Endometriosis and mechanisms of pelvic pain

Deep Dyspareunia in Endometriosis: Role of the Bladder and Pelvic Floor

INTRODUCTION

The etiology of endometriosis-associated deep dyspareunia may include direct endometriosis-specific factors (eg, stage or invasiveness of disease) and/or indirect contributors such as bladder/pelvic floor dysfunction (eg, related to myofascial mechanisms or nervous system sensitization).

AIM

This study aimed to determine whether bladder/pelvic floor tenderness and painful bladder syndrome were associated with severity of deep dyspareunia in women with endometriosis, regardless of Stage (I/II vs III/IV) or other endometriosis-specific factors.

METHODS

Observational study from a prospective patient registry (January 2014 to December 2016) at a tertiary centre for endometriosis. Included were women aged 18 to 49 years who had surgical removal and histopathologic confirmation of endometriosis at the centre. Cases with Stage I/II vs Stage III/IV endometriosis were analyzed separately. Bivariate associations with the primary outcome (severity of deep dyspareunia) were tested for bladder/pelvic floor tenderness, painful bladder syndrome, as well as endometriosis-specific factors identified at the time of laparoscopic surgery (eg, deep infiltrating endometriosis) and demographic factors (eg, age). Multivariable ordinal logistic regression was carried out to adjust for factors associated with the primary outcome.

MAIN OUTCOME MEASURE

Primary outcome was severity of deep dyspareunia on an 11-point numeric rating scale, categorized as none/mild (0-3), moderate (4-6), and severe (7-10), from a preoperative self-reported questionnaire.

RESULTS

Overall, 411 women had surgically confirmed endometriosis: 263 had Stage I/II and 148 had Stage III/IV endometriosis. Among women with Stage I/II endometriosis, severity of deep dyspareunia was associated with both bladder/pelvic floor tenderness and painful bladder syndrome (AOR = 1.94, 95% CI: 1.11-3.38, P = .019 and AOR = 1.99, 95% CI: 1.15-3.44, P = .013, respectively), independent of endometriosis-specific factors or other factors associated with deep dyspareunia severity. Similar associations were found in women with Stage III/IV endometriosis (bladder/pelvic floor tenderness AOR =2.51, 95% CI: 1.25-5.02, P = .01, painful bladder syndrome: AOR = 1.90, 95% CI: 1.01-3.57, P = .048).

CLINICAL IMPLICATIONS

Myofascial or nervous system mechanisms may be important for deep dyspareunia in women with endometriosis, even in those with moderate-to-severe disease (Stage III/IV).

STRENGTHS & LIMITATIONS

Strengths include the prospective registry, and histological confirmation of endometriosis and staging by experienced endometriosis surgeons. Limitations include assessment of only one pelvic floor muscle (levator ani).

CONCLUSION

In women with Stage I/II or Stage III/IV endometriosis, severity of deep dyspareunia was strongly associated with bladder/pelvic floor tenderness and painful bladder syndrome, independent of endometriosis-specific factors, which suggests the role of myofascial or sensitization pain mechanisms in some women with deep dyspareunia. Orr NL, Noga H, Williams C, et al. Deep Dyspareunia in Endometriosis: Role of the Bladder and Pelvic Floor. J Sex Med 2018;15:1158-1166.

Rethinking mechanisms, diagnosis and management of endometriosis

Endometriosis is a chronic inflammatory disease defined as the presence of endometrial tissue outside the uterus, which causes pelvic pain and infertility. This disease should be viewed as a public health problem with a major effect on the quality of life of women as well as being a substantial economic burden. In light of the considerable progress with diagnostic imaging (for example, transvaginal ultrasound and MRI), exploratory laparoscopy should no longer be used to diagnose endometriotic lesions. Instead, diagnosis of endometriosis should be based on a structured process involving the combination of patient interviews, clinical examination and imaging. Notably, a diagnosis of endometriosis often leads to immediate surgery. Therefore, rethinking the diagnosis and management of endometriosis is warranted. Instead of assessing endometriosis on the day of the diagnosis, gynaecologists should consider the patient's 'endometriosis life'. Medical treatment is the first-line therapeutic option for patients with pelvic pain and no desire for immediate pregnancy. In women with infertility, careful consideration should be made regarding whether to provide assisted reproductive technologies prior to performing endometriosis surgery. Modern endometriosis management should be individualized with a patient-centred, multi-modal and interdisciplinary integrated approach.

