Endometriosis-Related Chronic Pelvic Pain

Precision surgery for endometriosis: preventing chronic pelvic pain in patients with higher pre-operative pain scores and in patients of advanced age

OBJECTIVE

Symptom relief can be achieved for many patients with endometriosis by tailored individual treatment. However, therapy resistance is observed in some patients. This study surveyed patient-reported long-term outcomes after laparoscopic endometriosis surgery and evaluated potential pre-operative predictors for insufficient symptom control.

METHODS

This retrospective study included patients with complete surgical endometriosis resection treated between 2013-2016 at the Department of Gynaecology and Reproductive Medicine, Jena University Hospital. Our 2020 survey gathered socio-demographic, reproductive, symptom-related, and subjective general condition data from 122 patients. Overall pain intensity was assessed using a numeric rating scale (NRS) from zero (no pain) to 100 (highest imaginable pain). Clinical records provided additional information.

RESULTS

Median time between surgery and interview was 6 years. Postoperatively, the proportion of patients reporting symptoms was considerably reduced (menstrual pain 32.0% vs. 85.2%, chronic pelvic pain [CPP] 40.2% vs. 67.2%, dyspareunia 34.4% vs. 59.8%, hypermenorrhea 17.2% vs. 49.2%; p < 0.001). The majority of respondents (70%) reported improved subjective general condition. Mean NRS Score significantly decreased from 77.2 to 26.6 (p < 0.001). Among pre-operatively infertile women, 45.2% reported successful pregnancies. However, 20-30% of patients did not respond to therapy in one of the analyzed domains. Multivariate logistic regression identified CPP as a strong predictor for failure in permanent pain reduction (OR 5.544, 95% CI 1.338-22.965, p = 0.018) and risk for reoperation (OR 5.191, 95% CI 1.100-24.501, p = 0.038). Higher pre-operative NRS scores and increasing age were associated with better long-term pain relief.

CONCLUSION

Patients with higher pre-operative pain scores and patients of advanced age benefit significantly from precision surgery, experiencing sustained symptom relief and improved subjective general condition. However, younger patients with CPP and moderate pre-operative pain intensity showed a higher risk for therapy resistance and require multimodal treatment strategies.

Ferroptosis in Endometriosis: Traditional Chinese Medicine Interventions and Mechanistic Insights

Endometriosis (EMS) is a chronic, estrogen-dependent inflammatory disease affecting 5-10% of women of reproductive age, characterized by the growth of endometrial tissue on the outside of the uterus. The dysregulation of iron metabolism leads to the accumulation of iron ions at the lesion sites, resulting in oxidative stress and pro-inflammatory responses that promote the progression of EMS. The mechanisms underlying ferroptosis in EMS primarily involve iron accumulation, lipid peroxidation, and loss of glutathione peroxidase 4 activity. These mechanisms confer resistance to ferroptosis within the ectopic tissues and facilitate cell survival and proliferation. Traditional Chinese medicine (TCM) has demonstrated therapeutic potential for modulating ferroptosis. Studies have shown that TCM monomers may regulate ferroptosis by modulating iron transport proteins and anti-oxidant defense mechanisms. TCM formulas employ distinct treatment strategies depending on the stage of EMS: in the early stages, they promote ferroptosis to control lesion growth, whereas in the later stages, they inhibit ferroptosis to reduce oxidative stress and inflammation in order to improve reproductive health and slow disease progression. This study provides a new perspective on potential therapeutic strategies for the management of EMS by summarizing the role of ferroptosis in its pathological mechanisms and reviewing findings on the use of TCM in regulating ferroptosis.

The connection between endometriosis and secondary dysmenorrhea

Endometriosis (EMS) is a prevalent gynecological condition characterized by the presence of endometrial tissue outside the uterus, often leading to secondary dysmenorrhea (SD), chronic pelvic pain and infertility. This review explores the intricate connection between EMS- associated pain and SD, focusing on the pathophysiological mechanisms underlying dysmenorrhea in EMS. Key contributors to pain include inflammation, aberrant immune responses, neurogenic inflammation, peritoneal irritation, peripheral sensitization, central sensitization and cross-organ sensitization. Understanding the pain pathways in EMS highlights the complexity of symptom manifestation and underscores the necessity for a multidisciplinary approach to management. Clinical manifestations, including chronic pelvic pain, dyspareunia, infertility, gastrointestinal and bladder symptoms, fatigue and malaise, are discussed, emphasizing the diverse impact of EMS on women's health. Various treatment modalities, ranging from pharmacological interventions to surgical and complementary approaches, are outlined to provide comprehensive management strategies for EMS-related menstrual pain/SD. This review aims to enhance understanding and facilitate the effective management of EMS-associated SD, ultimately improving the quality of life for affected individuals.

