Effect of general anaesthesia on functional outcome in patients with anterior circulation ischaemic stroke having endovascular thrombectomy versus standard care: a meta-analysis of individual patient data

End the confusion: general anaesthesia improves patient outcomes in endovascular thrombectomy

Expert physiological and pharmacological care by anaesthetists is required in all stroke endovascular thrombectomy cases. RCTs show clinical benefits in recanalisation rates and functional recovery after endovascular thrombectomy with general anaesthesia compared with sedation. Many stroke centres will require wholesale reorganisation of stroke pathways to ensure anaesthesia services are available for all cases. Anaesthetists have an integral role in improving clinical outcomes in large vessel occlusion stroke.

Optimizing Time Management for Drip-and-Ship Stroke Patients Qualifying for Endovascular Therapy-A Single-Network Study

BACKGROUND: We sought to identify factors for delayed drip-and-ship (DS) management in stroke patients transferred from primary hospitals to our comprehensive stroke center (CSC) for endovascular therapy (EVT). METHODS: We conducted a retrospective study of all patients transferred to our CSC for EVT between 2016 and 2020. We analyzed emergency and hospital records to assess DS process times and factors predictive of delays. We dichotomized the admission period to 2016−2017 and 2018−2020 according to the main process optimization, including the introduction of a prenotification call. RESULTS: We included 869 DS patients (median age 76 years (IQR 65−82), NIHSS 16 (IQR 11−21), 278 min (IQR 243−335) from onset to EVT); 566 were transferred in 2018−2020. Admission in 2016−2017, during on-call, longer tranfer distance, and general anesthesia were factors independently associated with delayed onset to EVT time (F(5, 352) = 14.76, p < 0.000). Other factors associated with delayed DS management were: transfer mode, primary hospital type, site of large-vessel occlusion, and intravenous thrombolysis. Total transfer time was faster for distances <50 km by ambulance and for distances >71 km by helicopter. CONCLUSION: Assessment of DS processes and times throughout the patient pathway allows identification of potentially modifiable factors for improvement of the very time-critical workflow for stroke patients.

Anesthetic considerations for endovascular treatment in stroke therapy

PURPOSE OF REVIEW

The introduction of clot removement by endovascular treatment (EVT) in 2015 has improved the clinical outcome of patients with acute ischemic stroke (AIS) due to a large vessel occlusion (LVO). Anesthetic strategies during EVT vary widely between hospitals, with some departments employing local anesthesia (LA), others performing conscious sedation (CS) or general anesthesia (GA). The optimal anesthetic strategy remains debated. This review will describe the effects of anesthetic strategy on clinical and radiological outcomes and hemodynamic parameters in patients with AIS undergoing EVT.

RECENT FINDINGS

Small single-center randomized controlled trails (RCTs) found either no difference or favored GA, while large observational cohort studies favored CS or LA. RCTs using LA as separate comparator arm are still lacking and a meta-analysis of observational studies failed to show differences in functional outcome between LA vs. other anesthetic strategies. Advantages of LA were shorter door-to-groin time in patients and less intraprocedural hypotension, which are both variables that are known to impact functional outcome.

SUMMARY

The optimal anesthetic approach in patients undergoing EVT for stroke therapy is still unclear, but based on logistics and peri-procedural hemodynamics, LA may be the optimal choice. Multicenter RCTs are warranted comparing LA, CS and GS with strict blood pressure targets and use of the same anesthetic agents to minimize confounding variables.

Predictors of symptomatic intracranial hemorrhage after endovascular treatment for acute large vessel occlusion: data from ANGEL-ACT registry

Symptomatic intracranial hemorrhage (SICH) is a catastrophic complication of endovascular treatment (EVT) for large vessel occlusion (LVO). We aimed to investigate the incidence and predictors of SICH after EVT. Patients were selected from the ANGEL-ACT registry. We diagnosed SICH according to the Heidelberg Bleeding Classification. Logistic regression analyses were performed to determine the independent predictors of SICH. Of the 1283 patients, SICH was observed in 116 patients (9.0%). On multivariable analysis, admission National Institutes of Health Stroke Scale (NIHSS) > 12 (odds ratio [OR] = 1.86, 95% confidence interval [CI]: 1.11-3.11, P = 0.018), admission Alberta Stroke Program Early CT Score (ASPECTS) < 6 (OR = 2.98, 95%CI: 1.68-5.29, P < 0.001), general anesthesia (OR = 1.81, 95%CI: 1.20-2.71, P = 0.004), prior intravenous thrombolysis (OR = 1.58, 95%CI: 1.04-2.40, P = 0.031), number of mechanical thrombectomy passes > 2 (OR = 1.68, 95%CI: 1.10-2.57, P = 0.016), and procedure duration > 96 min (OR = 1.82, 95%CI: 1.20-2.77, P = 0.005) were associated with high risk of SICH, whereas SICH was negatively associated with underlying intracranial atherosclerotic disease (OR = 0.45, 95%CI: 0.26-0.79, P = 0.021). The incidence of SICH after EVT for anterior LVO was 9.0% in ANGEL-ACT registry. Our study identified some predictors, which may assist doctors in identifying LVO patients with a high risk of SICH and making the optimal peri-procedural management strategies for such patients.

Impact on functional outcome of an adaptive Stroke Unit based system of care for patients undergoing endovascular treatment during pandemic times

Introduction:

The COVID19 pandemic collapsed intensive care units (ICUs) all around the world, conditioning systems of care (SOC) for other critical conditions such as severe ischemic stroke requiring endovascular treatment (EVT). Our aim was to evaluate the impact of an adaptive Stroke Unit (SU) based SOC on functional outcomes, with the goal of avoiding both general anesthesia (GA) and ICU admission in stroke patients treated with EVT.

Material and methods:

We performed an observational study comparing data from our traditional ICU-GA based SOC and the adaptive SU-Conscious Sedation (CS) based SOC (consecutive patients undergoing EVT 1 year prior and after onset of the pandemic). Primary outcome was 90-days modified Rankin Scale (mRS), and secondary outcomes included, among others, in-hospital complications, and hospital length of stay (LOS).

Results:

A total of 210 EVT were performed during the study period (107 under the traditional-SOC and 103 under the adaptive-SOC). A significantly greater proportion of patient was treated under CS (15.9% vs 57.3%; p < 0.001) and admitted for post-procedural care at SU (15% vs 66%; p < 0.001) in the adaptive SOC. Rates of in-hospital complications were similar in both periods, with reduced hospital LOS in the adaptive SOC (10 (7–15) vs 8 (6–12); p = 0.005). The adaptive SOC was associated with higher odds for 90 days favorable outcome (mRS 0–2) (aOR 3.15 (1.34–7.39); p = 0.008).

Conclusion:

In our case, an adaptive SOC that combined both preference for CS and postprocedural care in SU was associated with better functional outcomes and reduced healthcare resource use for patients undergoing EVT.

The End of Tissue-Type Plasminogen Activator's Reign?

Mechanical thrombectomy is a highly effective treatment for acute ischemic stroke caused by large-vessel occlusion in the anterior cerebral circulation, significantly increasing the likelihood of recovery to functional independence. Until recently, whether intravenous thrombolysis before mechanical thrombectomy provided additional benefits to patients with acute ischemic stroke-large-vessel occlusion remained unclear. Given that reperfusion is a key factor for clinical outcome in patients with acute ischemic stroke-large-vessel occlusion and the efficacy of both intravenous thrombolysis and mechanical thrombectomy is time-dependent, achieving complete reperfusion with a single pass should be the primary angiographic goal. However, it remains undetermined whether extending the procedure with additional endovascular attempts or local lytics administration safely leads to higher reperfusion grades and whether there are significant public health and cost implications. Here, we outline the current state of knowledge and research avenues that remain to be explored regarding the consistent therapeutic benefit of intravenous thrombolysis in anterior circulation strokes and the potential place of adjunctive intra-arterial lytics administration, including alternative thrombolytic agent place.

Association between anesthesia modality and clinical outcomes following endovascular stroke treatment in the extended time window

BACKGROUND

There is a paucity of data on anesthesia-related outcomes for endovascular treatment (EVT) in the extended window (>6 hours from ischemic stroke onset). We compared functional and safety outcomes between local anesthesia (LA) without sedation, conscious sedation (CS) and general anesthesia (GA).

METHODS

Patients who underwent EVT in the early (<6 hours) and extended time windows using LA, CS, or GA between October 2015 and March 2020 were included from a UK national stroke registry. Multivariable analyses were performed, adjusted for age, sex, baseline stroke severity, pre-stroke disability, EVT technique, center, procedural time and IV thrombolysis.

