Overview of Aortic Valve Repair
The heart’s valves are put through a lot of work every single day – around 100,000 cycles! All that opening and closing adds up to roughly 3 billion times during an average 75-year lifespan, naturally leading to a lot of wear and tear. One of these is the aortic valve. We used to see this valve as a simple structure whose main job was to control the direction of the blood flow from the heart to the rest of the body, but now we understand it quite differently. It’s actually a lot more complex and helps your heart work at its best. (Picture this as The Aortic Valve.)
The aortic valve consists of several parts – the annulus (the ring-like base where the three leaflets of the valve attach), the cusps (the leaflets themselves), the sinuses of Valsalva (the outpouchings located behind each cusp), and the sinotubular junction (the area where the aorta begins to take its tubular shape). Imagine these components as a tightly-knit team that handles the pressure put on them by the flow of blood during every heartbeat. Just like the pieces of a well-oiled machine, these parts have to move in a precise and coordinated way to ensure the heart functions efficiently. If any part of the valve starts to fail – due to damage, disease, or wear and tear – it can cause significant issues for the body by disrupting blood flow. Conditions of the part of the heart where the aortic valve is located, like narrowing of the aorta, split aorta, or an abnormal bulging of the blood vessel, can all add more strain to the already stressed aortic valve, leading to even more issues. (You can see how the valve moves during the heartbeat here: Video. Aortic Valve Movement.)
So, what can we do when the aortic valve isn’t working as it should? The common solutions are repair or replacement. Repairing the valve involves a surgeon making fixes to the original valve to help it function properly, whereas replacement involves completely removing the faulty valve and putting in a new one. Despite it sounding like a straightforward choice, doctors must consider several factors – including the condition of the patient and the benefits and risks of each procedure – before deciding on the suitable course of treatment. (Deciding when to completely replace the valve can be seen in this image: Recommendations for Aortic Valve Replacement.)
Over the past decade, interest in repairing and preserving the aortic valve rather than replacing it has increased. This is particularly the case for treating disease in the area where the valve is located, even if the valve itself is also affected. Despite the rise in popularity, these repair procedures are still very complex and require specialized skills, leading to a small percentage of all valve procedures being corrective repairs. However, as they are less invasive and maintain the normal structure of the heart, these preservation procedures are starting to become a viable alternative to complete replacement. The potential to avoid long-term complications – like the valve wearing down, narrowing, infection, and bleeding due to needing medications to prevent blood clots – makes valve preservation an increasingly attractive approach to improving patient health outcomes.
Anatomy and Physiology of Aortic Valve Repair
The aortic valve, which is a key part of the heart, has a detailed structure that doctors need to understand when performing heart surgery related to it. This valve is made up of a few main parts: the place where the heart and aorta meet, called the ventriculo-arterial junction, a spot called the sinotubular junction, the valve ‘leaflets’ (which control the flow of blood), and areas known as ‘sinuses’. Each of these parts plays a unique and important role in how the valve functions.
The aortic valve begins near the aorta, a large artery in your body. Inside the part of the valve that’s connected to the aorta, you’ll find the leaflets, which work like doors to control the flow of blood, as well as other structures such as triangles and junctions. The middle of the leaflets typically is at the precise height between the sinotubular junction and the ventriculo-arterial junction.
It’s also useful to know that the aortic valve has a base, and this is where the leaflets are attached. It has an interesting shape and includes three sinuses or spaces. Two of these sinuses connect to the main arteries that supply your heart with blood; the third one doesn’t and is referred to as the ‘noncoronary aortic sinus’. These sinuses get their names based on their location: one is in front (right coronary), one is at the left back (left coronary), and the other one is on the right backside (noncoronary).
Now let’s talk about the important components of the aortic valve:
The ventriculo-arterial junction is a part of the valve that bridges the gap between a part of the heart and the aorta. It’s like an ellipsoidal border. Its diameter is usually 23 mm in adults. It’s the spot where the heart muscle ends and starts to merge with the aortic wall. During an operation, this represents the hinges of the leaflets. The place where each leaflet attaches to the ventriculo-arterial junction is crown-shaped and is known as the aortic annulus.
The sinotubular junction is a circular ridge locating between the upper straight part of the aorta (the ascending aorta) and the lower swollen part, called the aortic root. It follows the upper contour of the three sinuses and intersects the commissures of the aortic valve. It is generally larger than the base of the valve, with a sizing ratio of 1.3.
