Device Evaluation, Treatment, and Explantation Recommendations (DETER): Review and Best Practices for Managing Neuromodulation Device Infections.

Retrospective cohort study of a prospectively collected multi-center database of adult spinal deformity (ASD) patients. We hypothesized that patients undergoing ASD surgery with and without previous spinal cord stimulators (SCS)/ intrathecal medication pumps (ITP) would exhibit increased complication rates but comparable improvement in health-related quality of life. ASD patients sometimes seek pain management with SCS or ITP before spinal deformity correction. Few studies have examined outcomes in this patient population. Patients undergoing ASD surgery and eligible for 2-year follow-up were included. Preoperative radiographs were reviewed for the presence of SCS/ITP. Outcomes included complications, Oswestry Disability Index (ODI), Short Form-36 Mental Component Score, and SRS-22r. Propensity score matching was utilized. In total, of 1034 eligible ASD patients, a propensity score-matched cohort of 60 patients (30 with SCS/ITP, 30 controls) was developed. SCS/ITP were removed intraoperatively in most patients (56.7%, n = 17). The overall complication rate was 80.0% versus 76.7% for SCS/ITP versus control (P > 0.2), with similarly nonsignificant differences for intraoperative and infection complications (all P > 0.2). ODI was significantly higher among patients with SCS/ITP at baseline (59.2 vs. 47.6, P = 0.0057) and at 2-year follow-up (44.4 vs. 27.7, P = 0.0295). The magnitude of improvement, however, did not significantly differ (P = 0.45). Similar results were observed for SRS-22r pain domain. Satisfaction did not differ between groups at either baseline or follow-up (P > 0.2). No significant difference was observed in the proportion of patients with SCS/ITP versus control reaching minimal clinically important difference in ODI (47.6% vs. 60.9%, P = 0.38). Narcotic usage was more common among patients with SCS/ITP at both baseline and follow-up (P < 0.05). ASD patients undergoing surgery with SCS/ITP exhibited worse preoperative and postoperative ODI and SRS-22r pain domain; however, the mean improvement in outcome scores was not significantly different from patients without stimulators or pumps. No significant differences in complications were observed between patients with versus without SCS/ITP.Level of Evidence: 3.

Rationale:Transverse myelitis (TM) is a spinal cord inflammatory myelopathy that causes motor/sensory loss and urinary retention below the level of the affected spinal cord. Although a few case reports have described the control of neuropathic pain in patients with TM via spinal cord stimulation, no documented case regarding the control of severe allodynia following TM via intrathecal pump has been described.Patient concerns:A 37-year-old woman was referred to a pain clinic for severe intractable pain below the T5 level followed by Sjögren's syndrome-induced TM.Diagnoses:A neurological examination revealed paresthesia and allodynia below the T5 level. The sensory evaluation was limited by extreme pain and jerking movements. The muscle strength of both lower limbs was grade 3.Interventions:Intrathecal pump was inserted into the left lower abdomen. Catheter tip was placed at the midline of the T8 level.Outcomes:The numeric rating scale (NRS) for pain score decreased from 10 to 5. Functional Independence Measure score increased from 67 before implantation to 92 at the time of discharge, while the patient's Barthel score increased from 31 to 46.Lessons:Neuropathic pain due to Sjögren's syndrome-related TM could be controlled effectively using the intrathecal morphine pump.

To present our experience with 4 para-athletes implanted with intrathecal baclofen pump and spinal cord stimulation, detailing their management and the potential complications these patients may face. For spinal cord stimulation, data collected included stimulation level, surgical complications, and pain scale assessment before the procedure and at 3-mo follow-up. For intrathecal baclofen, data collected included catheter level, surgical complications, baclofen concentration and dosage, and Modified Ashworth Scale. The sports practiced by the patients include sitting volleyball, shooting, handcycling, and table tennis. Concerning patients implanted with spinal cord stimulation, the first patient showed benefits on her phantom limb pain allowing her to resume training while the second patient presented an electrode fracture. Patients receiving intrathecal baclofen improved their spasticity. One of the patients required only a continuous infusion, while the other needed a bolus infusion adapted to training hours. The use of spinal cord stimulation and intrathecal baclofen in para-sports is not contraindicated. Only the use of intrathecal morphine requires a therapeutic use exemption. Spinal cord stimulation and intrathecal baclofen require special monitoring, considering the needs of para-athletes and the particularities of the sport they practice. Further studies will be needed to assess the sporting performance of patients implanted with spinal cord stimulation or intrathecal infusion pumps.