Role of soluble neural cell adhesion molecule, soluble IL-2 receptor ɑ, and IL-2 in pelvic pain severity and their association with endometriosis in infertile women

INTRODUCTION

Pelvic pain, often associated with endometriosis, significantly affects women's quality of life. This study explored the soluble neural cell adhesion molecules (sNCAM), soluble interleukin 2 receptor α (sIL-2Rα), and IL-2 levels in the serum and peritoneal fluid of infertile women with pelvic pain.

METHODS

We enrolled 86 infertile women aged 24 to 41 years undergoing diagnostic laparoscopy: 44 women with endometriosis and 42 women who acted as controls. Pain intensity was assessed using the visual analog scale. The soluble molecules were measured using enzyme-linked immunosorbent assay.

RESULTS

Serum and peritoneal sNCAM, sIL-2Rα, and IL-2 levels were statistically significantly higher in women with pelvic pain. Both serum and peritoneal sNCAM levels correlated with visual analog scale scores, indicating a relationship between these markers and pain severity. Elevated peritoneal sIL-2Rα levels were also associated with pelvic pain. Receiver operating characteristic curve analysis showed the potential of serum sNCAM in distinguishing between mild and moderate to severe pain.

DISCUSSION

Elevated levels of sNCAM, sIL-2Rα, and IL-2 in serum and peritoneal fluid correlate with pelvic pain severity in infertile women, suggesting their involvement in disease pathogenesis and potential as objective biomarkers for pain assessment in endometriosis. Further research is needed to validate these findings for clinical use.

Investigating the link between severity of dyspareunia and female sexual distress among a group of women with endometriosis: the mediating role of body functionality appreciation

BACKGROUND

While existing studies have predominantly focused on negative body image and its potential link to female sexual distress in women with endometriosis, no studies have investigated how positive body image (ie, body functionality appreciation) mediates the association between dyspareunia severity and sexual distress in this population.

AIM

This study aimed to investigate the mediating role of body functionality appreciation in the relationship between severity of dyspareunia and sexual distress in women living with endometriosis.

METHODS

A total of 232 women with endometriosis (M = 35 years) took part in the study. Participants completed an anonymous questionnaire evaluating dyspareunia severity, functionality appreciation, female sexual distress, sociodemographic factors, and endometriosis-related clinical information. All participants were administered the following questionnaires: numerical rating scale, body functionality appreciation, female sexual distress scale.

OUTCOMES

Using a mediation model, the study analyzed both the direct and indirect effects of dyspareunia severity on sexual distress, with functionality appreciation as a mediator.

RESULTS

The findings suggest that the severity of dyspareunia significantly contributes to sexual distress both directly and indirectly, by diminishing the appreciation for body functionality.

CLINICAL IMPLICATIONS

Clinicians should not only focus on the severity of dyspareunia when evaluating sexual distress in women; instead, they should also acknowledge the protective role of positive body image. Integrated treatments that promote body functionality appreciation could enhance treatment outcomes.

STRENGTHS AND LIMITATIONS

The study is the first to examine the mediating role of body functionality appreciation in the relationship between dyspareunia severity and sexual distress in a sample of women with endometriosis; however, the assessment was cross-sectional and did not encompass other factors that may influence the connection between dyspareunia severity and sexual distress.

CONCLUSION

These findings, in addition to advancing theoretical understanding of the role of positive body image in women with dyspareunia, may be valuable in guiding the design of interventions aimed at reducing sexual distress in women with high levels of dyspareunia severity.

Nociplastic Pain in Endometriosis: A Scoping Review

Endometriosis is an inflammatory chronic condition associated with nociceptive, neuropathic, and nociplastic pain. Central sensitization (CS) is the primary nociplastic pain mechanism. However, there are currently no standardized methods for detecting CS or nociplastic pain. This review aims to identify available tools for characterizing CS/nociplastic pain in endometriosis-related chronic pelvic pain. Following the PRISMA-P protocol, MEDLINE, Embase, Scopus, and PsychINFO databases were searched on 23 April 2024, for the terms "endometriosis", "central sensitization", "nociplastic pain", "widespread pain", and "assessment tools". Publications were selected if they mentioned tool(s) for detecting nociplastic pain or CS in endometriosis patients. Information was extracted on study demographics, assessment types, and the tools used for detection. Of the 379 citations retrieved, 30 papers met the inclusion criteria. When working to identify CS and nociplastic pain, fourteen studies exclusively used patient-reported questionnaires, six used quantitative sensory testing (QST), two used clinical assessments, and eight used multiple approaches combining patient-reported questionnaires and clinical assessment. This review illustrates the diversity of tools currently used to identify CS and nociplastic pain in endometriosis patients. Further research is needed to evaluate their validity and to standardize methods in order to improve the accuracy of nociplastic pain identification and guide treatment.

