A deep insight into pelvic pain and endometriosis: a review of the literature from pathophysiology to clinical expressions

Effects of osteopathic manipulative therapy on recurrent pelvic pain and dyspareunia in women after surgery for endometriosis: a retrospective study

BACKGROUND

Surgical removal of deep infiltrating endometriosis is frequently associated with improvement in symptoms. However, because of the complex pathogenesis of pain in endometriosis that includes central sensitization and myofascial dysfunction, symptoms can persist after surgery. The aim of the present observational study is to explore the effectiveness of osteopathic manipulative treatment (OMT) in reducing persistent pelvic pain and dyspareunia in a sample of symptomatic women surgically treated for endometriosis.

METHODS

Retrospective cohort analysis of 69 patients treated with OMT, for persistent myofascial pain, chronic pelvic pain (CPP) and dyspareunia after surgical eradication of endometriosis. Surgical, clinical and osteopathic reports were retrospectively analyzed in a chart review. Osteopathic interventions included myofascial release, balanced ligamentous/membranous tension and indirect fluidic technique.

RESULTS

During the study period 345 patients underwent surgery for symptomatic endometriosis. Among them, 97 patients (28.1%) complained of post-operative persistent CPP and dyspareunia and 69 patients underwent osteopathic treatment. OMT reports showed a significant improvement of the symptoms after the first OMT session. Particularly, lower scores of CPP (mean NRS 4±4.2 vs. 0.2±0.7, P value.

CONCLUSIONS

OMT, breaking the cycle of pain and normalizing the musculoskeletal pelvic activity, could be a successful technique to treat persistent chronic pain in women surgically treated for endometriosis.

Low Diet Quality and Nutritional Knowledge in Women with Endometriosis: A Pilot Study

Endometriosis is a chronic gynecological disease characterized by ectopic endometrial tissue outside the uterus that can cause chronic pain, dysmenorrhea, fatigue, and infertility. The aim of this study was to assess diet quality and nutritional knowledge of women with endometriosis. A questionnaire was used to collect data on lifestyle, dietary habits and nutritional knowledge from 90 women. More than 80% of women with endometriosis (82.2%) confirmed that diet and lifestyle are related to the progression of endometriosis. After being diagnosed with endometriosis, 77.3% of respondents reported a change in their dietary habits and made various changes to their diet by increasing or eliminating the consumption of certain foods. The majority declared reducing pro-inflammatory products, increasing anti-inflammatory foods, including the consumption of vegetables and fruits, avoiding white/or red/or processed meat, and avoiding sweets. Nevertheless, diet quality as assessed by the pro-healthy diet index (pHDI-10) and the Mediterranean Diet Score (MDS) showed a low intensity of consumption of pro-healthy food (average pHDI-10 value 31.4%; MDS 7.55/14 points, p = 0.0001). Women with endometriosis reported lower than recommended consumption of fruits, vegetables, dairy products and whole grains. A higher percentage of healthy controls had a "good" level of nutritional knowledge than women with endometriosis. The results of our study highlight the need to improve diet quality and nutritional knowledge among women with endometriosis as well as developing targeted dietary recommendations to help improve well-being and reduce the pain symptoms of endometriosis.

Diagnosis of Endometriosis Based on Comorbidities: A Machine Learning Approach

Endometriosis is defined as the presence of estrogen-dependent endometrial-like tissue outside the uterine cavity. Despite extensive research, endometriosis is still an enigmatic disease and is challenging to diagnose and treat. A common clinical finding is the association of endometriosis with multiple diseases. We use a total of 627,566 clinically collected data from cases of endometriosis (0.82%) and controls (99.18%) to construct and evaluate predictive models. We develop a machine learning platform to construct diagnostic tools for endometriosis. The platform consists of logistic regression, decision tree, random forest, AdaBoost, and XGBoost for prediction, and uses Shapley Additive Explanation (SHAP) values to quantify the importance of features. In the model selection phase, the constructed XGBoost model performs better than other algorithms while achieving an area under the curve (AUC) of 0.725 on the test set during the evaluation phase, resulting in a specificity of 62.9% and a sensitivity of 68.6%. The model leads to a quite low positive predictive value of 1.5%, but a quite satisfactory negative predictive value of 99.58%. Moreover, the feature importance analysis points to age, infertility, uterine fibroids, anxiety, and allergic rhinitis as the top five most important features for predicting endometriosis. Although these results show the feasibility of using machine learning to improve the diagnosis of endometriosis, more research is required to improve the performance of predictive models for the diagnosis of endometriosis. This state of affairs is in part attributed to the complex nature of the condition and, at the same time, the administrative nature of our features. Should more informative features be used, we could possibly achieve a higher AUC for predicting endometriosis. As a result, we merely perceive the constructed predictive model as a tool to provide auxiliary information in clinical practice.

