I am 7 years post op from robotic surgery and I was having rock solid erections the day the catheter was removed, but only with manual stimulation. The mental stimulation just didn't seem to work anymore after the surgery.
To this day I still get rock solid erections without drugs, but only with the manual stimulacion. I can look at naked women and think about sex 24/7 ,,,,but I just don't feel anything done there, no tingling, no movement, nothing. But the second the manual stimulation starts, in a matter of a 30 to a minuite , I am rock solid and will stay that way for as long as the stimulation continues. If I stop the manaul stimulation , I will loose the erection in seconds.
My nerves were spared during surgery so said the doc , but something else must have got disconnected during surgery. I remember the specifically the day before the surgery, I remember how I saw my wife naked and I had an rock solid erection almost immediately without any stimulation other then thoughts of sex. Two weeks after surgery, I looked at my wife in the same way and had thoughts of sex , but this time, I couldn't get an erection from thought alone like I did before. Not until the manual stimulation started did the erection come.