In the clinical practice of neurosurgery, auditory neuroma is a common benign tumor because of its deep location, at the angle of the pontocerebellar angle, surrounded by important structures such as the brainstem (pontocerebellum), cerebellum, trigeminal nerve, facial auditory nerve, posterior group of cranial nerves (5th-12th cranial nerves) and vertebral artery, basilar artery, and rock vein, so the possible complications resulting from surgery in this area are basically related to the damage of the above structures affecting Therefore, the possible complications of surgery in this area are basically related to the damage of the above mentioned structures affecting their functions. The common tumors in the pontocerebellar horn are auditory neuroma, meningioma and cholesteatoma (epithelioid cyst), etc. The surgical complications in this area are basically similar, so here is a brief description of some complications that may be encountered in surgery, taking auditory neuroma as an example, for your reference (other tumors near this area, such as cerebellar and brainstem gliomas, can also be referred to this article). I. Intraoperative complications 1. Larger arterial vascular injury and bleeding: Removal of tumor inevitably requires more or less bleeding during surgery, but sometimes injury to large blood vessels around the tumor, such as basilar artery, vertebral artery or its larger branches, will cause more intraoperative bleeding and lead to unclear surgical field, and in the process of hemostasis, it is easy to further damage other structures such as brainstem or nerves around the tumor, causing serious consequences. If the bleeding volume is large, it will cause shock. As most of them are microsurgery nowadays, the incidence of this kind of hemorrhage is very low. 2. Brainstem injury leads to heart rate and blood pressure: brainstem is the center of life, in charge of respiration, blood pressure and heart rate, and is also the origin of cranial nerves and the center of innervation of contralateral limb movement. When separating the tumor and brainstem border during surgery, the brainstem may be injured, resulting in rapid drop or rise of blood pressure/slow or fast heart rate during surgery, at this time, the surgeon can only suspend the surgery and wait for the blood pressure and heart rate to recover before continuing the surgery carefully. In rare cases, it is difficult to recover the heart rate and blood pressure during the operation, and the life is in danger! 3. Cerebellar contusion and brain swelling: During surgery, the cerebellum needs to be stretched medially to expose the tumor, sometimes there will be cerebellar contusion and bleeding/brain swelling, which will affect the exposure and resection of the tumor during surgery. A few patients may develop cerebellar ataxia after surgery, such as unstable walking/inflexible fingers, etc. 4. Distal septal hematoma: As the tumor is removed, the volume is gradually reduced and the intracranial pressure will be lowered, so in rare cases, there will be intracranial hemorrhage due to the displacement of the distal septal part of the surgery due to the lowered intracranial pressure! The incidence is very low, but once it occurs, it will be very difficult to deal with! On the one hand, the tumor at the surgical site has not been removed, on the other hand, other parts of the skull are bleeding and compressing the brain tissue towards the surgical site, making the space at the surgical site smaller and smaller, making it impossible to continue the surgery! The surgeon has to hastily stop the ongoing surgery (sometimes even the hemostasis cannot be stopped satisfactorily), urgently close the cranium, urgently review the cranial CT, find the distant bleeding site, then enter the operating room to remove the distant hematoma first, and then re-enter from the original approach to continue the tumor surgery! Therefore, this situation is very passive and tricky! Although the surgeon will take measures (such as trying to avoid rapid intracranial pressure drop intraoperatively) to prevent it, it will still happen in very few patients. 5. Cranial nerve injury, especially facial nerve injury (facial palsy): Because the pontocerebellar angle and the nearby area where the tumor is located, is the origin of the 5th-12th pairs of cranial nerves. The tumor is closely related to the facial auditory nerve and trigeminal abducens nerve and the posterior group of cranial nerves, and there may be different degrees of injury intraoperatively, especially to the facial nerve. Facial nerve injury has no serious consequences appearing intraoperatively, but postoperatively there is obvious facial paralysis, which affects the appearance! Second, postoperative complications 1, postoperative bleeding again surgery: is a very urgent and dangerous postoperative complication, and one of the important causes of death from auditory neuroma! Post-operative intracranial hemorrhage is often urgent and requires emergency surgery, and some patients may not even have time to operate again. Hemorrhage can occur at the surgical site or at a distant surgical site, but the former is more dangerous because the hematoma is close to the brainstem and can easily cause life-threatening respiratory arrest. In case of respiratory arrest, the patient should be extubated urgently and sent directly to the operating room or to the operating room directly after CT. Although the surgeon has stopped the bleeding exactly intraoperatively, there is still a chance that bleeding will occur postoperatively and the exact cause of bleeding is difficult to identify exactly. Patients with hypertension/diabetes/hyperlipidemia/vascular sclerosis or rapid fluctuations in blood pressure after surgery have a greater chance of postoperative bleeding, which is most likely to occur on the same day after surgery, or within 3 days after surgery. 