Pregnancy after vasectomy reversal?

Can someone give me any information, facts, details, etc.... my 46 yr old hub is scheduled to have surgery for reversal in three weeks, and we've been told since it's been 11 years since the original procedure, we're at 50/50 odds at ever having success. I'm worried another factor is our ages (he's 46, me 34).... my hub is in the attitude, I'm not going to have this surgery to fail and we'll have everyday until you are preggers; I'm afraid of him doing this with no happy outcome..... Anyone in the medical field or personal experience?