NeuroLogic - When Numbers Reveal the Bleeding Obvious
When Numbers Reveal the Bleeding Obvious
Date: March 1, 2010
Brain hemorrhage, we know, is the most lethal form of stroke, particularly for patients with both intracerebral and intraventricular bleeding, where reported mortality rates range from 50 to 80 percent. It’s a medical shock-and-awe that so many die, let alone that such variability exists.
Dan Hanley, however, has put both his conviction and expertise behind a powerful tool that can help improve those odds: data.
Hanley oversees a massive, multicenter randomized study called CLEAR III (Clot Lysis Evaluating Accelerated Resolution) to examine the use of the clot-dissolver, tissue plasminogen activator (t-PA) for speeding away brain hematomas. The data collected from the 40-plus centers involved in the study, he says, will confirm or deny that the method saves more lives and offers better health outcomes than other forms of treatment.
It’s just one of several studies coordinated by the Johns Hopkins Brain Injury Outcomes Services (BIOS) Division, which Hanley directs. For 10 years, the group has served as the organizational hub for outcomes research aimed at brain injury. The division not only helps design and conduct such studies, but also advises on analyzing the mass of data they generate.
Besides Clear III, the team has coordinated multicenter trials on adding ultrasound to clot-busting drugs in treating brain hemorrhages, for example, or on a treatment for induced hypertension in acute stroke. Some drugs and devices that BIOS studies have been part of practice for years, Hanley says. But medicine has lacked rigorous trials to validate them. Brain hemorrhage, he adds, is an especially egregious example: “Even guidelines from the American Stroke Association point out the lack of welldesigned studies.” This new one, he hopes, will change that.
Earlier versions of CLEAR have shown t-PA’s safety and best dosage. This latest one examines any benefits of quickly clearing clotted blood from brain ventricles—an idea animal studies support. Extraventricular drainage alone—using a catheter to drain the blood clot—hasn’t proved greatly helpful. So BIOS suggested a look into supplementing that approach with tPA.
With this technique, surgeons insert an intraventricular catheter once the hemorrhage ends. They then irrigate the clot with t-PA, and allow it to drain over several days. Phase II CLEAR showed a six-month mortality of 20 percent—far lower than anything ever before. In addition, a striking half of the study’s patients regained ability to care for themselves. Safety was high.
If this larger, phase III trial confirms earlier benefits, Hanley says, they’ll have found the first real approach for intraventricular hemorrhage to save lives and counter disability.
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