Management of Endometriosis-Related Pain: Comparing the Effectiveness of Hormonal Therapy, Surgical Interventions, and Complementary Therapies

Endometriosis is a chronic, inflammatory disease characterized by the presence of endometrial-like tissue outside the uterus, affecting women of reproductive age. It is linked with debilitating pain, infertility, and a notable impact on the patient's quality of life. This review aims to highlight the effectiveness of hormonal therapy, surgical procedures, and complementary therapies in managing endometriosis-related pain, providing a comprehensive overview of current treatment options and their implications for clinical practice. The literature reveals that hormonal therapies, including combined oral contraceptives, progestins, and gonadotropin-releasing hormone (GnRH) agonists, are frequently used to manage endometriosis-related pain by suppressing ovarian function and reducing menstrual flow. Surgical interventions, such as laparoscopy and hysterectomy, offer pain relief by removing endometrial lesions but carry risks of recurrence and complications. Complementary therapies, including acupuncture, dietary modifications, and physical therapy, are increasingly recognized for their potential to minimize pain and improve patients' quality of life, though evidence of their effectiveness varies. The review highlights the need for personalized treatment plans that consider patient preferences, symptom severity, and reproductive goals. Future research should concentrate on the long-term outcomes of different therapies, the advancement of non-invasive diagnostic methods, and the identification of biomarkers for tailored treatment approaches. Clinicians are encouraged to adopt an interdisciplinary approach to endometriosis management, integrating medical, surgical, and complementary therapies to optimize patient outcomes.

Unraveling the significance of AGPAT4 for the pathogenesis of endometriosis via a multi-omics approach

Endometriosis is characterized by the ectopic proliferation of endometrial cells, posing considerable diagnostic and therapeutic challenges. Our study investigates AGPAT4's involvement in endometriosis pathogenesis, aiming to unveil new therapeutic targets. Our investigation by analyzing eQTL data from GWAS for preliminary screening. Subsequently, within the GEO dataset, we utilized four machine learning algorithms to precisely identify risk-associated genes. Gene validity was confirmed through five Mendelian Randomization methods. AGPAT4 expression was measured by Single-Cell Analysis, ELISA and immunohistochemistry. We investigated AGPAT4's effect on endometrial stromal cells using RNA interference, assessing cell proliferation, invasion, and migration with CCK8, wound-healing, and transwell assays. Protein expression was analyzed by western blot, and AGPAT4 interactions were explored using AutoDock. Our investigation identified 11 genes associated with endometriosis risk, with AGPAT4 and COMT emerging as pivotal biomarkers through machine learning analysis. AGPAT4 exhibited significant upregulation in both ectopic tissues and serum samples from patients with endometriosis. Reduced expression of AGPAT4 was observed to detrimentally impact the proliferation, invasion, and migration capabilities of endometrial stromal cells, concomitant with diminished expression of key signaling molecules such as Wnt3a, β-Catenin, MMP-9, and SNAI2. Molecular docking analyses further underscored a substantive interaction between AGPAT4 and Wnt3a.Our study highlights AGPAT4's key role in endometriosis, influencing endometrial stromal cell behavior, and identifies AGPAT4 pathways as promising therapeutic targets for this condition.

Magnetic Resonance Imaging of Endometriosis: The Role of Advanced Techniques

Endometriosis is a chronic inflammatory disease that affects about 10% of women, and it is characterized by the presence of endometrial tissue outside the uterine cavity. Associated symptoms are dyspareunia, chronic pelvic pain, and infertility. The diagnosis of endometriosis can be challenging due to various clinical and imaging presentations. Laparoscopy is the gold standard for the diagnosis, but it is an invasive procedure. The literature has increasingly promoted a switch to less invasive imaging techniques, such as ultrasound and magnetic resonance imaging (MRI). The latter, also in relation to the latest technological advances, allows a comprehensive and accurate assessment of the pelvis and it can also identify sites of endometriosis that escape laparoscopic evaluation. Furthermore, MRI has been found to be more accurate than other imaging techniques in relation to its improved sensitivity and specificity in identifying disease sites, also due to the role of new emerging sequences. This article aims to review the current role of advanced MRI applications in the assessment of endometriosis.

