Endovascular Thrombectomy & Large Vessel Occlusion

Recognize the Treatable Occlusion

Endovascular thrombectomy (EVT) mechanically removes thrombus from an accessible occluded artery using aspiration, a stent retriever, or selected combined techniques. The first decision is whether the clinical syndrome and vascular imaging indicate an occlusion for which treatment offers benefit. NIHSS, prestroke function, time, vessel location, tissue injury, collateral supply, and procedural feasibility all contribute. Do not equate every angiographic occlusion with identical eligibility.

Obtain rapid brain and vascular imaging and arrange neurointerventional assessment without unnecessary delay. Eligible IV thrombolysis should not be postponed merely to see whether EVT will occur or whether the patient improves. Conversely, being outside a conventional thrombolysis window does not by itself exclude EVT. Systems of care, transfer, and avoiding treatment delays remain important even when tissue imaging suggests salvageable brain.

Early and Extended Windows

The 2015 trials and HERMES patient-level meta-analysis established substantial disability reduction for selected proximal anterior-circulation occlusions. HERMES' reported number needed to treat of 2.6 concerned improvement by at least one modified Rankin Scale level. It should not be relabeled as the number needed for functional independence, which is a different endpoint.

DAWN studied selected patients 6–24 hours after last known well using a clinical-core mismatch. DEFUSE-3 studied selected patients 6–16 hours using a perfusion mismatch, with core below 70 mL, mismatch ratio at least 1.8, and mismatch volume at least 15 mL. These are historic trial-selection rules, not evidence that every patient who falls outside them must be denied treatment under current guidance.

For example, a core of 28 mL and hypoperfused volume of 105 mL give a ratio of 105/28 = 3.75 and mismatch volume 105−28 = 77 mL. Those values satisfy the DEFUSE-3 imaging mismatch thresholds, but vessel, time, clinical, and other eligibility requirements must still be assessed. A calculator result cannot replace interpretation of the source scans and vascular anatomy.

Large-Core and Basilar Occlusion

Randomized trials including SELECT2, ANGEL-ASPECT, RESCUE-Japan LIMIT, and other studies expanded evidence for selected large-core anterior-circulation strokes. Benefit is usually expressed as improved disability outcomes, not a guarantee of independence or normal recovery. Trials differ in ASPECTS, core volume, time, and inclusion criteria. TESLA did not meet its prespecified primary superiority threshold, so it should not be listed as an identically positive trial.

The 2026 guideline incorporates expanded EVT recommendations for selected large cores. Interpret ASPECTS with the full clinical and imaging context. A low score is no longer a universal exclusion, while extensive injury and other adverse features still matter. Automated perfusion estimates can overestimate or underestimate injury; a colored map does not prove histologically irreversible tissue in every voxel.

For basilar artery occlusion, ATTENTION and BAOCHE support treatment in selected patients. The 2026 guideline provides a strong recommendation for appropriate patients presenting within 24 hours with NIHSS at least 10. Posterior-circulation deficits may be inadequately represented by a low NIHSS, so urgent expert assessment remains necessary rather than relying on the score alone.

Reperfusion Grading and Anesthesia

Subdivisions and expanded grading systems add detail, so use the procedural report's definition. Reperfusion is an angiographic result; clinical recovery also depends on tissue injury, time, collaterals, and complications. A technically excellent result does not exclude infarction, hemorrhage, or later edema.

General anesthesia and procedural sedation are selected according to airway protection, cooperation, oxygenation, hemodynamics, and local expertise. Neither technique is universally superior for every patient. Prevent hypoxemia and avoid significant procedural hypotension, especially while tissue remains collateral-dependent. A controlled airway can help in an uncooperative or obtunded patient, but induction and transfer can also delay treatment or lower pressure if poorly coordinated.

Post-EVT Blood Pressure and Surveillance

The 2026 AHA/ASA guideline advises against intensive SBP lowering below 140 mm Hg after EVT, even with complete reperfusion. Trials of intensive lowering did not establish the benefit claimed in older physiologic arguments and identified harm in relevant settings. Do not use mTICI 3 as an automatic instruction to target SBP 120–130 or strictly below 140.

A usual upper limit around 180/105 mm Hg is used during and after EVT under the guideline, with individualized management of other emergencies, hypotension, and procedural circumstances. Maintain stable perfusion rather than selecting an arbitrary narrow target from an angiographic grade alone. Follow neurologic status, access-site complications, glucose, temperature, and appropriate imaging. New deficits warrant prompt assessment for hemorrhage, reocclusion, edema, seizures, or systemic deterioration.

Sources checked October 17, 2026: 2026 AHA/ASA summary, HERMES, and TESLA.