Which procedure involves the cutting or sealing of the vas deferens?

The procedure that involves the cutting or sealing of the vas deferens is known as a vasectomy. This surgical procedure is performed as a form of male sterilization to prevent sperm from mixing with semen during ejaculation. By cutting or sealing the vas deferens, which are the tubes that carry sperm from the testicles to the urethra, the procedure effectively prevents the possibility of fertilization during sexual intercourse.

In contrast, orchiectomy refers to the surgical removal of one or both testicles and does not involve the vas deferens. Prostatectomy is the surgical removal of the prostate gland, typically performed to treat prostate cancer or enlargement. Vasostomy, which is not a common term, may indicate a procedure to create an opening in the vas deferens but is not a recognized surgical approach for sterilization.

Therefore, vasectomy is the correct answer as it specifically targets the vas deferens to ensure that the passage of sperm is interrupted, achieving its purpose of contraception.