There is a delicate network of thin filamental lymphatic fibers on top of the rectus abdominis sheath. These lymphatic fibers drain into the lymph nodes down in the groin. The umbilical line divides the drainage of these fibers. Above the umbilicus, they drain upward to the axillary lymph nodes. Below the umbilicus, they drain down into the inguinal nodes.
It is my experience that traditional liposuction rarely goes down to these fibers, and therefore almost never causes a seroma. Scars left by traditional liposuction are intermittently placed, and therefore do not increase the chance of a seroma in a post liposuction abdominoplasty.
Unfortunately, the newer forms of liposuction, Vaser, Laser, Slim, Smooth, etc. create a much larger field-like destruction of these filmy lymphatics, and therefore abdominoplasties after these types of liposuctions very often are fraught with recurrent seromas.
Other forms of abdominal wall interventions such as C-sections and hysterectomies done from a bikini line incision (pfannenstiel incision) tend to increase the likelihood of a seroma. Surgeons performing these operations and assistants pulling on retractors are often more concerned with the intra-abdominal surgery than with protecting the lymphatics on the rectus sheath. Therefore, abdominoplasties after gynecologic bikini line incisions have a much greater chance of recurrent seromas due to the destruction of these necessary and delicate lymphatics.
Recurrent seromas in a situation where the channels to take up excess fluid have been destroyed are very difficult to resolve. I find recurrent drainage in this situation to be of minimal value. The seromacath left in for 3 or 4 days with intermitten installation of a sclerosing agent has a much better chance of obliterating these pockets of fluid since few, if any, lymph drainage channels remain.