Thank you so much for your advice x
I am keeping my fingers firmly crossed! Hopefully the op is coming in time. It is always difficult when it happens in the evenings or on weekends as I know from my own experiences with emergencies where time is of the essence.
Take consolation that you have done exactly what any caring owner should do: do have given him a change and have made sure that he is in the most comfort he can be so he is not left suffering. You can never choose what or when something happens; all you can do is your best under the circumstances - which you have done!
Can you see whether another vet will operate today as a life or death emergency? This cannot wait until tomorrow!
If you feel overwhelmed by your fears, please try to commute the energy of your emotions by sending it onto your boy in the form of loving and healing energy. Praying is another way that does the same if that is coming to you more easily.
The wait for hearing back is always the worst time in my own experience as whatever happens, it can't be worse than your own imagination!