Thanks everyone. The surgery went well, and he's in the hospital recovering. I'm glad they went in at the time they did, the found microclots in his hand, but they were able to give him a bolus of Heparin to dissolve the clots before they could do extensive damage.
Because of that they're going to keep him in the hospital for a day longer in order to observe and try and make sure nothing happens. Again, thanks for all the thoughts and prayers, they are muchly appreciated.