*In the following text I’m gonna try to explain the subject a bit to make the question accessible to those who don’t have any kind of knowledge about this, and to clarify my points to those who do know what im talking about (I apologize, it’s long, but this is not an easy problem lol):*
So every single organ and body part is fed with a constant stream of blood by at least one major artery and one major vein.
What leaves me confused is, they obviously cannot just sew the vessels closed because arteries are like insanely pressurized and the venous system relies on that small bit of pressure that is left from the arteries to help push the blood back up towards the heart. If they just took away the organ/limb and cut the artery and the vein and sewed them shut the pressure in the artery would cause it to burst and the closed vein would have no new imputs of blood to push the rest up, resulting in stagnant blood from the vein and a massive internal bleeding from the artery and the patient is dead.
Also they can’t even remove the whole artery and vein cause:
a) every major artery comes from a huge artery that runs through the center of your body called the Aorta, which is like an inch thick and carries *insanely* pressurized blood. You would therefore have to go up to the Aorta to eventually be able to cut off the artery from its beginning to avoid pressurized blood going into it in the first place, but any rupture or cut of that proportions in the Aorta would definitely cause a massive bleeding. Same thing with veins, every major vein ends up in two *gigantic* veins called the Caval Vein and the Portal Vein, that would most likely have the same catastrophic and very deadly outcome.
and b) each of those arteries and veins feeds a ton of other stuff and organs and tissues along its way to its primary organ, which would all go necrotic and cause the patient’s death.
After considering all this I thought the only logical solution would have to be to take the cut end of the artery and the cut end of the vein and sew them together, so that the blood from the artery just bypasses the missing organ and goes directly into the vein, but this carries a major problem: pressure.
Arteries are literally made to withstand the pressure the blood has after being forcefully squished out of the heart, but veins are not, as when blood gets into them it’s not pressurized anymore. This happens thanks to the capillaries: to go from an artery to a vein blood has to run through a huge net of tiny little vases that actually feed the tissues and that slow down the blood, being so narrow that blood cells can barely squeeze into them and when blood comes out of them it’s not pressurized anymore.
Veins are actually really elastic cause they have to constantly adjust to the volume of blood that is moving in your body: the most bloode you use, the more the venous pressure goes up, the more the venous system gets bigger in volume.
Therefore, attaching the pressurized artery to the very elastic vein would be like filling a big ass elastic balloon with blood from a fire hose, again eventually causing rupture and internal bleeding and killing the patient.
So people who do know the answer, please, I beg you, enlighten me cause I can’t live without knowing this anymore lmao
In: Biology
It really is a matter of just cutting the arteries and veins at the point they are entering the organ and sewing them shut (called “ligating”). You’ve got a few things right, but a few other misconceptions that I think are causing you to overthink this. Arteries are not “insanely pressurized”, but even if they were, closing one off is not going to have much effect. If you think of it as plumbing, the blood will just flow through all of the other arteries instead of through the now dead end one. Veins are also not pressurized by the heart. Capillaries are so small, that the veins don’t ever “feel” the pressure of the heart pumping. You mention that veins are elastic, and arteries are too to some degree. This allows them to respond to any (small) increase in pressure by suddenly having roughly the same amount of blood circulating through a slightly smaller plumbing system when you tie off an artery.
source: am surgeon
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