There are few options. MESA, PESA, TESA and TESE. It really depends on the severity of the problem. TESE is the most invasive of all and it is once and for all procedure. My DH has abnormal volume so needle aspiration related techniques are out of the question so we have to go with TESE. Other non-invasive, less expensive procedure might be an option for your DH since he does have sperms in his ejaculation. I am very new here so other people might have better idea than me. I find that the cornell urology site is very informative about differerent procedures. In fact, mTESE is the brain child of Dr. S at Cornell urology dept.
I don't know the pain level after the TESE surgery. I was told that the procedure will take at least an hour. That means one will be put under for at least that long.
I assume your FS knows enough not to give straight testorone boost? Is there any explanation why he isn't producing?