Blood pressure levels post mechanical thrombectomy and outcomes in large vessel occlusion strokes

Abnormal Blood Flow on Transcranial Duplex Sonography Predicts Poor Outcome After Stroke Thrombectomy

Background and Purpose- Hemodynamic changes following mechanical thrombectomy for large vessel occlusion stroke could be associated with complications and might affect prognosis. We investigated postinterventional middle cerebral artery blood flow on transcranial duplex sonography (TCD) and its prognostic value for anterior large vessel occlusion stroke patients. Methods- We identified all ischemic stroke patients who had undergone mechanical thrombectomy for anterior circulation large vessel occlusion from 2010 onwards. Postinterventional middle cerebral artery flow was graded according to the sonographic Thrombolysis in Brain Ischemia score and related to patient outcome stratified by the angiographic Thrombolysis in Cerebral Infarction reperfusion status. Results- Of 215 large vessel occlusion stroke patients, 193 patients (90%) showed successful angiographic recanalization (Thrombolysis in Cerebral Infarction grade 2b-3). Of those, 69 (36%) patients had abnormal sonographic middle cerebral artery blood flow (Thrombolysis in Brain Ischemia grade 0-4) within 72 hours after mechanical thrombectomy, which was an independent predictor for poor 90-day outcome. Conclusions- TCD indicates abnormal middle cerebral artery hemodynamics in a substantial proportion of patients with angiographically defined successful mechanical thrombectomy of the anterior cerebral circulation. Such changes are associated with poor short-term outcome.

[Periinterventional management of acute endovascular stroke treatment]

Mechanical thrombectomy (MT) is more effective than standard medical treatment with or without intravenous thrombolysis alone for treating acute ischemic stroke (AIS) caused by large vessel occlusion (LVO) in the anterior circulation. MT is therefore recommended in current international guidelines, and many acute-care hospitals and stroke centers will have to prepare for providing this treatment in an optimal way. Beside successful recanalization, management before, during, and after the intervention represents significant challenges. One unresolved matter is whether the choice of anesthetic strategy, including airway management, affects functional outcome. Based on current data, treatment under general anesthesia (GA)-respecting predefined safety criteria and contraindications-seem seems to be equivalent to treating the patient in conscious sedation (CS) and not necessarily disadvantageous. Aspects of periinterventional management of MT, including pragmatic recommendations concerning logistics, monitoring, postprocedural steps, and follow-up imaging, will be summarized in this overview.

Association of Blood Pressure During Thrombectomy for Acute Ischemic Stroke With Functional Outcome: A Systematic Review

Background and Purpose- Optimal blood pressure (BP) targets during mechanical thrombectomy (MT) for acute ischemic stroke (AIS) are unknown, and randomized controlled trials addressing this issue are lacking. We aimed to perform a systematic review of studies evaluating the influence of periprocedural BP on functional outcome after MT. Methods- Studies assessing periprocedural BP effect on functional outcome published after January 1st, 2012 were included in the systematic review. The PRISMA checklist and flow diagram were followed for the design and reporting of this work. Results- Nine studies were included, for a total of 1037 patients. The heterogeneity in findings with respect to BP monitoring and studied parameters precluded a meta-analysis. Mean arterial pressure was the most frequently reported parameter to describe BP variability during MT, and systolic BP was the main parameter used to define periprocedural BP targets. Five studies suggested an association between 3 types of BP drops as predictors of poor functional outcome at 3 months: >40% drop in mean arterial pressure compared with baseline (odds ratio=2.8; [1.09-7.19]; P=0.032), lowest mean arterial pressure before recanalization (odds ratio=1.28; [1.01-1.62] per 10 mm Hg drop below 100 mm Hg; P=0.04), and MAP drops (odds ratio=4.38; [1.53-12.6] for drops >10%). Four studies did not show an association between BP during MT and functional outcome, including 3 studies with strict periprocedural systolic BP targets (within a 140-180 mm Hg). Conclusions- BP drops during MT may be associated with a worse functional outcome. When strict systolic BP targets are achieved, no association between BP and functional outcome was also noted. Both conclusions require further evaluation in randomized studies.

Is intravenous thrombolysis still necessary in patients who undergo mechanical thrombectomy?

PURPOSE OF REVIEW

To summarize available evidence on the potential utility of pretreatment with intravenous thrombolysis (IVT) using recombinant tissue-plasminogen activator (rt-PA) in acute ischemic stroke (AIS) patients with large vessel occlusions (LVO) who are treated with mechanical thrombectomy.

RECENT FINDINGS

Despite theoretical concerns of a higher bleeding risk with IVT pretreatment, there are no data showing increased risk of symptomatic intracerebral hemorrhage (sICH) in patients with LVO receiving bridging therapy (IVT and mechanical thrombectomy) compared with direct mechanical thrombectomy (dMT). Additionally, evidence from observational studies suggest lower rates of infarctions in previously unaffected territories and higher rates of successful reperfusion, with lower number of device passes, in patients receiving bridging therapy. There are substantial discrepancies in studies comparing clinical outcomes between dMT and bridging therapy that are directly related to the inclusion of patients with contraindications to IVT in the dMT group. Ongoing clinical trials will provide definitive answers on the potential additional benefit of IVT in LVO patients receiving mechanical thrombectomy.

