Namine’s occupational therapist came to our apartment this morning to evaluate her. Tuesday marked a full two weeks of recovery after the Fontan (which is still crazy to me). It’s time to start thinking about getting her back into the swing of things, and that means therapy. Her right arm especially needs some attention, after having been through the wringer, so to speak, what with the central line and all that entails.
Before all that, though, Namine’s OT wanted to know what precisely having had the Fontan means. That is to say, what is her physiology, now that she’s finally had the surgery? (And if you don’t mind the reading, I’ll tell you too. I don’t know how much detail I’ve gone into about the Fontan in the past.)
So let’s back up a sec here. Namine was born with double-inlet left ventricle heart defect (DILV), and there are two important facts to know. First, there is no muscle wall dividing the bottom two chambers of her heart. This means that the blood coming in from her body (the deoxygenated, “blue” blood) and the blood coming in from her lungs (the oxygenated, “red” blood) mix, resulting in a much lower oxygenation.
Fast forward to the Glen – the second of three surgeries, performed when Namine was six months old – during which all blue blood above the heart is carried straight to the lungs by way of gravity and blood flow. This leaves the blue blood below the heart, which still mingles with the red blood in the heart’s bottom two (undivided) chambers.
Speaking in the simplest of terms, this remaining mixture of red and blue blood is what the Fontan means to correct. The result of a DILV patient having had the Fontan is that only red blood goes to the heart, to be pumped throughout the body; the blue blood, above and below the heart, is brought to the lungs to be oxygenated by way of gravity and the body’s own natural blood pressure and flow. And now Namine, having had the procedure, would ideally have an oxygenation of 100%, but this is not the case. Namine’s procedure has a built-in deliberate flaw, called a fenestration.
This fenestration is essentially a hole, made by the operating surgeon, which allows red blood to escape the heart during the pumping process. This lowers her oxygenation rate, but not dangerously so: she has had a steady in the low 90% without supplemental oxygen for some time. The fenestration also lowers the pressure inside her heart, making it safe to resume her normal activities without risk. The only real concern is the healing process, as her sternum, ribs, and muscles need time to mend themselves.