Beyond the status quo: Technical advances in neurosurgery

Nov. 03, 2018

Mayo Clinic offers the latest technology in neurosurgery to maximize patient safety and outcomes. Technical advances are thoughtfully integrated into all aspects of neurosurgical care, from workup and diagnosis through surgery and postoperative care.

"Mayo Clinic is never satisfied with the status quo. We use the latest technology to improve patient outcomes and quality of life," says Alfredo Quinones-Hinojosa, M.D., chair of Neurosurgery at Mayo Clinic in Jacksonville, Florida. Technical advances at Mayo Clinic include:

  • Deep brain stimulation (DBS) and subthreshold cortical stimulation
  • Laser ablation to treat focal epilepsy
  • Focused ultrasound to treat essential tremor
  • The first clinical 7-tesla MRI scanner in North America approved by the Food and Drug Administration (FDA)
  • Magnetic resonance elastography (MRE) to determine intracranial tumor consistency
  • Intraoperative navigation and awake craniotomy to lower risk and maximize the resection of lesions
  • Presurgical simulations to enhance the safety of procedures
  • Cryoablation, laser ablation and other minimally invasive approaches for tumor treatment
  • Cutting-edge treatments for endovascular conditions

Before adopting new technologies, Mayo Clinic assesses the impact on patient care. "It's important to embrace new technology. But it's equally important to avoid investing in technologies that don't improve patient care in a meaningful way," says Bernard R. Bendok, M.D., chair of Neurosurgery at Mayo Clinic in Phoenix/Scottsdale, Arizona.

Mayo Clinic also has a technology development manager to facilitate the translation of neurosurgeons' ideas and innovations into patient care. "Our approach is to take a step back and consider the unmet needs of patients, the existing therapies or tools we have to treat these patients, and what an innovation might provide to advance the practice and patient care," says Justin T. Koepsel, Ph.D., a technology and intellectual property development manager at Mayo Clinic in Rochester, Minnesota. "When we identify innovative solutions, Mayo has the expertise to translate from concept to practice, with a rich history of entrepreneurship and industry partnership."

Enhanced capability to treat epilepsy

Mayo Clinic is at the forefront of new technologies that advance care for patients with medically refractory epilepsy. "There are very few epilepsies that we can't treat," says Jamie J. Van Gompel, M.D., a neurosurgeon at Mayo Clinic's campus in Minnesota.

Deep brain stimulation (DBS) of the anterior nucleus of the thalamus, recently approved by the FDA for the treatment of epilepsy, has been performed at Mayo Clinic for more than a decade. Mayo is also a leader in research aimed at elucidating and refining this technique.

Based on the results of a pilot study, Mayo Clinic researchers hypothesize that successful DBS of the anterior nucleus of the thalamus increases connectivity in the default mode network, raising the threshold for seizure propagation. The researchers note that an inhibitory effect on the hippocampus may also contribute to seizure suppression. In a separate study, Mayo researchers describe a novel use of Fast Gray Matter T1 Inversion Recovery (FGATIR) MRI to improve visualization of the input into the mammillothalamic tract, which may be the true effective site of treatment.

"We're describing new approaches for DBS that we think can have significant benefits for patients. A better understanding of the mechanism of action will also potentially improve DBS targeting," Dr. Van Gompel says.

Chronic subthreshold stimulation of the cortex, which acts earlier than conventional neurostimulation devices to prevent seizure onset, is another treatment pioneered at Mayo. "Subthreshold cortical stimulation uses levels of electrical stimulation low enough to help stop seizure initiation, without causing loss of function in that part of the brain," Dr. Van Gompel says. A clinical trial of an enhanced version of this therapy is in the final stages of planning.

Imaging innovations

Mayo Clinic has long been an early adopter of new imaging technology. The 7-tesla MRI allows for enhanced visualization of pituitary tumors, multiple sclerosis lesions and sources of seizure activity. MRE, which was developed at Mayo Clinic, is used in preoperative assessments to measure tumor consistency and adherence to surrounding tissue — information critical to guiding the surgical approach.

Sophisticated intraoperative navigation and awake craniotomies facilitate less-invasive surgeries. These techniques help lower the risk to eloquent motor and sensory tissue as well as the cortical speech area. Awake craniotomy is used for selected tumor and epilepsy resection and treatment of moyamoya disease.

"Awake craniotomy that is performed by experienced hands can result in more extensive resection, and shorter hospitalizations and better outcomes for patients," Dr. Quinones-Hinojosa says. He is exploring an initiative aimed at improving the patient experience during awake surgery through music and eyeglasses that provide pleasant visualizations.

Mayo Clinic also has the capability to simulate disease behavior and complex surgeries via computer and 3D-printed models of patients' anatomy. "This allows us to assess various options in a risk-free environment and to help patients make the most well-informed decisions possible," Dr. Bendok says. "Simulating diseases and operations also allows for device innovation. Our neuroscience innovation and simulation center is creating new devices and approaches that we hope will serve patients well."

Tumor and endovascular treatments

Mayo Clinic strives to provide minimally invasive approaches whenever appropriate. Cryoablation is used to treat selected tumors in the spine and skull base — an approach that can be particularly helpful if the patient has had previous surgery in the area. Laser ablation can be used to treat recurrent tumors.

Surgery using a tubular retractor system can substantially lower the risk of damaging eloquent tissue during the removal of certain lesions. "This is a challenging procedure. But we have the appropriate teams and tools to remove tumors through a tube without performing a large craniotomy," Dr. Quinones-Hinojosa says.

For patients with intracranial aneurysms, Mayo's neurosurgeons offer modified eyebrow incisions, endoscopic skull base surgery, and transnasal and transcranial endoscopy, aided by neuronavigation technology. "We are now treating aneurysms that were once thought to be untreatable," Dr. Bendok says. "Because of our depth and breadth of expertise, we have neurovascular surgeons who can perform whatever a patient with an endovascular condition needs — including extracranial to intracranial bypass, coiling, stenting or microvascular procedures.

"Mayo Clinic's focus is always on doing what is best for patients," he adds. "Our hope is that increasingly effective neurosurgical technology and interventions will help alleviate suffering and improve quality of life."