RESULTS

A total of 4337 patients were included, 3193 in the early window (1135 LA, 446 CS, 1612 GA) and 1144 in the extended window (357 LA, 134 CS, 653 GA). Compared with GA, patients treated under LA alone had increased odds of an improved modified Rankin Scale (mRS) score at discharge (early: adjusted common (ac) OR=1.50, 95% CI 1.29 to 1.74, p=0.001; extended: acOR=1.29, 95% CI 1.01 to 1.66, p=0.043). Similar mRS scores at discharge were found in the LA and CS cohorts in the early and extended windows (p=0.21). Compared with CS, use of GA was associated with a worse mRS score at discharge in the early window (acOR=0.73, 95% CI 0.45 to 0.96, p=0.017) but not in the extended window (p=0.55). There were no significant differences in the rates of symptomatic intracranial hemorrhage or in-hospital mortality across the anesthesia modalities in the extended window.

CONCLUSION

LA without sedation during EVT was associated with improved functional outcomes compared with GA, but not CS, within and beyond 6 hours from stroke onset. Prospective studies assessing anesthesia-related outcomes in the extended time window are warranted.

Endovascular Treatment for Acute Ischemic Stroke With or Without General Anesthesia: A Matched Comparison

BACKGROUND

Endovascular treatment in large artery occlusion stroke reduces disability. However, the impact of anesthesia type on clinical outcomes remains uncertain.

METHODS

We compared consecutive patients in the Swiss Stroke Registry with anterior circulation stroke receiving endovascular treatment with or without general anesthesia (GA). The primary outcome was disability on the modified Rankin Scale after 3 months, analyzed with ordered logistic regression. Secondary outcomes included dependency or death (modified Rankin Scale score ≥3), National Institutes of Health Stroke Scale after 24 hours, symptomatic intracranial hemorrhage with ≥4 points worsening on National Institutes of Health Stroke Scale within 7 days, and mortality. Coarsened exact matching and propensity score matching were performed to adjust for indication bias.

RESULTS

One thousand two hundred eighty-four patients (GA: n=851, non-GA: n=433) from 8 Stroke Centers were included. Patients treated with GA had higher modified Rankin Scale scores after 3 months than patients treated without GA, in the unmatched (odds ratio [OR], 1.75 [1.42-2.16]; P<0.001), the coarsened exact matching (n=332-524, using multiple imputations of missing values; OR, 1.60 [1.08-2.36]; P=0.020), and the propensity score matching analysis (n=568; OR, 1.61 [1.20-2.15]; P=0.001). In the coarsened exact matching analysis, there were no significant differences in National Institutes of Health Stroke Scale after 1 day (estimated coefficient 2.61 [0.59-4.64]), symptomatic intracranial hemorrhage (OR, 1.06 [0.30-3.75]), dependency or death (OR, 1.42 [0.91-2.23]), or mortality (OR, 1.65 [0.94-2.89]). In the propensity score matching analysis, National Institutes of Health Stroke Scale after 24 hours (estimated coefficient, 3.40 [1.76-5.04]), dependency or death (OR, 1.49 [1.07-2.07]), and mortality (OR, 1.65 [1.11-2.45]) were higher in the GA group, whereas symptomatic intracranial hemorrhage did not differ significantly (OR, 1.77 [0.73-4.29]).

CONCLUSIONS

This large study showed worse functional outcome after endovascular treatment of anterior circulation stroke with GA than without GA in a real-world setting. This finding appears to be independent of known differences in patient characteristics between groups.

General Anesthesia versus Sedation, Both with Hemodynamic Control, during Intraarterial Treatment for Stroke: The GASS Randomized Trial

BACKGROUND

It is speculated that the anesthetic strategy during endovascular therapy for stroke may have an impact on the outcome of the patients. The authors hypothesized that conscious sedation is associated with a better functional outcome 3 months after endovascular therapy for the treatment of stroke compared with general anesthesia.

METHODS

In this single-blind, randomized trial, patients received either a standardized general anesthesia or a standardized conscious sedation. Blood pressure control was also standardized in both groups. The primary outcome measure was a modified Rankin score less than or equal to 2 (0 = no symptoms; 5 = severe disability) assessed 3 months after treatment. The main secondary outcomes were complications, mortality, reperfusion results, and National Institutes of Health Stroke Scores at days 1 and 7.

RESULTS

Of 351 randomized patients, 345 were included in the analysis. The primary outcome occurred in 129 of 341 (38%) of the patients: 63 (36%) in the conscious sedation group and 66 (40%) in the general anesthesia group (relative risk, 0.91 [95% CI, 0.69 to 1.19]; P = 0.474). Patients in the general anesthesia group experienced more intraoperative hypo- or hypertensive episodes, while the cumulative duration was not different (mean ± SD, 36 ± 31 vs. 39 ± 25 min; P = 0.079). The time from onset and from arrival to puncture were longer in the general anesthesia group (mean difference, 19 min [i.e., -00:19] [95% CI, -0:38 to 0] and mean difference, 9 min [95% CI, -0:18 to -0:01], respectively), while the time from onset to recanalization was similar in both groups. Recanalization was more often successful in the general anesthesia group (144 of 169 [85%] vs. 131 of 174 [75%]; P = 0.021). The incidence of symptomatic intracranial hemorrhage was similar in both groups.

CONCLUSIONS

The functional outcomes 3 months after endovascular treatment for stroke were similar with general anesthesia and sedation. Our results, therefore, suggest that clinicians can use either approach.

EDITOR’S PERSPECTIVE

Functional assessment of bidirectional cortical and peripheral neural control on heartbeat dynamics: a brain-heart study on thermal stress

The study of functional brain-heart interplay (BHI) from non-invasive recordings has gained much interest in recent years. Previous endeavors aimed at understanding how the two dynamical systems exchange information, providing novel holistic biomarkers and important insights on essential cognitive aspects and neural system functioning. However, the interplay between cardiac sympathovagal and cortical oscillations still has much room for further investigation. In this study, we introduce a new computational framework for a functional BHI assessment, namely the Sympatho-Vagal Synthetic Data Generation Model, combining cortical (electroencephalography, EEG) and peripheral (cardiac sympathovagal) neural dynamics. The causal, bidirectional neural control on heartbeat dynamics was quantified on data gathered from 26 human volunteers undergoing a cold-pressor test. Results show that thermal stress induces heart-to-brain functional interplay sustained by EEG oscillations in the delta and gamma bands, primarily originating from sympathetic activity, whereas brain-to-heart interplay originates over central brain regions through sympathovagal control. The proposed methodology provides a viable computational tool for the functional assessment of the causal interplay between cortical and cardiac neural control.

General Anesthesia vs. Local Anesthesia During Endovascular Treatment for Acute Large Vessel Occlusion: A Propensity Score-Matched Analysis

Objective

To date, no consensus still exists on the anesthesia strategy of endovascular treatment (EVT) for acute ischemic stroke (AIS) due to large vessel occlusion (LVO). We aimed to compare the 90-day outcomes, puncture-to-recanalization time (PRT), successful recanalization rate, and symptomatic intracranial hemorrhage (sICH) of patients undergoing general anesthesia (GA) or local anesthesia (LA) ± conscious sedation (CS) during the procedure.

Methods

We selected patients from the Acute Ischemic Stroke Cooperation Group of Endovascular Treatment (ANGEL) registry and divided them into the GA group and the LA ± CS group. The two groups underwent 1:1 matching under propensity score matching (PSM) analysis. Then, we compared the primary outcome including the 90-day modified Rankin Scale (mRS) 0–2, secondary outcome including the 90-day mRS, the 90-day mRS 0–1, the 90-day mRS 0–3, PRT, and successful recanalization rate as well as the safety outcome including sICH, any ICH, and 90-day mRS 6.

Results

Among the 705 enrolled patients, 263 patients underwent GA and 442 patients underwent LA ± CS. After 1:1 PSM according to the baseline characteristics, each group has 216 patients. Patients with GA had the higher median 90-day mRS [3 (1–5) vs. 2 (1–4), p < 0.001], the lower 90-day mRS 0–2 rate (43.5 vs. 56.5%, p = 0.007), higher mortality (19.9 vs.10.2%, p = 0.005), and longer PRT [92 (60–140) vs. 70 (45–103) min, p < 0.001]. There were no differences in sICH and successful recanalization rate between both the groups.

Conclusion

In the real-world setting, LA ± CS might provide more outcomes benefits than GA in patients with AIS-LVO during the procedure.

Team Prenotification Reduces Procedure Times for Patients With Acute Ischemic Stroke Due to Large Vessel Occlusion Who Are Transferred for Endovascular Therapy

Background: The clinical benefit from endovascular therapy (EVT) for patients with acute ischemic stroke is time-dependent. We tested the hypothesis that team prenotification results in faster procedure times prior to initiation of EVT.

