Endovascular thrombectomy (EVT) has become the standard of care for large vessel occlusion in acute ischaemic stroke (AIS). During clot-retrieval, simultaneous balloon inflation within the internal carotid artery offers transient proximal blood flow arrest, potentially preventing distal clot migration or embolisation to new vascular territories. Retrospective studies indicate that this may improve complete vessel recanalisation rates and may translate to improved functional independence. However, lack of high-quality evidence demonstrating the efficacy of simultaneous balloon inflation has led to clinical equipoise with heterogeneity of practice globally.

Inclusion Criteria:

• Age ≥18 years
• Acute ischemic stroke presenting with a neurological deficit of (NIHSS ≥2)
• Intracranial arterial occlusion of the distal internal carotid artery or middle cerebral artery (M1/M2 segments) demonstrated with on clinical neuroimaging such as: computed tomography angiogram (CTA), magnetic resonance imaging angiogram (MRA), or digital subtraction angiography (DSA).
• ASPECTS score of >4 or by locally accepted ischaemic core/penumbra mismatch using computed tomography perfusion or magnetic resonance (CTP or MR) imaging.
• modified Rankin Scale, mRS<3
• Intention to treat with aspiration only or combination technique of stent-retriever + aspiration in the first pass attempt during endovascular thrombectomy

Exclusion Criteria:

• Severe stenosis (>90%), or tandem occlusion of the ipsilateral extracranial internal carotid artery.
• Previously deployed stents in the ipsilateral internal carotid artery.
• Dissections of the ipsilateral internal carotid artery.
• Unlikely to be available for 90 days follow-up (e.g. no fixed home address, visitor from overseas).
• Subject participating in a study involving an investigational drug or device that would impact this study.