There are a variety of implant materials that can be used for both standard and custom facial implants. These include solid silicone, porous polyethylene (Medpor, Omnivore and Supor), PEEK and titanium. While surgeons may often tout one material as being superior to another this is simply not accurate. All of the mentioned implant materials can be effective but they each have their own advantages and disadvantages. Understanding the differences between them in their biologic and handling characteristics allows the surgeon and patient to make an educated facial implant material choice.
One the commonly used materials, porous polyethylene, goes by a variety of commercial names. ((Medpor, Omnivore and Supor) Its most distinguishing characteristic is its permeable material surface which permits some degree of tissue ingrowth. While tissue ingrowth sounds like an appealing implant feature it is so if one never has to have any secondary implant surgery to replace and/or modify the implant. But at a near 40% long term revision rate for all facial implants, regardless of material composition, that very tissue ingrowth can be a disadvantage. The vigorous adherence of the soft tissues to the implant have given it a valid reputation of being difficult to remove or revise. So much some say it is impossible to do so.
Havin removed many porous polyethylene implants I can say it is challenging but it is always possible to do. There are a variety of learned techniques in elevating and removing this type of facial implant and in most cases this is what is done. But there are instances where, rather than the removal, there is a need for modifying or reducing a portion of the implant but still keeping it in place.
There are limited indications for in situ implant modification due to the constraints of surgical access and what dimensional changes to the implant that need to be done. While porous polyethylene out of the box is like firm plastic, once implanted due to tissue ingrowth, becomes more malleable/modifiable. There are three tools that can be used to modify the implants, reciprocating saw, scalpel blade and large-toothed rasp. The reciprocating saw and scalpel blade can cut through the material. Between the two the scalpel blade makes a cleaner cut but the length its cut and reach are less than that of the saw. The rasp is used to smooth out the cut lines much like rasping or filing down bone surfaces.
For minor modifications of porous polyethylene facial implants in situ reductions are possible. Whether it can be successful depends on having direct linear access to the area of the implant that needs to be reduced.
Dr. Barry Eppley
World-Renowned Plastic Surgeon