well, we've come to body worlds in london to come to dr dan marsh, who is a plastic surgeon.kindly come out of surgery for us today, to bring along some implants and show us about them. just tell me exactly what they are. an implant is basically made of silicon, so you've got a silicon shell, inside this you've got a sticky silicon gel — it's fairly gooey. so if you were to cut the implant in half, all the gel would sit where it stays. a breast implant is usually placed through an incision under the breast. the implant can go either in front of the muscle or behind the pec muscle. people often think the implant goes into the breast — it actually goes behind the breast, so all of your breast tissue sits in front of the implant. so how is it that something like that could potentially cause breast implant illness? i think the honest answer to that is we don't really know what causes it. the jury is still out on whether breast implant illness is a thing, it exists. we think that it's the body's reaction to the silicon. but silicon is present and lots of medical devices — cardiac