Give me the skinny on heart surgery.
Sooooo, how exactly do they remove a heart and replace it and keep the blood flowing properly. Machines? connect one vein at a time to it?
Is it true the heart stops beating and is removed for an entire 6 minutes?
Surgeons, please tell me how this works.
They use a heart-lung machine. Plenty of info on it at that link. First used successfully on a human in 1953 so it’s been around awhile.
Of occurs it depends on the surgery. Most heart surgery doesn’t require the heart to be removed.
The heart is still stopped of course, and in the case of complicated surgery like transplants it can be stopped for several hours, which makes “an entire 6 minutes” seem pretty paltry.
And like the Whack-a-Mole said, the solution is a machine that takes over the functions of the heart.
The people who run the machines, perfusionists, do nothing else. It’s their specialty; that’s all they do in the operating room.
There is also a type of surgery where the patient’s body temp is lowered to an extremely low temperature, like 70F or even lower, basically inducing an artificial state of hypothermia. Then the heart can be stopped for up to 30 minutes, without any brain damage (hopefully) due to the body’s natural hibernation reflex. It’s risky and only used in extreme cases, like brain surgery where the blood flow must be stopped completely.
(I thought it was called “cryosurgery,” but according to Google that term refers to something completely different…can anyone help me out here?)
When a patient requires cardio-pulmonary by-pass, ( the heart-lung machine) blood flow is diverted through the machine, where it is oxygenated. The heart no longer pumps blood. The surgeon cools and stops the heart, to allow him access to whatever area he needs to work on.
The time the heart is stopped, called arrest time, is less relevant than “cross clamp time” which is the time the major vessels were clamped, going on and off by-pass. Its critical to the patient’s future quality of life that this time be as short as possible.
That’s not to say that a prolonged pump time doesn’t have its own set if complications, it does, but cross-clamping the aorta for longer than a few minutes can mean a life on dialysis, or worse.
A form of cardiac by-pass is used in the critical care setting too. The process is called ECMO Extra-Corporeal Membrane Oxygenation. (extra-coporeal means outside the body.) I don’t believe its used outside pediatrics, and then, only rarely.
Its used mainly for premature infants whose lungs are under-developed, and merconium aspirations in newborns. ECMO can go for several days, although, the chances of major complications increase each day.
Can you tell me why? Does the lack of bloodlfow damage the kidenys somehow?
Also can you explain what cross clamping actually is.
If you didn’t want your brains picked you shouldn’t have come here. 
Hypothermic surgery. Someone in this area is working on what amounts to antifreeze for use in “profound” hypothermic surgery done at near-freezing temperatures so the heart can be stopped entirely. (It’s difficult to repair say, an aortic aneurism with the heart pumping blood.)