Methods: We analyzed data from our prospective database (01/2016–02/2018) including all patients with acute ischemic stroke who were evaluated for EVT at our comprehensive stroke center. We established a standardized algorithm (EVT-Call) in 06/2017 to prenotify team members (interventional neuroradiologist, neurologist, anesthesiologist, CT and angiography technicians) about patient transfer from remote hospitals for evaluation of EVT, and team members were present in the emergency department at the expected patient arrival time. We calculated door-to-image, image-to-groin and door-to-groin times for patients who were transferred to our center for evaluation of EVT, and analyzed changes before (–EVT-Call) and after (+EVT-Call) implementation of the EVT-Call.

Results: Among 494 patients in our database, 328 patients were transferred from remote hospitals for evaluation of EVT (208 -EVT-Call and 120 +EVT-Call, median [IQR] age 75 years [65–81], NIHSS score 17 [12–22], 49.1% female). Of these, 177 patients (54%) underwent EVT after repeated imaging at our center (111/208 [53%) -EVT-Call, 66/120 [55%] +EVT-Call). Median (IQR) door-to-image time (18 min [14–22] vs. 10 min [7–13]; p < 0.001), image-to-groin time (54 min [43.5–69.25] vs. 47 min [38.3–58.75]; p = 0.042) and door-to-groin time (74 min [58–86.5] vs. 60 min [49.3–71]; p < 0.001) were reduced after implementation of the EVT-Call.

Conclusions: Team prenotification results in faster patient assessment and initiation of EVT in patients with acute ischemic stroke. Its impact on functional outcome needs to be determined.

Monitored anesthesia care during mechanical thrombectomy for stroke: need for data-driven and individualized decisions

BACKGROUND

The optimal anesthesia management for patients with stroke undergoing mechanical thrombectomy (MT) during the COVID-19 pandemic has become a matter of controversy. Some recent guidelines have favored general anesthesia (GA) in patients perceived as high risk for intraprocedural conversion from sedation to GA, including those with dominant hemispheric occlusions/aphasia or baseline National Institutes of Health Stroke Scale (NIHSS) score >15. We aim to identify the rate and predictors of conversion to GA during MT in a high-volume center where monitored anesthesia care (MAC) is the default modality.

METHODS

A retrospective review of a prospectively maintained MT database from January 2013 to July 2020 was undertaken. Analyses were conducted to identify the predictors of intraprocedural conversion to GA. In addition, we analyzed the GA conversion rates in subgroups of interest.

RESULTS

Among 1919 MT patients, 1681 (87.6%) started treatment under MAC (median age 65 years (IQR 55-76); baseline NIHSS 16 (IQR 11-21); 48.4% women). Of the 1677 eligible patients, 26 (1.6%) converted to GA including 1.4% (22/1615) with anterior and 6.5% (4/62) with posterior circulation strokes. The only predictor of GA conversion was posterior circulation stroke (OR 4.99, 95% CI 1.67 to 14.96, P=0.004). The conversion rates were numerically higher in right than in left hemispheric occlusions (1.6% vs 1.2%; OR 1.37, 95% CI 0.59 to 3.19, P=0.47) and in milder than in more severe strokes (NIHSS ≤15 vs >15: 2% vs 1.2%; OR 0.62, 95% CI 0.28 to 1.36, P=0.23).

CONCLUSIONS

Our study showed that the overall rate of conversion from MAC to GA during MT was low (1.6%) and, while higher in posterior circulation strokes, it was not predicted by either hemispheric dominance or stroke severity. Caution should be given before changing clinical practice during moments of crisis.

Periprocedural Management During Stroke Thrombectomy

PURPOSE OF REVIEW

Endovascular therapy (EVT) for acute ischemic stroke caused by large vessel occlusion is a powerful and evidence-based tool to achieve reperfusion and results in improved neurologic outcome. Focus has now shifted toward optimizing the procedure. We reviewed the relevant current literature on periprocedural stroke care such as pretreatment with IV tissue plasminogen activator (tPA), choice of anesthesia, ventilation strategy, and blood pressure management.

RECENT FINDINGS

IV tPA should not be withheld in a patients with stroke eligible for EVT. A meta-analysis of randomized trials on general anesthesia (GA) vs procedural sedation has shown better neurologic outcomes with protocol-based GA in centers with dedicated neuroanesthesia teams. There are no data from randomized trials on blood pressure control, but according to available evidence, systolic blood pressure should probably be held at >140 mm Hg during the procedure and <160 mm Hg after reperfusion. In ventilated patients, extreme deviations from normoxemia and normocapnia should be avoided.

SUMMARY

Periprocedural care influences the outcome after EVT for large vessel ischemic stroke. More evidence from prospective ongoing and future studies is urgently needed to identify its optimization.

Impact of anesthetic strategy on outcomes for patients with acute basilar artery occlusion undergoing mechanical thrombectomy

BACKGROUND

The best anesthetic management strategy for patients with acute large vessel occlusion treated with mechanical thrombectomy (MT) remains uncertain. Most studies have focused on anterior-circulation stroke caused by large artery occlusion. Nevertheless, limited data are available on the appropriate choice of anesthetic for acute basilar artery occlusion (BAO). We aimed to investigate the effect of anesthetic method on clinical outcomes in patients with BAO undergoing MT.

METHODS

Patients undergoing MT for acute BAO in the BASILAR registry (Acute Basilar Artery Occlusion Study) were included. We divided patients into three groups according to the anesthetic technique used during MT: general anesthesia (GA), local anesthesia (LA), and conscious sedation (CS). Propensity score matching was performed to achieve baseline balance.

RESULTS

639 patients were included. GA was used in 257 patients (40.2%), LA was used in 250 patients (39.1%), and CS was used in 132 patients (20.7%). After 1:1 matching, favorable outcome, mortality, and hemorrhagic transformation rates, as well as modified Rankin Scale (mRS) score at 90 days, did not differ between the GA, LA, and CS groups.

CONCLUSIONS

The choice of anesthetic strategy, GA, LA, or CS, did not affect the clinical outcomes of patients with acute BAO treated with MT in the BASILAR registry.

Serum neurofilament light chain levels are associated with stroke severity and functional outcome in patients undergoing endovascular therapy for large vessel occlusion

BACKGROUND

We aimed to analyze serum neurofilament light chain (sNfL) levels in patients undergoing endovascular therapy (EVT) for anterior circulation large vessel occlusion (acLVO).

METHODS

Prospective study of consecutive patients with acLVO receiving EVT (12/2020-01/2021). sNfL was serially measured prior to and at 30-min, 6-h, 12-h, 24-h, 48-h and 7-days following EVT. ANOVA and Spearman correlation were run to assess sNfL levels (ie, absolute values) and ΔsNfL levels (ie, absolute values subtracted by baseline value) and their association with clinical (ie, NIHSS), imaging (ie, ASPECTS) surrogates of stroke severity as well as functional outcome (ie, mRS) at 90-days.

RESULTS

175 sNfL samples were retrieved from 25 patients. While there were no differences among serial sNfL levels in the first 12-h post-EVT, a constant increase was observed afterwards (maximum day 7, median: 383 [IQR, 209-907] pg/mL, p < 0.001). ΔsNfL showed a constant increase from 30-min measurement onwards peaking after 7 days (median 363.5 [IQR, 114.3-851.1] pg/mL). sNfL levels at 7 days correlated with ASPECTS post-EVT (r = -0.59, p < 0.001), NIHSS at discharge (r = -0.50, p = 0.011) and mRS at 90-days (r = 0.45, p = 0.027).

CONCLUSIONS

Serum NFL may complement established clinical and imaging predictors of treatment response and functional outcome in stroke patients undergoing EVT for acLVO.

Oxygen Saturation and Postoperative Mortality in Patients With Acute Ischemic Stroke Treated by Endovascular Thrombectomy

BACKGROUND

Monitored anesthesia care (MAC) and general anesthesia (GA) with endotracheal intubation are the 2 most used techniques for patients with acute ischemic stroke (AIS) undergoing endovascular thrombectomy. We aimed to test the hypothesis that increased arterial oxygen concentration during reperfusion period is a mechanism underlying the association between use of GA (versus MAC) and increased risk of in-hospital mortality.

METHODS

In this retrospective cohort study, data were collected at the Cleveland Clinic between 2013 and 2018. To assess the potential mediation effect of time-weighted average oxygen saturation (Spo2) in first postoperative 48 hours between the association between GA versus MAC and in-hospital mortality, we assessed the association between anesthesia type and post-operative Spo2 tertiles (exposure-mediator relationship) through a cumulative logistic regression model and assessed the association between Spo2 and in-hospital mortality (mediator-outcome relationship) using logistic regression models. Confounding factors were adjusted for using propensity score methods. Both significant exposure-mediator and significant mediator-outcome relationships are needed to suggest potential mediation effect.

