Stroke; a journal of cerebral circulation
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The Food and Drug Administration has established requirements for protecting the public health by assuring the safety and effectiveness of a variety of medical products including drugs, devices, and biological products, and for promoting public health by expediting the approval of treatments that are safe and effective. The Center for Devices and Radiological Health is the center within the agency that is responsible for pre- and postmarket regulation of medical devices. In this article, we review current regulation of medical devices, research and development programs, pre- and postmarket perspectives, and future considerations of medical devices, particularly as they relate to devices targeting acute ischemic stroke as an example of the process. We also review the Center for Devices and Radiological Health's historical perspective of acute ischemic stroke trials and clinical trial design considerations used in prior studies that have led to US market clearance as they are related to currently marketed devices indicated for acute ischemic stroke.
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Brain aneurysms and vascular malformations can cause cerebral hemorrhages, with devastating consequences for the patients and their families. Since the development of microcatheters and materials used for endovascular embolization, we have witnessed a rapid advancement in the technology and in the number or patients treated with this approach. The aim of this review is to survey recent data relevant to new technologies and emerging treatment strategies in these areas. ⋯ Advancements in technology are rapidly improving the endovascular approach to the treatment of cerebral aneurysms and arteriovenous malformations.
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Review Historical Article
Outcomes validity and reliability of the modified Rankin scale: implications for stroke clinical trials: a literature review and synthesis.
The modified Rankin scale (mRS), a clinician-reported measure of global disability, is widely applied for evaluating stroke patient outcomes and as an end point in randomized clinical trials. Extensive evidence on the validity of the mRS exists across a large but fragmented literature. As new treatments for acute ischemic stroke are submitted for agency approval, an appreciation of the mRS's attributes, specifically its relationship to other stroke evaluation scales, would be valuable for decision-makers to properly assess the impact of a new drug on treatment paradigms. The purpose of this report is to assemble and systematically assess the properties of the mRS to provide decision-makers with pertinent evaluative information. ⋯ Multiple types of evidence attest to the validity and reliability of the mRS. The reported data support the view that the mRS is a valuable instrument for assessing the impact of new stroke treatments.
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Statistical sciences have recently made advancements that allow improved precision or reduced sample size in clinical research studies. Herein, we review 4 of the more promising: (1) improvements in approaches for dose selection trials, (2) approaches for sample size adjustment, (3) selection of study end point and associated statistical methods, and (4) frequentist versus Bayesian statistical methods. Whereas each of these holds the opportunity for more efficient trials, each are associated with the need for more stringent assumptions or increased complexity in the interpretation of results. The opportunities for these promising approaches, and their associated "costs," are reviewed.
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Induced hypothermia is one of the most promising neuroprotective therapies. Technological limitations and homeostatic mechanisms that maintain core body temperature have impeded the clinical use of hypothermia. Recent advances in intravascular cooling catheters and successful trials of hypothermia for cardiac arrest and neonatal asphyxia renewed interest in hypothermia for stroke, resulting in early phase clinical trials and plans for further development. This review elaborates on the clinical implications of hypothermia research in stroke and technical and logistical issues associated with the application of hypothermia.