Burr-Hole Evacuation of Chronic Subdural Hematoma: Biophysically and Evidence-Based Technique Improvement.

Chronic subdural hematoma (CSDH) is one of the most common neurosurgical conditions. Despite ongoing efforts, recurrence and reoperation rates after surgical treatment remain high. We synthesize scientific evidence on the treatment of CSDH with biophysical principles and then propose a simple and effective surgical technique aiming to reduce the recurrence rate. Under local anesthesia, one burr hole is placed in the area above the maximum hematoma thickness. One drain is inserted into the dorsal direction to the deepest point of the hematoma cavity, and a second drain is inserted frontally into the highest point. Next, saline is gently instilled to the dorsal drain to eliminate air from the hematoma cavity through the frontal drain. Once saline has filled the frontal drain, the frontal drain is removed. The dorsal drain is left in situ for 48 h, and the pressure within the cavity may be adapted hydrostatically. We implemented evidence-based conclusions of previous studies and modified the classical burr-hole technique to reduce the recurrence rate. As a result, we developed a straightforward surgical procedure that is possible to perform under local anesthesia, suitable for everyday practice in rural and remote areas while working with limited resources. The novelty of this technique is in the purposeful reduction of postoperative pneumocephalus, a known independent factor of recurrence. Subdural air is eliminated during surgery using a two-drain system. Safety and efficacy of the technique need to be evaluated in future clinical trials.