When it comes to the aortic leaflets, the size is very important, as it helps the doctors to evaluate if there is any drooping or shortage of tissue. During an operation, it is crucial to measure the size and height of these leaflets. The geometric height represents the longest distance from the bottom of the leaflet to the top, while the effective height is the distance from the base plane to the middle coaptation point.
The sinuses of Valsalva are the swollen regions of the aortic root that hold the leaflets and provide openings for the coronary arteries to supply blood to the heart.
Having a good understanding of the detailed structure of the aortic valve is crucial for performing successful heart valve surgeries. This understanding helps the surgeon to maintain the normal structure and function of the valve, and possibly prevent problems that might occur from valve replacement.
Why do People Need Aortic Valve Repair
If your doctor finds that the aortic valve in your heart (the main valve that lets blood flow from the heart to the rest of the body) is not working well, they might suggest surgery. This surgery could be to repair or replace the valve. However, repairing the aortic valve has been found to have fewer complications during the surgery period.
Situations that may lead to aortic valve repair include:
– If you have a problem where your aortic valve doesn’t close all the way or at all (either you have symptoms or you don’t): This usually happens to people whose left ventricle (the lower left chamber of your heart) has stretched out. This can be seen if the diameter of the left ventricle when it’s squeezing (end-systolic) is more than 50mm and when it’s relaxed (end-diastolic) is more than 70mm, or if the left ventricle isn’t working well.
– If you have a problem with the root of your aorta (where the aorta begins) or the ascending aorta (the part of the aorta that runs upwards from the heart) and this affects your valve: The aortic valve repair is recommended in such situations.
– If your aortic valve leaks or doesn’t close properly: Repairing the aortic valve is the first choice of treatment here.
Repairing the aortic valve can help retain the function of the original valve and can lead to fewer complications compared to replacing it. The final result of the repair depends a lot on how big and good quality the valve flaps are that can be repaired. If your aortic valve has serious damage, a lot of hard deposits (calcifications) or has been damaged by a disease that affects the heart due to strep throat (rheumatic heart disease), then repair might not help much. On a brighter note, repairing the aortic valve has shown good results for patients with a single-flapped (unicuspid), two-flapped (bicuspid), or four-flapped (quadricuspid) aortic valves.
When a Person Should Avoid Aortic Valve Repair
Occasionally, it might not be possible to carry out an aortic valve repair surgery. This can occur if the parts of the heart valve, called the valvular apparatus, cannot be fixed. Doctors need to thoroughly check these heart valve parts before any surgery is drawn up. For instance, if the flaps (or “leaflets”) of the heart valve are too soft, hard and inflexible due to calcification (a hardening process), or retracted (pulled back or shrunk), surgery may not be an option.
Patients with such unmanageable heart valve parts should not be suggested this type of surgery, as it could lead to complications.
Before the surgery, a type of heart scan called a transesophageal echocardiogram (TEE) should be done. This test allows doctors to closely examine all the different parts of the heart valve, such as aortic annulus (the outlet of the heart), aortic sinus (an area inside the heart), and STJ (the place where the aorta meets the heart).
It’s also important that the surgery happens in a place with experienced doctors and a good team of heart doctors, heart surgeons, and anesthesiologists (doctors who ensure you’re safe and comfortable during surgery). Ideally, surgeries like this should happen in big medical centers that do a lot of them because they usually have more experience and resources.
Equipment used for Aortic Valve Repair
The surgery done to repair or save the aortic valve is carried out under general anesthesia. This means you’ll be completely asleep and won’t feel anything during the operation. All patients going through this procedure will need a method called ‘antegrade cardioplegia’. It’s a technique which momentarily stops the heart using a special solution, to protect it while the surgery is being performed. This solution is introduced either through the base of the aorta (the main blood vessel in your body) or directly into the openings of the coronary arteries if a condition known as ‘severe aortic insufficiency’ is present. ‘Aortic insufficiency’ is when the aortic valve doesn’t close tightly, allowing some blood to flow back into the heart, which forces the heart to work harder than it should.
If the patient also needs an ‘ascending aortic replacement’, a Dacron prosthesis will be used. This means, if the part of your aorta that’s close to the heart also needs replacing, a man-made material known as Dacron will be used to create the new portion of the aorta.
The way the blood vessels are accessed during surgery (known as ‘arterial cannulation’) can change depending on the condition of the aortic arch, which is the part of the aorta that bends between the ascending and descending sections of the aorta. If there’s an aneurysm (a bulge or ‘ballooning’ in the blood vessel wall) that extends to the aortic arch, the doctor might use either the axillary artery (located in your armpit) or the femoral artery (in your thigh) to gain access for cannulation.
