Neuromodulation for Management of Chronic Pelvic Pain: A Comprehensive Review.

INTRODUCTION: Chronic pelvic pain (CPP) is a symptom that derives from a complex group of heterogeneous pathologies of the pelvic organs. The aim of this study was to review the available evidence on efficacy of neuromodulatory modalities including sacral neuromodulation, dorsal root ganglion stimulation, dorsal column neuromodulation, and pudendal nerve stimulation. METHODS: This narrative review focuses on updated information on neuromodulation for management of chronic pelvic pain. In 2022, we searched English-language studies on neuromodulation, pelvic pain, and chronic pain in a comprehensive search. We searched the following databases: PubMed, Medline, SciHub, Cochrane Database of Systematic Reviews, and Google Scholar. We used the following combinations of keywords: neuromodulation, pelvic pain, chronic pain, chronic pelvic pain, pelvic pain treatment. We tried to include as many recent manuscripts as possible (within the last 3 years) but also included papers older than 3 years if they were particularly relevant to our topic. We also attempted to search for, use, and cite primary manuscripts whenever possible. RESULTS: CPP is a challenging entity to treat because of diagnostic inconsistencies and limited evidence for therapeutic modalities. Our review found evidence suggestive of benefit for all modalities reviewed but the data was of overall low quality with numerous limitations. The literature highlights a lack of randomized controlled trials for neuromodulatory therapies but suggests a growing role for such techniques in treating refractory chronic pelvic pain syndrome (CPPS). CONCLUSIONS: This review explores the available evidence on efficacy of neuromodulatory modalities for CPPS and contextualizes the results with information about the type of neuromodulation, lead location and waveform, pain outcomes and assessment timepoints, and reported adverse effects.

Interventional Therapies for Pain in Cancer Patients: a Narrative Review.

PURPOSE OF REVIEW: Pain is a prevalent symptom in the lives of patients with cancer. In light of the ongoing opioid epidemic and increasing awareness of the potential for opioid abuse and addiction, clinicians are progressively turning to interventional therapies. This article reviews the interventional techniques available to mitigate the debilitating effects that untreated or poorly treated pain have in this population. RECENT FINDINGS: A range of interventional therapies and technical approaches are available for the treatment of cancer-related pain. Many of the techniques described may offer effective analgesia with less systemic toxicity and dependency than first- and second-line oral and parenteral agents. Neuromodulatory techniques including dorsal root ganglion stimulation and peripheral nerve stimulation are increasingly finding roles in the management of oncologic pain. The goal of this pragmatic narrative review is to discuss interventional approaches to cancer-related pain and the potential of such therapies to improve the quality of life of cancer patients.

Management of Lower Extremity Pain from Chronic Venous Insufficiency: A Comprehensive Review.

PURPOSE OF REVIEW: Chronic venous insufficiency is found to some extent in a large proportion of the world's population, especially in the elderly and obese. Despite its prevalence, little research has been pursued into this pathology when compared to similarly common conditions. Pain is often the presenting symptom of chronic venous insufficiency and has significant deleterious effects on quality of life. This manuscript will describe the development of pain in chronic venous insufficiency, and will also review both traditional methods of pain management and novel advances in both medical and surgical therapy for this disease. RECENT FINDINGS: Pain in chronic venous insufficiency is a common complication which remains poorly correlated in recent studies with the clinically observable extent of disease. Although lifestyle modification remains the foundation of treatment for pain associated with chronic venous sufficiency, compression devices and various pharmacologic agents have emerged as safe and effective treatments for pain in these patients. In patients for whom these measures are insufficient, recently developed minimally invasive vascular surgical techniques have been shown to reduce postsurgical complications and recovery time, although additional research is necessary to characterize long-term outcomes of these procedures. This review discusses the latest findings concerning the pathophysiology of pain in chronic venous insufficiency, conservative and medical management, and surgical strategies for pain relief, including minimally invasive treatment strategies.

