Spinal Cord Stimulator Infection: Approach to Diagnosis, Management, and Prevention

ASRA Pain Medicine consensus practice infection control guidelines for regional anesthesia and pain medicine

BACKGROUND

To provide recommendations on risk mitigation, diagnosis and treatment of infectious complications associated with the practice of regional anesthesia, acute and chronic pain management.

METHODS

Following board approval, in 2020 the American Society of Regional Anesthesia and Pain Medicine (ASRA Pain Medicine) commissioned evidence-based guidelines for best practices for infection control. More than 80 research questions were developed and literature searches undertaken by assigned working groups comprising four to five members. Modified US Preventive Services Task Force criteria were used to determine levels of evidence and certainty. Using a modified Delphi method, >50% agreement was needed to accept a recommendation for author review, and >75% agreement for a recommendation to be accepted. The ASRA Pain Medicine Board of Directors reviewed and approved the final guidelines.

RESULTS

After documenting the incidence and infectious complications associated with regional anesthesia and interventional pain procedures including implanted devices, we made recommendations regarding the role of the anesthesiologist and pain physician in infection control, preoperative patient risk factors and management, sterile technique, equipment use and maintenance, healthcare setting (office, hospital, operating room), surgical technique, postoperative risk reduction, and infection symptoms, diagnosis, and treatment. Consensus recommendations were based on risks associated with different settings and procedures, and keeping in mind each patient's unique characteristics.

CONCLUSIONS

The recommendations are intended to be multidisciplinary guidelines for clinical care and clinical decision-making in the regional anesthesia and chronic interventional pain practice. The issues addressed are constantly evolving, therefore, consistent updating will be required.

Biofilm-mediated antibiotic tolerance in Staphylococcus aureus from spinal cord stimulation device-related infections

Staphylococcus aureus is a predominant cause of infections in individuals with spinal cord stimulation (SCS) devices. Biofilm formation complicates these infections, commonly requiring both surgical and antibiotic treatments. This study explored the biofilm matrix composition and antimicrobial susceptibility of planktonic and biofilm-growing S. aureus isolates from individuals with SCS-related infections. Whole-genome sequencing (WGS) examined genotypes, virulome, resistome, and the pan-genome structure. The study also analyzed biofilm matrix composition, early surface adhesion, hemolytic activity, and antibiotic-susceptibility testing. WGS revealed genetic diversity among isolates. One isolate, though oxacillin susceptible, contained the mecA gene. The median number of virulence factor genes per isolate was 58. All isolates harbored the biofilm-related icaA/D genes. When assessing phenotypic characteristics, all strains demonstrated the ability to form biofilms in vitro. The antimicrobial susceptibility profile indicated that oxacillin, rifampin, and teicoplanin showed the highest efficacy against S. aureus biofilm. Conversely, high biofilm tolerance was observed for vancomycin, trimethoprim/sulfamethoxazole, and levofloxacin. These findings suggest that S. aureus isolates are highly virulent and produce robust biofilms. In cases of suspected biofilm infections caused by S. aureus, vancomycin should not be the primary choice due to its low activity against biofilm. Instead, oxacillin, rifampin, and teicoplanin appear to be more effective options to manage SCS infections.IMPORTANCESCS devices are increasingly used to manage chronic pain, but infections associated with these devices, particularly those caused by Staphylococcus aureus, present significant clinical challenges. These infections are often complicated by biofilm formation, which protects bacteria from immune responses and antibiotic treatments, making them difficult to eradicate. Understanding the genetic diversity, virulence, and biofilm characteristics of S. aureus isolates from SCS infections is critical to improving treatment strategies. Our study highlights the need to reconsider commonly used antibiotics like vancomycin, which shows reduced activity against biofilm-growing cells. Identifying more effective alternatives, such as oxacillin, rifampin, and teicoplanin, provides valuable insight for clinicians when managing biofilm-related S. aureus infections in patients with SCS implants. This research contributes to the growing evidence that biofilm formation is crucial in treating device-related infections, emphasizing the importance of tailoring antimicrobial strategies to the biofilm phenotype.

