A tummy tuck associated with liposuction, either well before or at the time of the tummy tuck or abdominoplasty, does not increase the risk of complications for tummy tuck assuming that you are a good surgical candidate.  Many patients want a tummy tuck but they are over a BMI of 30. The surgical literature on tummy tuck is very clear that there is a high complication rate with a high BMI.
If you seek out a surgeon who is a member of the American Society for Aesthetic Plastic Surgery you reduce your risks as well since those individuals are specifically trained in tummy tuck surgery and committed to minimizing risks in cosmetic surgery.
A 24 hour rapid recovery, no drain tummy tuck is another way to reduce the many risks of a surgery like an abdominoplasty or tummy tuck.