A prospective multicenter cohort study was designed to compare the differences in complications with YL-1 Needle Puncture versus Bulr-hole Craniotomy (BHC) with postoperative Exhaustive Drainage strategy for patients with Chronic Subdural Hematoma.

Chronic subdural haematoma (CSDH) is a common condition in neurosurgery. It is generally considered to be a closed exudate formed by blood or blood degradation products between the dura mater and the arachnoid membrane. Its local occupying effect will compress the neighbouring brain tissues, leading to varying degrees of neurological dysfunction. In severe cases, it can lead to cerebral hernia and endanger the patient's life. Currently, the most commonly used surgical method for the treatment of chronic subdural haematoma is BHC, but many studies have found that various complications may occur after BHC. With the rapid development of neurosurgical microtechnology, Twist Drill Craniotomy (TDC) was proposed. YL-1 puncture needle technique, as a modified solution of TDC, has a short surgical time and is less traumatic to patients. In the treatment of chronic subdural haematomas, investigator's team has adopted the strategy of postoperative instillation of urokinase and adequate drainage of the haematoma. Based on this, this study intends to conduct a multicentre prospective observational cohort study of the above two treatment in order to scientifically and rigorously derive the optimal clinical treatment strategy for chronic subdural haematoma.

Inclusion Criteria:

1. Adults, male or female, 18 years ≤ age ≤ 90 years;
2. Preoperative neurological dysfunction, such as headache and dizziness, nausea and vomiting, limb numbness or weakness, unsteady walking, limb twitching, confusion, aphasia, slow response, memory loss, etc;
3. A definite diagnosis of chronic subdural hematoma by CT or MRI;
4. Signed informed consent.

Exclusion Criteria:

1. No symptoms before surgery and no obvious impact on oneself's normal life;
2. Lack of mass effect, less than 0.5 cm of midline structure shift, and no need surgery judged clinically by neurosurgeons;
3. Previous surgery for chronic subdural hematoma during the past 6 months;
4. Previous intracranial surgery for any neurological disorders but chronic subdural hematoma before
5. Existing poor medication condition or severe comorbidity so that surgery cannot be tolerated or follow-up cannot be completed
6. Combination of major systemic diseases that are expected to interfere with study implementation and follow-up observations;
7. Definite coagulation abnormalities with a high risk of bleeding (presence of one of the following three: prolongation of the prothrombin time PT or the activated partial thromboplastin time APTT by more than 10 seconds, an international normalized ratio INR greater than 3.0, and an absolute platelet value of less than 100 × 109/L);
8. Postoperative cooperation is suspected to be insufficient for follow-up for 6 months;
9. Reproductive-age women without verified negative pregnancy testing;
10. Participating in other research

Patients with CSDH recruited from the neurosurgery departments of 12 medical centers in China who had significant clinical symptoms confirmed by computed tomography or magnetic resonance imaging. Six medical centers each used BHC as well as YL-1 puncture needles for comparison.