Andrea L. Nicol

Pain control following inguinal herniorrhaphy: current perspectives

Inguinal hernia repair is one of the most common surgeries performed worldwide. With the success of modern hernia repair techniques, recurrence rates have significantly declined, with a lower incidence than the development of chronic postherniorrhaphy inguinal pain (CPIP). The avoidance of CPIP is arguably the most important clinical outcome and has the greatest impact on patient satisfaction, health care utilization, societal cost, and quality of life. The etiology of CPIP is multifactorial, with overlapping neuropathic and nociceptive components contributing to this complex syndrome. Treatment is often challenging, and no definitive treatment algorithm exists. Multidisciplinary management of this complex problem improves outcomes, as treatment must be individualized. Current medical, pharmacologic, interventional, and surgical management strategies are reviewed.

Botulinum toxin type a injections for cervical and shoulder girdle myofascial pain using an enriched protocol design.

BACKGROUND:Myofascial pain syndrome is a regional condition of muscle pain and stiffness and is classically characterized by the presence of trigger points in affected musculature. Botulinum toxin type A (BoNT-A) has been shown to have antinociceptive properties and elicit sustained muscle relaxation, thereby possibly affording even greater relief than traditional strategies. Our goal was to determine whether direct injection of BoNT-A into painful muscle groups is effective for cervical and shoulder girdle myofascial pain. METHODS:An enriched protocol design was used, wherein 114 patients with cervical and shoulder girdle myofascial pain underwent injection of BoNT-A to determine their response to the drug. Fifty-four responders were then enrolled in a 12-week, randomized, double-blind, placebo-controlled trial. Pain scales and quality of life measures were assessed at baseline and at routine follow-up visits until completion of the study after 26 weeks. RESULTS:Injection of BoNT-A into painful muscle groups improved average visual numerical pain scores in subjects who received a second dose of BoNT-A compared to placebo (P = 0.019 [0.26, 2.78]). Subjects who received a second dose of BoNT-A had a reduced number of headaches per week (P = 0.04 [0.07, 4.55]). Brief Pain Inventory interference scores for general activity and sleep were improved (P = 0.046 [0.038, 3.700] and 0.02 [0.37, 4.33], respectively) in those who received a second dose of BoNT-A. CONCLUSION:BoNT-A injected directly into painful muscle groups improves average pain scores and certain aspects of quality of life in patients experiencing severe cervical and shoulder girdle myofascial pain.

Potential Mechanisms Underlying Centralized Pain and Emerging Therapeutic Interventions

Centralized pain syndromes are associated with changes within the central nervous system that amplify peripheral input and/or generate the perception of pain in the absence of a noxious stimulus. Examples of idiopathic functional disorders that are often categorized as centralized pain syndromes include fibromyalgia, chronic pelvic pain syndromes, migraine, and temporomandibular disorder. Patients often suffer from widespread pain, associated with more than one specific syndrome, and report fatigue, mood and sleep disturbances, and poor quality of life. The high degree of symptom comorbidity and a lack of definitive underlying etiology make these syndromes notoriously difficult to treat. The main purpose of this review article is to discuss potential mechanisms of centrally-driven pain amplification and how they may contribute to increased comorbidity, poorer pain outcomes, and decreased quality of life in patients diagnosed with centralized pain syndromes, as well as discuss emerging non-pharmacological therapies that improve symptomology associated with these syndromes. Abnormal regulation and output of the hypothalamic-pituitary-adrenal (HPA) axis is commonly associated with centralized pain disorders. The HPA axis is the primary stress response system and its activation results in downstream production of cortisol and a dampening of the immune response. Patients with centralized pain syndromes often present with hyper- or hypocortisolism and evidence of altered downstream signaling from the HPA axis including increased Mast cell (MC) infiltration and activation, which can lead to sensitization of nearby nociceptive afferents. Increased peripheral input via nociceptor activation can lead to “hyperalgesic priming” and/or “wind-up” and eventually to central sensitization through long term potentiation in the central nervous system. Other evidence of central modifications has been observed through brain imaging studies of functional connectivity and magnetic resonance spectroscopy and are shown to contribute to the widespreadness of pain and poor mood in patients with fibromyalgia and chronic urological pain. Non-pharmacological therapeutics, including exercise and cognitive behavioral therapy (CBT), have shown great promise in treating symptoms of centralized pain.

