Overview of Minimally Invasive Mitral Valve Surgery
As people live longer due to medical advancements, more and more people are developing issues with their hearts as they age. Mitral valve disease, a common heart condition that often comes along with aortic valve disease, is one of these issues. The mitral valve is located in the heart’s middle and when it’s not working properly, it can lead to other health problems, making the affected person weaker. Half of the people who have serious mitral valve disease, a condition where the valve doesn’t close tightly enough and allows blood to flow back into the heart, aren’t able to have surgery due to other health restrictions.
In the past, the treatment for mitral valve disease without surgery was limited and not very effective, leading to high mortality and hospitalization rates. However, recent medical advancements have provided a new option: minimally invasive mitral valve repair.
This type of surgery gives doctors a way to fix the valve through a small cut on the right side of the chest, rather than having to open up the entire chest. Not only does this method help preserve the heart’s structure and function, it can also lead to a quicker recovery, lesser chances of getting cuts or infections, and not as much physical trauma from surgery.
This less-invasive approach has been established as a global standard especially at bigger medical centers. It’s now also being used to help more fragile patients or those who have complex conditions related to their mitral valve, including infections.
Some of these less invasive surgeries include robotic repair, valve repair using a small opening on the right side of the chest, and methods that use a tube in the blood vessel to reach the heart to repair or replace the valve. Due to their less severe impact on the body, these techniques have been well received, and are continually improving. Because of these advancements, even those considered to be at a higher risk for surgery now have access to essential treatment options that can help them live longer and healthier lives.
Anatomy and Physiology of Minimally Invasive Mitral Valve Surgery
The mitral valve is a vital component of the heart, which is situated between the left upper and lower chambers, or left atrium and left ventricle. This valve is made up of several parts:
- Valve leaflets: The mitral valve has two flaps, referred to as leaflets, which are thin layers that open and close to control blood flow between the left upper chamber and lower chamber of the heart.
- Chordae tendineae: These are strong cord-like structures that fasten the valve leaflets to muscles called the papillary muscles. They stop the leaflets from bulging into the upper chamber of the heart during the heart’s pumping phase.
- Papillary muscles: These are muscles based in the left lower chamber attached to the chordae tendineae. When the heart contracts, these muscles tighten to avoid the mitral valve from bulging.
- Annulus: This is a tissue band surrounding the valve opening. It holds the valve leaflets and maintains the valve’s form.
The mitral valve is essential in maintaining the heart’s balance of blood pressure and volume, and its shape changes as the heart beats. Problems with the mitral valve can lead to heart disease, which can result in complications such as heart failure or abnormal heart rhythms due to the left upper chamber growing larger. Modern imaging techniques have improved our ability to see and assess any problems with the mitral valve. Two major issues that can occur with the mitral valve are:
- Mitral stenosis: This condition happens when the mitral valve leaflets become thick and stiff, preventing the valve from opening completely. As a result, it becomes more difficult for blood to flow from the upper to lower chamber on the left side of the heart. This causes increase in pressure in the upper left chamber and blood vessels from the lungs. This can decrease the amount of blood that gets pumped out from your heart and can cause symptoms like difficulty in breathing or fluid in the lungs. This condition often happens due to rheumatic heart disease. The preferred treatment for this is a procedure called percutaneous balloon mitral valvuloplasty that relieves the pressure difference between the upper and lower left chambers of the heart by increasing the opening of the valve.
- Mitral regurgitation: This condition happens when the leaflets fail to close properly, causing blood to leak backwards into the upper chamber from the lower chamber on the left side of the heart. This increases the amount of blood in the left upper chamber and can overload the left lower chamber. This can reduce the amount of blood the heart pumps out to the body, leading to symptoms of heart failure such as tiredness, shortness of breath, and heart dysfunction. Mitral regurgitation may be due to problems with the mitral valve (primary) or due to heart disease which affects the shape of the heart but the valve apparatus are normal (secondary). Management of this condition depends on whether it’s primary or secondary and requires a proper evaluation of the problem.
