Effects of Spinal Cord Stimulation in Patients with Chronic Nausea, Vomiting, and Refractory Abdominal Pain

Ten-kHz Spinal Cord Stimulation vs Radiofrequency Ablation of Splanchnic Nerves: A Single-Site Retrospective Comparison of 12-Month Outcomes

OBJECTIVES

A prospective study on 10-kHz spinal cord stimulation (SCS) for various causes of chronic abdominal pain (CAP) showed robust improvements in subjects' pain and function. Radiofrequency ablation of splanchnic nerves (snRFA) has been used in advanced pain management treatment algorithms for CAP. This analysis was designed to provide what we believe is the first comparison of the efficacy of these two therapies. Propensity-score matched analysis (PMA) was performed to compare pain relief and decrease in medication usage in snRFA and SCS for treating refractory CAP.

MATERIALS AND METHODS

Medical records were extracted for consecutive patients with CAP treated from June 2015 to June 2021 who underwent either snRFA or SCS at the Carolinas Pain Institute after positive diagnostic splanchnic block. The patients' diagnoses included gastroparesis, chronic pancreatitis, postsurgical CAP, and other dysmotility syndromes. PMA was performed to produce matched pairs in terms of baseline clinical status, reported pain, and opioid use over 12 months, after treatment was compared in the groups.

RESULTS

PMA produced two well-balanced groups (n = 31) for SCS and snRFA. Analysis showed significant improvement in pain scores in both groups through 12 months, but the mean reduction in reported numerical rating scale points was significantly greater for the SCS group, averaging 4.7 vs 3.0 points for the snRFA group (p < 0.01). Responder rates (≥50% pain relief) similarly diverged at 12 months, with 67.7% vs 30.0% responders in the SCS and snRFA groups, respectively (p = 0.017). Opioid usage did not change in the snRFA group but was reduced in the SCS group at 12 months (p = 0.004).

CONCLUSIONS

SCS provided longer pain relief than did snRFA in this propensity-matched study. Pain scores and opioid usage were significantly less at 12-month follow-up when SCS was used for control of CAP.

Spinal Cord Stimulation for Intractable Visceral Pain Originating from the Pelvic and Abdominal Region: A Narrative Review on a Possible New Indication for Patients with Therapy-Resistant Pain

Aim

Visceral pain, characterized by pain that is diffuse and challenging to localize, occurs frequently and is difficult to treat. In cases where the pain becomes intractable despite optimal medical management, it can affect patients' Quality of Life (QoL). Spinal Cord Stimulation (SCS) has emerged as a potential solution for intractable visceral pain.

Purpose

In this narrative review, we collected all evidence regarding the efficacy of SCS for visceral pain across various underlying conditions.

Methods

A comprehensive literature search was conducted in PubMed, Embase, and Web of Science in which articles published from October 1st, 1963 up to March 7th, 2023 were identified.

Results

Seventy articles were included in this review of which most were retrospective cohort studies, case series and case reports. The studies, often with a small number of participants, reported on SCS for chronic pancreatitis, anorectal pain and bowel disorders, gynaecological diagnoses, visceral pelvic pain, urological disorders and finally general visceral pain. They found positive effects on pain and/or symptom relief, opioid consumption, anxiety and depression and QoL. Complications occurred frequently but were often minor and reversible.

Conclusion

Better screening and selection criteria need to be established to optimally evaluate eligible patients who might benefit from SCS. A positive outcome of a sympathetic nerve block appears to be a potential indicator of SCS effectiveness. Additionally, women receiving SCS for endometriosis had a better outcome compared to other indications. Finally, SCS could also relief functional symptoms such as voiding problems and gastroparesis. Complications could often be resolved with revision surgery. Since SCS is expensive and not always covered by standard health insurance, the incorporation of cost-analyses is recommended. In order to establish a comprehensive treatment plan, including selection criteria for SCS, rigorous prospective, possibly randomized and controlled studies that are diagnosis-oriented, with substantial follow-up and adequate sample sizes, are needed.

