For anyone considering SpaceOAR rectal spacer, here's my experience one day after the procedure.
While I see some have had this done under anesthesia, I did not. It was not presented as an option for me, and after going through it, I don't know that it would be necessary unless you have a very low tolerance for pain. I don't handle anesthesia well, so while I was anxious going into the procedure, it was not as bad as my brain was telling me it would be. I would say the biopsy was slightly less comfortable.
I was given antibiotics to begin the day before through the day after the procedure, Valium for the day of the procedure to help calm my nerves (would have been nice for the biopsy), and a lidocaine patch to put in place an hour before the procedure.
Upon entering the procedure room, I undressed from waist down, got onto an exam table and then had my legs propped up in stirrups, much like women have to frequently do for their gyno exams. My balls were then taped up to be out of the way and the lidocaine patch removed. Then the procedure began.
While the lidocaine patch was supposed to numb the injection sites for the local anesthetic, it didn't do so well for me. I tolerated it, but there are a lot of nerves down there, and the pokes and the sting from the anesthetic being injected were not pleasant for me. Fortunately, the four shots were done quickly and it subsided immediately. Then came the rectal ultrasound probe. I would assume you all are familiar with this part by now. The final part was the injection of the hydrogel. I did not feel this injection at all, despite the use of an 18 gauge (approx 1mm diameter) needle (I actually thought it would be larger). Just before starting the injection, my physician said I would feel pressure like I would need to have an immediate bowel movement, but to know that was normal sensation to expect. His description was spot on. It was definitely uncomfortable, but not painful like the injections. I found the immediacy feeling subsided within a few minutes, but I still felt full. I was then tidied, released of the"hammock". No bandage or anything to manage after either, which surprised me, as I thought of it as a rather vascular area. You will have spotting in your undergarments at the end of the day, but it was quite minimal. I was then sent on my way home via my ride (due to the Valium). It all went by quite quickly, 15 minutes I would estimate.
Throughout the day, I was well aware I'd had the procedure, but it made itself known mostly during sitting, similar to the biopsy, but not as noticable while standing. I would equate it as the feeling of putting pressure on a bruised area, as essentially that is what it is. By the end of the day (I had the procedure early in the morning), I did not feel the pressure associated with the hydrogel, and had no issues through the night.
Today, I took the dog for a walk, no issues. I'm still aware of the bruised feeling while sitting, but it's much less already. Overall, it's definitely the anxiety of the upcoming procedure that was the worst part.
Hope this helps give some ideas to others preparing for this. I know everyone's mileage varies, but mine was not too bad.