The lumbar cistern is sutured after being pulled out to prevent cerebrospinal fluid from leaking out. Lumbar cistern drainage tube inserted into cerebrospinal fluid. After extubation, if there is no suture, cerebrospinal fluid will continue to leak out, leading to infection and other adverse consequences. In the process of suture, the doctor will choose the appropriate suture method according to the specific situation to minimize trauma and bleeding, and at the same time ensure wound healing and prevent infection. Suture should be carried out under strict disinfection and aseptic conditions to avoid complications such as infection.