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Technical standards and practice guidelines: should we? Why now? Why SNIS?
  1. Joshua A Hirsch1,2,
  2. Philip M Meyers3,
  3. John Barr4,
  4. Mary E Jensen5,
  5. Collin Derdeyn6,
  6. Laxmaiah Manchikanti7
  1. 1Interventional Neuroradiology, Massachusetts General Hospital, Boston, Massachusetts, USA
  2. 2Interventional Neuroradiology, Harvard Medical School, Boston, Massachusetts, USA
  3. 3Radiology and Neurological Surgery, Columbia University, College of Physicians & Surgeons, New York, New York, USA
  4. 4Scripps Institute, San Diego, California, USA
  5. 5Interventional Neuroradiology, Departments of Radiology and Neurosurgery, University of Virginia Health Systems, Charlottesville, Virginia, USA
  6. 6Center for Stroke and Cerebrovascular Disease, Washington University School of Medicine, St Louis, Missouri, USA
  7. 7Pain Management Center of Paducah, Kentucky, USA
  1. Correspondence to
    Joshua A Hirsch, Interventional Neuroradiology, Massachusetts General Hospital, 55 Fruit Street, GRB 2, Boston, Massachusetts 02114, USA; hirsch{at}

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SNIS continues to develop and update practice guidelines for the delivery of NeuroInterventional care. This constant project represents a major societal undertaking. On occasion, it has bound our society to other medical groups. However, articulating what we believe to be “the correct” guidelines, at times places us at odds with others over critical issues. Why make this effort? Is it worth it?

In 2001, SNIS (then ASITN) published its first guidelines on NeuroInterventional therapies including aneurysms, arteriovenous malformations, head and neck tumors, epistaxis and acute ischemic stroke.1 2 3 4 5 6 7 8 These guidelines helped to define the “state-of-the-art” and served as a foundation for future clinical and technical advancement.

Other specialty societies as exampled by the American Society of Interventional Pain Physicians have embraced standards and guidelines and worked to involve their membership in the process by educating them in the method of evidence-based medicine (EBM).9 10 11 12 13 14 15

The Institute of Medicine defines clinical guidelines as “systematically developed statements to assist practitioner and patient decisions about appropriate health care for specific clinical circumstances”.16 Such guidelines are statements developed and designed to assist both patient and provider in decision-making about the clinical circumstance that they may encounter. Where possible, clinical practice guidelines are statements of best practice that should be based on outcomes data of the treatments we employ.

In 1989, Congress mandated the creation of the Agency for Healthcare Policy and Research. This agency was given broad responsibility for supporting research, data development and related activities. At the same time, the National Academy of Sciences published a document indicating that guidelines are expected to enhance the quality, appropriateness, and effectiveness of healthcare services. While such conclusions might appear to be self-evident, one could argue that these goals have not been validated in actual practice. As data accumulate on the effect of EBM, proof of outcome improvement must be demonstrated just as we would expect with any new drug or device.

When outcomes data are not robust, guidelines are a reflection of consensus expert opinion. Guidelines should reflect best practice, yet it is apparent that opinions vary. All stakeholders involved in their writing have their own ideas about what constitutes “best practice”. As such, there can even be conflicts over basic terminology—that is, how we describe what we do. We can draw parallels to the social complexity of professional sports. In boxing, there may be multiple concurrent champions reflecting the diversity and governance of multiple certifying bodies. Rest assured, every group that gives the “champ” their belt believes that they correctly represent the needs/desires of their constituency. Similarly, we may believe that right is on our side in advancing standards/guidelines, while others disagree. In this democratic republic of medical opinion, we have an obligation as neurointerventionalists to make our position heard.

Guidelines can best be defended when they are evidence based. By contrast, guidelines based on incomplete data or opinion may be weakened by the perception that they are biased and designed to advance the agenda of some special-interest group. Such fears may be partially allayed by strict adherence to conventional scientific method. When strict adherence to the formal principles and process of evidence synthesis are used in guideline development by a specialty society such as the SNIS, the documents that are developed should have the highest possible level of certainty.17

Guidelines should therefore facilitate implementation of EBM where such evidence exists. EBM can be defined as “the conscientious, explicit, and judicious use of current best evidence in making decisions about the care of individual patients”.18 The term “EBM” has historically covered a broad range of methodologies with more recent definitions emphasizing its synergistic role with clinical experience.19 In fact, a good clinical practice guideline, created on the basis of the best available evidence, is not a substitute for clinical judgment but rather an aide in specific decision-making.20

EBM and its role in the preparation of standards/guidelines have a meaningful role in shaping healthcare policy. Comments by government officials, including but not limited to the current US President, suggest that the importance of evidence-based medical practice will increase. Bearing that in mind, and the sports analogy described earlier, it is remarkable that the process of guideline development has thus far been fairly unregulated. In their landmark article in JAMA, Sniderman and Furberg examined the sources of guideline authority and identified major limitations of the current process of creating them.17 They provide suggestions and point out opportunities for process improvement.21 Despite the challenges a more rigid framework for producing clinical guidelines may pose, the results will certainly justify the means.

