Stroke & Neurology
Wiebers was appointed Consultant in Neurology at Mayo Clinic in 1980. He served numerous leadership positions, including as Professor of Neurology, Neurology Division Head and Consultant in Neurology and Clinical Epidemiology during which time Mayo Clinic Neurology was consistently ranked #1 in the United States by U.S. News and World Report. He founded and chaired Mayo Clinic's Division of Cerebrovascular Diseases, which became one of the largest divisions of cerebrovascular diseases in the world and is widely recognized as pre-eminent in the field. Wiebers also co-founded and directed the Mayo Neurovascular Laboratory, which grew to become one of the largest and most respected non-invasive neurovascular laboratories in the United States. In 2000, Wiebers received the Distinguished Career Award from Mayo Clinic and Mayo Foundation and in 2007, following a 30-year career at Mayo, he was honored with a lifetime appointment as Emeritus Professor of Neurology at Mayo Clinic and Mayo Medical School.
Mayo Stroke Center
Wiebers led the Mayo Stroke Center as Program Director and Principal Investigator for 12 years from 1995-2007. This Center represented a large stroke research program at Mayo Clinic funded and supported by a Program Project Grant of the United States National Institutes of Health. The unique medical records systems at Mayo combined with the fact that the large majority of the population obtains its healthcare from a single provider, have made population-based epidemiological studies from Mayo Clinic, The Rochester Epidemiological Project and the Mayo Stroke Center unique resources that have been widely utilized by the U.S. Government and third party payers for healthcare planning in the United States. During Wiebers’ tenure as Program Director, the Center made particular efforts to apply Rochester, Minnesota stroke population data and methodology to other defined populations that were culturally diverse and/or environmentally distinct. Such populations included several cities in different regions of Russia, including: Novosibirsk, Krasnoyarsk, Tynda and Anadyr; the populations of 13 American Indian Tribes in North and South Dakota, Southeastern Oklahoma, and Arizona in the United States; the populations of various ethnic groups in Auckland, New Zealand; and other defined populations on a global scale.
Wiebers played an integral role in three randomized clinical trials funded by the U.S. National Institutes of Health that collectively provided answers regarding whether or not carotid endarterectomy, a widely utilized surgery, was beneficial to patients with carotid artery stenosis (narrowing) that was either symptomatic (causing minor stroke or temporary stroke-like symptoms) or asymptomatic (causing no neurological symptoms).
He served as the Chief Neurological Investigator representing the United States and one of seven Principal Investigators for the North American Symptomatic Carotid Endarterectomy Trial (NASCET), which involved 12 centers in Canada and 33 centers in the United States (refs # 90, 92, 202). He also served as Principal Investigator of the Mayo Asymptomatic Carotid Endarterectomy Trial (MACE) involving the three Mayo Group Practices (refs # 62, 104) and served in an Executive Committee Advisory Role to the Asymptomatic Carotid Artery Surgery Stenosis (ACAS) Trial of carotid endarterectomy involving 20 centers in the United States. Among the conclusions formed from each trial, the NASCET Study provided the first definitive evidence for the beneficial effect of carotid endarterectomy among patients who are otherwise healthy and good surgical candidates who have had minor stroke or stroke-like symptoms within the prior 6 months resulting from carotid stenosis of 70-99%. The potential for modest benefit was also shown for symptomatic patients with carotid stenosis of 50-69%. No benefit could be shown for symptomatic patients whose carotid stenosis blockages were less than 50%, for high-risk surgical candidates or for surgeons with morbidity and mortality rates of greater than 6% (ref# 202). The ACAS study and other smaller trials involving asymptomatic patients provided evidence for modest benefit of carotid endarterectomy among very low surgical risk patients with carotid stenosis between 60 and 99% assuming a surgical morbidity and mortality of 3% or less. There was no benefit from the surgery among asymptomatic patients with stenosisblockages of less than 60% (ref #260, 321). The data from these trials continue to be of considerable importance in helping to guide patient treatment decisions affecting hundreds of thousands of patients per year with carotid artery disease. Following completion of these studies, Wiebers was one of several international experts who helped develop treatment guidelines for this procedure.
Natural History Studies
Wiebers' work over three decades at Mayo also provided unique natural history data for several cerebrovascular conditions, which collectively had a substantial impact on the field of stroke medicine. These conditions included: unruptured intracranial aneurysm (refs #9, 42, 203, 285), unruptured intracranial arteriovenous malformation (ref #52, 83), reversible ischemic neurological deficit /minor stroke (ref #16), asymptomatic carotid bruit (ref #74), asymptomatic carotid stenosis (ref #49), cerebrovascular complications of pregnancy (ref #34, 32), dural arteriovenous fistulae (ref #144) and drop attacks (ref #38). These studies delineated the risks associated with the natural course of the conditions and the effect of various patient characteristics, such as age, gender and associated medical conditions and/or characteristics of involved lesions. This data provided standards for judging the effectiveness of treatment options, for determining the magnitude of these disorders as public health problems and for designing clinical treatment trials to test new therapies.