# Patent

## Title
Method and apparatus for expanding tissue

## Abstract

An implantable tissue expander is provided for supporting a body tissue. The tissue expander includes an implantable support member that is externally positioned with respect to the body tissue to be shaped. The support member includes a first end and an opposing second end. The first end includes a first fastener configured to be inserted into the body tissue to secure the first end to a first portion of the body tissue. The second end includes a second fastener configured to be inserted into the body tissue to secure the second end to a second portion of the body tissue. The support member includes a biasing element configured to exert a tension force at each of the first end and the second end to shape the body tissue.

## Background
CROSS REFERENCE TO RELATED APPLICATIONS
This application is a continuation of U.S. patent application Ser. No. 11/256,906, filed Oct. 24, 2005, now U.S. Pat. No. 7,914,578 which is hereby incorporated by reference in its entirety.


BACKGROUND OF THE INVENTION
This invention relates generally to tissue expansion, and more particularly, to methods and apparatus for supporting, sculpting and/or shaping tissue.
Tissue expanders, such as implants, bladders, envelopes and the like, are typically placed within the body to expand, reconstruct, or otherwise augment missing or misshapen body tissue. For example, a tissue expander may be used to augment, sculpt, and support soft tissue, such as breast, penile, gluteal, and facial tissue.
Soft tissue augmentation and reconstruction, for example breast augmentation and reconstruction, is known and has been performed by physicians for decades. The use of silicone gel-filled implants may provide improved appearance, but silicone gel-filled envelopes create safety concerns for manufacturers, physicians, and patients due to possible leaks of the silicone gel into the body. Saline-filled implants have been used in place of silicone gel-filled implants, but have a less natural shape and consistency.
Another aspect in the field of breast augmentation and reconstruction is the use of tissue expanders. Tissue expanders typically include a bladder or envelope that holds a liquid, such as saline or a hydro-gel. The tissue expander is implanted under tissue, such as under the muscle below a surgically removed breast. A small amount of liquid is added to the envelope periodically until the desired size is reached. By adding liquid slowly over a period of weeks or months, the covering tissue is allowed to expand to accommodate its size. However, in order to change the volume of the tissue expander a needle must be inserted into the envelope each time.
BRIEF DESCRIPTION OF THE INVENTION
In one aspect, an implantable tissue expander is provided for supporting a body tissue. An implantable support member is externally positioned with respect to the body tissue to be shaped. The support member includes a first end and an opposing second end. The first end includes a first fastener configured to be inserted into the body tissue to secure the first end to a first portion of the body tissue. The second end includes a second fastener configured to be inserted into the body tissue to secure the second end to a second portion of the body tissue. The support member includes a biasing element configured to exert a tension force at each of the first end and the second end to shape the body tissue. The support member has shape memory properties and is adapted to move to a support configuration. In the support configuration, the support member shapes the body tissue.
In another aspect, an implantable tissue expander is provided for supporting a body tissue. The implantable tissue expander includes a support member adapted to be implanted and positioned externally with respect to the body tissue to be supported in a support configuration. A first end of the support member includes a first fastener configured to be inserted into a first portion of the body tissue to secure the first end to the first portion. An opposing second end of the support member includes a second fastener configured to be inserted into a second portion of the body tissue to secure the second end to the second portion. Each of the first end and the second end transitions into a body of the support member. The body includes a biasing element. In the support configuration, the biasing element exerts a force at each of the first end and the second end to support the body tissue.
In yet another aspect, a method is provided for supporting a body tissue. The method includes positioning at least one tissue expander externally with respect to the body tissue to be supported. The at least one tissue expander includes a biasing element. A first end of the at least one tissue expander is inserted into a first portion of the body tissue to secure the first end with respect to the first portion. A second end of the at least one tissue expander is inserted into a second portion of the body tissue to secure the second end with respect to the second portion. The at least one tissue expander is expanded to a support configuration. The biasing element exerts a force at the first end and the second end to support and shape the body tissue.



BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a front view of a tissue expander positioned with respect to a breast, according to one embodiment of this invention.
FIG. 2 is a partial cross-sectional view of the tissue expander shown in FIG. 1 positioned within a catheter delivery system, according to one embodiment of this invention.
FIG. 3 is a front view of a first tissue expander and a second tissue expander positioned with respect to a breast, according to one embodiment of this invention.
FIG. 4 is a front view of a tissue expander including a plurality of support members positioned with respect to a breast, according to one embodiment of this invention.
FIG. 5 is a front view of a tissue expander positioned with respect to a breast, according to one embodiment of this invention.
FIG. 6 is a front view of a tissue expander positioned with respect to a breast, according to one embodiment of this invention.
FIG. 7 shows the tissue expander of FIG. 6 positioned in a collapsed configuration within a catheter, according to one embodiment of this invention.
FIG. 8 is a side view of a tissue expander positioned with respect to a breast, according to one embodiment of this invention.



DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a front view of an implantable tissue expander 100 for supporting, shaping and/or sculpting a body tissue. While the tissue expander is described in terms of certain specific embodiments, it is not intended to be limited to these embodiments. For example, components used within the tissue expander may have a variety of shapes, sizes, and/or uses. It will be apparent to one of ordinary skill in the art, however, that the tissue expander may be practiced without limitation to any specific detail presented herein. For example, tissue expander 100 can be used in conjunction with a plurality of delivery systems including, but not limited to, a catheter delivery system and a surgical implantation system.
Referring to FIG. 1, in an exemplary embodiment, a breast 102 is illustrated with tissue expander 100 positioned at a base portion 104 of breast 102. The invention is not limited to the expansion, reconstruction, and/or augmentation of a breast. For example, the invention may be used to expand, reconstruct, and/or augment penile, gluteal, and/or facial tissue. Furthermore, the invention may be used in a variety of soft body tissue areas where expansion, reconstruction, and/or reconstruction is practiced.
In the exemplary embodiment, tissue expander 100 includes a support member 105 having a first end 106, an opposing second end 108, and a body 110 extending therebetween, as shown in FIG. 1. Tissue expander 100 may have any suitable size and/or shape. In the exemplary embodiment, tissue expander 100 has a generally arcuate or semi-circular shape or configuration. In alternative embodiments, the shape and/or size of tissue expander 100 is selected to correspond to a shape, a size, and/or location of the body tissue within the patient's body. For example, in alternative embodiments, support member 105 is one of a rod, a wire, and a ribbon having flat surfaces and/or round surfaces, and having a hollow or solid cross-sectional area.
Tissue expander 100 is adapted to expand from an initial insertion configuration to a support configuration for supporting and/or shaping the body tissue. In the exemplary embodiment, tissue expander 100 has a circular cross-section and is radially expandable. In one embodiment, tissue expander 100 is radially expandable between a generally unexpanded or insertion diameter and an expanded or support diameter which is greater than the insertion diameter. As such, tissue expander 100 is flexible and can be coupled to a catheter in a radially compressed configuration, i.e. the insertion configuration, for introduction and positioning with respect to the body tissue. Upon positioning of tissue expander 100, tissue expander 100 is expandable to the support configuration. In one embodiment, tissue expander 100 is expandable using a spring-like action and/or memory properties of the material, for example. As such, tissue expander 100 is radially distensible and/or deformable. In one embodiment of this invention, tissue expander 100 includes support member 105 fabricated using a suitable material having shape memory properties that are effected by changes in temperature or that have super elastic properties. It will be understood that various other means for expanding or enabling the expansion of tissue expander 100 may be employed without departure from the scope of this invention.
In one embodiment, tissue expander 100 including support member 105 is fabricated from any suitable biocompatible material including, without limitation, suitable metal materials, such as stainless steel, platinum, gold, titanium, and alloys and/or composites thereof, as well as suitable polymeric materials. In the exemplary embodiment, tissue expander 100 is fabricated from Nitinol which has the ability to perform well while in a spring-like configuration, and/or in a shape memory configuration.
In an alternative embodiment, tissue expander 100 includes a plurality of magnets and/or magnetic components positioned with respect to tissue expander 100 to affect a final shape of tissue expander 100 in the support configuration. For example, a first magnet is positioned at first end 106 of support member 105 and a second magnet is positioned at opposing second end 108 to magnetically move first end 106 towards or away from second end 108 and, thus, support and/or shape the body tissue.
FIG. 2 is a partial cross-sectional view of tissue expander 100 positioned within a catheter delivery system 150. In the exemplary embodiment, tissue expander 100 is configured to be delivered by catheter system 150. For example, tissue expander 100 is bendable or shapeable into an insertion configuration for positioning within catheter delivery system 150. Catheter delivery system 150 is inserted into the patient's body by percutaneous delivery. A guide wire is used to advance catheter delivery system 150, depending on the location of the soft body tissue within the patient's body. In one embodiment, tissue expander 100 and a tissue expander 200 are introduced using catheter delivery system 150 and at least a portion of tissue expander 100 and tissue expander 200 are aligned with each other, as shown in FIG. 3. In one embodiment, at least one radio-opaque marker is utilized to monitor the alignment of tissue expander 100 with tissue expander 200. Alternatively, tissue expander 100 is introduced using catheter delivery system 150 and tissue expander 200 is introduced using a second catheter delivery system, similar to catheter delivery system 150, without using radio-opaque markers.
