Rethinking Training and Distribution of Vascular Neurology Interventionists in the Era of Thrombectomy
2017; Lippincott Williams & Wilkins; Volume: 48; Issue: 8 Linguagem: Inglês
10.1161/strokeaha.116.016416
ISSN1524-4628
AutoresJames C. Grotta, Patrick D. Lyden, Thomas Brott,
Tópico(s)Clinical practice guidelines implementation
ResumoHomeStrokeVol. 48, No. 8Rethinking Training and Distribution of Vascular Neurology Interventionists in the Era of Thrombectomy Free AccessArticle CommentaryPDF/EPUBAboutView PDFView EPUBSections ToolsAdd to favoritesDownload citationsTrack citationsPermissions ShareShare onFacebookTwitterLinked InMendeleyReddit Jump toFree AccessArticle CommentaryPDF/EPUBRethinking Training and Distribution of Vascular Neurology Interventionists in the Era of Thrombectomy James C. Grotta, MD, Patrick Lyden, MD and Thomas Brott, MD James C. GrottaJames C. Grotta From the Clinical Innovation and Research Institute Memorial Hermann Hospital – Texas Medical Center, Houston (J.C.G.); Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA (P.L.); and Department of Neurology, Mayo Clinic, Jacksonville, FL (T.B.). , Patrick LydenPatrick Lyden From the Clinical Innovation and Research Institute Memorial Hermann Hospital – Texas Medical Center, Houston (J.C.G.); Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA (P.L.); and Department of Neurology, Mayo Clinic, Jacksonville, FL (T.B.). and Thomas BrottThomas Brott From the Clinical Innovation and Research Institute Memorial Hermann Hospital – Texas Medical Center, Houston (J.C.G.); Department of Neurology, Cedars-Sinai Medical Center, Los Angeles, CA (P.L.); and Department of Neurology, Mayo Clinic, Jacksonville, FL (T.B.). Originally published13 Jul 2017https://doi.org/10.1161/STROKEAHA.116.016416Stroke. 2017;48:2313–2317Other version(s) of this articleYou are viewing the most recent version of this article. Previous versions: January 1, 2017: Previous Version 1 See related article, p 2042Vascular neurologists (VNs) now have 2 powerful tools to improve outcomes after stroke, intravenous tissue-type plasminogen activator (r-tPA) and endovascular thrombectomy (ET). Among the many common aspects of both treatments, the fastest possible intervention after stroke onset emerges to be paramount.1–3 With r-tPA, it has taken 20 years from approval to be accepted, the subspecialty of VN to be born and trained, and systems of care implemented to speed treatment by improving Emergency Department and pre-hospital management. In contrast, ET based on the 5 positive landmark randomized trials reported in the past 2 years4–8 has been accepted much more abruptly. Yet, the same sort of changes in streamlining systems of care and training and distribution of VN expertise are as necessary for ET as they were for r-tPA to deliver ET as rapidly as possible. The abruptness of this ET revolution, and the redirection of care and resources required, have found the VN community unprepared. Dramatic changes in VN training and distribution are necessary to accommodate the fastest possible ET intervention. Our 3-fold premise to be explored below is that (1) treatment of ET candidates is multifaceted and optimally should include the expertise of a VN, (2) the VN community needs to rethink and retool its workforce to accommodate the most rapid and widespread ET treatment possible, and (3) this should by necessity include training and more widely distributing substantially more VNs to carry out ET.The authors acknowledge that what we propose as a Comment and Opinion diverges from the current standard management, which is to concentrate ET expertise into a few hands at Comprehensive Stroke Centers (CSCs) and have the patient brought to Mecca. Initially, the same model was proposed for r-tPA, but the top 3 enrolling sites in the National Institute of Neurological Disorders and Stroke (NINDS) r-tPA for Acute Stroke trial used the commando approach where the stroke teams were physically deployed from the stroke team hub to enroll and treat patients at community hospitals. Using this approach, 50% were treated within the first 90 minutes from the time last seen normal. Gradually it became clear that faster patient care to provide r-tPA administration could be best served not only at CSCs but also closer to the patient at primary and stroke-ready hospitals. This multilevel stroke center concept has been accompanied by efforts to shortcut unnecessary ED delays, distribute expertise more widely by training more VN and leveraging remote expertise via telemedicine, and more recently speed treatment even more dramatically by using Mobile Stroke Units. The impact of these measures has been and continues to be evaluated through registries and comparative effectiveness studies.9,10 For ET, we propose a similar model, except to do it more quickly rather than waiting 20 years.We suggest that optimal employment of ET in the US requires training and more widely distributing a contingent of a new VN interventionist able to carry out r-tPA, ET, and other aspects of pre- and post-acute management. This is not meant to exclude training and participation of our neurosurgical and neuroradiology colleagues in ET. We support the collaborative efforts of all these specialties to develop common training, guidelines, and research efforts. Furthermore, a wider distribution of ET expertise by neurosurgeons and neuroradiologists outside of the CSC Mecca would be welcome and hopefully will be encouraged by the leadership of those specialties. As senior VNs, however, we hope to awaken our own specialty to what we feel is needed to provide the best care for our patients with acute stroke. For the reasons we will outline, we believe that optimal ET management in the future will benefit from more VN training in ET.Once the measures we outline below are implemented, registries and comparative effectiveness studies should compare outcomes—including number of patients treated, percent recovering, costs, and patient satisfaction—to the current model of centralized care.Optimal