Objective: Spinal cord stimulation (SCS) is one of the widely used procedures for the treatment of complex regional pain syndrome (CRPS). However, complete pain relief is rarely achieved, and the SCS effect diminishes over time. Recently intrathecal baclofen (ITB) therapy is reported to be a modality for treating fixed dystonia related to CRPS. Other reports have suggested that ITB therapy can enhance the effect of SCS in patients with neuropathic pain. We report the effectiveness of combined SCS and ITB therapy, focusing on the role of ITB therapy as an adjunctive therapy for controlling symptoms of advanced CRPS. Methods: Five affected extremities of 4 patients with CRPS (2 male; mean age, 32.5 years) refractory to conservative treatment were evaluated retrospectively. Three patients underwent SCS implantation first, with ITB pumps being implanted a few years later. Bolus ITB injection was administered under temporary percutaneous SCS in 1 patient. Pain intensity was evaluated using the visual analogue scale (VAS) before and after ITB administration. Results: Pain relief of more than 50% was observed in the upper extremity of 1 patient and one of more than 30% was observed in 2 patients. The mean pain reduction rate in all 4 patients was 28.9% before and 43.8% after treatment. All patients, including those without any improvements in VAS score, showed decreased postural abnormalities after combined SCS and ITB therapy. Improvement in postural abnormalities, such as fixed dystonia or paroxysmal tremor-like movements, resulted in overall pain relief by reducing pain fluctuations. Conclusions: Combined SCS and ITB neuromodulation decreases pain intensity in refractory CRPS cases or improves associated abnormal dystonic posture and movement disorders and reduces pain fluctuations.

Retrospective cohort study. To determine risks associated with posterior lumbar arthrodesis after spinal cord stimulator (SCS) and intrathecal pain pump (IPP) insertion. SCS and IPPs aid in the management of chronic back and radicular pain. Little is known regarding the risks of subsequent fusion with these devices in place. The PearlDiver Mariner database was queried for spinal fusion between 2010 and 2020. Study groups were created for indwelling SCS or IPP and matched to a separate cohort without SCS or IPP. Subgroups were created for those who had their device removed and those who retained their device at the time of surgery. Complications up to 2 years postoperatively were reviewed and confounding variables were controlled using multivariable logistic regression. Four thousand five hundred three patients had an indwelling SCS/IPP and underwent posterior lumbar fusion. Compared with patients without history of an SCS/IPP, patients undergoing a lumbar fusion with an SCS/IPP which was removed or retained had higher rates of revision surgery at 1 year [7.3% vs. 5.0%, odds ratio (OR) =1.48, P <0.001] and 2 year (10.8% vs. 7.0%, OR =1.59, P <0.001). For all time intervals, there were higher odds of instrumentation failure (2y: OR =1.65, P <0.001), and pulmonary complications (2y: OR =1.18, P <0.001). At 2 years, there were higher odds of surgical site complications (OR 1.15, P =0.02) and urinary complications (OR=1.07, P =0.04). There were no differences in complications up to 2 years postoperatively in patients with an SCS/IPP who had their devices retained or removed ( P >0.05). Patients with a history of spinal cord stimulators and intrathecal pain pumps are at increased risk of mechanical complications and revision fusion compared with patients without these devices. Patients with an SCS or IPP have similar rates of complications during lumbar fusion whether the device is removed or retained.

