If the blockage is removed from the blood vessel, what will happen to blood flow after removal?

In general, veins that are cut can be cauterized to stop the bleeding. The very large vena cavas which are veins deep in the body are repaired with suture if cut or opened, as with the jugular veins and any other large vein.

Arteries, which are deeper and carry oxygenated blood under pressure are tied off if cut through. The larger and deeper arteries aren’t cut into randomly….only when the surgery is being done to repair one. If an artery is cut due to trauma, this requires immediate surgical attention to stop the bleeding and repair or apply a graft. If you cut yourself and the blood spurts out and won’t stop with pressure, this is probably an artery and needs ER medical attention as you will lose blood quickly.

If an artery is cut into on purpose it is done to remove or bypass a blockage. Once a graft is in place, and clamps removed, the same blood flows through the repaired artery. This is most commonly done on the abdominal aorta when necessary. While operating on a major artery, the blood is heparanized to avoid clotting.

Veins, which carry de oxygenated blood back to the heart can be cauterized because they are usually smaller and not under the blood pressure that arteries are under. If you accidentally get a cut or scratch that is only skin deep, the bleeding is from veins carrying blood that will clot within a couple of minutes or less.   Much of a Surgeon’s time is spent trying to keep blood in the blood vessels where it belongs. This wouldn’t be a problem but they insist on cutting holes in people. They apply heat, electricity and pressure to prevent blood from running over their surgical field. They also place titanium clips and loop sutures around potential bleeding vessels and cut them before they can bleed.