What is an Abdominal "6-pack" Implant?

I am guessing but this may be a play on words to appeal to the marketing of the procedure. It is more likely a reflection of a modified lipoetching procedure possibly with lipoiinjection not unlike the Brazilian Butt Lift.

That is a direct quote from a chat forum where lay persons talked about the horrendous appearance of 6 pack implants. I could not personally find the before and after photos and, in fact, had never heard of 6 pack implants until your question. As you can see, my colleague board certified plastic surgeons are NOT proponents, and I would venture to say that most of them had never heard of it either. As you well know, many structures can be enhanced with implants, including the breasts, buttocks and calves. The difference between an implant placed in the breast, chest, buttock or calf and your "6 pack implant" is that ALL of the other implants are placed on a solid structure platform, the chest wall, the buttock muscles, the calf muscles, even though they are covered by muscle as well. An abdominal implant placed under the rectus (abdominal) muscles would have only intestines and visceral organs as its platform, none of which would allow the implant to be supported and visible from the outside.