Spinal cord stimulation (SCS) is an effective approach to managing chronic, intractable pain. However, even when the designs of SCS devices are compatible with magnetic resonance imaging (MRI), migration and the fracture or wire breakage of epidural leads can result in increased lead impedance and a requirement that the devices be explanted before safe imaging can take place. Selected SCS systems are designed with other technical features. Specifically, lead shielding (lead wires are encased in a matrix-like tantalum shield) serves to dissipate radiofrequency energy along the lead to reduce the risk of thermal tissue damage during MRI scans- even when lead impedance is out of range. To compare the rates of MRI and SCS device explantation in patients who had SCS systems with lead-shielding SCS (LS-SCS) to those who had systems without lead-shielding SCS (non-LS-SCS), and to understand the clinical implications of those findings. A retrospective study of noninterventional administrative-claims data. The Center for Medicare and Medicaid Services (CMS) Research Identifiable Files (RIF). Any patient with continuous coverage who underwent implantation of an SCS system within the year 2018 and had no prior history of SCS, a failed neuromodulation device, or peripheral nerve stimulation was eligible. The analysis time frame included a one-year, pre-implantation baseline period and a 3-year post-implantation follow-up period. Claims were analyzed for post-implantation MRI use, SCS-system explantation, and post-MRI diagnoses. The measurements consisted of the time until the first MRI, the anatomic location of the MRI, the post-MRI diagnosis, the incidence of SCS explantation, and the time from explantation to MRI. Of the 27,636 patients (59% female, 72% aged 65 years or older, and 91% white) who met the eligibility criteria, 18% were implanted with LS-SCS, and 82% were implanted with non-LS-SCS devices between Jan 1 and Dec 31, 2018. Significantly more patients (37.6%) with LS-SCS devices underwent MRI than did patients with non-LS-SCS devices (24.3%; 54.7% relative difference, P = 0.0007), and significantly fewer LS-SCS patients underwent explantation followed by MRI than did patients in the non-LS-SCS cohort (18.9% vs. 28.8%, P < 0.001). Approximately half of the MRI procedures were for spinal imaging in both cohorts, and the most common new diagnoses in the 30 days after the MRI included osteoarthritis, non-VCF injury/fractures, and cancer. Bivariate survival analysis showed that patients with LS-SCS devices had a significantly higher probability of undergoing MRI sooner than patients with non-LS-SCS devices (71.6% higher in adjusted hazard analysis; P < 0.001). This study was a retrospective claims analysis, subject to potential inconsistencies in data quality and completeness, coding, availability of variables for study, and an inability to distinguish correlation from causation. Patients with LS-SCS devices utilized MRI at meaningfully higher rates than patients treated with non-LS-SCS, and nearly one-quarter of SCS-device explants were potentially associated with facilitating the safe use of MRI. The study results suggest that MRI compatibility has potential repercussions that should be considered in the selection of an SCS system.

The use of neuromodulation, specifically spinal cord stimulator, has gained popularity in the management of chronic pain syndromes. Some indications for spinal cord stimulator placement include chronic pain arising from complex regional pain syndrome (CRPS), neuropathy, and post-laminectomy syndrome. With placement of spinal cord stimulator, there have been poorly described cases of post-operative thoracic radiculopathy as a potential complication. This case report describes a patient with prolonged severe thoracic radiculopathy after undergoing spinal cord stimulator paddle lead placement. The patient is a 52 years old female with a history of worsening low back and leg pain not relieved by conservative measures and back surgeries. She underwent successful percutaneous SCS trial with greater than 80% relief of her symptoms; with subsequent implantation of SCS, paddle lead. In the immediate post-operative period, the patient reported good relief of leg pain with spinal cord stimulator turned on. However, she complained of severe, achy bandlike thoracic and abdominal pain. Of note, there were no intraoperative events. Her pain was minimally relieved with medication management. All laboratory work, abdominal and chest radiographs as well endoscopy was negative. With good relief of leg pain with SCS, she declined removal of the paddle lead. There are a few case studies that have described thoracic radiculopathy after spinal cord stimulator placement. In those cases, pain gradually improved within a short duration; and or after removal of the device. This particular patient had prolonged steady 9-10/10 abdominal pain that was not amenable to conservative treatment. Although a rare phenomenon, it is important to know that persistent abdominal pain can be a result of thoracic neurological injury during SCS lead placement.

Course of treatment and rate of successful salvage following the diagnosis of deep infection in patients treated for pilon fractures (AO/OTA: 43)

Despite rapid development and expansion of neuromodulation technologies, knowledge about device and/or therapy durability remains limited. The aim of this study was to evaluate the long-term rate of hardware and therapeutic failure of implanted devices for several neuromodulation therapies. The authors performed a retrospective analysis of patients' device and therapy survival data (Kaplan-Meier survival analysis) for deep brain stimulation (DBS), vagus nerve stimulation (VNS), and spinal cord stimulation (SCS) at a single institution (years 1994-2015). During the study period, 450 patients underwent DBS, 383 VNS, and 128 SCS. For DBS, the 5- and 10-year initial device survival was 87% and 73%, respectively, and therapy survival was 96% and 91%, respectively. For VNS, the 5- and 10-year initial device survival was 90% and 70%, respectively, and therapy survival was 99% and 97%, respectively. For SCS, the 5- and 10-year initial device survival was 50% and 34%, respectively, and therapy survival was 74% and 56%, respectively. The average initial device survival for DBS, VNS, and SCS was 14 years, 14 years, and 8 years while mean therapy survival was 18 years, 18 years, and 12.5 years, respectively. The authors report, for the first time, comparative device and therapy survival rates out to 15 years for large cohorts of DBS, VNS, and SCS patients. Their results demonstrate higher device and therapy survival rates for DBS and VNS than for SCS. Hardware failures were more common among SCS patients, which may have played a role in the discontinuation of therapy. Higher therapy survival than device survival across all modalities indicates continued therapeutic benefit beyond initial device failures, which is important to emphasize when counseling patients.

