Neurointerventional Practice and Its Frontiers

Eskey et al¹ have reviewed the literature concerning diseases and conditions necessitating endovascular neurointerventional procedures with emphasis on updates since the 2009 American Heart Association paper. The authors occasionally note the quality of evidence, though the scope of the paper is a scientific statement and not a true clinical practice guideline with formal evidentiary recommendations. The manuscript surveys the epidemiology, natural history, and general points of management for the major diseases (ischemic stroke, aneurysm, AVM, and dural AVF) for which neurointerventional procedures are performed. It references the major clinical trials and cases series that shape practice and notes the limitations of the evidence for certain diseases and clinical situations in making stronger statements of interventional efficacy. Additionally, the authors review emerging endovascular applications in venous thrombosis, idiopathic intracranial hypertension, and oncology. Overall, the manuscript is an excellent review of neurointerventional practice and services its community in its consolidation and analysis of a productive evidentiary decade.

Over the next 10 years we can expect to see continued advances in imaging and device technology. Given the scale of ischemic stroke and the importance of endovascular intervention, greater scrutiny will be placed on performance standards as it relates to temporal benchmarks and clinical outcomes². As such we should anticipate that the practice will evolve to minimize the symptom onset to intervention interval whether that be through clinical and imaging assessment in the field³,⁴ angio suite-based diagnostic imaging^5,6 more sophisticated thrombectomy devices, and/or dedicated, continuous in-house stroke personnel.

As it relates to aneurysms, the advent of flow-diverting stents has more starkly demarcated endovascular treatments, given their particular success in side-wall type lesions. Their use has also put greater emphasis on aneurysmal flow conditions, characteristics that should become part of reporting practices as the technology becomes more readily available⁷. We should anticipate similar improvement in the treatment of wide-necked bifurcation aneurysms with emerging technologies, both as embolization support and standalone endosaccular devices. Advances in surface coatings⁸ and other device materials may also enable safer usage in the setting of acute hemorrhage. With such progression the technical ease of endovascular treatment will similarly follow. Nonetheless, clinicians should remain focused on patient selection, as the natural history of many aneurysms is benign as well as appreciating the continued role of microvascular surgery for aneurysms anatomically unfavorable to endovascular treatment.

Lastly, as oncological therapies evolve, targeted drug⁹, cell¹⁰, and/or nanoparticle delivery should similarly follow the success of general interventional radiology practice. Imaging and microcatheter technology enables access into very discrete vascular beds permitting concentrated deposition of materials for any number of purposes.

The shifting technological base on which the field rests requires clinicians to continually monitor trends in practice taking care to differentiate commercial novelty from clinically meaningful innovation. The greatest step to ensuring such rigor sits with the group members themselves, a commitment enabled by maintaining standards of training. The seeming generalizability of many endovascular techniques may lure individuals without dedicated neurointerventional training to take on the treatment of stroke in its varied forms. Such practice runs the risk of undermining the decades of evidence built by experts in addition to exposing patients to undue harm either directly through malpractice or practice constraint due to changes in evidence as the techniques are employed outside trial settings. Maintaining a collective focus on neurovascular disorders is best for our field and patients. The ability of our community to support basic research and clinical trials is essential to the health of our specialty.