FDA Okays Senza SCS System Without Tingling for Chronic Pain

Susan Jeffrey


May 08, 2015

The US Food and Drug Administration (FDA) has approved the Senza spinal cord stimulation (SCS) system (Senza System, Nevro) to aid in the management of chronic intractable pain of the trunk and/or limbs, including pain associated with failed back surgery syndrome, low back pain, and leg pain.

The new system is able to reduce pain without paresthesia, or tingling sensation, by providing high-frequency stimulation at 10 kHz, with low-stimulation amplitudes, a statement from the FDA notes.

"The FDA has approved several other totally implanted spinal cord stimulators for pain reduction, but this system is unique because it delivers a high frequency output of 10 kHz that does not cause a tingling sensation — called 'paresthesia' — in patients," said William Maisel, MD, MPH, acting director of the Office of Device Evaluation at the FDA's Center for Devices and Radiological Health. "Since some patients don't like the paresthesia associated with traditional SCS, this device offers another treatment option."

Before implantation, patients go through a one- to two-week simulation using an implanted trial lead and a model of the stimulus generator that stays outside the body, the FDA release notes.

The system delivers electrical stimulation to the thoracolumbar area of the spinal cord via leads implanted through a small incision in the patient's back. The lead is connected to a rechargeable, implantable pulse generator that is implanted in the patient's upper buttocks region or abdomen. A clinician initially programs the device, and patients can use a remote to control the pulse generator within the output ranges programmed by the clinician.

Approval was based on a clinical study including 198 patients with chronic intractable pain of the trunk and/or limbs who were randomized to either the Senza System test group or to a control group comprising 97 subjects treated with another FDA-approved device that delivers stimulation in the 2–1200 Hz frequency range that produced paresthesia.

Of patients receiving treatment with the system, 75% achieved a 50% reduction in pain from baseline at three months, the primary outcome of the study, and an approximately 55% reduction at 12 months.

There were no stimulation-related neurological deficits, such as weakness in the limbs or tremors, observed for either treatment group. The most common adverse events associated with treatment were pain at the implant site and dislocation of the device lead under the skin.

The FDA also approved the Senza System for stimulation parameters below 10 kHz, the statement adds. For stimulation parameters, similar to those used in the control group and other traditional SCS systems, paresthesia is required.

The company announced in January that they had received an "approvable" letter for the system.

It is already approved in Europe and Australia.


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