SUMMARY

IVT and mechanical thrombectomy are two effective reperfusion therapies that should be used in a swift and noncompeting fashion in AIS patients. AIS patients with LVO and no contraindications for IVT should receive promptly rt-PA bolus followed by immediate initiation of mechanical thrombectomy as indicated by current international recommendations, unless future randomized controlled trials provide evidence to proceed differently.

Acute ischaemic stroke: challenges for the intensivist

PURPOSE

To provide an update about the rapidly developing changes in the critical care management of acute ischaemic stroke patients.

METHODS

A narrative review was conducted in five general areas of acute ischaemic stroke management: reperfusion strategies, anesthesia for endovascular thrombectomy, intensive care unit management, intracranial complications, and ethical considerations.

RESULTS

The introduction of effective reperfusion strategies, including IV thrombolysis and endovascular thrombectomy, has revolutionized the management of acute ischaemic stroke and transformed outcomes for patients. Acute therapeutic efforts are targeted to restoring blood flow to the ischaemic penumbra before irreversible tissue injury has occurred. To optimize patient outcomes, secondary insults, such as hypotension, hyperthermia, or hyperglycaemia, that can extend the penumbral area must also be prevented or corrected. The ICU management of acute ischaemic stroke patients, therefore, focuses on the optimization of systemic physiological homeostasis, management of intracranial complications, and neurological and haemodynamic monitoring after reperfusion therapies. Meticulous blood pressure management is of central importance in improving outcomes, particularly in patients that have undergone reperfusion therapies.

CONCLUSIONS

While consensus guidelines are available to guide clinical decision making after acute ischaemic stroke, there is limited high-quality evidence for many of the recommended interventions. However, a bundle of medical, endovascular, and surgical strategies, when applied in a timely and consistent manner, can improve long-term stroke outcomes.

Blood Pressure and Outcome After Mechanical Thrombectomy With Successful Revascularization

Background and Purpose- Successful reperfusion can be achieved in more than two-thirds of patients treated with mechanical thrombectomy. Therefore, it is important to understand the effect of blood pressure (BP) on clinical outcomes after successful reperfusion. In this study, we investigated the relationship between BP on admission and during the first 24 hours after successful reperfusion with clinical outcomes. Methods- This was a multicenter study from 10 comprehensive stroke centers. To ensure homogeneity of the studied cohort, we included only patients with anterior circulation who achieved successful recanalization at the end of procedure. Clinical outcomes included 90-day modified Rankin Scale, symptomatic intracerebral hemorrhage (sICH), mortality, and hemicraniectomy. Results- A total of 1245 patients were included in the study. Mean age was 69±14 years, and 51% of patients were female. Forty-nine percent of patients had good functional outcome at 90-days, and 4.7% suffered sICH. Admission systolic BP (SBP), mean SBP, maximum SBP, SBP SD, and SBP range were associated with higher risk of sICH. In addition, patients in the higher mean SBP groups had higher rates of sICH. Similar results were found for hemicraniectomy. With respect to functional outcome, mean SBP, maximum SBP, and SBP range were inversely associated with the good outcome (modified Rankin Scale score, 0-2). However, the difference in SBP parameters between the poor and good outcome groups was modest. Conclusions- Higher BP within the first 24 hours after successful mechanical thrombectomy was associated with a higher likelihood of sICH, mortality, and requiring hemicraniectomy.

Association of maximal systolic blood pressure with poor outcome in patients with hyperattenuated lesions on immediate NCCT after mechanical thrombectomy

Background and purpose

This study aimed to investigate the relationship between blood pressure (BP) management and clinical outcome in patients with hyperattenuated lesions on non-contrast CT (NCCT) immediately after mechanical thrombectomy (MT).

Methods

We retrospectively reviewed our prospectively collected cohort for consecutive patients with acute ischemic stroke (AIS) who received MT between October 2013 and July 2018. Hourly systolic BP (SBP) and diastolic BP (DBP) values were recorded for 24 hours following MT, and then maximum SBP (SBPmax) and DBP (DBPmax) values were identified. Poor outcome was defined as 3-month modified Rankin score (mRS) 3–6 and parenchymal hemorrhage (PH) was defined according to the European Cooperative Acute Stroke Study (ECASS) II trial. Associations of BP parameters with poor outcome and PH were determined using binary logistic regression models. Receiver operating characteristics (ROC) curve analysis was used to determine the predictive value of BP.

Results

Initially 262 patients with AIS who received MT were reviewed and 148 patients with hyperattenuated lesions on immediate NCCT were enrolled in the final cohort for analysis. Binary logistic regression showed that every 10 mm Hg increase in SBPmax was independently associated with a poor outcome (OR 1.426; 95% CI 1.095 to 1.855; p=0.008) and PH (OR 1.025; 95% CI 1.005 to 1.480; p=0.044). SBP ≤140 mm Hg during the post-procedural 24-hour period was associated with lower odds of a poor outcome and PH compared with the other group.

