How does a cut spermduct prevent pregnancy?

A cut sperm duct, or vasectomy, prevents pregnancy by interrupting the pathway through which sperm travel from the testicles to the urethra. During the procedure, the vas deferens is severed and sealed, preventing sperm from mixing with semen during ejaculation. As a result, the semen released during ejaculation contains no sperm, effectively preventing fertilization of an egg. This method is considered a permanent form of male contraception.