With hair loss being a progressive condition, I don't think anyone can go into surgery with the idea that they will never need another surgery. Sometimes for the best long term result more than one surgery will be necessary. Other times, over time, the hair loss can progress to the point that another surgery may be needed or desired. I think any good surgeon transplants hair to mix in with the existing hair so that if there is some thinning of the existing hair it still looks natural. But if existing hair continues to thin and progress, there would be no way to address that in one surgery. The surgery I had may stand alone and I may never need another one. That said, based on my consultations, I went into it knowing that I might need or want more. My doctor planned for that and I have plenty of donor left to handle any needs I might have in the future. So, planning is the key and doctors should plan with the patient for the long term. If you use up all or most of your available donor in one pass, that is a very risky proposition in my opinion. Finally, the younger you are when you have a hair transplant, the more likely it is that you will need more than one procedure. So, I do think that each surgery should look nice and natural with significant improvement in the patient's eyes, but I am not sure that any surgery can necessarily truly stand alone for the long term.....it might, but no guarantees.