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.