I just called the cath lab to check in and got an update. The cath itself is going fine, but they did find that the pressures in his superior vena cava were quite high, which is what has caused his abnormal head growth. He said that they also found a number of collateral veins. They aren't sure yet what they're going to do about it. They can coil off the veins, but he said that that wouldn't totally fix the problem, and that it may be better to treat him with medications. So, the cath doctor is going to consult with our cardiologist and maybe the cardiac surgeon to figure out what to do. He said they'll probably be there for another couple of hours, though.
I guess it's good that they figured out what's going on. It's not so great that it seems to be something not easily fixed. But I guess at least they do have some options.
4 months ago