RESULTS

Among 358 patients included in the study, 104 (29%) patients received GA and 254 (71%) received MAC, with respective hospital mortality rate of 19% and 5% (unadjusted P value <.001). GA patients were 1.6 (1.2, 2.1) (P < .001) times more likely to have a higher Spo2 tertile as compared to MAC patients. Patients with higher Spo2 tertile had 3.8 (2.1, 6.9) times higher odds of mortality than patients with middle Spo2 tertile, while patients in the lower Spo2 tertile did not have significant higher odds compared to the middle tertile odds ratio (OR) (1.8 [0.9, 3.4]; overall P < .001). The significant exposure-mediator and mediator-outcome relationships suggest that Spo2 may be a mediator of the relationship between anesthetic method and mortality. However, the estimated direct effect of GA versus MAC on mortality (ie, after adjusting for Spo2; OR [95% confidence interval {CI}] of 2.1 [0.9-4.9]) was close to the estimated association ignoring Spo2 (OR [95% CI] of 2.2 [1.0-5.1]), neither statistically significant, suggesting that Spo2 had at most a modest mediator role.

CONCLUSIONS

GA was associated with a higher Spo2 compared to MAC among those treated by endovascular thrombectomy for AIS. Spo2 values that were higher than the middle tertile were associated with higher odds of mortality. However, GA was not significantly associated with higher odds of death. Spo2 at most constituted a modest mediator role in explaining the relationship between GA versus MAC and mortality.

Impact of general anesthesia on posterior circulation large vessel occlusions after endovascular thrombectomy

Background

The impact of general anesthesia on functional outcome in patients with large vessel occlusion remains unclear. Most studies have focused on anterior circulation large vessel occlusion; however, little is known about the effect of general anesthesia in patients with posterior circulation—large vessel occlusion.

Methods

We performed a retrospective analysis from the prospective CICAT registry. All patients with posterior circulation—large vessel occlusion—and undergoing endovascular therapy between January 2016 and January 2020 were included. Demographics, baseline characteristics, procedural data, and anesthesia modality (general anesthesia or conscious sedation) were evaluated. The primary outcome was the proportion of patients with good clinical outcome (modified Rankin Scale score of 0–2) at three months.

Results

298 patients underwent endovascular treatment with posterior circulation—large vessel occlusion—were included. Age, diabetes mellitus, renal insufficiency, baseline National Institutes of Health Stroke Scale score, puncture to recanalization length, ≥3 device passes, absent of successful recanalization (defined as treatment in cerebral ischemia of 3), and general anesthesia were statistically associated with poor outcome (mRS: 3-6). In the multivariable regression, general anesthesia and ≥3 device passes were independently associated with poor outcome (aOR: 3.11, (95% CI: 1.34–7.2); P = 0.01 and 3.77, (95% CI: 1.29–11.01); P = 0.02, respectively). Patients treated with general anesthesia were less likely to have a good outcome at three months compared to conscious sedation (19.7% vs. 45.1%, P < 0.001).

Conclusions

In our study population, general anesthesia use is associated with poor clinical outcome in patients with posterior circulation—large vessel occlusion—treated endovascularly.

Unexplained early neurological deterioration after endovascular treatment for acute large vessel occlusion: incidence, predictors, and clinical impact: Data from ANGEL-ACT registry

BACKGROUND

Early neurological deterioration (END) may occur in some patients with acute large vessel occlusion (LVO) undergoing endovascular treatment (EVT). Despite several clear causes of END, such as symptomatic intracranial hemorrhage, failure of recanalization, and intraprocedure complications, a particular END, termed unexplained END (END_unexplained), exists. We aimed to investigate the incidence, independent predictors, and clinical impact of END_unexplained after EVT in patients with acute LVO.

METHODS

Subjects were selected from the ANGEL-ACT registry. END_unexplained was defined as ≥4-point increase in the National Institutes of Health Stroke Scale (NIHSS) score between baseline and 24 hours after EVT, without the causes listed above. Logistic regression analyses were performed to determine the independent predictors of END_unexplained, as well as the association between END_unexplained and 90-day outcomes assessed by modified Rankin Scale (mRS) score.

RESULTS

Among the 1557 enrolled patients, the incidence of END_unexplained was 4.3% (67/1557). Admission NIHSS ≤8 (OR=6.88, 95% CI 3.86 to 12.26, p<0.001), general anesthesia (OR=3.15, 95% CI 1.81 to 5.48, p<0.001), admission neutrophil to lymphocyte ratio >5 (OR=2.82, 95% CI 1.61 to 4.94, p<0.001), and number of EVT attempts >3 (OR=2.11, 95% CI 1.14 to 3.89, p=0.018) were associated independently with a high risk of END_unexplained. Furthermore, patients with END_unexplained were associated with a shift toward worse 90-day outcomes (mRS 5 vs 3, common OR=5.24, 95% CI 3.22 to 8.52, p<0.001).

CONCLUSIONS

END_unexplained associated with poor 90day outcomes occurred in 4.3% of patients with acute LVO undergoing EVT. Several independent predictors of END_unexplained were identified in this study, which should be considered in daily practice to improve acute LVO management.

CLINICAL TRIAL REGISTRATION

http://wwwclinicaltrialsgov NCT03370939.

In silico trials for treatment of acute ischemic stroke: Design and implementation

An in silico trial simulates a disease and its corresponding therapies on a cohort of virtual patients to support the development and evaluation of medical devices, drugs, and treatment. In silico trials have the potential to refine, reduce cost, and partially replace current in vivo studies, namely clinical trials and animal testing. We present the design and implementation of an in silico trial for treatment of acute ischemic stroke. We propose an event-based modelling approach for the simulation of a disease and injury, where changes to the state of the system (the events) are assumed to be instantaneous. Using this approach we are able to combine a diverse set of models, spanning multiple time scales, to model acute ischemic stroke, treatment, and resulting brain tissue injury. The in silico trial is designed to be modular to aid development and reproducibility. It provides a comprehensive framework for application to any potential in silico trial. A statistical population model is used to generate cohorts of virtual patients. Patient functional outcomes are also predicted with a statistical model, using treatment and injury results and the patient's clinical parameters. We demonstrate the functionality of the event-based modelling approach and trial framework by running proof of concept in silico trials. The proof of concept trials simulate the same cohort of patients twice: once with successful treatment (successful recanalisation) and once with unsuccessful treatment (unsuccessful treatment). Ways to overcome some of the challenges and difficulties in setting up such an in silico trial are discussed, such as validation and computational limitations.

Is General Anesthesia for Endovascular Thrombectomy Helpful or Harmful?

Endovascular thrombectomy (EVT) has significantly improved outcomes for patients with acute ischemic stroke due to large vessel occlusion. However, despite advances, more than half of patients remain functionally dependent 3 months after their initial stroke. Anesthetic strategy may influence both the technical success of the procedure and overall outcomes. Conventionally, general anesthesia (GA) has been widely used for neuroendovascular procedures, particularly for the distal intracranial circulation, because the complete absence of movement has been considered imperative for procedural success and to minimize complications. In contrast, in patients with acute stroke undergoing EVT, the optimal anesthetic strategy is controversial. Nonrandomized studies suggest GA negatively affects outcomes while the more recent anesthesia-specific RCTs report improved or unchanged outcomes in patients managed with versus without GA, although these findings cannot be generalized to other EVT capable centers due to a number of limitations. Potential explanations for these contrasting results will be addressed in this review including the effect of different anesthetic strategies on cerebral and systemic hemodynamics, revascularization times, and periprocedural complications.

General anesthesia during endovascular therapy for acute ischemic stroke: benefits beyond better reperfusion?

BACKGROUND

Endovascular therapy (EVT) is standard of care for stroke caused by large vessel occlusion. Whether EVT should be performed under general anesthesia (GA) or conscious sedation (CS) is controversial. While a meta-analysis of randomized trials showed better outcome for EVT under GA, observational studies suggested the opposite. A proposed advantage of GA is better reperfusion achieved via more successful handling of the immobile patient. The aim of this study was to investigate if the good outcome seen in patients treated under GA was mediated by better reperfusion.

METHODS

The meta-analysis included 368 individual patients from three randomized controlled trials, of whom 185 patients were randomized to CS. A mediator analysis was performed to examine if the better outcome in the GA arm was driven by higher reperfusion rate.

RESULTS

The total effect showed a risk difference (RD) of 0.15 (95% CI 0.04 to 0.25), associating GA with a beneficial outcome. The direct effect of GA constituted a large portion, with an RD of 0.12 (95% CI 0.01 to 0.22), while only a small portion was mediated through the degree of reperfusion, with an RD of 0.03 (95% CI 0.02 to 0.04).

CONCLUSION

The better outcome after EVT in the GA arm was mainly a direct effect-that is, an effect that was not explained by better reperfusion. We also found a better outcome in the GA arm when reperfusion was not achieved. Whether this is an effect of the stable condition and blood pressure under GA or a neuroprotective effect will need to be investigated in future research.

