*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
We ligate the blood vessels first then cut. Sometimes, based on the instruments, this is the same process.
Ex. Hysterectomy- removing the uterus
First you need to know all the points of blood supply: uterine arteries, arteries of Samson, utero ovarian ligaments.
Each of those needs to have blood supply identified and ligated/stopped.
Arteries of Sampson are small so we could use an instrument like a [Ligasure](https://www.google.com/search?q=ligasure+device&tbm=isch&ved=2ahUKEwj88KCF2Z7vAhWjSt8KHU_ZAXwQ2-cCegQIABAC&oq=ligasure&gs_lcp=ChJtb2JpbGUtZ3dzLXdpei1pbWcQARgBMgIIADICCAAyAggAMgIIADICCAA6BwgjEOoCECc6BAgAEEM6BAgjECc6BQgAELEDOgQIABADUNiIhwRY_rSHBGDXw4cEaAJwAHgAgAGDAYgB8gWSAQM2LjKYAQCgAQGwAQXAAQE&sclient=mobile-gws-wiz-img&ei=4wtFYLzzHqOV_QbPsofgBw&bih=640&biw=375&prmd=minv&rlz=1CDGOYI_enUS838US839&hl=en-US#imgrc=jU2mYVj8_tGMAM) which uses electricity to do a controlled burn and coagulate/solidify blood supply before cutting it. If the blood supply is small, we can coagulate and cut in the same place. If the blood supply is larger, such as on the utero ovarian ligaments, you may pick a spot to cut but use the Ligasure to burn/coagulate on either side of where you’re gonna cut. This gives a back stop so that, even if the point where you cut leaks, then there’s the backstop/backup points to prevent bleeding.
Now you get down to the uterine arteries which are pretty significant blood vessels. You may not want to rely on the Ligasure because the vessel is too big. In this case, you passed a suture string around the blood vessel on either side of where you want to cut, you tie a really really tight knot there. This pinches shut the blood supply, so, again you can cut in a spot that won’t bleed.
After the structure/organ has its blood supply controlled, you can remove it from its other attachment sites.
The other attachment sites with less prominent blood supply can be controlled with the electric coagulation in points or with area specific suturing.
If you are transplanting an organ, you probably don’t want to burn its attached blood vessels, so the latter example would be preferable.
Latest Answers