What is the role of rescue stenting in patients with acute ischemic stroke who have failed initial thrombolytic therapy?

Rescue Stenting for Acute Ischemic Stroke

Rescue stenting should be performed when mechanical thrombectomy fails to achieve adequate recanalization (TICI <2b) after multiple passes, particularly in patients with underlying intracranial atherosclerotic disease (ICAD) causing the occlusion. 1

Primary Recommendation

For patients with failed endovascular thrombectomy, rescue percutaneous transluminal angioplasty (PTA) and/or stenting is recommended as a bailout strategy to achieve TICI 2b/3 recanalization. 1 The 2015 AHA/ASA guidelines explicitly state that salvage technical adjuncts, including rescue stenting, may be reasonable to achieve TICI grade 2b/3 angiographic results if completed within 6 hours of symptom onset (Class IIb; Level of Evidence B-R). 1

When to Deploy Rescue Stenting

Specific Indications:

• Failed mechanical thrombectomy after at least 3 passes with persistent occlusion (TICI 0-2a) 2
• Severe underlying stenosis (≥70%) identified at the occlusion site after thrombectomy attempts 1, 3
• Reocclusion or flow insufficiency despite initial partial recanalization 4
• Intracranial atherosclerotic disease (ICAD) as the underlying cause of large vessel occlusion 1, 3

Expert Consensus Position:

The 2024 ESO/ESMINT guidelines on basilar artery occlusion provide an expert consensus (10/10 members) suggesting rescue PTA and/or stenting after failed endovascular procedures in patients with suspected ICAD and severe underlying stenosis. 1 While this specifically addresses basilar artery occlusion, the principle extends to anterior circulation ICAD-related occlusions. 1

Evidence Supporting Rescue Stenting

Efficacy Data:

• Recanalization rates: 79-96.5% successful recanalization achieved with rescue stenting 5, 6
• Functional outcomes: 51.6% good functional outcome (mRS 0-2) at 90 days with rescue stenting versus 35.0% without (adjusted OR: 2.11,95% CI: 1.22-4.29) 3
• Mortality benefit: 15.2% mortality with rescue stenting versus 35.1% without (p=0.03) 2
• Reocclusion prevention: Lower 24-hour reocclusion rate (6.3% vs. 17.5%, p=0.03) 3

Safety Profile:

• Symptomatic intracranial hemorrhage: 4.7-7.8% rate, comparable to thrombectomy alone 3, 5
• No significant increase in procedural complications compared to failed thrombectomy without rescue intervention 2

Technical Considerations

Timing:

• Must be completed within 6 hours of symptom onset to align with guideline recommendations 1
• Average time-to-treatment in successful series: 210 ± 160 minutes from onset 6

Antiplatelet Management:

The 2024 ESO/ESMINT guidelines suggest add-on antithrombotic treatment during or within 24 hours after EVT as a rescue strategy for complicated procedures, after assessing bleeding risk. 1 However, dual antiplatelet therapy (DAPT) requires careful consideration:

• DAPT associated with reduced new infarcts (RR=0.1) and symptomatic ICH (RR=0.1) in some series 5
• Intra-arterial tirofiban infusion appears effective as rescue treatment 4
• Balance hemorrhage risk against reocclusion prevention 1

Cervical Carotid Considerations:

For tandem occlusions with proximal cervical carotid stenosis or occlusion (present in 18.6-32.2% of thrombectomy cases), the optimal management remains uncertain. 1 The 2015 AHA/ASA guidelines state that angioplasty and stenting of proximal cervical atherosclerotic stenosis at the time of thrombectomy "may be considered, but the usefulness is unknown" (Class IIb; Level of Evidence C). 1 Immediate cervical stenting may reduce recurrent stroke risk but requires antiplatelet prophylaxis, which increases intracranial hemorrhage risk. 1

Critical Pitfalls to Avoid

Do NOT perform rescue stenting if:

• Initial thrombectomy achieved TICI 2b/3 - no additional intervention needed 1
• Beyond 6-hour window from symptom onset (effectiveness uncertain) 1
• Embolic occlusion without underlying stenosis - standard thrombectomy should suffice 3, 4

Recognize ICAD-related occlusion:

• Significant fixed focal stenosis at occlusion site on final angiography 4
• Temporary bypass achieved during stent retriever passes but immediate reocclusion 4
• Persistent flow limitation despite clot removal 3

Contraindications from Guidelines

The 2021 AHA/ASA secondary prevention guidelines provide a Class III: Harm recommendation stating that angioplasty and stenting should NOT be performed as initial treatment for severe intracranial stenosis (70-99%), even in patients already on antithrombotic therapy (Level of Evidence A). 1 However, this applies to elective secondary prevention, not acute rescue situations after failed thrombectomy. 1

For moderate stenosis (50-69%), angioplasty or stenting is associated with excess morbidity and mortality compared to medical management alone (Class III: Harm, Level B-NR). 1 This further emphasizes that rescue stenting should be reserved for severe stenosis (≥70%) in the acute setting. 1, 3

Practical Algorithm

1. After 3 failed thrombectomy passes with TICI <2b, perform careful angiographic assessment 2
2. Identify underlying stenosis - if ≥70% stenosis present, proceed with rescue stenting 1, 3
3. Consider intra-arterial tirofiban as alternative or adjunct to stenting 1, 4
4. Deploy stent to achieve TICI 2b/3 recanalization 1
5. Initiate antiplatelet therapy based on bleeding risk assessment 1, 5
6. Monitor for reocclusion in first 24 hours 3

Alternative Rescue Strategy

For patients with severe basilar artery stenosis after EVT, intra-arterial GP IIb/IIIa inhibitors (tirofiban or eptifibatide) represent an alternative to angioplasty/stenting, with no difference in symptomatic ICH, mortality, or functional outcome between strategies. 1 This may be preferred when bleeding risk is elevated or anatomic factors make stenting technically challenging. 4