Fig. 2.

Craniotomy for acute monitoring of pial vessels.

(A) A midsagittal incision made in the scalp. (B) Adipose tissue and periosteum were removed to expose the skull. The parietal window is drilled (C) and the piece of the bone in the middle of craniotomy is loose and can be removed with little effort (D and E). The outer layer of dura was peeled and removed while the transparent layer were left intact (F and G), in which homeostatic state of the brain is maintained. (H) Dura was ruptured, and small gap was created to expose the pial vessels and the surface of the brain.