Identification of predictors for acute postoperative pain after gynecological laparoscopy (STROBE-compliant article)

While the pain after gynecological laparoscopy is assumed to be minor, many women suffer from unexpected postoperative pain in the post-anesthesia care unit (PACU). Prior identification of these patients is significant for effective analgesia. Therefore, we sought to determine the predictors for acute postoperative pain after gynecological laparoscopy. The data of 280 patients undergoing gynecological laparoscopy were analyzed. Data included demographic characteristics, previous obstetric/gynecologic surgical history, menstruation pattern including dysmenorrhea severity, gynecological hormone administration history, and surgical data (surgical time, endometriosis severity, adhesion, drainage insertion, and surgery type). Univariate analysis and binary logistic regression were used to evaluate predictors for substantial pain in the PACU after gynecologic laparoscopy. Among the 280 patients, 115 (41%) suffered from substantial postoperative pain in the PACU. Whenever the level of dysmenorrhea became more severe (none → mild → moderate → severe), the risk of substantial pain in the PACU increased 2.9-fold (odds ratio [OR] 2.92, 95% confidence interval [CI] 2.11-4.03, P < .001). Moreover, patients undergoing laparoscopy for ectopic pregnancy had a higher risk of substantial pain compared with the others (OR 3.11, 95% CI 1.36-7.12, P = .007). Other factors did not show a significant association with substantial pain. Patients with preoperative severe dysmenorrhea and those undergoing laparoscopy for ectopic pregnancy should be considered to have a high risk of substantial postoperative pain in the PACU so that they receive prompt and aggressive analgesic intervention. In particular, dysmenorrhea severity is clinically valuable as a useful predictor for substantial pain after gynecological laparoscopy.

Clinical evaluation of the oral gonadotropin-releasing hormone-antagonist elagolix for the management of endometriosis-associated pain

Endometriosis is an estrogen-dependent chronic inflammatory disease associated with pelvic pain symptoms that are often severe, mainly dysmenorrhea, nonmenstrual pelvic pain and dyspareunia. This condition is also associated with peripheral and central sensitization. The current medical treatment options for endometriosis-associated pain are limited. Recently, the US FDA approved the novel, oral, nonpeptide gonadotropin-releasing hormone antagonist elagolix for the management of moderate to severe endometriosis-associated pain. Elagolix produces dose-dependent estrogen suppression, from partial suppression at lower doses to nearly full suppression at higher doses. This review article summarizes the current understanding of the pathophysiology of endometriosis, with a focus on the role of estrogen and the mechanisms of pain symptoms, and reviews the clinical development of elagolix in women with endometriosis-associated pain.

Reduced inflammatory state promotes reinnervation of endometriotic-like lesions in TNFRp55 deficient mice

Endometriosis is a chronic gynecological disease, characterized by growth of endometrial tissue in ectopic sites due to alteration of peritoneal homeostasis and deregulation of apoptosis. Here we have examined whether TNFRp55 deficiency modulates the pro-inflammatory state and the reinnervation of endometriotic-like lesions in mice. Two-month-old female C57BL/6 mice, eight wild type (WT) and eight TNFRp55-/- (KO) were used in the study. Endometriotic-like lesions were induced experimentally. The right uterine horn was removed from the animal, divided longitudinally, cut in three square pieces and sutured to the intestine mesentery. After 4 weeks, the lesions and the peritoneal fluid were collected. The level of TNFα in the peritoneal fluid was evaluated by enzyme-linked immunosorbent assay (EIA). The expressions of COX2, GRα and GRβ were evaluated in the lesions by western blot and immunohistochemistry. β-III TUBULIN, BDNF and NGF protein concentrations were evaluated in the lesions by western blot. Gene expression of Pgp 9.5, SP and Th was analyzed by RT-PCR, whereas relative concentrations of TRKA, NTRp75, phosphorylated NFκB (pNFκB) and total NFκB in lesions were measured by EIA. Compared with the WT group, the KO mice showed lower TNFα levels in the peritoneal fluid and lower numbers of COX2 immunoreactive cells along with increased expression of GRα, β-III TUBULIN, Pgp 9.5, SP, Th, BDNF, NGF, NTRp75 and pNFκB in the lesions. Future histological studies will be necessary to confirm the sensory/sympathetic imbalance in the endometriotic-like lesions of the KO mice. Our results suggest that a reduced inflammatory state promotes reinnervation of endometriotic-like lesions in TNFRp55-/- mice. Chronic deregulation of TNF receptors can have serious consequences for women with advanced endometriosis.

Effects of omega-6/3 and omega-9/6 nutraceuticals on pain and fertility in peritoneal endometriosis in rats

Purpose:

To evaluate the effects of the nutraceuticals omega-6/3 and omega-9/6 on endometriosis-associated infertility and pain.

Methods:

Controlled experimental study, with each group composed of eight female rats. Fertility groups: sham-operated control (0.9% saline solution); control with endometriosis (0.9% saline); omega-6/3 (1.2 g/kg/day); omega-9/6 (1.2 g/kg/day); and meloxicam (0.8 mg/kg/day). Pain groups: sham-operated control (0.9% saline); control with endometriosis (0.9% saline); omega-6/3 (1.2 g/kg/day); omega-9/6 (1.2 g/kg/day); medroxyprogesterone acetate (5 mg/kg/every 3 days); and meloxicam (0.8 mg/kg/day). Peritoneal endometriosis was surgically induced. Pain was evaluated with the writhing test. Fertility was evaluated by counting the number of embryos in the left hemi-uterus.

Results:

The mean number of writhings was as follows: sham-operated, 11.1 ± 2.9; control with endometriosis, 49.3 ± 4.4; omega-6/3, 31.5 ± 2.7; omega-9/6, 34.1 ± 4.5; medroxyprogesterone acetate, 2.1 ± 0.8; meloxicam, 1 ± 0.3. There was a significant difference between both controls and all drugs used for treatment. Regarding fertility, the mean values were as follows: sham-operated, 6.8 ± 0.6; control with endometriosis, 4.2 ± 0.7; omega-6/3, 4.7 ± 1; omega-9/6, 3.8 ± 0.9; and meloxicam, 1.8 ± 0.9.

