Contributor: Faisal Bakaeen, MD
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Are you scheduled for heart surgery? There has been a lot of talk about whether it is better to be on or off a heart-lung machine during heart procedures. However, I would argue that this kind of binary thinking — on-pump versus off-pump — is misguided.
Let’s take a new look at the pump — the life-saving device that mimics the critical work of the heart and lungs. I would argue that it makes the most sense to look at on-pump and off-pump as distinct tools that a surgeon may employ based on each patient’s particular case. The goal is to plan the best surgery for each person. It should be based on each person’s individual case and health history.
For example, a surgery performed off-pump may be better for some patients who are considered at higher risk for complications. This may include people who may have had a previous stroke, advanced lung disease or a calcified aorta, in which calcium deposits form on the heart’s aortic valve.
However, patients who are at low risk for reduction or impairment of cognitive function, but who have extensive heart disease, may be better treated on-pump.
For the best outcome, you want a surgeon who is knowledgeable about both on- and off-pump procedures. The use of the pump is a tool, but it is how we use it to provide the best care for the patient that is important.
What the pump does
If your surgeon recommends doing the procedure on-pump, here is how it works. First, you will receive drugs to keep your blood from clotting. Then the heart-lung bypass machine is connected to your heart. The machine takes over the heart’s pumping action as it moves blood away from the heart, and a specialist oversees the machine throughout the procedure.
The pump allows the surgeon to operate on a heart that isn’t beating and that doesn’t have blood flowing through it. During the procedure, a tube is used in the heart to drain blood to the machine. The machine removes carbon dioxide from the blood, adds oxygen, and then pumps the blood back into the body.
After the surgery is done, the surgeon restores blood flow to the heart. Usually, the heart will start beating again on its own. Sometimes mild electric shocks are used to restart the heart.
There are two important factors incorporated in the care of patients, which have improved preservation of their neurocognitive abilities with on-pump procedures. These are:
- Aortic assessment — Evaluation of the aorta to determine if and how much atherosclerosis and calcification has occurred.
- Better pump set up — As the set up for the heart lung-machine has improved, it has greatly reduced problems after heart surgery.
What is important to remember is that patients need to be evaluated by a surgeon who has all the tools available, whether on- or off-pump procedures are used. It’s critical that the surgeon uses the tools that are best for each individual patient.