Conclusions

Control of maximal SBP within 24 hours might be related to a low rate of PH and poor outcome in patients with hyperattenuated lesions on immediate NCCT after intervention.

Associations of various blood pressure parameters with functional outcomes after endovascular thrombectomy in acute ischaemic stroke

BACKGROUND AND PURPOSE

High blood pressure (BP) at presentation is associated with poor outcomes in acute ischaemic stroke, but serial BP measurements may better delineate the clinical implications of BP. The aim was to investigate the association between various BP parameters and functional outcomes in acute ischaemic stroke patients treated with endovascular thrombectomy (EVT).

METHODS

This study reports a retrospective analysis of a prospective registry of a comprehensive stroke centre. Patients treated with EVT due to large vessel occlusion in the anterior circulation were enrolled. BP was measured hourly during the first 24 h after admission. Associations of various BP parameters, including BP variability, with functional outcomes at 3 months, including good outcomes (modified Rankin Scale score of 0-2), were analysed.

RESULTS

Of the 378 enrolled patients (mean age 70 ± 11 years, male 54.2%), 313 (82.8%) achieved successful reperfusion after EVT, and 149 (39.4%) had good outcomes at 3 months. Higher mean systolic BP [each 10 mmHg increase, odds ratio 0.82 (0.69-0.97)] and higher systolic successive variation (SV) [each 10% increase, odds ratio 0.37 (0.18-0.76)] were associated with a reduced likelihood of achieving good outcomes. In addition, reperfusion status after EVT moderated the influence of higher systolic SV on good outcomes (P_int  = 0.05).

CONCLUSION

The results showed that a higher mean systolic BP and systolic SV during the first 24 h of EVT reduced the likelihood of good outcomes at 3 months. The effects of these parameters on outcomes are more substantial amongst patients with successful reperfusion after EVT, suggesting that different BP control strategies should be employed according to reperfusion status.

Optimal blood pressure after reperfusion therapy in patients with acute ischemic stroke

We investigated the relationship between the mean blood pressure (BP) at 24-72 h and the clinical outcomes after acute ischemic stroke (AIS) in patients treated with reperfusion therapy. The primary outcome was measured using the modified Rankin Scale (mRS) at 3 months after AIS, and was based on the mean systolic BP at 24-72 h post-AIS. Favorable outcome was defined as mRS scores of 0-2. A total of 1,540 patients treated with reperfusion therapy were enrolled in the study. Favorable outcomes occurred more frequently in patients with BP ≤ 130/80 mmHg, and the risks of symptomatic intracranial hemorrhage and early neurological deterioration were lower in this optimal BP group. Multivariable analysis showed a significant association between mean BP ≤ 130/80 mmHg at 24-72 h and favorable outcomes at 3 months after AIS (odds ratio 2.95, 95% confidence interval 2.32-3.77, p < 0.001). Prespecified subgroup analyses showed that BP ≤ 130/80 mmHg had a more significant impact on clinical outcome in patients with recanalization than in those without recanalization. These data indicate that a mean BP of ≤ 130/80 mmHg at 24-72 h post-AIS is independently associated with favorable outcomes in patients treated with reperfusion therapy, particularly in those with recanalization.

Comorbidities Related to Clinical Outcomes in Patients With Acute Ischemic Stroke Undergoing Mechanical Thrombectomy: Review of Literature and Experience at a Single Comprehensive Stroke Center

Background: Recent clinical trials have shown mechanical thrombectomy (MT) to have clinical benefit for patients with acute ischemic stroke. The purpose of this study was to identify comorbid conditions that correlate with functional nonindependence in patients with acute ischemic stroke who underwent MT at a single comprehensive stroke center. Methods: Patients who had multiphase computed tomography angiography (MCTA) and subsequently underwent MT were included in this study. The modified Rankin Scale (mRS) scores at baseline (prestroke) and at 90 days were established by reviewing patients' histories and medical record documentation. Comorbid conditions were obtained from electronic medical records. Multivariate analysis was performed for body mass index, chronic hypertension, diabetes, hemoglobin A1c, peripheral artery disease, and hyperlipidemia to determine the impact of comorbidities on functional outcome. Age was analyzed using linear regression. Functional independence was defined as an mRS score of 0-2, and functional nonindependence was defined as an mRS score >2. Results: During the study period, 721 patients underwent MCTA, and 134 patients were included for MT. Patients with chronic hypertension and peripheral artery disease showed a statistically significant association with functional nonindependence at 90 days (P=0.005 and P=0.0125, respectively). Younger age at presentation was correlated with functional nonindependence using linear regression (P=0.0001). Conclusion: Hypertension, peripheral artery disease, and younger age at presentation are correlated with poor functional outcome in patients with acute ischemic stroke undergoing MT.

Acute Blood Pressure Management in Neurocritically Ill Patients

Optimal blood pressure (BP) management is controversial in neurocritically ill patients due to conflicting concerns of worsening ischemia with decreased BP versus cerebral edema and increased intracranial pressure with elevated BP. In addition, high-quality evidence is lacking regarding optimal BP goals in patients with most of these conditions. This review summarizes guideline recommendations and examines the literature for BP management in patients with ischemic stroke, intracerebral hemorrhage, aneurysmal subarachnoid hemorrhage, traumatic brain injury, and spinal cord injury.