Conclusions:

The omega-6/3 and omega-9/6 nutraceuticals decreased pain compared to the controls. There was no improvement in fertility in any of the tested groups.

Endometriotic lesions

Endometriosis is a complex gynaecological condition affecting women of reproductive age. It is characterised by the presence of lesions containing endometrial glands and stroma outside the uterus. The disease is typically associated with pelvic pain (including dysmenorrhoea and dyspareunia), infertility and bowel-related symptoms. Endometriotic lesions have a highly variable presentation and most commonly occur in the abdominal cavity. These lesions are broadly classified into peritoneal, ovarian and deep infiltrating endometriosis. There have been observations of increased density of nerve fibres and neurological molecules in the endometriotic lesions compared to the uninvolved peritoneum of women without endometriosis and the presence of unmyelinated nerve fibres were higher near the glands. The lesion sites are characterised by a range of immunological alterations, and specific immune cell populations have also been known to synthesise and secrete neurogenic factors. Endometriotic lesions are capable of producing prostaglandins which are direct generators of pain and are capable of inducing inflammation. Diagnosing the disease involves direct visualisation of the lesions through a laparoscopic or laparotomy, which is followed by histopathological examination of biopsied or excised lesions. The staging of endometriosis due to its complexity is highly variable as presentation and gaps in knowledge pose a great challenge in the classification of the disease. The medical management of endometriosis aims at providing adequate analgesia and suppression of the activity of the lesion. A better understanding of endometriotic lesion relationships between innervations and specific clinical characteristics may elucidate aspects of pain mechanisms and infertility in endometriosis and facilitate the development of novel therapeutic approaches.

Pelvic floor dysfunction at transperineal ultrasound and voiding alteration in women with posterior deep endometriosis

INTRODUCTION AND HYPOTHESIS

Posterior deep infiltrating endometriosis (DIE) has been associated with pelvic floor muscle (PFM) alteration and voiding dysfunction (VD). The aim of this study is to evaluate the correlation between the presence of VD and altered PFM morphometry, objectively evaluated using 3D/4D transperineal ultrasound at rest and during dynamic maneuvers, in patients with posterior DIE.

METHODS

A prospective study was conducted on 108 symptomatic women scheduled for surgical removal of posterior DIE. The study population was divided in two groups according to presence or absence of VD on the Bristol Female Lower Urinary Tract Symptoms (BFLUTS). A 3D/4D transperineal ultrasound was performed to compare the following PFM morphometric parameters: levator hiatus area (LHA), antero-posterior (AP) and left-right (LR) diameters and levator ani muscle (LAM) coactivation. LAM coactivation was defined as the paradoxical contraction of the pelvic floor muscle during the Valsalva maneuver causing a smaller LHA than in the resting state.

RESULTS

Forty-eight (45.2%) women presented VD, while 60 (54.8%) women did not report any voiding complaints. Baseline characteristics did not significantly differ between the two groups. We did not find any significant statistical differences in PFM parameters between the two groups, except for a higher rate of levator ani muscle coactivation in women with VD compared with women without VD [64.6% (31/48) versus 31.7% (19/60), respectively; p = < 0.001].

CONCLUSIONS

In women affected by posterior DIE, LAM coactivation at 3D/4D transperineal ultrasound seems to be more frequent in patients with than without VD.

"I feel like I'm being stabbed by a thousand tiny men": The challenges of communicating endometriosis pain

Endometriosis, as a widespread gynecological condition, affects an estimated 1 in 10 women and yet has a worldwide average diagnosis length of 7.5 years. Causing incapacitating pain, among other associated manifestations, the condition severely impacts on women's lives. This article uses online survey data to investigate how pre-diagnosis endometriosis pain is conceptualized and articulated in order to explore communication challenges reported in early consultations that can potentially be seen to play a role in diagnosis delay. The findings of this study indicate that women feel that they do not have the appropriate tools to describe their pain and, in many instances, feel dismissed therefore prolonging diagnosis. The article finds that the majority of the pain descriptors identified use elaborate metaphorical scenarios to convey the intensity of the pain and concludes with some reflections on the issue of metaphorical language in endometriosis pain communication practices while calling for interdisciplinary work in order to devise appropriate tools for endometriosis pain communication.

Increased mast cells in endocervical smears of women with dysmenorrhea

Background:

Mast cells are observed in peritoneal endometriosis which causes dysmenorrhea. However, there is no report about the relationship between endocervical mast cells and dysmenorrhea. The aim of this study is to evaluate the relationship using endocervical smears.

Materials and Methods:

Between January 2016 and June 2016, patients filled out a questionnaire regarding dysmenorrhea and were classified into the dysmenorrhea or the control group (without dysmenorrhea). Patients underwent endocervical brushing and endocervical smears were obtained. The smears were stained with methylene blue to detect mast cells. The number of mast cells per slide was counted by microscopy and recorded.

