Heart valve reconstruction: information & specialists

When is a heart valve reconstruction necessary?

The human heart has four heart valves.

Two heart valves, the leaflet valves, lie between the atria and separate them from the ventricles:

• the tricuspid valve on the right and
• the mitral valve on the left.

Two other heart valves, the pocket valves, close the openings of the ventricles to the large arteries:

• the aortic valve (left) to the aorta and
• the pulmonary valve (right) to the pulmonary artery.

All four heart valves can become diseased and must then very often be treated by heart valve surgery.

There are two main diseases of the heart valves:

• heart valve stenosis and
• heart valve insufficiency.

The four heart valves: The leaflet valves are on the outside, the two pocket valves are on the inside © Martin | AdobeStock

In valvular stenosis , the heart valve does not open sufficiently. As a result, less blood flows through it. This leads to an increase in pressure in front of the valve (inside the heart).

If the heart valve does not close properly, this is known as heart valve insufficiency. This means that blood flows back into the ventricle after passing through the heart valve. The result is so-called shuttle blood.

Both stenosis and insufficiency put more strain on the heart. In order to exert more force, the heart enlarges, i.e. the heart muscle thickens and the heart chambers expand.

Above a certain wall thickness, the heart muscle is insufficiently supplied with blood, so that heart failure (cardiac insufficiency) is imminent. To prevent this, doctors may decide to perform a heart valve reconstruction.

Heart valve reconstruction on the open heart

In the majority of cases, heart valve reconstruction is performed using open heart surgery. The surgeon opens the chest directly above the sternum and exposes the heart. In order to treat the heart valve, the heart must be stopped. A heart-lung machine takes over the circulation as long as the heart is not beating.

During heart valve reconstruction surgery, the patient is under general anesthesia and thus sleeps through the procedure.

There are various options available to the doctor for heart valve reconstruction:

• the valve opening can be enlarged by removing tissue,
• Deposits in the area of the heart valve can be removed,
• Ligaments that control the leaflet valves can be repaired and, for example, reconnected to the heart valve.

It is also possible to strengthen the base of the valve (annulus) by adding tissue or applying an annulus ligament.

Once the doctor has reconstructed the heart valve, the patient is disconnected from the heart-lung machine. The heart beats independently again and the surgical wounds of the heart valve reconstruction are sutured.

This is followed by a few days in the intensive care unit, where the patient is monitored. This allows the doctors to detect any complications more quickly once the heart valve reconstruction has been completed.

The human heart © Peter Hermes Furian | AdobeStock

Minimally invasive heart valve reconstruction

In some cases, it is possible to perform a heart valve reconstruction on the beating heart. The surgeon uses a minimally invasive procedure to gain access to the heart and the damaged heart valve.

Mitral valve reconstruction is particularly suitable for minimally invasive heart valve reconstruction.

The surgeon makes incisions around five to six centimetres long in the right rib cage along the sternum. It is not necessary to cut through the sternum for minimally invasive heart valve reconstruction.

Minimally invasive surgery can also be used for aortic valve replacement whenever possible. The sternum is only cut in the upper area and only partially. The incision length for the procedure has thus been reduced from 20 to 30 centimetres to less than eight centimetres.

The minimally invasive procedure primarily reduces

• pain after heart valve reconstruction,
• scarring and
• the recovery time.

Above all, this method offers considerable improvements in terms of wound healing. Wound healing disorders are avoided. As a result, the surgical scar heals faster than with conventional heart valve reconstruction. Due to the reduced strain on the sternum, the patient feels less pain. This makes breathing easier.

Nowadays, the minimally invasive method is being used more and more frequently precisely because of these advantages. In Germany, however, this form of heart surgery is only available in a few selected heart centers.

Heart valve reconstruction of the mitral valve

One of the most common causes of mitral valve insufficiency is the perforation of the posterior mitral leaflet. In this case, the chordae tendineae that control the leaflet are torn. As a result, the connection between the heart valve and the papillary muscles, which control the valve function, is missing. The papillary muscles are always located below the heart valve and originate from the muscle of the respective ventricle.

When the heart beats, the ventricular muscles contract, as do the papillary muscles. This causes the leaflet valves to open and close again after the blood has been ejected.

A leaky mitral valve can be repaired using various state-of-the-art techniques and depending on the severity of the valve damage.

• depending on the severity of the valve damage and
• the quality of the tissue

sufficiently well.

In all surgical methods, the heart valve must be stabilized using a metal ring. This ring keeps the valve leaflets open and ensures that they can be closed properly. This prevents the backflow of blood (shuttle blood).

Overstretched or torn tendon sutures are routinely attached to the papillary muscle using prefabricated Gore-Tex sutures. At the same time, the punctured leaflet of the flap is sutured to prevent repeated punctures. These Gore-Tex sutures completely take over the function of the previous tendon sutures, restoring the original valve function.

