U.S. patent application number 10/734876 was filed with the patent office on 2004-07-01 for non-rotating breast implant.
This patent application is currently assigned to Howard T. Bellin. Invention is credited to Bellin, Howard T., Campbell, Ruairidh W., Kredovski, Kenneth C..
Application Number | 20040127985 10/734876 |
Document ID | / |
Family ID | 29270854 |
Filed Date | 2004-07-01 |
United States Patent
Application |
20040127985 |
Kind Code |
A1 |
Bellin, Howard T. ; et
al. |
July 1, 2004 |
Non-rotating breast implant
Abstract
A non-rotating anatomical-shaped breast implant having a front
side with a smooth surface and a rear side with a textured surface.
A smooth surface ripples or wrinkles little, if at all. Rippling or
wrinkling of the implant may undesirably produce a visible or
palpable waviness on the skin of the breast. A smooth surface is
more likely to produce the look and feel of a natural breast. A
rear side with a textured surface is desirable because tissue
growth of the body, after the implant has been implanted, engages
the textured surface to anchor the implant in place such that the
front side with the smooth surface remains matched with the front
side of the body and such that the anatomical-shaped breast implant
with its tear drop shaped fullness remains at a natural position
within the breast. The disclosure further includes a method for
minimizing the rotation of an implant within the body and a method
for making an implant envelope that has different thicknesses.
Inventors: |
Bellin, Howard T.; (New
York, NY) ; Kredovski, Kenneth C.; (Roseville,
MN) ; Campbell, Ruairidh W.; (Salt Lake City,
UT) |
Correspondence
Address: |
HAUGEN LAW FIRM
SUITE 1130 - TCF TOWER
121 SOUTH EIGHTH STREET
MINNEAPOLIS
MN
55402
|
Assignee: |
Howard T. Bellin
|
Family ID: |
29270854 |
Appl. No.: |
10/734876 |
Filed: |
December 12, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10734876 |
Dec 12, 2003 |
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09452656 |
Dec 1, 1999 |
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6692527 |
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Current U.S.
Class: |
623/8 ;
264/232 |
Current CPC
Class: |
B29C 37/0053 20130101;
B29C 41/14 20130101; A61F 2/12 20130101; A61F 2/0077 20130101; B29C
2791/001 20130101; B29L 2031/7532 20130101 |
Class at
Publication: |
623/008 ;
264/232 |
International
Class: |
A61F 002/12 |
Claims
What is claimed is:
1. A breast implant for being implanted within a body, wherein the
body includes front, rear, right and left sides, wherein the breast
implant comprises: a) an envelope having at least two sides,
wherein the envelope is fillable with fluid to provide a
three-dimensional shape to the envelope; b) wherein one of the
sides of the envelope comprises a relatively smooth surface; and c)
wherein the other of the sides of the envelope comprises a
relatively rough surface, wherein tissue growth by the body engages
the relatively rough surface after the envelope has been implanted
such that the envelope is restrained from rotating and such that
the relatively smooth surface may be oriented as desired within the
body.
2. The breast implant according to claim 1, wherein one of the
sides of the envelope is thicker than the other of the sides of the
envelope, wherein the thicker side of the envelope comprises the
relatively rough surface, and wherein the thinner side of the
envelope comprises said relatively smooth surface.
3. The breast implant according to claim 1, wherein one of the
sides of the envelope has been cured once, wherein the other side
of the envelope has been cured twice, and wherein the side that has
been cured once comprises said relatively smooth surface.
4. The breast implant according to claim 1, wherein the envelope is
anatomically-shaped in the form of a breast and comprises front,
rear, right and left sides, wherein the front, rear, right and left
sides of the envelope are oriented toward the front, rear, right
and left sides of the body, wherein the rear side of the
anatomically-shaped envelope comprises the relatively rough
surface, wherein the front side of the envelope comprises the
relatively smooth surface, and wherein each of the right and left
sides comprises the relatively smooth surface.
5. The breast implant according to claim 1, wherein the envelope
has a total surface area, wherein the relatively smooth surface
tuns over about 50% of the total surface area, and wherein the
relatively rough surface runs over about 50% of the total surface
area.
6. The breast implant according to claim 1, wherein the envelope
includes an opening through which a mandrel had been removed,
wherein the envelope is sealed with a patch engaged over the
opening and to the envelope, and wherein the patch includes an
exterior surface which includes the relatively rough surface.