A Novel Classification of Endometriosis Based on Clusters of Comorbidities

Endometriosis is a heterogeneous, complex, and still challenging disease, due to its epidemiological, etiological and pathogenic, diagnostic, therapeutic, and prognosis characteristics. The classification of endometriosis is contentious, and existing therapies show significant variability in their effectiveness. This study aims to capture and describe clusters of women with endometriosis based on their comorbidity. With data extracted from electronic records of primary care, this study performs a hierarchical clustering with the Ward method of women with endometriosis with a subsequent analysis of the distribution of comorbidities. Data were available for 4055 women with endometriosis, and six clusters of women were identified: cluster 1 (less comorbidity), cluster 2 (anxiety and musculoskeletal disorders), cluster 3 (type 1 allergy or immediate hypersensitivity); cluster 4 (multiple morbidities); cluster 5 (anemia and infertility); and cluster 6 (headache and migraine). Clustering aggregates similar units into similar clusters, partitioning dissimilar objects into other clusters at a progressively finer granularity-in this case, groups of women with similarities in their comorbidities. Clusters may provide a deeper insight into the multidimensionality of endometriosis and may represent diverse "endometriosis trajectories" which may be associated with specific molecular and biochemical mechanisms. Comorbidity-based clusters may be important to the scientific study of endometriosis, contributing to the clarification of its clinical complexity and variability. An awareness of those comorbidities may help elucidate the etiopathogenesis and facilitate the accurate earlier diagnosis and initiation of treatments targeted toward particular subgroups.

Prolactin and pain of endometriosis

Women experience chronic pain more often than men with some pain conditions being specific to women while others are more prevalent in women. Prolactin, a neuropeptide hormone with higher serum levels in women, has recently been demonstrated in preclinical studies to sensitize nociceptive sensory neurons in a sexually dimorphic manner. Dysregulation of prolactin and prolactin receptors may be responsible for increased pain especially in female predominant conditions such as migraine, fibromyalgia, and pelvic pain. In this review, we focus on the role of prolactin in endometriosis, a condition characterized by pelvic pain and infertility that affects a large proportion of women during their reproductive age. We discuss the symptoms and pathology of endometriosis and discuss how different sources of prolactin secretion may contribute to this disease. We highlight our current understanding of prolactin-mediated mechanisms of nociceptor sensitization in females and how this mechanism may apply to endometriosis. Lastly, we report the results of a systematic review of clinical studies conducted by searching the PubMed and EMBASE databases to identify association between endometriosis and blood levels of prolactin. The results of this search strongly indicate that serum prolactin levels are increased in patients with endometriosis and support the possibility that high levels of prolactin may promote pelvic pain in these patients and increase vulnerability to other comorbid pain conditions likely by dysregulating prolactin receptor expression. Targeting of prolactin and prolactin receptors may improve management of pain associated with endometriosis.

Efficacy of N-Acetylcysteine on Endometriosis-Related Pain, Size Reduction of Ovarian Endometriomas, and Fertility Outcomes

BACKGROUND

Endometriosis is a chronic, estrogen-dependent, inflammatory disease, whose pivotal symptoms are dysmenorrhea, dyspareunia, and chronic pelvic pain (CPP). Besides the usual medical treatments, recent evidence suggests there are potential benefits of oral N-acetylcysteine (NAC) on endometriotic lesions and pain. The primary objective of this prospective single-cohort study was to confirm the effectiveness of NAC in reducing endometriosis-related pain and the size of ovarian endometriomas. The secondary objective was to assess if NAC may play a role in improving fertility and reducing the Ca125 serum levels.

