Solutions for Loose Skin on Abdomen?

Unfortunately, at this time there are no non-surgical options to tighten loose abdominal skin.  There are some lasers that you can try that will temporarily help slight looseness but if you have significant loose skin, an abdominoplasty is what you need.  If you don't need abdominal muscle repair, you may be able to have a skin only tummy tuck or if you are a candidate, a mini-tummy tuck.  It's difficult to say what would be the best option for you without photos or a physical exam, so make sure you consult with a Board Certified Plastic Surgeon to see what the best options are for you.  Make sure that you disclose your lymphedema to your surgeon to make sure you have the appropriate tests prior to surgery as it's always best to be safe than have complications later that could've been avoided.

There are no good non-invasive was to tighten loose abdominal skin - skin laxity is a mechanical problem, and the solution is surgical - you need a tummy tuck. I've had experience with laser liposuction, ultra-sound based technologies and other non-invasive devices - they don't work for moderate and severe skin laxity.

Without pictures, I cannot say if tummy tuck is right for you.  I also need more information to know  whether it is safe to do the surgery.  Specifically, what is the cause of your current lymphedema?