7. A non-rotating anatomical-shaped breast implant for being
implanted within a body, wherein the body includes front, rear,
right and left sides, with the non-rotating anatomical-shaped
breast implant comprising: a) an envelope formed in the anatomical
shape of a breast, wherein the envelope comprises front, rear,
right and left sides; b) wherein the envelope is fillable with fill
material; c) wherein the front side of the envelope comprises a
relatively smooth surface; and d) wherein the rear side of the
envelope comprises a relatively rough surface, wherein tissue
growth by the body engages the relatively rough surface after the
implant has been implanted such that the envelope is restrained
from rotating and such that the front, rear, right and left sides
of the envelope remain respectively oriented toward the front,
rear, right and left sides of the body.
8. The non-rotating anatomical-shaped breast implant according to
claim 7, wherein the envelope includes fill material prior to the
envelope being implanted.
9. A breast implant comprising: a) an envelope having an anterior
side, posterior side, superior pole, inferior pole and a nipple
position, with the nipple position being on the anterior side near
the inferior pole; b) wherein the anterior side has a first
thickness; c) wherein the posterior side has a second thickness;
and d) wherein the first thickness of the anterior side is less
than the second thickness of the posterior side.
10. The breast implant of claim 9 wherein the posterior side
comprises a textured exterior surface portion.
11. The breast implant of claim 9 wherein the anterior side
comprises a smooth exterior surface portion.
12. The breast implant of claim 9 wherein the anterior side
comprises a relatively smooth exterior surface portion and wherein
the posterior side comprises a relatively rough exterior surface
portion.
13. The breast implant of claim 9 wherein the posterior side has
been cured twice and the anterior side has been once cured.
14. The breast implant of claim 9 wherein the envelope is an
anatomical-shaped breast envelope.
15. A method for minimizing rotation of a breast implant within a
body, comprising the steps of: a) selecting a breast implant; b)
forming a relatively rough surface on an exterior portion of the
breast implant and forming a relatively smooth surface on another
exterior portion of the breast implant; c) implanting the breast
implant within the body so as to orient the relatively smooth
surface in a desired direction; then d) permitting tissue growth to
engage the relatively rough surface so as to anchor the breast
implant in place, thereby minimizing rotation of the breast implant
and holding the relatively smooth surface in the desired
direction.
16. The method according to claim 15, wherein the step of forming
the relatively rough surface comprises the step of forming a
relatively rough surface over about 5% to about 50% of a total
surface area of the breast implant.
17. The method according to claim 15, wherein the step of selecting
a breast implant comprises the step of selecting an
anatomical-shaped breast implant, wherein the anatomical-shaped
breast implant comprises front, rear, right and left sides, wherein
the front side of the anatomical-shaped breast implant comprises
the relatively smooth surface, wherein the right side of the
anatomical-shaped breast implant comprises the relatively smooth
surface, wherein the left side of the anatomical-shaped breast
implant comprises the relatively smooth surface, and wherein the
rear side of the anatomical-shaped breast implant comprises the
relatively rough surface.
18. A method of making an envelope for a breast implant, comprising
the steps of: a) selecting a mandrel; b) selecting a dispersion
into which the mandrel is dipped; c) fully submerging the mandrel
in the dispersion such that an envelope is formed, withdrawing the
mandrel from the dispersion and thereby picking up a first envelope
layer on the mandrel, and permitting the first envelope layer to at
least partially stabilize; and d) partially submerging the mandrel
in the dispersion such that a portion of the mandrel remains
exposed to the atmosphere, withdrawing the mandrel from the
dispersion and thereby picking up a second envelope layer on the
mandrel and permitting the second envelope layer to at least
partially stabilize, whereby an envelope coating of a first
thickness is disposed over one portion of the mandrel and whereby
an envelope coating of a second thickness is disposed over another
portion of the mandrel.
19. The method of claim 18 wherein the step of fully submerging the
mandrel occurs prior to the step of partially submerging the
mandrel.
20. The method of claim 18 and further comprising: e) curing the
envelope between the steps of fully submerging the mandrel and
partially submerging the mandrel; and f) curing the envelope after
the step of partially submerging the mandrel.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates generally to implants for the
body and particularly to implants that have features that minimize
or prevent rotation of an implant in a body. More specifically, the
present invention is a breast implant that has an anatomical shape
that gives a more natural look to the augmented breast, but cannot
rotate because it has a texturing on the back that anchors it, yet
is smooth on the surface to minimize rippling.
[0002] The preferred shape for an implant used for cosmetic breast
augmentation is the so-called "anatomical shape" that is also
referred to as "tear drop." This shape has more of the substance
filling the silicone elastomer shell in the inferior pole of the
implant and less in the superior pole, thus mimicking the natural
shape of the breast. For a given volume, round shaped implants have
too much substance in the upper pole that can make the breast look
artificial. The anatomical implant looks much more natural.
