system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How are surgeons able to reattach digits/limbs that have severed nerves and vessels?

I wouldn’t think one could put such small structures back together in a way that functions.
gpt
simple answer:

start with the smallest blood vessels to re-establish blood flow to severed limb. from vessels you scale in size to tissues, veins, ligaments, muscles, etc (not size ordered) then hope that the replantation is not rejected by the body.