Eroding interventional neuroradiology turf raises red flag
During the past decade, neuroradiologists have created and perfected interventional procedures to treat aneurysms, acute infarction, and carotid stenosis. But competition from nonradiologists will continue to grow unless the discipline produces more well-trained interventionalists.
A survey of academic and nonacademic centers in the U.S. and Canada found that radiologists perform 88% of interventional neuroradiology procedures. But the researchers concluded that the study probably identified the lower limit of nonradiologist participation (12%), particularly since cardiologists, vascular surgeons, and neurosurgeons were not directly polled.
"We believe that these results should be of great concern to the radiologic community, especially in view of the current shortage of radiologists," the authors wrote in the October issue of the American Journal of Neuroradiology.
The researchers also noted that even as the stature of neuroradiology has grown, fellowships in the discipline have gone unused, programs have decreased in size, and some programs offer no training in endovascular interventional procedures. Neurosurgeons are in some cases filling neuroradiology fellowships and adding to the ranks of the American Society of Interventional and Therapeutic Neuroradiology.
Dr. David P. Friedman, codirector of neuroradiology, and Andrea J. Maitino, an assistant researcher, both at Thomas Jefferson University Hospital, sent a survey to 102 neuroradiology fellowship program directors (academic centers) and to 146 senior members of the American Society of Neuroradiology, who were not affiliated with fellowship programs (nonacademic centers).
They received a 56% and 48% response rate from academic and nonacademic centers, respectively. A total of 4361 procedures were reported, including 2283 Guglielmi detachable coil (GDC) embolizations, 949 carotid-vertebral artery thrombolysis procedures, and 1129 carotid stent placements with angioplasty.
Academic centers performed the bulk of the procedures (84% vs. 16%) and had more nonradiologist involvement (14% vs. 5%). Competition for GDC embolizations comes strictly from neurosurgeons. Cardiologists, neurologists, and neurosurgeons vie with radiologists in treating acute infarction, while vascular surgeons round out the same group in competing for carotid stenting.
Researchers predict a continued incursion by neurosurgeons into GDC turf because the procedure can replace surgical clipping in certain circumstances. The greatest competition from nonradiologists (especially cardiologists) occurred in carotid stenting. That battle could heat up once randomized studies validate the procedure's long-term efficacy and practitioners begin to use it as a primary treatment for atherosclerotic disease.
Three nonacademic centers revealed that they already use carotid stenting as a primary treatment for carotid disease. Additionally, all patients are enrolled in a protocol evaluating the efficacy of the procedure.
Conventional cerebral angiography also faces turf encroachment from nonradiologists. At 18% of the academic centers and 15% of the nonacademic centers, neuroradiologists and cardiovascular radiologists share conventional angiography duties with nonradiologists. At one academic center, radiologists performed no angiography.
The angiography figures are comparable to those for the interventional procedures evaluated in the survey, according to the researchers. Consequently, they predict a rise in nonradiologists' participation in diagnostic head and neck angiograms as more of them become proficient in performing the interventional procedures.
"The radiologist could be removed from the decision-making process regarding the need for conventional angiography -- as opposed to, for example, CT angiography or MR angiography," the authors wrote.
They expressed concern about two other findings of the survey: the concentration of a few centers performing the bulk of the interventions and the lack of centers performing intra-arterial thrombolytic therapy.
Fewer than 10% of all centers surveyed performed approximately half of all of the neuroradiological interventions, while 12 centers performed 45% of the intra-arterial thrombolysis. As some thrombolysis cases could be the result of in-hospital complications, intra-arterial therapy for acute infarction could be even less common than reported, the researchers said.
Although intra-arterial thrombolytic agents are not FDA-approved for carotid-vertebral thrombolysis, off-label use is completely permissible and, in certain cases, represents the standard of care, according to the authors. However, many physicians might misunderstand the concept of "off-label," which adds to the underutilization of this therapy, they said.
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