What is Expaniderm

An introduction to our intelligent expander

The first in a new class

Expaniderm is the first in a new class of implantable soft tissue expanders, offering control, reliability and convenience. Suitable for a wide range of applications in equine and canine surgery.

  • New generation of expander - Self expanding – no injection port
  • Made with a hydrogel core and medical grade silicone coat
  • Absorbs tissue fluid to achieve a slow constant rate of expansion
  • Expands over 2 week period
  • Controlled direction of swelling – allows precision and control
  • No need for repeated visits for filling injection so reduces risk associated with repeated injection
  • Slow constant expansion which reduces discomfort associated with expansion
  • Produces good quality, highly vascular skin
  • Flexibility of size and position so skin is produced where you need it

Three phases of expansion

The science behind Expaniderm presents a significant improvement over existing hydrogel expanders. The device typically displays a triphasic swelling profile in vivo (see graph below).

Phase I represents the biodegradable ‘time switch’ which delays the onset of swelling following implantation for a period of typically two weeks (as dictated by the surgeon).

In Phase II the rate of osmotic expansion is carefully controlled either by an integral polymer scaffold or an external semipermeable membrane thus preventing the undesirable effects of excessive expansion which include pain and potential tissue necrosis.

In Phase III the final degree of swelling achieved can be precisely controlled (up to 1500% if necessary) and is determined by the hydrogel formulation used. The device is entirely inert and will remain quiescent during Phase III until surgically removed in order to perform the definitive reconstruction.


Tissue expansion is commonly used in human reconstructive surgery to grow extra skin through controlled mechanical overstretch.

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