The Neurostimulation Appropriateness Consensus Committee (NACC)®: Recommendations for the Mitigation of Complications of Neurostimulation

INTRODUCTION

The International Neuromodulation Society convened a multispecialty group of physicians based on expertise and international representation to establish evidence-based guidance on the mitigation of neuromodulation complications. This Neurostimulation Appropriateness Consensus Committee (NACC)® project intends to update evidence-based guidance and offer expert opinion that will improve efficacy and safety.

MATERIALS AND METHODS

Authors were chosen on the basis of their clinical expertise, familiarity with the peer-reviewed literature, research productivity, and contributions to the neuromodulation literature. Section leaders supervised literature searches of MEDLINE, BioMed Central, Current Contents Connect, Embase, International Pharmaceutical Abstracts, Web of Science, Google Scholar, and PubMed from 2017 (when NACC last published guidelines) to October 2023. Identified studies were graded using the United States Preventive Services Task Force criteria for evidence and certainty of net benefit. Recommendations are based on the strength of evidence or consensus when evidence was scant.

RESULTS

The NACC examined the published literature and established evidence- and consensus-based recommendations to guide best practices. Additional guidance will occur as new evidence is developed in future iterations of this process.

CONCLUSIONS

The NACC recommends best practices regarding the mitigation of complications associated with neurostimulation to improve safety and efficacy. The evidence- and consensus-based recommendations should be used as a guide to assist decision-making when clinically appropriate.

Epidural spread of surgical site infection from spinal cord stimulation trial

We present a case of deep surgical site infection (SSI) at a spinal cord stimulator (SCS) trial implantation site, resulting from an allergic reaction to an unknown agent. A 38-year-old female with complex regional pain syndrome began an SCS trial, noting 100% pain relief for 5 days. Fluid drainage from the surgical site was reported on POD6 and trial leads were removed the following day. The patient was hospitalized with sepsis. Blood cultures revealed Staphylococcus aureus. MRIs showed skin breakdown and cellulitis of the paraspinal musculature extending into the epidural space. The patient was maintained with antibiotics and rigorous wound care for 9 days and the surgical site infection resolved. The patient proceeded to SCS implantation, and reported good pain relief with the implanted device.

Complications of Spinal Cord Stimulators-A Comprehensive Review Article

PURPOSE OF REVIEW

Spinal cord stimulation has been increasing in influence as an option to regulate pain, especially in the chronic pain patient population. However, even with the numerous changes made to this technology since its inception, it is still prone to various complications such as hardware issues, neurological injury/epidural hematoma, infections, and other biological concerns. The purpose of this article is to thoroughly review and evaluate literature pertaining to the complications associated with percutaneous spinal cord stimulation.

RECENT FINDINGS

Lead migration is generally the most common complication of percutaneous spinal cord stimulation; however, recent utilization of various anchoring techniques has been discussed and experienced clinical success in decreasing the prevalence of lead migration and lead fractures. With newer high-frequency systems gaining traction to improve pain management and decrease complications as compared to traditional systems, rechargeable implantable pulse generators have been the preferred power source. However, recent findings may suggest that these rechargeable implantable pulse generators do not significantly increase battery life as much as was proposed. Intraoperative neuromonitoring has seen success in mitigating neurological injury postoperatively and may see more usage in the future through more testing. Though the occurrence of infection and biological complications, including dural puncture and skin erosion, has been less frequent over time, they should still be treated in accordance with established protocols. While many complications can arise following percutaneous spinal cord stimulator implantation, the procedure is less invasive than open implantation and has seen largely positive patient feedback. Hardware complications, the more common issues that can occur, rarely indicate a serious risk and can generally be remedied through reoperation. However, less common cases such as neurological injury, infections, and biological complications require prompt diagnosis to improve the condition of the patient and prevent significant damage.

Analysis of reasons for medical malpractice litigation due to spinal cord stimulator

Study design

Retrospective cohort study.