Management of Patients With Stroke Involves More Than ET and Benefits From the Expertise of VNsThe results of 9 randomized trials including almost 7000 patients1 confirm the initial findings of the NINDS study despite lingering doubts among a small cadre of vocal non-VN physicians.11 r-tPA is effective across all stroke subtypes and severity, regardless of patient age and other demographics. Treatment response is determined mainly by how fast the drug is given after symptom onset. The vast majority of patients with AIS present with National Institutes of Health Stroke Scale scores 75 000 population, practicing VNs but no CSC or ET capability. This does not include suburban and exurban areas of large cities where VNs practice and where transport to a CSC even by helicopter is associated with substantial delay.Certainly, we need to support our CSCs, particularly those large training centers where triage systems can concentrate appropriate patients with AIS. It is vitally important that we create such triage systems and support such centers because they are critical to enable the necessary training of new ET VNs. But even in those centers, most neurosurgeons carrying out ET usually do other neurosurgical procedures, and interventional neuroradiologists do other diagnostic procedures. One could argue that the US healthcare system should be better organized to facilitate triage to CSCs. This may be appropriate for urban cores and extremely rural areas. However, a substantial part of the population lives in suburban or exurban areas or medium-sized cities where VNs are already in practice. Most hospitals in these areas are without sufficient neurosurgical volume to support full-time neurosurgical, neurocritical care, aneurysm, and other CSC metrics, but many of them do support viable VN practices.Our premise is that it is better for a patient in those environments to be treated in the regional hospital stroke centers covered by a VN who does ET than to take the extra ≥2 hours required for transfer to a CSC and then perhaps further delay if the busy interventional VN, neurosurgeon, or neuroradiologist is already occupied on another case. Analagous to the evolution of our approach to r-tPA therapy, and for the reasons we have articulated, we think that regional distribution of ET-trained VNs can be the model for ET as well. We are not proposing that ET be done at centers that cannot provide adequate pre-, intra-, and periprocedural care, but such care does not require a CSC; we propose that ET can be provided at regional stroke centers by VNs who are appropriately trained and who have created a team of nurses, anesthesiologists, technologists, radiologists, and stroke unit personnel to take care of the patient.Therefore, to provide the most rapid ET treatment to the most patients, we advocate and envision an acute intervention team available 24/7/365 in most stroke centers, primary or comprehensive. In such a scenario, it is unlikely that the interventionist will be occupied 100% of their time by interventions. By staffing the intervention call panel with VNs trained in ET, the medical center gains additional stroke expertise. That benefits the acute patient immediately, during the post-thrombectomy phase and into rehabilitation and ultimately secondary stroke prevention.We recognize that the model of care we propose is not how the clinical trials demonstrating the efficacy of ET were performed. However, clinical trials are not how clinical care is delivered in real life—that is why post-marketing surveillance is needed for new drugs and for new procedures such as ET. The commando model used in the NINDS trial of r-tPA for Acute Ischemic stroke evolved over time to the distributed, regional model we know today. As we have already stated, once the measures we suggest are implemented, registries and comparative effectiveness studies should compare outcomes to the current model of centralized care. These outcomes should include the number of patients treated, percent recovering, costs, and patient satisfaction.What Are the Impediments to Training More VNs to Do ET Outside of CSCs?Experience and practice result in better outcomes, and this is likely the case with ET. Yet, we predict that VNs practicing in regional centers and carrying out ET should be able to achieve the same improved outcomes reported from the positive randomized trials. For example, in the 5 pivotal randomized ET trials,4–8 the mean numbers of cases per 12 months per center were 2.4, 3, 8.2, 9.4, and 22.8. We recognize that the total number of cases done at a given center was probably significantly higher because many patients were likely treated outside of the trials. However, even if we take the 22.8 patients treated with ET in REVASCAT (Randomized Trial of Revascularization With Solitaire FR Device Versus Best Medical Therapy in the Treatment of Acute Stroke due to Anterior Circulation Large Vessel Occlusion Presenting Within Eight Hours of Symptom Onset; the only study where the government mandated a registry of all eligible patients) and add an equal number who were treated outside the trial, the number of patients treated per interventionist would be no greater than what we calculate below considering that the total number treated at each center was usually divided among >1 interventionist.The authors do not purport to know how many cases and their complexity that need to be performed each year to maintain ET skills in practice. This number should be determined by those experts who carry out the procedures and train the practitioners. However, this number, and how much results differ between centers based on the number of cases performed, should be confirmed by registry studies and real-world experience now that the frequency of ET is spreading, and not set at an unreasonably high level. It is estimated that there are at least 600 000 patients with a new AIS in the United States per year. Based on 2016 data from Memorial Hermann Hospital in Houston, ≈16% of AIS presenting to the emergency department