Find a new surgeon
I would venture that is is almost never required to remove the nipple. 15 cm is not that long. You have run up against a very old fashioned surgeon, or one that was poorly trained. Find a new surgeon.
Free nipple graft
I almost never perform a free nipple graft, and my inclination to perform a free nipple graft will go up when the distance from the fold to the nipple is greater than 20 cms. I have treated many large breasted women using a standard inferior pedicle.
Do I have to get nipples removed for breast reduction?
Thank you for your question. In my practice, I've never had to detach the nipple as part of a breast reduction. This includes many breast reductions performed with sizes much larger than yours. It's usually left as a last resort option if tissue viability is potentially compromised at the end of a case. Be sure to consult with several experienced board certified plastic surgeons. Good luck.
Free nipple grafting
Nipple removal and grafting is only used in patients with an extremely long nipple to inframammary-mammary crease distance. In order to appropriately position the nipple, it must be removed and replaced as a graft. Nipple necrosis and sloughing is a risk in either type of procedure. Discuss your concerns with your surgeon so that you can have a better understanding of the procedure, the reasons which might necessitate it and the risks.
Photos are essential for a question like this. I will say that free nipple grafting today is extremely unusual but there is still a place for it. Even if it is done the complication you're describing can happen book is extremely unusual.