Minimally invasive surgery with thrombolysis for intracranial evacuation (MISTIE) for stroke caused by supratentorial hemorrhage, for which open surgical evacuation has shown no benefit, has been studied with results presented at the International Stroke Conference and published in The Lancet.
Treatment with MISTIE decreased mortality at 7 days posttreatment to 1% (2/255) compared with 4% for those who did not have MISTIE (10/251; P = .02). After 30 days, 9% of patients treated with MISTIE had died (24/255) compared with 15% in those not treated with MISTIE (37/251; P= .07)
Despite the decrease in mortality that was achieved at day 7, no functional benefit of MISTIE was seen 1 year after treatment. That is, the percentage of patients with a good outcome (mRS 0-3) vs a poor outcome (4-7) did not differ significantly between those treated with MISTIE (n = 255) and those given medical standard of care therapy (n = 251; P = .33). In more detailed analysis, a 20% improvement on mRS scores was seen, however.
Importantly, a secondary analysis showed that within the group of patients who had MISTIE, there was a significant benefit (adjusted odds ratio [OR] 1.75; P = .03) that was dependent if at least 70% of the clot was removed and the final clot volume was 15 mL or less, both of which were dependent on site and surgeon experience.
Patients were randomly assigned to receive image-guided MISTIE with 1.0 mg alteplase given every 8 hours for up to 72 hours or to receive standard medical care. Assessment of good or poor outcome was adjusted for group differences in prespecified baseline covariates including stability, intracerebral hemorrhage size, age, Glasgow Coma Scale score, stability intraventricular hemorrhage size, and clot location, using a modified intention-to-treat (mITT) population that included all eligible, randomly assigned patients exposed to treatment. The assessment of good vs poor outcome was assessed by a blinded jury of 5 expert physicians who were blinded to treatment.