Surgical Decompression for Space-Occupying Hemispheric Infarction: A Systematic Review and Individual Patient Meta-analysis of Randomized Clinical Trials

Abstract

Importance: In patients with space-occupying hemispheric infarction, surgical decompression reduces the risk of death and increases the chance of a favorable outcome. Uncertainties, however, still remain about the benefit of this treatment for specific patient groups.

Objective: To assess whether surgical decompression for space-occupying hemispheric infarction is associated with a reduced risk of death and an increased chance of favorable outcomes, as well as whether this association is modified by patient characteristics.

Data sources: MEDLINE, Embase, the Cochrane Central Register of Controlled Trials, and the Stroke Trials Registry were searched from database inception to October 9, 2019, for English-language articles that reported on the results of randomized clinical trials of surgical decompression vs conservative treatment in patients with space-occupying hemispheric infarction.

Study selection: Published and unpublished randomized clinical trials comparing surgical decompression with medical treatment alone were selected.

Data extraction and synthesis: Patient-level data were extracted from the trial databases according to a predefined protocol and statistical analysis plan. The Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) reporting guideline and the Cochrane Collaboration's tool for assessing risk of bias were used. One-stage, mixed-effect logistic regression modeling was used for all analyses.

Main outcomes and measures: The primary outcome was a favorable outcome (modified Rankin Scale [mRS] score ≤3) at 1 year after stroke. Secondary outcomes included death, reasonable (mRS score ≤4) and excellent (mRS score ≤2) outcomes at 6 months and 1 year, and an ordinal shift analysis across all levels of the mRS. Variables for subgroup analyses were age, sex, presence of aphasia, stroke severity, time to randomization, and involved vascular territories.

Results: Data from 488 patients from 7 trials from 6 countries were available for analysis. The risk of bias was considered low to moderate for 6 studies. Surgical decompression was associated with a decreased chance of death (adjusted odds ratio, 0.16; 95% CI, 0.10-0.24) and increased chance of a favorable outcome (adjusted odds ratio, 2.95; 95% CI, 1.55-5.60), without evidence of heterogeneity of treatment effect across any of the prespecified subgroups. Too few patients were treated later than 48 hours after stroke onset to allow reliable conclusions in this subgroup, and the reported proportions of elderly patients reaching a favorable outcome differed considerably among studies.

Conclusions and relevance: The results suggest that the benefit of surgical decompression for space-occupying hemispheric infarction is consistent across a wide range of patients. The benefit of surgery after day 2 and in elderly patients remains uncertain.

Figure 1.. Scores on the Modified Rankin Scale (mRS) at 1 Year

Figure 2.. Forest Plot of Subgroups With Modified Rankin Scale Scores of 3 or Less at 1 Year

P values for heterogeneity across subgroups are shown (interaction term treatment × subgroup variable). Odds ratios (ORs) are adjusted for age, sex, and presence of aphasia (not National Institutes of Health Stroke Scale [NIHSS] score at baseline and time to randomization). All analyses were performed with a 1-stage model with random effects for the variables trial and treatment. ACA indicates anterior cerebral artery; MCA, middle cerebral artery; and PCA, posterior cerebral artery. Squares represent mean values, with the size of the squares indicating weight and horizontal lines representing 95% CIs. The diamond represents the summary mean with the points of the diamond representing the 95% CI. ^aNot recorded in the study by Zhao et al (n = 47) and missing (n = 1) in HAMLET (Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial). ^bNot recorded in DEMITUR (Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery: A Randomized Controlled Trial in a Turkish Population) (eAppendix 3 in the Supplement) (n = 151) and missing (n = 1) in the DESTINY II (Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery II) study. ^cNot recorded in the study by Slezins et al (n = 44), Decompressive Craniectomy in Malignant MCA Infarction (DECIMAL) (n = 38), and DESTINY (n = 32) and missing (n = 16) in DEMITUR.

Figure 3.. Forest Plot of Subgroups With Shift Analysis of the Modified Rankin Scale (mRS) Score

P values for heterogeneity across subgroups are shown (interaction term treatment × subgroup variable). Common odds ratios (ORs) are adjusted for age, sex, and presence of aphasia (not National Institutes of Health Stroke Scale [NIHSS] score at baseline and time to randomization). All analyses were performed with a 1-stage model with random effects for the variables’ trial and treatment. ACA indicates anterior cerebral artery; MCA, middle cerebral artery; and PCA, posterior cerebral artery. Squares represent mean values, with the size of the squares indicating weight and horizontal lines representing 95% CIs. The diamond represents the summary mean with the points of the diamond representing the 95% CI. ^aNot recorded in the study by Zhao et al (n = 47) and missing (n = 1) in HAMLET (Hemicraniectomy After Middle Cerebral Artery infarction with Life-threatening Edema Trial). ^bNot recorded in DEMITUR (Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery: A Randomized Controlled Trial in a Turkish Population) (eAppendix 3 in the Supplement) (n = 151) and missing (n = 1) in the DESTINY II (Decompressive Surgery for the Treatment of Malignant Infarction of the Middle Cerebral Artery II) study. ^cNot recorded in the study by Slezins et al (n = 44), DECIMAL (Decompressive Craniectomy in Malignant MCA Infarction) (n = 38), and DESTINY (n = 32) and missing (n = 16) in DEMITUR.