Introduction

Malpractice claims analysis is performed by several specialties to improve quality of patient care and to identify areas where physicians can improve their practice to mitigate the incidence of committing malpractice. The Food and Drug Administration has flagged over 80,000 injuries caused by spinal cord stimulator (SCS), making them the 3rd most flagged medical device. This study analyzed malpractice claims due to SCS by querying two legal databases widely used in medicolegal research.

Methods

Westlaw Edge and VerdictSearch were queried for malpractice cases filed between the years 2000 and 2022 using the keywords "spinal cord stimulator." Case inclusion criteria was defined as a plaintiff's basis of litigation resting on a claim of medical malpractice due to SCS. Additional data collected included date of case hearing, plaintiff sex and age, defendant specialty, verdict ruling, location of the filed claim, payment or settlement amount, and sustained injuries.

Result

Of the 1773 reviewed cases, 45 cases were included and categorized as battery or implantable pulse generator malfunction (35.56 %), lead complications (28.89 %), surgical complications (20.00 %), and miscellaneous (15.56 %). Four (8.89 %) cases resulted in settlement, 11 (24.44 %) in a plaintiff verdict, and 30 (68.00 %) resulted in a defendant verdict. Claims filed due to infection related to SCS were more likely to result in a defendant verdict (p = .047), whereas claims filed due to neurological deficit were more likely to result in a plaintiff verdict (p = .020). The average settlement amount for the 4 cases is $1,975,309.61.

Conclusion

Our findings suggest obtaining adequate neuroimaging preoperatively with MRIs, disclosing neurological risks specifically paralysis on informed consent, and evaluating radiography intraoperative and postoperatively with anterior-posterior (AP) and lateral x-ray films to ensure proper SCS placement are practices that may mitigate malpractice due to SCS. Battery defects and lead complications were the most common grounds for SCS-related malpractice claims.

Rescuing Infected Deep Brain Stimulation Therapies in Severely Affected Patients

(1) Background: Infections in deep brain stimulation (DBS) hardware, while an undesired complication of DBS surgeries, can be effectively addressed. Minor infections are typically treated with wound revision and IV antibiotics. However, when visible hardware infection occurs, most centers opt for complete removal, leaving the patient in a preoperative state and necessitating post-removal care. To avoid the need for such care, a novel technique was developed. (2) Methods: The electrodes are placed at the exact same spot and then led to the contralateral side. new extensions and a new generator contralateral to the infection as well. Subsequently, the infected system is removed. This case series includes six patients. (3) Results: The average duration of DBS system implantation before the second surgery was 272 days. Only one system had to be removed after 18 months due to reoccurring infection; the others remained unaffected. Laboratory alterations and pathogens were identified in only half of the patients. (4) Conclusions: The described surgical technique proves to be safe, well tolerated, and serves as a viable alternative to complete system removal. Importantly, it effectively prevents the need of post-removal care for patients.

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.

Multiphase Spinal Cord Stimulation in Participants With Chronic Back or Leg Pain: Results of the BENEFIT-02 Randomized Clinical Trial

OBJECTIVE

This study aimed to assess the safety and effectiveness of a new charge-distributed multiphase stimulation paradigm during an extended spinal cord stimulation (SCS) trial.

MATERIALS AND METHODS

This prospective, multicenter, randomized, single-blind, feasibility study included participants with chronic low back and/or leg pain and baseline numerical rating scale (NRS) for overall pain intensity ≥6. After a successful commercial SCS trial, participants were randomized to multiphase SCS therapy A (approximately 600-1500 Hz) or B (approximately 300-600 Hz), delivered via an investigational external pulse generator and existing leads during an 11-to-12-day testing period. Primary end points were mean NRS change from baseline to final in-office visit for each multiphase therapy and between therapies. Secondary end points included mean NRS change from end of commercial trial to final study visit and incidence of device-related adverse events (AEs). Additional measures included patient-reported outcomes collected at home through electronic watches and written diaries. Power usage was compared between multiphase and commercial therapies.