Results:

Eighty-nine patients were enrolled in this study (dysmenorrhea group, 34; control group, 55). The median number of mast cells present in the endocervical one slides was 35 (interquartile range, 17–58) and 2 (interquartile range, 0–6) in the dysmenorrhea and control groups, respectively. There was a significant difference in the number of mast cells between the two groups (P < 0.0001).

Conclusion:

More mast cells were observed in the endocervical smears of women with dysmenorrhea than in those of women without dysmenorrhea.

The Role of Tumor Necrosis Factor α in the Biology of Uterine Fibroids and the Related Symptoms

Uterine fibroids (UFs) are the most common benign tumors of the female genital tract. The incidence of UFs has been estimated at 25⁻80% depending on selected population. The pathophysiology of UFs remains poorly understood. The transformation of smooth muscle cells of the uterus into abnormal, immortal cells, capable of clonal division, is the main component of all pathways leading to UF tumor formation and tumor necrosis factor α (TNF-α) is believed to be one of the key factors in this field. TNF-α is a cell signaling protein involved in systemic inflammation and is one of the cytokines responsible for the acute phase reaction. This publication presents current data about the role of tumor necrosis factor α in the biology of UFs and the related symptoms. TNF-α is an extremely important cytokine associated with the biology of UFs, UF-related symptoms and complaints. Its concentration has been proven to be elevated in women with clinically symptomatic UFs. The presented data suggest the presence of an "inflammation-like" state in women with UFs where TNF-α is a potent inflammation inducer. The origin of numerous symptoms reported by women with UFs can be traced back to the TNF-α influence. Nevertheless, our knowledge on this subject remains limited and TNF-α dependent pathways in UF pathophysiology should be investigated further.

Absence of formyl peptide receptor 1 causes endometriotic lesion regression in a mouse model of surgically-induced endometriosis

Endometriosis is a female disease in which endometrial tissues grows outside the uterus. Patients showed alterations in endocrine and immune systems. Endometriotic lesions are characterized by deregulated interaction between immune cells and tissue cells. The formyl peptide receptor 1 (Fpr1) is expressed by both immune and stromal cells including epithelial cells. We investigated the development of the physiopathology of the surgically-induced endometriosis in Fpr1 KO mice compared to WT animals. Operated Fpr1 KO mice showed lower duration of uterine pain behaviors, lower size of developed cysts and reduced mast cell numbers. Immunohistochemical analyses indicated changes in NGF, VEGF and ICAM-1 expression associated with the pathology, which were reduced in absence of the Fpr1 gene. Molecular analyses indicated that in absence of Fpr1 there was reduced neutrophils accumulation and nitrosative stress formation, NF-κB translocation into the nucleus as well as NRLP3 inflammasome signalling. Fpr1 gene deletion caused reduction of resistance to the apoptosis, assessed by TUNEL assay. We underline the pathogenic role of Fpr1 in experimental endometriosis, which is the result of modulation of immune cell recruitment, suggesting it as a new target to control the pathologic features of endometriotic lesions.

Short-term histopathological effects of dienogest therapy on ovarian endometriomas: in vivo, nonrandomized, controlled trial

Ovarian endometriosis is a common gynecological disorder. To date, progestins are recommended as the first-line medical treatment for symptomatic ovarian endometriosis. The aim of this study was to evaluate the main histopathological effects of short-term dienogest therapy in patients with ovarian endometriomas scheduled for surgery. A prospective, nonrandomized controlled trial, including 70 symptomatic women with single ovarian endometriotic cyst (diameter between 30-50 mm) was conducted. Women scheduled for surgery were divided into two groups, depending on the treatment established at enrollment: 36 women received progestin therapy with dienogest (P group) and 34 women received no therapy (C group). At histopathological examination necrosis, inflammation, decidualization, glandular atrophy and angiogenesis were blindly evaluated. At tissue level, decidualization was significantly more frequent in P group compared to C group (p = .001). A nonsignificant tendency (p = .29) towards a slight decreased inflammation in P group was found. No significant differences were observed between the two groups in terms of necrosis, glandular atrophy and angiogenesis. The study suggests that high decidualization rate and the tendency to reduced inflammatory reaction in the short-term administration of dienogest might contribute to its therapeutic efficacy.

[Definition, description, clinicopathological features, pathogenesis and natural history of endometriosis: CNGOF-HAS Endometriosis Guidelines]