Why do People Need Minimally Invasive Mitral Valve Surgery
In simpler terms, the American College of Cardiology and the European Society of Cardiology have set some guidelines for treating a heart condition called mitral regurgitation, or MR. This condition is when a heart valve isn’t working like it should, making the blood flow in the wrong direction. How it is treated typically depends on how severe the MR is, and what caused it.
For an acute, or sudden, case of MR, doctors usually start with medicine to help manage the symptoms. If a person isn’t having any symptoms and their heart is generally pumping well (with a left ventricular ejection fraction or LVEF above 60%), they usually don’t need surgery right away. Still, if someone has chronic, or long-lasting, MR, shows signs of it despite taking medicine, or if their heart isn’t pumping well, they may need surgery. The standard surgery for serious MR is called Mitral valve repair, which has proven to be quite effective. It allows patients to leave the hospital sooner and provides excellent results in the long run.
However, if the problem is with the primary MR, that is, if the MR is not due to any other heart disease, doctors recommend surgery for patients with severe chronic MR and the LVEF of 30% or more. Surgery is also indicated for asymptomatic patients, meaning those who do not show noticeable signs but have left ventricular dysfunction when measured in their routine checks. Though the primary treatment is surgical repair, sometimes a percutaneous edge-to-edge procedure (a less invasive method) might be appropriate for patients who cannot undergo surgery or have a high risk during surgery.
In the case of secondary MR, or MR caused by other heart problems, surgical correction hasn’t shown that it helps people live longer. Yet, the percutaneous edge-to-edge repair method can help improve the quality of life and increase lifespan for people experiencing heart failure and moderate to severe MR, even when the medicine is not effective.
With advancements in treatment methods, more and more patients can now benefit from Minimally Invasive Mitral Valve Surgery. This less invasive surgical option is growing in popularity, especially for sicker and higher-risk patients, and even those with more complicated conditions, like valve infections.
Minimally invasive techniques, like a small incision in the chest, robot-assisted repairs, and the percutaneous edge-to-edge repair, have become more popular because they lower the risk of complications after the surgery and help patients get better faster. This is particularly true for patients who might not be suitable for traditional open heart surgery. As technology develops and less invasive treatments become more available, there are even more possible ways to treat patients with MR.
When a Person Should Avoid Minimally Invasive Mitral Valve Surgery
When it comes to treating problems with the mitral valve in your heart, there are many things we need to consider. For instance, less invasive surgeries, like small chest cuts (mini-thoracotomy) and robot-assisted surgery, offer certain benefits. They usually cause less pain after the surgery, you recover faster, and the scars are less visible. However, these kinds of surgeries are quite complex and need a skilled surgical team to make sure they work as effectively as the traditional surgery.
But not everyone with mitral valve issues can have these minimally invasive surgeries. Certain health conditions mean it would be safer and more effective to do a traditional surgery. Conditions that would prevent a minimally invasive surgery include certain illnesses or surgeries you’ve had in the chest area before, conditions that cause your blood vessels to become enlarged, issues with how the right side of your heart works or high blood pressure in your lungs, certain blood vessel diseases, issues with your body’s calcium levels affecting the root of your aorta or your mitral valve, recent strokes or diseases that affect your brain’s blood vessels, issues with your blood clotting, and severe liver problems.
Using a robot to repair the mitral valve has additional conditions where it wouldn’t be the best option, such as minor narrowing or leakage of the aorta, certain blood vessel diseases, variable high blood pressure in the lungs, chest shape abnormalities, heart artery disease, and moderate lung problems.
Given that mitral valve issues are more common in people over 65, many of these patients may not be suitable for surgery. In these cases, they might be referred for a different procedure, called percutaneous edge-to-edge mitral valve repair. This approach uses tiny cuts in the skin to fix the mitral valve and can be a good solution for patients who aren’t candidates for traditional surgery. However, this procedure shouldn’t be done in some patients, such as those who cannot tolerate blood thinning or anti-clotting medications after the procedure, have bacterial infections in their heart, have rheumatic heart disease, or have blood clots in their heart or veins.
