The greatest risk is the risk of hemorrhage caused by damage to the internal carotid artery during surgery, which is the greatest risk. Therefore, this is the biggest risk because the internal carotid arteries travel in the cavernous sinus bilaterally, and in the process of removing the pituitary tumor, if the pituitary tumor grows too large, it will inevitably erode the blood vessels and cause adhesions, which may occur in the process of separating the adhesions. If the pituitary tumor grows too large and causes adhesions to the surrounding nerves, the nerves may be damaged during the separation process, but this is usually not fatal. The risk of postoperative intracranial infection, because the nasal cavity is not a completely sterile environment when entering the surgery, and if the sterilization is not strict, intracranial infection may occur after the surgery, which also requires active anti-infection treatment.