[0003] A problem with anatomical implants is that if the outer
surface of the implant is smooth, the implant can rotate. When an
implant is surgically placed beneath the breast or beneath the
chest muscle, the body recognizes that it is a foreign object and
walls it off with tissue that is referred to as a "capsule." A
smooth-walled implant creates a smooth capsule that can allow the
implant to slip and slide within it. When a smooth-walled
anatomical-shaped breast implant rotates, as it often does, there
is more fullness laterally or medially instead of inferiorally as
intended. This creates an unacceptable deformity. Thus far the only
solution to this problem has been the use of "textured" implants
which have a rough surface. They produce a capsule that is
reciprocally rough. The "male-female" relationship of the implant
and capsule holds the implant in place and prevents its
rotation.
[0004] Textured implants have a very distinct disadvantage,
however. The problem is that textured implants have a tendency to
ripple (i.e. produce a folding, wrinkling or waviness on the
surface of the implant). Rippling creates an extremely
unsatisfactory appearance. Causes of or factors contributing to
rippling may be 1) that textured implants are cured twice, while
smooth walled implants are cured once, 2) that the textured implant
is formed with an additional coating of the silicone elastomer,
leading to a thicker wall that is less able to support itself and
thus may fold, and/or 3) the texture itself (peaks and valleys in
the surface of the implant) may produce a variety of non-linear
scores or fold lines along which the wall of the implant folds or
ripples.
[0005] Rippling--visible or palpable waviness on the implant
surface--is one of the major problems with breast implants. This
folding of the implant can often be felt or seen and can be
extremely obtrusive. Therefore, to solve the problem of implant
rotation with texturing the entire implant as is presently done,
one must compound the problem of severe, unacceptable rippling.
[0006] The present invention provides a solution to the problem.
The present invention is an implant that is textured on its
posterior surface, but smooth on its anterior surface. The textured
posterior surface causes a reciprocal textured capsule, but only
behind the implant. This interlocking with the capsule keeps the
implant from rotating. However, the textured area is only on the
back of the implant; therefore, any rippling will not be visible or
palpable. The anterior surface will remain smooth--and minimize any
unsatisfactory rippling.
[0007] Preferred fill materials for the non-rotating
anatomical-shaped breast implant include saline and viscous fill
materials. Among viscous fill materials, silicone gel, soy oil, and
hydrogels are preferred, with hydrogels being most preferred.
SUMMARY OF THE INVENTION
[0008] A feature of the present invention is a non-rotating breast
implant.
[0009] Another feature of the present invention is a non-rotating
anatomical-shaped breast implant.
[0010] Another feature of the present invention is an implant
having a first surface portion that engages tissue in the body to
anchor with little or no rotation the implant in the body and a
second surface portion that has a desirable characteristic when
oriented in a particular direction.
[0011] Another feature of the present invention is an implant
having a textured surface portion that engages tissue growth in the
body so as to anchor with little or no rotation the implant in the
body and a second surface portion that is smooth.
[0012] Another feature of the present invention is a non-rotating
anatomical-shaped breast implant with a posterior surface and an
anterior surface where the posterior surface comprises a texture to
anchor the implant in the body and where the anterior surface
comprises a smooth face to minimize wrinkling.
[0013] Another feature of the present invention is a non-rotating
breast implant having a first side with a relatively rough surface
or surface portion to interlock with body tissue to anchor the
implant and having a second side with a relatively smooth surface
or surface portion that forms little or no wrinkles and that
therefore may be oriented close to the skin to provide a natural
appearance.
[0014] Another feature of the present invention is a method for
minimizing or preventing rotation of an implant in a body so as to
permanently fix the orientation of a desirable characteristic of
the implant.
[0015] Another feature of the present invention is a method for
minimizing or preventing rotation in a body of an anatomical-shaped
implant so as to permanently fix the anterior orientation of the
front side of the anatomical-shaped implant.
[0016] Another feature of the present invention is a method of
making an envelope for an implant, where the method includes the
separate steps of 1) fully submerging and 2) partially submerging a
mandrel in a dispersion. The steps may occur in any sequence and be
repeated.
[0017] The method includes selecting, preferably, an
anatomical-shaped mandrel. Then the mandrel is dipped four times in
a dispersion of a silicone elastomer and solvent (such as xylene).
