FIELD OF THE INVENTION

The present invention generally relates to absorbable implants that are shaped or have shaped memory so they can conform to anatomical structures or confer shape to anatomical structures, and are designed for use in plastic surgery procedures.

BACKGROUND OF THE INVENTION

Numerous plastic surgery procedures are performed each year to restore or correct the form or function of the body. Many of these procedures seek to restore a youthful appearance, or even to enhance one's existing appearance. Natural factors, such as aging and gravity, contribute to the loss of the youthful appearance. For example, skin laxity, loss of muscle tone, and attenuation of ligaments can result in ptosis (drooping) of the breast. Plastic surgeons have developed a plethora of surgical techniques to correct the ptosis of different anatomical structures that occurs with aging. These techniques vary in the type of incision, direction of incision, plane of dissection, amount of dissection, extent of repositioning of tissue, the use of different types of sutures, different suturing techniques, and different fixation techniques. Almost all of them rely on the use of the pre-existing skin envelope as the support system for the newly lifted tissue. These approaches almost invariably result in recurrent ptosis, since the surgeon is merely relying on the aging and sagging surrounding tissues that have already failed to provide the necessary support to maintain a normal appearance. For example, de-epithelialization, flap transposition, gland repositioning or suturing will not alter the physical properties of the patient's tissue. At most, these techniques only slow recurrent ptosis by creating internal scars that provide limited reinforcement. And even the scarring process varies from patient to patient making this limited approach highly unpredictable. Notably, there is no attempt with these approaches to change the physical properties of the local tissue in order to improve the outcome.

Several surgeons have attempted to reinforce their lift procedures using surgical meshes in mastopexy and breast reconstruction procedures. Some of these techniques have also incorporated the use of various reinforcing materials similar to those used in hernia repair, such as flat polymeric meshes, allografts, xenografts and autografts.

In 1981, Johnson described the use of MARLEX® (cryastalline polypropylene) mesh to convert the support of breast tissue after mastopexy from a cutaneous origin to a skeletal origin by attaching the mesh to the area of the second rib, (Johnson,Aesth. Plast. Surg.5:77-84 (1981)). The flat MARLEX® mesh is a permanent mesh made from polypropylene, and was implanted to provide two slings in each breast that supported the breast tissue. It is not replaced with regenerated host tissue.

Auclair and Mitz have described a mesh assisted mastopexy using a flat absorbable mesh and a periareolar skin resection technique (Auclair and Mitz,Ann. Chir. Plast. Esthét.38:107-113 (1993)). A rapidly absorbing VICRYL® mesh was placed around the anterior surface of the breast gland in order to form an internal bra.

Góes has reported the use of polyglactin 910 (an absorbable copolymer of 90% glycolide and 10% L-lactide, also known as VICRYL®) and a mixed mesh (containing 60% polyglactine 910 and 40% permanent polyester) in a periareolar mammoplasty using a double skin technique (Góes,Plast. Reconstr. Surg.97:959-968 (1996)). The technique involves dissecting the soft tissue envelope away from the parenchyma, and wrapping the breast parenchyma with a mesh to help provoke the formation of a vigorous connective scar to produce a breast lining structure that would be less susceptible to ptosis. The soft tissue envelope is then closed around the parenchyma. In the procedure, a dermal flap was created around the nipple-areolar complex, and after the lift procedure was completed, the dermal flap was sutured on top of the breast gland to provide an internal cutaneous lining. The mesh was then sutured on top of the dermal flap so that it surrounded the breast gland, and the ends of the mesh were sutured together in the central part of the superior aspect of the breast to form a conical breast shape with slight elevation of the breast. Although the mesh was found to provide short-term support, it was absorbed after 3 months. Better results were reported with the mixed (partially absorbable) mesh. The latter provided a less elastic envelope, avoided tissue displacement, and improved the quality and duration of the new breast shape (Sampaio Góes,Clin. Plast. Surg.29:349-64 (2002)).

