Although microvascular decompression(MVD)is a highly effective treatment, there is little pathological evidence and some aspects of its mechanism remain unclear. Therefore, when symptoms appear after surgery, it is difficult to determine the pathological condition and select the treatment method. Therefore, we recommend dividing these factors into three categories. The first is "prolonged cure." Compressed nerves may take time to regenerate; therefore, it is necessary to wait at least one year to see if they recover naturally, especially in facial spasms. The second is "uncured." Intraoperative video and postoperative imaging findings should be reviewed. If a compressed blood vessel is overlooked or inappropriately decompressed, additional surgery should be performed. The third is "true recurrence," which is the loss of fixation of compressed blood vessels and granulomatization of the Teflon. Nerve bending that occurs again due to the retraction of the trigeminal nerve is corrected by reoperation. The therapeutic effects of reoperation are particularly strong in trigeminal neuralgia. Owing to the risk of nerve damage due to adhesion dissection, it is important to carefully consider and establish good communication with patients before surgery.