U.S. patent application number 13/685909 was filed with the patent office on 2013-12-12 for methods and apparatus for inhibiting scar formation.
This patent application is currently assigned to ZipLine Medical, Inc.. The applicant listed for this patent is Amir Belson. Invention is credited to Amir Belson.
Application Number | 20130331757 13/685909 |
Document ID | / |
Family ID | 45348514 |
Filed Date | 2013-12-12 |
United States Patent
Application |
20130331757 |
Kind Code |
A1 |
Belson; Amir |
December 12, 2013 |
METHODS AND APPARATUS FOR INHIBITING SCAR FORMATION
Abstract
Scar formation is inhibited by simultaneously applying a
vertical force and a lateral compression to the wound site during
the healing process. Apparatus for applying such simultaneous
forces comprise a backing and a tissue displacement device. The
backing holds the tissue displacement device over the wound. The
tissue displacement device may be expanded to both apply the
vertical force against the wound and to draw the backing radially
or laterally inward to apply the desired compression forces to the
wound.
Inventors: |
Belson; Amir; (Los Altos,
CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Belson; Amir |
Los Altos |
CA |
US |
|
|
Assignee: |
ZipLine Medical, Inc.
Los Altos
CA
|
Family ID: |
45348514 |
Appl. No.: |
13/685909 |
Filed: |
November 27, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/US2011/040213 |
Jun 13, 2011 |
|
|
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13685909 |
|
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61397604 |
Jun 14, 2010 |
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Current U.S.
Class: |
602/48 ;
602/53 |
Current CPC
Class: |
A61F 13/02 20130101;
A61F 13/023 20130101; A61B 2017/00557 20130101; A61B 17/085
20130101 |
Class at
Publication: |
602/48 ;
602/53 |
International
Class: |
A61F 13/02 20060101
A61F013/02 |
Claims
1. A method for inhibiting scar formation in a healing wound on a
skin surface, said method comprising applying a downward force on
the healing wound while simultaneously applying a lateral
compression force to tissue across the wound.
2. A method as in claim 2, wherein the forces are applied at a time
beginning from 1 day to 30 days after the wound began to heal.
3. A method as in claim 2, wherein the forces are applied for a
period of time in the range from 1 day to 21 days.
4. A method as in claim 3, wherein the force is increased at least
once during said period of time.
5. A method as in claim 3, wherein the force is deceased at least
once during said period of time.
6. A method as in claim 1, wherein applying the vertically downward
force comprises attaching a tissue displacement device on the skin
surface and then actuating the tissue displacement device to apply
said vertically downward force.
7. A method as in claim 6, wherein attaching comprises securing a
backing to tissue on either side of the healing wound and raising a
center of the backing with the tissue displacement device to draw
the sides of the backing laterally inwardly after the backing has
been secured.
8. A method as in claim 6, wherein attaching comprises wrapping a
backing around a limb, torso, or abdomen which comprises the skin
surface and healing wound and raising a portion of the backing over
the wound with the displacement device to draw the sides of the
backing inwardly.
9. A method as in claim 7, wherein the tissue displacement device
comprises a balloon having a relatively non-distensible bottom
surface which is applied against the wound and a relatively
distensible top surface which inflates upwardly to raise the
backing.
10. A method as in claim 8, wherein the tissue displacement device
comprises a balloon having a relatively non-distensible bottom
surface which is applied against the wound and a relatively
distensible top surface which inflates upwardly to raise the
backing.
11. A method as in claim 7, wherein the tissue displacement device
comprises a spring element that can be depressed to provide a
convex surface which engages and applies force to the wound.
12. A method as in claim 8, wherein the tissue displacement device
comprises a spring element that can be depressed to provide a
convex surface which engages and applies force to the wound.
13. Apparatus for inhibiting scar formation in a healing wound on a
skin surface, said apparatus comprising: an expandable structure
with a relatively non-distensible bottom surface for engaging the
wound and a relatively distensible top surface which moves upwardly
away from the bottom surface when actuated; and a backing having
two lateral regions adapted to adhere to skin on opposites of the
wound and a central section adapted to cover the expandable
structure when placed over the wound; wherein expansion of the
expandable structure causes the lower surface to apply downward
pressure against the wound and adjacent tissue and simultaneously
causes the top surface to rise and draw the lateral regions of the
backing inwardly to laterally compress the tissue adjacent the
wound.
14. Apparatus as in claim 13, wherein the expandable structure is
inflatable.