Endometriosis and adenomyosis are histologically defined. The frequency of endometriosis cannot be precisely estimated in the general population. Endometriosis is considered a disease when it causes pain and/or infertility. Endometriosis is a heterogeneous disease with three well-recognized subtypes that are often associated with each other: superficial endometriosis (SUP), ovarian endometrioma (OMA), and deep infiltrating endometriosis (DIE). DIE is frequently multifocal and mainly affects the following structures: the uterosacral ligaments, the posterior vaginal cul-de-sac, the bladder, the ureters, and the digestive tract (rectum, recto-sigmoid junction, appendix). The role of menstrual reflux in the pathophysiology of endometriosis is major and explains the asymmetric distribution of lesions, which predominate in the posterior compartment of the pelvis and on the left (NP3). All factors favoring menstrual reflux increase the risk of endometriosis (early menarche, short cycles, AUB, etc.). Inflammation and biosteroid hormones synthesis are the main mechanisms favoring the implantation and the growth of the lesions. Pain associated with endometriosis can be explained by nociception, hyperalgia, and central sensitization, associated to varying degrees in a single patient. Typology of pain (dysmenorrhea, deep dyspareunia, digestive or urinary symptoms) is correlated with the location of the lesions. Infertility associated with endometriosis can be explained by several non-exclusive mechanisms: a pelvic factor (inflammation), disrupting natural fertilization; an ovarian factor, related to oocyte quality and/or quantity; a uterine factor disrupting implantation. The pelvic factor can be fixed by surgical excision of the lesions that improves the chance of natural conception (NP2). The uterine factor can be corrected by an ovulation-blocking treatment that improves the chances of getting pregnant by in vitro fertilization (NP2). The impact of endometrioma exeresis on the ovarian reserve (NP2) should be considered when a surgery is scheduled. Endometriosis is a multifactorial disease, resulting from combined action of genetic and environmental factors. The risk of developing endometriosis for a first-degree relative is five times higher than in the general population (NP2). Identification of genetic variants involved in the disease has no implication for clinical practice for the moment. The role of environmental factors, particularly endocrine disrupters, is plausible but not demonstrated. Literature review does not support the progression of endometriosis over time, either in terms of the volume or the number of the lesions (NP3). The risk of acute digestive occlusion or functional loss of a kidney in patients followed for endometriosis seems exceptional. These complications were revealing the disease in the majority of cases. IVF does not increase the intensity of pain associated with endometriosis (NP2). There is few data on the influence of pregnancy on the lesions, except the possibility of a decidualization of the lesions that may give them a suspicious aspect on imaging. The impact of endometriosis on pregnancy is debated. There is an epidemiological association between endometriosis and rare subtypes of ovarian cancer (endometrioid and clear cell carcinomas) (NP2). However, the relative risk is moderate (around 1.3) (NP2) and the causal relationship between endometriosis and ovarian cancer is not demonstrated so far. Considering the low incidence of endometriosis-associated ovarian cancer, there is no argument to propose a screening or a risk reducing strategy for the patients.

[Conventional analgesics and non-pharmacological multidisciplinary therapeutic treatment in endometriosis: CNGOF-HAS Endometriosis Guidelines]

A major symptom of endometriosis is pelvic pain with a wide range of intensity, rhythm, type, and expression, without clearly established relationship between pain and the disease. Endometriosis-associated pain has physical, psychological/behavioral and social consequences with a significant impact on patient quality-of-life in relation with the biopsychosocial model of chronic pain. Pain assessment in all of its dimensions, as well as assessing the consequences of pain is therefore a crucial part of therapeutic management. Conventional analgesics are commonly used although studies demonstrating their efficacy in the treatment of endometriosis-related pelvic pain are lacking. Non-steroid anti-inflammatory drugs (NSAIDs), known to be effective in dysmenorrhea unrelated to endometriosis, have not been recently re-assessed in patients with endometriosis. Following rigorous assessment, the characterization of neuropathic components of endometriosis-related pelvic pain may lead to treatment with antiepileptic of antidepressant drugs, although gabapentin and amitriptyline have yet to be specifically assessed in the setting of endometriosis-related pain. Other pharmacologically active compounds have been tested to treat endometriosis-related pain but did not demonstrate efficacy with sufficient level of evidence. Diets, dietary supplements and herbal medicine are often proposed and/or used as adjuncts without any conclusive evidence. Although the effects on endometriosis-related pain are methodologically difficult to assess, physical adjunctive therapies such as acupuncture, transcutaneous neurostimulation, osteopathy/chiropractics, physical therapy and physical activity, the long-term therapeutic relationship they establish may potentiate beneficial effects perceived by patients. However, it remains difficult to demonstrate significant effects of cognitive and/or behavioral interventions on endometriosis-related pain.

CONCLUSION

The complexity of managing endometriosis-related pain requires a holistic approach with sustained attention to the patient. Treatments, either pharmacologic or non-pharmacologic, including adjuvant therapies, associate a technical expertise to which a human approach must be added in order to bring value to these treatments. Multidisciplinary and/or inter disciplinary approaches are therefore essential to the care of patients suffering from endometriosis.

The Long-Term Footprint of Endometriosis: Population-Based Cohort Analysis Reveals Increased Pain Symptoms and Decreased Pain Tolerance at Age 46 Years