METHODS

Patients aged between 18-45 years old with a clinical/histological diagnosis of endometriosis and no current hormonal treatment or pregnancy were included in the study. All patients received quarterly oral NAC 600 mg, 3 tablets/day for 3 consecutive days of the week for 3 months. At baseline and after 3 months, dysmenorrhea, dyspareunia and CPP were assessed using the Visual Analog Scale score (VAS), while the size of the endometriomas was estimated through a transvaginal ultrasound. Analgesics (NSAIDs) intake, the serum levels of Ca125 and the desire for pregnancy were also investigated. Finally, the pregnancy rate of patients with reproductive desire was evaluated.

RESULTS

One hundred and twenty patients were recruited. The intensity of dysmenorrhea, dyspareunia and CPP significantly improved (p < 0.0001). The use of NSAIDs (p = 0.001), the size of the endometriomas (p < 0.0001) and the serum levels of Ca125 (p < 0.0001) significantly decreased. Among the 52 patients with reproductive desire, 39 successfully achieved pregnancy within 6 months of starting therapy (p = 0.001).

CONCLUSIONS

Oral NAC improves endometriosis-related pain and the size of endometriomas. Furthermore, it decreases Ca125 serum levels and may improve fertility in patients with endometriosis.

Anxiety-related behaviors without observation of generalized pain in a mouse model of endometriosis

Endometriosis is a chronic, hormone-dependent, inflammatory disease, characterized by the presence and growth of endometrial tissue outside the uterine cavity. It is associated with moderate to severe pelvic and abdominal pain symptoms, subfertility and a marked reduction in health-related quality of life. Furthermore, relevant co-morbidities with affective disorders like depression or anxiety have been described. These conditions have a worsening effect on pain perception in patients and might explain the negative impact on quality of life observed in those suffering from endometriosis-associated pain. Whereas several studies using rodent models of endometriosis focused on biological and histopathological similarities with the human situation, the behavioral characterization of these models was never performed. This study investigated the anxiety-related behaviors in a syngeneic model of endometriosis. Using elevated plus maze and the novel environment induced feeding suppression assays we observed the presence of anxiety-related behaviors in endometriosis-induced mice. In contrast, locomotion or generalized pain did not differ between groups. These results indicate that the presence of endometriosis lesions in the abdominal cavity could, similarly to patients, induce profound psychopathological changes/impairments in mice. These readouts might provide additional tools for preclinical identification of mechanisms relevant for development of endometriosis-related symptoms.

Endometriosis and Sexual Functioning: How Much Do Cognitive and Psycho-Emotional Factors Matter?

Women with endometriosis often suffer from genito-pelvic pain. The objective of the present study was to analyze the relationship between cognitive and psycho-emotional factors and sexual functioning of women with endometriosis, comparing women with and without endometriosis. A total of 87 women with endometriosis (EG) and 100 women without endometriosis (CG) completed a socio-demographic questionnaire; the short-form of McGill Pain Questionnaire (SF-MPQ); the Female Sexual Functioning Index (FSFI); the Sexual Distress Scale (SDS); the Symptoms Checklist (SCL-90-R); the Toronto Alexithymia Scale (TAS-20); the Positive and Negative Affects Scale (PANAS); the Sexual Dysfunctional Belief Questionnaire (SDBQ); the Sexual Modes Questionnaire (SMQ); and the Questionnaire of Cognitive Schema Activation in Sexual Context (QCSASC). EG obtained worse scores than CG in SF-MPQ, Pain subscale of FSFI, and SDS. EG reached higher scores than CG on almost all scales of SCL-90-R and lower scores in the “Identifying Feelings” scale of TAS-20. Furthermore, EG reported more negative emotions toward sexuality than CG (PANAS) higher scores on the “Affection Primacy” scale of SDBQ and the “Helpless” sexual cognitive schema of QCSASC than CG. No significant differences were found in SMQ. Sexual health professionals should address psychological, emotional, and cognitive factors since they seem involved in patients’ sexual experiences.

