I generally counsel my patients that a cleavage can be deepened (and therefore enhanced), but it cannot be narrowed. The space between your breasts is determined by your breast tissue, muscles, and breast bone. There is a limit to how close breast implants can or should be placed in order to have an overall good result. E.g. if they are too close and the nipples are more to the outside, it leads to a very unnatural appearance. This is more easily demonstrated during the course of a physical exam. I would suggest a formal consultation with a board-certified plastic surgeon so your specific concerns can be gone over in detail, a physical exam be performed, and individualized recommendations be made. I hope this is helpful.