>Would they regenerate after the skull was put back in place? I had EXACTLY that question after responding to your earlier comment. My best guess: I think they would regenerate. But I suspect that would depend on the age of the patient, with regeneration capability (if it exists) decreasing with age. >Are there other connections -such as the recently discovered lymphatic vessels - that are severed during craniotomies? I hadn't seen the Atlantic piece so I read it carefully. The article's writer (not the scientist he interviewed) wrote "The lymph vessels probably escaped detection because they're inside a thick membrane, the dura mater, which is the consistency of leather. They run alongside blood vessels that are much larger, and on MRI the signal that creates the images is dominated by the blood vessels." Reading that, I thought that these newly discovered lymphatic vessels were not connected at all to the skull. But further along in the article: "It now seems clear that there is a third pathway through which byproducts get out of the brain — and it may be the most important — through these specialized vessels in the dura mater.'Looking back, those other two really seem insufficient,' said Reich." Reich is the lead scientist whose paper is cited in the Atlantic article. Since the skull-dura connections just discovered and described in my OP had not, as far as I can tell, been known previously (i.e., in 2017 when Reich's paper appeared), I'd have to again plead uncertainty and ignorance. Lymphatic connections between bone and dura — or between bone and any other structure in the body — that's outside my knowledge and expertise. >I guess the bigger question I have is what are the repercussions/downsides of removing large portions of the skull temporarily? It's been done since Pharaonic-era Egypt, without apparent repercussions/downsides. In my experience of having anesthetized patients for an estimated 500-1,000 craniotomies with bone flap removal over 38 years of practice, I can't say I've ever noticed problems (other than post-op infection or CSF leakage). Consider also that many patients never have the bone flap replaced but instead have a metal plate applied over the opening in the skull, which they then live with without apparent sequelae (other than TSA kerfuffles when the airport metal detector goes berserk) for the rest of their lives.