U.S. Pat. No. 6,210,439 to Firmin et al. discloses a circular VICRYL® mesh with a V-shaped opening extending from its center that has a metallic reinforcing wire running around the periphery. The implant assumes a conical shape suitable for mammoplasty when the reinforcing wire is tightened. However, VICRYL®mesh degrades rapidly in vivo with 50% loss of strength retention at five days, no residual strength at 10-14 days, and complete absorption at 42 days. This strength retention profile provides very little time for the formation of regenerated host tissue that can withstand the forces exerted on the breast. In fact, Góes and Bates concluded “absorbable synthetic meshes do not persist sufficiently to have an impact on the recurrence of breast ptosis” [see Góes and Bates, Periareolar mastopexy with FortaPerm,Aesth. Plast. Surg.34:350-358 (2010)].

WO 2009/001293 by de Bruijn et al. also discloses permanent mesh implants for use in mesh assisted mastopexy (see also de Bruijn et al.,Aesth. Plast. Surg.32:757-765 (2008)). These implants were performed in the shape of oblique circular cones with the apex removed so that they could be placed all the way around the entire breast gland with the nipple-areolar complex remaining exposed (effectively making an internal bra). The cones were made from two different non-degradable materials, polypropylene and a permanent polyester material. The results obtained with the softer polyester cone implants were considered to be superior to those achieved with the more rigid polypropylene implants. In the latter case, rippling of the polypropylene mesh in some patients resulted in a less than satisfactory appearance, the margins of the mesh were often palpable, and in some cases extrusion of the mesh occurred. Examination of the polyester mesh removed from a patient in pain was reported to show that the mesh appeared to possess the proper mechanical characteristics necessary to reinforce a ptotic breast during mastopexy (de Bruijn et al.,Plast. Reconstr. Surg.124:364-71 (2009)).

Van Deventer et al. has also reported the use of an internal breast support system for mastopexy using a partially degradable mesh that was formed into a cone by overlapping the ends of the mesh (van Deventer et al.Aesth. Plast. Surg.36:578-89 (2012)). The mesh contained 50% polypropylene and 50% absorbable polyglactin.

A permanent implant for soft tissue support, made from polytetrafluoroethylene (ePTFE), which can be used in forming a predetermined breast shape is disclosed by WO 2004/096098 by Hamilton et al. WO 2006/117622 by Lauryssen et al. also discloses a permanent implant for soft tissue support of the breast that is generally L-shaped or U-shaped, but is made from polypropylene.

U.S. Pat. No. 7,476,249 to Frank discloses an implantable sling shaped prosthesis device for supporting and positioning a breast implant in a patient, wherein the device is configured from a sheet of a chemically inert permanent material, such as polytetrafluoroethylene or silicone, to support the breast implant. The sling shaped device provides support to the breast but does not have shape memory that allows it to confer shape to the breast or retain a three-dimensional shape.

U.S. Patent Application Publication No. 2009/0082864 by Chen et al. also discloses a prosthetic device for supporting a breast implant made from a mesh. The device has a flat back wall, a concave front wall, and a curved transitional region between these walls that forms a smoothly curved bottom periphery.

U.S. Pat. No. 7,670,372 to Shfaram et al. discloses a minimally invasive breast lifting system. The system incorporates a biological material, such as tendons, or synthetic material, such as silicone or GOR-TEX® material (polytetrafluoroethylene), to cradle the breast.

U.S. Patent Application Publication No. 2012/0283826 by Moses et al. discloses mastopexy systems having an insertion device, a suspension strut, and a lower pole support. The implanted suspension strut provides pole projection and attachment points for the lower pole support, and the lower pole support can lift the lower pole of the breast.

U.S. Patent Application Publication No. 2008/0097601 by Codori-Hurff et al. discloses mastopexy and breast reconstruction procedures assisted by the use of processed tissue material derived from intestine or dermis. The tissue material is cut to a crescent shape, and may have up to 10 layers bonded together. The bonded layers can be chemically cross-linked.

U.S. Patent Application Publication No. 2008/0027273 by Gutterman discloses a minimally invasive mastopexy system having a soft tissue support sling. The latter can be made from polyethylene, PEBAX® (polyether block amide), PEEK (polyether ether ketone), nylon, PET (polyethylene terephthalate), ePTFE (polytetrafluoroethylene), silicone, or even a metal lattice. The device is designed to provide support by suspending the breast from the upper pole region using a bone anchor. The device does not have shape memory, and does not use shape memory to confer shape to the breast.

