Distance to Thrombus in acute middle cerebral artery stroke predicts basal ganglia infarction after mechanical thrombectomy

Delayed CTP-Derived Deep Venous Outflow: A Novel Predictor of Striatocapsular Infarction after M1 Thrombectomy

BACKGROUND AND PURPOSE

Isolated striatocapsular infarction occurs commonly in patients with ischemic stroke following M1 thrombectomy. We aimed to explore the correlation between CTP-derived parameters of deep venous outflow at presentation and subsequent striatocapsular infarction in a retrospective cohort of such patients.

MATERIALS AND METHODS

TTP and peak enhancement were measured on CTP-derived time-attenuation curves of the internal cerebral and thalamostriate veins bilaterally. The difference in TTP (ΔTTP) and the relative decrease in venous enhancement between the ischemic and normal sides were calculated. NCCT performed 24 (SD, 12) hours postthrombectomy was used to determine tissue fate in the caudate head, caudate body, lentiform nucleus, and internal capsule. Striatocapsular ischemia (striatocapsular infarction-positive) was defined as infarction and striatocapsular injury as either infarction, contrast enhancement, or hemorrhagic transformation in ≥1 of these regions. A striatocapsular ischemia score was calculated (0 = no ischemic region, 1 = 1 ischemic region, 2 = ≥2 ischemic regions).

RESULTS

One hundred sixteen patients were included in the analysis. Sixty-one patients had striatocapsular infarction (striatocapsular infarction-positive). The mean thalamostriate ΔTTP was 1.95 (SD, 1.9) seconds for patients positive for striatocapsular infarction and 0.79 (SD, 2.1) for patients negative for it (P = .010). Results were similar for striatocapsular injury. The mean thalamostriate ΔTTP was 0.79 (SD, 2.1), 1.68 (SD, 1.4), and 2.05 (SD, 2) for striatocapsular infarction scores of 0, 1, and 2, respectively (P = .030).

CONCLUSIONS

CTP-derived thalamostriate ΔTTP is an excellent surrogate marker for striatocapsular infarction in patients post-M1 thrombectomy. The novel approach of extracting venous outflow parameters from CTP has numerous potential applications and should be further explored.

Incidence, outcomes, and associated factors of isolated striatocapsular infarct after mechanical thrombectomy

OBJECTIVE

To describe baseline and procedural characteristics and clinical outcomes of isolated striatocapsular infarct (iSCI) after mechanical thrombectomy in patients with large-vessel occlusion of the anterior cerebral circulation and its clinical outcome.

METHODS

We performed a longitudinal study including all patients treated with mechanical thrombectomy at our centre between 2015 and 2017; patients were divided into 2 groups (iSCI and non-iSCI) according to whether they presented iSCI in a control CT scan at 24 hours.

RESULTS

Of the 83 patients identified, 22.9% developed an iSCI. There were no statically significant differences in baseline characteristics or in reperfusion times. Patients presenting iSCI showed better collateral circulation and better reperfusion rates in the bivariate analysis. No significant difference was observed for mortality at discharge or at 3 months, or for functional prognosis at 3 months.

CONCLUSIONS

Even if successful reperfusion is achieved, iSCI is a common sequela, independently of reperfusion time, especially in patients with good collateral circulation.

Outcome after Thrombectomy of Acute M1 and Carotid-T Occlusions with Involvement of the Corticospinal Tract in Postinterventional Imaging

OBJECTIVES

Until now, thrombectomy studies have provided little reliable information about the correlation between the infarct topography and clinical outcome of acute stroke patients with embolic large-vessel occlusions. Therefore, we aimed to analyze whether infarcts of the corticospinal tracts in the central white matter (CWM) or the internal capsule on postinterventional imaging controls are associated with poor clinical outcome after thrombectomy.

MATERIALS AND METHODS

We retrospectively analyzed imaging data from 70 patients who underwent endovascular thrombectomy for emergent middle cerebral artery or carotid-T occlusions. Inclusion criteria were postinterventional infarct demarcation in the regions of the internal capsule, caudate, lentiform nucleus, and CWM. Primary outcome was the mRS after 90 days and secondary endpoints were subgroup analyses regarding additional cortical infarction.

CONCLUSIONS

In this exploratory study, we found no indication that infarcts in the course of the corticospinal tracts predict poor clinical outcome after successful thrombectomy in patients with embolic carotid-T or M1 occlusions. In our analysis, a significant number of patients showed a favorable 90 day outcome. Additional cortical infarcts may have a greater impact on the risk of an unfavorable outcome.

RESULTS

Good clinical outcome after 90 days (mRS 0-2) was shown in 36 out of 70 patients (51.4%), with excellent clinical outcome (mRS 0-1) in 23 patients (32.9%). Here, 58.6% patients lived at home without nursing service after 90 days. Patients with minimal additional cortical infarction in postinterventional imaging had a 75.6% better chance of excellent outcome.