Effects of Breastfeeding on Endometriosis-Related Pain: A Prospective Observational Study

Endometriosis is a gynecological estrogen-dependent disease whose commonest pain symptoms are dysmenorrhea, dyspareunia, and acyclic chronic pelvic pain (CPP). Hormonal changes occurring during breastfeeding seem to reduce pain and disease recurrence. The aim of this observational prospective study was to assess the effect of breastfeeding on pain and endometriotic lesions in patients with endometriosis and to evaluate a possible correlation between the duration of breastfeeding, postpartum amenorrhea, and pain. Out of 156 pregnant women with endometriosis enrolled, 123 who breastfed were included in the study and were monitored for 2 years after delivery; 96/123 exclusively breastfed for at least 1 month. Mode of delivery, type and duration of breastfeeding, intensity of pain symptoms, and lesion size before pregnancy and during the 24-month follow-up were analyzed. All patients experienced a significant reduction in dysmenorrhea proportional to the duration of breastfeeding. CPP was significantly reduced only in women who exclusively breastfed. No significant improvement in dyspareunia was observed. Ovarian endometriomas were significantly reduced. Therefore, breastfeeding, particularly if exclusive, may cause improvement in dysmenorrhea and CPP proportional to the duration of breastfeeding, as well as a reduction in the size of ovarian endometriomas.

Endometrial microbiota is more diverse in people with endometriosis than symptomatic controls

Endometriosis is a chronic, estrogen-dependent gynecological condition affecting approximately 10% of reproductive age women. The most widely accepted theory of its etiology includes retrograde menstruation. Recent reports suggest the uterus is not sterile. Thus, the refluxed menstrual effluent may carry bacteria, and contribute to inflammation, the establishment and growth of endometriotic lesions. Here, we compared and contrasted uterine bacteria (endometrial microbiota) in people with surgically confirmed presence (N = 12) or absence of endometriosis (N = 9) using next-generation 16S rRNA gene sequencing. We obtained an average of > 9000 sequence reads per endometrial biopsy, and found the endometrial microbiota of people with endometriosis was more diverse (greater Shannon Diversity Index and proportion of 'Other' taxa) than symptomatic controls (with pelvic pain, surgically confirmed absence of endometriosis; diagnosed with other benign gynecological conditions). The relative abundance of bacterial taxa enriched in the endometrial microbiota of people with endometriosis belonged to the Actinobacteria phylum (Gram-positive), Oxalobacteraceae (Gram-negative) and Streptococcaceae (Gram-positive) families, and Tepidimonas (Gram-negative) genus, while those enriched in the symptomatic controls belonged to the Burkholderiaceae (Gram-negative) family, and Ralstonia (Gram-negative) genus. Taken together, results suggest the endometrial microbiota is perturbed in people with endometriosis.

Estrogen and progesterone receptors in endometriosis

BACKGROUND

This study aims to identify the presence of estrogen and progesterone hormone receptors in endometriosis implants and to determine whether hormone treatment influences the receptors in these implants.

METHODS

Cross-sectional study with historical data collection. The analysis was conducted on 156 endometriosis implants from 67 patients undergoing endometriosis laparoscopy. The patients were divided into two groups: one group underwent hormone treatment (n = 20) and another group did not receive hormone treatment (n = 47) prior to surgery. Women of reproductive age with clinical pain and/or infertility who were diagnosed with endometriosis and underwent surgery were included. The specimens were analyzed after the estrogen and progesterone hormone receptors underwent immunohistochemistry.

RESULTS

All analyzed topographies presented estrogen and progesterone hormone receptors. Progesterone hormone receptor expression was considerably superior than estrogen receptor expression (p < 0.001).

CONCLUSIONS

Hormone receptors are present in endometriosis implants on the ovarian fossae, uterosacral ligaments, sac fundus, and ovaries. Progesterone receptors predominate in implants, regardless of hormonal treatment.