There are two arteries in the spermatic cord—(1) the testicular a. and (2) the deferent a. The former and larger supplies the testis; the latter clings to the vas deferens and supplies it and the epididymis. The two arteries anastomose behind the testis. Tying the testicular artery, therefore, does not necessarily result in atrophy of the testis.
Surgical Anatomy. Arch Surg. 1996;131(7):698. doi:10.1001/archsurg.1996.01430190020005