Incidence, outcomes, and associated factors of isolated striatocapsular infarct after mechanical thrombectomy

OBJECTIVES

To describe baseline and procedural characteristics and clinical outcomes of isolated striatocapsular infarct (iSCI) after mechanical thrombectomy in patients with large-vessel occlusion of the anterior cerebral circulation andits clinical outcome.

METHODS

We performed a longitudinal study including all patients treated with mechanical thrombectomy at our centre between 2015 and 2017; patients were divided into 2 groups (iSCI and non-iSCI) according to whether they presented iSCI in a control CT scan at 24h.

RESULTS

Of the 83 patients identified, 22.9% developed an iSCI. There were no statically significant differences in baseline characteristics or in reperfusion times. Patients presenting iSCI showed better collateral circulation and better reperfusion rates in the bivariate analysis. No significant difference was observed for mortality at discharge or at 3 months, or for functional prognosis at 3 months.

CONCLUSIONS

Even if successful reperfusion is achieved, iSCI is a common sequela, independently of reperfusion time, especially in patients with good collateral circulation.

Early Thrombectomy Protects the Internal Capsule in Patients With Proximal Middle Cerebral Artery Occlusion

BACKGROUND AND PURPOSE

Proximal middle cerebral artery (MCA) occlusions impede blood flow to the noncollateralized lenticulostriate artery territory. Previous work has shown that this almost inevitably leads to infarction of the dependent gray matter territories in the striate even if perfusion is restored by mechanical thrombectomy. Purpose of this analysis was to evaluate potential sparing of neighboring fiber tracts, ie, the internal capsule.

METHODS

An observational single-center study of patients with proximal MCA occlusions treated with mechanical thrombectomy and receiving postinterventional high-resolution diffusion-weighted imaging was conducted. Patients were classified according to internal capsule ischemia (IC+ versus IC-) at the postero-superior level of the MCA lenticulostriate artery territory (corticospinal tract correlate). Associations of IC+ versus IC- with baseline variables as well as its clinical impact were evaluated using multivariable logistic or linear regression analyses adjusting for potential confounders.

RESULTS

Of 92 included patients with proximal MCA territory infarctions, 45 (48.9%) had an IC+ pattern. Longer time from symptom-onset to groin-puncture (adjusted odds ratio, 2.12 [95% CI, 1.19-3.76] per hour), female sex and more severe strokes were associated with IC+. Patients with IC+ had lower rates of substantial neurological improvement and functional independence (adjusted odds ratio, 0.26 [95% CI, 0.09-0.81] and adjusted odds ratio, 0.25 [95% CI, 0.07-0.86]) after adjustment for confounders. These associations remained unchanged when confining analyses to patients without ischemia in the corona radiata or the motor cortex and here, IC+ was associated with higher National Institutes of Health Stroke Scale motor item scores (β, +2.8 [95% CI, 1.5 to 4.1]) without a significant increase in nonmotor items (β, +0.8 [95% CI, -0.2 to 1.9).

CONCLUSIONS

Rapid mechanical thrombectomy with successful reperfusion of the lenticulostriate arteries often protects the internal capsule from subsequent ischemia despite early basal ganglia damage. Salvage of this eloquent white matter tract within the MCA lenticulostriate artery territory seems strongly time-dependent, which has clinical and pathophysiological implications.

Lenticulostriate arteries appearance before thrombectomy predicts good outcome in acute middle cerebral artery occlusion

Background

Endovascular therapy is widely used in acute large vessel occlusion. This study investigated whether imaging of lateral lenticulostriate arteries (LSAs) before thrombectomy would potentially be helpful for predicting prognosis of patients with acute M1 segment of middle cerebral artery occlusion (MCAO).

Methods

59 consecutive patients with acute M1 segment of MCAO treated with mechanical thrombectomy at two comprehensive stroke centers were analyzed. Patients were categorized into LSA+ (appearing of lateral LSAs) and LSA- (sparing of lateral LSAs) group according to preprocedural digital substraction angiography (DSA). Baseline data and clinical outcomes were compared. A good clinical outcome was defined as a modified Rankin Scale score of 0 to 2 at 3 months. The association between clinical and imaging parameters and functional outcome was evaluated with logistic regression analysis.

Results

LSA+ was shown in 36 patients (61%). LSA+ group had a significantly higher proportion of good outcome (72.2% vs. 8.7%, OR 27.3,95% CI 5.38–138.4, P < 0.001), lower risk of symptomatic intracranial haemorrhages (sICH) (8.3% vs. 47.8%,OR 0.10,95% CI 0.02–0.42, P = 0.001) and lower mortality in hospital (5.6% vs. 34.8%, OR 0.11,95% CI 0.02–0.58, P < 0.004) compared with LSA- group. Patients in LSA+ group had lower baseline NIHSS score(P < 0.01) and NIHSS score at 14 days(P < 0.01) and smaller infarct core volume (P = 0.016) on computed tomography perfusion imaging (CTP) compared to the LSA- group. Multivariate logistic regression analysis showed that a small infarct core volume (OR 6.74,95% CI 1.148–39.569, P = 0.035) and LSA+(OR 22.114,95% CI 3.339–146.470, P = 0.001) were associated with a good clinical outcome.