Neurophysiological and Clinical Effects of Laparoscopic Retroperitoneal Triple Neurectomy in Patients with Refractory Postherniorrhaphy Neuropathic Inguinodynia.

Chronic postherniorrhaphy inguinal pain (CPIP) is a complex, major health problem. In the absence of recurrence or meshoma, laparoscopic retroperitoneal triple neurectomy (LRTN) has emerged as an effective surgical treatment of CPIP.

Radiation Exposure in Interventional Pain Management: We Still Have Much to Learn

Fluoroscopic-guided interventional pain management procedures have been increasingly performed in recent years, as they allow for enhanced target accuracy and improved patient safety. Clinical studies and review articles continue to be published that highlight the benefits and usefulness of performing these procedures under fluoroscopic guidance. However, the increased utilization of fluoroscopy has undoubtedly resulted in higher cumulative exposure of ionizing radiation for both the interventional pain management physicians and their patients. The primary source of ionizing radiation exposure during interventional pain procedures comes from scatter radiation that is reflected by the patient. Measures to reduce radiation to the physician include limiting the dose and time of exposure (increasing the distance between the physician and the X-ray tube, collimation, intermittent fluoroscopy, last image hold, pulsed fluoroscopy), and protection from the radiation (lead aprons, glasses, etc.). It is quite difficult to avoid scatter radiation in the interventional pain management procedure setting given the close proximity that the physician must maintain with the patient to perform the procedure. Most interventional procedures carried out for the management of chronic pain require short periods of fluoroscopy time. However, cumulative dose becomes of more concern if physicians routinely perform high volumes of interventional procedures including those procedures with higher fluoroscopy times such as spinal cord stimulator or intrathecal pump implantation and vertebral augmentation. It is well known that cumulative exposure to ionizing radiation is associated with significant adverse conditions including cancer, genetic defects, cataracts, dermatologic issues, and hematologic conditions. Despite these concerning effects, there remains a relative paucity of literature on ionizing radiation exposure and dose among interventional pain management physicians. Furthermore, minimal attention has been paid to the radiation-related effects on our patients, many of whom get numerous interventional pain procedures, ranging from simple to complex, per year, with no personal protective measures in place. The majority of published reports on this topic use fluoroscopic or screening times as a proxy for radiation dose (Table 1). While fluoroscopic times are easily measured, they may not necessarily be correlated to the radiation dose the patient or the physician is receiving and must not be viewed in isolation as a marker of exposure to radiation. Also, fluoroscopic times may vary by mode used (continuous vs. pulsed), the experience of the radiographer, technician, or interventionalist, or difficulties in obtaining a satisfactory image given the severity of degenerative disease or patient body habitus. In general, published data have shown that fluoroscopic times are longer in a university setting where supervision of trainees occurs, as compared to private practice. Even so, there is wide variation in fluoroscopy times and radiation dose in attending physicians in both private practice and university settings. Overweight patients also appear to require significantly longer fluoroscopy times and have higher radiation exposure compared to normal-weight patients. Some studies have reported radiation exposure through dosimetry measurements for a variety of interventional pain management procedures. These studies, which were performed in both private practice and university settings, have shown that radiation dose levels to interventional pain physicians are within regulated acceptable dose limits if appropriate radiation protection measures have been utilized (Table 2). Interpretation of these results has its limitations, as each study utilized different modes of fluoroscopy, varying types of shielding, and measured effective dose over differing lengths of time and at variable locations. Ultimately, DOI: 10.1111/papr.12290

Efficacy of needle-placement technique in radiofrequency ablation for treatment of lumbar facet arthropathy

