Although the vas deferens are convenient targets for
male contraception, the complete obstruction of sperm
transportation as a routine male contraceptive method
may lead to irreversible damages to fertility or other
health problems. Modified vasectomy via the testicular
end-opened and filtering-type intra-vas devices may be
alternatives. In other taxonomic groups (e.g., primates,
ungulates, marsupials, and rodents), in which multi-male
groupings are common, reversible male sterilization
techniques could control male reproduction without
eliminating their future reproductive capacity or social
interaction[29]. The complete obstruction of the vas deferens
as a traditional method of vasectomy is not absolutely
safe in the long run. Techniques of relieving the
inner pressure of the vas deferens while maintaining the
efficacy of male contraception need to be explored.