Evaluating the optimal number of burr-holes for treating chronic subdural haematomas: good results from a single burr-hole?

Introduction. Chronic subdural haematomas (cSDH) are one of the most common types of traumatic intracranial lesion. Burr--holecraniostomy followed by closed-system drainage has become the treatment of choice. However, there is no definitive indication as to the number of burr-holes needed. Our aim was to to assess clinical and radiological outcomes taking into account the number of burr-holes made. Material and methods. A retrospective single-centre-study was performed including patients treated for cSDH by performing burr-hole craniostomy from 2012 to 2018. After collecting data regarding demographics, comorbidities, and clinical and radio-logical records, haematomas were grouped depending on the number of burr-holes made (Group 1: single burr-hole; Group 2: double burr-holes). Clinical and radiological outcomes were statistically compared between groups, as well as the main com-plications. Results. After collecting 171 patients, 205 cSDHs were analysed. 173 were treated with a single burr-hole (we called these Group 1) and 32 with double burr-holes (Group 2). No differences in preoperative characteristics were found between the groups, except for diabetes mellitus and previous antiplatelet/anticoagulation treatment. No radiological differences were found regarding haematoma volume (p = 0.7) or thickness (p = 0.3). Surgical site infection (p = 0.13), recurrence (p = 0.6), acute rebleeding (p = 0.25) and mortality (p = 0.94) were assessed without evidencing statistically significant differences. At the time of hospital discharge, most patients showed a remarkable clinical improvement, regardless of the number of burr-holes made (p = 0.7). Conclusions. This study suggests that cSDH can be efficiently evacuated by a single burr-hole craniostomy, a less invasive and shorter surgical procedure with quite good clinical outcomes and a low rate of complications.