2, secondary brainstem injury: postoperative rebleeding compressing the brainstem (as mentioned above) or brainstem edema or cerebellar edema compressing the brainstem, resulting in secondary brainstem injury, which may lead to hemiplegia/coma/unstable breathing and blood pressure in severe cases, some need to perform tracheotomy, and some need to apply ventilator-assisted breathing, which is a serious complication. 3. Hydrocephalus: obstructed cerebrospinal fluid circulation due to cerebellar edema may cause obstructive hydrocephalus, and also traffic hydrocephalus due to impaired absorption of cerebrospinal fluid after surgery. The former often appears several days after surgery and requires emergency external ventricular drainage, and if the edema disappears and the external drainage is removed, there is still hydrocephalus, then internal drainage of hydrocephalus (mostly ventriculoperitoneal drainage) needs to be performed again; the latter mostly appears 2 weeks after surgery The latter mostly appears 2 weeks after surgery, and in some cases even several months after surgery, internal drainage of hydrocephalus can be performed directly. If delayed, the condition may change abruptly to form brain herniation and endanger life. 4. Facial palsy: It is the most common complication of postoperative auditory neuroma, manifested as incomplete closure of the mouth and eyes, which affects the appearance! Even if the facial nerve is preserved intraoperatively, it is still difficult to avoid postoperative facial palsy of different degrees, because the facial nerve is preserved anatomically, but the function may be impaired. Some patients have difficulty in accepting facial palsy and propose to partially remove the tumor to preserve the facial nerve, and then perform gamma knife treatment for the residual tumor, but even this cannot absolutely guarantee that the facial nerve is not damaged during surgery, because the intraoperative situation is very variable, and sometimes the tumor is rich in blood supply, so it is difficult to stop the operation in time, and the tumor has to be removed more or even completely, so that facial palsy may occur after surgery; furthermore, even if the tumor is partially removed as desired The residual tumor can also be treated with gamma knife, but the residual tumor is not eradicated, still in the skull, need long-term review, most of them can be controlled for a long time, but there are still some tumors grow up and operate again, the second operation to protect the facial nerve is more difficult, because there are adhesions of the first operation, there is also the possibility of increasing adhesions after gamma knife. The danger of facial palsy does not lie in affecting the appearance, but in the fact that the eyes are prone to infection and inflammation due to incomplete closure, and in serious cases, corneal ulcers and perforations. Therefore, if there is incomplete eyelid closure in severe facial palsy, timely measures should be taken to protect the cornea, and eyelid suturing should be performed if necessary! There are many comprehensive rehabilitation treatments for the sequelae of facial palsy, but it is basically difficult to heal. 5. Hoarseness/choking and coughing: It is caused by damage to the posterior group of cranial nerves, choking and coughing after surgery, requiring a gastric tube for feeding, which can usually be removed 2 weeks to 3 months after surgery, and can be fed normally by relying on the compensation of the contralateral nerve. Hoarseness is often more difficult to improve. 6. Cerebellar ataxia: walking instability and finger inflexibility are caused by cerebellar damage. Rehabilitation exercises are needed after surgery, and most of them will improve to varying degrees. A small number of pediatric patients do not speak, call out, do not eat or drink, or irritability after surgery, which may be a manifestation of postoperative mutism, which is also related to the damage to the cerebellum, and most of the symptoms will gradually improve. 7. Infection: including intracranial infection or pulmonary infection/urinary infection, some need to perform lumbar puncture for cerebrospinal fluid drainage, and some need tracheotomy for sputum aspiration. Pulmonary infections are more likely to occur in elderly patients/pre-operative long-term smokers. In case of prolonged postoperative coma (e.g. brainstem injury/postoperative hemorrhage reoperation), pulmonary infection is difficult to avoid and tracheotomy should be performed early. After reading the above, patients should not be afraid that not every auditory neuroma surgery will definitely have the above complications! What is described here is a summary of common complications, and each attending surgeon will do his best and put his utmost effort into each case of life entrusted and trusted to minimize the occurrence of various complications as much as possible.