Intravenous thrombolysis for ischaemic strokes: a call for reappraisal

Abstract

Sir, Balami et al. (2013) state that intravenous tissue plasminogen activator thrombolysis is beneficial for the treatment of acute ischaemic stroke and that strokes are now a treatable medical emergency. A critical analysis of the data, however, raises doubts about the expansive claims of efficacy made by them and others (Wardlaw et al. , 2012). The aim of tissue plasminogen activator treatment is lysis of the thrombus and recanalization of occluded cerebral arteries, to promptly restore blood flow. To prove therapeutic efficacy of the administered thrombolytic agent, angiographic demonstration of arterial recanalization is critically important as it is the only way, in patients, to conclusively demonstrate that clot lysis has occurred. Arterial recanalization has been assessed using different methods: transcranial Doppler studies, magnetic resonance angiography, CT angiography or conventional catheter angiography. However, these tests have widely variable accuracy and reliability. Conventional catheter angiography is the reference standard because of its superb accuracy for imaging evaluation of arteries. Although transcranial Doppler studies have been frequently used to determine recanalization frequency (Alexandrov et al. , 2001, 2004; Demchuk et al. , 2001; Molina et al. , 2001; Ribo et al. , 2006; Saqqur et al. , 2007) their accuracy in assessing steno-occlusive disease is suboptimal and less than either CT angiography or magnetic resonance angiography studies (Feldmann et al. , 2007; Jauch, 2013). Time of flight magnetic resonance angiography (Neumann-Haefelin et al. , 2004; Davis et al. , 2008; Marks et al. , 2008; Kimura et al. , 2009) is limited by loss of flow signal intensity in stenotic regions (Bash et al. , 2005) and does not provide the same degree of spatial resolution as CT angiography or conventional angiography (Bash et al. , 2005; Cloft, 2005; Jauch, 2013). Overall, …