The main risk of thrombectomy and thrombolysis in this population is intervening when 2022 there is established disabling ischaemic brain injury. For example, if a person with basilar artery occlusion has irreversible bilateral damage to the pons, they may be left with locked-in-syndrome with complete face and body paralysis but clear consciousness, even if the basilar artery is opened. The committee agreed that it is standard practice to perform brain imaging and look for established tissue damage in the brain regions affected by the arterial occlusion, particularly in the brainstem, before intervening. This reduces the number of people surviving with severe neurological disability. Appropriate CT perfusion imaging or diffusion-weighted MRI sequences should be performed to demonstrate that there is salvageable brain tissue and to seek evidence of established injury to functionally critical areas of the posterior circulation. The outlook for this population without intervention is poor, but good outcomes can be achieved with intervention and there is supportive evidence from treating anterior stroke. Therefore, the committee agreed that thrombectomy, and thrombolysis within its licensed indications, should be considered for people with posterior circulation proximal occlusions and without evidence of irreversible infarction who were last known well up to 24 hours previously. This should be done as soon as possible after presentation because better outcomes are likely with earlier intervention. How the recommendations might affect practice The committee noted that in current practice, around 10% of people presenting with all strokes in the UK are eligible for endovascular therapy. More people are likely to be offered endovascular therapy as a result of these recommendations. The recommendation on thrombectomy together with thrombolysis within 6 hours of symptom onset is aligned with current best practice and the NHS England clinical commissioning policy on mechanical thrombectomy for acute ischaemic stroke. 