Trish,
Well, if this were me, even though it's all sudden and shocking I like the speed of getting it taken care of....waiting will just ramp up the worry. If it has to get done, the sooner the better. Found the problem and quickly going to get it out...I think it's a smart decision.
Hoping all goes well and that Flynn gets through with flying colors and a speedy recovery!! You sound like you are in good hands with this vet.
Sending prayers and positive energy across the miles to you and Flynn!! He's a trooper and so are you!!
Will be awaiting the good word and with you all the way!!!

Barbara