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Neuro
Devices Find Their Place in Surgical Market
by Glenn Cornett, senior financial
editor and James Cavuoto, editor
Neurotechnology devices such as implanted
deep-brain stimulation (DBS) systems and spinal cord stimulation systems
have delivered a wealth of new therapeutic advances to clinicians
in neurological and neurosurgical specialties. In recent years, manufacturers
of neurosurgical equipment have returned the favor, developing devices
that improve the process of implanting neurostimulation systems. The
interaction between manufacturers of neurostimulation devices and
vendors of neurosurgical equipment promises to enhance the viability
of both markets.
Brain surgery has always been a complicated endeavor, in large part
owing to the need for craniotomy, which involves the opening of the
skull for surgical access. It routinely requires the surgeon to drill
multiple holes in the skull, followed by sawing between those holes
in order to remove part of the skull.
One of the primary tools at the disposal of neurosurgeons is stereotaxic
surgery, which involves computer display of CT or MRI scans of the
operation site. Stereotaxy systems allow neurosurgeons to navigate
around the brain in three dimensions with the help of the computer
imaging system. DBS systems are generally implanted with the aid of
a stereotaxic surgery system.
In the past, stereotaxy systems have incorporated a head frame that
is screwed directly to the patient’s skull prior to surgery.
The frame helps define a trajectory to the intended site of the DBS
electrodes. Unfortunately, the frame also adds to the trauma that
the patient experiences during the implantation procedure, which many
DBS users cite as the biggest negative factor relating to their device.
A Melbourne, FL company called Image-Guided
Neurologics has recently developed a new frameless stereotaxy
system, which alleviates much of the turmoil associated with the procedure.
The company’s Navigus Trajectory Guide is used in conjunction
with an image-guided workstation. The company is also developing a
new product called Navigus DBA, that is targeted specifically at DBS
implantation. The new device will be able to be used either in the
operating room, or in an MRI environment. When used in the MR environment,
it is adapted with a fluid filled alignment stem visible in the MR
environment. Once aligned, Navigus DBA functions as a stable skull-mounted
guide for the introduction of a surgical instruments or stimulation
lead.
Another manufacturer of neurosurgical equipment is BrainLAB
AG of Munich, Germany. The company’s BrainSuite stereotaxy
system integrates image-guided surgery, intra-operative MRI, microscopy
and visualization, and data management technology. The system incorporates
Siemens’ Magnetom MRI system and a Zeiss OPI microscope. The
first BrainSuite system was recently installed at Staten Island University
Hospital in New York.
One of the most innovative firms in the neurosurgical equipment market
is Stereotaxis, Inc., in
St. Louis, MO. The company targets its stereotaxy systems for clinical
applications in two neurosurgical domains. The first is interventional
neuroradiology (INR), which refers to catheter based treatment of
neurovascular disease such as aneurysms and blood clots. The other
area is minimally invasive neurosurgery. Both domains address expanding,
unmet critical needs, and each has significant limitations due to
current instrumentation and manual techniques.
In January, Stereotaxis received FDA approval for its new Niobe Magnetic
Navigation System, which uses computer-controlled magnets, positioned
external to the body, to steer catheters and guidewires throughout
the cardiovascular system. The system works with Siemens’ Axiom
Artis dFC digital fluoroscopy system, which is used to visualize the
devices as they are navigated. Stereotaxis says the catheter delivery
system may eventually be used to steer DBS electrodes to a precise
location in the brain.
Stereotaxis’ catheter delivery system is being designed as a
minimally-invasive, general-purpose, flexible instrument that can
be navigated along complex paths. Once arrived at its destination,
the device can then be used (conjointly with appropriate devices)
for procedures such as biopsy, neurostimulation, ablation, delivery
of drugs, or delivery of stents or coils.
Stereotaxis hopes that its efforts will expand the number of physicians
that can carry out interventional procedures. There are currently
only about 300 physicians in the U.S. fully trained as interventional
neuroradiologists. There are about 5,200 neurosurgeons in the U.S.,
many of whom would be willing to expand their use of minimally-invasive
techniques if this did not require, for example, an additional two
years of fellowship training.
Recent technology advances at the company include the development
of smaller, lower-cost magnet arrays. Early Stereotaxis magnetic devices
involved large, expensive, liquid-helium superconducting magnets.
The device has already been reduced in weight by more than half, using
permanent rather than superconducting magnets. Mike Kaminski, Stereotaxis
COO, says, “The Niobe system defines a new era in interventional
medicine, one where computers help the physician navigate medical
devices more rapidly and more precisely than they can be navigated
manually, freeing the physician to focus on the patient and the outcome.”
The Stereotaxis system’s ability to control and navigate devices
along the course of brain vessels and along the borders of brain tissue
has been demonstrated in early-stage, FDA-approved human studies.
The number of patients, 30, is moderate, but the results have been
encouraging.
Until now, there has been little or no integrated instrument-image
control, which should be a reasonable, expected application of computer-integrated
surgical automation. The Stereotaxis workstation platform is being
designed and developed to pioneer instrument-image integration, with
the aim of becoming the surgical-instrumentation equivalent of a CAD/CAM
station: an information-intensive, versatile, easily manipulated device
that allows for accurate, precise control of surgical instruments
simultaneously with highly-detailed mapping of the operational domain.
Ease of use is a principal objective. One of the systems under development
uses joystick control similar to that used in many video games. Chief
Executive Bevil Hogg reported at a recent meeting that “a 10-year-old
[using the equipment] beat our doctor to the target site” of
a medical simulation. |
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