Factors that Can Help Select the Timing for Decompressive Hemicraniectomy for Malignant MCA Stroke

Surgical timing and indications for decompressive craniectomy in malignant stroke: results from a single-center retrospective analysis

PURPOSE

Acute ischemic stroke induces rapid neuronal death and time is a key factor in its treatment. Despite timely recanalization, malignant cerebral infarction can ensue, requiring decompressive surgery (DC). The ideal timing of surgery is still a matter of debate; in this study, we attempt to establish the ideal time to perform surgery in this population.

METHODS

We conducted a retrospective study of patients undergoing DC for stroke at our department. The indication for DC was based on drop in level of consciousness and standard imaging parameters. Patients were stratified according to the timing of DC in four groups: (a) "ultra-early" ≤12 h, (b) "early" >12≤24 h, (c) "timely" >24≤48 h, and (d) "late" >48 h. The primary endpoint of this study was in-house mortality, as a dependent variable from surgical timing. Secondary endpoint was modified Rankin scale at discharge.

RESULTS

In a cohort of 110 patients, the timing of surgery did not influence mortality or functional outcome (p=0.060). Patients undergoing late DC were however significantly older (p=0.008), and those undergoing ultra-early DC showed a trend towards a lower GCS at admission.

CONCLUSIONS

Our results add to the evidence supporting an extension of the time window for DC in stroke beyond 48 h. Further criteria beyond clinical and imaging signs of herniation should be considered when selecting patients for DC after stroke to identify patients who would benefit from the procedure.

External Validation and Modification of the EDEMA Score for Predicting Malignant Brain Edema After Acute Ischemic Stroke

BACKGROUND

Accurate prediction of malignant brain edema (MBE) after stroke is paramount to facilitate close monitoring and timely surgical intervention. The Enhanced Detection of Edema in Malignant Anterior Circulation Stroke (EDEMA) score was useful to predict potentially lethal malignant edema in Western populations. We aimed to validate and modify it to achieve a better predictive value for MBE in Chinese patients.

METHODS

Of ischemic stroke patients consecutively admitted in the Department of Neurology, West China Hospital between January 2010 and December 2017, we included patients with anterior circulation stroke, early signs of brain edema on computed tomography within 24 h of onset, and admission National Institutes of Health Stroke Scale (NIHSS) score ≥ 8. MBE was defined as the development of signs of herniation (including decrease in consciousness and/or anisocoria), accompanied by midline shift ≥ 5 mm on follow-up imaging. The EDEMA score consisted of five parameters: glucose, stroke history, reperfusion therapy, midline shift, and cistern effacement. We created a modified score by adding admission NIHSS score to the original EDEMA score. The discrimination of the score was assessed by the area under the receiver operating characteristics curve (AUC). Calibration was assessed by Hosmer-Lemeshow test and calibration plot. We compared the discrimination of the original and modified score by AUC, net reclassification improvement (NRI), and integrated discrimination improvement (IDI). Clinical usefulness of the two scores was compared by plotting net benefits at different threshold probabilities in the decision curve analysis.

RESULTS

Of the 478 eligible patients (mean age 67.3 years; median NIHSS score 16), 93 (19%) developed MBE. The EDEMA score showed moderate discrimination (AUC 0.72, 95% confidence interval [CI] 0.67-0.76) and good calibration (Hosmer-Lemeshow test, P = 0.77). The modified score showed an improved discriminative ability (AUC 0.80, 95% CI 0.76-0.84, P < 0.001; NRI 0.67, 95% CI 0.55-0.78, P < 0.001; IDI 0.07, 95% CI 0.06-0.09, P < 0.001). Decision curves showed that the modified score had a higher net benefit than the original score in a range of threshold probabilities lower than 60%.

CONCLUSIONS

The original EDEMA score showed an acceptable predictive value for MBE in Chinese patients. By adding the admission NIHSS score, the modified score allowed for a more accurate prediction and clinical usefulness. Further validation in large cohorts of different ethnicities is needed to confirm our findings.

Optic nerve sheath diameter change in prediction of malignant cerebral edema in ischemic stroke: an observational study

Background

In acute large anterior circulation infarct patients with large core volume, we evaluated the role of optic nerve sheath diameter (ONSD) change rates in prediction of malignant progression.

Methods

We performed a retrospective observational study including patients with anterior circulation acute ischemic stroke with large ischemic cores from January 2010 to October 2017. Primary outcome was defined as undergoing decompressive surgery or death due to severe cerebral edema, and termed malignant progression. Patients were divided into malignant progressors and nonprogressors. Malignant progression was divided into early progression that occurred before D1 CT, and late progression that occurred afterwards. Retrospective analysis of changes in mean ONSD/eyeball transverse diameter (ETD) ratio, and midline shifting (MLS) were evaluated on serial computed tomography (CT). Through analysis of CT at baseline, postprocedure, and at D1, the predictive ability of time based change in ONSD/ETD ratio in predicting malignant progression was evaluated.

Results

A total of 58 patients were included. Nineteen (32.8%) were classified as malignant; 12 early, and 7 late progressions. In analysis of CT_{postprocedure}, A 1 mm/hr. rate of change in MLS during the CT_baseline-CT_{postprocedure} time phase lead to a 6.7 fold increased odds of early malignant progression (p < 0.05). For ONSD/ETD, 1%/hr. change lead to a 1.6 fold increased odds, but this association was trending (p = 0.249). In the CT_D1, 1%/day change of ONSD/ETD in the CT_baseline-CT_D1 time phase lead to a 1.4 fold increased odds of late malignant progression (p = 0.021) while 1 mm/day rate of change in MLS lead to a 1.5 fold increased odds (p = 0.014).

Conclusions

The rate of ONSD/ETD changes compared to baseline at D1 CT can be a predictor of late malignant progression along with MLS. ONSD/ETD change rates evaluated at postprocedure did not predict early malignant progression.

Timing of Decompressive Craniectomy for Ischemic Stroke and Traumatic Brain Injury: A Review

While studies have demonstrated that decompressive craniectomy after stroke or TBI improves mortality, there is much controversy regarding when decompressive craniectomy is optimally performed. The goal of this paper is to synthesize the data regarding timing of craniectomy for malignant stroke and traumatic brain injury (TBI) based on studied time windows and clinical correlates of herniation. In stroke patients, evidence supports that early decompression performed within 24 h or before clinical signs of herniation may improve overall mortality and functional outcomes. In adult TBI patients, published results demonstrate that early decompressive craniectomy within 24 h of injury may reduce mortality and improve functional outcomes when compared to late decompressive craniectomy. In contrast to the stroke data, preliminary TBI data have demonstrated that decompressive craniectomy after radiographic signs of herniation may still lead to improved functional outcomes compared to medical management. In pediatric TBI patients, there is also evidence for better functional outcomes when treated with decompressive craniectomy, regardless of timing. More high quality data are needed, particularly that which incorporates a broader set of metrics into decision-making surrounding cranial decompression. In particular, advanced neuromonitoring and imaging technologies may be useful adjuncts in determining the optimal time for decompression in appropriate patients.