Previous studies have shown increased pain sensitivity in fertile-aged women with endometriosis in response to mechanical stimuli. As yet, population-based studies on the association of endometriosis with pain sensation and pain symptoms in late fertile age are lacking. The main objective of this population-based cohort study was to investigate whether a history of endometriosis is associated with altered pain sensation and musculoskeletal pain symptoms at age 46 years. Our data are derived from the Northern Finland Birth Cohort 1966, which contains postal questionnaire data (72% response rate) as well as clinical data assessing pressure-pain threshold and maximal pain tolerance. The study population consisted of 284 women with endometriosis and 3,390 controls. Our results showed that at age 46 women with a history of endometriosis had a 5.3% lower pressure-pain threshold and 5.1% lower maximal pain tolerance compared with controls. The most significant contributors besides endometriosis were anxiety, depression, and current smoking status. Women with endometriosis also reported an increased number of pain sites (0 pain sites, 9.6 vs 17.9%; 5-8 pain sites, 24.8 vs 19.1%, endometriosis vs controls respectively; P < .001), and their pain was more troublesome and intense. The results were adjusted for body mass index, smoking, depressive/anxiety symptoms, education, and use of hormonal contraceptives. These unique data revealed an altered pain sensation and a greater likelihood of reporting musculoskeletal pain at age 46 years among women with a history of endometriosis. The results imply that endometriosis has a long-term footprint on affected women, thus underlying the need for psychological support and medical treatment beyond fertile age.

PERSPECTIVE

This population-based cohort study showed decreased pain threshold and maximal pain tolerance in women with endometriosis in the late fertile age of 46 years. The pain was also found to be more bothersome and intense compared with controls.

Alterations in expression of endometrial milk fat globule-EGF factor 8 (MFG-E8) and leukemia inhibitory factor (LIF) in patients with infertility and endometriosis

OBJECTIVE

The aim of this study was to compare the endometrial expression of milk fat globule-EGF factor 8 (MFG-E8), its receptor integrin αvβ3, and leukemia inhibitory factor (LIF) in patients with endometriosis and infertility and in healthy fertile patients during the window of implantation.

METHODS

Five patients with peritoneal endometriosis and infertility (case group) and four healthy fertile patients (control group) were recruited. All patients were either diagnosed with or ruled out for endometriosis by laparoscopic surgery; the case group underwent surgery for infertility investigation and the control group for tubal ligation. Endometrial biopsies were performed in all patients during the window of implantation (LH+8 to LH+10), and then the samples were analyzed by immunochemistry for MFG-E8, integrin αvβ3, and LIF.

RESULTS

In patients with endometriosis and infertility, expression of MFG-E8 was significantly increased in the glandular epithelium when compared to healthy fertile patients (p<0.001). Moreover, LIF expression was lower in patients with endometriosis and infertility (p<0.05). Nevertheless, we found no difference in integrin αvβ3 expression between the groups (p=0.084).

CONCLUSION

This study showed for the first time that MFG-E8 expression is impaired in the endometrium of patients with endometriosis and infertility during the window of implantation. Moreover, LIF is also diminished in the endometrium of these patients as shown before.

The Role of Magnetic Resonance Imaging-Diffusion Tensor Imaging in Predicting Pain Related to Endometriosis: A Preliminary Study

OBJECTIVES

To evaluate the sacral nerve root features by the means of magnetic resonance imaging-diffusion tensor imaging (MRI-DTI) tractography in women with endometriosis and/or adenomyosis, and to analyze the correlations among DTI abnormalities, pain symptoms, and endometriotic lesions found at surgery.

DESIGN

A cross-sectional, observational study (Canadian Task Force classification II-2).

SETTING

University hospital.

PATIENTS

Women (n = 76) with clinical suspicion of endometriosis.

INTERVENTIONS

Before surgery, dysmenorrhea, deep dyspareunia, and noncyclic pelvic pain (NCPP) were assessed using a 10-point visual analog scale. MRI enabled a 3-dimensional reconstruction of S1, S2, and S3. Fractional anisotropy was calculated for each root. Laparoscopic treatment of endometriosis was performed in 56 patients.

MEASUREMENTS AND MAIN RESULTS

Our findings revealed correlations among sacral root reconstruction by MRI-DTI, pain symptoms, and laparoscopic findings. DTI of sacral roots revealed a regular and homogeneous appearance in 17 patients (25.8%) and abnormalities in microstructure reconstruction, with fiber irregularities and disorganization and loss of the simple unidirectional course, in 44 patients (66.7%). At laparoscopy, ovarian endometriomas were found in 82.1% of the patients, and deeply infiltrating endometriosis (DIE) were found in 57.1%. Endometriosis was staged according to the revised American Society for Reproductive Medicine classification. Pathological DTI findings were significantly associated with the severity of dysmenorrhea and NCPP, pain duration, presence of tubo-ovarian and cul-de-sac adhesions, and DIE.

CONCLUSION

The presence of pathological DTI findings of the sacral nerve roots correlates with the type of pain, adhesions, and DIE. At present, DTI can be useful for providing a better understanding of pain; however, DTI could become a useful tool in therapeutic planning for patients with endometriosis.

Pelvic floor muscle dysfunction on 3D/4D transperineal ultrasound in patients with deep infiltrating endometriosis: a pilot study

OBJECTIVE

Pelvic floor muscle (PFM) dysfunction seems to play an important role in the pathophysiology of pelvic pain, including that associated with deep infiltrating endometriosis (DIE). The aim of this study was to evaluate the static and dynamic morphometry of the PFM using three-dimensional (3D) and four-dimensional (4D) transperineal ultrasound in women with DIE compared with asymptomatic healthy women.

