Reoperations after surgery for acute subdural hematoma: reasons, risk factors, and effects.

To analyze the reasons and patient-related and injury-related risk factors for reoperation after surgery for acute subdural hematoma (SDH) and the effects of reoperation on treatment outcome. Among adult patients operated on for acute SDH between 2013 and 2017, patients reoperated within 14 days after the primary surgery were identified. In all patients, parameters were identified that related to the patient (age, anticoagulation, antiplatelet, and antiepileptic treatment, and alcohol intoxication), trauma (Glasgow Coma Score, SDH thickness, midline shift, midline shift /hematoma thickness rate, other surgical lesion, primary surgery-trephination, craniotomy, or decompressive craniotomy), and Glasgow Outcome Score (GOS). The reasons for reoperation and intervals between primary surgery and reoperation were studied. Of 86 investigated patients, 24 patients were reoperated (27.9%), with a median interval of 2 days between primary surgery and reoperation. No significant differences in patients and injury-related factors were found between reoperated and non-reoperated patients. The rate of primary craniectomies was higher in non-reoperated patients (P = 0.066). The main indications for reoperation were recurrent /significant residual SDH (10 patients), contralateral SDH (5 patients), and expansive intracerebral hematoma or contusion (5 patients). The final median GOS was 3 in non-reoperated and 1.5 in reoperated patients, with good outcomes in 41.2% of non-reoperated and 16.7% of reoperated patients. Reoperation after acute SDH surgery is associated with a significantly worse prognosis. Recurrent /significant residual SDH and contralateral SDH are the most frequently found reasons for reoperation. None of the analyzed parameters were significant reoperation predictors.