Blood pressure variability and hemorrhagic transformation in patients with successful recanalization after endovascular recanalization therapy: A retrospective observational study

OBJECTIVE

Although blood pressure (BP) variability has been regarded as a risk factor for hemorrhagic transformation (HTF) after intravenous thrombolysis, its effect on HTF after endovascular recanalization therapy (ERT) remains to be elucidated. We aimed to study the relationship between BP variability and symptomatic intracerebral hemorrhage (sICH) after successful recanalization with ERT.

METHODS

A total of 211 patients with acute ischemic stroke and successful recanalization (thrombolysis in cerebral infarction 2b or 3) after ERT were included between January 2013 and May 2017. The BP data following ERT was obtained over the first 24 hours using parameters including mean, maximum, minimum, difference between maximum and minimum, standard deviation, coefficient of variation, successive variations, and time rate (TR) of BP variation for systolic BP (SBP) and diastolic BP. sICH was defined as parenchymal hemorrhage type 2 with neurological deterioration of 4 points of more on the National Institute of Health Stroke Scale.

RESULTS

Among the included patients, 20 (9.5%) developed sICH after successful ERT. The parameters linked with BP fluctuation over time were significantly related to sICH. After adjusting for confounders, the TR of SBP (per 0.1 mmHg/min increase) variation was independently associated with sICH (odds ratio = 1.71, 95% confidence interval = 1.013-2.886).

INTERPRETATION

Time-related BP variability in the first 24 hours following successful ERT was more correlated with sICH than other absolute BP levels. This suggests that maintaining a stable BP may be an important factor in preventing sICH after successful ERT. Ann Neurol 2019;85:574-581.

Management of Blood Pressure During and After Recanalization Therapy for Acute Ischemic Stroke

Ischemic stroke is a common neurologic condition and can lead to significant long term disability and death. Observational studies have demonstrated worse outcomes in patients presenting with the extremes of blood pressure as well as with hemodynamic variability. Despite these associations, optimal hemodynamic management in the immediate period of ischemic stroke remains an unresolved issue, particularly in the modern era of revascularization therapies. While guidelines exist for BP thresholds during and after thrombolytic therapy, there is substantially less data to guide management during mechanical thrombectomy. Ideal blood pressure targets after attempted recanalization depend both on the degree of reperfusion achieved as well as the extent of infarction present. Following complete reperfusion, lower blood pressure targets may be warranted to prevent reperfusion injury and promote penumbra recovery however prospective clinical trials addressing this issue are warranted.

Ultrasound Identification of Patients at Increased Risk of Intracranial Hemorrhage After Successful Endovascular Recanalization for Acute Ischemic Stroke

BACKGROUND

Intracranial hemorrhage (ICH) is the most feared complication of endovascular treatment (EVT) for acute ischemic stroke because of anterior circulation large vessel occlusion (LVO). The purpose of this study was to identify cerebral hemodynamic predictors of ICH and poor outcome in patients with successful recanalization.

METHODS

Serial transcranial color-coded sonography (TCCS) examinations assessed vessel status and cerebral hemodynamics of 226 (mean age, 69.8 ± 12.5 years; 130 men [57.5%]) consecutive patients with acute anterior circulation LVO at 48 hours and 1 week after EVT. Middle cerebral artery peak systolic velocity (PSV_MCA) and PSV_MCA ratio (recanalized PSV_MCA/contralateral PSV_MCA) were recorded.

RESULTS

Out of 180 successfully recanalized patients (79.6%), 28 patients (15.5%) had ICH. They more often had arterial hypertension (25/28 [89.3%] vs. 106/152 [69.7%], P = 0.04), a more severe stroke syndrome (18 [range, 10-23] vs. 16 [range, 5-26], P = 0.01), a worse clinical outcome (90-day modified Rankin Scale [mRS] score 3-5: 16/28 [57.1%] vs. 42/152 [27.6%], P = 0.004), and soon after EVT showed a significantly higher mean PSV_MCA ratio (3.4 ± 0.1 vs. 2.4 ± 0.1, P < 0.0001) than patients without ICH, respectively. In multivariate analysis, early PSV_MCA ratio was independently associated with postinterventional ICH (odds ratio, 13.379; 95% confidence interval, 2.466-50.372; P < 0.01). The patients with ICH (19/28 [67.9%]) who resumed normal PSV_MCA values at 1 week after EVT had a better outcome (90-day mRS score 0-2: 8/19 [42.1%] vs. 0/9 [0%], respectively).

CONCLUSIONS

Early TCCS detection of a high PSV_MCA ratio in successfully recanalized stroke patients indicates an increased risk of ICH, whereas cerebral hemodynamics normalization at 1 week in patients with postinterventional ICH predicts a relatively better 3-month outcome.

Impact of blood pressure levels within first 24 hours after mechanical thrombectomy on clinical outcome in acute ischemic stroke patients

INTRODUCTION

Despite early management and technical success of mechanical thrombectomy (MT) for acute ischemic stroke (AIS), not all patients reach a good clinical outcome. Different factors may have an impact and we aimed to evaluate blood pressure (BP) levels in the first 24 hours after MT.

