USE OF VENTRICULAR ASSISTED DEVICES

MARIA THELMA ASUNCIONPRINCESS JOY SUSTIGUER

OVERVIEW

A ventricular assist device (VAD) is a mechanical pump that's used to support heart function and blood flow in people who have weakened hearts.

The device takes blood from a lower chamber of the heart and helps pump it to the body and vital organs, just as a healthy heart would.

TYPES OF VENTRICULAR ASSIST DEVICES

The basic types of VADs :

Left ventricular assist device (LVAD)

Right ventricular assist device (RVAD)

Biventricular assist device (BIVAD).

TWO BASIC DESIGNS

1. A transcutaneous VAD has its pump and power source located outside of the body.

2. An implantable VAD has its pump located inside of the body and its power source located outside of the body

CANDIDATES FOR THE PROCEDURE

Examples of patients who may be candidates for a VAD include:

Patients who have suffered a massive heart attack

Patients who cannot be weaned from a heart-lung bypass machine after treatment with intravenous fluids, medications, and the insertion of a balloon pump in the aorta

Patients who have an infection in the heart wall that does not respond to conventional treatment

Patients waiting for a heart transplant who are unresponsive to drug therapy and intravenous fluids

Patients with the following conditions: Cardiomyopathy Congenital heart defects Coronary artery disease Heart valve disease Life-threatening arrhythmia

PREPARATION OF THE PATIENT FOR THE PROCEDURE

Pre-implantation Informed consent is obtained from the patient with the

risks and benefits of the procedure explained in detail by cardiologist, surgeon and VAD personnel.

Patients and relatives anticipating implantation may fear it will result in a dependence on the device (and loss of independence), financial hardship, changes in body image, a loss of control and that he or she will become a burden to the family (McCafferty et al, 2002). It is critical that these issues are addressed before the implant is undertaken. The artificial heart nurse specialist takes an active role in supporting patients and carers to accept the ventricular assist device implant.

Before your VAD is implanted, it's likely you'll stay in the hospital for some time preparing for surgery. While you're in the hospital, you may have other treatments for your weakened heart or heart failure. Your doctors will make sure you're healthy enough to have surgery to implant a VAD. You may need many tests or other procedures before the surgery, including:

Echocardiogram. helps your doctor determine the pumping function of your heart, check your heart valves and help determine the cause of your heart failure. This can help your doctor decide if you're a candidate for a VAD and if there are any other treatment options available.

Chest X-ray. Your doctor uses a chest X-ray to see the size and shape of your heart and lungs.

Blood tests. Your doctor will order blood tests to see if your liver and kidneys are working properly before the surgery to implant your VAD. Your doctor might also check for other chemicals in your blood that show how well your heart is working. Blood tests are commonly used to check for diabetes, thyroid problems or symptoms of infection, which will need to be treated before you can have surgery.

Cardiac catheterization. This test checks the pressures in your heart and may be used to determine if you are a candidate for a VAD and if you may need additional devices.

THE IMPLANTATION PROCEDURE

Surgery to implant a VAD is performed by a cardiothoracic surgeon under general anesthesia. The surgery to implant a VAD is considered “open-heart surgery,” and usually takes between 4 to 6 hours.

The surgeon makes an incision down the front of the chest. The sternum (breastbone) is opened so the surgeon can access the heart.

Tubes are inserted to connect the patient to the heart-lung bypass machine. The bypass machine performs the function of the heart and lungs. By diverting blood away from the heart, the surgeon can operate on the heart much more safely.

The surgeon will then sew in the tubes which will connect to the blood pump(s) of the VAD. The locations of these tubes depend on the type of VAD being implanted. For an LVAD, the surgeon will core out a hole in the bottom of the left ventricle and insert the inflow cannula (tube) of the VAD. The cannula is secured with sutures. The outflow cannula for the LVAD is then sewn to the aorta. For an RVAD, cannula are sewn into the right atrium and pulmonary artery.

Depending on the type of VAD being implanted, the blood pump may be on the inside or outside of the body. When the pump is inside of the body, the surgeon will create a “pocket” for the pump in the abdominal wall just below the heart. If the pump is outside the body, the tubes attached to the heart will be tunneled out of the body through incisions in the skin.

Next, the surgeon attaches the tubes to the VAD pump and turns on the pump. Blood begins to flow out of the heart into the VAD. Your surgeon will adjust the settings on the pump to ensure it is appropriately supporting your heart.

Finally, the breastbone and chest incision are closed.

COMPLICATIONS:

Blood clots. As your blood moves through your VAD, blood clots may form. Blood clots can slow or block normal blood flow through your heart, which can lead to stroke or heart attack, or cause your VAD to stop working.

Bleeding. Implanting a VAD requires open-heart surgery. Having open-heart surgery can increase your risk of bleeding after your operation. Taking blood-thinning medications to reduce your risk of clotting also increases your risk of dangerous bleeding into the gastrointestinal track and the brain.

Infection. Because the power source and control unit for your VAD are outside your body and connected through a port in your skin, there's an increased risk of germs getting in the port and causing a serious infection. You and your medical team should watch for signs of infection, such as soreness or redness near the port, fluid draining from the site, or a fever.

Right heart failure. If you have an LVAD implanted, it will pump more blood from the left ventricle of your heart than what your heart might have been used to. Your right ventricle may be too weak to pump the increased amount of blood.

CARE AFTER SURGERY

Assist patient in his/her activities of daily living

Activity Level Patient might be able to return to work,

engage in hobbies and sexual activity, and drive.

Medicines Antibiotics Anti- clotting medicines

Travel . People who have VADs can fly in airplanes

and use all other forms of transportation. Nutrition and exercise

Supervised exercise also is important to give your body the strength it needs to recover.

Talk to your medical team about following a proper eating plan for recovery.

Cardiac Rehab Rehab programs include exercise training,

education on heart healthy living, and counseling to reduce stress and help you return to a more active life.

Ongoing Care After you leave the hospital, your doctor may

advise you to visit an outpatient clinic weekly for the first month. After that, you may go every other week and then every other month for a certain amount of time.

Emotional Issues and Support Talk about how you feel with your health

care team. Talking to a professional counselor also might help.