Huh. Well, you know, every case is different and doctors frequently differ in their recommendations. Sometimes it just depends on how familiar they are with a certain procedure. There are some slight differences in how they do Nissens for scleroderma patients; I think it is usually a partial rather than a full (or the other way around). And a huge factor in its success is the experience of the surgeon; it is the most important consideration of all. Some centers specialize in redoing Nissens that other surgeons messed up, which is a rather scary thought. I would not ever want anyone messing up my throat, thank you very much.
An interesting thing I discovered, when doing research for a surgery I had a few years ago, was that the majority of surgeons lie about their experience, and always in favor of over-estimating the number of particular surgeries they have done, and possibly even their success rate.
So if by any chance you or your doctors are going to further consider it, you would put the odds more highly in your favor of a successful outcome by doing significant research on the best hospital for it, as well as the best surgeon at that hospital -- and then consult with that surgeon (and only that surgeon, and make sure they will not just supervise a resident or another surgeon, as they often end up in teaching positions). And never take the surgeon's word regarding their track record; seek out the facts.
In the course of my research on that surgery, one surgeon -- who was highly recommended in our area -- told me that he did the minimally-invasive sort of surgery that I was hoping for. But when I asked him how long the scar would be, he said 8 inches; whereas the scar for the real minimally-invasive surgery is only 1 inch. I asked him how long I would be in the hospital and he said, oh, five to seven days or so. Whereas the real minimally-invasive version only required an hour or two in recovery! So it paid for me to realize that I was dealing with a surgical scoundrel, probably a well-intentioned one, but a scoundrel anyway...at a very major medical center, no less. I know its hard to question our doctors, not to mention our surgeons, but it is our very health and often longevity that is at stake.
If an experienced, successful Nissen surgeon doesn't want to take your case on, then you know for an absolute fact that it's a bad idea! Also if they are not acutely aware of scleroderma, and potential complications, that would be another poor indicator.
Some things just simply are out of the ballpark for us. There are certainly some complications that make us bad candidates for various surgeries and treatments. But sometimes we never know for certain until we push the issue to the max, and then live with whatever the results are. But at least we have the personal satisfaction of knowing that we did indeed push it to the max. It's not our fault when we run into brick walls but we can regret not even trying.
Anyway, the Nissen is the only avenue forward that I'm aware of, that would improve your possible lung transplant odds, down the road.