There are also indications for the using liposuction in the neck, either alone or in conjuction with a traditional necklift. Breast augmentation is a permanent enlargement. If you are asking how long do the implants last, then the answer is unknown. Nursing, mammograms and breast exams are all still posiible after breast augmentation. There is no causal link between silicone gel implants and autoimmune diseases in today's literature.
Capsular contracture is a variable response to implants and multifactorial.
Good surgical technique and massage avoid encapsulation. Liposuction permanently removes the fat cells. They do not return. This is not to say that you now have a blank check to eat, but rather that with a healthy diet and exercise, you should not see a return in this area. Your propensity to store fat in the area remains unchanged and the remaining cell may pick up the work and store fat there if you eat too much.