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Robotics, Miniatures
and Magnets
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High tech
abounds in St. Louis operating rooms.
By Pam McGrath
Imagine this: A camera fitting into a one-inch incision. A surgeon
using a computer to manipulate robotic arms during intricate heart
surgery. A magnet guiding a catheter through the body.
In truth, imagining any of these scenarios isn’t necessary. They
are already being used right here in St. Louis, where cutting-edge,
computer-driven technology has come to the operating room.
Saint Louis University Hospital’s OR1: Among the First in the
United States
Miniature cameras are an essential part of the rapidly developing
field known as minimally invasive surgery. During these procedures,
surgeons make a small incision and insert an instrument that holds
a tiny camera. The camera projects an image on a video screen, allowing
surgeons to see inside the body. The surgeons then manipulate surgical
instruments through other small incisions. Compared to traditional
surgery, patients undergoing these procedures experience less pain
and quicker recovery times.
In April, surgeons at Saint Louis University Hospital began performing
minimally invasive procedures in two state-of-the-art operating
rooms designed specifically for this emerging specialty. The $1.1
million suites are among the first in the United States and the
first in Missouri. Called OR1s, the rooms feature a computer-controlled
system that drives the laparoscopic equipment being used as well
as video monitors and lighting. The capacity exists for immediately
viewing on-screen X-rays, medical records and lab and biopsy results.
Computer stations with touch panels allow nurses to call up information
and make changes to equipment settings.
“Before the OR1s became available, we were continually moving equipment
in and out of operating rooms, which resulted in a lot of wear.
Minimally invasive surgery is highly technology dependent—if your
camera fails, you have to proceed with a traditional surgery,” says
R. Ivan Beretvas, MD, a general surgeon at the hospital and assistant
professor of surgery at Saint Louis University School of Medicine.
“Now all of the equipment we need is built into these operating
suites. It’s like moving from the Model-T to a modern car with an
Onstar communications and navigation system—they both provide transportation,
but one provides it more safely and efficiently.”
Monitors in the operating rooms are connected to other areas within
the hospital and school of medicine, allowing groups of physicians
and medical students to observe live operations and see the images
projected by the miniature camera inside the patients. The capability
also exists to broadcast an operation to remote sites throughout
the country and world. A camera mounted above the operating table
serves the same function as the miniature cameras when traditional
surgeries are performed in the OR suites. The use of such robotic
cameras in operating rooms is a technology far removed from physicians
gazing down from a gallery at a surgical procedure.
“I think one of the primary benefits of cameras in the operating
room is the capability of demonstrating new surgical techniques
and instrumentation to surgeons,” says David Hamlin, a sales representative
with VMI Company of St. Louis. In partnership with John Dattilo
of OmniQuest International, Inc., VMI has designed, revised and
installed 20 robotic camera systems in operating rooms across the
country. These permanently installed systems feature cameras ranging
in size from microcameras to standard broadcast cameras that are
controlled through a remote control panel. An operator can make
cameras zoom, focus, tilt, pan and move along linear tracks—all
in an effort to get the best view of a surgical procedure.
“In addition to broadcasting surgeries for teaching purposes, recorded
surgeries provide important data for research and development of
better instrumentation,” Hamlin says. “Recordings from robotic cameras
also provide an excellent marketing tool for both medical facilities
and product manufacturers. The possibilities for their use are quite
extensive.”
Above:
Bruce D. Lindsay, M.D., Washington University School of Medicine
director of clinical cardiac electrophysiology at Barnes-Jewish
Hospital (right), and his colleague, Mitchell N. Faddis, M.D., Ph.D.,
assistant professor of medicine (left), review images of a model
heart in which a catheter was guided by a new system developed by
Stereotaxis, using a computer-controlled magnetic field.
Transforming the future of cardiac surgery at Barnes-Jewish Hospital
While the applications for minimally invasive surgical techniques
continue to expand, there is an area in which surgeons have been
unable to use them: coronary artery bypass grafting, replacing a
clogged or diseased artery with a healthy blood vessel from another
part of the body. The endoscopic tools used in minimally invasive
surgery are more than three times as long as traditional instruments,
presenting a significant challenge to heart surgeons.
