Fat transfer can be done with needle size incisions. Swelling after fat transfer can last about a week, however, there usually isn't significant bruising. If there is, that can also about the same time.
Swelling and bruising vary with the technique, amount of fat transfered, and location. The eye lids will bruise more than the cheeks. A good technique using medication to constrict blood vessels, Micro injection with blunt canula, Very small canula, and most important is the proper preperation of fat prior to injection