cervical os into the
uterine cavity of said female;
b. providing a pre-formed tip member having an aperture therein
adjacent to the uterine end of the oviduct of said female to limit
the flow of material dispensed by the injecting means;
c. injecting from said injecting means through said aperture into
the interior of said oviduct beyond said tip member a plastic
material which will flow into engagement with said tip member, said
plastic material being injected into said oviduct in an amount
sufficient to block the passage of ovum through said oviduct to the
uterine cavity; and
d. allowing said plastic material to solidify in said oviduct in
contact with said tip member to provide a single-unit oviduct block
at least partially formed by said solidified plastic material, said
tip member providing a portion larger than the interior of the end
of said oviduct exposed in the uterine cavity, whereby the exposed
portion of the block can be gripped by mechanical means to remove
the oviduct block non-surgically. .Iaddend. .Iadd. 22. The method
of forming non-surgically removable oviduct block in a female,
comprising the steps of:
a. introducing an injecting means through the cervical os into the
uterine cavity of said female;
b. providing a seal between said injecting means and the wall of
the uterus in the marginal area circumscribing the uterine end of
the oviduct of said female to limit the flow into the cavity of
material dispensed by the injecting means;
c. injecting from said injecting means into the interior of said
oviduct beyond said seal a plastic material which will flow into
engagement with said seal, said plastic material being injected
into said oviduct in an amount sufficient to block the passage of
ovum through said oviduct to the uterine cavity; and
d. allowing said plastic material to solidify in said oviduct and
provide an oviduct block at least partially formed by said
solidified plastic material and having a tip portion larger than
the interior of the end of said oviduct exposed in the uterine
cavity, whereby the exposed portion of the block can be gripped by
mechanical means to remove the oviduct block non-surgically.
.Iaddend..Iadd. 23. The method according to claim 22 wherein said
seal is provided by a pre-formed molded tip member having an
aperture therein and the plastic material injected into the
interior of the oviduct is injected through the aperture of said
tip member. .Iaddend. .Iadd. 24. The method according to claim 22
further including the step of providing a loop member on the
exposed portion in said uterine cavity to permit removal of said
oviduct block by engaging the loop and extracting said block.
.Iaddend..Iadd. 25. The method of claim 22 in which the plastic
material injected into the oviduct has approximately the same
modulus of elasticity as the oviduct. .Iaddend..Iadd. 26. The
method of claim 22 in which the plastic material is a self-curing
elastomeric material. .Iaddend..Iadd. 27. The method of claim 26 in
which the elastomeric material fills at least one third of the
length of the oviduct. .Iaddend. .Iadd. 28. The method of forming
non-surgically removable oviduct block in a female, comprising the
steps of:
a. introducing an injecting means through the cervical os into the
uterine cavity of said female;
b. positioning the injecting means adjacent the uterine end of the
oviduct and providing a seal with the uterine wall in the marginal
area circumscribing the interior of the oviduct limiting the flow
into the uterine cavity of material dispensed by the injecting
means;
c. injecting from said injecting means into the interior of said
oviduct beyond said seal a plastic material which will flow into
engagement with said seal, said plastic material being injected
into said oviduct in an amount sufficient to block the passage of
ovum through said oviduct to the uterine cavity; and
d. allowing said plastic material to solidify in said oviduct and
provide an oviduct block at least partially formed by said
solidified plastic material, whereby the block can be gripped by
mechanical means to remove the oviduct block non-surgically.
.Iaddend..Iadd. 29. The method of claim 28 including the step of
providing a molded tip portion as an integral part of said block,
said tip having means directed toward and located in the uterine
cavity and of a shape to be gripped for removal of the block.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention is concerned with a method and apparatus for
non-surgical, reversible sterilization of females.
2. Description of the Prior Art
One of the more pressing problems which is encountered in the World
today is that of over population. The problem of over population
which has been a substantial problem for a considerable period of
time in certain highly populated areas, such as Asia and the Indian
Sub-Continent is now becoming a problem in less populated areas of
the World such as Europe and the Americas. Over population results
in such long range problems as pollution, famine and even war.
Birth control has been relied on as the principal means to control
over population. In the field of birth control the prevention of
conception is considerably more acceptable for controlling
population growth than abortion. However, the methods heretofore
suggested for contraception have had certain inherent problems
which limited the applicability and effectiveness.
The ideal contraception method should be 100 percent effective in
preventing conception; should not rely on willpower; should not
interfere with the satisfaction of sexual relationships, and should
be low in cost taking into consideration the effective life of the
contraceptive method. In addition the contraceptive method must not
have any harmful psychological side effects. An extremely important
feature of an ideal contraceptive method especially for family
planning is that it be reversible so that it will be possible to
have additional children if desired.