This case report presents an instance of an S-Series™ slim paddle lead fracturing during extraction, highlighting potential risks associated with the removal of this lead. A 47-year-old male with complex regional pain syndrome type 2, unresponsive to pharmacotherapy, had undergone the implantation of two spinal cord stimulator (SCS) leads, an Octrode™ cylindrical and an S-series™ slim paddle, using the Epiducer™ system (St Jude Medical) 9 years earlier, with a subsequent intrathecal baclofen pump installed 1 year after SCS. Initially, these interventions stabilized the patient's pain symptoms. However, the diminishing effectiveness of SCS, coupled with a decrease in battery life and increased opioid consumption, necessitated recent surgical procedures. These included the removal and replacement of the implantable pulse generator (IPG) and leads to improve pain management and ensure MRI compatibility. During the removal of the S-series™ slim paddle type lead, complications arose, leading to the retention of an electrode fragment, which necessitated abandoning the replacement of both the IPG and lead. Post-surgical assessments revealed no new neurological impairments, and imaging studies confirmed the stable position of the retained fragment. The patient was discharged with a continued comprehensive pain management plan. This case highlights the challenges and risks of percutaneous removal of slim paddle type leads, emphasizing the need for careful procedural planning and consideration of surgical options to avoid complications. Further research is needed to evaluate the long-term durability and removal risks of various SCS lead types.

Radiofrequency ablation (RFA) is a treatment modality used in interventional pain management to treat several conditions including chronic neck or back pain, sacroiliac joint pain, major joint pain, and pain from sites that can be isolated to a sensory nerve amenable to RFA. The goals of such procedures are to reduce pain, improve function, delay need for surgical intervention, and reduce pain medication consumption. As applications for RFA expand through novel techniques and nerve targets, there is concern with how RFA may impact patients with implanted medical devices. Specifically, the electrical currents used in RFA produce electromagnetic interference, which can result in unintentional energy transfer to implanted devices. This may also interfere with device function or cause damage to the device itself. As the number of patients with implanted devices increases, it is imperative to establish guidelines for the management of implanted devices during RFA procedures. This review aims to establish guidelines to assist physicians in the preoperative, intraoperative, and postoperative management of implanted devices in patients undergoing procedures using radiofrequency energy. Here, we provide physicians with background knowledge and a summary of current evidence to allow safe utilization of RFA treatment in patients with implanted devices such as cardiac implantable electronic devices, spinal cord stimulators, intrathecal pumps, and deep brain stimulators. While these guidelines are intended to be comprehensive, each patient should be assessed on an individual basis to optimize outcomes.

INTRODUCTION: Spinal cord stimulators (SCS) are commonly implanted via a laminotomy or laminectomy. Revision surgery may be necessary in instances of hardware failure or loss of efficacy. It is uncommon for leads to have been initially misplaced in a suboptimal position, and revision in these cases necessitates additional dissection for appropriate repositioning. Accordingly, there is concern for a potentially higher risk of associated complications, including dural tear, cerebrospinal fluid (CSF) leak, epidural hematoma, and neurological injury. It is well-documented that revision spinal surgery can be associated with worse outcomes. METHODS: Patients who underwent SCS paddle replacement for misplaced paddles between 2021 and 2023 were identified. Medical charts were reviewed for demographic data, operative details, and incidence of complications. RESULTS: Sixteen patients underwent thoracic SCS paddle revision and replacement. The mean age was 59.6±12.6 years, with 11 females and 5 males. Misplaced paddles were too lateral (n=12), too high (n=2), or incompletely within the epidural space (n=2). The mean duration from initial implantation to revision surgery was 44.8±47.5 months. The mean operative duration was 126.1±26.9 minutes, and all patients required a “skip” laminectomy or laminotomy. No complications were encountered. The mean length of follow-up was 18.4±7.3 months. Mean preoperative pain intensity was 7.9±1.5, and at last follow-up was 3.6±1.7 (p&lt;0.001). All but one patient continued to use their device in follow-up. CONCLUSIONS: The revision and replacement of misplaced paddle SCS electrodes is a feasible and durable revision strategy, even in long-term implants with extensive scarring.