RESULTS

A total of 122 participants initiated a commercial trial; 77 were randomized to a multiphase arm, and 65 completed the study. Reductions in mean NRS scores from baseline to final study visit were significant for multiphase therapy A and B (-4.3 and -4.7, respectively; both p < 0.0001). There was no statistically significant difference in mean NRS reduction or percent pain relief between multiphase therapies. In an additional analysis, 63.9% of participants reported greater pain relief with multiphase than with commercial SCS therapy in the at-home setting. On average, multiphase required less power than did commercial devices. One non-serious device-related AE was reported, and no infections occurred during the extended trial.

CONCLUSIONS

Multiphase SCS effectively reduced pain in participants with chronic low back and/or leg pain during a trial, with no unanticipated device-related AEs reported. Future studies should evaluate long-term effectiveness of multiphase stimulation.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the study is NCT03594266.

Latent infection after spinal cord stimulation device implantation for complex regional pain syndrome: A case report

RATIONALE

Spinal cord stimulation (SCS) is one of the invasive treatments of complex regional pain syndrome (CRPS). The positive effect has been observed for several years after implantation. However, infection is a common cause of SCS failure and device removal.

PATIENT CONCERNS

Here we describe a case of latent infection at the implantable generator pocket site 9 years after SCS implantation in a patient with CRPS.

DIAGNOSES

A 52-year-old patient was diagnosed with type 1 CRPS. The right foot pain was intractable with standard treatments. SCS implantation was performed and SCS worked well without complication. Nine years later, the patient revisited due to pain, tenderness, and redness at the abdominal wall for 2 weeks. The right foot pain was maintained with NRS 4 for 8 years, and the stimulation stopped 1 year back. SCS infection was diagnosed.

INTERVENTIONS

The patient underwent SCS removal surgery.

OUTCOMES

All SCS devices were removed successfully. The patient was discharged without any complications.

CONCLUSIONS

While uncommon, infection after SCS implantation can occur even 9 years later. Immediate diagnosis, proper antibiotics, and surgical removal could be needed to prevent further spread of infection and better prognosis.

Spontaneous Proteus mirabilis Meningitis in Adults Requiring an Extended Antibiotic Course: Case Report and Literature Review

Most cases of gram-negative bacillary meningitis occur in neonates and infants. Meningitis in adults caused by Proteus mirabilis has been reported rarely. Evidence-based guidelines for the treatment of adult patients with gram-negative bacillus meningitis are scarce. The optimal duration of antibiotic therapy for these patients is an unanswered question in the medical literature. This article outlines a case of community-acquired meningitis caused by P. mirabilis in an adult patient who required an extended antimicrobial treatment, after failing to a three-week antibiotic regime. Our patient, a 66-year-old man with a history of neurogenic bladder, remote spinal cord trauma, and recurrent urinary tract infections presented to the emergency department reporting a two-day history of severe headache, fever, and confusion. Cerebrospinal fluid (CSF) revealed significant neutrophil-predominant pleocytosis, low glucose level, and elevated protein level. CSF culture grew few pan-susceptible P. mirabilis. The patient initially completed 21 days of ceftriaxone guided by susceptibility testing. Nine days after finishing antibiotic therapy, the patient was readmitted with recurrent headache, fever, and neck rigidity. A new CSF study again revealed pleocytosis, elevated polymorphonuclear cells, low glucose level, and elevated protein level, but with a negative CSF culture. The patient became afebrile, and his symptoms improved after two days of ceftriaxone. He completed an additional six-week regime of ceftriaxone. On the one-month follow-up visit, the patient remained afebrile, with no recurrent symptoms. Spontaneous community-acquired P. mirabilis meningitis is rare among adult patients. Experiences in the treatment of gram-negative bacillus meningitis in adults must be shared with the scientific community to build up a better understanding of this condition. In the context of this case, sterilization of the CSF, extended antibiotic therapy, and a close post-treatment follow-up are crucial for treating this life-threatening condition.

The Use of Salvage Procedures for Wound Complications in Neuromodulation

OBJECTIVE

Wound complications are a prevalent concern for neuromodulation procedures. While removal of the device was recommended, attempts to salvage expensive hardware have become commonplace. We examine our management in wound issues to aid in providing guidance for these situations.

