Have any of you had problems with the saline wanting to sit at the top of the expander?

Unfortunately I was unable to make it completely through reconstruction, as my plastic surgeon found scar tissue in my muscle wall that tested positive for cancer.

I have found that my personal experience with tissue expanders (used to stretch out the skin after a mastectomy and prior to implants being placed) has been with the expander shifting and not stretching out the correct area of my breast.  when this originally happened I was asked to massage (push) the expander downwards.  I was also told that when the time came to swap out the expanders he would make "pockets" so that the implants would stay in the correct position.

Prior to chosing implants I looked at lots of pictures of reconstructed breast using tram flap procedures, and was even told once that the success rate of a flap varied greatly upon the tissue used to reconstruct.  It could fail easily.  That is why I chose implants, and with a good doctor you will get great looking breast (not all implants look like Pam Anderson.)

I'm sure yours will be fine.  Discuss your concerns with your doctor, that's what he's there for.  Hope I was able to help some!