Burr Hole Evacuation is a common procedure to treat chronic subdural haematoma. Small holes are drilled into the skull and membrane surrounding the brain. The liquid haematoma is then drained and washed out. One of the most common risks of this procedure is reaccumulation where there is ongoing bleeding of the products of the bleed which can then require further surgery.
The best way to minimise the risk of this is to place a subdural drain which involves passing a tube int the subdural space between the brain and the dura so as to drain further haematoma. However, this is a “blind procedure” and, as such, exposes the patient to further risks, such as inserting the drain at the wrong angle.
Inserting the drain deep into the brain is something the operating surgeon must be vigilant for. A misplaced drain can cause cognitive and functional complications and as such, If it is not clear, at the start of drain insertion, that the drain could not be placed safely, then this should be abandoned or the process of drain placement changed so as to allow safe passage.