METHODS

Consecutive AIS patients treated with MT were enrolled in the retrospective bi-center study. Neurological deficit was assessed with National Institutes of Health Stroke Scale (NIHSS) and functional outcome after 3 months with modified Rankin scale (mRS) with a score 0-2 for good outcome. The presence of symptomatic intracerebral hemorrhage (SICH) was assessed according to the SITS-MOST criteria.

RESULTS

Of 703 treated patients, completed BP levels were collected in 690 patients (350 males, mean age 71±13 years) with median of admission NIHSS 17 points. Patients with mRS 0-2 had a lower median of systolic BP (SBP) compared with those with poor outcome (131 vs 140 mm Hg, P<0.0001). The rate of SICH did not differ between the patients with a median of SBP <140 mm Hg and ≥140 mm Hg. (5.1% vs 5.1%, P=0.980). Multivariate regression analysis with adjustment for potential confounders showed a median of distolic BP (P=0.024, OR: 0.977, 95% CI: 0.957 to 0.997) as a predictor of good functional outcome after MT, and a median of maximal SBP (P=0.038; OR: 0.990, 95% CI: 0.981 to 0.999) in the patients with achieved recanalization.

CONCLUSION

Lowering of BP within the first 24 hours after MT may have a positive impact on clinical outcome in treated patients.

Mechanical thrombectomy outcomes in large vessel stroke with high international normalized ratio

OBJECTIVE

Evaluating the safety and efficacy of mechanical thrombectomy (MT) in acute stroke patients due to emergent large vessel occlusion (ELVO) with high international-normalized-ratio (INR).

METHODS

Consecutive ELVO patients treated with MT were evaluated from two centers. Outcome measures included symptomatic-intracranial-hemorrhage(sICH), three-month mortality, successful reperfusion(SR), and 3-month functional-independence(FI; mRS-scores of 0-2). Additionally, a meta-analysis of available cohort studies was performed to evaluate safety and efficacy of MT in ELVO patients with high INR.

RESULTS

A total of 315 ELVO patients were evaluated. Of those 10 patients had INR >1.7 [mean age 63.5 ± 15, median NIHSS-score: 17 points (IQR 14-22)],and remaining 305 ELVO patients had INR ≤ 1.7 ([mean age 62 ± 14.4, median NIHSS-score: 17 points (IQR 12-21)]. Patients with high INR did not differ in terms of sICH (10.0% vs. 6.9%; p = .706), 3-month mortality (20.0% vs. 24.2%; p = .762), SR (88.9% vs. 69.4%; p = .209) and 3-month FI (50% vs. 49.3%; p = .762) compared to the rest. Meta-analysis of available studies (n = 5) showed that high INR was not related to sICH (OR: 0.94, 95%CI: 0.42-2.07; p = .88), 3-month mortality (OR: 1.07, 95%CI: CI 0.72-1.60; p = .73) and 3-month FI (OR: 0.69, 95%CI: 0.34-1.40; p = .30).

CONCLUSIONS

MT can be performed safely and effectively in ELVO patients with high INR.

Higher Blood Pressure during Endovascular Thrombectomy in Anterior Circulation Stroke Is Associated with Better Outcomes

Background and Purpose

Reports investigating the relationship between in-procedure blood pressure (BP) and outcomes in patients undergoing endovascular thrombectomy (EVT) due to anterior circulation stroke are sparse and contradictory.

Methods

Consecutive EVT-treated adults (modern stent retrievers, BP managed in line with the recommendations, general anesthesia, invasive BP measurements) were evaluated for associations of the rate of in-procedure systolic BP (SBP) and mean arterial pressure (MAP) excursions to >120%/<80% of the reference values (serial measurements at anesthesia induction) and of the reference BP/weighted in-procedure mean BP with post-procedure imaging outcomes (ischemic lesion volume [ILV], hemorrhages) and 3-month functional outcome (modified Rankin Scale [mRS], score 0 to 2 vs. 3 to 6).

Results

Overall 164 patients (70.7% pharmacological reperfusion, 80.5% with good collaterals, 73.8% with successful reperfusion) were evaluated for ILV (range, 0 to 581 cm³) and hemorrhages (incidence 17.7%). Higher rate of in-procedure SBP/MAP excursions to >120% was independently associated with lower ILV, while higher in-procedure mean SBP/MAP was associated with lower odds of hemorrhages. mRS 0-2 was achieved in 75/155 (48.4%) evaluated patients (nine had missing mRS data). Higher rate of SBP/MAP excursions to >120% and higher reference SBP/MAP were independently associated with higher odds of mRS 0-2, while higher ILV was associated with lower odds of mRS 0-2. Rate of SBP/MAP excursions to <80% was not associated with any outcome.

Conclusions

In the EVT-treated patients with BP managed within the recommended limits, a better functional outcome might be achieved by targeting in-procedure BP that exceeds the preprocedure values by more than 20%.