METHODS

This was a pilot, prospective study conducted at our tertiary center between March and November 2015. Fifty nulliparous women with DIE (study group) and 35 nulliparous asymptomatic healthy women (control group) were included. 3D/4D transperineal ultrasound examination of the PFM was performed in both groups. Levator hiatal area (LHA) and anteroposterior and left-right transverse diameters were evaluated at rest, on maximum PFM contraction and on maximum Valsalva maneuver. Persistent levator ani muscle (LAM) coactivation during Valsalva maneuver was investigated.

RESULTS

Compared with the control group, women with DIE had a smaller LHA at rest (P = 0.03) and during Valsalva maneuver (P < 0.01). Furthermore, reduction in LHA during PFM contraction (P < 0.001) and enlargement in LHA during Valsalva maneuver (P = 0.01) were significantly less marked. In comparison with controls, women with DIE presented a higher frequency of LAM coactivation during Valsalva maneuver, although this difference did not reach statistical significance (P = 0.05).

CONCLUSIONS

3D and 4D transperineal ultrasound is an objective and non-invasive method for PFM morphometry and may have a role in detecting PFM dysfunction in women with DIE. Copyright © 2016 ISUOG. Published by John Wiley & Sons Ltd.

Port site infiltration of local anesthetic after laparoendoscopic single site surgery for benign adnexal disease

Objective

To determine whether local bupivacaine injection into the incision site after gynecologic laparoendoscopic single site surgery (LESS) improves postoperative pain.

Methods

This prospective cohort study included consecutive 158 patients who had LESS for benign adnexal disease from March 2013 to December 2015. Chronologically, 82 patients (March 2013 to August 2014) received no bupivacaine (group 1) and 76 (August 2014 to December 2015) received a bupivacaine block (group 2). For group 2, 10 mL 0.25% bupivacaine was injected into the 20 mm-incision site through all preperitoneal layers after LESS completion. Primary outcome is postoperative pain score using the visual analog scale (VAS).

Results

There was no difference in clinicopathological characteristics between the groups. Operating time (expressed as median [range], 92 [55–222] vs. 100 [50–185] minutes, P=0.137) and estimated blood loss (50 [30–1,500] vs. 125 [30–1,000] mL, P=0.482) were similar between the groups. Post-surgical VAS pain scores after 3 hours (3.5 [2–6] vs. 3.5 [2–5], P=0.478), 6 to 8 hours (3.5 [2–6] vs. 3 [1–8], P=0.478), and 16 to 24 hours (3 [2–4] vs. 3 [1–7], P=0.664) did not differ between groups.

Conclusion

Bupivacaine injection into the trocar site did not improve postoperative pain after LESS. Randomized trials are needed to evaluate the benefits of local bupivacaine anesthetic for postoperative pain reduction.

Diagnostic Evaluation of Chronic Pelvic Pain

Chronic pelvic pain can result from various intra- and extra-pelvic etiologies. Although patient history and physical examination may narrow the differential diagnosis, frequently, the different etiologies have overlapping presentations. Imaging examinations such as US and/or MR imaging may help delineate the cause of pain, particularly when related to intra-pelvic organs, pelvic floor dysfunction or prolapse, synthetic material such as pelvic mesh or slings, and in some cases of neuropathic pain. Etiologies of neuropathic pain can also be assessed with non-imaging tests such as nerve conduction studies, electromyography, and testing of sacral reflexes.

The Clinical Significance of Endocannabinoids in Endometriosis Pain Management

Introduction: Patients with endometriosis often suffer from diffuse and poorly localized severe pain. The current pain management strategies include medical and hormonal therapy, as well as surgery. Medical management of pain is often insufficient and is associated with high rate of recurrence. Better pain management is therefore of urgent need. Methods: Among the various candidates, the endocannabinoid system (ECS) has recently emerged as a relevant pharmacological target for the management of endometriosis-related pain. A computerized literature search was performed to identify relevant studies combining the keywords "endometriosis," "endocannabinoid," "cannabinoid receptor," "THC," and "pain mechanisms." Conclusions: This review describes the multiple and complex pain mechanisms associated with endometriosis. Current data and theories concerning the link between the ECS and pain management for endometriosis patients are presented. Finally, we will discuss which aspects of endometriosis-associated pain can be targeted by modulation of the ECS.

Co-micronized Palmitoylethanolamide/Polydatin Treatment Causes Endometriotic Lesion Regression in a Rodent Model of Surgically Induced Endometriosis

Endometriosis is a chronic, painful disease characterized by the presence of endometrial glands and stroma outside the uterine cavity. Palmitoylethanolamide (PEA), an endogenous fatty acid amide, has anti-inflammatory and neuroprotective effects. PEA lacks free radical scavenging activity, unlike polydatin (PLD), a natural precursor of resveratrol. The aim of this study was to investigate the effect of orally administered co-micronized PEA/polydatin [m(PEA/PLD)] in an autologous rat model of surgically induced endometriosis. Endometriosis was induced in female Wistar albino rats by auto-transplantation of uterine squares (implants) into the intestinal mesentery and peritoneal cavity. Rats were distributed into one control group and one treatment group (10 animals each): m(PEA/PLD) 10 mg/kg/day. At 28 days after surgery the relative volume of the endometrioma was determined. Endometrial-like tissue was confirmed by histology: Masson trichrome and toluidine blue were used to detect fibrosis and mast cells, respectively. The treated group displayed a smaller cyst diameter, with improved fibrosis score and mast cell number decrease. m(PEA/PLD) administration decreased angiogenesis (vascular endothelial growth factor), nerve growth factor, intercellular adhesion molecule, matrix metalloproteinase 9 expression, and lymphocyte accumulation. m(PEA/PLD) treatment also reduced peroxynitrite formation, (poly-ADP)ribose polymerase activation, IkBα phosphorylation and nuclear facor-kB traslocation in the nucleus. Our results suggested that m(PEA/PLD) may be of use to inhibit development of endometriotic lesions in rats.