15. Apparatus as in claim 14, wherein the inflatable structure has
a flexible lower surface and an elastomeric upper surface so that
the upper surface deforms and moves away from the lower surface
while the lower surface remains dimensionally stable as the
structure is inflated.
16. Apparatus as in claim 15, wherein the inflatable structure has
a D-shaped profile when inflated.
17. Apparatus as in claim 13, wherein at least the lateral regions
of the backing are non-distensible.
18. Apparatus as in claim 13, wherein the entire backing is
non-distensible.
19. Apparatus as in claim 13, wherein the lateral regions each have
an adhesive surface which adheres to the skin.
20. Apparatus as in claim 13, wherein the expanded structure
comprises a plurality of segments joined along a line, where the
segments are displaceable relative to each other to allow the
structure to conform to a long wound.
21. Apparatus as in claim 20, wherein each segment is held onto the
skin by a separate backing.
22. Apparatus as in claim 13, wherein the expandible structure
comprises a spring element that can be depressed to provide a
convex surface which engages and applies force to the wound.
23. Apparatus as in claim 13, wherein a bottom surface of the
expandible structure is coated with a drug.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] The present application is a continuation of PCT Application
No. PCT/US2011/040213 (Attorney Docket No. 35383-705.601), filed
Jun. 13, 2011, which claims priority from provisional application
No. 61/397,604 (Attorney Docket No. 35383-705.101), filed on Jun.
14, 2010, the full disclosures of which are incorporated herein by
reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] Scarring is a natural response to the healing of wounds in a
patient's skin. The wound healing process can be divided into three
successive stages. A first inflammatory stage begins immediately
after the injury which caused the wound. The inflammatory stage
lasts up to a week during which time cellular processes remove
damaged tissue and foreign matter from the wound. The inflammatory
stage is followed by a proliferative stage which is characterized
by fibroblast proliferation and the production of collagen and
proteoglycans. The proliferative stage can last from days to weeks
and is typically the stage during which hypertrophic scar formation
begins, typically as a result of excess production of the extra
cellular matrix which is synthesized to heal the wound. Such scars
are referred to "hypertrophic scars." After the proliferative
stage, a remodeling phase begins where the matrix which was
produced in the proliferative is remodeled into an organized,
cross-linked structure which increases the mechanical strength of
the healed tissue.
[0004] Scars which are formed during the healing response are often
treated after the healing is complete by cosmetics or surgical
treatment. Cosmetic treatments are at best temporary solutions, and
the need to have subsequent surgery is both inconvenient and a risk
to the patient. It would therefore be desirable to provide methods
and apparatus which could diminish scar formation during the
healing process itself so that such subsequent procedures would be
unnecessary or at least reduced in scope.
[0005] 2. Description of the Background Art
[0006] WO/2011/019859 describes a device for inhibiting scarring in
skin wounds, where the device is fixed to the skin and applies an
outward force to spaced-apart skin locations. US2008/0069855
describes materials that will prevent scars and tissue adhesions.
U.S. Pat. Nos. 7,511,185, 4,702,251, 4,539,990 and 4,535,772
describe wound healing devices that apply laterally inwardly
opposed forces to the tissue on either side of the wound.
SUMMARY OF THE INVENTION
[0007] The present invention provides methods and apparatus for
inhibiting scar formation during the healing of a wound on a skin
surface. The term "scar" is intended includes not only common
hypertrophic scars which occurs from cuts, abrasions, and the like,
but also to include keloids which are hyperplastic masses that
occur in the dermis and adjacent subcutaneous tissue in certain
individuals, typically following trauma.
[0008] The methods and apparatus of the present invention treat
healing wounds by applying a downward force on the wound while
simultaneously applying a compression force in order to relieve
tension in the tissue across or surrounding the wound, usually
during the proliferative and/or remodeling stages of the wound
healing process. Treatment during the late portions of the
inflammatory stage might also be useful, and in some instances
treatment after remodeling might also be performed. For example,
simultaneous downward compression and lateral compression may
applied to the wound at or near the end of the inflammatory stage,
typically at a time in the range form 1 day to 30 days after the
wound occurred and first began to heal. After commencing treatment,
the forces may continue to be applied for a period of time in the
range from one day to 21 days, or longer, and the forces may be
increased, decreased, or held constant during the treatment
period.
[0009] Apparatus according to the present invention are specially
adapted to provide such simultaneous downward and lateral
compressive forces to the region of the wound in the skin,
typically comprising a tissue displacement device which can placed
on the skin surface to cover the wound itself as well as some
distance lateral to the wound, typically from several millimeters
to one or two centimeters or more on each side of the wound. The
tissue displacement device may be actuated to apply the desired
vertically downward force in a variety of ways as described
below.
