GASS Trial study protocol: a multicentre, single-blind, randomised clinical trial comparing general anaesthesia and sedation during intra-arterial treatment for stroke

Effect of Postoperative Prolonged sedation with Dexmedetomidine after successful reperfusion with Endovascular Thrombectomy on long-term prognosis in patients with acute ischemic stroke (PPDET): study protocol for a randomized controlled trial

BACKGROUND

Endovascular thrombectomy (EVT) is a standard treatment for acute ischemic stroke (AIS) with large vessel occlusion. Hypertension and increased blood pressure variability within the first 24 h after successful reperfusion are related to a higher risk of symptomatic intracerebral hemorrhage and higher mortality. AIS patients might suffer from ischemia-reperfusion injury following reperfusion, especially within 24 h. Dexmedetomidine (DEX), a sedative commonly used in EVT, can stabilize hemodynamics by inhibiting the sympathetic nervous system and alleviate ischemia-reperfusion injury through anti-inflammatory and antioxidative properties. Postoperative prolonged sedation for 24 h with DEX might be a potential pharmacological approach to improve long-term prognosis after EVT.

METHODS

This single-center, open-label, prospective, randomized controlled trial will include 368 patients. The ethics committee has approved the protocol. After successful reperfusion (modified thrombolysis in cerebral infarction scores 2b-3, indicating reperfusion of at least 50% of the affected vascular territory), participants are randomly assigned to the intervention or control group. In the intervention group, participants will receive 0.1~1.0 μg/kg/h DEX for 24 h. In the control group, participants will receive an equal dose of saline for 24 h. The primary outcome is the functional outcome at 90 days, measured with the categorical scale of the modified Rankin Scale, ranging from 0 (no symptoms) to 6 (death). The secondary outcome includes (1) the changes in stroke severity between admission and 24 h and 7 days after EVT, measured by the National Institute of Health Stroke Scale (ranging from 0 to 42, with higher scores indicating greater severity); (2) the changes in ischemic penumbra volume/infarct volume between admission and 7 days after EVT, measured by neuroimaging scan; (3) the length of ICU/hospital stay; and (4) adverse events and the all-cause mortality rate at 90 days.

DISCUSSION

This randomized clinical trial is expected to verify the hypothesis that postoperative prolonged sedation with DEX after successful reperfusion may promote the long-term prognosis of patients with AIS and may reduce the related socio-economic burden.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04916197. Prospectively registered on 7 June 2021.

Textural Analysis of the Hyperdense Artery Sign in Patients with Acute Ischemic Stroke Predicts the Outcome of Thrombectomy

Textural analysis is pivotal in augmenting the diagnosis and outcomes of endovascular procedures for stroke patients. Due to the detection of changes imperceptible to the human eye, this type of analysis can potentially aid in deciding the optimal type of endovascular treatment. We included 40 patients who suffered from acute ischemic stroke caused by large vessel occlusion, and calculated 130 different textural features based on the non-enhanced CT scan using an open-source software (3D Slicer). Using chi-squared and Mann-Whitney tests and receiver operating characteristics analysis, we identified a total of 21 different textural parameters capable of predicting the outcome of thrombectomy (quantified as the mTICI score), with variable sensitivity (50-97.9%) and specificity (64.6-99.4%) rates. In conclusion, CT-based radiomics features are potential factors that can predict the outcome of thrombectomy in patients suffering from acute ischemic stroke, aiding in the decision between aspiration, mechanical, or combined thrombectomy procedure.

Flawed, futile, and fabricated-features that limit confidence in clinical research in pain and anaesthesia: a narrative review

The randomised controlled trial is the foundation of clinical research; yet there is concern that many trials have flaws in design, conduct, and reporting that undermine trustworthiness. Common flaws in trials include high risk of bias, small size, outcomes irrelevant to clinical care and patient's experience, and inability to detect efficacy even if present. These flaws carry forward into systematic reviews, which can confer the label of 'high-quality evidence' on inadequate data. Trials can be futile because their flaws mean that they cannot deliver any meaningful result in that different results in a small number of patients would be sufficient to change conclusions. Some trials have been discovered to be fabricated, the number of which is growing. The fields of anaesthesia and pain have more fabricated trials than other clinical fields, possibly because of increased vigilance. This narrative review examines these themes in depth whilst acknowledging an inescapable conclusion: that much of our clinical evidence is in trouble, and special measures are needed to bolster quality and confidence.

Comparison of predictors of failure of early neurological improvement after successful endovascular treatment for posterior and anterior circulation large vessel occlusion: Data from ANGEL-ACT registry

PURPOSE

To identify and compare the predictors of failure of early neurological improvement (fENI)after successful EVT for anterior circulation large vessel occlusion (ACLVO) and posterior circulation LVO (PCLVO).

