The use of synthetic implant materials in plastic surgery is often necessary to obtain the desired surgical result. Whether it is a silicone breast implant or a hyaluronic acid injectable filler, the placement of foreign materials is common in plastic surgery. When considering an implantable plastic surgery procedure, patients may inquire as to whether their body may reject the implant.This common query reflects an understandable misunderstanding of how the body reacts to implanted foreign materials and what type of complications can develop as a result.

In reality, the rejection of an implanted synthetic material (that has been evaluated and approved for human implantation by the FDA), in the most scientific sense, does not happen. A true rejection reaction in humans is an autoimmune response to an 'implant' that is composed of live or organic material. Therefore, you will develop a rejection or autoimmune reaction, for example, in any type of organ transplant which is from other human or animal origins. Your body's cells mount a massive response to what it recognizes as foreign or an invading organic source. The body is quite smart and protective as this type of response is necessary for survival.

Inorganic materials, such as synthetic implants, do not elicit a true autoimmune or rejection response. These are not live materials and were never composed of living organic materials. Therefore, an allergic response does not happen. They will never integrate or become part of your body's tissues, but they can be tolerated by occupying a walled-off space. Synthetic implants, while not causing allergic responses, can cause a different set of problems which patients mistakenly interpret as 'rejection'. Synthetic implants can get infected, exposed, or migrate, all of which are complications of the surgical implantation process not due to rejection. If bacteria inadvertently get on the surface of the implant, an infection can later develop.Most implant infections occur within weeks of the surgery as it takes time for the bacteria to multiply and become evident. Synthetic implants can migrate or move from their location where they were surgically placed if the implant material is very smooth or the tissue pocket into which it is placed is very big. This potential migration can be eliminated if the implant is secured into its desired location by some method such as sutures or metal screws. Implant exposure can result from migration of the implant, getting close to the original incision through which it is placed. Implant exposure occurs because there is not enough good quality tissue covering it or the implant is putting too much pressure on the surrounding tissue, resulting in poor healing and potential tissue breakdown and implant exposure.

The typical synthetic implant complications are often misinterpreted as rejection of the implant. In reality, the patient's body has little to do with the development of these complications. They are more a function of surgical technique and not due to a patient's immune response to them. The risk of these potential implant complications can be reduced by pre-surgery antibiotics, a properly sized implant that does not stress the surrounding tissues, and careful surgical implantation technique.