METHODS

We identified 40 patients over an 8-year period in a large neuromodulation practice, who underwent washout or partial salvage of hardware. We examined the efficacy of washout and partial explants on the ability to salvage the implants. Covariates including age, sex, body mass index, smoking status, anticoagulation, and device type were considered.

RESULTS

There were 29 washouts and 10 partial hardware removal cases. Washouts were successful in 15/29 cases (51.7%), partial hardware removal was successful in 2/10 cases (20%), and removal with replacement was not successful (0 of 1). Washouts tended to be more successful than partial removal procedures (P = 0.08). In cases of successful washout, the average duration between infectious symptoms and washout was 7.27 ± 2.19 days. None of the demographic variables were associated with increased likelihood of washout failure.

CONCLUSIONS

Our results demonstrate a higher rate of washout failure in those who underwent partial device removal and in the presence of purulence at the surgical site. Further investigation must be conducted to determine the instances in which hardware removal is indicated to prevent failure or removal due to infection. Identification of these parameters will optimize therapeutic benefit and long-term financial impact.

Identifying Predictors for Early Percutaneous Spinal Cord Stimulator Explant at One and Two Years: A Retrospective Database Analysis

OBJECTIVES

Placement of percutaneous spinal cord stimulator (SCS) implant has become a therapeutic option for various chronic pain conditions; however, early surgical explant still occurs. Unfortunately, evidence regarding the incidence of early surgical explant, and patient-specific factors and comorbidities associated with such, is limited and mixed. The objective of this retrospective analysis was to elucidate the incidence and predictors of percutaneous SCS explant within the first two years of device placement.

MATERIALS AND METHODS

The PearlDiver-Mariner Patient Record Database of all payer claims was used to identify patients who underwent percutaneous lead SCS implant (leads and generator) with subsequent explant within two years of initial device implant. The primary outcome was to determine the incidence of SCS explant within the first two years of device placement. Secondary outcomes included evaluating the effects of several patient-specific comorbidities on explant rates using univariate regression analysis.

RESULTS

Across the database, a total of 52,070 patients who underwent percutaneous lead SCS implant were included, of whom 3104 (5.96%) had SCS explant within the first two years. Most explants occurred within the first-year time interval at 72.8% (2260 patients), whereas only 27.2% (844 patients) had SCS explant between years one and two. At the one-year time interval, covariates associated with an increased odds ratio (OR) (95% CI) of SCS explant were 1) depression (1.39 [1.26, 1.52]), 2) chronic preoperative (1.27 [1.16, 1.39]) or postoperative (1.23 [1,13, 1.36]) opioid use, 3) cannabis abuse (1.58 [1.20, 2.02]), 4) tobacco use (1.13 [1.04, 1.23]), and 5) coagulopathy (1.22 [1.07, 1.38]). In contrast, the OR of explant was lower in patients who were older, men, or had diabetes (complicated or uncomplicated). All associated covariates became nonsignificant after the first year of SCS implant (ie, between the first and second years), and only depression and tobacco use remained as associated factors for device explant.

CONCLUSIONS

Our retrospective analysis highlights that the rate of percutaneous SCS explant appears to considerably decrease after the first year of device implant. Furthermore, this analysis sheds additional insights into patients who may be at risk of early percutaneous SCS explant, especially within the first year of device placement, and underscores the importance of a continued multidimensional/biopsychologic assessment in patients with chronic pain.

Deep Brain Stimulator Device Infection: The Mayo Clinic Rochester Experience

Background

Deep brain stimulator (DBS)-related infection is a recognized complication that may significantly alter the course of DBS therapy. We describe the Mayo Clinic Rochester experience with DBS-related infections.

Methods

This was a retrospective study of all adults (≥18 years old) who underwent DBS-related procedures between 2000 and 2020 at the Mayo Clinic Rochester.

