MATERIAL and METHODS: A retrospective analysis was performed in 74 hospitalized bilateral chronic subdural hematoma patients from January 2010 to January 2013 in Northern Jiangsu People's Hospital. Patients' gender, age, hematoma location, history of trauma, surgical approaches, the operation time, hospitalized time and follow-up three months after discharge were recorded. Prognostic indicators including symptom relief and post-hospital neuro-imaging findings were extracted. Statistical methods were conducted to evaluate surgical efficacy.

RESULTS: Both twist drill and burr-hole surgeries had a satisfying symptomatic relief (84.93%). Twist drill needs less operation time (p<0.001) and less hospitalized time (p=0.001). Maximal width of hematoma in computed tomography (CT) findings was significantly different between twist drill group and burr-hole group (p=0.026). Maximal width in CT findings was significantly associated with follow-up outcomes (p=0.021).

CONCLUSION: Twist drill is a safe and effective minimally invasive surgery, especially for elderly patients with bilateral chronic subdural hematoma and a reasonable surgical operation seems to have more significant impact upon the surgical outcome. Keywords : Bilateral, Chronic subdural hematoma, Twist drill craniotomy, Burr-hole craniotomy, Outcome