Generally, it is advisable not to be very aggressive (the so called “mega-liposuction”) to avoid complications.
However, different areas such as abdomen and thigh or buttock are not done in one session. What is important from a safety angle is the amount of blood and fat removed.
Large or Mega liposuctions are associated with an increased risk. It is important to keep in mind that in any cosmetic procedure including liposuction, final safe and satisfactory result is far more important than quick results.