As shown in FIG. 2, catheter delivery system 150 includes a catheter 151 forming a chamber 153. Tissue expander 100 is positionable within chamber 153 in an insertion configuration for introduction into the desired body tissue region or location. In the insertion configuration, tissue expander 100 is generally straight or linear. A catheter sheath 152 covers at least a portion of tissue expander 100 in the insertion configuration for introduction into the desired body tissue region or location. Catheter sheath 152 forms a housing, a sleeve, a sock or a suitable assembly for surrounding and retaining tissue expander 100 in the unexpanded or insertion configuration within catheter delivery system 150. As such, in the exemplary embodiment, sheath 152 is tubular in shape. In the exemplary embodiment, sheath 152 is sized to overlay at least tissue expander 100 and catheter 151. In alternative embodiments, sheath 152 may have any suitable shape and/or size. In one embodiment, sheath 152 is a retractable. In another embodiment, sheath 152 is configured to move in a distal direction and a proximal direction with respect to or along catheter 151 to aid in the deployment of tissue expander 100. In one aspect, sheath 152 has a yield strength greater than an expansion force of tissue expander 100. As such, sheath 152 retains tissue expander 100 in the unexpanded or insertion configuration during delivery and introduction of tissue expander 100.
During positioning of tissue expander 100 with respect to breast 102, sheath 152 retracts to proximally release tissue expander 100. In one embodiment, tissue expander 100 begins to expand as it exits sheath 152. In another embodiment, tissue expander 100 expands at a selected temperature. In yet another embodiment, a balloon is inflatable to expand tissue expander 100. After deployment of tissue expander 100, catheter 151, including sheath 152, is withdrawn from the body tissue location, leaving tissue expander 100 properly positioned with respect to the body tissue.
Exemplary embodiments of tissue expanders are described below. The embodiments described herein are illustrated with reference to the figures wherein similar numbers indicate the same elements in all figures. Such figures are intended to be illustrative rather than limiting and are included herewith to facilitate explanation of an exemplary embodiment of the tissue expander.
FIG. 3 is a front view of tissue expander 100 and a second tissue expander 200. Tissue expander 200 is similar to tissue expander 100 except as specifically set forth below. Tissue expander 100 and tissue expander 200 are positioned generally vertically with respect to opposing side portions of breast 102 and provide support to breast 102 superiorly to inferiorly.
FIG. 4 is a front view of a tissue expander 300. In the exemplary embodiment, tissue expander 300 includes a plurality of support members 302. In this embodiment, each support member 302 is similar to support member 105, discussed above, and connected to adjacent support members 302 at opposing end portions of tissue expander 300. Each support member 302 is expandable with respect to adjacent support members 302 to form tissue expander 300 for supporting and/or shaping the body tissue, as shown in FIG. 4. In one embodiment, tissue expander 300 has a shape that is one of arcuate and semi-circular with a curvilinear cross-section. In alternative embodiments, tissue expander 300 has a triangular shape. Tissue expander 300 is configured to be positioned in or with respect to a lower portion 304 of breast 102, as shown in FIG. 4, to support, shape and/or sculpt breast 102.
Tissue expander 300 is flexible and can be initially coupled to a catheter delivery system, such as catheter delivery system 150, in a compressed insertion configuration and expanded within the body tissue location to a support configuration. Each support member 302 of tissue expander 300 is expandable using a spring-like action and/or shape memory properties of the material, for example. In one embodiment, support members 302 include a suitable material having shape memory properties reactive or responsive to temperature changes. As such, support members 302 are distensible and/or deformable.
FIG. 5 is side view of a mesh tissue expander 400. In the exemplary embodiment, tissue expander 400 has a tubular mesh configuration and is radially expandable. In one embodiment, mesh tissue expander 400 is radially expandable between a generally unexpanded or insertion configuration having an insertion diameter and an expanded or support configuration having a support diameter which is greater than the insertion diameter. As such, mesh tissue expander 400 is flexible and can be initially coupled to a catheter in a radially compressed insertion configuration and expanded within the body tissue location to a support configuration. In one embodiment, tissue expander 400 is expandable using a spring-like action and/or shape memory properties of the material, for example. Tissue expander 400 includes a suitable material having shape memory properties reactive or responsive to temperature changes. In another embodiment, tissue expander 400 is expandable by balloon expansion or inflation. As such, tissue expander 400 is radially distensible and/or deformable. Other suitable means for expanding or enabling the expansion of tissue expander 400 may be employed without departure from the scope of this invention.
In one embodiment, tissue expander 400 is fabricated from Nitinol. Other suitable biocompatible materials, including metal materials, such as stainless steel, platinum, gold, titanium, alloys and/or composites, as well as polymeric materials can be used to fabricate tissue expander 400.
