Title of Invention

A SUBCUTANEOUS TISSUE EXPANDER

Abstract

A tissue expander made of a biocompatible material, for being implanted subcutaneously, comprises and expandable pouch with a tube integrally attached thereto; a remote valve member having a chamber, with a tube integrally attached thereto, said member comprising first and second opposed parts, the first part being made of a self-sealing material; at least one non-metallic connector tube for interconnecting the tubes of the said expandable pouch and of the valve member, such that the needle of a hypodermic syringe introduced into the valve member, through the first part thereof, is enabled to inject saline into the chamber of the valve member, whence the saline passes through the connector tube into the pouch, for inflating the same, characterised in that the other part of the said valve member is sufficiently tough to serve as an impenetrable non-metallic needle stopper; and further characterized in that the portion of the pouch intended to be in contact with tissue to be expanded, is more elastic than the remaining portion thereof, to thus provide differential expansion of the pouch.

Full Text

This invention relates to a subcutaneous tissue expander. Subcutaneous tissue expanders are known to the art and are intended for use as temporary devices that are surgically placed under the muscle or in subcutaneous soft tissue. Tissue expanders are intended to be inflated in situ, at intraimplant pressures sufficient to stretch soft tissue. When expansion is accomplished by percutaneous hypodermic needle penetration of the tissue expander's injection port, multiple injections are typically required, spaced over a variable time period in order to achieve adequate expansion. The tissue expander is intended for use in plastic surgery, for reconstruction of tissue defects and deficiencies, by the development of tissue flaps. Tissue expanders are usually fabricated from high quality biocompatible si 1icone rubber. The tissue expander is placed subcutaneously and inflated periodical ly with saline solution until the tissue is developed sufficiently. According to one feature of this invention the valve member of the tissue expander proposed herein has no metallic component. Thus it is provided with a non-metallic needle stopper which will enable trouble free CT or MRI scanning for the patient if required. Another feature of this invention is that the portion of the pouch intended to be in contact with tissue to be expanded, is more elastic than the remaining portion thereof, to thus provide differential expansion of the pouch, whereby greater emphasis is laid on the development of the tissue to be expanded. The tissue expander proposed herein, is made of a biocompatible material, for being implanted subcutaneously, and comprises an expandable pouch with a tube integrally attached thereto? a remote valve member having a chamber, with a tube integrally attached thereto, said member comprising first and second opposed parts, the first part being made of a self-sealing material 5 at least one connector tube for interconnecting the tubes of the said expandable pouch and of the valve member, such that the needle of a hypodermic syringe introduced into the valve member, through the first part thereof, is enabled to inject saline into the chamber of the valve member, whence the saline passes through the connector tube into the pouch, for inflating the same, characterised in that the other part of the said valve member is sufficiently tough to serve as an impenetrable non-metallie needle stopper; and further characterised in that the portion of the pouch intended to be in contact with tissue to be expanded, is more elastic than the remaining portion thereof, to thus provide differential expansion of the pouch. This invention will now be further described with reference to the accompanying drawings, which i1lustrate, by way of exemplification, and not by way of limitation, two of possible embodiments of the proposed tissue expander, in Figs. 1 and 2 thereof. The tissue expander is made of a biocompatible material, such as, si 1icone rubber for being implanted subcutaneously. To a shapeless expandable corresponding to a hemisphere and a rectangular shel1 respectively illustrated in Figs. 1 and 2. In the uninflated state the pouches are shapeless and can be flattened, manually, as, for instance when they have to be implanted subcutaneously. To a remote valve member V is integrally attached a tube T2. The said member has first and second opposed parts, A and B, the first part A being shown as dome-shaped (in the embodiment illustrated in Fig.1) and made of a self-sealing material, to enable the needle of a hypodermic syringe to pierce the said dome, for injecting saline into the said member and to be drawn out, thereafter, without leaks developing at the entry point of the needle. Instead of saline other fluids which are compatible for them purpose may be used. The term "saline" in this specification has to be interpreted accordingly. At least one polyacetal connector tube T interconnects the tubes Ti and T2, whereby the saline injected into the valve member is enabled to pass through the connector tube into the pouch P, for inflating the same. One of the characteristic features of this invention is that the other part B of the said valve member is sufficiently tough to serve as an impenetrable needle stopper T. In other words, once the needle of the hypodermic syringe pierces the dome-shaped part A of the valve member and enters the chamber D thereof, the said needle is incapable of further piercing and passing through the part B of the valve member and injuring the patient. Another characteristic feature of this invention is that the portion E of the pouch intended to be in contact with tissue, to be expanded, is more elastic than the remaining portion F thereof, to thus provide di fferential expansion of the pouch. This feature results in laying greater emphasis on expansion taking place against the target tissue rather than on expansion taking place against non-target tissue. Preferably, the expandable pouch is made of silicone rubber- The first part A of the said valve member (exemplified as a dome in the drawings) is preferably made of reinforced si 1icone material and the second part B of said valve member is made of polypropylene. The terms and expressions in this specification are of description and not of 1 imitation, there being no intention of excluding any equivalents of the features i1lustrated and described, but various other embodiments of the tissue expander proposed herein are possible without departing from the scope and ambit of this invention. We Claim: 1. A tissue expander made of a biocompatible material, for being implanted subcutaneously, comprising an expandable pouch with a tube integrally attached thereto; a remote valve member having a chamber, with a tube integrally attached thereto, said member comprising first and second opposed parts, the first part being made of a self-sealing material; at least one non-metallic connector tube for interconnecting the tubes of the said expandable pouch and of the valve member, such that the needle of a hypodermic syringe introduced into the valve member, through the first part thereof, is enabled to inject saline into the chamber of the valve member, whence the saline passes through the connector tube into the pouch, for inflating the same, characterised in that the other part of the said valve member is sufficiently tough to serve as an impenetrable non-metallie needle stopper; and further characterised in that the portion of the pouch intended to be in contact with tissue to be expanded, is more elastic than the remaining portion thereof, to thus provide differential expansion of the pouch. \^^,Z; A tissue expander as claimed in Claim 1 wherein the expandable pouch is made of silicone rubber. 3. A tissue expander as claimed in Claim 1 or Claim 2 wherein the first part of the said valve member is dome shaped. 4. A tissue expander as claimed in any one of the preceding Claims wherein the first part of the said valve member is made of reinforced silicone material and the second part of said valve member is made of polypropylene. 5. A tissue expander as claimed in any one of the preceding Claims wherein the connector tube is a polyacetal tube. 6. A tissue expander substantially as herein described with reference to, and as illustrated in, the accompanying drawings.

Documents:

0190-mas-2002 abstract granted.pdf

0190-mas-2002 claims granted.pdf

0190-mas-2002 description(complete) granted.pdf

0190-mas-2002 drawings gratned.pdf

190-mas-2002-abstract.pdf

190-mas-2002-claims.pdf

190-mas-2002-correspondnece-others.pdf

190-mas-2002-correspondnece-po.pdf

190-mas-2002-description(complete).pdf

190-mas-2002-drawings.pdf

190-mas-2002-form 1.pdf

190-mas-2002-form 26.pdf