Pundits have argued that the critics of EBM are often physicians themselves.22 Why would physicians object to EBM? What sounds like a paradoxical and strange phenomenon becomes easier to explain as one considers the issues. First, most physicians are aware that EBM is variable. The best evidence is often graded Class 1, Level of Evidence A according to the commonly used American Heart Association nomenclature. The class number “1” refers to the quality of the evidence as reflected by the underlying methodology (in this case at least one properly randomized controlled trial), and the letter “A” is a panel rating of the available supporting evidence (in this case strong research-based evidence reflecting multiple relevant and high-quality scientific studies).

For the NeuroInterventional discipline, many procedures do not have Class 1, Level of Evidence A designation. Second, some worry guidelines do not take into account the differences between and among academic medicine and private practice, and regional, cultural and geographic settings. Moreover, there is a perception that guidelines can lead medicine down a path of regimented uniformity—a cookbook approach—that may not account for our individuality as practitioners and the patients we serve.

Which brings us ultimately to the questions posed in the title: should we? Why now? Why SNIS?

Should we continue to develop and update practice guidelines? While there are reasonable doubts, there are also many important reasons in favor of guideline production. People who believe in guidelines point to the fact that individual practitioners using guidelines grounded in EBM can draw upon broader experience and expertise in these consensus statements. In the end, this should permit more proper appropriation of healthcare resources and reliable results.

Why now? Most practitioners would agree that dramatic changes to healthcare are imminent over the next few years. Many healthcare policy experts, manufacturing industry advocates, and politicians extol the benefits of a nationalized healthcare system. Some would argue that the present system of healthcare delivery in many ways resembles a multi-trillion dollar series of “mom and pop” operations. NeuroInterventional services for both vascular and spine diseases could be criticized for non-uniformity across local, national, and international levels.

What we do not do for ourselves, others will do for us. The comparatively insular group of specialists who founded our discipline has been replaced by a far broader group of neurological specialists. Furthermore, several non-neurological disciplines including cardiology and vascular surgery with institutionally and nationally powerful lobbies, are showing real interest in “moving north” to the brain. As the need for coronary intervention wanes,23 the brain represents another vascular bed for these practitioners. Many of these groups have a long history and tradition of creating standards and guidelines for their specialties. For example, as cardiologists begin to brand themselves “neuro-cardiologists”, their governing societies will develop standards and guidelines that they view appropriate. For instance, the Society for Cardiovascular Angiography and Intervention recently generated a white paper on acute ischemic stroke therapy.24 This paper and others like it create the appearance of an emerging discipline within the field of cardiology, instead of the established field of neurointervention within the multispecialty neurosciences. The time is now for neuroscience-based NeuroInterventional specialists to create our vision of appropriate standards and guidelines.

Why SNIS? As the acknowledged leaders of organized neurointervention, and the only group to represent all members of the neurovascular triad (neurology, neuroradiology, and neurosurgery), the Executive Committee of the SNIS believes it is our duty to take the lead in developing these standards and guidelines. When appropriate, we hope that other societies will support these documents as has occurred with our past efforts.

In addition to the previously cited standards and guidelines, SNIS (also known as ASITN) helped to develop and publish several multi-specialty, multi-society guidelines. For example, SNIS members represented our society in development of standards and guidelines for carotid stent-angioplasty.25 26 27 Furthermore, our members routinely participate in standards/guidelines committees organized by other societies—for example, the American College of Radiology. We will continue these efforts as before. Finally, we have participated in the creation of position statements where appropriate,21 and we will continue to participate actively in all of these processes.

As the official journal of the SNIS, the Journal of NeuroInterventional Surgery (JNIS) will be the site of planned publication of standards/guidelines/position statements and all documents appropriate to our constituency. Where suitable, we will seek to jointly publish in other journals that represent allied neuroscience specialties.

The development of clinical practice guidelines is necessarily an ongoing process. Technology changes, and the data which support a current position might evolve over time. All such documents are periodically reviewed and revised as needed. SNIS will continue to remain a leader in the provision of these documents. The Executive Committee continues to seek input and invites interested SNIS members to participate in crafting these documents going forward.



  • Competing interests None.