Elizabeth H. Stephens, M.D., Ph.D., a pediatric and congenital cardiac surgeon at Mayo Clinic in Rochester, Minnesota, discusses the anatomy, physiology and surgical management of tetralogy of Fallot.
Tetralogy of Fallot findings include a ventricular septal defect and often a narrowed pathway to the lungs that can cause babies to turn blue. Although the first surgical repair is performed in infancy, these patients frequently require re-operation on the pulmonary valve as teenagers or adults.
My name is Elizabeth Stephens. I'm a pediatric and congenital cardiac surgeon at Mayo Clinic. Today I'll be discussing tetralogy of fellow. One of the things that I love about tetralogy of fellow is that at central to the history of cardiac surgery, the blue babies who were seemingly miraculously cured by the truly pioneering work of Dr Blaylock, Vivian Thomas and Dr Helen Taussig were tetralogy babies. And from there the field of cardiac surgery grew. Tetralogy of flow is due to the position of the muscle below the aorta, called the infant tabular septum. Not being aligned properly. That leads to the major characteristics. Sub tetralogy the VSD, or hold between the ventricles, the narrowed area of the right ventricular outflow tract or area below the pulmonary valve and narrowing of the pulmonary valve. Shown in this diagram is the pulmonary valve. The Blue star indicates the infant tabular septum, which doesn't line up with the rest of the septum below, creating the VSD shown here and also results in the narrowing of the pulmonary valve area. This snaring is also shown in B and is what causes patients to be blue because not enough blood flow is reaching the lungs in See the repairs shown with the VSD patch and in this example, the transacting their patch, which opens up the pathway to the lungs. The physiology of each baby depends on how much flow is getting to the lungs and blue tetralogy. There's less flow to the lungs, and their oxygen saturation is lower. While in pink tetralogy, their physiology is more like a straightforward BSD, where the lungs received too much blood flow and their saturation zehr fine. But they may have trouble eating and gaining weight in terms of management. Some babies will show symptoms such a spells of low saturation relatively early, while others will not. Those who do have symptoms can frequently be managed for a while with medications, but some will need early repair. In general, we aim for elective repair at 3 to 6 months. The goals of the repair are to close the hole in the heart, which is done with a patch and improve flow out to the lungs. In some babies, their own pulmonary valve can be used. This is called valve sparing, and we wide in the areas above and below the valve. In other cases, the valve in area around the valve, called the Analyst, is too small in this area will need to be patched. This is called a trans Endler patch repair, which is shown here. There are also usually muscle bundles under the poor Marie valve that are respected. Thes babies have a good prognosis, and this is an operation that we commonly perform. They usually stay in the hospital around five days or so and then are discharged with follow up appointments with our cardiologists. We at Mayo Clinic in particular, see a lot of teenage and adult patients who had a tetralogy repairs a baby frequently. Over time, these patients will need the poor. Marie vowed to be readdressed. Some of these patients can be managed with a trans catheter pulmonary valve replacement done in the cath lab without open heart surgery, while others, depending on various factors, may need open surgical valve replacement. Thankfully, once we put in that open surgical valve in these patients, and this is a tissue valve that does not need anticoagulants in long term. When that valve breaks down, that valve can usually be replaced in the cath lab with a trans catheter technique I hope you have found this video helpful and be sure to check out our other educational videos on the Mayo Clinic YouTube channel as well as our website.