Nerve Re-Sensation

As I write this blog in 2021, we have been doing nerve grafting for re-sensation of breasts after nipple sparing mastectomy for the whole year. I’d love to share with you what our expectations were, what we learned, and our conclusions so far. 

It is still in the early process for the relatively new surgery.  I hope this article helps you make the best decision for you.

During mastectomy, the nerves in the breast are cut, resulting in a permanent loss of breast sensation. To solve this issue, we perform nerve grafting to reconnect the nerves, allowing for breast sensation. This is performed at the same time as the breast reconstruction. 

First, our expectations, as surgeons, were that it would probably not work great. Yes, our expectations were that low! The graft connects a cut nerve where it enters the breast to another cut nerve on the back of the skin. This seemed a little like plugging in a single Christmas tree light to me, in theory. To be honest, what talked me into it was my friend, Ann Peled, and her husband Ziv, and her personal experience with breast cancer. 

She was enthusiastic about doing the grafts, and her husband just happens to be a peripheral nerve surgeon, so they made a great team to be the first adopters. In addition, teams were already doing the graft with DIEP flaps, so it was not completely outside the norm. The unique thing with the implant reconstruction was that the surgeon has to find not only the cut nerve root, as the breast is removed from the chest wall, but also find a sensory nerve on the mastectomy flap to plug it in to. This connection, by the way, is called an “anastomosis”, for you medical geeks. 

This is a great idea in theory, but in reality, we wondered if it would work. Before we actually did the first case, we looked around for nerves on every patient. One would think that a nerve would be like a branching tree, where the nerve at the very end would be so small that there would be no point in connecting it to the tip and just getting a tiny bit of sensation. It could be like connecting a trunk to one leaf! What we found surprised us; the nerve spread out, and then coalesced back together again to make 2-3mm bundles around the areola. It was easiest to find just outside the thicker tissue just under the nipple, and reliable. The other great news was that there was really no downside, aside from cost. Usually, the nerve is NOT grafted or attached to anything, and this is actually MORE risky, as there is supposedly a chance this cut, loose nerve could form a neuroma under the implant and hurt. A neuroma is a wad of sensitive nerve tissue that goes nowhere. Let me say that we do not really ever have problems with neuromas, although I have seen them before with others. Theoretically, if the nerve has somewhere to regrow to, it will travel down the nerve graft like a live wire and reconnect to the nerve on the skin and voila! Sensation. We decided to try our first graft. On our next five patients with cancer on one side undergoing bilateral mastectomy, we only performed the nerve reconstruction on the prophylactic side, in case there could be disruption of the breast tissue containing cancer.

The first grafts went very well. Every patient had nerves on both ends, and we got better and better at finding the proximal and distal nerves. The proximal nerves were especially exciting, as sometimes we find more than one nerve, rarely located where they are supposed to be. The nerve is best found together with the mastectomy surgeon, as that surgeon ensures that there is no chance of dissecting or spreading tumor. Dr. Heather Richardson also keeps finding nerves for us even after we dissect the main branches; she has an eagle eye for nerve roots that we can combine into our repairs. There are also tricks to avoid damaging the nerve as the implant reconstruction is performed. The entire pocket for the implant really needs to be sewn in first, and the appearance checked with the patient seated upright in the OR, so the aesthetic decisions are already made. The implant is then removed, the anastomosis (remember from above!) is performed, and then the final implant is placed back into the pocket using a Keller funnel. We have had no reactions to the nerve graft or any problems so far, even with over 50 grafts between myself and Dr. Killeen. The graft may add 15 or 30 minutes to the case, but in the bilateral mastectomy we can usually complete one side while the mastectomy is still happening, it adds little time under anesthesia. We met with Axogen and other early adopters for the re-sensation with DTI. A big shout out to Axogen for putting this together, as we got advice from surgeons who work with peripheral nerves all the time, many of them doing nerve grafts, hand surgery, and repairing cut nerves regularly. If you have extra nerves in the dissection, add them in an “end to side” connection to the existing nerves. Recut the nerves sharply distally and avoid using a nerve end with a cautery burn. Bundle the nerves if the size match is adequate. 

The other exciting news is our early results. Every patient of our first five has better sensation on the nerve graft side than the non-grafted side. No one has normal sensation compared to their pre-op sensation yet. We don’t know if that will come in time, or it will never be the same. Right now, my best guess is that it will never be the same, but it is better than nothing. Sometimes, numb is painful, and numb is strange, and numb is distracting from life. And most importantly, once you are done with breast cancer, you don’t want to think about your breast cancer, be distracted by your reconstruction, or have pain. We thought we really had breast cancer reconstruction “down” before this new advance, but now we can safely say, it’s even better.