<unk>  (crani- + -ectomy) is a neurosurgical procedure in which part of the skull is removed to allow a swelling brain room to expand without being squeezed. It is performed on victims of traumatic brain injury, stroke, Chiari Malformation, and other conditions associated with raised intracranial pressure. Use of the surgery is controversial. The procedure evolved from a primitive form of surgery known as trephining or trepanning. The older procedure, while common in prehistoric times, was deprecated in favor of other, less invasive treatments as they were developed; although it was still performed with some frequency prior to the twentieth century, its resurgence in modern form became possible only upon the development of precision cutting tools, cranial drills, and sophisticated post-operative care such as antibiotics.
Decompressive craniectomy
Craniotomy
Cerebrospinal fluid diversion
Cranioplasty
Ventriculostomy
Awake craniotomy
Ventriculotomy 
Endoscopic third ventriculostomy