I have plenty of family issues myself... so I really don't know if any advice I give is any good.
There's only so much you can do to be close to someone without them reciprocating. I know that I personally felt, and still feel, an obligation to keep trying to fulfill the idea I have of what "family" is. I'm estranged from my father, but for different reasons, it seems, than you and your brother are. Even so, I call him every few months to see how he's doing, offer to have lunch with him, talk a bit... it usually gets cancelled by him. Honestly, it gets a little emotionally tiring. So, I have the feeling I can relate to your situation.
So, all that said, I'm glad you called your brother, I think it was the right thing to do. When, and in all honestly, possibly if, he's willing to reciprocate, he'll make the motions. I have the feeling though, that if you stop trying, that won't ever happen, because he'll figure you've written him off. Even if you only call him once a year, you're leaving the door open for him to get past whatever issues he has.
I'll also say, with regards to my use of quotatation marks above, you said that you can't choose your family. That's both true and false. I would rather say that you can't choose your relatives.
One of my biggest problems is that many of my friends come from families which were much more loving and stable than mine, and I keep expecting my relatives to magically fall into place. I had to recognize that that was not going to happen, and I have to keep reminding myself of that. Part of that is them, and part of that is me... and even if I fall into place (not always, or often, the case), they won't be there, and that jolts me further out of place. A good analogy would be that it's like cogs that don't fit together. The flip-side of that is recognizing that there are people who are my family, both relatives and not, and to be grateful for them.
So, just like you leave yourself open to the idea of new friends, you can, and probably do, leave yourself open to the possibility of new family. That includes your brother, and I hope that someday he can actually become family instead of a relative. Until then, I'd advise you to keep doing what you're doing, keep the door open, because he might decide one day to change.
Er, as an aside, I talk about myself because I'm a firm believer that people shouldn't try to understand each other, but should instead try to relate to each other. You can't relate to someone unless you hear their story, hence talking about myself. Anyway, I'm hoping you can find something in my rambling to relate to.
