Hemianesthesia, also known as intralesional anesthesia, includes lumbar and epidural anesthesia and combined lumbar and epidural anesthesia. Patients are given local anesthesia prior to puncture to reduce the pain caused by the puncture needle. The effect of intradural anesthesia is determined by whether the plane of local anesthetic diffusion in the patient’s body can meet the plane required for surgery, such as puncture failure or difficulty in puncture and uneven drug diffusion due to individual patient differences. There are three common situations: 1. the scope of anesthetic block does not meet the surgical requirements, the block is extended or biased to one side, the plane of anesthesia is too low to reach the site of the surgical incision. 2. the block is incomplete, the patient feels pain and the muscles do not relax. 3. it is completely ineffective. In addition to the reasons for failure of intralesional puncture, if the patient is in incorrect position, there is deformity in the spine, the spinal space is not clearly mapped, the patient is excessively obese, the puncture point of intralesional anesthesia is difficult to locate, etc., all of these can lead to failure of intralesional puncture.