You must both be really really really angry, + your wife's nerves quite frayed after the build up + thinking she was going to have an operation + next thing is no, she's got to go thru all the psyching up for it again

but ... I do believe in fate, i.e. in some way (that we shall never know) it is better that your wife didn't have the operation as scheduled. Here's hoping, however, for a new appointment + successful operation very soon