Some of the most important trends in stroke therapy involve further developments in the area of thrombolytic therapy as well as new insights into the mechanical removal of blood clots in acute strokes through minimally invasive catheter procedures, according to Werner Hacke, University of Heidelberg, and vice president of the World Federation of Neurology, at the XXI World Congress of Neurology (Vienna, 21–26 September 2013).
Thrombolysis accessible to ever more people
Brain tissue can be saved if the affected vessel is re-opened very soon after a stroke. The dissolution of the clot by thrombolysis within 4.5 hours after stroke is currently the only verified effective method, a press release from the WCN states. “Studies presented at the WCN now show that this therapy is by no means reserved for patient care in industrialised countries only, but also can be used successfully in developing countries,” according to Hacke. “Furthermore, there is important evidence that expansion of coverage toward previously untreated patient groups could be possible.” A study from Austria, presented at the WCN, (Greisenegger et al) shows that patients over 80 years old, for whom thrombolysis is not approved so far, can also benefit.
Mechanical thrombus removal: no clear recommendations yet
Discussion on the appropriate application of a new treatment strategy involving mechanical reopening of clogged vessels evoked particular interest at the congress. “Great hope is thus being placed on this method because it has expanded treatment possibilities,” said Hacke. “Very large thrombi—over eight millimetres—can be treated this way, thrombi which cannot be dissolved or at least not sufficiently dissolved with lysis to hinder severe strokes.”
Theoretically, this method can be considered for between 20 and 30% of all strokes. Endovascular treatment currently applies only to 0.2% of stroke patients in Europe, according to a study presented at the WCN by the EFNS Stroke Scientist Panel (Kobajashi et al). The application rate varies considerably in different countries. Indeed, the results of previously published studies also provide no clear recommendation.
The expectations were very high following initial promising experiences with this innovative method. The euphoria was dampened a bit, however, by the publication of three large studies discussed in the New England Journal of Medicine that found no general advantage from the new procedure. “These results are currently a fly-in-the-ointment of emergent optimism,” said Hacke. “Our task now is to clarify through further studies the specific subgroups of those affected who can benefit from the interventional therapy: for example, patients with very severe stroke, with stroke at the base of the skull or stroke at a very early point in the therapeutic window.
“This means that for clinical practice, intravenous thrombolysis remains the method of choice for now,” Hacke concluded. “Further large-scale clinical studies are needed to show which patients stand to benefit from an additional mechanical thrombus removal.”