ESJ Featured Article of the Month – September 2026: Anaesthesia during medium and distal vessel thrombectomy: a signal, not yet a strategy

Endovascular treatment (EVT) has transformed large-vessel occlusion stroke care, and it is now standard of care, but its role in medium or distal vessel occlusion (MDVO) remains uncertain. DISTAL and ESCAPE-MeVO were neutral, while a more recent trial suggested benefit in selected patients with greater clinical severity. [2-4] When the expected treatment effect is modest, procedural details may determine whether efficacy is preserved or lost. In their new European Stroke Journal paper, Räty and colleagues ask an important question: could anaesthesia modality explain the neutral result of DISTAL? [1]

This post-hoc, as-treated analysis included 491 of the 543 patients randomised across 55 centres in 11 countries. Of these, 267 received best medical treatment (BMT) alone, and 224 underwent EVT plus BMT: 108 under general anaesthesia (GA), 64 under local anaesthesia (LA), and 52 under conscious sedation (CS). No anaesthesia subgroup showed superiority of EVT over BMT. However, EVT under CS was associated with a worse 90-day modified Rankin Scale shift than BMT alone (adjusted common odds ratio 0.51, 95% CI 0.29-0.90). Within the EVT cohort, LA was associated with better functional outcome than CS (aOR 2.11, 95% CI 1.09-4.12) and lower mortality (aOR 0.28, 95% CI 0.08-0.95).

Reperfusion rates were similar across modalities – 78.1% with GA, 82.8% with LA, and 78.0% with CS – indicating that patient movement under less intensive anaesthesia did not meaningfully reduce angiographic success. A safety signal nevertheless deserves attention: symptomatic intracranial haemorrhage occurred in 8.3% of the GA group versus 2.6% with BMT (aOR 3.37, 95% CI 1.22-9.66), and all six vessel perforations occurred under GA.

At first glance, LA appears preferable, but that conclusion is premature. Anaesthesia was selected by treating teams according to local practice rather than randomly assigned. The choice may reflect case complexity. GA may have been preferred for agitation, tortuous anatomy, distal targets, or technically demanding procedures, whereas patients managed with LA may have had more favourable clinical profiles. The CS cohort was small and slightly older, and 52 patients were excluded, including conversions to GA and cases in which EVT was not performed.

The exposure itself was also incompletely characterised. The study did not record the initially intended modality, sedative agents and doses, depth of sedation, airway strategy, intraprocedural blood pressure, oxygenation, carbon dioxide, patient movement, or reasons for conversion. Because “conscious sedation” may encompass markedly different physiological states across centres, the exposure is difficult to interpret consistently. The analysis also involved unadjusted multiple comparisons, wide subgroup confidence intervals, and insufficient power for head-to-head comparisons or a formal treatment-by-anaesthesia interaction. These limitations make the observed associations vulnerable to confounding by indication and preclude causal interpretation.

The study also has important strengths. It draws on a large international randomised trial, uses blinded 90-day outcome assessment and core-laboratory imaging evaluation, accounts for centre clustering in the ordinal analysis, and includes several sensitivity analyses. Crucially, it treats LA and CS as distinct strategies rather than combining them into a heterogeneous “non-GA” category – a distinction increasingly supported by the literature. [5-8]

What does this mean for clinical practice? The findings neither support routine LA nor demonstrate that GA is harmful. Instead, they favour an individualised, protocol-based approach using the least intensive modality that still maintains immobility, airway safety, and haemodynamic stability. Most importantly, anaesthesia choice does not explain the overall lack of EVT benefit in DISTAL.

Future MDVO trials should prespecify or randomise anaesthesia strategies and use standardised definitions. Time-resolved physiological data, medication doses, movement, conversions, target anatomy, and procedural difficulty should all be captured. This would help determine whether anaesthesia is a causal modifier, a mediator, or simply a marker of a difficult case. For now, this thoughtful analysis generates valuable hypotheses – but not a new anaesthesia mandate.

References

1. Räty S, Strbian D, Mannismäki L, et al. Effect of anaesthesia modality on outcome in medium or distal vessel occlusion stroke: a post-hoc analysis of the DISTAL trial. Eur Stroke J. 2026;11(8):aakag088. doi:10.1093/esj/aakag088
2. Psychogios M, Brehm A, Ribo M, et al. Endovascular treatment for stroke due to occlusion of medium or distal vessels. N Engl J Med. 2025;392:1374-1384. doi:10.1056/NEJMoa2408954
3. Goyal M, Ospel JM, Ganesh A, et al. Endovascular treatment of stroke due to medium-vessel occlusion. N Engl J Med. 2025;392:1385-1395. doi:10.1056/NEJMoa2411668
4. Hu W, Jing X, Chen Z, et al. Endovascular treatment of medium-vessel-occlusion strokes. N Engl J Med. 2026;394:1894-1904. doi:10.1056/NEJMoa2514120
5. Kappelhof M, Ospel JM, Cimflova P, et al. Worldwide anaesthesia use during endovascular treatment for medium vessel occlusion stroke. Interv Neuroradiol. 2022;28:469-475. doi:10.1177/15910199211041487
6. Butt W, Dhillon PS, Podlasek A, et al. Local anesthesia as a distinct comparator versus conscious sedation and general anesthesia in endovascular stroke treatment: a systematic review and meta-analysis. J Neurointerv Surg. 2022;14:221-226. doi:10.1136/neurintsurg-2021-017360
7. Doheim MF, Knapen RR, Dippel DW, et al. Association of anesthesia strategies with outcomes in endovascular treatment for distal and medium vessel occlusions: a propensity score-matched analysis of the MR CLEAN Registry and meta-analysis. Eur Stroke J. 2026;11:23969873251352406. doi:10.1093/esj/23969873251352406
8. Radu RA, Costalat V, Romoli M, et al. Outcomes with general anesthesia compared to conscious sedation for endovascular treatment of medium vessel occlusions. Clin Neuroradiol. 2024;34:761-769. doi:10.1007/s00062-024-01415-1