“Imagine trying to sign your name with a 12- to 18-inch pen. You
can do it, but your handwriting would probably be illegible,” says
Ralph Damiano Jr., MD, chief of cardiac surgery at Barnes-Jewish
Hospital and the John M. Shoenberg Professor of Surgery at Washington
University School of Medicine (WUSM). “Heart surgeons have steady
hands, but it’s impossible to hold long instruments steady when
you are working on very small vessels. To date, performing endoscopic
coronary artery surgery by hand has been impossible.”
That impossibility may soon be a thing of the past as Dr. Damiano
and a small number of other surgeons worldwide pioneer computer-assisted
surgery using the Zeus Robotic Surgical System produced by Computer
Motion Inc. of Goleta, Calif. During these procedures, Dr. Damiano
sits at a computer console and manipulates two instrument handles.
The computer rescales the motions, filtering out hand tremors and
relaying the digitally perfected movements to two robotic arms that
hold specialized instrument tips and are attached to the operating
room table. Simple voice commands control the robotic arm holding
the video camera.
Although still in clinical trials, computer-assisted surgery holds
the promise of transforming cardiac surgery. “This technique clearly
enhances our dexterity and performance as surgeons,” Dr. Damiano
says. “In the future, we plan to combine this procedure with new
beating-heart surgical techniques. By eliminating the need for the
heart-lung machine and the large incision in the chest, this approach
is likely to shorten patients’ recovery times and greatly decrease
the pain associated with cardiac surgery.”
Using magnets to navigate through the human body
Two additional clinical trials being conducted at Barnes-Jewish
Hospital involve the use of computer-controlled magnetic fields
to steer catheters within the human body. The Magnetic Navigation
System was developed by Stereotaxis, Inc., a St. Louis-based company
in the field of digital instrument control for interventional, or
catheter-based, medicine. The trials are testing how effective the
system is for electrophysiologic mapping of the heart and for neurovascular
navigation in the brain.
“This system is like a workstation that gathers information from
preoperative imaging modalities such as CTs or MRIs, combines it
with real-time images produced during surgical or catheterization
procedures, and then uses that information to create a three-dimensional
road map showing physicians where they are going within the body,”
says Bevil Hogg, president and chief executive officer of Stereotaxis.
“The system then generates a magnetic field that guides the tip
of a catheter within the road map.”
An array of superconducting magnets surrounding the patient controls
a tiny magnet at the tip of the catheter, just like a compass always
aligns to the Earth’s magnetic field. This magnetic field is stronger,
however, and “North” may be changed by the computer-controlled magnets
in response to commands given by physicians.
“We are currently using the system to map the electrical currents
in the heart, but we hope its precision will allow us to one day
treat complex cardiac arrhythmias, or irregular heart beats, especially
atrial fibrillation,” says Mitchell Faddis, MD, PhD, an electrophysiologist
at Barnes-Jewish Hospital and assistant professor of medicine at
WUSM. Dr. Faddis and Bruce Lindsay, MD, WUSM director of clinical
cardiac electrophysiology at Barnes-Jewish Hospital, are conducting
the clinical trial. “Atrial fibrillation is the most common source
of irregular heart beats, and it is also the most difficult to treat.
The Magnetic Navigation System has the potential of providing us
with the precision we need to guide catheters into the left atrium
of the heart and ablate or destroy the tissue causing the arrhythmias.”
Christopher Moran, MD, an associate professor of radiology at WUSM,
is the principal investigator of the system’s use in steering an
instrument within the blood vessels of the brain to reach an aneurysm,
an abnormal blood-filled dilation of a blood vessel.
“Reaching the site of a brain aneurysm has always been a difficult
procedure, but this new technology has the potential to improve
the way we can gain access to sites in the brain during a procedure
within the vascular system,” Dr. Moran says.
Through the use of these and other advanced computer technologies,
St. Louis-area patients and physicians are reaping benefits that
range from shorter, less painful recoveries to an ability to precisely
diagnose and treat diseases. And that’s worth imagining.
Pam McGrath is a St. Louis-based free-lance writer.
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