FIG. 6 is a front view of a tissue expander 500. In the exemplary embodiment, tissue expander 500 is fabricated using a suitable biocompatible material, such as materials discussed above in reference to tissue expanders 100 and 400. In the exemplary embodiment, tissue expander 500 has a generally spherical shape having a hollow interior. In alternative embodiments, tissue expander 500 has a generally solid interior. Tissue expander 500 is radially expandable between a generally unexpanded or insertion configuration having an unexpanded or insertion diameter and an expanded or support configuration having an expanded or support diameter which is greater than the insertion diameter. Tissue expander 500 is inserted into the patient's body using a suitable insertion instrument, such as catheter delivery system 150. After tissue expander 500 is positioned with respect to the body tissue, as desired, tissue expander 500 expands and increases in diameter from the insertion diameter to the desired or selected support diameter to support, sculpt, and/or shape the body tissue.
In one embodiment, tissue expander 500 is initially positioned in a collapsed position about or within a catheter 502, as shown in FIG. 7. A sheath 504 is positioned about tissue expander 500 and at least a portion of catheter 502. In the collapsed position, tissue expander 500 is positioned with respect to the body tissue, as desired. In one particular embodiment, a suitable guide wire 506 positions tissue expander 500. With tissue expander 500 positioned as desired, sheath 504 is movable along a length of catheter 502 to expose tissue expander 500. Tissue expander 500 expands, as shown in FIG. 6, to support, sculpt, and/or shape the body tissue. In one embodiment, a balloon is used to expand tissue expander 500. Tissue expander 500 increases in volume to expand to a generally spherical shape having a hollow interior. In alternative embodiments, tissue expander 500 has a generally solid interior in the expanded configuration. Further, in alternative embodiments, tissue expander 500 has any suitable expanded shape. In this embodiment, tissue expander 500 is fabricated using a Nitinol material skeleton including a covering cloth. In alternative embodiments, tissue expander 500 includes the skeleton without the covering cloth.
In one embodiment, implantable tissue expander 600 is adaptable to be positioned with respect to a body tissue, for example a breast 102 as shown in FIG. 8, to support, sculpt, and/or shape the body tissue.
Tissue expander 600 is flexible and can be initially coupled to a catheter delivery system, such as catheter delivery system 150, in a compressed insertion configuration and expanded within the body tissue location to a support configuration. Tissue expander 600 is expandable using a spring-like action and/or shape memory properties of the material, for example. In one embodiment, tissue expander 600 includes a suitable material having shape memory properties reactive or responsive to temperature changes. As such, tissue expander 600 is distensible and/or deformable.
Tissue expander 600 includes a support member 602 adapted to be positioned with respect to breast 102 in a support configuration, as shown in FIG. 8. In one embodiment, first end 604 of support member 602 is positioned with respect to a first portion of breast 102, for example a superior region or location 103 of breast 102. An opposing second end 606 of support member 602 is positioned with respect to a second portion of the body tissue, for example an inferior or base region or location 104 of breast 102. It is apparent to those skilled in the art that support member 602 may be positioned in any desirable orientation or position with respect to breast 102. For example, support member 602 may be positioned in a generally vertical orientation or position with respect to breast 102, as shown in FIG. 8. In an alternative embodiment, support member 602 is positioned in a generally horizontal or lateral orientation or position with respect to breast 102. In a further embodiment, one or more support members 602 are used in one or more of a generally vertical, lateral and/or diagonal orientation or position to support, sculpt, and/or shape breast 102, as desired.
In one embodiment, first end 604 forms or includes a suitable fastener 612 such as at least one hook or needle, which is inserted into the body tissue to secure first end 604 to superior region 103 of breast 102. Similarly, a suitable fastener 612 connected to or formed by second end 606 is inserted into the body tissue to secure second end 606 to inferior region 104 of breast 102. It is apparent to those skilled in the art that fastener 612 may include any suitable fastener or connector that can be inserted into the body tissue and remain securely connected to the body tissue to maintain first end 604 and second end 606 properly positioned with respect to the body tissue.
First end 604 and second end 606 transition into a body 608 of support member 602. In one embodiment, body 608 includes a biasing element 610, such as a spring, a coil and/or at least one magnet, which provides a force suitable to support, sculpt, and/or shape the body tissue, as desired. In the support configuration, biasing element 610 exerts a tension force at first end 604 and/or second end 606 to support breast 102. In one embodiment, biasing element 610 is generally positioned at a mid-section of support member 602 to provide a generally equal amount of force to first end 604 and second end 606. In another embodiment, biasing element 610 is positioned on support member 602 at a suitable location to provide a desired or selected force to first end 604 and/or second end 606.
While the invention has been described in terms of various specific embodiments, those skilled in the art will recognize that the invention can be practiced with modification within the spirit and scope of the claims.