The most common methods of contraception which are currently
employed on a mass scale each have certain inherent deficiencies
which limit their usefulness. The use of such techniques and
devices such as rhythm, withdrawal, condoms and diaphragms and
vaginal foams all have been found to be highly unreliable. The more
recently promoted methods such as intrauterine devices and use of
contraceptive pills likewise have certain defects which limit their
effectiveness. The intrauterine devices cannot be utilized by all
females and there is some indication that they cause irritation and
discomfort and are often rejected by females. The contraceptive
pill cannot be utilized by many females due to incompatability with
their normal hormone balance. Furthermore, the use of the pill has
been found to increase the risks of certain .[.carcigenic.].
.Iadd.carcinogenic .Iaddend.conditions.
There are currently two methods in wide use which are generally
considered to be effective contraceptive methods. These are oviduct
ligation for females and vasectomy for males. In both these methods
the ducts from the reproductive organs are severed and accordingly
the contraceptive technique if properly performed and there is no
natural regeneration are 100% effective. However, both methods have
the defect that it is difficult, if not impossible, to reverse the
procedure so as to restore the normal reproductive capacity.
It has been well established by gynecologists that a primary cause
of infertility in females is blockage of the oviducts from the
ovary to the uterus. The ovum when discharged from the ovaries is
absorbed by the body and is prevented from coming in contact with
the sperm and accordingly conception does .Iadd.not .Iaddend.occur.
Females having this natural condition normally do not even realize
it exists and do not suffer any adverse side effect besides being
infertile. Having been made aware of this natural condition those
skilled in the art have suggested artificial blocking of the
oviduct to impart sterility.
It was reported by Corfman et al. in Obstetrices and Gynecology
Vol. 27 No. 6 pages 880-883 (June 1966) that various substances
could be injected transcervically into the oviducts.
Hefnawi et al. Amr. J. Obst and Gynec, Vol. 99, No. 3 pages 421-427
(Oct. 1, 1967) reported attempts to block the oviducts by the
injecting of medical grade elastomeric materials in the uncured
state into the oviducts and allowing the material to solidify in
the oviducts. The elastomeric material was thinned prior to
injection so as to have a relatively fluid mixture for injection.
The reported results obtained with rabbits was quite
unsatisfactory. The incidence of pregnancy after insertion of the
oviduct blocks was quite high. Effective sterilization was only
achieved if the plug was placed in the medial portion of the
oviduct. To remove the plug it was necessary to conduct laparotomy.
A further problem which was reported was the tendency for the plug
to migrate from the oviduct into either the uterine cavity or even
more dangerously into the peritoneal cavity.
Rakshit reported in the Calcutta Med J 65, No. 3 (Mar., 1968)
attempts to use various materials to block the oviducts to prevent
conception. It was suggested to use a plastic material of a nature
which solidifies after being mixed with a catalyst to form the
oviduct blocks. Rakshit specifically taught however that because of
high viscosity the silicone rubbers could not be injected
transvaginally and laparotomies were conducted to inject the
material directly into the uterus. The material was then allowed to
flow into the oviducts. It was suggested in this article by Rakshit
that it may be possible to introduce a plastic material
transcervically into the uterus and then to allow it to flow in the
oviducts. Using this method however the resulting oviduct blocks
would have to be removed surgically to reestablish fertility.
Rakshit further reported in Human Sterilization edited by Ralph
Rechart (1971) pages 213-221 the technique of attempting to form
oviduct blocks by inserting a cannula directly into the uterus
through the cervix and filling the uterus with a curable liquid
silicone plastic. The injected silicone plastic was allowed to flow
into the oviducts and cure in place to form the desired oviduct
blocks. The excess material was then removed from the uterus. The
reported results were not promising. On tests reported on 14 women
there were nine satisfactory blockages, three doubtful cases and
two negative cases. Further, in order to remove the oviduct blocks
it was necessary to conduct a laparotomy.
SUMMARY OF THE INVENTION
In accordance with this invention a method and apparatus is
provided to form oviduct blocks which prevent conception when in
place and can be non-surgically removed if desires. The apparatus
is inserted through the cervical os into the uterus. The tip on the
apparatus is then aligned with the uterine end of the oviduct. A
mixture of a fluid elastomeric material and a catalyst for
polymerizing the elastomeric mixture is injected through an
aperture in the tip into the oviduct. The elastomeric material is
allowed to solidify and to adhere to the tip. The tip is released
so that it remains with the injected elastomeric material to form
the oviduct block of this invention. The apparatus is then removed.
The oviduct block can be removed nonsurgically by inserting an
instrument into the uterus through the cervix which grips the tip
of the oviduct block and then withdrawing the oviduct block which
restores normal fertility.
