In recent years, cranial defects have become a relatively common disorder in neurosurgery due to the high incidence of various accidents and the prevalence of various cranial diseases. The occurrence of cranial defects is very harmful. In addition to the significant threat to head safety and the potential for a range of craniosynostosis syndromes, there is also an important aesthetic impact. Due to the skull defect, many people will have obvious scalp collapse, because there is no support from the skull, the scalp will fall down according to gravity, which is very unattractive and even a bit scary, and many patients are reluctant to go out and meet people, and even have low self-esteem and depression, which is a great blow to the spirit and psychology. In addition, some people with skull defects may also have a bulging bone window, which can also cause aesthetic and psychological trauma, and may also indicate other pathologies, which need to be taken seriously. What is a bulging skull defect? There are several reasons for the bulging of cranial defects. The first is hydrocephalus, which means that the cerebrospinal fluid increases in the skull and the cranial pressure increases, which can compress some of the tissues outside the bone window; the second is an intracranial hematoma or subcutaneous effusion, which can produce a similar compression effect; the third is an intracranial penetrating deformity, which can cause the tissues to bulge outward; and there is also the abnormal growth of the brain tissue, which is more common among patients with cranial defects in children. defect, which is more common in children with cranial defects, where brain tissue in the rapid growth phase grows right out of the bone window due to the absence of cranial constraints at the defect site; in addition to these, there may be a number of other causes. What should be done about bulging skull defects? The first step is to treat the primary lesion causing the bulge. For example, if there is hydrocephalus, according to the type of hydrocephalus, shunt surgery or endoscopic fistula surgery; if there is intracranial hematoma or effusion, craniotomy is needed to remove the hematoma or the related disposal of effusion; if there is penetrating deformity or brain bulging, it also needs the related formal treatment, and so on. Then it is very important that timely cranial repair is needed.