METHODS

Subjects were selected from the ANGEL-ACT registry. fENI was defined as unchanged or worsened in National Institutes of Health Stroke Scale score (NIHSS) between admission and 24 h after EVT. Predictors of fENI after successful EVT (mTICI 2b-3) were determined via center-adjusted analyses. Univariable and multivariable comparisons between ACLVO and PCLVO were performed.

RESULTS

A total of 1447 patients, 1128 were with ACLVO, and 319 were with PCLVO. Among the patients with ACLVO, there were 409 patients (36.3%) with fENI and 719 patients (63.7%) with ENI. We observed that pre-stroke mRS scale score of 2 (odd ratio[OR] 95% confidence interval[CI], 6.93[1.99-24.10], P = 0.002), initial NIHSS score (OR per point[95%CI], 0.97[0.95-0.99], P = 0.012), diabetes (OR[95%CI], 1.56[1.08-2.25], P = 0.017), previous ICH (OR[95%CI] 9.21[1.76-48.15], P = 0.008), local anesthesia (OR[95%CI] 1.63[1.10-2.42], P = 0.014), onset-to-puncture time (OR[95%CI], 1.001[1.000-1.001], P = 0.009), symptomatic ICH (OR[95%CI] 3.90[2.27-6.69], P < 0.001), and continued use of tirofiban within 2 h after EVT (OR[95%CI], 0.69[0.51-0.93], P = 0.014) were independent predictors of fENI of ACLVO after EVT. Among the patients with PCLVO, there were 112 patients (35.1%) with fENI and 207 patients (64.9%) with ENI. In contrast, admission SBP (OR[95%CI], 0.98[0.97-0.99], P = 0.012), and vascular dissection within 2 h after EVT (OR[95%CI], 7.23[1.33-39.13], P = 0.022) were independent predictors of fENI of PCLVO after EVT.

CONCLUSION

In selected patients, successful EVT can lead to similar outcomes in PCLVO and ACLVO. Some predictors of fENI in both anterior circulation and posterior circulation were identified in our study, which should be highly considered in the clinical practice in LVO patients undergoing EVT.

Ischemic Stroke, Lessons from the Past towards Effective Preclinical Models

Ischemic stroke is a leading cause of death worldwide, mainly in western countries. So far, approved therapies rely on reperfusion of the affected brain area, by intravenous thrombolysis or mechanical thrombectomy. The last approach constitutes a breakthrough in the field, by extending the therapeutic window to 16-24 h after stroke onset and reducing stroke mortality. The combination of pharmacological brain-protective strategies with reperfusion is the future of stroke therapy, aiming to reduce brain cell death and decrease patients' disabilities. Recently, a brain-protective drug-nerinetide-reduced brain infarct and stroke mortality, and improved patients' functional outcomes in clinical trials. The success of new therapies relies on bringing preclinical studies and clinical practice close together, by including a functional outcome assessment similar to clinical reality. In this review, we focused on recent upgrades of in vitro and in vivo stroke models for more accurate and effective evaluation of therapeutic strategies: from spheroids to organoids, in vitro models that include all brain cell types and allow high throughput drug screening, to advancements in in vivo preclinical mouse stroke models to mimic the clinical reality in surgical procedures, postsurgical care, and functional assessment.

Type of anaesthesia for acute ischaemic stroke endovascular treatment

BACKGROUND

The use of mechanical thrombectomy to restore intracranial blood flow after proximal large artery occlusion by a thrombus has increased over time and led to better outcomes than intravenous thrombolytic therapy alone. Currently, the type of anaesthetic technique during mechanical thrombectomy is under debate as having a relevant impact on neurological outcomes.

OBJECTIVES

To assess the effects of different types of anaesthesia for endovascular interventions in people with acute ischaemic stroke.

SEARCH METHODS

We searched the Cochrane Stroke Group Specialised Register of Trials on 5 July 2022, and CENTRAL, MEDLINE, and seven other databases on 21 March 2022. We performed searches of reference lists of included trials, grey literature sources, and other systematic reviews.  SELECTION CRITERIA: We included all randomised controlled trials with a parallel design that compared general anaesthesia versus local anaesthesia, conscious sedation anaesthesia, or monitored care anaesthesia for mechanical thrombectomy in acute ischaemic stroke. We also included studies reported as full-text, those published as abstract only, and unpublished data. We excluded quasi-randomised trials, studies without a comparator group, and studies with a retrospective design.

DATA COLLECTION AND ANALYSIS

Two review authors independently applied the inclusion criteria, extracted data, and assessed the risk of bias and the certainty of the evidence using the GRADE approach. The outcomes were assessed at different time periods, ranging from the onset of the stroke symptoms to 90 days after the start of the intervention. The main outcomes were functional outcome, neurological impairment, stroke-related mortality, all intracranial haemorrhage, target artery revascularisation status, time to revascularisation, adverse events, and quality of life. All included studies reported data for early (up to 30 days) and long-term (above 30 days) time points.

