Treatment of chronic subdural hematoma by burr-hole craniostomy in adults: influence of some factors on postoperative recurrence.

BACKGROUND: The study was conducted to determine the causative factors in the postoperative recurrence (PR) of chronic subdural haematomas (CSDHs) and to evaluate the efficacy of surgery in adults enrolled in this trial.

METHODS: 99 patients with 121 CSDHs, who were operated on between January 1999 and December 2001, were studied. We evaluated the PR rate related to anamnestic, clinical, surgical and neuroradiological imaging variables. In addition, we reviewed the number and the type of repeated operations, complications of surgery and the outcomes at one, three and 12 months.

FINDINGS: 82.6% of lesions were successfully treated following the initial evacuation, and 95.9% of lesions following a second procedure. The PR rate was 14.9%. A significantly high PR rate was found to be associated with separated type, frontal base type, a midline displacement >5 mm and the presence of acute subdural clots in cranial base type on CT scans obtained within four days postsurgery. The interval from head trauma to initial surgery <60 days, the maximum width of subdural space >10 mm and massive collection of air in the subdural space tended to give a high PR rate. The PR rate associated with the homogeneous type of CSDHs was significantly low.Age, sex, cause of CSDH, anticoagulant therapy, preoperative neurological presentation, concomitant disease, variables on preoperative CT scans, and surgical factors such as the extent of the surgical procedure, use of drainage, duration and volume of drainage were not significantly associated with PR rate.

CONCLUSIONS: It is important to identify factors leading to a high or a low PR rate in the treatment of CSDHs because this may help to select appropriate surgical procedures and postoperative management to treat this condition efficiently.