Changing Out a Supra Pubic Catheter

I had a little learning experience the other day that I though I would share with you guys in case you run into this problem. I had to change out the supra pubic catheter on a guy but we could not get the catheter to track into the bladder. The catheter would track out from the stoma and out through his penis. So I placed a foley into his penis and inflated the balloon. Once I did that I instilled about 200 ml of saline into his bladder until the saline begin to come out of the stoma. I then inserted the new supra pubic catheter into the stoma, inflated the balloon and hooked it to the bag. I then pulled the foley out of the penis. The urologist told me afterward that since his bladder was empty, that may have caused it to track out the penis. Anyway, thought it might be a useful tool for someone in the future.