What is Paravalvular Leak?
Paravalvular leak is a leak around a valve replacement. A form of leaky heart valve. When someone has valve replacement surgery they have a new valve put in place. This valve is usually put in place with no gaps between the edges of the valve or the surrounding natural heart tissue. Sometimes gaps can be left or develop around the replaced valve known as Paravalvular defects. Blood can leak through these defects, known as Paravalvular leak. If the leak is significant it can lead to symptoms. Paravalvular leak is also known as perileak, perivalvular leak, and periprosthetic leak.
Why Do Paravalvular Leaks Happen?
In surgically replaced valves, the valve is stitched into place by a surgeon. These stitches can become loose, often due to wear and tear and often due to the fact that there is a lot of calcium in the natural heart tissue and the stitches simply pull through. Once they become loose a Paravalvular defect occurs allowing a Paravalvular leak.
In minimally invasive placed valves, such as in the TAVR procedure, valves are typically expanded in to place, but sometimes due to the presence of hard pieces of calcium in the natural heart tissue the valves cannot fully expand. These areas can lead to Paravalvular defects and Paravalvular leak.
How Long After Surgery Do Paravalvular Leaks Happen?
Most commonly paravalvular leaks occur many years after valve replacement surgery and simply due to wear and tear. Unfortunately this can sometimes be seen soon after surgery due to stitches becoming loose or tissue tearing through the stitches and not holding in place. This is frustrating, however it can happen even in the best of hands. In the case of TAVR procedures, the leak can usually be seen immediately and if large enough can be taken care of at that time so patients can leave the operating room without significant paravalvular leak.
How Much Paravalvular Leak is needed to Cause Symptoms?
In general small Paravalvular leaks will not cause symptoms. The exception is in a condition called hemolysis where the leaking of blood can lead to destruction of red blood cells and cause anemia due to the blood count dropping low. Hemolysis can occur with larger leaks also. Paravalvular leaks that are moderate or severe in nature can lead to symptoms.
What are the Symptoms and Signs of Paravalvular Leak?
The most common symptom of a significant leak will be that of heart failure. This can include shortness of breath, swelling, heart flutter, atrial fibrillation, and easy fatigue. Symptoms will typically be worse with exercise. On examination, patients may have evidence of fluid retention and patients with Paravalvular leak will typically have a heart murmur.
How is Paravalvular Leak Diagnosed?
Patients with Paravalvular leak will often have a heart murmur that can be picked up with a stethoscope. Once there is a suspicion for Paravalvular leak then patients will undergo a test known as a transthoracic echocardiogram (TTE), an ultrasound scan of the heart. Paravalvular leaks are often hard to diagnose however, and may not be picked up by the transthoracic echocardiogram. Often, a test known as a transesophageal echocardiogram (TEE) is used. In the TEE test, a small echocardiogram probe is passed down the food pipe and used to obtain very high-resolution images of the heart in great detail. This is the gold standard way of diagnosing the Paravalvular leak. Personally, when investigating para-valvular leaks I will perform a 3D-TEE, to not only diagnose the defect, but also to obtain useful information regarding how to fix it.
Is there medicine for Paravalvular leak?
Paravalvular leak is a mechanical problem and so the only definitive treatment is to fix it. Patients with signs and symptoms of heart failure may need diuretics. Diuretics are water tablets to help get rid of excess fluid and may improve symptoms until the defect can be fixed. In patients with anemia related to hemolysis from the defect as described above, blood transfusions may be required for symptomatic treatment until the defect can be fixed.
How can Paravalvular Leaks be fixed?
Traditionally patients have required repeat open-heart surgery to fix Paravalvular leaks. However recent advancements in technology means that in a few expert centers such as Princeton Baptist Medical Center in Birmingham, Alabama, minimally invasive techniques can be used to repair these defects. This is known as percutaneous repair of paravalvular leak.
In the case of surgical repair, the procedure is an open-heart procedure and will typically involve placement of a new valve. The risk is of course higher with open-heart surgery and depends on other factors such as how well the patient is in general.
In the case of minimally invasive percutaneous repair, the defect is repaired through a small tube placed in to the artery in the leg. The equipment is passed up to the heart through these tubes and plugs are placed obliterating the leak. After performing this procedure I’ll often send Paravalvular leak patients home the next day. The following animated figures demonstrate the imaging acquired during a repair procedure using a trans-esophageal echocardiogram and a fluoroscope. Expert use in these imaging techniques is required in order to safely and effectively perform such a procedure.