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By Fathima Riznaz Hafi
While heart transplant is the most successful curative treatment for severe heart failure, not all patients are able to undergo the surgery – this could be due to age, weakness, complications in other organs, or the unavailability of a donor heart.
An increasingly popular option to transplant is the insertion of the ‘Left Ventricular Assist Device’ (LVAD) which is a battery-operated, mechanical device designed to take over some or all of the pumping functions of the heart. The surgically implanted device serves either as a bridge to transplantation, or as an alternative to transplantation (destination therapy).
On a brief visit to Sri Lanka, Mt. Elizabeth Medical Centre Singapore Cardiothoracic Surgeon Dr. Sivathasan Cumaraswamy met members of the press and spoke about the immense benefits of this device for patients who cannot access transplant.
“Heart failure in the early stages can be treated – there are a number of ways to treat it – but as the stage progresses and the heart gets weaker, the options get more limited. When they get to the advanced heart failure stages, they can barely get out of the house, they have difficulty breathing, the legs start swelling and they are in a difficult state. The best thing we can do then is a transplant without which the result would be death but now we have an option where you we can insert a mechanical heart pump, connecting it to the left ventricle,” he said.
They offer patients the device under two circumstances:
Patients who are eligible for transplant but a donor heart is not available so they have to be put on a waiting list but when patients reach this stage chances of them surviving more than 18 months is only 10%. In such cases they use LVAD as a ‘bridge to transplant’. They put the patient on LVAD, get the blood to work, and put them on the waiting list until a suitable heart becomes available for the transplant.
When the patient is assessed for eligibility of heart transplant, generally the cut-off age is 65 years; so a patient over 65 is not suitable for transplant; then they are offered the device as a permanent form of treatment. This is referred to as ‘destination therapy’.
Similar to the heart, the LVAD is a pump. It is surgically implanted just below the heart, with one end attached to the left ventricle (chamber of the heart that pumps blood out of the heart and into the body) while the other end is attached to the aorta (body’s main artery).
Blood flows from the heart into the pump and when sensors indicate that the LVAD is full, the blood in the device is moved into the aorta.
A tube (driveline) passes from the device through the skin, connecting the pump to the external controller and power source, which post-surgery would be maintained by the patient. The external units need to be recharged at night.
An LVAD restores blood flow to a person whose heart has been weakened by heart disease. This helps relieve some symptoms, such as being constantly tired or short of breath. It maintains other organs, helps with exercise and lets the person go through cardiac rehabilitation.
After surgery there are a few risks that the patient has to be cautious of; infection is a big problem that can take place when the external devices are neglected. The patient has to therefore maintain hygiene, keeping it clean and dry with the use of an antiseptic. Another risk is blood clot – the pump is made out of titanium so when blood pumps the blood tends to clot – so they are given Aspirin and Warfarin to prevent blood clots.
“There are other risks as well which vary with each patient but we have a high success rate. In Singapore now we have treated up to 82 patients with devices and our longest surviving patient has been living for up to eight years now. She was 29 years at the time of the surgery and got married two years after transplant. Following the surgery patients can resume a normal, active life. Six years ago a 14 year old student developed heart disease. We put him on life support, treated him and now he got into university doing Aeronautical Engineering.”
Using the LVAD the patients do not get a pulse because these pumps work continuously – they don’t create a pulse.
“Normally we get a pulse when we feel the wrist because the heart beats. This pump is like a water pump – where the water just continuously flows. With a pump we cannot detect blood pressure. So we measure the blood pressure through an ultrasound. We don’t look for the normal blood pressure – we look for an average blood pressure number,” he explained.
When asked if patients are required to come back for follow-ups after the treatment, Dr. Sivathasan told Daily FT, “Most patients come back to us once in six months. If the patients live in Singapore then coming back for follow-up is not a problem but if the patient comes from abroad we work with the cardiologists from the patient’s home country – we guide the cardiologists and advise them to come to Singapore for training.”
Dr. Sivathasan visits Sri Lanka frequently and discusses matters with local cardiologists, working out protocols on how to manage patients. “There are capable heart surgeons and cardiologists here and I’ve been working with hospitals here for the last three to four years,” he said.
“If the patients can manage back home that’s fine, but it’s better for them to come back to us in Singapore because we have more experience and are more familiar on how to adjust the controller, we can check the batteries, speed of the pump and any adjustments that need to be done. Usually the pumps don’t need much care other than attending to cleanliness, which is the responsibility of the patient,” he added.
“What we are looking for in the future is – batteries that can be implanted into the body. This way there is less hassle, no need for maintenance and no risk of infection. At present, there is the inconvenience of carrying the batteries around and having to recharge them. Patients have to carry batteries in their backpack and every morning they have to check batteries. Also, with the external units they cannot swim; even when they shower they have to wrap around the device with a plastic cover so water does not go in – so it’s a process for them.
“Therefore if batteries can be put inside and can be charged from outside by a wireless charger it would make it a lot more convenient. We are hoping this sort of implant will take place in the next four to five years,” Dr. Sivathasan concluded.