Who is needed to perform Aortic Valve Repair?
If you need to have your aortic valve (a valve in your heart) repaired, it’s best to have the procedure done at a hospital that does this kind of surgery a lot. Because this type of surgery isn’t done very often, it’s important that the surgical team is very good at working together. This will help everything go smoothly during the surgery.
There are some key people who will help with your valve repair. Anesthesiologists, who are doctors that make sure you’re asleep and don’t feel pain during the surgery, and cardiologists, who are heart doctors, are important. These doctors need to have a lot of skill using a special tool called a TEE (Transesophageal echocardiography), which helps view the heart and blood vessels. Other than the main heart surgeon, there should also be one or two other surgeons to help out, as well as a surgical technician, who helps with equipment and tools.
Also, there must be experienced nurses to aid the anesthesiologist and the rest of the surgical team. All these professionals work together to make sure you get the best care during your surgery.
Preparing for Aortic Valve Repair
Before heart valve surgery, doctors carry out several tests including an ECG, a special type of X-ray, a heart CT scan or angiogram (this is where they inject a dye into your blood vessels so they can clearly see how blood flows through your heart), and a heart ultrasound (this uses sound waves to create a picture of your heart). For those who’ve had heart surgery before, doctors will also carry out an extra CT scan of the chest.
It’s also important for you to get checked by a lung doctor (pulmonologist) and a heart doctor (cardiologist) to make sure your heart and lungs are working as best as they can before the surgery. The doctor will talk through exactly what they plan to do during the operation, and the reason behind it. You’ll also need to give your permission for the operation to go ahead.
Once you’re in the operating room, one of the team members will run through a safety procedure. This includes confirming your details, naming the procedure, and reviewing all important medications and any allergies you might have. After you’re given medication to help you sleep (sedation), they’ll prepare you for surgery using a clean technique to avoid infection.
In the operation theater, they’ll use a special kind of ultrasound called a TEE to measure different parts of your heart. This gives them a more detailed understanding of your heart. The surgery team will work closely with heart doctors and anesthetist who are experts in using this ultrasound technology during your operation.
How is Aortic Valve Repair performed
Aortic valve repair is a procedure used to fix issues with the aortic valve in the heart. It’s known to have really positive results in the medium to long term and being careful and using standard methods can really increase the chances of success. This operation can be divided into two main sections: fixing the aortic root and the ring around the valve (annular), and fixing the valve flaps themselves (cusp).
There are three main forms of aortic valve issues:
– The first type is when the aortic root is too large. This causes the valve flaps to stretch and become misaligned, causing leaks back into the heart’s main pumping chamber.
– The second type is due to an excess of tissue on the valve flap which can cause it to flop backward, resulting in off-center leaks.
– The third type is the hardest to repair surgically. Here, stiffening and hardening of the valve flaps due to calcified deposits cause them to retract or pull inwards.
Typically, all three of these issues can exist to some degree in most cases. The European Society of Cardiology and the European Association of Cardiothoracic Surgery have further classified these types of aortic valve situations.
One method of repair focuses on fixing issues with the aortic root and the valve ring. This usually applies to the first type of aortic valve problem where the valve leaks due to dilation or stretching of any part of the ring around the aortic valve. Depending on the specific issue, repairs can involve various methods.
Another technique is called ‘Valve-Sparing Root Replacement’. This method came into use in 1983 and has become increasingly popular in patients where the problem is due to enlargement of the aortic root. The surgery involves either reshaping the aortic root with annuloplasty or replacing the aortic root while leaving the valve in place. This might be particularly useful when the valve has three flaps and the leakage is occurring centrally (straight back into the main pumping chamber) or in patients with two flaps where the leaks are off-center.
In some cases, the problem might specifically lie within the aortic valve itself (type 1 and type 2 aortic insufficiency). In these cases, there is an effective technique to repair issues like flap dangling, old age changes, and other malformations that are causing the valve to leak. In patients with ring and aortic root abnormalities, a procedure to repair those may also be done. However, this procedure doesn’t work well when the issue is related to hardened valve flaps (type 3).
Like most surgeries, there can be unforeseen issues that crop up during the operation. Therefore, it is vital to continually monitor the patient’s heart function throughout the procedure using echocardiography. This allows doctors to quickly return the patient to bypass if unexpected complications arise, ensuring the best possible outcome for the patient.
Possible Complications of Aortic Valve Repair
Repairing the aortic valve is a big job and takes a team of skilled doctors. Unfortunately, there can still be complications, even though you’re receiving the best care. Load up on information about the potential problems that could crop out below.
