Sounded to me like his situation is more of a gamble. He put his life on the line. If he cant get back to his heart in time he properly dies. When he says that he nor his bankai have 'life', he means they can't be killed.
Love the moustache. I hope Kubo doesn't kill him off just as he is getting good. I mean, his best fight so far was in the last filler arc.