From here, a microcatheter (Pro-Great, Terumo, Somerset, NJ) was advanced coaxially through the base catheter with initial selection of the internal pudendal artery. Position was confirmed within the pudendal artery with injected contrast.
Greater than 75% increase in cavernosal artery diameter after injection of vasodilating agents, compared with pre-injection diameter is a good indicator of normal flow in cavernosal artery from internal pudendal artery. 
Inadequate embolisation of a PA due to extrauterine feeding arteries, such as the internal pudendal artery, ovarian artery, inferior epigastric artery, or contralateral uterine artery can lead to embolisation failure.
Karakhanian, "Case report: late recurrent hematuria following laparoscopic radical prostatectomy may predict internal pudendal artery pseudoaneurysm and arteriovenous fistula," Journal of Endourology, vol.