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Information for Prescribers
WaveWriter Alpha™ & WaveWriter Alpha™ Prime Systems Information for Prescribers
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diagnostic or therapeutic intervention for the same disease/conditions and patient population as the
WaveWriter Alpha and WaveWriter Alpha Prime Systems.
The prospective study by Ohnmeiss et al. 1996, examined the long-term effectiveness of SCS in patients
with intractable leg pain. Forty patients were implanted with SCS systems and evaluated at 6 weeks, 12
months, and 24 months follow-up. Outcome measures included the VAS, pain drawings, medication use,
SIP (Sickness Impact Prole), isometric lower extremity testing, and patient questionnaires. An intent-to-
treat analysis was performed. After patients had SCS for 24 months, leg pain, pain when walking, standing
pain, pain’s effect on overall lifestyle, and the total analog scale scores were signicantly improved from
baseline. In this study, 25% of the implanted patients had greater than 50% improvement in pain rating.
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.