**Chronic Subdural Hematoma Treatment With Embolization Versus Surgery Study** This study looks at treating chronic subdural hematoma (CSDH), which is a condition where blood collects on the brain's surface. The study compares two treatments: middle meningeal artery embolization (MMAE), a procedure that blocks blood flow to reduce bleeding, and conventional open surgery, which involves opening the skull to remove the blood. Participants will share their medical history, have physical exams, give blood samples, and have CT scans of their heads. They will also answer questions and either undergo MMAE or surgery. Researchers want to see if MMAE reduces the need for more surgery or deaths and check its safety compared to surgery. **Key Points:** - The study is for people aged 40-90 with specific CSDH conditions. - Participants will be randomly assigned to one of the treatments and must be ready within 72 hours. - The study involves medical tests, treatment, and sharing medical history. This study helps find safer ways to treat CSDH. Participants should be aware of the process and their role in the study.