BRIEF DESCRIPTION OF THE DRAWING
FIG. 1 is an illustration in partial cross-section of an apparatus
especially adopted for use in the method of this invention.
FIG. 2 is an illustration in partial cross-section of a uterus, the
cervix and a portion of the vagina. The uterus is illustrated with
an oviduct block insert in one of the oviduct and the terminal end
of the apparatus of FIG. 1 positioned for insertion of an oviduct
block into the opposite oviduct.
FIG. 3 is an enlarged illustration taken in partial cross-section
of the terminal end of the apparatus of FIG. 1.
FIG. 4 is an illustration in cross-section of the terminal end of
the apparatus of FIG. 3 shown with fluid uncured elastomeric
material shown in the internal feed tube.
FIG. 5 is an illustration shown in cross-section showing the
separation of the tip from the apparatus of FIG. 1.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
In the method of this invention an oviduct block is formed in situ
in the oviduct. The oviduct block is most preferable formed from a
medical inert plastic which has approximately the same modulus of
elasticity as the oviduct. The selection of material having the
proper modulus of elasticity appears to both prevent expulsion of
the oviduct block and substantially eliminates any physical
discomfort. The materials which have been found most useful in the
method of this invention are the commercially available medical
grade silicone elastomers. The uncured silicone elastomer in the
fluid state is blended with a catalyst for solidifying the
elastomer and a dilution fluid to control the viscosity during
injection and also to control the modulus of elasticity of the
cured solidified material. It is preferable to also include a
radiopaque material in the mixture to facilitate the placement of
the oviduct block and to facilitate removal of the oviduct block if
.[.desires.]. .Iadd.desired.Iaddend..
A tip 10 is molded from an inert plastic material to which the
injected elastomeric material will adhere on solidification. In
this regard it should be noted that silicone-rubber is ideally
suited for this purpose when a silicone elastomer is used for
formation of the oviduct block.
As shown in the drawing the portion of the tip 10 which will be in
contact with uterine end of the oviduct 12 has a spherical
configuration. The tip 10 has an aperture 14 which extends
throughout the entire length of the tip .[.14.]. .Iadd.10.Iaddend..
In addition the tip as illustrated has a series of annular piston
rings 16 molded into the interior .[.portion.]. surface of the
aperture 14. The tip 10 further includes a loop 18 which is
preferably a thread of a material which is inert in uterine fluids,
such as nylon.
The apparatus 20 shown in FIG. 1 is specifically designed for use
in the method of this invention. The apparatus 20 includes a
tubular extension 22, a dispensing apparatus 24, and a control
handle 26 for both operating the dispensing means and positioning
the tip 10 on the end of the tubular extension 22.
The tubular extension 22 has a rigid section which is adjacent to
the control handle 26. The opposite terminal end portion 28 on
which the tip 10 is secured is flexible. One end of each control
wire 30, 32 is attached to the end portion of the flexible section
28. The control wires 30, 32 are connected at their opposite ends
to a pair of separately controlled drums 34 (only one drum is
shown) mounted on the control .[.hand.]. .Iadd.handle .Iaddend.26.
By adjustment of the drums 34 to either to collect or release the
wires 30, 32 the position of the tip 10 can be adjusted and bent in
a curved configuration shown in FIG. 2.
At the flexible terminal end 28 a metal connector 36 is provided
which has annular piston .[.ring.]. .Iadd.rings .Iaddend.38 which
.[.mates.]. .Iadd.mate .Iaddend.with the piston rings 16 on the tip
10. The metal connector 36 further has defined in it a constricted
area having a sharp cut off portion 40.
A tube 42 extends from the dispensing means 24, through the tubular
extension 22 to the aperture 14 in the tip 10.
The dispensing means 24 consists of a mixing syringe 44 in which
the plunger 46 is adapted to provide mixing of a fluid elastermeric
material, a catalyst and other additive as may be required. The
syringe 44 is mounted on top of the control handle 26 with the
plunger 46 in contact with a rack 48 and a pivotal mounted pawl 50.
The pawl 50 is connected to a trigger 52. Squeezing the trigger 52
causes the plunger 46 to be advanced within the syringe .[.46.].
.Iadd.44 .Iaddend.and material within the syringe 44 to be
dispensed through the tube 42 to the tip 10.
In the method of this invention the tip 10 is inserted over the end
of the flexible portion 28 of the tubular extension. The tip 10
being premolded of a silicone rubber is somewhat elastic and
deforms somewhat until the piston ring 16 of the tip of 10 engages
and locks with the mating piston rings 38.