Results

There were 1087 patients who underwent 1896 procedures. Infection occurred in 57/1112 (5%) primary DBS implantations and 16/784 (2%) revision surgeries. The median time to infection (interquartile range) was 2.1 (0.9-6.9) months. The odds of infection were higher with longer operative length (P = .002), higher body mass index (BMI; P = .006), male sex (P = .041), and diabetes mellitus (P = .002). The association between infection and higher BMI (P = .002), male sex (P = .016), and diabetes mellitus (P = .003) remained significant in a subgroup analysis of primary implantations but not revision surgeries. Infection was superficial in 17 (23%) and deep in 56 (77%) cases. Commonly identified pathogens were Staphylococcus aureus (65%), coagulase-negative staphylococci (43%), and Cutibacterium acnes (45%). Three device management approaches were identified: 39 (53%) had complete device explantation, 20 (27%) had surgical intervention with device retention, and 14 (19%) had medical management alone. Treatment failure occurred in 16 (23%) patients. Time-to-event analysis showed fewer treatment failures with complete device explantation (P = .015). Only 1 individual had complications with brain abscess at failure.

Conclusions

Primary DBS implantations had higher rates of infection compared with revision surgeries. Complete device explantation was favored for deep infections. However, device salvage was commonly attempted and is a reasonable approach in select cases given the low rate of complications.

Cervical spinal cord stimulator trial complicated by epidural abscess

Back ground

Spinal cord stimulation (SCS) is a growing interventional treatment modality in patients experiencing intractable pain refractory to conservative treatments. Many patients with chronic low back and leg pain that persists after surgery have found pain relief, and more evidence is suggesting that chronic upper limb and neck pain may respond just as well to this therapy. However, the placement of foreign body, for instance SCS leads, in the epidural space can become the source for deep intra-spinal infection.

Case report

We present a 49-year-old robust male who underwent a temporary cervical SCS trial and was diagnosed with epidural abscess on the day 9 when the leads were pulled. The trial phase was complicated by immediate and prolonged post procedure pain. The diagnosis of epidural abscess was made soon after clinical presentation with no neurological deficits or escalation in pain but new onset fever. He made a complete recovery after extensive laminectomy and antibiotic treatment.

Conclusion

The decision to extend the SCS trial length poses a question of risk versus benefit in regards to potential infectious complications versus pain relief. Continuing antibiotic therapy during a SCS trial phase is a possible strategy but of uncertain benefit.

Categories

Anesthesiology, Pain Management.

A Comprehensive Review of Spinal Cord Stimulator Infections

Spinal cord stimulator (SCS) is approved to treat various pain conditions and is commonly seen in the chronic pain patient population. Due to the nature of the device and its location, infections associated with SCS have a particularly high morbidity. According to post-market data and medical device reports, 87% of patients receiving SCS implants were given perioperative antibiotics as the implantable neurostimulator or receiver pocket serve as the most common sites of infection. The most common antibiotics for surgical prophylaxis given are first-generation cephalosporins (cefalexin, cefazolin) at the time of implantation. If deep infection is suspected, imaging in the form of CT scan should be obtained as physical exam is not always sufficient. For infections involving the epidural space, vertebra, or intervertebral discs, MRI is the preferred imaging modality. If meningitis is suspected, a lumbar puncture is recommended. Positive cultures can help guide antibiotic therapy.

Spinal Cord Stimulation in Special Populations: Best Practices from the American Society of Pain and Neuroscience to Improve Safety and Efficacy

Chronic bleeding disorders, allergy to implants, and chronic infections are all complicating factors when considering neuromodulation therapies. The American Society of Pain and Neuroscience (ASPN) determined a need for clinical guidance in these special patient populations that have increased risk of complications, in order to ensure patient safety and optimal outcomes with device implantation. The purpose of this publication was to review the published literature and explore the unique clinical challenges encountered among several special patient populations with relation to spinal cord stimulation. The executive board of the ASPN appointed a diverse group of well-established physicians to develop best practice guidelines regarding spinal cord stimulation implantation in these special populations. The physicians used the United States Preventive Services Task Force (USPSTF) structured guidelines for grading and level of certainty to make evidence-based recommendations about clinical practice. Where sufficient evidence was lacking to justify a USPSTF ranking, the physicians queried experts in neuromodulation and achieved consensus. These best practices and interventional guideline found the evidence for the use of neuromodulation in specialized patient populations to be relatively modest.

