Optimal bone flap size for decompressive craniectomy for refractory increased intracranial pressure in traumatic brain injury: taking the patient’s head size into account.

Background Decompressive craniectomy (DC) is a widely used treatment for refractory high intracranial pressure (ICP). While the Brain Trauma Foundation guidelines favor large DC, there remains a lack of consensus regarding the optimal size of DC in relationship to the patient's head size. The aim of this study is to determine the optimal size of DC to effectively control refractory ICP in traumatic brain injury and to measure that size with a method that takes into consideration the patient's head size. Methods All cases of unilateral DC performed to control refractory increased ICP due to cerebral edema during a 7½-year period were included. Demographic and injury-related data were collected by retrospective chart review. The patients were categorized in 2 groups: 21 patients with a “small flaps” and 9 patients with a “large flap.” Results Two groups had similar preoperative characteristics. The amount of cerebrospinal fluid drained and the doses of hyperosmolar therapy given were not different between the 2 groups. The postoperative ICP was significantly lower for the large craniectomy flap group: 13.3 mm Hg confidence interval 99% [12.7, 13.8] versus 16.9 mm Hg confidence interval 99% [16.5, 17.2] (P = 0.01), and this difference was maintained for 96 hours postoperatively. Conclusions Better ICP control was achieved in patients who underwent a large decompressive craniectomy (ratio >65%) when compared with smaller craniectomy sizes. The proposed method of measuring the craniectomy size, to our knowledge, is the first to take into account the patient's head size and can be easily measured intraoperatively.