The tubular extension .[.20.]. .Iadd.22 .Iaddend.with tip 10
installed is inserted into the vagina 54, through the cervical os
56 into the uterine cavity 58. Then, preferably using
.[.flouroscopic.]. .Iadd.fluoroscopic .Iaddend.techniques, the tip
10 is aligned with the uterine end of one of the oviducts 12. It
should be noted that because of the shape of the uterine cavity 58
the tip can be guided blindly in the proper position. The relative
position of the flexible end 28 is controlled by adjustment of the
drums 34.
Once the tip 10 is in position the fluid mixture of the elastomer,
catalyst and other additives are injected through the tube 42 to
the tip 10 by operation of the trigger 52 as noted above. The
uncured fluid elastomeric mixture 60 flows through the aperture 14
in the tip 10 and then into the oviduct 12. A sufficient amount of
the mixture is injected to fill approximately one third or more of
the length of the oviduct 12. Some of the material will flow back
around the tip 10 so that the surface of the tip 10 will conform to
the shape of the uterine end of the oviduct 12 as shown in the tip
10 as modified 62 which is shown in FIG. 5.
The injected elastomeric material 60 is allowed to cure and
solidify. The cured material will adhere to the tip 10 to make an
essential single unit.
Once the elastomeric material has cured, the tube .[.40.]. .Iadd.42
.Iaddend.and the terminal end .[.36.]. .Iadd.28 .Iaddend.are
withdrawn within the tubular extension 22. The edge 40 cuts the
cured material which remains in the tube 42 from the cured material
in the aperture 14 of the tip 10. Continued withdrawal of the
terminal end .[.36.]. .Iadd.28 .Iaddend.results in the tip 10 being
stripped from the terminal end as shown in phantom in FIG. 5.
The procedure noted above is repeated for the opposite oviduct to
complete the sterilization procedure.
The solidified oviduct blocks each has a configuration which
conforms to the interior of the oviduct in which it is cast, thus
effectively preventing conception.
.Iadd.The shaped tip member has an aperture defined therein and a
configuration such as to fit in substantial sealing contact
adjacent to the uterine end of the oviduct of the female. It has a
size larger than the lumen of said oviduct and is positioned within
the uterine cavity of said female adjacent to the uterine end of
said oviduct with the aperture of said tip member being in axial
alignment with the lumen of said oviduct, whereby the tip member
remains within the uterine cavity where it can be gripped by
mechanical means to remove the oviduct block nonsurgically.
.Iaddend.
The oviduct block can remain in place until it is desired to remove
it. The use of a material having approximately the same modulus of
elasticity as the oviducts assists in maintaining the oviduct
blocks 64 in position. The natural convolution of the oviduct
likewise results in stabilization of the oviduct blocks 64. The tip
10 serves a most important function of preventing the oviduct block
64 from migrating into the intraperitoneal cavity, a problem that
was a serious and relatively common problem with other similar
prior art .[.technique.]. .Iadd.techniques.Iaddend. .
As noted above the oviduct block is inserted nonsurgically. The
method is relatively simple to learn by those skilled in the
medical art. The time required is likewise quite short with a
skilled person being able to block both oviducts in about 15 to 30
minutes.
As noted above the oviduct block can be removed nonsurgically if
desired. An instrument of the type shown in FIG. 1 is used for this
purpose. The tip 10 is replaced with a hooked member which is
adapted to engage the loop 18. Once the loop 18 is engaged the
oviduct block 64 is withdrawn. It is also possible to use a pronged
member to grip the tip and then pull out the oviduct block.
Both the insertion and removal of the oviduct block 64 are
relatively painless. However a local anesthetic can be used if
desired.
The effectivenes of the contraception method of this invention was
found to be excellent. On rabbit tests it was found that the method
is 100% effective if the oviduct blocks are properly placed. In
further rabbit tests it was found that after the oviduct blocks
were removed that fertility was restored. There was no indication
of expulsion of the oviduct blocks either in the uterine cavity or
in the intraperitoneal cavity. Histologic examination and scanning
election microscopic examination have not indicated that there is
any adverse reaction to the tissue of the oviducts.
The apparatus of this invention has been described in .Iadd.the
.Iaddend.preferred embodiment. It should be appreciated that
.[.the.]. various modifications can be made to the apparatus
without departing from the scope of this invention. For example,
the control handle 26 has been provided to enable a simple one
handed operation of the apparatus. .[.If.]. .Iadd.It .Iaddend.is
possible, however, to simply use control wires which are operated
by the fingers of the hand rather than the drums. Further, the
dispensing apparatus consisting of the trigger 52, rack 48 and pawl
50, could likewise be removed and the syringe operated manually.
Furthermore, the configuration of the tip 10 can be modified to a
different shape such as a conical configuration .[.of.]. .Iadd.or
.Iaddend.other suitable shapes and still be satisfactory for use in
this invention. These and other modifications which would be
obvious to those skilled in the art are included within the scope
of the subjoined claims.
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