Background Many studies have assessed the efficacy of radiofrequency ablation to denervate the facet joint as an interventional means of treating axial low-back pain. In these studies, varying procedural techniques were utilized to ablate the nerves that innervate the facet joints. To date, no comparison studies have been performed to suggest superiority of one technique or even compare the prevalence of side effects and complications. Materials and methods A retrospective chart review was performed on patients who underwent a lumbar facet denervation procedure. Each patient’s chart was analyzed for treatment technique (early versus advanced Australian), preprocedural visual numeric scale (VNS) score, postprocedural VNS score, duration of pain relief, and complications. Results Pre- and postprocedural VNS scores and change in VNS score between the two groups showed no significant differences. Patient-reported benefit and duration of relief was greater in the advanced Australian technique group (P=0.012 and 0.022, respectively). The advanced Australian technique group demonstrated a significantly greater median duration of relief (4 months versus 1.5 months, P=0.022). Male sex and no pain-medication use at baseline were associated with decreased postablation VNS scores, while increasing age and higher preablation VNS scores were associated with increased postablation VNS scores. Despite increasing age being associated with increased postablation VNS scores, age and the advanced Australian technique were found to confer greater patient self-reported treatment benefit. Conclusion The advanced Australian technique provides a significant benefit over the early Australian technique for the treatment of lumbar facet pain, both in magnitude and duration of pain relief.

Alternatives to Opioids in the Pharmacologic Management of Chronic Pain Syndromes: A Narrative Review of Randomized, Controlled, and Blinded Clinical Trials

Chronic pain exerts a tremendous burden on individuals and societies. If one views chronic pain as a single disease entity, then it is the most common and costly medical condition. At present, medical professionals who treat patients in chronic pain are recommended to provide comprehensive and multidisciplinary treatments, which may include pharmacotherapy. Many providers use nonopioid medications to treat chronic pain; however, for some patients, opioid analgesics are the exclusive treatment of chronic pain. However, there is currently an epidemic of opioid use in the United States, and recent guidelines from the Centers for Disease Control (CDC) have recommended that the use of opioids for nonmalignant chronic pain be used only in certain circumstances. The goal of this review was to report the current body of evidence-based medicine gained from prospective, randomized-controlled, blinded studies on the use of nonopioid analgesics for the most common noncancer chronic pain conditions. A total of 9566 studies were obtained during literature searches, and 271 of these met inclusion for this review. Overall, while many nonopioid analgesics have been found to be effective in reducing pain for many chronic pain conditions, it is evident that the number of high-quality studies is lacking, and the effect sizes noted in many studies are not considered to be clinically significant despite statistical significance. More research is needed to determine effective and mechanism-based treatments for the chronic pain syndromes discussed in this review. Utilization of rigorous and homogeneous research methodology would likely allow for better consistency and reproducibility, which is of utmost importance in guiding evidence-based care.

Increased Central Nervous System Interleukin-8 in a Majority Postlaminectomy Syndrome Chronic Pain Population

Background and Objectives Multiple processes have been identified as potential contributors to chronic pain, with increasing evidence illustrating an association with aberrant levels of neuroimmune mediators. The primary objectives of the present study were to examine central nervous system cytokines, chemokines, and growth factors present in a chronic pain population and to explore patterns of the same mediator molecules over time. Secondary objectives explored the relationship of central and peripheral neuroimmune mediators while examining the levels of anxiety, depression, sleep quality, and perception of pain associated with the chronic pain patient experience. Methods Cerebrospinal fluid (CSF) from a population of majority postlaminectomy syndrome patients (N = 8) was compared with control CSF samples (N = 30) to assess for significant differences in 10 cytokines, chemokines, and growth factors. The patient population was then followed over time, analyzing CSF, plasma, and psychobehavioral measures. Results The present observational study is the first to demonstrate increased mean CSF levels of interleukin-8 (IL-8; P < 0.001) in a small population of majority postlaminectomy syndrome patients, as compared with a control population. Over time in pain patients, CSF levels of IL-8 increased significantly (P < 0.001). Conclusions These data indicate that IL-8 should be further investigated and psychobehavioral components considered in the overall chronic pain paradigm. Future studies examining the interactions between these factors and IL-8 may identify novel targets for treatment of persistent pain states.

Retrospective Analysis of Intrathecal Drug Delivery: Outcomes, Efficacy, and Risk for Cancer-Related Pain at a High Volume Academic Medical Center

Cancer pain is common and difficult to treat, as conservative medical management fails in approximately 20% of patients for reasons such as intolerable side‐effects or failure to control pain. Intrathecal drug delivery systems (IDDS), while underutilized, can be effective tools to treat intractable cancer pain. This study aims to determine the degree of pain relief, efficacy, and safety of patients who underwent IDDS implantation at a multidisciplinary pain clinic.