Together with a surgical team at University of Oxford we are developing novel tissue expanders for use in reconstructive surgery, with the ability to expand in only one direction. Tissue expanders are essential in providing extra soft tissue for a wide range of reconstructive techniques. However they have a number of disadvantages. Inflatable silicone balloons are bulky and unsuitable for small delicate areas. They must be regularly inflated by means of a filling port, which is both time demanding and painful for the patient and there is a risk that the device may leak. Self-inflating hydrogel expanders have heralded a significant advance. However they expand isotropically at an uncontrolled rate and have limited expansion limits. Therefore their use in specific applications such as cleft palate surgery, syndactyly (fused digit) release and facial reconstruction has been limited.
We are developing a novel, anisotropic, self-inflating, hydrogel tissue expander using hydrogels that can be machined or shaped appropriately for the desired application. By carefully controlling the hydrogel composition it is possible to accurately tailor the ultimate expansion ratio and the expansion rate within a wide range. The device may be further enhanced by the incorporation of drugs, growth factors or radio-opacifiers in order to tailor the device to specific clinical indications. The technical feasibility and anisotropic efficacy of the device is being determined by means of a preclinical study.