After each of the dips, the solvent is permitted to evaporate or
partially evaporate so as to permit the just-coated layer to at
least partially stabilize. After the fourth layer of silicone
elastomer (or other envelope forming material) has stabilized, the
envelope (still on the mandrel) is cured. The cured envelope, still
on the mandrel, is then partially dipped into the dispersion, i.e.,
partially submerged to the level or over the portion of the
envelope to which the texturing is to be applied. This layer (over
a portion of the envelope) is then permitted to stabilize (but is
not fully dried). Then granulated solid particles, such as salt
particles (sodium chloride for example), are applied over (such as
by being sprayed) the portion of the envelope that has the extra
layer of now stabilized but not fully dried silicone elastomer.
This portion of the envelope is the portion that is not perceptible
(visibly or by touch) when the implant is implanted into the body.
Preferably, such portion of the implant is the posterior side of
the implant. Then the envelope is cured (vulcanized). After being
cured, the envelope (still on the mandrel) is soaked in a solvent
(such as water) to dissolve or wash off the solid granules, thereby
leaving the textured surface. The envelope is then removed from the
mandrel, patched and fitted with a valve for the fill material.
[0018] Another feature of the present invention is a breast implant
having a first thickness at the nipple position and a second
thickness on the posterior side.
[0019] An advantage of the present invention is that
anatomical-shaped breast implants are held in position, with their
superior poles correctly oriented in the superior position without
slippage or spin off in the medial or lateral directions.
[0020] Another advantage of the present invention is that the
anterior side of the breast implant takes on a more natural
appearance and feel. Since the implant is anchored in place by
tissue engaging the textured posterior side of the implant, the
anterior side of the implant need not be textured and therefore may
be made of a thinner envelope wall having a smooth surface.
Thinner, smooth, once-cured envelope walls have less of a tendency
to wrinkle or ripple than do thicker, textured, twice-cured walls.
A wrinkle or ripple may be seen and/or felt through the skin of the
natural breast.
BRIEF DESCRIPTION OF THE DRAWINGS
[0021] FIG. 1A shows the front side (or anterior side or face) of
an anatomical-shaped breast implant.
[0022] FIG. 1B shows the rear side (or posterior side or face) of
the anatomical-shaped breast implant of FIG. 1A.
[0023] FIG. 1C shows the right side (medial or lateral side
dependent upon which breast) of the breast implant of FIG. 1A.
[0024] FIG. 1D shows the left side (medial or lateral side
dependent upon which breast) of the breast implant of FIG. 1A.
[0025] FIG. 2A shows the front side (or anterior side or face) of a
round-shaped breast implant.
[0026] FIG. 2B shows the rear side (or posterior side or face) of
the round-shaped breast implant of FIG. 2A.
[0027] FIG. 2C shows the right side (medial or lateral side
dependent upon which breast) of the breast implant of FIG. 2A.
[0028] FIG. 2D shows the left side (medial or lateral side
dependent upon which breast) of the breast implant of FIG. 2A.
[0029] FIG. 3A shows a cross section of the implant of FIG. 1A to
show the relatively thin wall of the anterior side of the implant
and the relatively thick wall of the posterior side of the implant,
and further shows fill material in the implant.
[0030] FIG. 3B shows a cross section of the implant of FIG. 2A to
show the relatively thin wall of the anterior side of the implant
and the relatively thick wall of the posterior side of the implant,
and further shows fill material in the implant.
[0031] FIG. 4A shows a side view of a mandrel for the
anatomical-shaped implant of FIG. 6A, and further shows a dipping
rod engagable with the rear side of the mandrel.
[0032] FIG. 4B shows a bottom view of the mandrel and, dipping rod
of FIG. 4A.
[0033] FIG. 5A shows a side view of a mandrel for the round shaped
implant of FIGS. 2A-D.
[0034] FIG. 5B shows a bottom view of the mandrel of FIG. 5A.
[0035] FIG. 6A shows a front or anterior view of an
anatomical-shaped breast implant formed using the mandrel of FIGS.
4A and 4B.
[0036] FIG. 6B shows a rear or posterior view of the
anatomical-shaped implant of FIGS. 1A-D having only a portion of
its surface textured.
[0037] FIG. 7A shows a side view of an inflatable anatomical shaped
implant having a textured posterior surface.
[0038] FIG. 7B shows a side view of an inflatable round shaped
implant having a textured posterior surface.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0039] As shown in FIGS. 1A-D and 3A, an anatomical-shaped breast
implant is designated in general by reference number 10. The
implant 10 includes an envelope 12 and fill material 14 sealed in
the envelope 12. The envelope 12 further includes a posterior
(rear) side or face 16 that includes a textured or relatively rough
surface 18 and an anterior (front) side or face 20 that is smooth
or relatively smooth compared to the relatively rough surface 18.