[0010] The apparatus of the present invention will also typically
include a backing which can be secured to the skin on either side
of the healing wound, where the backing is typically adapted to
draw the skin surface and underlying tissue layers laterally
inwardly to provide the desired lateral compression and in turn
relieve tension in the tissue. In the described embodiments, the
inward lateral movement of the skin and underlying tissue will be
effected by raising a center of the backing (after the backing has
been applied to the skin surface), usually as a result of actuating
the tissue displacement device, to draw the sides of the backing
laterally inwardly.
[0011] The backing may comprise a strip or layer of material which
can be attached to the skin over the tissue displacement device,
with lateral regions of the backing adhering to the skin surface on
opposite sides of displacement device. Usually at least the lateral
portions of the backing will be non-distensible (resistant to
stretching or inelastic), and more usually the entire backing will
have limited stretchability or elasticity, often being entirely
non-distensible. By non-distensible, it is meant that the backing
material will have an elongation at break of less of less than 20%,
typically less than 15%, and often less than 10%. Alternatively,
the backing may comprise a strap or other longer structure which
can be wrapped around a patient's limb in order to constrain the
tissue displacement device on the skin surface above below.
[0012] In the exemplary embodiments, the tissue displacement device
comprises a balloon or other expandable device having a relatively
non-distensible bottom surface which is disposed against the wound
and a relatively distensible top surface which inflates upwardly to
raise a central region of the backing which in turn causes the
lateral portions of the backing to draw laterally inwardly to
provide the desired inward tissue compression.
[0013] In order to treat long wounds covering five centimeters, ten
centimeters, twenty centimeters, or longer, the apparatus of the
present invention can be formed in segments, each usually
comprising a separate backing and a separate tissue compression
device as described previously. The segments will be linked
together by flexible joints, links or other components which allow
the resulting assembly to conform to a skin surface and follow
irregular topology of the wound and skin. The resulting
"flexibility" is also useful in allowing the assembly to conform to
the skin surface when the patient moves or is moved by others. In
some embodiments, the joints will be formed as short tubes or other
structures capable of delivering an inflation medium to each
successive segment from either end of the assembly.
[0014] Still other apparatus could be constructed in accordance
with the principles of the present invention. For example, for
localized wounds, a circular, stretchable elastic backing having an
adhesive surface for adhering to the skin could be provided. By
initially stretching the elastic backing radially outwardly, for
example using a constraining frame or other component, the elastic
backing could be placed over the wound and released from its
constraint to apply the literally inward force to the wound. A
variety of tissue compression devices can be placed under or over
the backing in order to provide the vertical compression
desired.
[0015] Still alternative, apparatus could be provided including a
more rigid disk having an adhesive on an outer annular surface and
a center portion free from the adhesive that can be everted or
otherwise deformed to press inwardly against tissue and draw the
annular circumference of the disk inwardly to provide simultaneous
radial compression and vertical force. For example, the center
portion could "snap" from an everted configuration to an inverted
configuration much like a bottle top with an indication that the
top has been previously opened.
[0016] In still other embodiments, a lower of other surface of the
tissue displacement device may be coated with a drug to deliver
that drug to the skin during the treatment.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a schematic illustration of a wound showing
vertical and lateral force compression applied in accordance with
the principles of the present invention.
[0018] FIGS. 2, 2A and 2B illustrate a first apparatus and its use
for applying such vertical and lateral force compression.
[0019] FIG. 3 illustrates a segmented assembly constructed in
accordance with the principles of the present invention which can
be used for treating elongated or irregular wounds.
[0020] FIG. 4 illustrates an alternative apparatus for treating
wounds in accordance with the principles of the present
invention.
[0021] FIGS. 5A and 5B illustrate use of the apparatus of FIG. 4 in
treating a localized wound.
DETAILED DESCRIPTION OF THE INVENTION
[0022] FIG. 1 is a schematic diagram illustrating a subcutaneous
wound W in a skin surface S where the wound extends some distance
beneath the surface. To reduce scarring as the wound heals in
accordance with the principles of the present invention, a downward
or vertical force will be applied over a region spanning the wound
and extending from several millimeters to several centimeters or
longer onto the skin surface from each side of the wound as
generally indicated by the vertical arrows. Pressure is preferably
applied along most or all of the length of elongated. The cuts,
incisions, and other elongated wounds that are treated by the
present invention will typically extend into the dermis by several
millimeters or more. In addition to the vertical force, present of
the invention will provide a compressive force or pressure
indicated by arrows 12 preferably extending from the surface down
to a depth close to or equal to the depth of the wound.
