Indications for Use
Clinician Manual
97035873-01 5 of 75
In addition, 3 patients from this study had their stimulators repositioned due to pain at the original location.
Three patients had reoperations to adjust lead position; 1 patient required 2 reoperations, 1 patient had
the device removed due to infection and later to have a new device implanted. A diabetic patient had skin
problems which required device removal; a new device was later implanted. Two patients had the device
removed due to unsatisfactory pain relief.
The prospective study performed by Villavicencio et al. 2000 included 41 patients with pain of various
etiologies. The majority of the patients, 24 (59%), had Failed Back Surgery Syndrome (FBSS), 7 (17%) had
Complex Regional Pain Syndrome (CRPS I and II), 4 (10%) had neuropathic pain syndrome, and 6 (15%)
were diagnosed as stroke or other. Patients underwent an initial trial period for SCS with temporary leads.
If the trial resulted in greater than 50% reduction in the patient’s pain, as measured by the VAS, the patient
was implanted with a SCS system. In this study, 27/41 patients, 66%, had permanent implants. All patients
were examined after 6 weeks. Pain measurements were assessed at 3-6 month intervals for the rst year and
annually thereafter. The median long-term follow-up was 34 months. A total of 24/27 (89%), reported greater
than 50% reduction in pain. Since the majority of the patients were treated for FBSS, this article supports the
use of SCS for the treatment of FBSS.
In this study, one patient required a revision because of electrode fracture. One patient required removal of
the system due to local infection. One patient required replacement of the IPG due to mechanical failure.
Overall, 16 of 27 (59%) patients required a total of 36 repositioning procedures.
A retrospective analysis performed by Hassenbusch SJ et al. 1995 included patients with chronic lower body
pain, predominately neuropathic pain and pain either midline lower back and/or unilateral or bilateral leg pain
treated over a 5 year period. The study was a comparison of SCS to spinal infusion of opioids. For patients
with radicular pain involving one leg with or without unilateral buttock pain, a trial of SCS was recommended
rst. For patients with midline back pain and /or bilateral leg pain, a trial of long-term spinal infusion was
recommended rst. If the patients failed screening with either of these modalities, the other was then tested.
If the treatment reduced the pain by 50%, the systems were internalized. A retrospective analysis of patients
with unilateral leg and/or buttock pain treated initially with SCS and bilateral leg or mainly low back pain
treated initially with spinal infusions of opioids was then done.
In this study, 42 patients were screened; 26 (62%) patients received spinal stimulation; 16 (38%) received
opioids via a spinal infusion pump. Five patients did not receive adequate pain relief with SCS; 3 (7%) of
these patients underwent trial spinal infusions and had effective pain relief. There were 4 (10%) patients who
underwent a trial of spinal infusion of opioid but did not receive adequate pain relief; these patients were not
tested with SCS. Pain severity was rated using a verbal digital pain scale: “On a scale of 0 to 10 where 0 is
no pain and 10 is the worst pain you could ever imagine, what is your pain now?” 16/26 patients (62%) had
greater than 50% pain relief with SCS. In this study, 2/16 (13%) had greater than 50% pain relief with opioids.
Mean follow-up was 2.1 ± 0.3 years. This analysis supports the use of SCS for intractable low back and
leg pain.
In this study, 7 (17%) patients suffered complications after implantation of the device; 5 (12%) patients
required repositioning of catheter type electrodes and 2 patients required revision of the stimulator generator.
Safety Evaluation
Eleven studies were identied based on the detailed inclusion/exclusion criteria to demonstrate the safety of
the PRECISION System. The studies included a total of 1056 patients that were trialed with SCS systems
and 880 patients that received implants. The table below depicts the number of patients, the number of
events, and the percentage of occurrences of each event compared to the total number of patients. It should
be noted that citations cover both IPG and RF systems. The clinical experience reported in the literature on
RF systems is relevant to determining the safety of totally implantable IPG systems.