Hypotension during endovascular treatment under general anesthesia for acute ischemic stroke

Objective

The effect of anesthetic management (general anesthesia [GA], conscious sedation, or local anesthesia) on functional outcome and the role of blood pressure management during endovascular treatment (EVT) for acute ischemic stroke is under debate. We aimed to determine whether hypotension during EVT under GA is associated with functional outcome at 90 days.

Methods

We retrospectively collected data from patients with a proximal intracranial occlusion of the anterior circulation treated with EVT under GA. The primary outcome was the distribution on the modified Rankin Scale at 90 days. Hypotension was defined using two thresholds: a mean arterial pressure (MAP) of 70 mm Hg and a MAP 30% below baseline MAP. To quantify the extent and duration of hypotension, the area under the threshold (AUT) was calculated using both thresholds.

Results

Of the 366 patients included, procedural hypotension was observed in approximately half of them. The occurrence of hypotension was associated with poor functional outcome (MAP <70 mm Hg: adjusted common odds ratio [acOR], 0.57; 95% confidence interval [CI], 0.35–0.94; MAP decrease ≥30%: acOR, 0.76; 95% CI, 0.48–1.21). In addition, an association was found between the number of hypotensive periods and poor functional outcome (MAP <70 mm Hg: acOR, 0.85 per period increase; 95% CI, 0.73–0.99; MAP decrease ≥30%: acOR, 0.90 per period; 95% CI, 0.78–1.04). No association existed between AUT and functional outcome (MAP <70 mm Hg: acOR, 1.000 per 10 mm Hg*min increase; 95% CI, 0.998–1.001; MAP decrease ≥30%: acOR, 1.000 per 10 mm Hg*min; 95% CI, 0.999–1.000).

Conclusions

Occurrence of procedural hypotension and an increase in number of procedural hypotensive periods were associated with poor functional outcome, whereas the extent and duration of hypotension were not. Randomized clinical trials are needed to confirm our hypothesis that hypotension during EVT under GA has detrimental effects.

Inadvertent hypothermia after endovascular therapy is not associated with improved outcome in stroke due to anterior circulation large vessel occlusion

BACKGROUND AND PURPOSE

Hypothermia may be neuroprotective in acute ischemic stroke. Patients with anterior circulation large vessel occlusion (acLVO) are frequently hypothermic after endovascular therapy (EVT). We sought to determine whether this inadvertent hypothermia is associated with improved outcome.

METHODS

We extracted data of consecutive patients (January 2016 to May 2019) who received EVT for acLVO from our prospective EVT register of all patients screened for EVT at our tertiary stroke center. We assessed functional outcome at 3 months and performed multivariate analysis to calculate adjusted risk ratios (aRRs) for favorable outcome (modified Rankin Scale scores = 0-2) and mortality across patients who were hypothermic (<36°C) and patients who were normothermic (≥36°C to <37.6°C) after EVT. Moreover, we compared the frequency of complications between these groups.

RESULTS

Among 837 patients screened, 416 patients received EVT for acLVO and fulfilled inclusion criteria (200 [48.1%] male, mean age = 76 ± 16 years, median National Institutes of Health Stroke Scale score = 16, interquartile range [IQR] = 12-20). Of these, 209 patients (50.2%) were hypothermic (median temperature = 35.2°C, IQR = 34.7-35.7) and 207 patients were normothermic (median temperature = 36.4°C, IQR = 36.1-36.7) after EVT. In multivariate analysis, hypothermia was not associated with favorable outcome (aRR = 0.99, 95% confidence interval [CI] = 0.75-1.31) and mortality (aRR = 1.18, 95% CI = 0.84-1.66). More hypothermic patients suffered from pneumonia (36.4% vs. 25.6%, p = 0.02) and bradyarrhythmia (52.6% vs. 16.4%, p < 0.001), whereas thromboembolic events were distributed evenly (5.7% vs. 6.8%, not significant).

CONCLUSIONS

Inadvertent hypothermia after EVT for acLVO is not associated with improved functional outcome or reduced mortality but is associated with an increased rate of pneumonia and bradyarrhythmia in patients with acute ischemic stroke.

Compliance With Preferred Reporting Items for Systematic Review and Meta-Analysis Individual Participant Data Statement for Meta-Analyses Published for Stroke Studies

[Figure: see text].

Healthy Life-Year Costs of Treatment Speed From Arrival to Endovascular Thrombectomy in Patients With Ischemic Stroke: A Meta-analysis of Individual Patient Data From 7 Randomized Clinical Trials

Importance

The benefits of endovascular thrombectomy (EVT) are time dependent. Prior studies may have underestimated the time-benefit association because time of onset is imprecisely known.

Objective

To assess the lifetime outcomes associated with speed of endovascular thrombectomy in patients with acute ischemic stroke due to large-vessel occlusion (LVO).

Data Sources

PubMed was searched for randomized clinical trials of stent retriever thrombectomy devices vs medical therapy in patients with anterior circulation LVO within 12 hours of last known well time, and for which a peer-reviewed, complete primary results article was published by August 1, 2020.

Study Selection

All randomized clinical trials of stent retriever thrombectomy devices vs medical therapy in patients with anterior circulation LVO within 12 hours of last known well time were included.

Data Extraction/Synthesis

Patient-level data regarding presenting clinical and imaging features and functional outcomes were pooled from the 7 retrieved randomized clinical trials of stent retriever thrombectomy devices (entirely or predominantly) vs medical therapy. All 7 identified trials published in a peer-reviewed journal (by August 1, 2020) contributed data. Detailed time metrics were collected including last known well-to-door (LKWTD) time; last known well/onset-to-puncture (LKWTP) time; last known well-to-reperfusion (LKWR) time; door-to-puncture (DTP) time; and door-to-reperfusion (DTR) time.

Main Outcomes and Measures

Change in healthy life-years measured as disability-adjusted life-years (DALYs). DALYs were calculated as the sum of years of life lost (YLL) owing to premature mortality and years of healthy life lost because of disability (YLD). Disability weights were assigned using the utility-weighted modified Rankin Scale. Age-specific life expectancies without stroke were calculated from 2017 US National Vital Statistics.

Results

Among the 781 EVT-treated patients, 406 (52.0%) were early-treated (LKWTP ≤4 hours) and 375 (48.0%) were late-treated (LKWTP >4-12 hours). In early-treated patients, LKWTD was 188 minutes (interquartile range, 151.3-214.8 minutes) and DTP 105 minutes (interquartile range, 76-135 minutes). Among the 298 of 380 (78.4%) patients with substantial reperfusion, median DTR time was 145.0 minutes (interquartile range, 111.5-185.5 minutes). Care process delays were associated with worse clinical outcomes in LKW-to-intervention intervals in early-treated patients and in door-to-intervention intervals in early-treated and late-treated patients, and not associated with LKWTD intervals, eg, in early-treated patients, for each 10-minute delay, healthy life-years lost were DTP 1.8 months vs LKWTD 0.0 months; P < .001. Considering granular time increments, the amount of healthy life-time lost associated with each 1 second of delay was DTP 2.2 hours and DTR 2.4 hours.

Conclusions and Relevance

In this study, care delays were associated with loss of healthy life-years in patients with acute ischemic stroke treated with EVT, particularly in the postarrival time period. The finding that every 1 second of delay was associated with loss of 2.2 hours of healthy life may encourage continuous quality improvement in door-to-treatment times.

Emergency intubation during thrombectomy for acute ischemic stroke in patients under primary procedural sedation

Background

Emergency intubation is an inherent risk of procedural sedation regimens for endovascular treatment (EVT) of acute ischemic stroke. We aimed to characterize the subgroup of patients, who had to be emergently intubated, to identify predictors of the need for intubation and assess their outcomes.

Methods

This is a retrospective analysis of the single-center study KEEP SIMPLEST, which evaluated a new in-house SOP for EVT under primary procedural sedation. We used descriptive statistics and regression models to examine predictors and functional outcome of emergently intubated patients.

Results

Twenty of 160 (12.5%) patients were emergently intubated. National Institutes of Health Stroke Scale (NIHSS) on admission, premorbid modified Rankin scale (mRS), Alberta Stroke Program Early CT Score, age and side of occlusion were not associated with need for emergency intubation. Emergency intubation was associated with a lower rate of successful reperfusion (OR, 0.174; 95%-CI, 0.045 to 0.663; p = 0.01). Emergently intubated patients had higher in-house mortality (30% vs 6.4%; p = 0.001) and a lower rate of mRS 0–2 at 3 months was observed in those patients (10.5% vs 37%, p = 0.024).

Conclusions

Emergency intubation during a primary procedural sedation regimen for EVT was associated with lower rate of successful reperfusion. Less favorable outcome was observed in the subgroup of emergently intubated patients. More research is required to find practical predictors of intubation need and to determine, whether emergency intubation is safe under strict primary procedural sedation regimens for EVT.

Supplementary Information

The online version contains supplementary material available at 10.1186/s42466-021-00125-0.