U.S. Patent Application Publication No. 2010/0331612 by Lashinski et al. discloses a system for performing a minimally invasive mastopexy (breast lift) that can include an elongate flexible sling used as a soft tissue anchor. The sling can be made from a mesh, and the mesh can be made, for example, from polypropylene. The sling is designed to resist weakening or degradation when implanted.

Notably, there is very little innovation in the design of flat meshes that when implanted can provide a specific conformation to the inferior support envelope without bunching or rippling. The problems associated with permanent mesh could be overcome by using an absorbable implant that is replaced with regenerated host tissue capable of supporting the reconstructed breast. Ideally, the absorbable implant would be pre-shaped to ensure a good outcome, and for ease of use. Notably, there are no disclosures of the use of any pre-shaped asymmetric absorbable implants for use in mastopexy or breast reconstruction. Prior disclosures have only described symmetrical two-dimensional shapes, such as ellipse shaped implants, which wrinkle, bunch or fold when the implant is attached to the breast mound and the fascia (see, for example, U.S. Patent Application Publication No. 2008/0097601 by Codori-Hurff et al.), pre-shaped hammocks and slings which are symmetrical three-dimensional shapes that are designed to conform to the lower pole of the breast (see, for example, U.S. Pat. No. 7,476,249 to Frank which discloses an implantable sling), or pre-shaped symmetrical cone shaped implants [de Bruijn et al.,Aesth. Plast. Surg.32:757-765 (2008)]. In order to make implants that conform to the anatomy of the breast and anchor to the chest wall, the plastic surgeon needs to trim, cut, or excise material from the implant.

PCT/US2012/027975 by Galatea Corporation discloses mastopexy systems to provide superior pole projection, to prevent ptosis recurrence, which may include tabs to enhance positioning.

U.S. Patent Application Publication No. 20120185041 to Mortarino et al. discloses methods for using silk meshes in breast augmentation and breast reconstruction with a knit pattern that substantially prevents unraveling when cut. Mortarino does not disclose silk meshes with shape memory, asymmetric or three-dimensional shapes. Mortarino also does not disclose meshes with shape memory that confer shape to a breast.

It is therefore an object of the invention to provide scaffold implants strong enough to support a lifted breast with or without a breast implant wherein the scaffold allows a transition from support by the implant to support by regenerated host tissue without any significant loss of support for the breast.

It is another object of the invention to provide implants that have suture pullout strengths strong enough to support the weight of a breast and/or a breast augmented with a breast implant.

It is still another object of the invention to provide implants that have a shape and design that upon placement, substantially conforms to the breast and chest wall without buckling or bunching, and sculpts the breast into the desired shape.

It is yet another object of the invention to provide shape memory implants for use in mastopexy and breast reconstruction procedures that can be temporarily deformed, and have the ability to spring open into a three-dimensional shape after delivery into a suitably shaped tissue plane of the body.

It is still further an object of the invention to provide shape memory implants for use in mastopexy and breast reconstruction procedures that confer shape on the breast, and can take the shape of the lower pole of the breast, and implants that are self-reinforced so they possess shape memory and can open into three-dimensional shapes.

SUMMARY OF THE INVENTION

Absorbable implants for use in breast surgery that are designed to conform to the breast parenchyma and surrounding chest wall have been developed. These implants are designed to support newly lifted breast parenchyma, and/or a silicone breast implant. The implants have initial mechanical properties sufficient to support a breast, with or without a breast implant, and allow the in-growth of tissue into the implant as the implant degrades. The implants also have a strength retention profile that allows the support of the breast to be transitioned from the implant to regenerated host tissue without any significant loss of support for the reconstructed breast. The implants can be made from poly-4-hydroxybutyrate (P4HB) and copolymers thereof. The implants have suture pullout strengths that can resist the mechanical loads exerted on the breast.

In one embodiment, the implants have a shape that: is conformable to the breast and chest wall without causing buckling or bunching; minimizing the need to trim the implant during surgery; and sculpturing the breast into the desired shape.

Absorbable implants are also disclosed with shape memory. These shape memory implants can be temporarily deformed, and can be delivered by minimally invasive techniques for mastopexy and breast reconstruction procedures. The implants can resume their preformed shapes after delivery into a suitably shaped tissue plane in the body. The shaped memory implants can confer a shape to the breast. In a preferred embodiment, the absorbable implants have an asymmetric shape.

