On the website and in the broadcasts today, BBC Scotland News has been telling this story:
‘A charity working with stroke patients has said a procedure which could transform their treatment should be more widely used in Scotland. A stroke thrombectomy has the potential to reduce the harm done by a stroke. The procedure was carried out 13 times in Scotland last year. Chest, Heart and Stroke Scotland (CHSS) said up to 600 patients could have benefitted. The Scottish government said it was developing a national plan for the procedure. The only Scottish hospital carrying out stroke thrombectomies is Edinburgh’s Western General. It has never been a routine service, but clinicians have operated when they have had capacity to do so.’
Note the implication that lack of capacity is the key factor in constraining this procedure.
This uncritical, unbalanced and poorly researched, BBC report does not consider any of the reasons why the Scottish Government is taking time to assess the safety and efficacy of this procedure before announcing a national plan. Where, for example, is the evidence for the charity’s claims?
A quick literature review might clarify things. I’m not a medic but a social scientist, so I claim no medical conclusions can be drawn here but I do insist that there is evidence that a serious debate is to be assessed before rushing in. Perhaps the strongest indicator is this statement from an online debate in the British Medical Journal (2013) challenging the value of thrombolysis generally (including thrombectomy, see Footnote) for stroke patients:
Do risks outweigh benefits in thrombolysis for stroke? Yes—Simon G A Brown and Stephen P J Macdonald
Emergency physicians are strong advocates of thrombolysis for myocardial infarction because a series of studies in large numbers of patients have clearly and consistently shown that the benefits outweigh the risks. Thrombolysis for stroke does not receive the same unanimous support because the risks are higher and the evidence of benefit is not yet convincing. Of 12 controlled trials on the use of alteplase (recombinant tissue plasminogen activator) for stroke, only two found a benefit as defined by primary outcome measures.1 2 Two were stopped early because of harm,3 4 and the remaining studies had negative findings. This pattern is typical for a treatment that does not work.
Evidence of harm is clear
Randomised controlled trials have consistently found that thrombolysis for stroke is associated with a higher risk of intracranial haemorrhage and early death compared with placebo. For alteplase, excess haemorrhages and deaths in the first seven days have been calculated to be 58 per 1000 cases treated (95% confidence interval 49 to 68) and 25 (11 to 39), respectively, although by 3-6 months death rates are similar whether treated with alteplase or not.5
Evidence of a wider controversy can also be seen in these research titles and/or conclusions:
- Higher Rates of Mortality but Not Morbidity Follow Intracranial Mechanical Thrombectomy in the Elderly (American Journal of Neuroradiology, 2010)
- This indicates a higher rate of death in the thrombectomy patients: ‘At 90 days, the rates of symptomatic intracranial hemorrhage were 1.9% in both the thrombectomy group and the control group (P=1.00), and rates of death were 18.4% and 15.5%, respectively (P=0.60).’ (New England Journal of Medicine, 2015)
- This also indicates higher mortality for older patients, in the search, but I can’t access the full text: Efficacy, safety, and clinical outcome of modern mechanical thrombectomy in elderly patients with acute ischemic stroke (The European Journal of Neurosurgery, 2018)
Higher Rates of Mortality but Not Morbidity Follow Intracranial Mechanical Thrombectomy in the Elderly American Journal of Neuroradiology: http://www.ajnr.org/content/31/7/1181
Thrombectomy within 8 Hours after Symptom Onset in Ischemic Stroke New England Journal of Medicine: https://www.nejm.org/doi/full/10.1056/NEJMoa1503780
Efficacy, safety, and clinical outcome of modern mechanical thrombectomy in elderly patients with acute ischemic stroke Acta Neurochirurgica: The European Journal of Neurosurgery https://link.springer.com/journal/701
Footnote: Thrombolysis, also known as thrombolytic therapy, is a treatment to dissolve dangerous clots in blood vessels, improve blood flow, and prevent damage to tissues and organs. Thrombolysis may involve the injection of clot-busting drugs through an intravenous (IV) line or through a long catheter that delivers drugs directly to the site of the blockage. It also may involve the use of a long catheter with a mechanical device attached to the tip that either removes the clot or physically breaks it up.
Footnote 2: I have a vested interest to declare in having suffered a TIA, ‘mini-stroke,’ a few years back, leaving me with, maybe, only worse balance, awful handwriting and a shortened fuse. My mother may have thought I said a ‘Transient Islamic Attack.’!