Initial Management of Patients with Suspected Stroke in the SARS-CoV-2 Era: Effects on the Door-to-Picture Time

Objective

To examine the effectiveness of a newly developed emergency room (ER) protocol to treat patients with stroke and control the spread of SARS-CoV-2 by evaluating the door-to-picture time.

Methods

We retrospectively enrolled 126 patients who were transported to our ER by ambulance with suspected stroke between April 15 and October 31, 2020 (study group). A risk judgment system named the COVID level was introduced to classify the risk of infection as follows: level 0, no infection; I, infection unlikely; II, possible; III, probable; and IV, definite. Patients with COVID levels 0, I, or II and a Glasgow Coma Scale (GCS) score >10 were placed in a normal ER (nER) without atmospheric pressure control; the medical staff wore standard personal protective equipment (PPE) in such cases. Patients with COVID level II, III, or IV, and a GCS score of ≤10 were assigned to the negative pressure ER (NPER); the medical staff wore enhanced PPE for these cases. The validity of the protocol was assessed. The door-to-picture time of the study group was compared with that of 114 control patients who were transported with suspected stroke during the same period in 2019 (control group). The difference in the time for CT and MRI between the two groups was also compared. In the study group, the time spent in the nER and NPER was evaluated.

Results

In all, 118 patients (93.7%) were classified as level I, 6 (4.8%) as level II, and 2 (1.6%) as level III. Only five patients (4.0%) were treated with NPER. Polymerase chain reaction tests were performed on 118 out of 126 patients (93.7%) and were negative. No significant differences were observed in age, sex, neurological severity, modalities of diagnostic imaging, and diagnosis compared with the control group. The median door-to-picture time was 18 (11-27.8) min in the study group and 15 (10-25) min in the control group (p = 0.08). No delay was found on CT (15 [10-21] vs. 14 [9-21] min, p = 0.24). In contrast, there was an 8-min delay for MRI (30 [21.8-50] vs. 22 [14-30] min, p = 0.01). The median door-to-picture time was 29 min longer in patients treated with NPER than in those treated with nER, although the difference was not significant due to the small number of patients (47 [27-57] vs. 18 [11-26] min, p = 0.07).

Conclusion

Our protocol could optimize the use of medical resources with only a 3-min delay in the door-to-picture time in an area without explosive outbreak. Unfortunately, the effectiveness of the protocol in preventing infection could not be verified because of the low incidence of COVID-19. When developing and modifying an institutional protocol, recognizing the outbreak status surrounding each institution is important.

Factors Influencing Recanalization After Mechanical Thrombectomy With First-Pass Effect for Acute Ischemic Stroke: A Systematic Review and Meta-Analysis

Background: First-pass effect (FPE) is increasingly recognized as a predictor of good outcome in large vessel occlusion (LVO). This systematic review and meta-analysis aimed to elucidate the factors influencing recanalization after mechanical thrombectomy (MT) with FPE in treating acute ischemic stroke (AIS).

Methods: Main databases were searched for relevant randomized controlled trials (RCTs) and observational studies reporting influencing factors of MT with FPE in AIS. Recanalization was assessed by the modified thrombolysis in cerebral ischemia (mTICI) score. Both successful (mTICI 2b-3) and complete recanalization (mTICI 2c-3) were observed. Risk of bias was assessed through different scales according to study design. The I² statistic was used to evaluate the heterogeneity, while subgroup analysis, meta-regression, and sensitivity analysis were performed to investigate the source of heterogeneity. Visual measurement of funnel plots was used to evaluate publication bias.

Results: A total of 17 studies and 6,186 patients were included. Among them, 2,068 patients achieved recanalization with FPE. The results of meta-analyses showed that age [mean deviation (MD):1.21,95% confidence interval (CI): 0.26–2.16; p = 0.012], female gender [odds ratio (OR):1.12,95% CI: 1.00–1.26; p = 0.046], diabetes mellitus (DM) (OR:1.17,95% CI: 1.01–1.35; p = 0.032), occlusion of internal carotid artery (ICA) (OR:0.71,95% CI: 0.52–0.97; p = 0.033), occlusion of M2 segment of middle cerebral artery (OR:1.36,95% CI: 1.05–1.77; p = 0.019), duration of intervention (MD: −27.85, 95% CI: −42.11–13.58; p < 0.001), time of onset to recanalization (MD: −34.63, 95% CI: −58.45–10.81; p = 0.004), general anesthesia (OR: 0.63,95% CI: 0.52–0.77; p < 0.001), and use of balloon guide catheter (BGC) (OR:1.60,95% CI: 1.17–2.18; p = 0.003) were significantly associated with successful recanalization with FPE. At the same time, age, female gender, duration of intervention, general anesthesia, use of BGC, and occlusion of ICA were associated with complete reperfusion with FPE, but M2 occlusion and DM were not.

Conclusion: Age, gender, occlusion site, anesthesia type, and use of BGC were influencing factors for both successful and complete recanalization after first-pass thrombectomy. Further studies with more comprehensive observations indexes are need in the future.

Local anesthesia as a distinct comparator versus conscious sedation and general anesthesia in endovascular stroke treatment: a systematic review and meta-analysis

BACKGROUND

The optimal anesthetic modality for endovascular treatment (EVT) in acute ischemic stroke (AIS) is undetermined. Comparisons of general anesthesia (GA) with composite non-GA cohorts of conscious sedation (CS) and local anesthesia (LA) without sedation have provided conflicting results. There has been emerging interest in assessing whether LA alone may be associated with improved outcomes. We conducted a systematic review and meta-analysis to evaluate clinical and procedural outcomes comparing LA with CS and GA.

METHODS

We reviewed the literature for studies reporting outcome variables in LA versus CS and LA versus GA comparisons. The primary outcome was 90 day good functional outcome (modified Rankin Scale (mRS) score of ≤2). Secondary outcomes included mortality, symptomatic intracerebral hemorrhage, excellent functional outcome (mRS score ≤1), successful reperfusion (Thrombolysis in Cerebral Infarction (TICI) >2b), procedural time metrics, and procedural complications. Random effects meta-analysis was performed on unadjusted and adjusted data.

RESULTS

Eight non-randomized studies of 7797 patients (2797 LA, 2218 CS, and 2782 GA) were identified. In the LA versus GA comparison, no statistically significant differences were found in unadjusted analyses for 90 day good functional outcome or mortality (OR=1.22, 95% CI 0.84 to 1.76, p=0.3 and OR=0.83, 95% CI 0.64 to 1.07, p=0.15, respectively) or in the LA versus CS comparison (OR=1.14, 95% CI 0.76 to 1.71, p=0.53 and OR=0.88, 95% CI 0.62 to 1.24, p=0.47, respectively). There was a tendency towards achieving excellent functional outcome (mRS ≤1) in the LA group versus the GA group (OR=1.44, 95% CI 1.00 to 2.08, p=0.05, I²=70%). Analysis of adjusted data demonstrated a tendency towards higher odds of death at 90 days in the GA versus the LA group (OR=1.24, 95% CI 1.00 to 1.54, p=0.05, I²=0%).

CONCLUSION

LA without sedation was not significantly superior to CS or GA in improving outcomes when performing EVT for AIS. However, the quality of the included studies impaired interpretation, and inclusion of an LA arm in future well designed multicenter, randomized controlled trials is warranted.

A review of endovascular treatment for medium vessel occlusion stroke

Medium-vessel occlusions (MeVOs), that is, occlusions of the M2/3 middle cerebral artery, A2/3 anterior cerebral artery, and P2/3 posterior cerebral artery segments, account for 25%-40% of all acute ischemic stroke cases. Clinical outcomes of MeVO stroke with intravenous thrombolysis, which is the current standard of care, are moderate at best. With improving imaging technologies and a growing literature, MeVOs are increasingly recognized as a target for endovascular treatment (EVT). For the time being, there is limited but promising evidence for the safety and efficacy of MeVO EVT, and many neurointerventionists are already routinely offering EVT for MeVO stroke, despite the lack of clear guideline recommendations. In this article, we review the evidence on endovascular treatment for MeVO stroke and summarize the available literature on current imaging strategies, commonly used EVT selection criteria, EVT techniques, and outcome assessment for MeVO stroke.

Blood Pressure Thresholds and Neurologic Outcomes After Endovascular Therapy for Acute Ischemic Stroke: An Analysis of Individual Patient Data From 3 Randomized Clinical Trials

Importance

The optimal blood pressure targets during endovascular therapy (EVT) for acute ischemic stroke (AIS) are unknown.

Objective

To study whether procedural blood pressure parameters, including specific blood pressure thresholds, are associated with neurologic outcomes after EVT.

Design, Setting, and Participants

This retrospective cohort study included adults with anterior-circulation AIS who were enrolled in randomized clinical trials assessing anesthetic strategy for EVT between February 2014 and February 2017. The trials had comparable blood pressure protocols, and patients were followed up for 90 days. A total of 3630 patients were initially approached, and 3265 patients were excluded.

