Decompressive hemicraniectomy versus medical treatment of malignant middle cerebral artery infarction: a systematic review and meta-analysis

Objectives: To estimate evidence for decompressive hemicraniectomy (DHC) versus medical treatment effects on survival rate and favorable functional recovery among patients of malignant middle cerebral artery infarction (MMCAI) in randomized controlled trials (RCTs).

Design: The present study is a systematic review and meta-analysis of RCTs.

Setting: The MEDLINE/PubMed, EMBASE, Springer, Cochrane Collaboration database, China National Knowledge Infrastructure (CNKI) database, and Wanfang database were comprehensively searched for RCTs regarding the effects of DHC versus medical treatment among patients of MMCAI in these English and Chinese electronic databases from inception to 1 June 2019. Two reviewers independently retrieved RCTs and extracted relevant information. The methodological quality of the included trials was estimated using the Cochrane risk of bias tool. Review Manager5.3.5 software was used for statistical analyses. The statistical power of meta-analysis was estimated by Power and Precision, version 4 software.

Participants: Nine RCTs with a total of 425 patients with MMCAI, containing 210 cases in the DHC group and 215 cases in the medical treatment group, met the inclusion criteria were included. Primary outcomes were measured by survival rate, defined as modified Rankin scale (mRS) score 0-5 and favorable functional recovery as mRS score 0-3. The follow-up time of all studies was at 6-12months.

Results: First, compared with the medical treatment group, DHC was associated with a statistically significant increase survival rate (RR: 1.96, 95%CI 1.61-2.38, P < 0.00001) and favorable functional recovery (RR: 1.62, 95%CI 1.11-2.37, P = 0.01). Second, subgroup analysis: (1) Compared with the medical treatment group among patients age ≤60 years, DHC was associated with a statistically significant increase survival rate (RR = 2.20, 95%CI 1.60-3.04, P < 0.00001); (2) Compared with the medical treatment group among patients of age >60 years, DHC was also associated with a statistically significant increase survival rate (RR: 1.93, 95%CI 1.45-2.59, P < 0.00001); (3) Compared with the medical treatment group, the time of DHC was preformed within 48 h from the onset of stroke that could statistically significant increase survival rate (RR: 2.16, 95%CI 1.69-2.75, P < 0.00001). Third, sensitivity analyses that measured the results were consistent, indicating that the results were stable. Fourth, the results of statistical power analysis were ≥80%. Finally, the funnel plot of the survival rate included nine RCTs showed no remarkable publication bias.

Conclusions: Our study results indicated that DHC could increase survival rate and favorable functional recovery among patients age ≤60 or >60 years. The optimal time for DHC might be no more than 48 h from the onset of symptoms. However, due to the limitations of this research, it is necessary to design high quality, large-scale RCTs to further evaluate these findings.