Indications for Use
The SPR® SPRINT® Peripheral Nerve Stimulation (PNS) System is cleared by the FDA under
two regulations.
1. For patients with severe intractable chronic pain:
Regulation: 21 CFR 882.5870
Product code: SCN, “Temporarily Implanted Peripheral Nerve Stimulator for Sustained Pain Relief”
Indication: The SPRINT Peripheral Nerve Stimulation (PNS) System is indicated for pain management in adults who have severe intractable chronic pain of peripheral nerve origin, as the sole mitigating agent, or as an adjunct to other modes of therapy used in a multidisciplinary approach. It is intended to be implanted for up to 60 days and provide sustained pain relief for up to 3 months after the end of treatment.
The SPRINT PNS System is not intended to be placed in the region innervated by the cranial and facial nerves.
The above indications for use statement was supported by a review of clinical data by the FDA. In chronic pain research, responder thresholds of either ≥30% or ≥50% reduction in pain intensity, as well as the use of endpoints that include both pain and other health-related domains, are supported by IMMPACT guidelines1,2. For this review, the FDA used a responder definition of ≥50% reduction in pain intensity to determine the proportion of patients responding to SPRINT PNS at each timepoint. At the FDA’s direction, a clinical data summary (shown below) is included in the Clinician Instructions for Use such that clinicians are informed of responder rates and average reduction in pain intensity among responders at timepoints out to 12-14 months from the start of treatment.
The SPRINT PNS System was studied for the treatment of chronic pain in multiple prospective clinical studies, including case series and multi-center randomized controlled trials. A total of 351 subjects across 13 studies received treatment with the SPRINT PNS System for up to 60 days.
Using data from all 13 studies, the following table provides the responder rates as well as average reduction in pain intensity for responders and for all subjects at each timepoint. Treatment responders are defined as study participants achieving ≥50% reduction in pain intensity as measured by the Numeric Rating Scale (NRS) captured in the Brief Pain Inventory Question 5 in the target area of pain. All subjects who received treatment are included in the analysis (i.e., no subjects are excluded due to adverse events, non-compliance, or other reasons for not continuing the treatment). No imputation of successes or failures was performed for missing data or loss to follow-up.
The responder rates and average reductions in pain intensity represent aggregated data from heterogeneous clinical studies (including both published and unpublished) without formal meta-analyses. The clinical studies had varying study designs, including differences in eligibility criteria, follow-up timepoints, and outcome measures, which may affect the generalizability of the results. Additionally, pooling data from diverse studies without formal meta-analyses inherently introduces uncertainty in the overall responder rates and pain reduction estimates cited below.
Effectiveness when pooling data across all studies on this treatment for chronic pain
| Time Since End of Treatment (EOT) | Number of Responders / Total Number of Subjects | Responder Rate* | Average Reduction in Pain Intensity – Responders Only | Average Reduction in Pain Intensity – All Subjects |
0 days (EOT) | 198/330 | 60% | 76% | 56% |
1-3 months | 176/307 | 57% | 78% | 53% |
4-6 months | 103/234 | 44% | 79% | 45% |
10-12 months | 66/139 | 47% | 78% | 44% |
* Proportion of all subjects with at least a 50% reduction in pain intensity
Clinical data demonstrate that the responder rate was highest immediately after the end of the 60-day treatment period and subsequently decreased to 47% at 10-12 months after EOT. While the proportion of responders fell below 50% between three and four months after the EOT, the duration of clinically meaningful pain relief varied considerably among individual patients.
The most common device-related adverse event reported in clinical studies was skin irritation (which may include inflammation, mild blistering, and/or erythema). Other less-reported events included itching at the electrode exit site, granuloma, pain after electrode placement, and infection. The majority of device-related adverse events were resolved with little to no intervention within a few days, and serious device-related adverse events have been rare.
References:
- Dworkin et al. Interpreting the clinical importance of treatment outcomes in chronic pain clinical trials: IMMPACT recommendations. J Pain 2008;9:105-121.
- Smith et al. Interpretation of chronic pain clinical trial outcomes: IMMPACT recommended considerations. PAIN 2020; 161(11):2446-2461.
2. For patients with acute or chronic pain:
Regulation: 21 CFR 882.5890
Product code: NHI, “stimulator, nerve, electrical, percutaneous (pens), for pain relief”
Indication: The SPRINT Peripheral Nerve Stimulation (PNS) System is indicated for up to 60 days for:
i. Symptomatic relief of chronic, intractable pain, post-surgical and post-traumatic acute pain;
ii. Symptomatic relief of post-traumatic pain;
iii. Symptomatic relief of post-operative pain.
The SPRINT PNS System is not intended to be placed in the region innervated by the cranial and facial nerves.