Melanie R. F. Greenway, MD
As mechanical reperfusion therapy continues to advance, questions regarding procedural methods of anesthesia continue to arise. This article compares functional outcomes in patients who received local anesthesia or conscious sedation for mechanical thrombectomy in acute ischemic stroke.
Utilizing the Endovascular Treatment in Ischemic Stroke Registry (ETIS) in France, the authors evaluated 1034 patients with large vessel occlusion admitted for mechanical thrombectomy from January to December 2018 at 4 centers. Three centers used a protocol with conscious sedation as the first-line treatment approach for mechanical thrombectomy, while one center used local anesthesia as the first-line treatment approach. After excluding patients because of missing information, absence of large vessel occlusion, or other exclusion criteria, 636 patients from the conscious sedation centers and 238 from the local anesthesia center were included in the intention-to-treat analysis. From there, 577 patients in the conscious sedation group and 185 patients from the local anesthesia group were included in the per-protocol analysis, as additional patients were excluded because of a change to their anesthesia management after enrollment.
A propensity-score matched cohort demonstrated a favorable outcome (mRS 0-2 at 90 days) in the conscious sedation group of 52% compared with 40% in the local anesthesia group. Additionally, the rate of favorable reperfusion (TICI 2b-3) was 87.1% in the conscious sedation group and 76.6% in the local anesthesia group. Similar findings were seen with subsequent inverse probability of treatment weighting (IPTW) analysis. The Figure below provides a summary of the outcomes.
Interestingly, the procedure time did not vary between conscious sedation and local anesthesia groups, when reperfusion was successful. Procedural complications were not significantly different between the two groups.
The study design compared three centers that use conscious sedation as their first-line treatment method to one center that uses local anesthesia as their first-line treatment method. While this approach relied on the peri-procedural methods that each center uses most frequently and comfortably, it could introduce the potential bias that the treatment differences seen are related to other differences among centers.
A recent meta-analysis of three randomized clinical trials (SIESTA [Sedation vs Intubation for Endovascular Stroke Treatment], ANSTROKE [Anesthesia During Stroke], and GOLIATH [General or Local Anesthesia in Intra Arterial Therapy]) demonstrated general anesthesia compared with conscious sedation was associated with less disability at three months.1 This is in contrast to the HERMES collaboration, which demonstrated a better functional outcome (mRS 0-2) at three months with conscious sedation (50%) compared with general anesthesia (40%).2
While general anesthesia was not used in the current study, it is important to recognize the clinical controversy that exists among all peri-procedural methods for mechanical thrombectomy. Reasons for conflicting results include patient differences (initial NIHSS, vessel occlusion involved, co-morbid conditions, time to presentation, etc.), peri-procedural management such as blood pressure, and study limitations, as it relates to confounding variables.
To complicate the matter of procedural anesthesia, the COVID-19 pandemic has forced providers to re-evaluate hospital protocols as the pandemic spreads around the world. The Society for Neuroscience in Anesthesiology and Critical Care consensus statement recommends a lower threshold for general anesthesia in patients who are unable to provide history of COVID-19–related symptoms (such as those patients who are aphasic) or unable to receive rapid COVID-19 testing prior to mechanical reperfusion.3
Moving forward, continued research into appropriate anesthetic selection will require collaboration among vascular neurologists, neurointerventionalists, and anesthesiologists. As with the decision to pursue mechanical revascularization, the decision to pursue a particular type of anesthesia will likely require detailed patient selection taking many factors into consideration, including time since last known well, initial NIHSS, vessel involved, and co-morbid conditions, including COVID-19 status.
References:
- Schönenberger S, Henden P, Simonsen C, Uhlmann L, Klose C, Pfaff J, Yoo A, Sørensen L, Ringleb P, Wick W, et al. Association of General Anesthesia vs Procedural Sedation with Fuctional Outcome Among Patients with Acute Ischemic Stroke Undergoing Mechanical Thrombectomy: A Systematic Review and Meta-analysis. JAMA. 2019; 322: 1283-1293.
- Campbell B, van Zwam W, Goyal M, Menon B, Dippel D, Demchuk A, Bracard S, White P, Dávalos A, Majoie C, et al. 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. Lancet. 2018; 17:47-53.
- Sharma D, Rasmussen M, Han R, Whalin M, Davis M, Kofke W, Venkatraghvan L, Raychev R, Fraser J. Anesthetic Management of Endovascular Treatment of Acute Ischemic Stroke During COVID-19 Pandemic: Consensus Statement From Society for Neuroscience in Anesthesiology and Critical Care (SNACC). Journal of Neurosurgical Anesthesiology. 2020; 32: 193-201.
