In my opinion, the purpose of the drain is when you create what we call in plastic surgery a flat, where tissue is separated over a large surface area from its base. Here, until the flap can it here to the base there is potential for liquid to develop in that interface. With liposuction, there is not really one big space but many little tiny spaces were fluid can collect. In this situation, the body will resorb the extra fluid. One of the new techniques is to use a tissue glue to fill in the space between this flap and the base to obviate the need for a drain. I’ve used this principle for many years in facelifts and now a new glue called tissue glue is available for tummy talks. Good luck.