Image courtesy of Covidien Ltd.
December 19, 2014 — In a landmark study evaluating the addition of stent thrombectomy clot removal to pharmaceutical treatment for patients suffering an acute ischemic stroke (AIS), stent thrombectomy provided a significant clinical benefit when compared to pharmaceutical treatment alone. Results from the Multi center Randomized Clinical trial of Endovascular treatment for Acute ischemic stroke in the Netherlands (MR CLEAN) were published online and will appear in the Jan. 1, 2015, issue of The New England Journal of Medicine ("NEJM"). Findings were also presented at the World Stroke Congress.
The MR CLEAN study evaluated 500 patients suffering from moderate to severe strokes and demonstrated that the addition of intra-arterial stent thrombectomy during early treatment doubled the likelihood of a good neurological outcome beyond using a clot-busting lytic alone. The stent retriever is inserted into the patient's femoral artery starting in the leg and navigated to the site of the blood clot in the brain. Once in place, the physician grabs the clot with the device and removes it. The study also confirmed that there was no increased safety risk with the addition of the procedure.
“The results of MR CLEAN demonstrate that the addition of stent thrombectomy to current pharmaceutical treatment provides a significant clinical benefit to patients,” said Diederik Dippel, M.D., Erasmus Medical Center, Rotterdam. “However, there is much work yet to be done in the fight against this devastating disease, and we would welcome confirmation of our findings in additional randomized studies.”
"This is a highly significant milestone in the treatment for a subgroup of patients with a stroke caused by a large artery occlusion," remarked Istvan Szikora, M.D., president of ESMINT, the European Society of Minimally Invasive Neurological Therapy. He added, alluding to the fact that the battle against stroke care is still not won, that his fellow physicians "must make sure that this delicate technique is being used in proper conditions and delivered by properly trained physicians."
The trial used standard lytic treatment, which could include the lytic IV tPA if indicated. The drug was administered through an intravenous injection. Intra-arterial treatment could consist of IA lytics or mechanical treatment, however in the majority of the patients in the trial a stent retriever was used.
The results show that, in the control arm of the study, the current standard treatment results in good outcomes only 19 percent of the time as characterized by a Modified Rankin Score of 0-2. The treatment arm, using the newest generation of stent retrievers in conjunction with clot busting drugs, was almost twice as likely to result in a good outcome. While these results only apply to the subset of stroke patients who could be treated within six hours of onset and had a blood clot in the forward-most (anterior) arteries of their brain, that population accounts for a large number of stroke victims.
The trial used different vendor’s devices, including Stryker's Trevo Retriever and Covidien’s Solitaire device. Both companies are involved in other trials to gather further data on the effectiveness of their systems. Covidien currently supports a number of clinical studies. Data from the Solitaire FR as Primary Treatment for Acute Ischemic Stroke (SWIFT PRIME), Endovascular Treatment for Small Core and Proximal Occlusion Ischemic Stroke (ESCAPE) and Endovascular Revascularization With Solitaire Device Versus Best Medical Therapy in Anterior Circulation Stroke Within 8 Hours (REVASCAT) studies will be presented in early 2015.
For more information: www.stryker.com, www.covidien.com