After a 140 lb. weight loss (Congratulations, regardless of the method of loss!) your loose skin almost certainly extends around the entire abdomen, hip roll, lateral thigh, and buttock regions. You have already had a tummy tuck, and at the very end of your incisions on either side you have all the previously-existing loose skin remaining. These areas are properly called the flanks (literally, the area of tissue between the lowest ribs and the hips), hip rolls, or "love handles." How much loose skin is the issue I am concerned about for you.
When a small amount of residual tissue protrudes after a tummy tuck, these are called "dog ears," and excision with a somewhat longer scar can smooth the protrusion nicely. When more loose skin exists, a flank excision is absolutely appropriate. But after the amount of weight loss you describe, your more significant amount of loose skin may be better treated by a "buttock lift," "posterior lift," or what I would call a "completion belt lift." I call it that because I excise additional skin all the way to the upper point of the central gluteal crease, not just an ellipse of skin and fat over your flanks.
This is exactly what I do when I combine a tummy tuck and posterior lift into one operation called a circumferential belt lift, lower body lift, or belt lipectomy. But you have had the tummy tuck; you now likely need "completion" of what would be your belt lift. Flank excision alone may not be enough for your best result, and if this is done instead of a more aggressive excision, you may require yet another operation (removal of dog ears from your dog ears?)
Of course, your PS has the benefit of direct examination, and your excision may require more, or less, as your degree of skin laxity requires. Don't be shy asking if you need or would benefit from excision of an entire band of tissue across your buttocks, lateral thigh, and hip roll (flank) areas rather than just an ellipse over each flank. Of course, the latter may be possible under local anesthesia, whereas the former will require a bigger operation, full anesthesia, and possibly drains--BUT, may well yield a substantially better result!
As other have stated, unless you have an excessively tight closure, too much activity, or risk factors such as diabetes or tobacco (nicotine) use, you have no higher potential for wound separation than anyone (regardless of procedure.) This likelihood is quite low, but never zero. Best wishes! Dr. Tholen