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219126_NCS_Currents_March_2_eMag

MR CLEAN Cleans Up the Confusion on Thrombectomy for Acute Stroke By Sung Bae Lee, MD During the International Stroke Conference (ISC) in 2013, three negative endovascular stroke treatment trials were presented, hatching yet another metaphorical goose egg within the fi eld of stroke therapy. The results from these trials – IMS3, MR RESCUE, and SYNTHESIS – were subsequently published in the New England Journal of Medicine (NEJM) in February 2013 and concluded that mechanical thrombectomy was not superior to medical therapies in treating ischemic stroke. Yet, the conclusions from these studies did not mirror the sentiment of many neurointerventionalists who have witnessed patients benefi tting from acute stroke intervention with the newer- generation devices commonly utilized now but not signifi cantly used in those earlier trials. Despite the methodological concerns over trial design, outdated endovascular stroke devices, and patient selection bias, the study results had to be taken seriously. Indeed, many medical centers considered not offering mechanical thrombectomy for acute stroke intervention. In addition, some secondary payers who had documented arterial occlusion and salvageable brain stopped reimbursements for these procedures. Furthermore, tissue and received timely treatment using the latest generation the list-serve of the American Academy of Neurology Stroke and thrombectomy devices. Vascular Neurology Section echoed the reality that mechanical Despite the signifi cant turnaround within the paradigm of acute thrombectomy would not be a broadly accepted treatment for endovascular stroke intervention, there is still signifi cant work ischemic stroke without better data. that needs to be done and precautions that have to be taken within the fi eld. Due to the positive results from these recent After two years of introspection and renewed commitment, the endovascular trials, a one-size-fi ts-all approach to acute stroke fi eld of acute endovascular stroke intervention rose from the ashes intervention may start to reoccur. This mentality would be, at this past winter with the publication of MR CLEAN in the January best, overzealous and, at worst, harmful to patients and to the advanced publication in the NEJM (N Engl J Med 2015 372;1). recent gains within the fi eld. This Dutch trial was conducted with the newest mechanical thrombectomy devices, most notability, stent retrievers. All Further work is required to create standardized guidelines for the patients who were randomized had non-invasive imaging that evaluation and identifi cation of patients who will most benefi t confi rmed arterial occlusion. Also, the Dutch government did from acute stroke intervention. Additional caution will also need not reimburse for mechanical thrombectomy outside of the to be taken to prevent product manufacturers from having too clinical trial. These three simple yet profound factors helped much sway in driving the guidelines for therapy. clearly highlight the benefi t of endovascular therapy for acute The fi eld of acute stroke intervention is grateful for the ischemic stroke. innovations that have been made possible with newer generation stroke devices. However, acute stroke therapy management must The rate of functional independence, as noted by a modifi ed avoid the situation of the tail wagging the dog. The implications Rankin Score of 0-2, was 13.5% higher in the interventional go beyond improving patient outcome statistics, but involve the arm compared to the medical therapy arm. One out of every ethical and fi duciary responsibilities that healthcare providers have seven stroke patients had no disability because of mechanical to our society. thrombectomy. One out of three to fi ve patients were less disabled as a result of mechanical thrombectomy, according to a With the recent positive results of MR CLEAN and multiple other joint outcome analysis. endovascular stroke intervention trials, a greater responsibility Due to the results of the MR CLEAN trial, the data safety and burden have been placed upon physicians who care for stroke monitoring boards (DSMB) of several ongoing interventional patients to provide not only timely care, but also potentially offer stroke trials reviewed their internal data. The DSMB of Extend IA, expanded options for intervention. In the same manner that the ESCAPE, SWIFT PRIME, and REVASCAT stopped their respective fi eld of acute stroke intervention did not crumble in response to trials, concluding that equipoise no longer existed, and the the study results from 2013 that were previously mentioned, the superiority of endovascular stroke intervention was observed in response to the newly released data in 2015 should be measured each of these trials. in its enthusiasm. The effort of reaching the goal of standardizing the practice The results were presented at the 2015 ISC meeting in Nashville, paradigm for acute stroke intervention is just beginning. TN, this past February. The EXTEND IA and ESCAPE trials were Therefore, we should not get too distracted in the celebration of concomitantly published in the NEJM as an advanced publication new and innovative devices. Let us not celebrate before we cross the same week as the ISC conference. SWIFT PRIME and the fi nish line on behalf of our patients. REVASCAT will be published in the near future. Sung Bae Lee, MD is a neurointensivist and endovascular The resounding consensus is that acute stroke intervention is neurointerventionalist at the Queen’s Medical Center in Honolulu, HI. highly effective and safe in the select population of stroke patients He is an invited guest writer for Currents. 5


219126_NCS_Currents_March_2_eMag
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