Obesity Trends Amongst Hospitalized Patients with Spinal Cord Stimulator Implants.

INTRODUCTION: Chronic pain remains an important public health problem as it continues to increase healthcare-related cost. Comorbidities like obesity have been associated with efficacy of spinal cord stimulator (SCS) therapy and worse outcomes. The goal of this study is to investigate the trends of obesity amongst hospitalized patients with SCS therapy as well as healthcare utilization outcomes. METHODS: Using the International Classification of Diseases (ICD) ninth and tenth procedure and diagnosis code, we investigated the National Inpatient Sample (NIS) for patients with SCS implants between 2011 and 2015. Patients received a diagnosis of obesity based on the following categories: class I, II and III obesity. Age, gender, and comorbid conditions of patients with obesity were matched 1:1 on propensity score to those without obesity diagnosis. Our primary outcome was defined as trend of obesity diagnosis. Our secondary outcome, healthcare utilization, included in-hospital cost, length of stay, and discharge location. RESULTS: Between 2011 and 2015, a total of 3893 patients with SCS implants were identified (average age 56 ± 15 years, 58% female, 0.70 ± 1.1 Charlson Comorbidity Index, CCI). Of this cohort, 640 patients were identified as obese. The proportion of patients with obesity diagnosis increased significantly from 13.75% in 2011 to 19.36% in 2015 (p < 0.001). After 1:1 matching on propensity score, 597 patients with obesity were successfully matched to 597 patients without obesity. The total hospital cost for SCS patients with obesity (median $104,845, IQR $74,648-144,292) was not significantly different from patients without obesity diagnosis (median $111,092, IQR $68,990-145,459) (p = 0.161). CONCLUSIONS: The data from our study suggests that there is an increasing rate of obesity diagnosis amongst patients with SCS therapy. However, there was no difference in healthcare utilization between patients with and without obesity. Additional studies may provide more insight into our findings.

Cannabis Use in Hospitalized Patients with Chronic Pain.

INTRODUCTION: To date, no study has reported the prevalence of cannabis use in chronic pain patients. The aim of this study is to investigate the trends in cannabis use among chronic pain in-patients from 2011 to 2015 in the USA. METHODS: Patients were identified from the National Inpatient Sample (NIS) database using the International Classification of Diseases, Ninth and Tenth Revision, diagnosis codes for chronic pain and cannabis use. Annual estimates and trends were determined for cannabis use, patient characteristics, cannabis use among subgroups of chronic pain conditions, cost, length of stay, and associated discharge diagnosis. RESULTS: Between 2011 to 2015, a total of 247,949 chronic pain patients were cannabis users, increasing from 33,189 to 72,115 (P < 0.001). There were upward trends of cannabis use in females (38.7-40.7%; P = 0.03), Medicare insured patients (32.7-40.4%; P < 0.01), patients with lowest annual household income (36.1-40.9%; P = 0.02), patients aged 45-64 years (45.9-49.2%; P < 0.001), and patients with tobacco use disorder (63.8-72.4%; P < 0.0001). Concurrently, cannabis use decreased among patients with opioid use disorder (23.8-19.9%; P < 0.001). Cannabis use increased from 2011 to 2015 in patients with chronic regional pain syndrome, trauma, spondylosis, and failed back surgery syndrome. Adjusted total hospitalization cost increased from $31,271 ($1333) in 2011 to $38,684 ($946) in 2015 (P < 0.001). CONCLUSIONS: Cannabis use increased substantially from 2011 to 2015, while the rates of cannabis use in opioid users down-trended simultaneously. Disparities in cannabis use among subgroups should be explored further.

Prognostic value of hypersensitivity reactions on epidural steroid injection outcomes: a phenotypic signature? A prospective cohort study.