Early Complications
Some problems can show up right after surgery. These are often due to mistakes made during the operation. Here are a few you should know about:
* Low coaptation: Coaptation is when the flaps of your heart valve come together properly. If they don’t, it’s called low coaptation. Doctors can spot this during or after surgery and will make adjustments to fix the issue.
* Residual prolapse: Prolapse is when one of your heart valve’s flaps sags or falls down. If any prolapse remains after surgery, your doctor will need to address it.
* Cusp perforation and missed fenestration: During surgery, a doctor may accidentally puncture the valve’s cusp. If this happens, they’ll need to repair it right away. Also, if there’s a sizable hole, or fenestration, in the valve, it, too, will need to be addressed.
* Patch Dehiscence: After surgery, a special patch may be used to hold the aortic valve and aortic root in place. If this patch comes loose during recovery, another surgery may be necessary.
* Rupture of the anterior leaflet of the mitral valve: If the mitral valve, a valve close to the aortic valve, is accidentally punctured, it may cause a condition called mitral regurgitation. This needs to be fixed as soon as possible to keep the heart from being overworked.
* Hematomas: Some surgeries lead to localized bleeding that can cause small collections of clotted blood called hematomas. These usually absorb back into the body after a few days.
* Complications related to subcommissural annuloplasties: Known as annuloplasties, these surgeries designed to tighten up the aortic valve can sometimes cause complications. They can damage the structure of the valve, causing fistulas or pseudoaneurysms, serious conditions that need quick attention—either right then or possibly later in another surgery.
Delayed Complications
Sometimes problems don’t show up until months or even years after surgery.
* Late-onset persistent aortic insufficiency: Even after a successful procedure, some issues can still develop. One is a small prolapse or when the valve’s flaps don’t come together properly. Over the years, this can become more serious. In the same way, the main blood vessel stemming from the heart can slowly widen, leading to ongoing issues with your aortic valve.
* Endocarditis: It’s quite rare, but there have been cases where repaired valves have become infected. This is known as endocarditis.
* Bleeding: Again, rare but can happen – some patients might experience bleeding a while after the surgery. Doctors aren’t exactly sure why this happens.
* Thromboembolism: This is a fancy way of saying a blood clot that moves through the blood vessels. It’s not common but has happened in a small number of cases.
* Progressive valve fibrosis and calcification: Sometimes, even with a successful repair, the valve can continue to harden over time.
Finally, a recent study shows that replacing the aortic root, a technique often used when repairing the aortic valve, is effective in the long term for most patients. However, patients with a two-flap aortic valve may have to go back for more procedures compared to those with a three-flap valve. Even with this slightly higher risk of needing another procedure, doctors believe that this treatment is reliable for both types of patients.
What Else Should I Know About Aortic Valve Repair?
A damaged aortic valve, which controls blood flow from your heart into your main artery, can be treated using custom surgical techniques. This procedure, which is becoming more common, can help patients with both types of aortic valves – those with three cusps (tricuspid) and two cusps (bicuspid). The operation not only fixes the valve itself but can also address problems in areas both above and below the valve. Studies have shown that if done carefully, the results can be as good as a full valve replacement.
The Heart Valve Society has developed an international registry called the Aortic Valve Insufficiency and Ascending Aorta Aneurysm International Registry (AVIATOR). This collects data of patients who have diseases associated with the aortic valve and the part of the aorta closest to the heart, regardless of the treatment they undergo. The aim is to map out the entire journey patients with these conditions take, from diagnosis to death, helping to increase our understanding and improve treatments. Data from any medical centers dealing with these conditions is welcomed, it does not have to be from a specialist heart center.
Evidence from these centers is being progressively published. A study from Croatia observed that performing operations to fix the two-cusp aortic valve along with additional procedures to support the valve led to excellent results in the mid-term and had low associated risks. These results were as good as those achieved when operating on the three-cusp aortic valve.
Special attention is needed for repairing a two-cusp aortic valve, a condition that affects 1-2% of people. People with this condition often start experiencing symptoms when they’re relatively young. Over the last two decades, techniques for fixing this specific valve and associated issues, like heart aneurysms, have improved significantly. Initially, while short-term results of valve repair were excellent, some patients needed more operations later down the line. Nowadays, problems that may have caused the initial surgery to fail are identified and fixed during the first operation to make the repair last longer. Also, it has been found crucial to fix any stretching of the aorta at the same time, which has helped to improve long-term results.