Acute Ischemic Stroke Large-Vessel Occlusion: Vascular-Surgery Interface

33.1Definition and presentation

Acute ischemic stroke with large-vessel occlusion (LVO) is a time-sensitive neurological emergency managed primarily by acute stroke teams. The vascular surgery interface occurs when extracranial arterial anatomy alters the ability to reach or maintain intracranial reperfusion, or when subsequent carotid revascularization is required AHA/ASA 2019 · AHA/ASA 2018.

Presentation to vascular surgery follows specific anatomic or technical triggers during the acute stroke pathway:

• Tandem cervical carotid occlusion or critical stenosis obstructing inflow.
• Anticipated or encountered hostile aortic arch anatomy.
• Severe ilio-femoral tortuosity or occlusive disease preventing transfemoral catheter progress.
• Requirement for early planning of post-reperfusion carotid revascularization and antithrombotic management ESVS 2023.

33.2Diagnosis and imaging stratification

Imaging dictates the boundary of intervention by defining established infarct extent and salvageable tissue. The Alberta Stroke Program Early CT Score (ASPECTS) quantifies early ischemic change on non-contrast CT across ten regions, with lower scores reflecting larger established infarcts ASPECTS · 2000.

Perfusion imaging identifies patients in later windows by demonstrating a mismatch between clinical deficit and infarct core, or a volumetric mismatch between salvageable penumbra and completed core DAWN · 2018 · DEFUSE-3 (2018). Angiographic reperfusion is graded post-procedure by the modified Thrombolysis in Cerebral Infarction (mTICI) scale to document recanalization success, but it does not establish pre-procedural eligibility TICI (2013). Decisions regarding access rescue and tandem carotid intervention rely on confirming a tissue profile that supports functional recovery rather than reperfusion of a completed infarct.

33.3Thrombectomy evidence and eligibility

Endovascular thrombectomy eligibility is stratified by time window, anatomy, and infarct volume. The primary evidence base for anterior-circulation LVO establishes benefit for mechanical thrombectomy plus best medical therapy over medical therapy alone, primarily within 6 hours of symptom onset HERMES · 2016 · ESCAPE · 2015 · EXTEND-IA (2015) · MR CLEAN (2015) · REVASCAT · 2015 · SWIFT PRIME (2015). The magnitude anchors the whole pathway: the pooled patient-level meta-analysis found an adjusted common odds ratio of 2.49 (95% CI 1.76 to 3.53) for reduced disability across the modified Rankin scale at 90 days, with functional independence (mRS 0 to 2) in 46.0% versus 26.5% and a number needed to treat of roughly 2.6 to reduce disability by at least one level.

Late-window intervention is supported for patients 6 to 24 hours from last known well who demonstrate a clinical-imaging mismatch, and for patients 6 to 16 hours from last known well with a defined perfusion-core mismatch DAWN · 2018 · DEFUSE-3 (2018). These windows are perfusion-gated, not clock-gated. DEFUSE-3 (6 to 16 h) required an ischemic core below 70 mL, a mismatch ratio of at least 1.8, and an absolute penumbra of at least 15 mL. DAWN (6 to 24 h) tied the tolerable core to age and deficit: core below 21 mL for age 80 or older with NIHSS 10 or higher; core below 31 mL for age under 80 with NIHSS 10 or higher; and core of 31 to below 51 mL for age under 80 with NIHSS 20 or higher.

Expanded eligibility into large-core or low-ASPECTS anterior-circulation strokes demonstrates a smaller absolute disability benefit alongside increased symptomatic intracerebral hemorrhage risk ANGEL-ASPECT · 2023 · SELECT2 · 2023 · RESCUE-Japan LIMIT (2022). The numeric boundary matters at the console. Standard early-window thrombectomy was established for ASPECTS 6 or higher AHA/ASA 2019; the large-core trials pushed below it. SELECT2 enrolled ASPECTS 3 to 5 or a core of 50 mL or more, ANGEL-ASPECT enrolled ASPECTS 3 to 5 or a core of 70 to 100 mL, and RESCUE-Japan LIMIT enrolled ASPECTS 3 to 5. Basilar-artery occlusion has a distinct natural history; while selected populations show functional benefit from thrombectomy, the therapeutic margin differs from anterior-circulation LVO ATTENTION · 2022 · BASICS · 2021.

33.4Management of tandem disease and access

Tandem cervical carotid disease functions simultaneously as the embolic source, the inflow obstruction, and the mechanical barrier to intracranial thrombectomy. Management requires balancing the technical need for a stable conduit against the bleeding risk of acute antithrombotic therapy in newly reperfused, infarcted brain tissue. Acute carotid stenting (ACS) secures inflow but necessitates immediate dual antiplatelet therapy. Staged carotid endarterectomy (CEA) or stenting (CAS) preserves antithrombotic flexibility during the acute phase but accepts an interval risk of recurrent embolization or re-occlusion ESVS 2023.

Where transfemoral access fails due to severe ilio-femoral disease or a hostile arch, access rescue is established via common-carotid cutdown or percutaneous direct carotid puncture to maintain the stroke treatment window ESVS 2023 · AHA/ASA 2019.

The interventional decision follows a stepwise sequence:

1. Verify thrombectomy eligibility based on established stroke-team imaging and time criteria.
2. Determine if transfemoral access is viable or if common-carotid access rescue is immediately required.
3. Evaluate tandem cervical carotid lesions for their impact on intracranial device delivery.
4. Proceed with acute carotid stenting if required to reach the intracranial target, accepting the requirement for early dual antiplatelet therapy.
5. Defer to staged CEA or CAS if the intracranial occlusion can be treated without stabilizing the neck lesion, particularly when early hemorrhagic risk prohibits intense antithrombotic therapy.
6. Align post-operative carotid surveillance and antithrombotic de-escalation with the acute neurological assessment.

33.5Areas of controversy

The optimal timing of intervention for tandem cervical carotid lesions remains unsettled. Acute carotid stenting at the time of thrombectomy and delayed CEA or CAS are managed as observational options, lacking randomized head-to-head comparison in the acute stroke setting ESVS 2023.

The application of acute carotid stenting in patients with a large infarct core is particularly contested, as the mandatory dual antiplatelet therapy amplifies an already elevated symptomatic intracerebral hemorrhage risk ANGEL-ASPECT · 2023 · SELECT2 · 2023 · RESCUE-Japan LIMIT (2022).

Extrapolation of anterior-circulation thrombectomy rules to basilar-artery occlusion remains challenging due to divergent primary endpoints between selected-population trials and broader procedural cohorts ATTENTION · 2022 · BASICS · 2021.