MAIN RESULTS

We included seven trials with 982 participants, which investigated the type of anaesthesia for endovascular treatment in large vessel occlusion in the intracranial circulation. The outcomes were assessed at different time periods, ranging from the onset of stroke symptoms to 90 days after the procedure. Therefore, all included studies reported data for early (up to 30 days) and long-term (above 30 up to 90 days) time points. General anaesthesia versus non-general anaesthesia(early) We are uncertain about the effect of general anaesthesia on functional outcomes compared to non-general anaesthesia (mean difference (MD) 0, 95% confidence interval (CI) -0.31 to 0.31; P = 1.0; 1 study, 90 participants; very low-certainty evidence) and in time to revascularisation from groin puncture until the arterial reperfusion (MD 2.91 minutes, 95% CI -5.11 to 10.92; P = 0.48; I² = 48%; 5 studies, 498 participants; very low-certainty evidence). General anaesthesia may lead to no difference in neurological impairment up to 48 hours after the procedure (MD -0.29, 95% CI -1.18 to 0.59; P = 0.52; I² = 0%; 7 studies, 982 participants; low-certainty evidence), and in stroke-related mortality (risk ratio (RR) 0.98, 95% CI 0.52 to 1.84; P = 0.94; I² = 0%; 3 studies, 330 participants; low-certainty evidence), all intracranial haemorrhages (RR 0.92, 95% CI 0.65 to 1.29; P = 0.63; I² = 0%; 5 studies, 693 participants; low-certainty evidence) compared to non-general anaesthesia. General anaesthesia may improve adverse events (haemodynamic instability) compared to non-general anaesthesia (RR 0.21, 95% CI 0.05 to 0.79; P = 0.02; I² = 71%; 2 studies, 229 participants; low-certainty evidence). General anaesthesia improves target artery revascularisation compared to non-general anaesthesia (RR 1.10, 95% CI 1.02 to 1.18; P = 0.02; I² = 29%; 7 studies, 982 participants; moderate-certainty evidence). There were no available data for quality of life. General anaesthesia versus non-general anaesthesia (long-term) There is no difference in general anaesthesia compared to non-general anaesthesia for dichotomous and continuous functional outcomes (dichotomous: RR 1.21, 95% CI 0.93 to 1.58; P = 0.16; I² = 29%; 4 studies, 625 participants; low-certainty evidence; continuous: MD -0.14, 95% CI -0.34 to 0.06; P = 0.17; I² = 0%; 7 studies, 978 participants; low-certainty evidence). General anaesthesia showed no changes in stroke-related mortality compared to non-general anaesthesia (RR 0.88, 95% CI 0.64 to 1.22; P = 0.44; I² = 12%; 6 studies, 843 participants; low-certainty evidence). There were no available data for neurological impairment, all intracranial haemorrhages, target artery revascularisation status, time to revascularisation from groin puncture until the arterial reperfusion, adverse events (haemodynamic instability), or quality of life. Ongoing studies We identified eight ongoing studies. Five studies compared general anaesthesia versus conscious sedation anaesthesia, one study compared general anaesthesia versus conscious sedation anaesthesia plus local anaesthesia, and two studies compared general anaesthesia versus local anaesthesia. Of these studies, seven plan to report data on functional outcomes using the modified Rankin Scale, five studies on neurological impairment, six studies on stroke-related mortality, two studies on all intracranial haemorrhage, five studies on target artery revascularisation status, four studies on time to revascularisation, and four studies on adverse events. One ongoing study plans to report data on quality of life. One study did not plan to report any outcome of interest for this review.

AUTHORS' CONCLUSIONS

In early outcomes, general anaesthesia improves target artery revascularisation compared to non-general anaesthesia with moderate-certainty evidence. General anaesthesia may improve adverse events (haemodynamic instability) compared to non-general anaesthesia with low-certainty evidence. We found no evidence of a difference in neurological impairment, stroke-related mortality, all intracranial haemorrhage and haemodynamic instability adverse events between groups with low-certainty evidence. We are uncertain whether general anaesthesia improves functional outcomes and time to revascularisation because the certainty of the evidence is very low. However, regarding long-term outcomes, general anaesthesia makes no difference to functional outcomes compared to non-general anaesthesia with low-certainty evidence. General anaesthesia did not change stroke-related mortality when compared to non-general anaesthesia with low-certainty evidence. There were no reported data for other outcomes. In view of the limited evidence of effect, more randomised controlled trials with a large number of participants and good protocol design with a low risk of bias should be performed to reduce our uncertainty and to aid decision-making in the choice of anaesthesia.

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

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.