I can see why you would be anxious. I think your breast reduction is very challenging not only because of the magnitude of the reduction, but also the distance that the nipple must be moved. The longer the distance and the larger the volume reduction the more risk of limiting blood flow to the nipple. While it is certainly possible that your surgery can go well depending on the execution of the surgery, the technique chosen, and other risk factors you might have (i.e. smoking, diabetes, heart disease, blood disorders, etc.) other options and fallback treatment should be discussed.
One option would be to do your surgery in two stages with the first being liposuction if the breast has a large percentage of fat rather than gland. If it is predominantly glandular tissue, this is not possible. Your surgeon can then do a smaller reduction at a second surgery.
Anticipation of doing a nipple graft, or going straight to a nipple graft technique should be in the back of your surgeon's mind in case the nipple looks compromised at surgery.
Finally, I would look into the availabiltiy of hyperbaric oxygen therapy post-op if the nipple viability looks questionable. This can often nurse the breast tissues, and nipple in specific, through a period of uncertainty.
Good luck.
