Type of anaesthesia for acute ischaemic stroke endovascular treatment

The effect of inadvertent systemic hypothermia after mechanical thrombectomy in patients with large-vessel occlusion stroke

Background and aims

Postinterventional hypothermia is a frequent complication in patients with large-vessel occlusion strokes (LVOS) after mechanical thrombectomy (MT). This inadvertent hypothermia might potentially have neuroprotective but also adverse effects on patients' outcomes. The aim of the study was to determine the rate of hypothermia in patients with LVOS receiving MT and its influence on functional outcome.

Methods

We performed a monocentric, retrospective study using a prospectively derived databank, including all LVOS patients receiving MT between 2015 and 2021. Predictive values of postinterventional body temperature and body temperature categories (hyperthermia (≥38°C), normothermia (35°C-37.9°C), and hypothermia (<35°C)) on functional outcome were analyzed using multivariable Bayesian logistic regression models. Favorable outcome was defined as modified Rankin Scale (mRS) ≤3.

Results

Of the 480 included LVOS patients with MT (46.0% men; mean ± SD age 73 ± 12.9 years), 5 (1.0%) were hyperthermic, 382 (79.6%) normothermic, and 93 (19.4%) hypothermic. Postinterventional hypothermia was significantly associated with unfavorable functional outcome (mRS > 3) after 90 days (OR 2.06, 95% CI 1.01-4.18, p = 0.045). For short-term functional outcome, patients with hypothermia had a higher discharge NIHSS (OR 1.38, 95% CI 1.06 to 1.79, p = 0.015) and a higher change of NIHSS from admission to discharge (OR 1.35, 95% CI 1.03 to 1.76, p = 0.029).

Conclusion

Approximately a fifth of LVOS patients in this cohort were hypothermic after MT. Hypothermia was an independent predictor of unfavorable functional outcomes. Our findings warrant a prospective trial investigating active warming during MT.

General anesthesia or conscious sedation for thrombectomy in stroke patients: an updated systematic review and meta-analysis

PURPOSE

Endovascular treatment for stroke patients usually requires anesthesia care, with no current consensus on the best anesthetic management strategy. Several randomized controlled trials and meta-analyses have attempted to address this. In 2022, additional evidence from three new trials was published: the GASS trial, the CANVAS II trial, and preliminary results from the AMETIS trial, prompting the execution of this updated systematic review and meta-analysis. The primary objective of this study was to evaluate the effects of general anesthesia and conscious sedation on functional outcomes measured with the modified Rankin scale (mRS) at three months.

METHODS

We performed a systematic review and meta-analysis of randomized controlled trials investigating conscious sedation and general anesthesia in endovascular treatment. The following databases were examined: PubMed, Scopus, Embase, and the Cochrane Database of Randomized Controlled Trials and Systematic Reviews. The Risk of Bias 2 tool was used to assess bias. In addition, trial sequence analysis was performed on the primary outcome to estimate if the cumulative effect is significant enough to be unaffected by further studies.

RESULTS

Nine randomized controlled trials were identified, including 1,342 patients undergoing endovascular treatment for stroke. No significant differences were detected between general anesthesia and conscious sedation with regards to mRS, functional independence (mRS, 0-2), procedure duration, onset to reperfusion, mortality, hospital length of stay, and intensive care unit length of stay. Patients treated under general anesthesia may have more frequent successful reperfusion, though the time from groin to reperfusion was slightly longer. Trial sequential analysis showed that additional trials are unlikely to show marked differences in mean mRS at three months.

CONCLUSIONS

In this updated systematic review and meta-analysis, the choice of anesthetic strategy for endovascular treatment of stroke patients did not significantly impact functional outcome as measured with the mRS at three months. Patients managed with general anesthesia may have more frequent successful reperfusion.

TRIAL REGISTRATION

PROSPERO (CRD42022319368); registered 19 April 2022.

General anesthesia but not conscious sedation improves functional outcome in patients receiving endovascular thrombectomy for acute ischemic stroke: A meta-analysis of randomized clinical trials and trial sequence analysis

Background

This study aimed at comparing the difference in prognostic outcomes between patients receiving general anesthesia (GA) and conscious sedation (CS) for endovascular thrombectomy after acute ischemic stroke.

Methods

Databases from Medline, Embase, Google scholar, and Cochrane library were searched for randomized controlled studies (RCTs) comparing patients undergoing GA and CS for endovascular thrombectomy following anterior circulation ischemic stroke. The primary outcome was frequency of 90-day good functional outcome [defined as modified Rankin Scale score of ≤ 2], while secondary outcomes included successful recanalization rate (SRR) [i.e., modified thrombolysis in cerebral infarction = 2b or 3], mortality risk, symptomatic intracranial hemorrhage (ICH), procedure-related complications, hypotension, pneumonia, neurological outcome at post-procedure 24–48 h, and puncture-to-recanalization time.

Results

Six RCTs including 883 patients published between 2016 and 2022 were included. Merged results revealed a higher SRR [risk ratio (RR) = 1.11, 95% CI: 1.03–1.2, p = 0.007; I² = 29%] and favorable neurological outcomes at 3-months (RR = 1.2, 95% CI: 1.01–1.41, p = 0.04; I² = 8%) in the GA group compared to CS group, without difference in the risk of mortality (RR = 0.88), symptomatic ICH (RR = 0.91), procedure-related complications (RR = 1.05), and pneumonia (RR = 1.9) as well as post-procedure neurological outcome (MD = −0.21) and successful recanalization time (MD = 3.33 min). However, GA was associated with a higher risk of hypotension compared with that of CS.

Conclusion

Patients with acute anterior circulation ischemic stroke receiving GA were associated with a higher successful recanalization rate as well as a better 3-month neurological outcome compared to the use of CS. Further investigations are warranted to verify our findings.

Systematic review registration

www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022342483, identifier: CRD42022342483.

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.