Neurointerventionalist Neurosurgeons
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The face of interventional neuroradiology and endovascular neurosurgery is changing. For more than 30 years, the vast majority of neurointerventionalists have been neuroradiologists. In the past five to seven years, however, increasing numbers of neurosurgeons are also training to become neurointerventionalists. Reflecting this wider professional umbrella, the American Society of Interventional and Therapeutic Neuroradiology recently changed its name to the Society of NeuroInterventional Surgery.

This change has been reflected at Mayo Clinic, where two dual-trained neurosurgeons, Ricardo A. Hanel, M.D., and Giuseppe Lanzino, M.D., have joined the staff of Mayo Clinic in Florida, and Mayo Clinic in Minnesota, respectively.

Dual training is rare. As Dr. Lanzino points out, a major benefit is that hands-on experience with both open and endovascular procedures helps guide optimal management. Dr. Hanel agrees, noting that dual training gives the neurosurgeon a different perspective and greater flexibility in considering treatment options.

At Mayo Clinic in Minnesota, Dr. Lanzino has joined an interventionalist team that includes neuroradiologists Harry Cloft, M.D., Ph.D., and David F. Kallmes, M.D., as well as nine neurologists and four neurosurgeons who specialize in vascular disorders. In addition to open procedures, Dr. Lanzino performs endovascular surgery one day a week. His colleagues Drs. Cloft and Kallmes do so five days a week. Together, they provide round-the-clock coverage for endovascular neurosurgical cases.

At the Florida campus, Dr. Hanel is part of a team that includes two neurointerventionalists, two vascular neurosurgeons, and five vascular neurologists. Together they make up one of the largest neurovascular teams in the region, and in the past year, the volume of cases involving vascular lesions has markedly increased. During that time, for example, the number of aneurysms treated at Mayo Clinic in Florida increased seven-fold. About 60 percent of those were treated endovascularly and the rest by craniotomy and clipping.

Endovascular coil treatment (top) and clipping

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Weighing Risks and Benefits

Neuroendovascular procedures include embolization for arteriovenous malformations (AVMs), arteriovenous fistulas, and cerebral aneurysms; thrombolysis for cerebral emboli; and angioplasty and stenting for cerebrovascular stenosis. Neuroendovascular surgery is less invasive than open surgery and can translate into shorter recovery times.

Five years ago, the vast majority of aneurysms were clipped in an open procedure rather than coiled in endovascular surgery. Today that ratio is reversed. Neuroendovascular surgery provides another, sometimes safer, option for managing some neurovascular lesions. Studies have shown, for example, that neurointervention for basilar tip aneurysms gives patients a 2-fold improvement in morbidity and mortality compared with outcomes from an open procedure.

As Dr. Hanel notes, however, just because it is less invasive, a neuroendovascular procedure may not always be the best option. For example, a craniotomy might be the better choice for a middle cerebral aneurysm with a large neck that requires several stents and carries the risk of clotting. The open procedure might actually take much less time and be the more straightforward approach. A dual-trained neurosurgeon is in a good position to weigh the potential risks and benefits and to communicate them directly to the patient.

Endovascular Surgery Fellowship—Crossing Subspecialty Lines

Another change in the profession has been certification of training programs by the Accreditation Council for Graduate Medical Education and recognition of endovascular surgery as a subspecialty by the American Medical Association. A fellowship called Endovascular Surgical Neuroradiology is open to physicians with training in neurology, neurosurgery, or radiology and is offered at Mayo Clinic.

Brian W. Chong, M.D., a neuroradiologist at Mayo Clinic in Arizona, and his neurosurgical colleague, Richard S. Zimmerman, M.D., have been strong supporters of crossing specialty lines within neurointervention. They see the training program as an embodiment of that effort. Dr. Chong notes that the name of the subspecialty and the number of disciplines to which it is open "speak to the multidisciplinary nature and the multiple skills needed to practice neurointervention."

The interdisciplinary nature of the subspecialty is second nature to neurovascular physicians throughout Mayo Clinic. For example, Dr. Chong is one of three neuroradiologists who conduct endovascular surgery at Mayo Clinic in Arizona. He has his own outpatient clinic; however, he collaborates regularly with the other neurovascular specialists. He and Dr. Zimmerman consult on every aneurysm patient. Dr. Chong says, "Although we are from different disciplines, together we act as one. I attribute this entirely to the multispecialty model of care that defines Mayo. It works well because that is what Mayo Clinic is — multiple disciplines taking care of the patient in concert."

Providing Options and Tailoring Treatment

Deciding on the optimal procedure is best arrived at in a climate where there is no vested interest in the approach taken and there is close and open communication between neurosurgery and neuroradiology. A young patient with an unruptured AVM, for example, might benefit from open surgery, radiosurgery, embolization, or a combination of all three approaches, depending on the size and location of the AVM and the patient's age, history, and perspective.

At Mayo, multispecialty cooperation extends beyond neurosurgery and radiology. For example, as noted by Dr. Cloft, Mayo Clinic in Minnesota is one of the few institutions in the world with "the anesthesia resources that allow us to conduct an angiogram that includes possible endovascular surgery right then and there." The interventionalist can discuss the results with a neurosurgeon while the patient and anesthesia team wait in the operating room. As he says, "It is a patient-friendly atmosphere. A lot of our patients travel some distance to Mayo, and they don't want to wait days for a decision."

Whether in the person of a dual-trained neurosurgeon or in the case-by-case consultation between neurovascular specialties, having the perspective of both neurointervention and open surgery is critical in providing optimal care for surgical candidates. Drs. Hanel and Lanzino, both dual-trained, cite the collaboration among members of the neurovascular teams throughout Mayo Clinic as making the difference for patients because treatment is always individually tailored.