BACKGROUND: Studies have found that diffuse pain, indicative of central sensitization, portends poor interventional outcomes. Multiple chemical sensitivities are associated with signs of central sensitization. We sought to prospectively determine whether hypersensitivity reactions (HR) were associated with epidural steroid injection (ESI) outcomes. METHODS: HR were classified as immune-related or non-immune-related and categorized by number (0=low, 1 or 2=intermediate, ≥3=high). The primary outcome measure was mean reduction in average leg pain score 1 month post-procedure. A positive outcome was defined as a two-point or greater decrease in average leg pain accompanied by satisfaction 1 month post-procedure. RESULTS: The mean number of immune-mediated and non-immune-mediated HR were 0.6±1.2 and 0.8±1.4, respectively. Individuals in the high (n=24) total HR group had a mean reduction in average leg pain of 0.1±2.7, compared with those in the low (n=61; 1.8±2.1, p=0.025) and intermediate groups (n=52; 1.6±3.1, p=0.060). For back pain and categorical successful outcome, those with fewer HR experienced greater benefit. There were no differences in outcomes when patients were stratified by immune-related HR. Among participants in the low, intermediate and high non-immune-mediated HR groups, the mean reductions in average leg pain scores were 1.7±2.5, 1.6±3.0, and -0.2±2.3, respectively (p = 0.002). 51%, 35%, and 12% of people with low, intermediate and high numbers of non-immune-mediated HR experienced a positive categorical outcome, respectively (p=0.007). CONCLUSIONS: Non-immune-related HR were inversely correlated with some ESI outcome measures.

Trends of Co-Morbid Depression in Hospitalized Patients with Failed Back Surgery Syndrome: An Analysis of the Nationwide Inpatient Sample.

INTRODUCTION: Co-morbid depression has been associated with poor outcomes following spine surgery and worsening of low back pain symptoms leading to failed back surgery syndrome (FBSS). Given the increasing focus of healthcare utilization and value-based care, it is essential to understand the demographic and economic data surrounding co-morbid depression amongst patients with FBSS. METHODS: Our study investigated the NIS database for FBSS patients who had co-morbid depression (ICD-9 CM codes 300.4, 301.12, 309.0, 309.1, 311; ICD-10 M96.1) between 2011 and 2015 across 44 states. We obtained demographic and economic data such as age, sex, ethnicity, location, number of in-patient procedures, hospital length of stay, cost of hospital stay, and frequency of routine discharge dispositions. The NIS database represents approximately a 20% sample of discharges from hospitals in the United States. These data are weighted to provide national estimates for the total United States population. National administrative databases (NADs) like National Inpatient Sample (NIS) are a common source of data for spine procedures. This database is appealing to investigators because of ease of data access and large patient sample. The NIS database is a de-identified database that consists of a collection of billing and diagnostic codes used by participating hospitals with the goal of quality control, population monitoring, and tracking procedures. The NIS does not require institutional review board (IRB) approval or exempt determination. RESULTS: Between 2011 and 2015, a total number of 115,976 patients with FBSS were identified. Of these patients, about 23,425 had co-morbid depression. The rate of co-morbid depression in 2015 was 23% with the lowest reported rate being 20% in 2011. Females and Caucasians had consistently higher rates of co-morbid depression compared to males and other ethnic groups respectively. The average length of stay for patients with co-morbid depression fluctuated between 2011 and 2015, with the highest reported at 4.81 days in 2015. The number of procedures increased steadily from 2011 to 2015 with a dip in 2013. The highest number of procedures was reported as 3.94 in 2015. The mean total hospital charges remained stable over time with the largest change being the decrease from 2011 (mean $93,939; 95% CI $80,064-$107,815) to 2012 (mean 82,603; 95% CI $75,127-$90,079). Additionally, patients with FBSS and co-morbid depression were more often discharged home than home with healthcare or to another healthcare facility. CONCLUSIONS: The occurrence of co-morbid depression in hospitalized patients with FBSS increased from 20% in 2011 to 23% in 2015. While direct hospital costs and length of stay remained relatively stable, the number of inpatient procedures performed trended upwards. The exact etiology for this increase in depression prevalence is unknown; additional studies are needed to shed further insight.