HHE Neurology supplement 2018 - Page 13

neurology Mechanical thrombectomy in acute ischaemic stroke Mechanical thrombectomy using state of the art devices has revolutionised the treatment of patients with severe disabling strokes due to large vessel occlusion with proven efficacy in re-establishing intracranial circulation and improving patient outcomes Sanjeev Nayak MBBS MRCP FRCR EQNR EDINR Consultant Neuroradiologist, Royal Stoke University Hospital, University Hospitals of North Midlands NHS Trust, UK Stroke is the second single most common cause of death in the world, with 6.7 million stroke-related deaths each year. 1 The burden of disease (disability, illness and premature deaths) caused by stroke is set to double worldwide by 2030. 1 Stroke affects 152,000 people annually in the UK; that is 1 person every 3 minutes 27 seconds. 2 Large vessel occlusion often causes severe strokes and is associated with high mortality, morbidity, poor clinical outcomes and high societal costs. 3 The benefit of intravenous thrombolysis with recombinant tissue-type plasminogen activator for patients with severe stroke due to large artery occlusion is limited; early recanalisation is generally less than 30% for carotid, proximal middle cerebral artery or basilar artery occlusion. 4 An untreated patient with a severe stroke score (NIHSS >15) would require permanent long-term rehabilitation care with an in-hospital stay of 60–90 days, which costs hospitals around £31,500 per patient. 5 Patients with such severe strokes had a 1-year mortality rate of over 50% as the previous conventional treatment failed in majority of cases. Among those who survived, many (>70%) would require nursing home care. 5 Mechanical thrombectomy using state of the art devices has revolutionised the treatment of patients with severe disabling strokes due to large vessel occlusion with proven efficacy in re-establishing intracranial circulation and thereby showing improved patient clinical outcomes. 6 A new era of acute stroke treatment began in November 2014, when nine published randomised controlled trials of mechanical thrombectomy showed better functional outcome with mechanical thrombectomy compared with best medical therapy (Table 1), leading to a revolution in the care of patients with severe disabling acute large vessel ischaemic stroke. 7 The number needed to treat (NNT) with mechanical thrombectomy for a benefit to functional outcome is as low as 3 (range 3–7). 8 This is more effective than the NNT for percutaneous coronary intervention in preventing death in acute coronary syndromes (NNT 30), and the NNT for carotid endarterectomy to prevent one stroke (NNT 26). 8 Hence, in comparison, MT is one of the most effective treatment innovations of this decade. This treatment, which offers fresh hope that clinicians will be able to reverse the effects of a stroke in some of the most serious cases, was adopted by the Department of Health in April 2017, to be rolled out to the rest of the National Health Service (NHS) in the UK in due course. Table 1 Effect of mechanical thrombectomy compared with best medical therapy on good functional outcome (modified Rankin Score ≤2 at 90 days) Trial Mechanical Best medical therapy thrombectomy n (%) therapy n (%) MR CLEAN 76 (32.6) 51 (19.1) REVASCAT 45 (43.7) 29 (28.2) 25 (71) 14 (40) EXTEND 1A SWIFT-prime 59 (60) 33 (35) ESCAPE 87 (53.0) 43 (29.3) 106 85 (42) THRACE 19 14 THERAPY PISTE 17 (57) 1035 EASI 20 (50)* 14 (38)** *19/35 anterior circulation, 1/5 posterior circulation. **14/32 anterior circulation, 0/5 posterior circulation † Value at 30 days. ‡ Per-protocol population analysis. Adapted from ref 7 13 HHE 2018 | hospitalhealthcare.com Adjusted odds ratio (95% CI) p value 2.16 (1.39–3.38) 2.1 (1.1–4.0) 4.2 (1.4–12) p=0.01 1.70 (1.23–2.33) p<0.001 1.7 (1.3–2.2) 1.55 (1.05–2.30) p=0.028† 1.4 (0.60–3.3) p=0.55 4.92 (1.23–19.69) p=0.021‡ p=0.36