Here is a picture from the cath--you can see the difference in size between the left and right pulmonary arteries (dyed for the cath):
What is perhaps most alarming about this picture is that there appears to be a small, dark swan swimming around in Sam's upper ribcage. Hmm.
Because of the discrepancy between his left and right pulmonary arteries, however, Sam will likely experience some complications after his Fontan and have a lengthy hospital stay (at least a month), but he is squarely in the candidate range. He just needs to keep growing and gain about five more pounds. In the world of hypoplastic left heart syndrome, this is what we call cautiously optimistic news. My favorite moment with the doctor, though, was when he told us that Sam is a "very popular guy around here." He is a pretty popular guy with us, too.
Thank you for all of your prayers, wishes, and good thoughts.