Exposure

Endovascular therapy.

Main Outcomes and Measures

The primary efficacy variable was functional outcome as defined by the modified Rankin Scale (mRS) score at 90 days. Associations of blood pressure parameters and time less than and greater than mean arterial blood pressure (MABP) thresholds with outcome were analyzed.

Results

Of the 365 patients included in the analysis, the mean (SD) age was 71.4 (13.0) years, 163 were women (44.6%), and the median National Institutes of Health Stroke Scale score was 17 (interquartile range [IQR], 14-21). For the entire cohort, 182 (49.9%) received general anesthesia and 183 (50.1%) received procedural sedation. A cumulated period of minimum 10 minutes with less than 70 mm Hg MABP (adjusted OR, 1.51; 95% CI, 1.02-2.22) and a continuous episode of minimum 20 minutes with less than 70 mm Hg MABP (adjusted OR, 2.30; 95% CI, 1.11-4.75) were associated with a shift toward higher 90-day mRS scores, corresponding to a number needed to harm of 10 and 4, respectively. A cumulated period of minimum 45 minutes with greater than 90 mm Hg MABP (adjusted OR, 1.49; 95% CI, 1.11-2.02) and a continuous episode of minimum 115 minutes with greater than 90 mm Hg MABP (adjusted OR, 1.89; 95% CI, 1.01-3.54) were associated with a shift toward higher 90-day mRS scores, corresponding to a number needed to harm of 10 and 6, respectively.

Conclusions and Relevance

Critical MABP thresholds and durations for poor outcome were found to be MABP less than 70 mm Hg for more than 10 minutes and MABP greater than 90 mm Hg for more than 45 minutes, both durations with a number needed to harm of 10 patients. Mean arterial blood pressure may be a modifiable therapeutic target to prevent or reduce poor functional outcome after EVT.

General Anesthesia versus Conscious Sedation in Mechanical Thrombectomy

Background and Purpose

Anesthesia regimen in patients undergoing mechanical thrombectomy (MT) is still an unresolved issue.

Methods

We compared the effect of anesthesia regimen using data from the German Stroke Registry-Endovascular Treatment (GSR-ET) between June 2015 and December 2019. Degree of disability was rated by the modified Rankin Scale (mRS), and good outcome was defined as mRS 0–2. Successful reperfusion was assumed when the modified thrombolysis in cerebral infarction scale was 2b–3.

Results

Out of 6,635 patients, 67.1% (n=4,453) patients underwent general anesthesia (GA), 24.9% (n=1,650) conscious sedation (CS), and 3.3% (n=219) conversion from CS to GA. Rate of successful reperfusion was similar across all three groups (83.0% vs. 84.2% vs. 82.6%, P=0.149). Compared to the CA-group, the GA-group had a delay from admission to groin (71.0 minutes vs. 61.0 minutes, P<0.001), but a comparable interval from groin to flow restoration (41.0 minutes vs. 39.0 minutes). The CS-group had the lowest rate of periprocedural complications (15.0% vs. 21.0% vs. 28.3%, P<0.001). The CS-group was more likely to have a good outcome at follow-up (42.1% vs. 34.2% vs. 33.5%, P<0.001) and a lower mortality rate (23.4% vs. 34.2% vs. 26.0%, P<0.001). In multivariable analysis, GA was associated with reduced achievement of good functional outcome (odds ratio [OR], 0.82; 95% confidence interval [CI], 0.71 to 0.94; P=0.004) and increased mortality (OR, 1.42; 95% CI, 1.23 to 1.64; P<0.001). Subgroup analysis for anterior circulation strokes (n=5,808) showed comparable results.

Conclusions

We provide further evidence that CS during MT has advantages over GA in terms of complications, time intervals, and functional outcome.

General anesthesia versus conscious sedation for endovascular therapy in acute ischemic stroke: A systematic review and meta-analysis

BACKGROUND

Endovascular thrombectomy (EVT) is the first-line treatment for patients with acute ischemic stroke (AIS). However, the optimal anesthetic modality during EVT is unclear. Therefore, this systematic review and meta-analysis is aimed to summarize the current literatures from RCTs to provide new clinical evidence of choosing anesthetic modality for AIS patients when receiving EVT.

METHODS

Literature search was conducted in following databases, EMBASE, MEDLINE, Web of Science, and the Cochrane Library, for relevant randomized controlled trials (RCTs) comparing general anesthesia (GA) and conscious sedation (CS) for AIS patients during EVT. We used the Cochrane Collaboration criteria for assessment of risk bias of included studies. The heterogeneity of outcomes was assessed by I²statistic.

RESULTS

5 RCTs with 498 patients were included. GA was conducted in 251 patients and CS in 247 patients. EVT under GA in AIS patients had higher rates of successful recanalization (RR: 1.13, 95% CI: 1.04-1.23; P = 0.004; I² = 40.6%) and functional independence at 3 months (RR: 1.28, 95% CI: 1.05-1.55; P = 0.013; I² = 18.2%) than CS. However, GA was associated with higher risk of mean arterial pressure (MAP) drop (RR: 1.71, 95% CI: 1.19-2.47; P < 0.01; I² = 80%) and pneumonia (RR: 2.32, 95% CI: 1.23-4.37; P = 0.009; I² = 33.5%). There was no difference between GA and CS groups in mortality at 3 months, interventional complications, intracerebral hemorrhage and cerebral infarction after 30 days.

CONCLUSIONS

GA was superior over CS in successful recanalization and functional independence at 3 months when performing EVT in AIS patients. However, GA was associated with higher risk of MAP drop and pneumonia. Therefore, results of ongoing RCTs will provide new clinical evidence of anesthetic modality selection during EVT in the future.

Acute ischemic stroke & emergency mechanical thrombectomy: The effect of type of anesthesia on early outcome

BACKGROUND

Endovascular mechanical thrombectomy (EMT) is the standard of care for acute ischemic stroke (AIS) caused by proximal large vessel occlusions. There is conflicting evidence on outcome of patients undergoing EMT under procedural sedation (PS) or general anesthesia (GA). In this retrospective study we analyze the effect of GA and PS on the functional outcome of patients undergoing EMT.

METHODS

Patients who have been admitted at our institute AIS and were treated with EMT under GA or PS between January 2015 and September 2018 were included in the study. Primary end point was the proportion of patients with good functional outcome as defined by a modified Rankin score (mRS) 0-2 at discharge.

RESULTS

A total of 155 patients were analyzed in this study including 45 (29.03 %) patients who received 97 GA, 110 (70.9 %) PS and 31 of these received Dexmedetomidine/Remifentanil. The median (IQR) 98 mRS at discharge was 4.0 (1.0-4.0) in the GA group Vs 3.00, (1.00-4.00) in the PS group. Among the secondary outcomes the lowest MAP recorded was significantly less in GA group (64.56 100 ± 18.70) compared to PS group (70.86 ± 16.30); p = 0.03. The PS group had a lower odd of mRS 3-5 (after adjustment), however, this finding was statistically not significant (OR 0.52 [0.07-3.5] 102 p = 0.5).

CONCLUSIONS

Our retrospective analysis did not find any influence of GA compared to PS whenever this was delivered by target controlled infusion (TCI) of propofol or by remifentanil/dexmedetomidine (REX) on early functional outcome.

Initial management of acute ischaemic stroke

The management of acute ischaemic stroke has been revolutionised by effective reperfusion therapies including thrombolysis and mechanical thrombectomy. In particular, mechanical thrombectomy has heralded a new era in stroke medicine. There have also been developments to improve clinical outcomes for patients who have had an acute ischaemic stroke but are not eligible for this procedure. This article presents an update on the initial management of acute ischaemic stroke, including reperfusion therapies, periprocedural considerations and ongoing research for potential improvements in the care of these patients.

Acute ischemic stroke endovascular therapy

Endovascular therapy (EVT) has become the standard treatment for large-vessel occlusion (LVO) acute ischemic stroke (AIS). EVT is now indicated in patients up to 24h from their last known well, provided that the patient meets specific clinical and imaging criteria. Improvements in thrombectomy devices, techniques, and operator experience have allowed successful EVT of ICA terminus, M1-MCA occlusions as well as proximal M2-MCA, basilar artery occlusions, and revascularization of tandem lesions. Mechanical thrombectomy failures still occur due to several factors, however, highlighting the need for further device and technical improvements. An ongoing debate exists regarding the need for pre-EVT thrombolytic agents, thrombectomy techniques, distal occlusions, anesthesia methods, the role of advanced neuroimaging, the treatment of patients with larger infarct core, and those presenting with milder stroke symptoms. Many of these questions are the subject of current or upcoming clinical trials. This review aims to provide an outline and discussion about the established recommendations and emerging topics regarding EVT for LVO AIS.

