After agreeing to have no more children, a man and his wife decided he should have a vasectomy. What structure would then be surgically ligated?

In a vasectomy, the ductus deferens is ligated or excised. This means that the fluid that is then ejaculated from the seminal vesicles, prostate, and bulbourethral glands has no sperm. The sperm simply degenerate in the epididymis and the proximal ductus deferens. It would not be a good idea to ligate the ejaculatory duct or the seminal vesicle because that might compromise the patient's ability to ejaculate. Just remember, another name for the ductus deferens is the vas deferens, so it make sense that the procedure to ligate this structure is called a vasectomy. Ref: Cunningham F.G., Leveno K.J., Bloom S.L., Hauth J.C., Rouse D.J., Spong C.Y. (2010). Chapter 33. Sterilization. In F.G. Cunningham, K.J. Leveno, S.L. Bloom, J.C. Hauth, D.J. Rouse, C.Y. Spong (Eds), Williams Obstetrics, 23e.