Blood vessels have branches. If you seal off one branch the blood still flows to the tissues through other branches. It’s like turning off the kitchen tap in your house — water can still flow to the bathroom sink or shower.

For closure of superficial skin wounds, sure, but not so great for arteries.

Surgeon here: You wouldn’t want to connect a major artery to a major vein — that would result in high pressure oxygenated blood pouring rapidly into the vein, raising pressure in the venous system and wasting oxygen. For large blood vessels we tie them off with ligatures (surgical thread, basically) or clip them shut with metal or plastic clips. Bleeding from smaller vessels is handled with cautery, usually electrocautery or sometimes ultrasonic cautery.

Spyderco SharpMaker. Works well for serrated blades as well as a conventional edge.