Vas-occlusive contraception consists of partially or completely blocking the vas deferens, the tubes connecting the epididymis to the urethra. While a vasectomy removes a piece of each vas deferens, the intra vas device (IVD) and other injectable plugs only block the tubes until the devices are removed. The U.S. Food and Drug Administration (FDA) approved human clinical trials for the intra-vas device in 2006.[47]