[0023] Methods of the present invention for applying the forces
illustrated in FIG. 1 can be performed using a variety of
apparatus. One exemplary apparatus is illustrated in FIG. 2 and
includes both a backing 14 and a tissue displacement device 16
which can be assembled and used in combination for applying the
desired forces. The backing 16 will usually be non-distensible over
most or all of its length from end 18 to end 20. The length will
usually be in the range from 5 centimeters to 10 centimeters, 20
centimeters, or longer. The width will typically be in the range
from 1 centimeter to 5 centimeters. Backing will be divided into
regions, including a first lateral region 22 and a second lateral
region 24. At least a portion of each of these lateral regions will
be substantially non-distensible and they will have adhesive
surfaces 26 and 28 which can be applied to the skin to hold the
backing in place. A central region 14 of the backing between the
lateral regions 22 and 24 may have some ability to stretch
(distensibility), but the central region will also typically be
non-distensible over all or a portion of its length. The bottom
surface of this central region of the backing, however, will be
usually free from all adhesives so that the central region may be
placed over the tissue displacement device 16 with the central
region able to move over the top of the displacement device as the
displacement device is expanded as shown in broken line in FIG. 2.
The displacement device 16 will typically be formed from an elastic
material over its upper portions to allow the desired vertical
expansion while a bottom or base 30 of the device 16 resists
expansion. Thus, the upper surface 32 which is elastic can expand
to the extent shown in broken line when the device is actuated.
Usually, the tissue displacement device 16 will be an inflatable
structure, such as a balloon, where the thickness of and/or
reinforcement within the bottom of the structure resists stretching
and the upper portion is elastic to allow expansion upon inflation
of the structure. In other cases, a balloon or other inflatable of
expandable structure with a round or elliptical profile could be
used.
[0024] In use, the assembly of FIG. 2 is placed over a wound so
that the lateral regions 22 and 24 of the backing 14 adhere to the
skin's surface on opposite sides of the wound W. The tissue
displacement device 16 is held directly over the wound W by the
central section of the backing as shown in FIG. 2A, and the tissue
displacement device 16 then inflated to raise the central section
and as shown in FIG. 2B. By raising the central section 25, the
lateral portions 22 and 24 are drawn laterally inward to compress
the upper surface of the tissue which in turn compresses the tissue
on either side of the wound at the lower depths as shown by the
arrows in FIG. 2B. Simultaneously, the bottom of the tissue
displacement device applies a downward pressure over the wound as
indicated by the vertical arrows in FIG. 2B. The asymmetric
structure of the tissue displacement device allows this selective
application of forces to achieve the objectives of the present
invention. Each of the lateral portions 22 and 24 will be attached
on the skin surface up to a point P. the backing will be unattached
to the skin between point P and area covered by the tissue
displacement device 16. It is this short unattached region of the
backing which allows the lateral portions 22 and 24 to be drawn
inwardly without significantly pulling the skin upwardly, as shown
in FIG. 2B.
[0025] In order to treat lengthy wounds, the apparatus as generally
shown in FIG. 2, can be formed in multiple segments 40, as
illustrated in FIG. 3. Each segment 40 will generally have the
structure illustrated in FIG. 2, and adjacent segments will be
joined by short tubular connectors of links 42 which both hold the
segments together and which permit simultaneous inflation of each
of the tissue displacement devices 16. The segmented structure of
FIG. 3 is advantageous since it permits the assembly to follow
non-linear wounds and also allows the assembly to conform to the
tissue surface as the patient moves or is moved during the scar
treatment.
[0026] An alternative treatment device 50 is illustrated in FIG. 4.
The device comprises a backing 52 having an outer annular portion
54 which has an adhesive surface for attachment to the patient's
skin. The device 50 further includes a central section 54 which can
be everted or depressed in order to both apply vertical force to a
wound and simultaneously apply radially inward forces, as
illustrated in FIGS. 5A and 5B. Such an evertable central section
could also be used with the elongated or strip-like devices
described previously.
[0027] As shown in those FIGS. 5A and 5B, a localized
(non-elongated) wound W may be covered by the central portion 54 of
the device 50 while the annular portion 52 adheres to the skin
surrounding the wound. By then deforming and depressing the center
section 54 and shown in FIG. 5B, a vertical force is applied over
the wound while simultaneously the annular portion 52, which will
typically be elastic, is drawn inwardly to radially compress the
tissue about the wound.
* * * * *