Conclusions

Our data suggest that appearance of lateral LSAs before mechanical thrombectomy would be potentially helpful for predicting favorable prognosis of patients with acute M1 segment of MCAO.

Hydroxybutyrate promotes the recovery from cerebral infarction by activating Amp-activated protein kinase signaling

Recent studies have shown that hydroxybutyrate (GHB) is effective for protection against ischemia/brain damage in rat models. However, the specific underlying mechanism is poorly understood. In line with the previous studies, the present data showed that GHB improves cerebral blood flow (CBF) and physiological variables, including pH, pCO₂ and pO₂. Using CD31-immunofluorescence staining, a reduction of blood vessel density was indicated in the middle cerebral artery occlusion (MCAO) group; however, GHB treatment enhanced the cerebral vascular density in the ischemic area. In addition, GHB treatment increased the number of BrdU/lectin double-positive cells. Furthermore, the reduction of nestin-positive cells was identified in the brain of MCAO rats, while the number of nestin-positive cells was significantly increased after GHB administration. Compared with the sham group, the activation of Amp-activated protein kinase (AMPK) was identified in MCAO rats, suggesting stress-mediated AMPK activation after ischemia. Furthermore, the western blot assay showed that GHB treatment resulted in further activation of AMPK and endothelial nitric oxide synthase (eNOS), suggesting an enhanced energy supply. In summary, the present novel data indicates that GHB promotes the recovery from cerebral infarction mainly by activating AMPK and eNOS signaling, thereby enhancing angiogenesis and neuron regeneration.

Endovascular Stroke Treatment: How Far Downstream Should We Go?

BACKGROUND

Endovascular thrombectomy has become the de facto standard in the treatment of large vessel occlusion. Previously, a correlation between good outcome and the occlusion site, measured by the 'distance to thrombus' (DT)-as the distance from the carotid T to the beginning of the thrombus-after thrombolysis could be shown. In the present study, we analyze the differences between the chances of a good outcome in respect of DT between patients treated endovascularly or intravenously.

METHODS

A dual-center database analysis including patients with stroke due to occlusion of the middle cerebral artery (MCA) was performed. Inclusion criteria were a completed treatment and full documentation of the clinical course. DT was measured in pre-treatment images. DT was correlated with the mRS at 90 days stratified according to the different treatment methods.

RESULTS

A total of 280 patients could be included. We were able to show a correlation between the chances of good clinical outcome and the occlusion site measured by DT after i.v. thrombolysis. The outcome after endovascular treatment showed no correlation with DT (p = 0.227). After a DT of 26 mm, the chances of a good outcome after i.v. thrombolysis exceeded those after endovascular treatment.

CONCLUSION

In patients with MCA occlusion, the probability for a good outcome after endovascular treatment is independent of the occlusion site in contrast to the treatment with i.v. thrombolysis. If the occlusion occurred in the periphery of the M2 region (DT > 26 mm), i.v. thrombolysis alone was superior to endovascular treatment in achieving a good outcome.

Impact of time to endovascular reperfusion on outcome differs according to the involvement of the proximal MCA territory

BACKGROUND

The time interval between symptom onset and reperfusion is a major determinant of the benefit of endovascular therapy (ET) and patients' outcome. The impact of time may be attenuated in patients with robust collaterals. However, not all regions in the middle cerebral artery (MCA) territory have access to collaterals.

PURPOSE

To evaluate if the involvement of the poorly collateralized proximal MCA territory has an impact on the degree of time dependency of patients' outcome.

METHODS

Patients with MCA occlusions treated with ET and involvement/sparing of the proximal striatocapsular MCA territory (SC+/SC-, each n=97) were matched according to their symptom onset to reperfusion times (SORTs). Correlation and impact of time on outcome was evaluated with strata of SC+/SC- using multivariate logistic regression models (LRMs), including interaction terms. Discharge National Institute of Health Stroke Scale (NIHSS-DIS) score <5 and discharge modified Rankin Scale (mRS-DIS) score ≤2 were prespecified outcome measures.

RESULTS

A stronger correlation between all outcome measures (NIHSS-DIS/ΔNIHSS/mRS-DIS) and SORTs was found for SC+ patients than for SC-patients. SORTs were significant variables in LRMs for mRS-DIS score ≤2 and NIHSS-DIS score <5 in SC+ but not in SC- patients. Interaction of SC+ and SORTs was significant in LRMs for both endpoints.