Noninvasive electrical neuromodulation for gastrointestinal motility disorders

INTRODUCTION

Gastrointestinal motility disorders are highly prevalent without satisfactory treatment. noninvasive electrical neuromodulation is an emerging therapy for treating various gastrointestinal motility disorders.

AREAS COVERED

In this review, several emerging noninvasive neuromodulation methods are introduced, including transcutaneous auricular vagal nerve stimulation, percutaneous auricular vagal nerve stimulation, transcutaneous cervical vagal nerve stimulation, transcutaneous electrical acustimulation, transabdominal interference stimulation, tibial nerve stimulation, and translumbosacral neuromodulation therapy. Their clinical applications in the most common gastrointestinal motility are discussed, including gastroesophageal reflux disease, functional dyspepsia, gastroparesis, functional constipation, irritable bowel syndrome, and fecal incontinence. PubMed database was searched from 1995 to June 2023 for relevant articles in English.

EXPERT OPINION

Noninvasive neuromodulation is effective and safe in improving both gastrointestinal symptoms and dysmotility; it can be used when pharmacotherapy is ineffective. Future directions include refining the methodology, improving device development and understanding mechanisms of action.

Spinal cord stimulation-induced gastroparesis: A case report

BACKGROUND

Spinal cord stimulation (SCS) involves the utilization of an implantable neurostimulation device, stereotypically used in the treatment of patients with chronic neuropathic pain. While these devices have been shown to have significant clinical benefits, there have also been documented potential complications, including the risk of infection, fractured electrodes, electrode migration, and lack of symptom improvement. In addition, there has been minimal documentation on gastrointestinal (GI) side effects after SCS implantation.

CASE DESCRIPTION

A 42-year-old patient with chronic axial and radicular neuropathic pain in her back and left leg status post multiple lumbar surgeries underwent implantation of an open paddle lead in the T8-T9 region. After the procedure, the patient endorsed a 50% decrease in pain at the 6-week follow-up with no further concerns. However, at the 18 months follow-up, the patient endorsed severe constipation when the SCS was turned on, leading to subsequent evaluation by gastroenterology, motility studies, and a thorough bowel regimen. Symptoms persisted, and the patient ultimately opted for the removal of the SCS implant at 21 months after the initial surgery.

CONCLUSION

While the exact mechanism behind the GI side effects endorsed in this patient is unknown, current literature postulates a variety of theories, including a SCS-induced parasympathetic blockade of the GI tract. Further, investigation is needed to determine the exact effects of SCS on the GI tract.

Neuromodulation for functional upper gastrointestinal diseases

Neuromodulation has recently received a great deal of attention among academic institutions, government funding agents and industries. This mini-review focuses on methods and applications as well as mechanisms of various neuromodulation methods in treating functional diseases of the upper gastrointestinal tract. First, the methods of various neuromodulation are introduced, including direct electrical stimulation at various peripheral nerves, such as the vagus nerve, sacral nerve and spinal cord, direct gastrointestinal electrical stimulation and noninvasive/transcutaneous electrical stimulation. Then, literature search was performed on the clinical applications of these neuromodulation methods for treating gastroesophageal reflux disease, functional dyspepsia and gastroparesis. Due to nature of the mini-review, the search results are selectively presented based on the expert opinions. Finally, a perspective is provided based on the author's own experience in this field of research.

ACG Clinical Guideline: Gastroparesis

Gastroparesis is characterized by symptoms suggesting retention of food in the stomach with objective evidence of delayed gastric emptying in the absence of mechanical obstruction in the gastric outflow. This condition is increasingly encountered in clinical practice. These guidelines summarize perspectives on the risk factors, diagnosis, and management of gastroparesis in adults (including dietary, pharmacological, device, and interventions directed at the pylorus), and they represent the official practice recommendations of the American College of Gastroenterology. The scientific evidence for these guidelines was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation process. When the evidence was not appropriate for Grading of Recommendations, Assessment, Development, and Evaluation, we used expert consensus to develop key concept statements. These guidelines should be considered as preferred but are not the only approaches to these conditions.