High-Frequency Spinal Cord Stimulation Therapy in Failed Back Surgery Syndrome Patients with Predominant Back Pain

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High-Frequency Spinal Cord Stimulation Therapy in
Failed Back Surgery Syndrome Patientswith
Predominant Back Pain

• Adnan Al-Kaisy1, Jean-Pierre Van Buyten2, Stefano
  Palmisani1, Thomas Smith1, Iris Smet2
• 1St Thomas' hospital, London, United Kingdom, 2AZ
  Nikolaas, St Niklaas, Belgium

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Disclosure

• Study supported by grant from Nevro Corp (Menlo
  Park, CA)
• CAUTION Nevros Senza system is an
  investigational device limited by Federal (USA)
  law to investigational use. The device is
  approved for use in the European Union.

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Most common locations of chronic pain
5
8
24
15
9
6
18
14
8
4
Introduction

• FBSS
• Each year, more than 1 million spinal surgeries
  are performed in the US with 400,000 cases being
  instrumented. 1
• Roughly half of these are in the lumbosacral
  area. 2
• Despite surgery, approximately 30 of these
  patients fail to improve, as shown by persistent
  back pain. 2
• SCS
• Traditional SCS is a well-accepted option for
  Failed Back Surgery Syndrome (FBSS) patients with
  predominantly neuropathic leg pain. 1, 2
• However, providing adequate and sustained back
  pain relief for patients with predominant back
  pain remains more challenging. 1, 2

1 Frey, Manchikanti, Benyamin, et al. Spinal Cord
Stimulation for Patients with Back Surgery
Syndrome A Systematic Review. Pain Physician.
2009 12379-397. 2 Van Buyten JP, Linderoth B.
The Failed Back Surgery Syndrome Definition
and therapeutic algorithms An Update. Eur J of
Pain Suppl. 20104273-286.
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High-Frequency SCS
Senza? High-Frequency SCS system is a novel SCS
system allows pulse rate up to 10 kHz. Surgical
technique similar to traditional SCS, however, a
useful difference

• Traditional SCS requires intraoperative
  paresthesia mapping
• Potentially uncomfortable for patient
• Can lead to wide range in procedure times
• HF-SCS lead positioning is more efficient
• No paresthesia mapping needed
• Anatomically positioned
• Overlapping leads along midline
• ? Shorter, more predictable procedure times

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High-Frequency SCS FBSS
Senza was evaluated for use in the treatment of
chronic pain in a prospective, open label study. 3

• The study trialed 83 patients with or without
  prior surgery
• The study demonstrated the safety and efficacy of
  the novel therapy
• A subset analysis was conducted for the FBSS
  subset
• This subset includes 67 patients
• The patients were followed-up to 12 months

3 Van Buyten et al, High-Frequency Spinal Cord
Stimulation for the Treatment of Chronic Back
Pain Patients Results of a Prospective
Multicenter European Clinical Study.
Neuromodulation. Accepted for publication
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Baseline Demographics
Baseline Demographics (n67) Baseline Demographics (n67)
Mean age in years 49.6 9.5
Gender 54 Female
Mean years since back pain diagnosis 10
Predominant back pain 91
Failed traditional SCS 18
VAS Back (?SD) 8.4 (? 1.2)
VAS Leg (?SD) 5.4 (? 3.2)
Mean of prior surgeries (range) 2 (1-5)
History of back surgery spinal fusion discectomy laminectomy disc replacement 52 42 40 13
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Trial Results

• 57/66 patients (86) had successful trial (gt 50
  pain relief) and went to permanent implant.
• Notable results given significant number of
  difficult-to-treat patients
• 91 of FBSS cohort had predominant back pain,
  which doesnt respond well to traditional SCS
• 18 of FBSS cohort previously failed traditional
  SCS

Note 1 patient did not complete the trial
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Pain Relief at 12 Months
Average Visual Analog Scale (VAS) for Pain (mean
SEM)
Significant and sustained back pain leg pain
relief despite difficult-to-treat
population. 70 of the patients had 50
back pain relief at 12 months.
N57
N57
N54
p lt 0.001
p lt 0.001
Note Subjects who have successfully passed the
trial and received permanent implant
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Improved Function at 12 Months
Average Oswestry Disability Index (mean SEM)
Severe disability
Sustained reduction in disabilities. 15 point
decrease in ODI at 12 months.
Low disability
N56
N56
N53
p lt 0.001
p lt 0.001
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Excellent Safety Profile

• Device related Serious Adverse Events were
  consistent with standard SCS practice
• There were no therapy-related neurological
  findings.
• No device had to be explanted due to battery life
  issues.

SAE Number of Events
Pocket Pain 4
Wound Infection 3
Lead Migration 2
Loss of Pain Relief 1
Suboptimal Lead Placement 1
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Summary Conclusions

• Despite advances in traditional SCS (i.e.
  transverse tripole, triangular stimulation, etc),
  providing relief to FBSS patients with
  predominant axial low back pain remains very
  difficult.
• This 67 patient analysis of High-Frequency SCS on
  FBSS patients shows
• High trial success rate despite difficult to
  treat patients (91 of the cohort had predominant
  back pain)
• 86 trial phase success rate
• Significant and sustained relief for both back
  pain and leg pain
• 70 responder rate at 12 months
• Sizeable and durable improvement in function
• 15 point reduction in ODI at 12 months
• HF-SCS should be considered as a leading
  therapeutic option for FBSS patients (even those
  with predominant back pain)

CAUTION Nevros Senza system is an
investigational device limited by Federal (USA)
law to investigational use. The device is
approved for use in the European Union.