Want a reduction, 34D to 34B. Previous breast lift, superior pedical, 7 yrs ago using Bio-A internal Mesh. (photos)

Yes, you can certainly undergo repeat breast lifting (or reduction) surgery safely. I think that you have a good understanding of some of the concerns.One of the concerns when repeating breast reduction surgery is related to blood flow to the remaining breast tissue; is important to perform the operation in such a fashion that the blood flow to the nipple/areola/breast tissue is not compromised. The part of the tissue that is left in place after breast reduction surgery is called the “pedicle"; this segment of tissue is responsible for delivering the blood supply to the nipple/areola/ breast tissue. If the pedicle (that was used during the previous breast reduction procedure) is cut then the blood flow to tissues may be compromised leading to serious complications such as tissue necrosis etc.
It will be helpful for you to find the previous surgeon's operative report prior to the redo surgery, if you are working with a different surgeon.
Make sure that you communicate your size goals carefully; in my practice, I encourage patients NOT to use cups sizes as references;  the use of visual aids such as photographs are much more helpful.
I hope this helps.  Best wishes.

Obviously
your previous surgery was unsuccessful and your breasts are too low on the
chest wall.  Passive mesh techniques usually
fail.  I recommend The Bellesoma Method
to reshape your breast tissue creating upper pole fullness without implants,
elevate them higher on the chest wall and more medial to increase your
cleavage.  Vertical scars are avoided,
nipple sensation and the ability to breast feed are maintained, if not injured
during your previous surgery.  Best Wishes,Gary Horndeski, M.D.

A breast lift with some reduction would be safe to do, maintaining the superior pedicle intact and reducing the lateral pole.