Double chamber tissue expander

Abstract

A tissue expansion device for subcutaneous implantation in a patient consisting of an implantable expandable bladder prepared from a porous material which defines an infusion solution chamber, and an inner bladder disposed within the outer bladder prepared from an expandable non-porous material which defines an expansion solution chamber. Liquid transport means are provided for introducing and removing an infusion solution into and out of the infusion solution chamber, and fluid transport means are provided for introducing and removing an expansion fluid into and out of the expansion solution chamber. Following implantation of the tissue expansion device subcutaneously, expansion fluid can be introduced into the expansion chamber by use of the fluid transport means causing the inner bladder to expand. The expansion of the inner bladder exerts pressure on the infusion chamber, which contains infusion solution introduced through the liquid transport means. The infusion solution passes through the pores of the expandable porous material into the tissue surrounding and contacting the expansile porous wall of the implanted tissue expansion device. The outer bladder also expands, due primarily to expansion of the inner bladder and to introduction of infusion solution. The infusion solution can contain agents to facilitate the expansion process, such as hyaluronidase, lidocaine, epidermal growth factor, or dexamethasone, or any combination thereof.