how possible

I just cannot understand one thing. When clamping there is increased blood pressure above clamp that expands tunica and a lot of guys reported good gains in girth. I can understand that. But how it is possible to gain girth in the are where the clamp is located itself or below it? There is no expansion there. I guess it could be some chemicals released when clamping that stimulates penis growth under all areas. Any ideas how to explain this?

It could be that it balance itself out someway. When you gain weight in the upper part of your body, the lower part can carry it without extra exercise. Could be that the same applies with girth.