Pain from Internal Organs and Headache: The Challenge of Comorbidity

Headache and visceral pain are common clinical painful conditions, which often co-exist in the same patients. Numbers relative to their co-occurrence suggest possible common pathophysiological mechanisms. The aim of the present narrative review is to describe the most frequent headache and visceral pain associations and to discuss the possible underlying mechanisms of the associations and their diagnostic and therapeutic implications based on the most recent evidence from the international literature. The conditions addressed are as follows: visceral pain from the cardiovascular, gastrointestinal, and urogenital areas and primary headache conditions such as migraine and tension-type headache. The most frequent comorbidities involve the following: cardiac ischemic pain and migraine (possible shared mechanism of endothelial dysfunction, oxidative stress, and genetic and hormonal factors), functional gastrointestinal disorders, particularly IBS and both migraine and tension-type headache, primary or secondary dysmenorrhea and migraine, and painful bladder syndrome and headache (possible shared mechanisms of peripheral and central sensitization processes). The data also show that the various visceral pain-headache associations are characterized by more than a simple sum of symptoms from each condition but often involve complex interactions with the frequent enhancement of symptoms from both, which is crucial for diagnostic and treatment purposes.

Neuropelveology for Endometriosis Management: A Systematic Review and Multilevel Meta-Analysis

Background: Despite the availability of treatments such as surgery and hormonal therapy, women with endometriosis often endure chronic problems. This review aims to evaluate the effectiveness and safety of neuropelveology. Methods: In a systematic review with a meta-analysis, we searched three electronic databases: MEDLINE (PubMed), Scopus, Embase, and Web of Science (WOS). The search was conducted in January 2024 with no date or language restrictions using a carefully curated set of keywords. We conducted a comprehensive review, including all observational and clinical trials reporting data on neuropelveology approaches in the management of endometriosis, irrespective of geographical location. The studies included in our review were required to be published in peer-reviewed journals and be available in any language, with at least an abstract in English. The data of all included studies were summarized in excel (version 19) and were analyzed by Comprehensive Meta-analysis v3.3 (Biostat) and STATA (version 17). A multilevel meta-analysis was performed on studies with two arms (intervention and control) to evaluate the efficacy of neuropelveology in managing women with endometriosis. Results: After screening 476 records, 30 studies, published from 1952 to 2021, were included in this review, each employing various methodologies. The studies were divided into the following three categories: (a) efficacy of neurectomy or nerve resection (n = 20), (b) efficacy of neurolysis (nerve blocks) (n = 4), and (c) efficacy of neuromodulation (n = 6) in the management of endometriosis. Among the studies evaluating the efficacy of neurectomy or nerve resection, 10 studies (with 18 group comparisons) were included in the random-effects meta-analysis. Treatment success (not occurrence of pain) was higher with neurectomy vs. controls (RR = 0.497, 95% CI = 0.236 to 1.04, p = 0.06 (for experimental studies) and RR = 0.248, 95% CI = 0.14 to 0.43, p < 0.001 (for observational studies)), representing a 50% and 75.2% risk reduction in the recurrence of pain in experimental and observational studies, respectively. Similarly, neurolysis, particularly superior hypogastric plexus blocks and uterine nerve ethanol neurolysis, demonstrated encouraging outcomes in pain reduction and an improved quality of life for women with endometriosis. The efficacy of neuromodulation in managing endometriosis symptoms appears promising but requires further investigation. Conclusions: In conclusion, neuropelveology approaches, such as neurectomy, neurolysis, and neuromodulation, offer significant potential for pain reduction in endometriosis patients, albeit with risks of complications and high recurrence rates, necessitating careful patient selection and long-term monitoring.

Study on the Mechanisms of Glrα3 in Pain Sensitization of Endometriosis

Endometriosis, often associated with chronic pelvic pain, can lead to anxiety and depression. This study investigates the role and mechanism of Glycine receptor alpha 3 (Glrα3) in the central sensitization of pain in endometriosis, aiming to identify new therapeutic targets. Using a Glrα3 knockout mouse model of endometriosis, we employed behavioral tests, qPCR, immunofluorescence, Nissl staining, MRI, and Western blot to assess the involvement of Glrα3 in central pain sensitization. Our results indicate that endometriosis-induced hyperalgesia and anxiety-depressive-like behaviors are linked to increased Glrα3 expression. Chronic pain in endometriosis leads to gray matter changes in the sensory and insular cortices, with Glrα3 playing a significant role. The inhibition of Glrα3 alleviates pain, reduces neuronal abnormalities, and decreases glial cell activation. The absence of Glrα3 effectively regulates the central sensitization of pain in endometriosis by inhibiting glial cell activation and maintaining neuronal stability. This study offers new therapeutic avenues for the clinical treatment of endometriosis-related pain.