via Emergency Medical Services are ET candidates. Recognizing the selection bias of extrapolating from a major stroke center that benefits from preferential triage of severe stroke patients by Emergency Medical Services, let us assume that nationwide 10%, or 60 000 per year, would be ET candidates. This number is likely to increase based on forthcoming data from the DAWN trial that patients who wake up with stroke symptoms or have uncertain onset time also benefit from ET if they have a favorable imaging profile. Based on a previous review of VN manpower in 2012, by 2016, there should be ≈1500 VNs practicing in the United States15 and ≈80 newly trained VN each year. The same review estimated that by 2016, there would be ≈1200 interventionists already practicing in the United States and 100 newly trained interventionists each year, some of whom would be VN. Let us assume that we start training 50% of VN to do ET. So that means 1200+100+40=1340 interventionists in 2017. That computes to 60 000/1340=45 ET patients for every interventionist. One can quibble with the numbers, but even if we continue to train 50% of our VNs to carry out ET (a highly optimistic and likely unnecessarily high projection), as long as they are distributed more widely so that all eligible patients can access them, 45 cases per year might be a reasonable estimate. Based on the results of the 5 randomized trials, this should be enough to result in good outcomes. It is certainly more than the number of aneurysms clipped or coiled per year by most vascular neurosurgeons and more than the number of aortic valves implanted via the transfemoral route by most interventional cardiologists. At Memorial Hermann Hospital in 2016, 440 patients were treated with r-tPA and 102 received ET evenly divided among 3 interventionists. As we train more VN to carry out ET, and imaging capability spreads in the post-DAWN era, we predict that our ability to recognize and triage ET candidates will increase in parallel, so the number of cases per VN should stay fairly constant for the near future.What about practical issues such as on-call? A single interventional VN could not be on 24/7 to handle all the ET cases they would do per year. This is the same dilemma faced by any VN in a regional stroke center who has to cover r-tPA call. The solution in many places is to form a 2- or 3-person group to share call. If all these VN were also trained in ET, the schedule would be the same as r-tPA call.How much training is needed? Appropriate training guidelines have been established by the relevant specialties and must not be shortcut.16 However, although thorough and expert training in all aspect of neurovascular intervention is required, we suggest that it might not be necessary that all VNs carrying out ET outside of CSCs maintain skills to treat aneurysms, AVMs, embolectomies, and other non-ET cases. Those conditions are less time-sensitive, less common, and can be triaged to the specialized CSCs. More of the required Accreditation Council for Graduate Medical Education training year should include study of neurovascular anatomy, emphasis on nuances of existing data and appropriate selection of patients for ET, and preliminary exposure to endovascular techniques. With such added exposure during the Accreditation Council for Graduate Medical Education-approved VN year, sufficient endovascular training could be accomplished within 1 to 2 additional years as recommended in the training guidelines. Finally, smooth and more certain transition from the VN year to the interventional training portion should be coordinated between those in charge of the various phases of the dual training program.VNs certainly have the skills to carry out ET. We see their outstanding results in our practices every day. Interventionists of any specialty are successful in part because of their innate skill. Like everything else, outstanding results are also because of practice, desire, and creation of a successful team. The expertise of our existing VN colleagues trained in ET attests to the fact this is a skill that can be learned by many VNs with the desire and training to do so. Furthermore, building more ET training into our VN training programs will attract more candidates who have the natural skills and desire to become outstanding interventionists.So finally, this brings up motivation. In his recently published autobiography, Springsteen17 attributed his success to "DNA, natural ability, study of craft, development of and devotion to an esthetic philosophy, naked desire, and …a furious fire in the hole that just don't quit burning." Those same attributes are what most successful clinicians would report. There is no question in our minds that after >3 decades of training VNs both the motivation and skill are to be found in most, if not all, neurologists who select a career in stroke. We just need to create the pathway.In summary, we would not consider VN training complete without learning how to administer r-tPA and other evidence-based aspects of acute stroke care. Likewise, the authors advocate a larger part in our VN curriculum for vascular anatomy and angiography and that we should create much more ambitious targets for the proportion of VNs trained to carry out ET.DisclosuresDrs Lyden and Brott reports research funding from National Institutes of Health unrelated to this topic. Dr Grotta reports research funding from the Patient Centered Outcomes Research Institute unrelated to this topic.FootnotesThe opinions expressed in this article are not necessarily those of the editors or of the American Heart Association.Correspondence to James C. Grotta, MD, Mobile Stroke Unit and Stroke Research, Clinical Innovation and Research Institute, Memorial Hermann Hospital – Texas Medical Center, 6410 Fannin St, Suite 1423, Houston, TX 77030. E-mail [email protected]References1. Emberson J, Lees KR, Lyden P, Blackwell L, Albers G, Bluhmki E, et al; Stroke Thrombolysis Trialists' Collaborative Group. 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