Ventricular Assist Devices (VADS) And Mechanical Circulatory Support
What Are VADs?
Left Ventricular Assist Devices, or known more commonly as LVADs or simply VADs, are designed to take over the function of the weakened heart's left ventricle, which delivers oxygenated blood from the heart to the body. The device, which is implanted in the patient's chest, consists of an electric motor and a driveline. A tube placed in the left ventricle diverts blood from the heart to the VAD pump. The pump then propels the blood back into the aorta and out to the rest of the body. This is also known as mechanical circulatory support.
VADs can be used for two purposes:
- As a bridge to transplantation: VADs keep people with advanced heart failure going while they wait for a heart transplant
- As destination therapy: for people with advanced heart failure that are not candidates for transplant, VADs can provide ongoing treatment
Since VADs are relatively easy to use, people can leave the hospital setting with the implanted device and return to the activities of normal life.
What is VAD Surgery?
Implanting an assist device requires open-heart surgery that lasts from four to eight hours, on average. The cardiac surgeon first makes a long incision from the top-center of the chest down to the abdomen. The length of the incision depends on a person’s body size. The VAD is implanted just below the diaphragm in the abdomen. A small incision is also made in the lower abdomen to allow the device’s driveline to exit the body.
While the surgeon connects the VAD to the heart, the patient is placed on a heart-lung bypass machine, which takes over the work of the patient's heart and lungs. One tube connects the VAD pump to the left ventricle of the heart, while another returns blood from the pump to the aorta. A small electric motor within the device runs the pump.
Once the device is implanted, the driveline exiting the patient's abdomen is connected to a controller. The controller is connected in turn to the power base. After confirming that the VAD is functioning properly, surgeons take the patient off heart-lung bypass, close the incision, and bandage both the incision and the driveline exit site.
When used as a bridge-to-transplantation, VADs support heart failure patients who are too sick to wait for a donor heart to become available. The VAD allows the heart and other body systems to rest, heal, and grow stronger before the stress of transplant surgery. On average, people remain on a VAD for two to six months prior to transplantation. Many people can return home during that time with more functional capacity than they had before this surgery to address congestive heart failure.
For some people with advanced heart failure that cannot receive a heart transplant, VADs may be a better alternative for ongoing support than purely medication-based therapy.
When Should a VAD be Considered?
Reasons for people with heart failure to consider VADs include:
- Difficulty walking one block without shortness of breath despite optimal medical therapy (including an ACE inhibitor, ARB or beta blocker)
- Two hospitalizations in the past 6 months despite optimal medical therapy
- Inability to tolerate medications due to low blood pressure
- Slowly declining kidney function, as measured through blood and urine tests
The Total Artificial Heart is a device that replaces both ventricles of the heart. It is connected to a power source outside the body, and once in place, it takes over the job of pumping blood out to the lungs and the rest of the body. The device eliminates many common problems associated with heart failure and heart transplants, such as
- Malfunctioning Heart Valves: the artificial includes new, mechanical heart valves so people with valve disease no longer require open heart surgery to repair or replace malfunctioning native valves.
- Arrhythmias and Other Electrical Problems: the Total Artificial Heart eliminates the need for a pacemaker and/or defibrillator because it is not controlled by the heart’s natural electrical system.
- Donor Heart Rejection: unlike a transplanted heart, the artificial heart does is not at risk of being attacked by the body’s immune system and rejected.
Because of their larger size, most VADs require the creation of a surgical pocket for implantation. The Total Artificial Heart does not because it occupies the space of the removed failing ventricles.
How is the Total Artificial Heart Implanted?
The total artificial heart is implanted by a cardiac surgeon. The surgeon makes an incision into the chest, removes the native heart, and implants the Total Artificial Heart within the pericardial sac (a sac wrapping around the heart). The procedure lasts between five and nine hours and requires a special team of surgeons, surgical nurses, perfusionists, and specialists trained to assemble the artificial heart and check that it is working properly.
Medicines are used to stop the native heart and a heart-lung machine are employed to keep oxygenated blood moving through the patient's body during surgery. After removing the ventricles of the native heart, surgeons attach the Total Artificial Heart to its upper chambers. When the process is completed, the heart-lung machine is switched off and the artificial heart takes over, providing circulation to both the lungs and the rest of the body.
If I Need a VAD, What Are My Next Steps?
While many cardiologists can medically manage heart failure, advanced care like VADs and transplants require the experience and coordination of specialized centers. Seek out an evaluation from a multi-specialty heart failure program, like ours at Columbia, to see if you’re a good candidate for a VAD and what your options are. Our cardiac surgeons are amongst the most experienced in the world when it comes to VAD surgery, and we’re here to help you.
If you have heart disease and need help, we’re here for you. To get started today, call (212) 305-7600 or use our appointment request form.