Treating Chronic, Intractable Pain with a Miniaturized Spinal Cord Stimulation System: 1-Year Outcomes from the AUS-nPower Study During the COVID-19 Pandemic.

Purpose: Spinal cord stimulation (SCS) is a highly effective treatment for chronic neuropathic pain. Despite recent advances in technology, treatment gaps remain. A small SCS system with a miniaturized implantable pulse generator (micro-IPG; <1.5 cm3 in volume) and an externally worn power source may be preferred by patients who do not want a large, implanted battery. We report here the long-term outcomes from the first-in-human study evaluating the safety and performance of a new neurostimulation system. Patients and Methods: This was a prospective, multi-center, open-label, single-arm study to evaluate this SCS system, in the treatment of chronic, intractable leg and low-back pain. Consented subjects who passed screening continued on to the long-term phase of the study. One-year, patient-reported outcomes (PRO's) such as pain (Numeric Rating Scale, NRS), functional disability, quality of life, and mood were captured. Results: Twenty-six (26) evaluable subjects with permanent implants were included in this analysis. The average leg pain NRS score decreased from 6.8 ± 1.2 at baseline to 1.1 ± 1.2 at the end of the study (p < 0.001), while the average low-back pain NRS score decreased from 6.8 ± 1.2 to 1.5 ± 1.2 (p < 0.001). The responder rate (proportion with ≥50% pain relief) was 91% in the leg(s) and 82% in the low back. There were significant improvements in functional disability (Oswestry Disability Index) and in mood (Beck Depression Inventory), demonstrating a 46% and 62% improvement, respectively (p < 0.001). Eleven-point Likert scales demonstrated the wearable to be very comfortable and very easy to use. Conclusion: There were considerable challenges conducting a clinical study during the COVID-19 pandemic, such as missed study programming visits. Nevertheless, subjects had significant PRO improvements through 1-year. The small size of the implanted device, along with a proprietary waveform, may allow for improved SCS outcomes and a drop in incidence of IPG-pocket pain.

Spinal cord stimulator explant caused by post-incisional cellulitis secondary to Varicella Zoster Virus (shingles) infection: a case report.

INTRODUCTION: Spinal Cord Stimulation (SCS) is a well-established therapy for refractory neuropathic pain, known for its safety and minimally-invasive nature. However, complications, including surgical site infections (SSIs), can arise post-implantation. SCS-related SSIs occur in 3.4% to 4.6% of cases within 90 days post-implant, often requiring device removal and impacting pain management and healthcare costs. The impulse generator, electrode implant site and lumbar/thoracic surgical site are commonly affected, with local skin flora and circulating organisms being the primary causes of infection. CASE PRESENTATION: An 80-year-old Lebanese male with chronic neuropathic lower back and bilateral leg pain, significantly impairing function, underwent prolonged hospitalizations for COVID-19 infection and acute-on-chronic pain with Urinary Tract Infection (UTI). Considering SCS as a therapeutic option, a successful trial led to permanent implantation, resulting in improved pain severity and functional capacity. However, three months later, the patient developed post-incisional cellulitis and wound dehiscence secondary to Varicella Zoster Virus (shingles) Infection directly over the Implantable Pulse Generator (IPG) incision line. Despite antibiotic treatment, the infection progressed, necessitating SCS system explantation. DISCUSSION: This represents the first reported case of VZV infection causing wound dehiscence and SCS explantation post-implantation. Contributing factors may include itching around the IPG site, facilitating deeper tissue inoculation. Laboratory and imaging tests may not reliably detect SSIs, and superficial infections may respond to antibiotics, while deep infections typically require implant removal. Early identification and intervention are vital to minimize complications. CONCLUSION: This unique case emphasizes the need for heightened vigilance and monitoring in patients with viral infections near medical devices. A standardized approach to assessing and managing SCS-related infections is critical. Sharing such experiences contributes to improved understanding and treatment of these rare incidents.

Early Experience With a Novel Miniaturized Spinal Cord Stimulation System for the Management of Chronic Intractable Pain of the Back and Legs.

INTRODUCTION: A novel, spinal cord stimulation (SCS) system with a battery-free miniaturized implantable pulse generator (IPG) was used in this feasibility study. The system uses an external power source that communicates bidirectionally with the IPG (< 1.5 cm3). Human factors, subject comfort, and effects on low back and leg pain were evaluated in this first-in-human study. MATERIALS AND METHODS: A prospective, multicenter, open-label clinical trial was initiated to evaluate the safety and performance of a novel miniaturized stimulator in the treatment of chronic, intractable leg and low-back pain. Eligible subjects were recruited for the study and gave consent. Subjects who passed the screening/trial phase (defined as ≥ 50% decrease in pain) continued to the long-term implant phase and were followed up at predefined time points after device activation. Interim clinical and usability outcomes were captured and reported at 90 days. RESULTS: Results of 22 subjects who chose a novel pulsed stimulation pattern therapy using the battery-free IPG (< 1.5 cm3) are described here. At 90-days follow-up, the average pain reduction was 79% in the leg (n = 22; p < 0.0001) and 76% in the low back (n = 21; p < 0.0001) compared with baseline. Responder rates (≥ 50% pain relief) at 90 days were 86% in leg pain (19/22) and 81% in low-back pain (17/21). Subjects rated the level of comfort of the external wearable power source to be 0.41 ± 0.73 at 90 days on an 11-point rating scale (0 = very comfortable, 10 = very uncomfortable). DISCUSSION: These interim results from the ongoing study indicate the favorable efficacy and usability of a novel, externally powered, battery-free SCS IPG (< 1.5 cm3) for leg and low-back pain. Study subjects wore the external power source continuously and found it comfortable, and the system provided significant pain relief. These preliminary findings warrant further investigation. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is ACTRN12618001862235.

Satisfaction With Chronic Pain Treatment.

BACKGROUND: The effects of chronic pain (CP) on physical function and emotional and mental health of individuals, families, and community are well established. No adequate research is conducted in this field in Iran. OBJECTIVES: The current study aimed to assess the prevalence of CP, types of treatments used for CP and patients' satisfaction with the CP treatments in an Iranian urban population. PATIENTS AND METHODS: In the current study, CP was investigated using the international CP questionnaire administered to 1,050 adults living in Shiraz, Iran. The questionnaire consisted of 28 questions used to evaluate the effects of CP on the studied population including the prevalence of CP, pharmacological and non-pharmacological treatments for CP, and participants' satisfaction with CP treatments. All the statistical analyses were performed using SPSS software, version 18. RESULTS: In the current study, 6.95% of the 1,050 subjects willing to participate in the study had CP for more than six months. According to the results, 54% of the subjects with CP used analgesics, mostly non-steroidal anti-inflammatory drugs (NSAIDs) and narcotic analgesics. Besides, 37% of the subjects used other pain relief methods such as traditional medicine and acupuncture. The results also showed an acceptable rate of satisfaction with treatments. CONCLUSIONS: The number of subjects with CP proved it as a prevalent problem in the study population. Furthermore, characteristics and associations of those experiencing CP demonstrated that it might have significant negative health and psychosocial outcomes in this group. The problem was found significant enough to consider special health programs to prevent and manage CP in urban population of Shiraz.