Perioperative Management of Spinal Cord Stimulators and Intrathecal Pain Pumps

Spinal cord stimulators (SCSs) and intrathecal pain pumps (IPPs) are implantable devices used in the management of chronic pain or spasticity. Complications, such as infection, lead migration/failure, cerebrospinal fluid leak, neurologic injury, and other medical complications, can occur after placement and may require surgical intervention. Orthopaedic surgeons may encounter patients with these devices and should have a basic understanding of their function. In addition, they should be aware that patients may have residual stenosis or deformity contributing to their symptoms; thus, spine surgery referral may be indicated. If a patient with a SCS or IPP is undergoing revision spinal surgery, a preoperative discussion regarding retention versus removal of the device is imperative because indications for device retention, revision, and removal are complex. This review summarizes potential complications and intraoperative considerations concerning the proper perioperative management of SCSs/IPPs and will provide evidence-based data regarding management strategies for these devices.

Advances in Epidural Spinal Cord Stimulation to Restore Function after Spinal Cord Injury: History and Systematic Review

Epidural spinal cord stimulation (eSCS) has been recently recognized as a potential therapy for chronic spinal cord injury (SCI). eSCS has been shown to uncover residual pathways within the damaged spinal cord. The purpose of this review is to summarize the key findings to date regarding the use of eSCS in SCI. Searches were carried out using MEDLINE, EMBASE, and Web of Science database and reference lists of the included articles. A combination of medical subject heading terms and keywords was used to find studies investigating the use of eSCS in SCI patients to facilitate volitional movement and to restore autonomic function. The risk of bias was assessed using Risk Of Bias In Non-Randomized Studies of Interventions tool for nonrandomized studies. We were able to include 40 articles that met our eligibility criteria. The studies included a total of 184 patient experiences with incomplete or complete SCI. The majority of the studies used the Medtronic 16 paddle lead. Around half of the studies reported lead placement between T11- L1. We included studies that assessed motor (n = 28), autonomic (n = 13), and other outcomes (n = 10). The majority of the studies reported improvement in outcomes assessed. The wide range of included outcomes demonstrates the effectiveness of eSCS in treating a diverse SCI population. However, the current studies cannot definitively conclude which patients benefit the most from this intervention. Further study in this area is needed to allow improvement of the eSCS technology and allow it to be more widely available for chronic SCI patients.

Evaluating the incidence of spinal cord injury after spinal cord stimulator implant: an updated retrospective review

INTRODUCTION

While spinal cord stimulator implant is an increasingly safe procedure, one of the most feared complications is spinal cord injury. Still, literature regarding its incidence remains highly variable. This retrospective analysis aims to evaluate the incidence of spinal cord injury after spinal cord stimulator implant using a large-scale claims database.

METHODS

The PearlDiver-Mariner database of national all payer claims was used to identify patients who underwent spinal cord stimulator implant (percutaneous or paddle) and developed subsequent spinal cord injury within 45 days. The primary outcome was to determine the overall incidence of spinal cord injury after spinal cord stimulator implant. Secondary outcomes included an evaluation of potential factors associated with developing spinal cord injury using univariable and multivariable regression analysis.

RESULTS

A total of 71,172 patients who underwent a spinal cord stimulator implant were included in the analysis, of which 52,070 underwent percutaneous and 19,102 underwent paddle spinal cord stimulator lead implant. The overall incidence of spinal cord injury after spinal cord stimulator implant (any lead type) was found to be 0.42% (302 patients). The incidence of spinal cord injury after percutaneous and paddle lead implants did not differ at 0.45% (233 patients) and 0.36% (69 patients)(p=0.12), respectively. Overall, variables associated with a significantly increased OR (95% confidence interval) of developing spinal cord injury included male gender by 1.31 times (1.04 to 1.65)(p=0.02); having a claim for low molecular weight heparin within 30 days by 3.99 times (1.47 to 10.82)(p<0.01); a diagnosis for osteoporosis within 1 year by 1.75 times (1.15 to 2.66)(p<0.01); and a diagnosis of cervical or thoracic spinal canal stenosis within 1 year by 1.99 (1.37 to 2.90)(p<0.001) and 4.00 (2.63 to 6.09)(p<0.0001) times, respectively.

