Till 1970s, craniotomy was the most commonly used method. Burr hole trephination for chronic subdural hematoma became the most preferred method from 1980s. In 1977, Twist drill craniotomy for chronic subdural hematoma was introduced. Closed system drainage after a Burr hole (BH) or a Twist drill (TD) became the most frequently used surgical method 1).
Burr hole washout is superior interns of clinical and financial outcome; however, prospective long-term multicenter clinical studies are required to verify these findings 2).