Factors that may contribute to poor outcome despite good reperfusion after acute endovascular stroke therapy

Endovascular therapy with mechanical thrombectomy is a formidable treatment for severe acute ischemic stroke caused by occlusion of a proximal intracranial artery. Its strong beneficial effect is explained by the high rates of very good and excellent reperfusion achieved with current endovascular techniques. However, there is a sizable proportion of patients who do not experience clinical improvement despite successful recanalization of the occluded artery and reperfusion of the ischemic territory. Factors such as baseline reserve, collateral flow, anesthesia and systemic factors have been identified as potential culprits for lack of improvement in the setting of timely and successful revascularization. Older age, baseline disability and perhaps radiological markers of chronic brain injury can affect the prognosis of patients treated with endovascular therapy. Collateral flow is a major determinant of outcome after endovascular therapy and it is manifested by the size of the core in relation to the volume of the salvageable tissue. Parenchymal and vascular imaging can help assess the quality of collateral flow, but the optimal radiological strategy for daily practice (i.e. the optimal combination of rapid availability and diagnostic precision) has not been established. A sizable body of observational evidence indicates that acute hypertension, hyperglycemia and fever are associated with worse outcomes after a stroke even after optimal reperfusion with endovascular therapy. Lastly, current randomized controlled trials in anesthesia for stroke demonstrate similar rates of good functional outcome between general anesthesia and conscious sedation suggesting equipoise exists.

Microcatheter navigation through the clot: does size matter?

BACKGROUND

Despite high recanalization rates achieved with endovascular treatment of acute ischemic strokes, around 50% of eligible patients will not achieve a good outcome. Parameters that may determine patient outcomes include: time from puncture to recanalization, the collateral status, the anesthesia regimen, blood pressure management, and distal emboli. Characterization of distal emboli generated during mechanical thrombectomy has been performed in previous studies.

OBJECTIVE

To further investigate the risk of distal embolization associated with microcatheter navigation across the clot.

METHODS

A contrast-enhanced clot analog was used in an in vitro model that mimicked a middle cerebral artery occlusion within a complete circle of Willis vascular replica. The clot was crossed with one of the following microcatheters: Pro18, XT-27 or 3MAX. The emboli generated during the procedure were collected and measured.

RESULTS

The use of Pro18 and XT-27 resulted in a significant reduction of visible particles (size ≥500 µm) as compared with the 3MAX catheter (P<0.003). For the size range between 8 and 200 µm, there was a trend for Pro18 to generate fewer particles (-18%) than XT-27 but without statistical significance (P>0.05). In comparison with previously published data, acquired under the same conditions, it was found that the clot crossing maneuver accounts approximately for 12% of the total number of small emboli (<200 µm) induced during a stent retriever-mediated mechanical thrombectomy procedure via a balloon guide catheter.

CONCLUSIONS

The clot crossing maneuver has a significant effect on the total number of small particles induced during mechanical thrombectomy. Smaller microcatheter sizes should be favored when possible.

[To optimize the initial assessment for stroke patients transferred from general hospital may improve the clinical outcome after endovascular thrombectomy]

Rapid adaption of endovascular thrombectomy (EVT) is essential for patients with large arterial occlusion (LAO). Although patients transferred need longer transportation, they have an advantage of preadmission diagnosis regarding arterial occlusion. The aim of the present study is to evaluate whether optimizing the assessment at comprehensive center for patients transferred may improve the clinical outcome after EVT. Data on consecutive patients treated with EVT between September 2014 and May 2017 were studied. Generally, we have two distinct protocols for EVT candidates: 1) the transfer group, patients are directly taken to the CT and escorted to the angiography room; and 2) the direct group, patients receive the routine emergent evaluation and examined with MRI/MRA. Good outcome was defined as modified Rankin Scale score ≤1 at 3 months. Thirty-one (29%) patients were classified into the transfer group and the 77 (71%) were into the direct group. Although the onset to door time was longer in the transfer group (175 [137-275] min. vs. 76 [51-260] min, P = 0.001), the rate of good outcome was similar between the 2 groups (41% vs. 25%, P = 0.205). By multivariate regression analysis, the onset to reperfusion time was the independent factor (odds ratio 0.982, 95%CI: 0.967-0.998, P = 0.026) associated with good outcome, while transfer itself was not the independent parameter (odds ratio 0.732, 95%CI: 0.125-4.291, P = 0.730). Regarding time parameters, door to picture time (11 [7-24] min vs. 27 [21-39] min., P < 0.001) and picture to puncture time (27 [18-60] min. vs. 54 [39-78] min, P < 0.001) were shorter in the transfer group. Thus, the onset to puncture time (234 [177-299] min. vs. 170 [125-367] min, P = 0.063) and the onset to reperfusion time (271 [208-352] min. vs. 237 [159-382] min., P = 0.183) were similar between the 2 groups. Shortening the initial evaluation at comprehensive stroke center can provide a good outcome for patients transferred.

Active Reperfusion Hemorrhage during Thrombectomy: Angiographic Findings and Real-Time Correlation with the CT "Spot Sign"

Introduction

Symptomatic intracranial hemorrhage represents one of the most feared complications of endovascular reperfusion. We aim to describe a series of patients that experienced immediate reperfusion injury with active intraprocedural extravasation within the territory of the deep penetrating arteries and provide real-time correlation with CT "spot sign."

