I. Definition It is an operation of continuous drainage of cerebrospinal fluid through a lumbar puncture tube to the lumbar pool. It is one of the common diagnostic and treatment methods in the clinical work of neurosurgery. Application 1.Drainage of subarachnoid hemorrhage (whether traumatic or spontaneous SAH, it may cause cerebral vasospasm and thus lead to secondary cerebral ischemic damage, and bloody cerebrospinal fluid may easily block the arachnoid granules and cause impaired absorption of cerebrospinal fluid, thus forming traffic hydrocephalus), and early drainage is advocated in the case of low intracranial pressure. 2, the control of intracranial infection (intracranial infection is difficult to control, high mortality rate, previous treatment means are limited, now direct and effective way, can be directly through the drainage tube injection of sensitive antibiotics, while drainage of abnormal cerebrospinal fluid, there are also literature reports lumbar pool drainage technology for intracranial infection cure rate of 99%). 3.Promote the healing of cerebrospinal fluid leak (reduce the tension of the dural rupture thus promoting the healing of the rupture). 4, intraoperative use (effective in reducing intracranial pressure, revealing the operative field, the new technology of aneurysm surgery carried out in our department has greater application); 5, continuous slow and uniform drainage to reduce the chance of occipital foramen hernia, reduce the patient’s pain caused by repeated lumbar puncture; 3, contraindications with obvious intracranial occupying lesions, obstructive hydrocephalus, diffuse ICP increase or unclear ring pool, lumbar pool drainage may induce occipital foramen hernia The lumbar pool drainage is a contraindication to lumbar pool drainage. Possible problems and prevention Hypocranial pressure, treatment: the drainage rate should not exceed 15ml/h, the total daily volume should not exceed 300ml, the first day volume should not exceed 100ml, and the height of the drainage bag should not be lower than the level of the lumbar spine; the lumbar pool drainage should be closed immediately when hypocranial pressure occurs, and the head should be low and the feet should be high, and isotonic saline should be infused to improve perfusion to relieve hypocranial pressure. Intracranial infection, prevention and treatment: strict aseptic operation. Remove the drainage tube after the routine cerebrospinal fluid is normal, usually no more than 7 days, the longest is no more than 15 days, moderate use of antibiotics, monitor the routine cerebrospinal fluid and biochemistry. Injury to the spinal nerve, the spinal cord is moved to the cauda equina at the level of lumbar 1, and the tube is punctured and placed in the intervertebral space of 3, 4 or 4 or 5 as far as possible. Occipital foramen magnum herniation, treatment: strictly grasp the contraindications to do lumbar pool drainage, postoperative close monitoring of the patient’s mental pupil vital signs changes, if there are signs (the patient is not conscious, respiratory depression, heartbeat disorder) immediately close the lumbar pool drainage, emergency to give mannitol rapid sedation premise can try to inject appropriate amount of saline from the drainage tube into the spinal canal. V. Clinical experience Hundreds of patients in our department have applied the lumbar pool drainage technique, more than 95% of patients can relieve clinical symptoms and achieve the purpose of treatment, one case of intracranial infection complications, none of the patients died of complications. The continuous lumbar pool drainage technique is a minimally invasive, safe and effective treatment measure, which is easy to operate and worthy of promotion and application in the clinical work of neurosurgery.