Does the size of unilateral decompressive craniectomy impact clinical outcomes in patients with intracranial mass effect after severe traumatic brain injury?

Objective: Decompressive craniectomy (DC) is one of the treatment modalities in severe traumatic brain injury (TBI), however, there was a lack of evidence for optimal craniectomy size. The authors aimed to investigate optimal DC size and analyze clinical outcome according to craniectomy size. Methods: We retrospectively reviewed the medical data of 87 patients with a space occupying lesion following TBI who underwent unilateral DC. Craniectomy size was measured by anterior-posterior (AP) diameter and surface estimate (SE). Mortality, clinical outcome, and complications were collected and analyzed according to craniectomy size. Results: Nineteen patients (21.8%) died and 35 patients (40.2%) had a favorable outcome at last follow-up (a mean duration, 30.3±39.4 months; range, 0.2-132.6 months). Receiver operating curve analyses identified AP diameter more than 12.5 cm (area under the curve [AUC]=0.740; p=0.002) and SE more than 98.0 cm2 (AUC=0.752; p=0.001) as cut-off values for survival, and AP diameter more than 13.4 cm (AUC=0.650; p=0.018) and SE more than 107.3 cm2 (AUC=0.685; p=0.003) for favorable outcome. Large craniectomy resulted in a significantly lower mortality rate and a higher rate of favorable outcome than small craniectomy (p=0.005 and p=0.014, respectively). However, procedure related bleeding occurred more frequently in the large craniectomy group (p=0.044). Conclusion: Unilateral DC size is associated with clinical outcome of patients with a space occupying lesion following severe TBI. Large craniectomy is needed for survival and favorable outcome.