CONCLUSION

Time dependency of outcome after ET is more pronounced if parts of the proximal MCA territory are affected. This may reflect the lack of collateralization in the striatocapsular region and a more stringent cell death with time. If confirmed, this finding may affect the selection of patients based on different time windows according to the territory at risk.

Permeability Surface of Deep Middle Cerebral Artery Territory on Computed Tomographic Perfusion Predicts Hemorrhagic Transformation After Stroke

BACKGROUND AND PURPOSE

Permeability surface (PS) on computed tomographic perfusion reflects blood-brain barrier permeability and is related to hemorrhagic transformation (HT). HT of deep middle cerebral artery (MCA) territory can occur after recanalization of proximal large-vessel occlusion. We aimed to determine the relationship between HT and PS of deep MCA territory.

METHODS

We retrospectively reviewed 70 consecutive acute ischemic stroke patients presenting with occlusion of the distal internal carotid artery or M1 segment of the MCA. All patients underwent computed tomographic perfusion within 6 hours after symptom onset. Computed tomographic perfusion data were postprocessed to generate maps of different perfusion parameters. Risk factors were identified for increased deep MCA territory PS. Receiver operating characteristic curve analysis was performed to calculate the optimal PS threshold to predict HT of deep MCA territory.

RESULTS

Increased PS was associated with HT of deep MCA territory. After adjustments for age, sex, onset time to computed tomographic perfusion, and baseline National Institutes of Health Stroke Scale, poor collateral status (odds ratio, 7.8; 95% confidence interval, 1.67-37.14; P=0.009) and proximal MCA-M1 occlusion (odds ratio, 4.12; 95% confidence interval, 1.03-16.52; P=0.045) were independently associated with increased deep MCA territory PS. Relative PS most accurately predicted HT of deep MCA territory (area under curve, 0.94; optimal threshold, 2.89).

CONCLUSIONS

Increased PS can predict HT of deep MCA territory after recanalization therapy for cerebral proximal large-vessel occlusion. Proximal MCA-M1 complete occlusion and distal internal carotid artery occlusion in conjunction with poor collaterals elevate deep MCA territory PS.

Isolated Striatocapsular Infarcts after Endovascular Treatment of Acute Proximal Middle Cerebral Artery Occlusions: Prevalence, Enabling Factors, and Clinical Outcome

Background

Striatocapsular infarcts (SCIs) are defined as large subcortical infarcts involving the territory of more than one lenticulostriate artery. SCI without concomitant ischemia in the more distal middle cerebral artery (MCA) territory [isolated SCI (iSCI)] has been described as a rare infarct pattern. The purpose of this study was to assess the prevalence of iSCI in patients treated with endovascular thrombectomy (ET), to evaluate baseline and procedural parameters associated with this condition, and to describe the clinical course of iSCI patients.

Methods

A retrospective analysis of 206 consecutive patients with an isolated MCA occlusion involving the lenticulostriate arteries and treated with ET was performed. Baseline patient and procedural characteristics and ischemic involvement of the striatocapsular and distal MCA territory [iSCI, as opposed to non-isolated SCI (niSCI)] were analyzed using multivariate logistic regression models. Prevalence of iSCI was assessed, and clinical course was determined with the rates of substantial neurological improvement and good functional short- and mid-term outcome (discharge/day 90 Modified Rankin Scale ≤2).

Results

iSCI was detected in 53 patients (25.7%), and niSCI was detected in 153 patients (74.3%). Successful reperfusion [thrombolysis in cerebral infarction (TICI) 2b/3] [adjusted odds ration (aOR) 8.730, 95% confidence interval (95% CI) 1.069–71.308] and good collaterals (aOR 2.100, 95% CI 1.119–3.944) were associated with iSCI. In successfully reperfused patients, TICI 3 was found to be an additional factor associated with iSCI (aOR 5.282, 1.759–15.859). Patients with iSCI had higher rates of substantial neurological improvement (71.7 vs. 37.9%, p < 0.001) and higher rates of good functional short- and mid-term outcome (58.3 vs. 23.7%, p < 0.001 and 71.4 vs. 41.7%, p < 0.001). However, while iSCI patients, in general, had a more favorable outcome, considerable heterogeneity in outcome was observed.

Conclusion

High rates of successful reperfusion (TICI 2b/3) and in particular, complete reperfusion (TICI 3) are associated with iSCIs. The high prevalence of iSCI in successfully reperfused patients with good collaterals corroborates previous concepts of iSCI pathogenesis. iSCI, once considered a rare pattern of cerebral ischemia, is likely to become more prevalent with increases in endovascular stroke therapy. This may have implications for patient rehabilitation and pathophysiological analyses of ischemic damage confined to subcortical regions of the MCA territory.