The results of liposuction will be permanent as long as you maintain you post-operative weight. Even if you gain a few pounds you might find that the weight is distributed more evenly instead of gathering in your previous trouble areas.
It may take several months for the swelling to fully subside, delaying the appearance of your new, slimmer figure. The healing process is gradual so you should expect to wait awhile before fully enjoying your new results.
You will return to your plastic surgeon's office for follow-up care at designated intervals to evaluate your progress.