Nerve Bundle Density and Expression of NGF and IL-1β Are Intra-Individually Heterogenous in Subtypes of Endometriosis

Endometriosis is a gynecological disorder associated with local inflammation and neuroproliferation. Increased nerve bundle density has been attributed to increased expression of nerve growth factor (NGF) and interleukin-1β (IL-1β). Immunohistochemical analysis was carried out on 12 patients presenting with all three anatomic subtypes of endometriosis (deep, superficial peritoneal, endometrioma) at surgery, with at least two surgically excised subtypes available for analysis. Immunolocalization for nerve bundle density around endometriosis using protein gene product 9.5 (PGP9.5), as well as NGF and IL-1β histoscores in endometriosis epithelium/stroma, was performed to evaluate differences in scores between lesions and anatomic subtypes per patient. Intra-individual heterogeneity in scores across lesions was assessed using the coefficient of variation (CV). The degree of score variability between subtypes was evaluated using the percentage difference between mean scores from one subtype to another subtype for each marker. PGP9.5 nerve bundle density was heterogenous across multiple subtypes of endometriosis, ranging from 50.0% to 173.2%, where most patients (8/12) showed CV ≥ 100%. The percentage difference in scores showed that PGP9.5 nerve bundle density and NGF and IL-1β expression were heterogenous between anatomic subtypes within the same patient. Based on these observations of intra-individual heterogeneity, we conclude that markers of neuroproliferation in endometriosis should be stratified by anatomic subtype in future studies of clinical correlation.

Association between KRAS and PIK3CA Mutations and Progesterone Resistance in Endometriotic Epithelial Cell Line

Although endometriosis is a benign disease, it is associated with cancer-related gene mutations, such as KRAS or PIK3CA. Endometriosis is associated with elevated levels of inflammatory factors that cause severe pain. In a previous study, we demonstrated that KRAS or PIK3CA mutations are associated with the activation of cell proliferation, migration, and invasion in a patient-derived immortalized endometriotic cell line, HMOsisEC10. In this study, we investigated the effects of these mutations on progesterone resistance. Since the HMOsisEC10 had suppressed progesterone receptor (PR) expression, we transduced PR-B to HMOsisEc10 cell lines including KRAS mutant and PIK3CA mutant cell lines. We conducted a migration assay, invasion assay, and MTT assay using dienogest and medroxyprogestrone acetate. All cell lines showed progesterone sensitivity with or without mutations. Regarding inflammatory factors, real-time quantitative RT-PCR revealed that the KRAS mutation cell line exhibited no suppression of Cox-2 and mPGES-1 on progesterone treatment, whereas IL-6, MCP-1, VEGF, and CYP19A1 were significantly suppressed by progesterone in both mutated cell lines. Our results suggest that KRAS mutation and PIK3CA mutation in endometriotic cells may not be associated with progesterone resistance in terms of aggressiveness. However, KRAS mutations may be associated with progesterone resistance in the context of pain.

Advanced Insights into Human Uterine Innervation: Implications for Endometriosis and Pelvic Pain

(1) Background: Understanding uterine innervation, an essential aspect of female reproductive biology, has often been overlooked. Nevertheless, the complex architecture of uterine innervation plays a significant role in conditions such as endometriosis. Recently, advances in histological techniques have provided unprecedented details about uterine innervation, highlighting its intricate structure, distribution, and density. The intricate nature of uterine innervation and its influence on pathologies such as endometriosis has garnered increasing attention. (2) Objectives: This review aims to compile, analyze, and summarize the existing research on uterine innervation, and investigate its implications for the pathogenesis of endometriosis and associated pain. (3) Methods: A systematic review was conducted in line with PRISMA guidelines. Using the PubMed database, we searched relevant keywords such as "uterine innervation", "endometriosis", and "pain association". (4) Results: The initial literature search yielded a total of 3300 potential studies. Of these, 45 studies met our inclusion criteria and were included in the final review. The analyzed studies consistently demonstrated that the majority of studies focused on macroscopic dissection of uterine innervation for surgical purposes. Fewer studies focused on micro-innervation for uterine innervation. For endometriosis, few studies focused on neural pain pathways whereas many studies underlined an increase in nerve fiber density within ectopic endometrial tissue. This heightened innervation is suggested as a key contributor to the chronic pain experienced by endometriosis patients. (5) Conclusions: The understanding of uterine innervation, and its alterations in endometriosis, offer promising avenues for research and potential treatment.