It is much rarer for parts or the entire anterior mitral valve leaflet to be sutured through, which also leads to mitral valve insufficiency. The new method of chordal suture replacement has the great advantage that the affected leaflet can be reattached over a large area.

If heart valve reconstruction is not possible in this way, the tried and tested Carpentier procedure can be used as an alternative. Here, the affected segment is cut away and the remains of the valve parts are sutured together. This results in a smaller but still functional posterior mitral valve leaflet.

A "double-orifice" technique, named after the Italian heart surgeon Alfieri, is mainly used in very difficult special cases. The surgeon sutures the anterior and posterior leaflets together, linking them over a short distance so that they open and close together.

In addition, a plastic ring(annuloplasty ring) is routinely inserted. This surrounds the actual valve after the heart valve reconstruction and reduces the size of the inserted valve ring.

The plastic ring is very important to ensure that the heart valve reconstruction is successful in the long term. The use of an annuloplasty ring requires precautionary blood thinning with Marcumar for about three months after the heart valve reconstruction. After three months, the inserted ring has grown in and no longer poses a risk of embolism.

Due to the successful possibilities of heart valve reconstruction, valve replacement is only necessary in very rare cases.

Heart valve reconstruction and the statistics

Older patients in particular, who very often already suffer from heart failure, have problems with heart valve reconstruction.

If the heart chamber expands again due to the elimination of the "heart defect", the sewn-in mitral valve ring also expands. As the leaflets of the mitral valve are suspended from it, the leaflets in the middle can no longer close properly, resulting in so-called functional mitral valve insufficiency.

If the heart valve leaks again, the ventricle is again subjected to increased pressure by the swinging blood. The left ventricle becomes larger so that the heart can provide the necessary pumping capacity again. The ring eventually wears out and the mitral valve becomes more and more leaky.

Since the blood supply to the heart muscle reaches its limits as the heart gets bigger, the heart beats comparatively weaker and weaker. The pumping capacity decreases. The patient suffers from

• rapid exhaustion,
• shortness of breath and
• cardiac arrhythmia

disturbances.

A complete replacement of the mitral valve is only necessary if the heart valve is severely calcified or destroyed due to inflammation.

According to statistics from the German Society for Thoracic, Cardiac and Vascular Surgery (DGTHG), around 5,500 patients underwent mitral valve surgery in all German heart centers in 2012.

Of these, 3,600 underwent heart valve reconstruction, 60% of which were performed using minimally invasive procedures. The mortality rate for mitral valve insufficiency halved between 2000 and 2012 thanks to heart valve reconstruction.

Germany is an international leader in the quantity and quality of heart valve reconstructions. Early surgery and heart valve reconstruction can also increase the quality of life and life expectancy of those affected.

Percutaneous clip implantation for inoperable patients

The surgical risk of heart valve reconstruction increases

• in the case of advanced mitral valve insufficiency and
• with concomitant age-related illnesses

very significantly. For such patients, doctors currently favor the minimally invasive percutaneous implantation of a mitral valve clip.

This is a catheter-based heart valve reconstruction procedure in which a clip is inserted into the left atrium. This clip can be used to staple the two valve leaflets together and thus restore function.

The randomized EVEREST II trial compared mitral valve clip implantation with standard surgery. It provided clarity as to which method would achieve the better results and when. The EVEREST II study examined 279 patients with low-threshold severity of heart valve insufficiency.

One group underwent open surgery, the other percutaneous heart valve reconstruction of the mitral valve using a clip. In 20% of the subjects who had received a mitral clip, the valve insufficiency worsened over the course of 6 months. In contrast, 80 % showed a good result that remained stable in the long term.

Overall, it was shown that the percutaneous procedure for heart valve reconstruction has a lower risk. However, open surgery is significantly more efficient and therefore the superior procedure for such patients.

These study results have had a lasting impact on the surgical landscape for mitral valve insufficiency in Germany. Today, patients in poor health are predominantly treated with the percutaneous method if they have a high risk of complications.

Conclusion on heart valve reconstruction

Mitral valve insufficiency is the second most common heart valve defect in adult Germans.

The treatment of choice is heart valve reconstruction. Significant progress has been made in recent years in the field of minimally invasive heart valve reconstruction . This surgical method offers significant advantages in terms of

• the complication rate
• the healing process and
• and pain avoidance after the operation.

At the same time, new catheter-based treatment methods are being developed and tested. These include, for example, percutaneous mitral valve reconstruction by inserting a mitral clip. This procedure has been medically evaluated in studies and tested for its broad applicability.

Heart valve reconstruction is more favored than heart valve replacement. In Germany, more than 50 % of all mitral valve damage is now treated with valve-preserving heart valve reconstruction.