Size of bone flap and bone window area may impact the outcome of decompressive craniectomy using standard bone flap.

OBJECTIVE: To verify if the size of the bone flap and the bone window area may have an impact on the outcome of decompressive craniectomy.

PATIENTS AND METHODS: From February 2012 to February 2014, 42 patients with acute intracranial hypertension were enrolled in this study. We conducted standard craniotomy and decompressive hemicraniectomy on all patients. The intracranial pressure was measured before the hemicraniectomy operation, at the time of bone flap removal, at the time of the incision of the dura mater and 24 hours after the operation.

RESULTS: Intracranial pressure readings at the time of bone flap removal, incising dura mater and 24 hours postoperation were significantly lower than the pressure measured before the operation. The highest pressure was recorded at the time of the dura mater incision followed by pressure recorded at 24 hours post-operation and at the time of bone flap removal. The lowest pressure was recorded during the preoperative period. Postoperative GOSE and GCS scores were significantly higher than those scores recorded before the operation. A positive correlation between the diameter of the bone disc and the amount of drop in pressure at 24 h post-operation was detected. Also, the bone window area showed a positive correlation with the amount of drop in pressure at 24 h post-operation.

CONCLUSIONS: The bone flap decompressive craniectomy is safe and effective, and the depressurizing range has a positive correlation with the diameter of the bone disc and the area of the bone window.