I. Supratentorial lesions There are various methods of dural incision for craniotomy of the cerebral hemispheres. When considering the method of dural incision, the following aspects should be noted: ① maximum exposure of the cerebral cortex; ② maximum decrease in brain tension; ③ the length of dural incision should be as short as possible; ④ the problem of acute brain tissue expansion and impaction should be considered; ⑥ it is easy to close tightly and maintain integrity; ⑦ it is easy to operate. When suturing the dura mater, the principle of suturing after the first cut and suturing after the first cut is generally followed.1 The following five common dural incision methods are analyzed: 1, “U” shaped incision method: The dural “U” shaped incision, often also called flap incision, is the most common method for cerebral hemispheric lesions. The most common method for lesions. The dura is turned to the side of the venous sinus or to the side of the skull base. In most supratentorial lesions, this method of dural dissection meets the surgical requirements and is simple to perform and easy to close tightly. In the case of high brain pressure, a reduction incision is needed to avoid brain tissue cantonment. 2.”X”-shaped incision method: This dural incision method is suitable for patients with acute intracranial hematoma and brain herniation on the screen, and star (“human”-shaped) and “+”-shaped incision methods can also be applied. The aim is to shorten the craniotomy time and to obtain the most cortical exposure and the fastest and maximum decompression of the brain tissue. This method is easy to perform and is very practical. We all know that early cranial decompression of acute subdural hematoma and active postoperative ICU monitoring are the key factors to improve prognosis, but cutting the dura in the case of severe midline shift and high dural tension may cause acute brain bulge and brain tissue entrapment, which in turn aggravates the condition and becomes one of the factors of poor prognosis. There are reports in the literature2,3 that multiple dural openings can prevent brain bulge and improve the prognosis. In addition, the second line of the “X” and “+” incision is difficult to ensure that the midpoint of the first line is cut, resulting in a misalignment of the midpoints, and the misaligned midpoints will cause distortion of the dura and high tension, which can easily cause fluid leakage. The dura mater cut in this way is repaired by “triangle” and “four-petal flower” method4, which can get the maximum decompression space without causing postoperative herniation of brain tissue incision. According to our clinical experience, the “X”-shaped dural incision is the best choice in this case. 3, double “Y” connection incision method: this dural incision method can be used in supratentorial flat surgery, and its operation is relatively simple. When cutting the dura, the middle dashed line is cut first, and the sides are extended to the bone holes, so that the most cerebral cortex can be revealed and the brain tissue can be decompressed. Because of the two “three points”, there is less chance of misalignment of the midpoint, distortion of the dura, poor suturing, and leakage of fluid when the dura is closed. In practice, we think it is also very convenient. 4. Double “T” connection stagger method: This method was introduced in 2005 by Professor Zhang Yuqi and Wang Loyalty of the Department of Neurosurgery of Beijing Tiantan Hospital in the Chinese Journal of Neurosurgery. After using this method, we believe that it is one of the methods of dural incision in supratentorial lesion surgery that is worth promoting. After the formation of the bone window, the dura is first cut in a straight line from any two opposite bone holes, and then cut at 1/3 of each end of the cut line toward the other two bone hole angles to form four mutually symmetrical dural triangle flaps. This method has the shortest dural cutting distance and allows for maximum exposure of the cerebral cortex, easy and tight dural suturing, and minimal tension after suturing. However, care should be taken not to make the two small dural triangular flaps too small when using this method of dural incision to avoid difficulties in suturing. 5.Hemilunar or arcuate incision method: It is the most commonly used dural incision method for wing point craniotomy. If the brain pressure is high, make one or two reduction incisions to the cranial vault side. If necessary, the dura is cut to the right anterior and inferior window angle to explore the lateral fissure and release the cerebrospinal fluid to reduce the cerebral pressure. The operation space of the inferior posterior cranial fossa is relatively small and the dural tension is high, so it is difficult to close the dura tightly after incision, especially when doing the suboccipital median linear craniotomy. The dural incision and suturing of cerebellar hemispheres are relatively easy, and the “X” shaped incision method is generally used. For pontocerebellar horn lesions, arc-shaped incision or “T” row incision is mostly used. However, because there are more surgical accesses for pontocerebellar horn lesions, the incision methods also vary. Here we mainly analyze the two dural incision methods for suboccipital median linear craniotomy. 1.”Y”-shaped incision method: It is a commonly used method, which is difficult to operate because of the narrow space in the posterior cranial fossa, and this method exposes the cerebral cortex to the greatest extent, and is relatively easy to operate. The problem is that the well-developed occipital sinus may be opened to cause bleeding, and the suture is often not tightly closed due to the high tension, and dural repair is needed. 2.”H”-shaped incision method: After the “U”-shaped incision of the upper dura mater, the upper and lower occipital sinuses are ligated with a No. 4 silk thread through. From the lower dural flap, avoid the occipital sinus in the middle and cut both sides of the foramen magnum. This avoids the dural venous sinuses and leaves the dura intact at the foramen magnum, which is particularly suitable for pediatric patients. The disadvantage is that it is not convenient to expose the occipital foramen, as in the case of cerebellar tonsillectomy. This method also suffers from the problem of the dura not being tightly sutured and the need for dural repair that occurs with the “Y” shaped incision. In summary, there are many dural incision methods, and the method of incision is different for different sites. The choice of which method to cut the dura is based on operability and tightness on one hand; on the other hand, it is related to the operator’s surgical habits and experience. The purpose is to bring convenience to the surgical operation and to reduce complications such as postoperative wound subcutaneous fluid and cerebrospinal fluid leakage, not to say which method is the best.