Spinal cord stimulation (SCS) consists of the implantation of neuromodulatory devices in the spinal cord to treat refractory neuropathic pain. Although SCS technology has been proven of immense clinical benefit, complications remain including refractory pain, infection risk, and electrode migration or displacement. Till date, there are minimal reports of allergic side effects following SCS implantation. In the first case, a 36-year-old male with chronic axial and radicular neuropathic pain in underwent implantation of an open paddle lead and generator. Within 1-3 h of activating the SCS, he developed diffuse raised erythematous hives. Over time, the SCS had immense clinical benefit for his pain reduction; however, he continued to experience recurrent hives and various other allergic reactions including facial flushing and photosensitivity. Four years later, he ultimately opted to retain the device for its clinical pain benefits. In the second case, a 35-year-old female with acute, intractable bilateral occipital neuralgia and a past medical history of Type 1 Chiari Malformation status-post-posterior fossa decompression underwent implantation of an occipital nerve stimulator (ONS). At 1-month follow-up, she began to experience pruritus across the back of her head and along the subcutaneous course of the lead. At 8 months, she continued to experience persistent symptoms, ultimately opting for device removal. Although allergic reactions to implanted neurostimulation systems are rare, and mechanisms not completely understood, existing studies posit multiple theories surrounding the pathophysiology of allergic reactions to these devices, such as delayed hypersensitivity reactions or contact dermatitis. Further research is needed to elucidate the cutaneous and immunologic side effects of SCS and ONS devices.

The use of spinal cord stimulation (SCS) devices to treat chronic, refractory neuropathic pain continues to expand in application. While device-related complications have been well described, inflammatory reactions to the components of these devices remain underreported. In contrast, hypersensitivity reactions associated with other implanted therapies, such as endovascular and cardiac rhythm devices, have been detailed. The purpose of this case series is to describe the clinical presentation and course of inflammatory reactions as well as the histology of these reactions. All patients required removal of the entire device after developing inflammatory reactions over a time course of 1–3 months. Two patients developed a foreign body reaction in the lead insertion wound as well as at the implantable pulse generator site, with histology positive for giant cells. One patient developed an inflammatory dermatitis on the flank and abdomen that resolved with topical hydrocortisone. “In vivo” testing with a lead extension fragment placed in the buttock resulted in a negative reaction followed by successful reimplantation of an SCS device. Inflammatory reactions to SCS devices can manifest as contact dermatitis, granuloma formation, or foreign body reactions with giant cell formation. Tissue diagnosis is essential, and is helpful to differentiate an inflammatory reaction from infection. The role of skin patch testing for 96 hours may not be suited to detect inflammatory giant cell reactions that manifest several weeks post implantation.

Lower urinary tract (LUT) dysfunction arising from injury and disease remain a clinical challenge due to unavailability of pharmacological treatments. Neuromodulation devices developed to tackle these disorders, such as sacral stimulators, are non‐selective for a single nerve with numerous off‐target effects while also stimulating the afferent and efferent population in a nerve. Here, we investigate whether epidural spinal cord stimulation (SCS) and microstimulation of dorsal root ganglion (DRG) through penetrating microarrays, can selectively activate and control reflexes relevant to LUT function. We demonstrate that custom high‐density epidural arrays and Utah arrays in the DRG can selectively access pelvic and pudendal innervation, and can modulate LUT function.To determine the effects of stimulation on peripheral nerve recruitment, α‐chloralose anesthetized male cats (SCS: n=6, DRG: n=4) were instrumented with nerve cuffs on the pelvic nerve as well as the pudendal nerve and its branches. High‐density epidural electrodes were placed corresponding to the lumbosacral (L6 and L7 laminae) and sacral (S1 laminae) spinous processes. In separate DRG experiments, 32‐channel high‐density penetrating Utah arrays were implanted in the S1, S2 and S3 DRG. We stimulated epidurally and within the DRG while recording compound action potentials in nerve cuffs. Functional effects of stimulation were measured using intravesical and transurethral catheters to measure bladder and urethral pressures respectively across various stimulus amplitudes and frequencies.All the instrumented nerves could be selectively recruited with both DRG and SCS stimulation, although not every nerve was selectivity recruited in every animal. The stimulation amplitude to evoke functional responses was higher (SCS: 600–1000 μA, DRG: 20–45 μA) than the minimum threshold to evoke antidromic activity in nerve cuffs. SCS and DRG stimulation both evoked bladder parasympathetic contractions similar to direct stimulation of the pelvic nerve. In several trials, stimulation through the same epidural electrode during cystometry, low frequency (3 Hz) stimulation evoked a continence reflex resulting in a suppression of detrusor activity, while high frequency (33 Hz) stimulation evoked a micturition reflex resulting in high intravesical pressures. Isovolumetric and filling cystometry was performed to confirm the action of these reflexes.SCS and DRG stimulation can selectively activate pelvic and pudendal innervation, and elicit micturition and continence reflexes.Support or Funding InformationR01 NS088184 and OT2OD024908. Craig H. Neilsen Foundation Award 476681