The envelope 12 further includes a right side 22 (shown in FIG. 1C)
and a left side 24 (shown in FIG. 1D). Depending upon the breast
into which the implant 10 is implanted, the right side 22 may be
the medial or lateral side of the implant 10 and the left side 24
may be the medial or lateral side of the implant 10. The implant 10
further includes a superior (upper) pole 26 and an inferior (lower)
pole 28. The anterior (front) side 20 of the envelope 12 has a
smooth surface 30, relatively thin wall 32 and is cured once
(though subject twice to curing temperatures). Most (over about
90%) of the right side 22 of the envelope 12 and most (over about
90%) of the left side 24 of the envelope 12 has a smooth surface 30
and a relatively thin wall portion 32 that is cured once (though is
subject twice to curing temperatures). Further, the smooth surface
30 and the relatively thin wall portion 32 extend about a portion
of each of the superior (upper) pole 26 and inferior (lower) pole
28. The posterior (rear) side 16 is formed by a relatively thick
wall 34 of the envelope 12 that is textured and that is cured
twice.
[0040] While it is preferable that an anatomical-shaped breast
implant includes the features of the present invention, it should
be noted that the features of the present invention may be used in
an alternate embodiment of the invention, specifically a round
shaped implant 36 shown in FIGS. 2A-D and 3B. The reference numbers
of the anatomical-shaped implant 10 are noted on the round shaped
implant 36 as prime reference numbers. In other words, the round
shaped implant 36 includes an envelope 12' and fill material 14'
sealed in the envelope 12'. The envelope 12' further includes a
posterior (rear) side or face 16' that includes a textured surface
18' and an anterior (front) side or face 20' that is smooth. The
envelope 12' further includes a right side 22' (shown in FIG. 2C)
and a left side 24' (shown in FIG. 2D). Depending upon the breast
into which the implant 36 is implanted, the right side 22' may be
the medial or lateral side of the implant 36 and the left side 24'
may be the medial or lateral side of the implant 36. The implant 36
further includes a superior (upper) pole 26' and an inferior
(lower) pole 28'. The anterior (front) side 20' of the envelope 12'
has a smooth surface 30', relatively thin wall 32' and is cured
once (though subject twice to curing temperatures). One-half of the
right side 22' of the envelope 12' and one-half of the left side
24' of the envelope 12' has a smooth surface 30' and a relatively
thin wall portion 32' that is cured once (though subject twice to
curing temperatures). Further, the smooth surface 30' and the
relatively thin wall portion 32' extend about a portion of each of
the superior (upper) pole 26' and inferior (lower) pole 28'. The
posterior (rear) side 16' is formed by a relatively thick wall 34'
of the envelope 12' that is textured and cured twice. As further
shown in FIGS. 2A-D and unlike with the anatomical-shaped implant
10 of FIGS. 1A-D, one-half of the right side 22' has the textured
surface 18' and one-half of the left side 24' has the textured
surface 18'. Further, one-half of the surface about each of the
poles 26' and 28' is the textured surface 18' and the other
one-half of the pole surface is the smooth surface 30.
[0041] The envelope 12 is preferably formed of a material that is
biocompatible, flexible, resilient and is substantially impermeable
to the transport of water vapor. Rubber, such as a silicone
elastomer, is a preferred material. The envelope 12 may also
include a polymeric or copolymeric water vapor barrier layer that
is extremely impermeable to the transport of water vapor and that
has greater water vapor impermeability than a rubber such as a
silicone elastomer. As to extremely impermeable water vapor barrier
layers for implants, the following U.S. Patent is hereby
incorporated by reference in its entirety: U.S. Pat. No. 5,630,844
issued May 20, 1997 and entitled Biocompatible Hydrophobic Laminate
With Thermoplastic Elastomer Layer.
[0042] The present breast envelope is formed by dipping a mandrel
into a silicone rubber dispersion. A dispersion may contain a
silicone elastomer and a solvent (such as xylene). The mandrel is
completely submerged and then raised out of the dispersion with a
thin coating of the dispersion adhering to the mandrel. It should
be noted that the first layer (formed by the first dip) is
relatively thin since the dispersion flows readily off the smooth
surface of the mandrel. The solvent is then caused to evaporate,
such as with heat and/or by having air blown over the drying
mandrels, and then the same mandrel having a layer of partially
dried or at least partially stabilized silicone elastomer is dipped
again (and allowed to at least partially stabilize) and again (and
allowed to at least partially stabilize) until the desired
thickness is obtained. In other words, after each of the first
three dips, the envelope is ready to be dipped again when the
partially stabilized just-coated layer has a certain tackiness,
i.e. may leave a clear definition of a fingerprint without the
finger picking up much if any of the dispersion (about 15 minutes
after being dipped). After the fourth dip, the envelope of four
layers is cured (still on the mandrel) at about 270.degree. F. for
about 90 minutes. Then the cured envelope of four layers is cooled
to room temperature and inspected for waviness, bubbles and foreign
material. The thickness of the final cured envelope is about
{fraction (12/1000)} (0.012) inches thick to about {fraction
(16/1000)} (0.016) inches thick.
