HONOLULU—A minimally invasive surgical procedure that removes blood clots from brain tissue after hemorrhagic stroke appears to be safe and to reduce long-term disability, according to research presented at the 2013 International Stroke Conference.
Patients with hemorrhagic stroke who received surgery and thrombolysis had less disability, spent less time in the hospital, and were less likely to be in a long-term care facility than other patients with intracerebral hemorrhage, according to the one-year results of the MISTIE (Minimally Invasive Surgery plus rt-PA for Intracerebral Hemorrhage Evacuation) trial.
Daniel Hanley, MD, Professor of Neurology at Johns Hopkins School of Medicine in Baltimore, and colleagues studied 96 patients with hemorrhagic stroke at 26 hospitals. In the stage two arm of the study, 25 patients had the surgical procedure and 31 patients received standard poststroke medical care (ie, only medical management). Patients’ mean age was 60, and 75% of participants were males.
During the procedure, the surgeon cut a hole the size of a dime in the patient’s skull. He or she then passed a catheter into the brain tissue and through the longest part of the clot. Recombinant tissue plasminogen activator (t-PA) was then delivered through the catheter every eight hours for three days. The clot then liquefied and was removed through the catheter.
The average volume of patients’ blood clots was 46 mL, which is roughly the size of a golf ball. The surgery removed 57% of the clots on average. In patients who received standard poststroke care, about 5% of clots naturally dissolved in the few days following the stroke. Patients who had undergone surgery had less edema in the brain four days after the procedure than patients who received medical management only.
One year after the stroke, functional outcomes were 14% better in patients who had undergone surgery than in patients who received standard poststroke care, according to the newest findings of the trial. Also, results at one year were 14% better among patients with mild disability who had received surgery, compared with patients with mild disability who had not received surgery. In addition, 14% fewer surgical patients were in long-term care at one year than patients who had received standard care.
The median time spent in hospital or rehabilitation care at any level was 38 days shorter for patients who had had surgery than it was for patients who received only medical management. The procedure thus could save approximately $44,000 in costs per patient, according to the researchers.
Patients did equally well, regardless of whether they had surgery soon after the stroke or between 36 and 72 hours after the stroke. “The time window for this procedure is more permissive than that for ischemic stroke,” said Dr. Hanley. In addition, the surgery seemed equally effective, regardless of the patient’s ethnicity, gender, or age. Training for surgeons is simple, and the equipment is readily available, Dr. Hanley added.
Delay in Dissolving Clots May Worsen Ischemic Stroke Outcomes
For patients with ischemic stroke, every 30-minute delay in breaking up a blood clot may decrease the likelihood of a good outcome by 10%, researchers reported at the 2013 International Stroke Conference. Other factors such as stroke severity do not appear to alter this correlation.
The results come from a substudy of the Interventional Stroke Management III (IMS 3) trial, which compared the efficacy of IV t-PA alone and t-PA plus endovascular therapy.
In the substudy, Pooja Khatri, MD, Director of Acute Stroke and Associate Professor of Neurology at the University of Cincinnati, and colleagues examined data for 240 IMS 3 patients with major clots in brain arteries who had received IV t-PA and endovascular therapy. Blood flow was restored in 182 patients within seven hours of stroke onset. Patients’ level of disability was evaluated 90 days after they received treatment.
The researchers defined good clinical outcome as a 90-day modified Rankin score of between 0 and 2. Dr. Khatri’s group analyzed angiographic M1, M2, and ICAT occlusions reperfused during the intra-arterial procedure to isolate the effect of time from stroke onset to successful reperfusion.
Time from stroke onset to successful reperfusion ranged from 180 to 418 minutes. Among patients who received successful reperfusion, faster time to reperfusion, NIHSS score of 19 or lower, and lack of prestroke disability were associated with good outcomes in the multivariable model. NIHSS score was similar between patients who were successfully reperfused (ie, 18) and those who were not (ie, 17).
In the larger IMS 3 study, 900 patients with ischemic stroke were to be randomized to IV t-PA alone or t-PA and endovascular therapy. All patients received t-PA within three hours of stroke onset. The trial was stopped in April 2012 after an interim analysis determined that additional therapy was unlikely to benefit patients. Neither t-PA nor t-PA with endovascular therapy proved superior in the trial. Functional outcomes were similar in the two groups, but patients who had an NIHSS of 20 or higher showed a statistically insignificant benefit from endovascular therapy.