General Anesthesia Versus Conscious Sedation in Endovascular Thrombectomy for Stroke: A Meta-analysis of 4 Randomized Controlled Trials

BACKGROUND

In ischemic stroke patients, studies have suggested that clinical outcomes following endovascular thrombectomy are worse after general anesthesia (GA) compared with conscious sedation (CS). Most data are from observational trials, which are prone to measure and unmeasure confounding. We performed a systematic review and meta-analysis of thrombectomy trials where patients were randomized to GA or CS, and compared efficacy and safety outcomes.

METHODS

The Medline, Embase, and Cochrane databases were searched for randomized controlled trials comparing GA to CS in endovascular thrombectomy. Efficacy outcomes included successful recanalization (Thrombolysis in Cerebral Infarction score of 2b to 3), and good functional outcome, defined as a modified Rankin Scale score of 0 to 2 at 3 months. Safety outcomes included intracerebral hemorrhage and 3-month mortality.

RESULTS

Four studies were identified and included in the random effects meta-analysis. Patients treated with GA achieved a higher proportion of successful recanalization (odds ratio [OR]: 2.14, 95% confidence interval [CI]: 1.26-3.62; P=0.005) and good functional outcome (OR: 1.71, 95% CI: 1.13-2.59; P=0.01). For every 7.9 patients receiving GA, one more achieved good functional outcome compared with those receiving CS. There were no significant differences in intracerebral hemorrhage (OR: 0.61, 95% CI: 0.20-1.85; P=0.38) or 3-month mortality (OR: 0.62, 95% CI: 0.33-1.17; P=0.14) between GA and CS patients.

CONCLUSIONS

In centers with high quality, specialized neuroanesthesia care, GA treated thrombectomy patients had superior recanalization rates and better functional outcome at 3 months than patients receiving CS.

Patients Requiring Conversion to General Anesthesia during Endovascular Therapy Have Worse Outcomes: A Post Hoc Analysis of Data from the SAGA Collaboration

BACKGROUND AND PURPOSE

Endovascular therapy for acute ischemic stroke is often performed with the patient under conscious sedation. Emergent conversion from conscious sedation to general anesthesia is sometimes necessary. The aim of this study was to assess the functional outcome in converted patients compared with patients who remained in conscious sedation and to identify predictors associated with the risk of conversion.

MATERIALS AND METHODS

Data from 368 patients, included in 3 trials randomizing between conscious sedation and general anesthesia before endovascular therapy (SIESTA, ANSTROKE, and GOLIATH) constituted the study cohort. Twenty-one (11%) of 185 patients randomized to conscious sedation were emergently converted to general anesthesia.

RESULTS

Absence of hyperlipidemia seemed to be the strongest predictor of conversion to general anesthesia, albeit a weak predictor (area under curve = 0.62). Sex, hypertension, diabetes, smoking status, atrial fibrillation, blood pressure, size of the infarct, and level and side of the occlusion were not significantly associated with conversion to general anesthesia. Neither age (mean age, 71.3   ± 13.8 years for conscious sedation versus 71.6  ± 12.3 years for converters, P = .58) nor severity of stroke (mean NIHSS score, 17 ± 4 versus 18 ± 4, respectively, P = .27) were significantly different between converters and those who tolerated conscious sedation. The converters had significantly worse outcome with a common odds ratio of 2.67 (P = .015) for a shift toward a higher mRS score compared with the patients remaining in the conscious sedation group.

CONCLUSIONS

Patients undergoing conversion had significantly worse outcome compared with patients remaining in conscious sedation. No factor was identified that predicted conversion from conscious sedation to general anesthesia.

Endovascular treatment versus standard medical treatment for acute basilar artery occlusion: protocol for a systematic review and meta-analysis

INTRODUCTION

Acute basilar artery occlusion (BAO) can cause posterior circulation stroke. There are two predominant therapies for BAO: standard medical treatment (SMT) and SMT plus endovascular thrombectomy (EVT). However, a conclusive systematic comparison of the safety and efficacy of SMT and those of SMT plus EVT for the treatment of BAO is lacking. Thus, a systematic review and meta-analysis is needed to evaluate the safety and efficacy of SMT and SMT plus EVT for the treatment of BAO.

METHODS AND ANALYSIS

This protocol is drafted referring to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses for Protocols guidelines. We will search eligible studies from four main databases including MEDLINE, Web of Science, Cochrane Library and Embase. Randomised controlled trials (RCTs) and observational studies published before 1 October 2020 will be included. Two reviewers in our team will conduct the study selection and data extraction independently. Risk of bias will be assessed by Cochrane Collaboration criteria and the Newcastle-Ottawa scale for RCTs and observational studies, respectively. We will assess the good functional outcomes defining the modified Rankin scale score ≤2 at 90 days after treatment, short-term stroke severity as National Institutes of Health Stroke Scale score at 24 hours after intervention, and successful recanalisation as a modified Thrombolysis in Cerebral Infarction scale score of ≥2b after intervention. Also, safety outcomes will be assessed. The performance of this meta-analysis will depend on the quantity of included studies. The assessment of study heterogeneity will be performed by the I² statistic. If there is mild heterogeneity (I²<20%) of intervention outcomes in included studies, the fixed-effect model will be applied; otherwise, the random-effect model will be performed. Subgroup analyses and an assessment of publication bias will also be conducted with sufficient data.

ETHICS AND DISSEMINATION

No collection of primary data from patients is needed. Therefore, the ethical approval is unnecessary. The results may be presented in a peer-reviewed journal and related conferences.

PROSPERO REGISTRATION NUMBER

CRD42020176764.

Impact of Anesthetic Variation in Endovascular Treatment of Acute Ischemic Stroke

Background

Given recent technological advancements leading to better outcomes in endovascular therapy for acute ischemic stroke (AIS), updated guidelines recommend thrombectomy as the standard of care in acute large vessel occlusions. However, use of general anesthesia versus conscious sedation continues to be discussed. Two previous randomized trials have shown no significant difference between the use of conscious sedation compared with general anesthesia.

Methods

The authors performed a retrospective analysis of all consecutive patients with acute ischemia who underwent intra-arterial thrombectomy between September 2014 and May 2020 at a Level 1 stroke center. Patient characteristics along with clinical and operative data were extracted. Frequency distributions of selected characteristics were obtained and statistical significance of any differences according to the mode of anesthesia was assessed.

Results

A total of 480 patients were included in this study, 257 underwent general anesthesia and 223 underwent conscious sedation. Length of stay (LOS) in the ICU nor length of hospital stay was significantly different between groups. Change in National Institutes of Health Stroke Scale (NIHSS) score from admission to discharge, procedure times, and discharge disposition were not found to be significantly associated with either group although there was a trend towards longer door to puncture time with general anesthesia. Discharge disposition was found to be significantly associated with admission NIHSS (p=0.04). There was a trend towards longer hospital stay in patients with worse admission NIHSS (p=0.09). Success of thrombectomy was not significantly different between both anesthesia groups (p=0.37).

Conclusions

This large, single-center retrospective cohort study echoes the results of two previous randomized controlled trials in demonstrating non-inferiority of general anesthesia versus conscious sedation in cases of intra-arterial thrombectomy for AIS. These results contrast those of previously published retrospective studies.

Revascularization and functional outcomes after mechanical thrombectomy: an update to key metrics

OBJECTIVE

The advent of mechanical thrombectomy (MT) has become an effective option for the treatment of acute ischemic stroke in addition to tissue plasminogen activator (tPA). With recent advances in device technology, MT has significantly altered the hospital course and functional outcomes of stroke patients. The authors' goal was to establish the most up-to-date reperfusion and functional outcomes with the evolution of MT technology.

METHODS

The authors conducted a retrospective study of 403 patients who underwent MT for ischemic stroke at their institution from 2010 to 2017. They collected data on patient comorbidities, National Institutes of Health Stroke Scale (NIHSS) score on arrival, tPA administration, revascularization outcomes, and functional outcomes on discharge.

RESULTS

In 403 patients, the mean NIHSS score on presentation was 15.8 ± 6.6, with 195 (48.0%) of patients receiving tPA prior to MT. Successful reperfusion (thrombolysis in cerebral infarction score 2B or 3) was achieved in 84.4%. Hemorrhagic conversion with significant mass effect was noted in 9.9% of patients. The median lengths of ICU and hospital stay were 3.0 and 7.0 days, respectively. Functional independence (modified Rankin Scale score 0-2) was noted in 125 (31.0%) patients, while inpatient mortality occurred in 43 (10.7%) patients.

CONCLUSIONS

As MT has established acute ischemic stroke as a neurosurgical disease, there is a pressing need to understand the hospital course, hospital- and procedure-related complications, and outcomes for this new patient population. The authors provide a detailed account of key metrics for MT with the latest device technology and identify the predictors of unfavorable outcomes and inpatient mortality.