Preliminary findings of the minimally-invasive surgery plus rtPA for intracerebral hemorrhage evacuation (MISTIE) clinical trial.

INTRODUCTION: Compared to ischemic stroke, intracerebral hemorrhage (ICH) is easily and rapidly identified, occurs in younger patients, and produces relatively small initial injury to cerebral tissues--all factors suggesting that interventional amelioration is possible. Investigations from the last decade established that extent of ICH-mediated brain injury relates directly to blood clot volume and duration of blood exposure to brain tissue. Using minimally-invasive surgery plus recombinant tissue plasminogen activator (rtPA), MISTIE investigators explored aggressive avenues to treat ICH.

METHODS: We investigated the difference between surgical intervention plus rtPA and standard medical management for ICH. Subjects in both groups were medically managed according to standard ICU protocols. Subjects randomized to surgery underwent stereotactic catheter placement and clot aspiration. Injections of rtPA were then given through hematoma catheter every 8 h, up to 9 doses, or until a clot-reduction endpoint. After each injection the system was flushed with sterile saline and closed for 60 min before opening to spontaneous drainage.

RESULTS: Average aspiration of clots for all patients randomized to surgery plus rtPA was 20% of mean initial clot size. After acute treatment phase (aspiration plus rtPA), clot was reduced an average of 46%. Recorded adverse events were within safety limits, including 30-day mortality, 8%; symptomatic re-bleeding, 8%; and bacterial ventriculitis, 0%. Patients randomized to medical management showed 4% clot resolution in a similar time window. Preliminary analysis indicates that clot resolution rates are greatly dependent on catheter placement. Location of ICH also affects efficacy of aggressive treatment of ICH.

CONCLUSION: There is tentative indication that minimally-invasive surgery plus rtPA shows greater clot resolution than traditional medical management.