News about Zachy's Head

We had our appointment with the specialist and they confirmed that Zach needs surgery. The quick version is that his skull sutures have fused together too early and only surgery will correct this. I could blog for hours about the thousands of questions that we now have or about all our fears and worries. But I'm just not going to go there today.
At this point, we are waiting on the scheduling and insurance details. First, Zach needs to have a CT scan of his brain to make sure that everything looks normal. There is a small percentage of patients with this condition that end up having one single frontal lobe of the brain instead of the normal two lobes. We were reassured that this condition is very rare but of course, we have to add it to the list of things to consider.
Surgery will be scheduled for some time in the next two months. The sooner the better, I guess. They informed us it's always so much easier when the child is not walking yet. Ironically, we have been noticing lately that Zachy may end up skipping the crawling stage and go straight to walking.
Donny and I are proceeding as if we are going to go forward with the surgery but we are weighing all the details and risks and have not actually "decided" that this is what we will do.
It is a major surgery and the doctors explained briefly that it is very, very bloody. Most patients require a transfusion because of the blood loss. Zach will have to be hospitalized for at least four days, assuming things go well. There are the risks of infection, brain damage, and death.
If we don't do the surgery, his head will continue to grow from all angles but the front. I would assume, this will cause him to be severely disfigured. And of course that would affect all areas of his life.
How does a parent make a decision like this?