When I started developing the general way I wanted to tell this story, I decided that I was not at any point going to stop and explain the technicalities of how things work or the rules by which everything is governed. That stuff is boring and I think it takes away a lot of the more creative solutions your readers could come up with.
So yes, it really is a little bit more complicated than just sewing a wound shut, but I'm not going to waste a lot of time explaining why. I think it's more fun for you that way.
As an aside, this is the second to last page of the chapter. Aw yeaaaahhhh