I am curious about the advancements in stem cells in regards to PE. However, it will be many years before such a treatment (assuming it works) would be available to the public with research to support it. I think it is probably the best shot we have in terms of a non-invasive procedure, but once again given the amount of diseases/disorders that could benefit from stems cells and the political tape around embryonic stem cells PE is going to be the last potential use being investigated.
As for Dr. Runel, the man seems like a quack. Check out his website and see how it is marketed, his videos make him look like a complete nut. He advertised his procedure on PEgym and other forums, but in all cases when people started to question him he left and never came back. He has no research on his procedure either, so if you decide to do it you will be the experiment and you will pay him $1900 to be a guinea pig.
I’m not sure I have too much faith in PRP therapy for enlargement. The growth factors that are extracted from the blood to be used in PRP were and are now even more so present in the fat transfer technique used for girth as at least one surgeon I believe is extracting these growth factors and reinforcing the fat transfer with them. The fat transfer method naturally has these growth factors when the fat is extracted, so even before reinforcing these growth factors were present. The fat transfer procedure saw and still continues to have absorption problems of the fat and no real evidence of growth despite those growth factors being present.