Methods

This was a retrospective analysis of patients that suffered reperfusion injury with active arterial extravasation during endovascular stroke treatment in two tertiary care centers.

Results

Five patients were identified. Median age was 63 (58-71) years, 66% were male. Median NIHSS was 13.5 (9.5-23.0), platelet level 212,000 (142,000-235,000), baseline systolic blood pressure 152 (133-201) mm Hg, and non-contrast CT ASPECTS 7.0 (6.5-9.0). Two patients were taking aspirin and one had received intravenous thrombolysis. There were three middle cerebral artery M1, one internal carotid artery terminus, and one vertebrobasilar junction occlusion. Three patients had anterior circulation tandem occlusions. Stroke etiology was extracranial atherosclerosis (n = 2), intracranial atherosclerosis (n = 2), and cervical dissection (n = 1). The median time from onset to puncture was 5.5 (3.9-8.6) h. Intravenous heparin was administered in all patients (median dose of 4,750 [3,250-6,000] units) and intravenous abciximab in four. All tandem cases had the cervical lesion addressed first. Four lenticulostriates and one paramedian pontine artery were involved. Intraprocedural flat-panel CT was performed in four (80%) cases and provided real-time correlation between the active contrast extravasation and the "spot sign." The bailout included use of protamine, blood pressure control, and balloon guide catheter or intracranial compliant balloon inflation plus coiling of targeted vessel. All patients had angiographic cessation of bleeding at the end of the procedure with parenchymal hemorrhage type 1 in one case and type 2 in four. Three patients had modified Rankin score of 4 and two were dead at 90 days.

Conclusions

Active reperfusion hemorrhage involving perforator arteries was observed to correlate with the CT "spot sign" and to be associated with poor outcomes.

Blood Pressure Management after Mechanical Thrombectomy for Acute Ischemic Stroke: A Survey of the StrokeNet Sites

BACKGROUND

It is unclear what factors providers take into account to determine the target blood pressure (BP) after mechanical thrombectomy (MT) in patients who had acute ischemic stroke. We aimed to understand practice patterns of post-MT BP management across institutions in the United States.

METHODS

We surveyed StrokeNet institutions providing MT and post-MT care with an online questionnaire, designed to understand institutional post-MT BP management practices.

RESULTS

Of 131 potential institutions, 58 completed the survey. The majority of institutions target systolic BP (SBP, n = 53, 91%) during the first 24 hours post-MT (n = 32, 55%) using nicardipine as a first-line agent (n = 43, 74%). At most institutions, BP management is determined by a team of physicians in a collaborative fashion (n = 30, 52%) and individualized on a case-by-case basis (n = 39, 67%) after taking the reperfusion status into account (n = 42, 72%). In patients with successful reperfusion, 36% (n = 21) of the institutions target SBP in the range of 120-139 mm Hg, 21% (n = 12) target 140-159 mm Hg, and 28% (n = 16) would accept any value less than or equal to 180 mm Hg. In patients with unsuccessful reperfusion, 43% (n = 25) would accept any SBP value less than or equal to 180 mm Hg and 10% (n = 6) would target SBP less than or equal to 220 mm Hg.

CONCLUSIONS

We found that majority of the institutions do not have a standardized protocol for post-MT BP management. There was interinstitutional heterogeneity in the preferred target of SBP post-MT and most institutions target values of SBP lower than 180 mm Hg in post-MT patients. Prospective data and randomized control trial are needed to identify the optimal target BP.

Endovascular Treatment of Anterior Circulation Large Vessel Occlusion in the Elderly

Endovascular treatment of anterior circulation large vessel occlusion in the elderly population presents special challenges and opportunities. In this review, we discuss the published literature regarding thrombectomy in elderly patients and also discuss specific issues related to treatment in this patient population. In summary, while the overall outcomes following thrombectomy in elderly patients are worse than following thrombectomy in younger patients, there appears to be a similar benefit as in young patients. While there are challenges with successfully delivering thrombectomy in older patients, age alone should not be an independent exclusion from thrombectomy.

Blood pressure levels post mechanical thrombectomy and outcomes in non-recanalized large vessel occlusion patients

Objective

Permissive hypertension may benefit patients with non-recanalized large vessel occlusion (nrLVO) post mechanical thrombectomy (MT) by maintaining brain perfusion. Data evaluating the impact of post-MT blood pressure (BP) levels on outcomes in nrLVO patients are scarce. We investigated the association of the post-MT BP course with safety and efficacy outcomes in nrLVO.

Methods

Hourly systolic BP (SBP) and diastolic BP (DBP) values were prospectively recorded for 24 hours following MT in consecutive nrLVO patients. Maximum, minimum, and mean BP levels were documented. Three-month functional independence (FI) was defined as modified Rankin Scale (mRS) scores of 0–2.