Who is needed to perform Minimally Invasive Mitral Valve Surgery?
Mitral valve disease is a heart condition that needs to be treated through teamwork involving different medical experts. Getting better involves two main types of processes. The first is less invasive surgery, where the smallest possible cuts are made. This type of surgery is done by a certain type of heart doctor known as a cardiothoracic surgeon. They use modern techniques like robotic surgeries.
The second type is a procedure called percutaneous edge-to-edge mitral valve repair, which is less invasive and doesn’t require any large cuts. This is typically done by interventional cardiologists, who are heart doctors that treat heart conditions using thin, flexible tubes called catheters.
In certain situations, if problems come up during the valve repair procedure, the cardiothoracic surgeon and the interventional cardiologist work together. If they need to, they can switch to a slightly more invasive procedure called a mediastinotomy. Here, a small cut is made in the area between your lungs to reach your heart. This teamwork ensures you get the best care possible, improving your chances of feeling better quickly.
Preparing for Minimally Invasive Mitral Valve Surgery
Before undergoing minimal invasive heart valve surgery, there are several steps a patient must go through to prepare. All this preparation is handled by a heart specialist, also known as a cardiologist. One of the key steps in this process is a test called an echocardiogram. This test uses sound waves to create detailed images of your heart, allowing doctors to see how your heart and its valves are functioning. It can be done in two ways: either through your chest, which is called a transthoracic approach, or down your throat, which is called a transesophageal approach.
As part of the preparation, doctors also have to make sure any other health conditions you have are being managed as best as possible. This is important to ensure the surgery goes smoothly. You’ll also need to be declared fit to receive general anesthesia, which is the type of medication that puts you to sleep during surgery.
If you’re having surgical heart valve repair, you’ll have a meeting with the surgeon and anesthesiologist to get ready for the operation. If you’re set for a slightly different procedure, known as percutaneous edge-to-edge mitral valve repair, you’ll meet with an interventional cardiologist and an anesthesiologist. This procedure is performed in a specially equipped room, called a hybrid operating room.
All of this pre-operation planning makes sure every detail of your care is carefully planned and managed. The goal is to make the process as safe as possible and increase the chances of a successful surgery.
How is Minimally Invasive Mitral Valve Surgery performed
Mitral valve surgery can be performed through several less-invasive methods instead of a full chest opening surgery, known as a sternotomy. These methods include a partial opening of the sternum, a small cut in the right chest, or number of tiny cuts for a robotic-assisted surgery.
For one method, called a mini-thoracotomy, surgeons make a small cut in the right side of the chest, usually between the fourth set of ribs, although newer techniques use a small cut near the nipple for certain patients. In robotic procedures, tools are inserted through tiny cuts no bigger than 1.5 cm, facilitated by the use of robots.
Regardless of the method used, it’s very important to protect the heart muscle during the procedure. A technique called cardioplegia is used, it involves temporarily stopping your heart so that it can safely be operated upon. This is needed because these procedures may take longer than traditional open-heart mitral valve surgery.
Mini-Thoracotomy Approach
The mini-thoracotomy method is most commonly used. It involves circulating your blood outside your body, a process known as cardiopulmonary bypass. This is typically done by inserting tubes into large blood vessels in your leg, although it’s also possible to connect to the heart directly through the small chest cut. Additional techniques can be used such as vacuum assist and smaller cannulas, or tubes, helping the surgery go smoothly.
Percutaneous Edge-to-Edge Mitral Valve Repair
This method has the advantage of not requiring a cardiopulmonary bypass. Instead, the surgeon uses a special device to repair the heart valve using the following 5-step process:
1. Baseline Imaging: This helps visualize the area that needs to be treated.
2. Transseptal Puncture: A small hole is made in the wall between the heart’s upper chambers.
3. Positioning of the Clip: A special clip is placed in the heart’s left upper chamber, just above the affected valve. They might have to use more than one clip to get the best results.
