Background and Goal of Systematic Review:
The role of decompressive craniectomy (DC) in the treatment of patients with high intracranial pressure (hICP) after traumatic brain injury (TBI) is controversial. Aim of this systematic review (SR) is to summarize recent clinical evidences on DC in hICP after TBI. 
Materials and Methods:
A SR literature search of PubMed  using (brain injury) AND (DC) and (brain injury) AND (ICP) as key words of papers published between January 2011 to November 2016, has been accomplished. Only full text papers published in English and presenting original data were included. The articles were evaluated according to PRISMA recommendations and details recorded using a dedicated data extraction form. 
Results and discussion:
This SR, includes 4 studies: 2 RCTs (n= 553 patients) and 2 observational (n= 627 patients). The 2 RCTs report partially conflicting results.1,2 The DECRA trial, tested early DC for hICP management and showed a better control of ICP in DC group vs. medical therapy group (14.4 mmHg vs. 19.1 mmHg, P<0.001). Paradoxically, better ICP control was associated with higher unfavorable outcomes (GOS-E 1-4 70% vs. 51%; OR 2.21; 95% CI, 1.14 to 4.26; P=0.02) and worse functional outcome (6 months GOS-E median score, 3 vs. 4; OR 1.84; 95% confidence interval [CI], 1.05 to 3.24; P=0.03). The RESCUEicp trial, tested DC as a last tier therapy for hICP, and reported lower mortality in DC group than in control (26.9% vs. 48.9%; P <0,001). Of interest, GOS-E at 12 months, confirmed the clinical benefit associated with DC: a higher rate of patients treated with DC had higher  “upper severe disability - good recovery” at follow up than the control group(45,4% vs. 32,4%; P=0,01).
The 2 observational studies reported an association between good outcome and: age <60, early timing (DC when ICP <20 mmHg), bone flap >130 cm2, and GCS >5 before DC.3,4
Conclusions:
The benefit of DC remains controversial but recent evidence displayed positive results. Optimal timing and presence of prognostic parameters are associated with better outcome. Indiscriminate application of DC is not appropriate and possible clinical benefit deserve specific circumstances and pts selection.

Decompressive craniectomy after traumatic brain injury: a systematic review of recent evidences