In an Emergency: Hotlines for Assist Device Patients

Urgent questions from assist device patients or their doctors are answered around the clock:

Technical Hotline: (030) 4593-2255
Medical Hotline: (030) 4593-2288

Short- and Long-Term Systems for Circulatory Support

“HeartMate 3”, the latest implantable assist device

“Mechanical circulatory support systems” is a comprehensive term for all systems that support or replace the blood circulation. There are systems for short-term and long-term use. The short-term systems are devices external to the body. If the heart cannot recover or recovery takes longer, ventricular support systems – long-term systems – are applied. These “ventricular assist devices” (VAD) consist of a small pump that is attached by the surgeon to the patient’s heart. The pump is connected to a control unit and rechargeable batteries outside the body, which the patient carried in a small rucksack.

Most patients with a VAD can lead a broadly normal life, go to work and take part in sports. More than half of these patients are on the waiting list for a donor heart. However, the VAD is increasingly a permanent alternative to transplantation because insufficient donor organs are available or because the patient’s condition does not allow transplantation.
In some cases the patient’s heart recovers during mechanical support and the pump can be removed again.

The German Heart Center has so far implanted more than 2600 VADs, which makes its mechanical circulatory support program the largest in the world.

Types of Mechanical Circulatory Support

 

Left ventricular assist device (LVAD)

The LVAD is the form of mechanical circulatory support most often used. The pump is implanted into the lower left heart chamber and connected by a short tube with the main artery (aorta).

Right ventricular assist device (RVAD)

An RVAD is implanted into the lower right or upper right chamber and pumps “used” blood with little oxygen from the body into the pulmonary artery, through which it flows into the lung.  

Biventricular assist device (BiVAD)

It is also possible to use one pump on each side of the heart. The pumps then support the entire heart function, both the systemic and pulmonary circulation.

Total artificial heart (TAH)

The TAH replaces the human heart. The patient’s heart is removed and replaced by two mechanical pumps, which support the small and large circulation. This procedure is, however, used only rarely.

Implantation of the Support Systems

The operation for implantation of the system is carried out on the open heart or by minimally invasive surgery. The doctor decides, with the patient, which procedure is best in each individual case. For open-heart surgery the patient’s breastbone is divided and the heart is exposed. The heart-lung machine is attached to the patient and takes over the function of both these organs. A holding device is then applied to the left or right atrium (or, rarely, the ventricle), an opening is stamped in the wall of the heart chamber and the inflow cannula (tube) of the pump is introduced into the heart chamber. The outflow cannula is connected to the aorta or the pulmonary artery.

At the German Heart Center Berlin, VAD can often be implanted by minimally invasive technique, which is much gentler for the patient. The procedure is performed through two small incisions on the left and right of the chest and the breastbone needs to be only partially divided. A special method of operation developed at the German Heart Center Berlin even allows the VAD to be implanted without any division of the breastbone and without use of the heart-lung machine.

In each individual case it must be decided which method is possible.

Types of VAD

“HeartMate 3”, its position in the body and the external control and battery unit

The VAD systems most frequently implanted at the German Heart Center Berlin are the HeartWare HVAD and the Thoratec HeartMate 3. The surgeon decides, with the patient, which system is most suitable.

Heartmate 3

HeartMate 3 is currently the most modern LVAD available. The rotor of this pump system is not mechanically connected to the housing but is suspended by magnetic forces. This helps to prevent damage to the blood as it flows through the pump. The HeartMate 3 creates an artificial pulse, which can cause thromboses to form inside the device and bleeding complications in the gastrointestinal tract. The German Heart Center Berlin is one of the first hospitals to use the HeartMate 3 and has extensive experience with this system.

HeartWare HVAD

Since this system’s introduction it has been implanted over 10,000 times worldwide and has proved very reliable. At the German Heart Center Berlin it has been implanted more than 600 times.

Complications and Long-Term Results

The main complications following implantation are the formation of blood clots, due to the artificial materials of the system, and infections at the exit site of the energy and control cable. VAD patients need to take medication to thin their blood and the bandage covering the cable exit site must be changed regularly.
Many of our patients have already lived for 5 years with a VAD system, and a small number for over 10 years. Current research aims to develop systems that transfer the electrical energy to the pump inside the body without cables, so that the risk of infection can be reduced.

The VAD Program at the German Heart Center Berlin

Prof. Thomas Krabatsch, head of the assist device program at the German Heart Center Berlin (right) and his deputy, Dr. Evgenij Potapov

The success of VAD support depends on the operation being performed promptly when it is needed and on continuous aftercare.
The German Heart Center Berlin has its own VAD Outpatient Department, in which all VAD patients are followed up. In addition, our VAD hotline is available 24 hours a day to answer medical or technical questions. In 1994 a male patient at the German Heart Center Berlin from Thuringia, who had had a VAD to support his failing heart for 160 days, experienced recovery of his heart, so that it was possible to explant the device and the patient was spared a heart transplantation. This was the first such case worldwide. Since then we have explanted the VAD in over 100 cases because the patients’ hearts had recovered. Our hospital follows a special program to improve the recovery potential of the heart muscle tissue and has also developed procedures for evaluating heart muscle recovery.
So that the heart muscle is not damaged by the VAD explantation we have developed a special plug for closure of the hole left in the heart, which is manufactured individually for each patient; this makes explantation much easier.
The German Heart Center Berlin is a leading center for mechanical circulatory support (MCS) worldwide. The members of the MCS team give training seminars and are invited to hospitals all over the world to support the operating surgeons there. The team also cooperates with other German and international scientific institutions on the development of new MCS systems. At the German Heart Center Berlin numerous innovations in VAD treatment have been introduced, such as modern, less invasive surgical procedures and the minimally invasive treatment of complications. The guidelines developed at the German Heart Center Berlin are internationally recognized.
Under the leadership of Prof. Volkmar Falk, Medical Director of the German Heart Center Berlin, an international research consortium is working on the development of new artificial assist device systems.

Learn more here.