Teagan's 'technical' diagnosis is called Critical Aortic Stenosis with mitral stenosis, and left ventricle endocardial fibroelastosis. Basically the main valve in her left ventricle (the aortic valve) is really small (stenosed) and doesn't allow much blood to go through. In turn, her left ventricle didn't get to pump like it was supposed to so it is smaller than normal and the walls are very thick (fibroelastosis). Her mitral valve is also smaller than normal because of the deformed ventricle. She is being treated as if she had Hypoplastic Left Heart Syndrome but she has a left ventricle (its 75% normal size) and her aortic arch is fine. (Kiddos with HLHS usually have next to no left ventricle and usually have aortic arch narrowing)
Here's a rough sketch of what her heart looks like:
This surgery is only a temporary fix until Teagan could grow bigger and the pressures in her heart could adjust. Now that she's outgrowing her shunt its time for phase 2 the Bi-Directional Glenn. In the Glenn, the superior vena cava (major vein from the systemic circulation to head/upper body) is connected to the right pulmonary artery. This reduces the workload of the heart since it has to pump less blood to the body, not the lungs anymore. Now blood just flows to the lungs instead of being pumped. Her Sano shunt will also be taken down in this surgery. This will take a large amount of work away from her heart and allow her heart to relax a bit more. Right now her right side is doing the work of the whole heart so it is swollen and working very hard! The third stage The Fontan around age 3-4 will connect the lower body blood flow to the lungs thus giving her heart even more of a break and letting it only pump oxygenated blood to the body from then on.
I've been trying to focus on the positive side of things when thinking about the surgery tuesday. Don't get me wrong, its still gut wrenching to know what she'll be going through. But knowing how much better she will feel afterward and how much it should help her is reassuring. Each surgery is one step closer for her to being a happy, energetic, and healthier little girl and for that we are so so grateful!