Is it not necessary to repair the skull if the patient is unconscious? At the time of cranial trauma, the trauma leads to intracranial hemorrhage or brain tissue edema, and a piece of skull bone needs to be removed to expand the intracranial volume, lower the intracranial pressure and reduce the compression on the brainstem vital center, which is called debridement decompression. When the patient is stable, the removal of a large area of the skull will have a negative impact on cerebral blood flow, cerebral metabolism and cerebrospinal fluid, causing the patient to remain unconscious and even cause life-threatening abnormal brain herniation. In addition, there is a misconception that “if the patient is not awake, there is no need to repair the skull”, but here we need to emphasize that repairing the skull plays an important role in stabilizing the intracranial state, so it is necessary to repair the skull defect in time. So what are the benefits of cranial repair for brain tissue repair? When is the best time to repair? What is the best material to use? Firstly, cranial repair is beneficial to the recovery of brain function Patients with cranial defects specifically show increasingly poor motor impairment (57%), higher cognitive deficits (41%) and language function (28%). The possibility of this syndrome should be considered when the patient’s recovery process becomes slower, less responsive to the environment, or even stagnant, without any trigger. In layman’s terms, it means that the patient is becoming more and more wilted, not moving and talking as much as usual, and becoming more and more listless, which is something to be aware of. Figure 1: Effect of cranial defect on cerebrospinal fluid flow, cerebral blood flow and cerebral metabolism under the influence of atmospheric pressure. Figure 2: Significant increase in brain metabolism and improvement in brain function after cranial repair. Secondly, the timing of cranial repair When hydrocephalus and cerebral bulge complications occur after decompression surgery, the traditional treatment method is to perform ventriculo-abdominal shunt first, and then perform cranial repair after 3-6 months, which is easy to miss the best treatment period, currently the clinical use of simultaneous one-time cranial repair and ventriculo-abdominal shunt for the surgical treatment of patients with cranial defect combined with hydrocephalus after craniocerebral injury has achieved satisfactory The results are satisfactory, and the consciousness and neurological dysfunction of patients are obviously reduced. Studies have shown that patients with early cranial repair (<2 months) have a better prognosis than those with delayed repair (>3 months). In this paper, we believe that patients who undergo early cranial repair should exclude increased intracranial pressure, intracranial occupied masses, brain swelling and abnormal cerebrospinal fluid, and once intracranial pressure and other contraindications to cranial repair are excluded, early cranial repair should be performed. Third, the choice of repair material The most used artificial material is titanium mesh plate, because titanium alloy material is non-toxic, low inflammatory and allergenic, good histocompatibility, after implantation, fibroblast can grow into the microporous of titanium mesh, so that titanium mesh and tissue fuse into one, and there is a trend of calcification and ossification, which is a more ideal artificial repair material. However, titanium mesh is affected by temperature. Moreover, because of its inherent deficiencies in shaping, titanium mesh is difficult to shape perfectly in areas with large head curvatures, such as the forehead and brow arch, and may have traces of mesh after implantation, making the visual effect less favorable. PEEK (polyetheretherketone) is a special engineering plastic that looks similar to ordinary plastic, but has many advantages such as high temperature resistance, corrosion resistance, robustness, and good toughness and fatigue resistance. It is strong but flexible, the weight and texture is very close to the human skeleton, even if subjected to collisions will not appear dented or deformed, PEEK cranial repair perfect to make up for the shortcomings of titanium mesh. However, it is expensive and prone to subcutaneous fluid accumulation. Therefore, the choice of repair material should vary from person to person.