CONCLUSIONS

Overall, our results support the notion that spinal cord stimulator implant continues to be a safe procedure for chronic pain patients. However, risk factor mitigation strategies for the prevention of spinal cord injury after spinal cord stimulator implant should be undertaken prior to performing the procedure.

Spinal cord bioelectronic interfaces: opportunities in neural recording and clinical challenges

Bioelectronic stimulation of the spinal cord has demonstrated significant progress in restoration of motor function in spinal cord injury (SCI). The proximal, uninjured spinal cord presents a viable target for the recording and generation of control signals to drive targeted stimulation. Signals have been directly recorded from the spinal cord in behaving animals and correlated with limb kinematics. Advances in flexible materials, electrode impedance and signal analysis will allow SCR to be used in next-generation neuroprosthetics. In this review, we summarize the technological advances enabling progress in SCR and describe systematically the clinical challenges facing spinal cord bioelectronic interfaces and potential solutions, from device manufacture, surgical implantation to chronic effects of foreign body reaction and stress-strain mismatches between electrodes and neural tissue. Finally, we establish our vision of bi-directional closed-loop spinal cord bioelectronic bypass interfaces that enable the communication of disrupted sensory signals and restoration of motor function in SCI.

Successful Reimplantation of Spinal Cord Stimulator One Year after Device Removal Due to Infection

Spinal cord stimulation is an effective treatment modality for patients with numerous pain conditions. Although proven to be highly successful, device implantation does come with some inherent risks. One of the most challenging complications is perioperative infection. For most patients, a simple trial of oral antibiotics and in-office drainage of any superficial infectious material may be sufficient. Deeper infections with wound dehiscence necessitate device removal and intravenous antibiotic therapy. The question remains, if the device was previously providing pain relief for the patient, when is the appropriate time to reimplant the device after the infection has cleared? We describe the case of explantation of an infected device and successful reimplantation after 1 year.

Outcomes Associated With Infection of Chronic Pain Spinal Implantable Electronic Devices: Insights From a Nationwide Inpatient Sample Study

OBJECTIVES

Chronic pain spinal implantable electronic devices (CPSIEDs) include devices that provide spinal cord stimulation and intrathecal drug therapy. In this study, we sought to evaluate the trends of CPSIED infections, related complications, and outcomes following the treatment of infection.

MATERIALS AND METHODS

The Nationwide Inpatient Sample database contains data from 48 states, and the District of Columbia was used to identify patients with a primary diagnosis of CPSIED infection during the years 2005-2014. Patients with intrathecal pumps for the treatment of spasticity were excluded to limit the study population to patients with chronic pain disorders. Treatments were categorized as: 1) without device removal, 2) pulse generator or pump only removal, 3) intrathecal pump system removal, and 4) spinal cord stimulation system removal. Complications associated with CPSIED infections were identified using administrative billing codes.

RESULTS

During the study period 2005-2014, a total of 11,041 patients were admitted to the hospital with CPSIED infections. The majority of the patients were treated without surgical intervention (56%), and a smaller proportion underwent complete system explantation (22.7%). In-hospital mortality or permanent disability due to paralysis after CPSIED infection was around 1.83% and 2.77%, respectively. Infectious complications such as meningitis, abscess formation, and osteomyelitis occurred in 4.93%, 5.08%, and 1.5%, respectively. The median cost of hospitalization was around US $14,118.00, and the median length of stay was approximately six days (interquartile range = 4-13 days).

CONCLUSIONS

The complications of CPSIED infection were higher among patients that did not undergo device removal.