Effects of decompressive craniectomy on functional outcomes and death in poor-grade aneurysmal subarachnoid hemorrhage: a systematic review and meta-analysis

OBJECTIVE Patients with poor-grade aneurysmal subarachnoid hemorrhage (aSAH) (World Federation of Neurosurgical Societies Grade IV or V) are often considered for decompressive craniectomy (DC) as a rescue therapy for refractory intracranial hypertension. The authors performed a systematic review and meta-analysis to assess the impact of DC on functional outcome and death in patients after poor-grade aSAH. METHODS A systematic review and meta-analysis were performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Articles were identified through the Ovid Medline, Embase, Web of Science, and Cochrane Library databases from inception to October 2015. Only studies dedicated to patients with poor-grade aSAH were included. Primary outcomes were death and functional outcome assessed at any time period. Patients were grouped as having a favorable outcome (modified Rankin Scale [mRS] Scores 1-3, Glasgow Outcome Scale [GOS] Scores 4 and 5, extended Glasgow Outcome Scale [GOSE] Scores 5-8) or unfavorable outcome (mRS Scores 4-6, GOS Scores 1-3, GOSE Scores 1-4). Pooled estimates of event rates and odds ratios with 95% confidence intervals were calculated using the random-effects model. RESULTS Fifteen studies encompassing 407 patients were included in the meta-analysis (all observational cohorts). The pooled event rate for poor outcome across all studies was 61.2% (95% CI 52%-69%) and for death was 27.8% (95% CI 21%-35%) at a median of 12 months after aSAH. Primary (or early) DC resulted in a lower overall event rate for unfavorable outcome than secondary (or delayed) DC (47.5% [95% CI 31%-64%] vs 74.4% [95% CI 43%-91%], respectively). Among studies with comparison groups, there was a trend toward a reduced mortality rate 1-3 months after discharge among patients who did not undergo DC (OR 0.58 [95% CI 0.27-1.25]; p = 0.168). However, this trend was not sustained at the 1-year follow-up (OR 1.09 [95% CI 0.55-2.13]; p = 0.79). CONCLUSIONS Results of this study summarize the best evidence available in the literature for DC in patients with poor-grade aSAH. DC is associated with high rates of unfavorable outcome and death. Because of the lack of robust control groups in a majority of the studies, the effect of DC on functional outcomes versus that of other interventions for refractory intracranial hypertension is still unknown. A randomized trial is needed.