For the past ten plus years there has been controversy in medicine about whether tPA (tissue plasminogen activator) was effective in treating acute ischemic stroke (stroke caused by blood clots). Several studies done in the late 1990s that that asked if tPA is effective in preventing stroke damage had seemed to show improvement in stroke outcome if tPA was given within 3-4 hours after onset of symptoms.
Based on those studies, when a stroke patient showed up in the emergency department, there was a big rush to do a brain CT scan (to rule out a hemorrhagic stroke, as opposed to an ischemic stroke) and to determine when the stroke symptoms began. Major hospitals were designated as stroke centers because they were better able to diagnose strokes and treat them with tPA. Smaller and rural hospitals, which did not have immediate access to stroke neurologists, participated in remote evaluation by video with neurologists located at distant facilities. Sometimes, patients were emergently transported by air to a treatment facility.
During the time when this form of treatment was being done, there continued to be controversy about its efficacy. Dueling articles appeared in emergency room medical literature. One article was entitled “The Biggest, Baddest Controversy in Emergency Medicine.”
Unfortunately, more recent studies have concluded that none of the earlier trials and studies in fact showed efficacy of tPA in acute ischemic strokes. The analysis of the earlier trials involves rather complex statistical methods, but the end result was the following conclusion: “Reanalysis of the … trial data with multiple approaches adjusting for baseline imbalances does not support any significant benefits and continues to support harms for the use of [tPA] 3-4.5 hours after stroke onset.” Milne K. After Re-Analysis, No Trials Show Efficacy of tPA in Acute Ischemic Stroke. ACEP Now, Sep. 25, 2020.
During the period when controversy surrounded the efficacy of tPA for acute ischemic strokes, more research was being done on the mechanical removal of brain blood clots to restore blood flow that was blocked (endovascular thrombectomy). During a thrombectomy, a surgeon makes an incision into a blood vessel in the brain. The clot is removed, and the blood vessel is repaired. This restores blood flow. In some cases, a balloon or other device may be put in the blood vessel to help keep it open.
Of course, this complex procedure was also usually only done at larger hospitals that had neurologists, neurosurgeons, and interventional radiologists who could evaluate and perform the procedure. This meant the continued use of triage telemedicine to determine whether a thrombectomy was appropriate, and sometimes emergent transport from a smaller hospital to a hospital able to perform this kind of treatment.