## Claims

1. An implantable tissue expander for supporting a body tissue comprising:
an implantable support member externally positioned with respect to the body tissue to be shaped, said support member comprising a first end and an opposing second end, said first end comprising a first fastener configured to be inserted into the body tissue to secure said first end to a first portion of the body tissue, said second end comprising a second fastener configured to be inserted into the body tissue to secure said second end to a second portion of the body tissue, said first fastener and said second fastener each including at least one of a hook and a needle, said support member comprising a biasing element comprising one of a spring, a coil, and at least one magnet configured to exert a tension force at each of said first end and said second end to shape the body tissue, said support member having shape memory properties and adapted to move to a support configuration, said support member configured to shape the body tissue when said support member is in said support configuration.

2. A tissue expander in accordance with claim 1 wherein said support member is reactive to a temperature change.

3. A tissue expander in accordance with claim 1 wherein said support member comprises Nitinol.

4. A tissue expander in accordance with claim 1 wherein, in said support configuration, said support member exerts radial pressure against the body tissue to shape the body tissue.

5. A tissue expander in accordance with claim 1 further comprising a balloon, said balloon inflatable to expand said support member to said support configuration.

6. A tissue expander in accordance with claim 1 wherein said tissue expander is positionable one of laterally and vertically with respect to the body tissue.

7. A tissue expander assembly comprising:
said implantable tissue expander of claim 1; and
a catheter configured to deliver said tissue expander to a first body tissue location.

8. A tissue expander assembly in accordance with claim 7 further comprising a second implantable tissue expander positioned with respect to the body tissue and adapted to expand to a support configuration to shape the body tissue at a second body tissue location.

9. A tissue expander assembly in accordance with claim 8 wherein said second implantable tissue expander cooperates with said first tissue expander to shape the body tissue.

10. A tissue expander assembly in accordance with claim 7 wherein said catheter comprises a sheath, said sheath retaining said tissue expander in an unexpanded configuration within said catheter.

11. An implantable tissue expander for supporting a body tissue comprising:
a support member adapted to be implanted and positioned externally with respect to the body tissue to be supported in a support configuration, a first end of said support member comprising a first fastener configured to be inserted into a first portion of the body tissue to secure said first end to the first portion and an opposing second end of said support member comprising a second fastener configured to be inserted into a second portion of the body tissue to secure said second end to the second portion, said first fastener and said second fastener each including at least one of a hook and a needle, each of said first end and said second end transitioning into a body of said support member, said body including a biasing element comprising one of a spring, a coil, and at least one magnet, said biasing element configured to exert a force at each of said first end and said second end to support the body tissue when said support member is in said support configuration.

12. A method for supporting a body tissue, said method comprising:
positioning at least one tissue expander externally with respect to the body tissue to be supported, the at least one tissue expander including a biasing element;
inserting a first end of the at least one tissue expander into a first portion of the body tissue to secure the first end with respect to the first portion, the first end including at least one of a hook and a needle;
inserting a second end of the at least one tissue expander into a second portion of the body tissue to secure the second end with respect to the second portion, the second end including at least one of a hook and a needle; and
expanding the at least one tissue expander to a support configuration, wherein the biasing element exerts a force at the first end and the second end to support and shape the body tissue.

13. A method in accordance with claim 12 further comprising introducing the at least one tissue expander by percutaneous delivery using a catheter delivery system having a sheath, the at least one tissue expander initially positioned within the sheath in an insertion configuration.

14. A method in accordance with claim 13 wherein a plurality of tissue expanders are positioned with respect to the body tissue.

15. A method in accordance with claim 12 wherein a first tissue expander is positioned at a first location of the body tissue and a second tissue expander is positioned at a second location of the body tissue, and the first tissue expander and the second tissue expander cooperate to support and shape the body tissue.

16. A method in accordance with claim 12 wherein the at least one tissue expander is positioned one of laterally and vertically with respect to the body tissue.