I know this will not answer your question, but it may give you some strength. There are many questions about our bodies which do not have either easy or plain answers. In these questions, one must do the best you can with what you have, and commit to living full blast with what you have left over. I have several stenoses and cancers and a bunch of other stuff which makes scrambles out of diagnoses and therapies. But I learned a simple truth while milking cows. When you grab and squeeze, you live with what comes out. Some of my therapies have gone backwards quickly. But the only ones I regret are the ones performed by medicos who just wanted the money, and I was chicken to say "No!" So grab and squeeze, and celebrate that you have lived long enough to know you should have tried something different! oldkarl