A new type of implant which does not contain silicone gel is being used for breast reconstruction following cancer surgery. The device, called Trilucent, contains soybean oils and fats. It has been developed to avoid the need for silicone filled implants since these are alleged to be linked to immune and connective tissue disorders.

The silicone implant story is highly controversial. US-based silicone implant manufacturers do not accept the link with health problems. But in 1993 they set up a ?2.6 billion compensation fund for women who claim that they had been damaged by leaking silicone implants.

In the UK, the Department of Health’s expert advisory committee concluded that there was no evidence of an increased risk of immune disorders in women with silicone gel breast implants. But some British surgeons try to avoid using them because of the controversy.

Until recently, the only alternative has been implants filled with salt solution (saline). But, as Andrew Baildam, senior lecturer in surgery at the University Hospital of South Manchester, explains, saline implants are not cosmetically as good as silicone implants and they can deflate.

The advantage of the new implant is that the fats it contains have proved safe when used in other medical procedures, such as in intravenous nutrition and anaesthetics.

We know that if these implants do leak it is unlikely that there will be immune reactions against the contents, he says.

The new implants also feel more realistic than saline implants, though probably not as good as silicone devices, says Mr Baildam.

The disadvantage of the new implants is that we have been using them for less than a year so we don’t know if there are long term effects, he adds.

However, he points out that a special microchip tag placed in every implant means they can be traced after long periods, and this should make it easier to pick up any problems.

Breast reconstruction can be carried out at any stage after cancer surgery and it remains uncertain whether results are better if it is done at the same time as mastectomy or left until later. Some surgeons prefer to wait until adjuvant treatment, such as radio- or chemotherapy, is complete, but many women may prefer to have reconstruction immediately.