4. Leaflet Grasp and Deployment of the Device: The faulty valve is then repaired.
5. Postdeployment Assessment: The health of the patient is closely monitored after the procedure.
TMVR
There are also devices being tested that assist surgeons in repairing the mitral valve. For instance, the Abbott Tendyne TMVR device shows promise, and it’s already approved for use in Europe. It is currently being evaluated for potential approval in the U.S. These less-invasive methods tend to result in less pain after surgery, quicker recovery, and better cosmetic results. However, they are quite complicated and require surgeons with specialized expertise to get results as good as traditional surgery.
Possible Complications of Minimally Invasive Mitral Valve Surgery
Minimally invasive mitral valve surgery, while beneficial, typically requires longer heart-lung machine usage times than traditional surgery methods. Not many trials compare traditional and minimally invasive techniques related to the after surgery results and complications. Studies suggest that even though the usage of the heart-lung machine is longer in minimally invasive surgery, the risk of stroke is about the same as traditional surgery methods. Other risks such as death, kidney failure, wound infection, additional operation for bleeding, tearing of the main blood vessel, heart attack, irregular heart rhythm, and re-hospitalization within 30 days are reportedly not significantly different between minimally invasive and traditional surgical procedures when the right patient is selected for surgery. The risk of stroke for minimally invasive mitral valve repair is reported to be between 1% and 2.6%. Also, using tubes for blood circulation outside the body can lead to infections in 1% to 7% of patients. Additionally, a small group of individuals might require a switch to traditional surgery methods during surgery due to complications.
A device used for non-surgical mitral valve repair is relatively safe, as indicated by the Endovascular Valve Edge-to-Edge Repair Study trial. This procedure shows low rates of requiring revival measures, heart attacks, kidney failure, and blood clots in the lung, ranging from 0% to 1%. The risk of stroke is between 0.4% and 1.4%, and significant bleeding risk is between 1.1% and 7.4%. Major bleeding is a common complication due to the need for blood thinners. Potential issues during the procedure include the chance of displacing a pacemaker during the procedure, which can be avoided by confirming its location with imaging techniques. Generally, the small hole made in the tissue separating the chambers of the heart for the procedure does not require closure as the risk of fluid build-up around the heart after the procedure is low. The most common implantation complication includes the device detaching from a single leaflet of the valve, happening in 0% to 4.8% of cases. Other uncommon complications include needing to remove the device surgically if it travels to a different location, formation of a blood clot on the device, or direct damage to the valve leaflet. There might be a blockage caused by the device placement on the valve, but this is usually acceptable depending on the evaluation of the health professionals conducting the procedure. An acceptable decrease in the condition might be a reason to tolerate a higher than normal pressure across the valve, as it can result in better long-term results.
What Else Should I Know About Minimally Invasive Mitral Valve Surgery?
Mitral valve repair is a surgical procedure that corrects problems with the mitral valve in your heart. The preferred method for this is a minimally invasive approach, meaning they use small incisions instead of a large one, which can be easier on the patient. This method is especially beneficial for those who might be at higher risk for surgery. Research has shown that this minimally invasive approach is just as safe and effective as the traditional surgery. Therefore, if you need surgery for a condition known as primary mitral regurgitation (MR), where the valve doesn’t close properly and makes the blood flow backwards, your doctors will likely consider a minimally invasive option.
In some cases, doctors can also perform an edge-to-edge repair procedure, which repairs the mitral valve without the need for open-heart surgery. This method is usually considered if you have symptoms of severe primary MR, meet specific criteria based on heart imaging (echocardiography), and either cannot undergo surgery or the surgery comes with high risks.
For a condition known as secondary MR, when the mitral valve is damaged due to problems in other parts of the heart, doctors usually don’t recommend surgical repair. But with the success of a similar method for treating the aortic valve, special devices are being developed for mitral valve repair. This means that, in the future, we could see more non-invasive options for treating both primary and secondary MR. More research is needed to determine the best approach for minimally invasive surgery and to compare its safety and effectiveness with other options.