Results

A total of 88 nrLVO patients were evaluated post MT. Patients with FI had lower maximum SBP (160±19 mmHg vs 179±23 mmHg; P=0.001) and higher minimum SBP levels (119±12 mmHg vs 108±25 mmHg; P=0.008). Maximum SBP (183±20 mmHg vs 169±23 mmHg; P=0.008) and DBP levels (105±20 mmHg vs 89±18 mmHg; P=0.001) were higher in patients who died at 3 months while minimum SBP values were lower (102±28 mmHg vs 115±16 mmHg; P=0.007). On multivariable analyses, both maximum SBP (OR per 10 mmHg increase: 0.55, 95% CI 0.39 to 0.79; P=0.001) and minimum SBP (OR per 10 mmHg increase: 1.64, 95% CI 1.04 to 2.60; P=0.033) levels were independently associated with the odds of FI. Maximum DBP (OR per 10 mmHg increase: 1.61; 95% CI 1.10 to 2.36; P=0.014) and minimum SBP (OR per 10 mmHg increase: 0.65, 95% CI 0.47 to 0.90; P=0.009) values were independent predictors of 3-month mortality.

Conclusions

Our study demonstrates that wide BP excursions from the mean during the first 24 hours post MT are associated with worse outcomes in patients with nrLVO.

Increased middle cerebral artery mean blood flow velocity index after stroke thrombectomy indicates increased risk for intracranial hemorrhage

Background and purpose

Cerebral hyperperfusion has been related to the risk of intracranial hemorrhage (ICH) in stroke patients after vessel recanalization therapy. We hypothesized that after successful mechanical thrombectomy for acute anterior circulation stroke, hemodynamics detectable by transcranial Duplex (TCD) sonography would vary, and that increased blood flow velocities would be associated with ICH.

Methods

We retrospectively identified all ischemic stroke patients with successful endovascular recanalization for anterior circulation vessel occlusion (Thrombolysis in Cerebral Infarction 2b–3) between 2010 and 2017. We reviewed their postinterventional TCD examinations for mean blood flow (MBF) velocities of the recanalized and contralateral middle cerebral artery (MCA) and searched for an association with postinterventional ICH and clinical outcome.

Results

123 stroke patients (mean age 63±14 years, 40% women) with successful anterior circulation thrombectomy were analyzed. Of those, 18 patients had postinterventional ICH. ICH patients had an increased MCA MBF velocity index (=MBF velocity of the recanalized divided by the contralateral MCA) compared with non-ICH patients (1.32±0.39 vs 1.02±0.32, P<0.001). In multivariate analysis, a higher MCA MBF velocity index was associated with postinterventional ICH and poor 90 day outcome.

Conclusions

A high MCA MBF velocity index on TCD after successful recanalization therapy for anterior circulation stroke indicates a risk for postinterventional ICH and worse prognosis.

Antiplatelet pretreatment and outcomes following mechanical thrombectomy for emergent large vessel occlusion strokes

BACKGROUND

Few data are available regarding the safety and efficacy of antiplatelet (APT) pretreatment in acute ischemic stroke (AIS) patients with emergent large vessel occlusions (ELVO) treated with mechanical thrombectomy (MT). We sought to evaluate the association of APT pretreatment with safety and efficacy outcomes following MT for ELVO.

METHODS

Consecutive ELVO patients treated with MT during a 4-year period in a tertiary stroke center were evaluated. The following outcomes were documented using standard definitions: symptomatic intracranial hemorrhage (sICH), successful recanalization (SR; modified TICI score 2b/3), mortality, and functional independence (modified Rankin Scale scores of 0-2).

RESULTS

The study population included 217 patients with ELVO (mean age 62±14 years, 50% men, median NIH Stroke Scale score 16). APT pretreatment was documented in 71 cases (33%). Patients with APT pretreatment had higher SR rates (77% vs 61%; P=0.013). The two groups did not differ in terms of sICH (6% vs 7%), 3-month mortality (25% vs 26%), and 3-month functional independence (50% vs 48%). Pretreatment with APT was independently associated with increased likelihood of SR (OR 2.18, 95% CI1.01 to 4.73; P=0.048) on multivariable logistic regression models adjusting for potential confounders. A significant interaction (P=0.014) of intravenous thrombolysis (IVT) pretreatment on the association of pre-hospital antiplatelet use with SR was detected. APT pretreatment was associated with SR (OR 2.74, 95% CI 1.15 to 6.54; P=0.024) in patients treated with combination therapy (IVT and MT) but not in those treated with direct MT (OR 1.78, 95% CI 0.63 to 5.03; P=0.276).

CONCLUSION

APT pretreatment does not increase the risk of sICH and may independently improve the odds of SR in patients with ELVO treated with MT. The former association appears to be modified by IVT.

Vascular medicine and thrombectomy in stroke

The treatment of stroke caused by intracranial vessel occlusion with intravenous recombinant tissue plasminogen activator (rt-PA) was the only evidence-based treatment option for a long time. Nevertheless the response rate was disappointing in large vessel occlusions. Five studies that evaluated the efficacy of mechanical thrombectomy published in 2015 proved a significant clinical benefit for selected patients suffering from acute ischemic stroke. These results are the basis for extensive technical, institutional, and personal structural changes in the neurovascular field of stroke treatment. This review gives an overview of the current status of mechanical thrombectomy and future expectations and challenges are discussed.