[0043] As to making a breast envelope, the following U.S. Patents
are hereby incorporated by reference in their entireties: U.S. Pat.
No. 5,674,285 issued Oct. 7, 1997 and entitled Mammary Implant
Having Shell With Unitary Rough-Textured Outer Layer and U.S. Pat.
No. 5,630,844 issued May 20, 1997 and entitled Biocompatible
Hydrophobic Laminate With Thermoplastic Elastomer Layer.
[0044] As to making the envelope of the present invention with a
relatively thin wall (such as thin wall 32) and a relatively thick
wall (such as thick wall 34), please see FIGS. 4A and 4B. Here a
generally U-shaped dipping rod 38 extends into the posterior side
40 of a mandrel 42. Mandrel 42 includes an anterior side 44.
Mandrel 42 may be used to make the anatomical-shaped implant 70 of
FIG. 6A. U-shaped dipping rod 38 includes a proximal end 47 (that
may engage a handle for being manually dipped or that may engage an
automatic dipping apparatus) and a distal end 49 that runs into the
mandrel 42. Dipping rod 38 has a cross section that is square or
diamond-shaped and runs into a square or diamond-shaped hole in the
posterior side 40 of the mandrel 42 to minimize unintended spinning
of the mandrel 42 relative to the dipping rod 38. With the U-shaped
dipping rod 38, the posterior side 40 only of the mandrel 42 is
dipped to level L into the dispersion (of a silicone elastomer and
solvent) to the exclusion of anterior side 44 of the mandrel 42,
further to the exclusion of over about 75% of a right side 46 (i.e.
lateral or medial side depending upon the breast into which the
implant is implanted) and further to the exclusion of over about
75% of a left side 48 (i.e. lateral or medial side depending upon
the breast into which the implant is implanted) of the mandrel 42.
Such a partial dip may be the first dip in a dipping process to
form an envelope of the present invention, such as envelope 12.
Preferably, such a partial dip is the last dip in the dipping
process. Still further if desired, such a partial dip may be one of
the "in-between" dips. Also, such a partial dip may not be limited
to one partial dip. There may be two or more of such partial dips
where only the posterior side 40 is dipped into the dispersion.
After each partial dip or after each full dip, the solvent is
permitted to evaporate and the mandrel 42 is again dipped into the
dispersion until the anterior wall (such as wall 32) is the desired
thickness and the posterior wall (such as wall 34) is the desired
thickness.
[0045] Envelope 12' is formed in an identical manner, except that
the mandrel 50 of FIG. 5A is used. Mandrel 50 produces the round
shaped implant 36 of FIGS. 2A-D. Mandrel 50 includes a posterior
side 52, an anterior side 54, a right side 56 (i.e. lateral or
medial side depending upon the breast into which the implant is
implanted), and a left side 58 (i.e. lateral or medial side
depending upon the breast into which the implant is implanted)
corresponding to the posterior side 16', anterior side 20', right
side 22', and left side 24' of implant 36. Mandrel 50 is filly
submerged four times, then cured, then partially submerged to level
L to form the posterior wall, then the posterior wall is sprayed
with granulate sodium chloride, and then the envelope is cured and
soaked in water to rid the envelope of the sodium chloride and
expose the textured surface on the posterior wall.
[0046] Preferably, as to making the envelope 12 with a relatively
thin wall 32 and a relatively thick wall 34 having the textured
surface 18, a mandrel is dipped four times in the dispersion as
described above and the envelope is then cured (still on the
mandrel) at about 270.degree. F. for about 90 minutes. Then the
four-layer envelope and mandrel is cooled to room temperature and
inspected. If the envelope passes inspection, the envelope is
partially dipped, such that only about the posterior side of the
envelope is submerged in the dispersion. Then the mandrel having
the partial fifth layer is permitted to sit at room temperature for
about 2.5 minutes to about 5 minutes, whereupon the fifth layer is
sprayed with sodium chloride, which embeds itself in the fifth
partially stabilized layer. Then the mandrel having the fifth
partial layer embedded with sodium chloride is cured at about
270.degree. for about 90 minutes. Then the cured envelope (still on
the mandrel) is soaked in water for four to twelve hours or more to
dissolve the sodium chloride to remove it from the envelope and
expose the texture. Then the envelope is removed from the mandrel
and patched. The patch may include a valve for feeding the fill
material to the interior of the envelope. Or the valve may be
placed at another site on the envelope.
