The U.S. Food and Drug Administration has approved a new implantable device to treat severe back pain that has resisted all other treatments. The device, the Senza spinal cord stimulation system, works by delivering high-frequency electrical pulses to the spinal cord in the range of 10K Hz, but with low stimulation amplitudes.
Other spinal cord stimulators that treat pain are on the market, but have the side effect of a constant tingling sensation. This sensation, called a paresthesia, can be very annoying for some patients.
Senza delivers electrical pulse through small electrodes that are placed near the spinal cord in the mid to lower back. Leads run from these electrodes to a device that in implanted under the skin either on the lower back or abdomen, according to the FDA. The device, which runs on batteries, is approved for use in treating chronic intractable pain of the back or limbs, including low back pain and leg pain, and pain associated with failed back surgery.
Seventy-five percent of subjects who were treated with the Senza System had a 50% reduction in pain after 3 months, and about 55% reduction at 12 months, the FDA said in a statement.
Patients who have chronic intractable pain are first treated for a few weeks with temporary implanted leads and a Senza spinal cord stimulator that is outside the body. If the stimulation works well, the patient undergoes surgery to insert permanent leads and an implanted Senza device.
Chronic back pain is a leading cause of disability in the United States. Acute back and leg pain may last for weeks, but usually goes away after the cause of the pain heals or has been treated. Chronic pain is pain that lasts more than 12 weeks. It may have been caused by an initial injury or infection, but some people have severe chronic pain without any known cause.
Senza is a product of the Nevro Corp. of Menlo Park, CA. The system is already available in Europe and Australia.
