Outpatient surgical heat
treatment zaps lower back pain
BY MIKE GOODKIND
A heat-conducting wire
that repairs tears inside the wall of painful spinal
discs may offer relief to about half the 3 to 6 million
Americans who suffer from lower back pain.
In a recent study of the
thermal treatment, 80 percent of the 25 patients who
received the procedure reported measurable declines in
pain, and/or significant improvements in their ability to
perform routine tasks such as sitting, according to
physiatrists Joel and Jeffrey Saal, both MDs and clinical
associate professors of functional restoration at
Stanford University School of Medicine.
Joel
Saal, MD, uses a fluoroscope to guide a thermal therapy
catheter inside hard-to-reach places in spinal discs to
relieve lower back pain. Saal and his brother, Jeffrey,
have developed the promising thermal therapy treatment.
The 15-minute outpatient
surgical procedure targets the nerves that exist in
spinal discs. Cracks and fissures occur in the wall of
the disc over time and are directly responsible for pain
in about 50 percent of people with severe lower back
pain, explained Joel Saal in a recent interview. The
thermal procedure is designed to treat this ailment,
called chronic discogenic low back pain. Saal stressed
that it is not appropriate, however, for patients whose
lower back pain is caused by nerve compression, when the
discs press against the nerves in the surrounding tissue.
To apply the thermal
treatment, physicians must first identify which one of
the five lower discs in the spine is the source of pain.
The physiatrists then insert a catheter loaded with a
temperature-controlled coil into the problematic disc.
Using a fluoroscope, the catheter is navigated deep into
the leather-like wall made of collagen, Saal explained.
The thermal element inside
the catheter, or wire system, is heated to 195 degrees
Fahrenheit, warming the nerves and surrounding collagen
to 140-150 degrees. The heat melts or "turns
off" the nerve endings and contracts and thickens
the surrounding collagen or tissue, said Saal, who noted
that the procedure helps to ensure a stronger, more
stable back that is able to support more weight and help
increase endurance.
"We had to find a way
to deliver heat selectively in a hard to reach place, and
the catheter therapy seemed to be the best way to do
this," Saal said.
The Saals reported the
results of the thermal treatment study at the meeting of
the American Spine Society in San Francisco last October.
As of Feb. 1, a total of 200 patients had been treated
since the Saals initiated the procedure in August 1997,
Joel Saal said.
The thermal technology has
been used to stabilize loose shoulder joints for about
five years but had not been applied to the disc until
physicians could design a precise delivery system, he
explained.
Saal said he and his
brother had rejected other heat-producing technologies,
such as lasers or radiofrequency systems, for technical
reasons. These included the inability to achieve
consistent temperature or accuracy in delivering the heat
to a precise location.
Patients who participated
in the initial study had been previously treated without
success by either the Saals or their colleagues. All of
these patients were in sufficient pain or had a
significant loss of function to warrant interbody fusion
surgery. Fusion surgery is a major inpatient procedure
that works effectively for about 70 percent of patients,
who then face the tradeoff of a long recovery period and
restricted motion.
"Lower back pain is
one of the most difficult longstanding problems in
medicine," said Saal. "Almost all of our
patients have tried many other remedies, including
therapeutic exercise, physical therapy, cortisone
injections, or pain killing drugs, before finding relief
from this outpatient thermal procedure."
Before the procedure, Saal
said patients were often unable to perform routine daily
tasks, such as mowing the lawn, pushing a vacuum cleaner,
or even sitting.
Patients in the current
study were followed from six to 12 months. Ten of the 19
patients who were taking narcotic pain killers prior to
the treatment were able to give up their use of pain
medication, and four more were able to cut their intake
by more than 50 percent, the doctors said.
Eighty percent of the 25
patients reported significant reduction in pain, and 72
percent said they could tolerate sitting longer.
The catheter treatment has
been approved by the FDA and is manufactured by Oratec
Interventions Inc., a Menlo Park-based company founded by
the Saal brothers.
In addition to their
Stanford teaching duties, the Saals practice physiatry
with the Sports, Orthopedic and Rehabilitation group in
Menlo Park. SR
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