Thanks for your query.You have undergone vasectomy
8 years back and now ant it to be reversed to impregnate your girl friend. Normally results of the reversal of vasectomy are not encouraging Moreover it has been 8 years have passed after your vasectomy and sperm antibodies
have already been formed in your body .So there are hardly any chances of spermatogenesis
to produce the sperms even after reversal of vasectomy.