[0047] As to applying the textured surface 18 to implant 10 or 36,
the following U.S. Patents are hereby incorporated by reference in
their entireties: 1) U.S. Pat. No. 5,674,285 issued Oct. 7, 1997
and entitled Mammary Implant Having Shell With Unitary
Rough-Textured Outer Layer and 2) U.S. Pat. No. 5,022,942 issued
Jun. 11, 1991 and entitled Method Of Making Textured Surface
Prosthesis Implants.
[0048] As to the fill material 14, preferred fill materials include
saline and silicone gel. More preferably, the fill material is a
biocompatible responsive gel. As to biocompatible responsive gels,
the following U.S. Patent is hereby incorporated by reference in
its entirety: U.S. Pat. No. 5,662,708 issued Sep. 2, 1997 and
entitled Rheologically Modified And Osmotically Balanced Fill
Material For Implant.
[0049] The relative thicknesses of the anterior and posterior walls
in FIGS. 3A and 3B are exaggerated for clarity. In practice,
anterior wall 32 is preferably between about {fraction (12/1000)}
(0.012) inches thick and about {fraction (16/1000)} (0.016) inches
thick. Posterior wall 34 is preferably between about {fraction
(14/1000)} (0.014) inches thick and about {fraction (18/1000)}
(0.018) inches thick. The posterior wall 34 is preferably about
{fraction (2/1000)} (0.002) inches thicker than the anterior wall
32. Anterior wall 32' is preferably between about {fraction
(12/1000)} (0.012) inches thick and about {fraction (16/1000)}
(0.016) inches thick. Posterior wall 34' is preferably between
about {fraction (14/1000)} (0.014) inches thick and about {fraction
(18/1000)} (0.018) inches thick. The posterior wall 34' is
preferably about {fraction (2/1000)} (0.002) inches thicker than
the anterior wall 32'.
[0050] The present implants may include room temperature vulcanized
(RTV) envelopes. These envelopes are conventionally used with
saline fill materials. Saline fill materials tend to be more
abrasive, and RTV envelopes resist the abrasiveness of the saline
to a better degree than do envelopes that are cured at elevated
temperatures. In other words, an RTV envelope may include a
textured portion (such as on a posterior portion) and a portion
with a smooth surface (such as on an anterior portion).
[0051] The present implants are preferably breast implants and,
more preferably, anatomical-shaped breast implants.
Anatomical-shaped implants have a greater fullness in the inferior
pole. Or the anatomical-shaped implant may have a fullness in the
inferior pole as shown by implant 70 in FIG. 6A. Here, in FIG. 6A,
the roundness or elevation of the implant is shown by phantom
lines. The "highest" point on implant 70 is shown by point or
nipple region 72 and reference numeral 74 shows a line marking the
boundary between the anterior side 76 and the posterior side of
implant 70. Loops 78, 80 and 82 mark respective "elevations"
between nipple region 72 and boundary line 74 such that the breast
implant surface along phantom line 84 has the greatest slope and
such that the breast implant surface along phantom line 86 has the
least slope. The breast implant surfaces along phantom lines 88
have a progressively lesser slope than the surface along phantom
line 84, and these progressively lesser slopes continue between and
along surface lines 90, 92, and 94, which lines also radiate from
the nipple region 72.
[0052] The valve for filling the implant with fill material may be
located either posteriorally or anteriorally. A posterior valve 60
is shown in FIG. 1B. The valve 60 may be a leaf valve.
[0053] As shown in FIG. 1B, valve 60 is engaged to a patch 62.
Patch 62 is a piece of silicone elastomer that is vulcanized to the
envelope after the envelope has been removed from the mandrel. In
other words, the envelope is first formed by 1) dipping the mandrel
four times so as to produce a four layer envelope 2) curing the
envelope so that the envelope is vulcanized to a one layer
envelope, 3) partially dipping the mandrel and spraying the partial
layer with granulate sodium chloride, 4) curing the envelope so
that the partial layer is vulcanized to the envelope, 5) and then
soaking the envelope to remove the granulate sodium chloride and
expose the texture. Then the dipping rod 38, including distal end
49, is removed from the mandrel. A ragged piece of the envelope
remains about the area where the distal end 49 had engaged and had
been removed from the mandrel. This ragged piece is cut about a
line 64, shown in phantom in FIG. 4B. Then the envelope is
stretched about the opening left by such cutting such that the
mandrel passes through the stretched opening. Then valve 60 is
anchored to patch 62. Then patch 62 having valve 60 is vulcanized
to the envelope about the opening.
[0054] The surface of the patch 62 may, if desired, be the only
portion of the implant that is textured, as shown in FIG. 6B. The
texture 18 of this patch 62 sufficiently interlocks with body
tissue to minimize, if not prevent, rotation of implant 10 in the
body. Patch 62 has a diameter of about 25% of the diameter of the
implant 10.
[0055] The area of the surface texture 18 for interlocking with
body tissue for anchoring an implant to minimize or even prevent
rotation preferably has a surface area of between about 5% and
about 50% of the total surface area of the implant, more preferably
between about 5% and about 40% of the total surface area of the
implant, and most preferably between about 5% and about 30% of the
total surface area of the implant. The surface area of the patch 62
is about 5% of the total surface area of the implant 10 shown in
FIG. 6B. The surface area of the texture 18' of the round-shaped
implant 36 is about 50% of the total surface area of implant 36.
The surface area of the texture 18 on the posterior side of implant
10 in FIG. 1B is about 30% of the total surface area of the implant
10 of FIGS. 1A-D.
[0056] Preferably, the area of the surface texture 18 is on one
side or on less than one side of the implant and covers one portion
or block of surface of the implant without breaks in the texturing.
However, if desired, the surface texture 18 may form an annular
band about the circumference of the implant, or an annular band
along less than the circumference of the implant, or a band having
two ends along one side of the implant, or a band having two ends
along less than one side of the implant. Such bands of texturing
may be formed, for example, by placing a template over a partially
stabilized but not cured envelope, then spraying the granulate
sodium chloride over the template and exposed portion of the
partially stabilized but not cured envelope, then removing the
template, then curing the envelope, and then soaking the envelope
to remove the salt and expose the band of texture.
[0057] It should be noted that preferably the textured surface 18
has an aggressive texture and that preferably the smooth surface 30
is perfectly smooth or as perfectly smooth as is practically
possible through the process of dipping and curing a silicone
elastomer breast envelope. However, if desired, surface 18 may be
relatively rough and surface 30 may be relatively smooth. In other
words, it should be noted that some texture applied to implant
surfaces is very aggressive (has high peaks and low valleys, i.e.,
the absolute distance between the peaks and valleys is great), that
some texture applied to implant surfaces is subtle (has low peaks
and high valleys, i.e., the absolute distance between the peaks and
valleys is small), and that some texture is not so aggressive and
not so subtle.
[0058] An aggressive texture performs best for anchoring an implant
and such is preferred for a posterior side of a breast implant. On
the anterior side of such an implant, a perfectly smooth surface or
practically smooth surface is preferred. However, if desired, a
less aggressive or subtle texture (i.e. relatively smooth surface)
may be used.
[0059] As to forming an implant having both an aggressive texture
and a less aggressive texture, one side or one portion of the
envelope may be sprayed with relatively coarse granules of sodium
chloride and the other side or other portion of the envelope may be
sprayed with relatively fine particles of sodium chloride. Then the
envelope is cured and soaked to remove the salt and expose the
texture. The coarse particles produce the relatively aggressive
texture. The fine particles produce the relatively subtle
texture.
[0060] The present implants may be inflatable or prefilled
implants. In other words, either an inflatable implant or a
prefilled implant may include a textured surface portion (such as
on a posterior portion) and a portion with a smooth surface (such
as on an anterior portion). An inflatable anatomical shaped implant
100 is shown in FIG. 7A having no fill material therein. Implant
100 includes posterior face 16 with texture 18 and an anterior face
20 and smooth surface 30. An inflatable round shaped implant 102 is
shown in FIG. 7B having no fill material therein. Implant 102
includes posterior face 16 with texture 18 and an anterior face 20
and smooth surface 30. Implants 100 and 102 are manufactured
according to the processes described above. Generally, inflatable
implants are surgically implanted into the body and then filled
with fill material so as to expand the implant. Prefilled implants
are filled at the factory with fill material or filled with fill
material prior to being surgically implanted. The implants shown in
FIGS. 1A, 1B, 1C, 1D, 2A, 2B, 2C, 2D, 6A and 6B show prefilled
implants.
[0061] Thus since the invention disclosed herein may be embodied in
other specific forms without departing from the spirit or general
characteristics thereof, some of which forms have been indicated,
the embodiments described herein are to be considered in all
respects illustrative and not restrictive. The scope of the
invention is to be indicated by the appended claims, rather than by
the foregoing description, and all changes which come within the
meaning and range of equivalents of the claims are intended to be
embraced therein.
* * * * *