Innovative approach in assessing the role of neurogenesis, angiogenesis, and lymphangiogenesis in the pathogenesis of external genital endometriosis

Endometriosis is a chronic, progressive, relapsing estrogen-dependent disorder characterized by the growth of tissue structure and function similar to the endometrium outside the normal mucosa of the uterine cavity localization. Endometriosis is found in 10-15% of women in reproductive age and it is one of the main causes of pelvic pain syndrome and infertility. Mechanisms of the development of endometriosis and related pathological pain impulses are still poorly understood and therapeutic approaches do not always have a sufficient effect; in this connection, the study of the pathogenesis of endometriosis and endometriosis-associated pain currently is perspective. Identification of significant factors of angiogenesis, lymphangiogenesis, and neurogenesis in the external genital endometriosis will promote the development of non-invasive early diagnosis and pathogenetic therapy.

Ultrastructural Investigation of Pelvic Peritoneum in Patients With Chronic Pelvic Pain and Subtle Endometriosis in Association With Chromoendoscopy

STUDY OBJECTIVE

To evaluate the pelvic peritoneum under chromoendoscopy by scanning electron microscopy (SEM) as well as light microscopy with hematoxylin and eosin staining and immunohistochemistry (IHC) assays in patients with chronic pelvic pain (CPP) associated with subtle endometriosis.

DESIGN

Case series study (Canadian Task Force classification II).

SETTING

A referral academic community tertiary medical center.

PATIENTS

Three women aged 29 to 37 years were referred to the obstetrics and gynecology clinic of the tertiary university hospital with CPP. They were suspicious for endometriosis, were not responding to medical treatments, and had undergone previous pelvic laparoscopy to determine the stage of endometriosis and preparation of peritoneal samples under the guidance of staining with methylene blue in 0.25% dilution.

INTERVENTIONS

Comparison of stained and unstained pelvic peritoneal samples after the instillation of 0.25% methylene blue into the pelvic cavity.

MEASUREMENTS AND MAIN RESULTS

In 3 patients, laparoscopic examination showed minimal endometriosis. A total of 18 samples (9 stained and 9 unstained) from the 3 patients were prepared for SEM. Ten of the samples (55.6%) showed microstructural peritoneal destruction (7 of 9 stained [77.7%] and 3 of 9 [33.4%] unstained). Eighteen samples (9 stained and 9 unstained) from the 3 patients were also prepared for IHC. Six of these samples (33.3%) were S-100-positive, including 4 of 9 (44.4%) stained samples and 2 of 9 (22.2%) unstained samples.

CONCLUSIONS

In general, in the context of CPP and endometriosis, there is no established relationship between the severity of pain and stage of endometriosis. In the pathophysiology of CPP associated with endometriosis, ultrastructural changes can play a significant role. Under methylene blue staining, some destroyed areas were detected, but the stained areas do not necessarily correlate with increased microstructural peritoneal destruction.

Endometriosis-Derived Thromboxane A2 Induces Neurite Outgrowth

Hyperinnervation in endometriosis is now well documented, but so far only a few neurotrophins have been identified. Since endometriotic stromal cells secrete thromboxane A2 (TXA₂), we sought to determine whether TXA₂, derived from endometriotic stromal cells, induces neurite outgrowth. Using primary sensory neurons derived from rat dorsal root ganglia (DRG) and ectopic endometrial stromal cells (EESCs) derived from human ovarian endometrioma tissues, we treated the primary neurons with different concentrations of U-46619, a stable TXA₂ mimetic, and performed a neuronal growth assay. The primary neurons were also cocultured with a vehicle, nerve growth factor (NGF, serving as a positive control), the supernatant of EESC culture medium, or the supernatant of EESCs pretreated with ozagrel, a thromboxane synthase inhibitor, and a neuronal growth assay was performed. The total neurite length was evaluated through immunofluorescence microscopy. We found that U-46619 significantly increased the neurite outgrowth in DRG neurons in a concentration-dependent fashion ( P < .001). It also increased the number of neurite ends in a concentration-dependent fashion. Ozagrel treatment alone had no effect on the neurite growth ( P > .05), and the treatment with the supernatant of EESCs induced neurite outgrowth just as potently as that treated with NGF (positive control; P > .05). Remarkably, treatment with the EESC supernatant increased the neurite outgrowth by nearly 3-fold as compared with the control ( P < .01), but the pretreatment with ozagrel abolished the stimulatory effect of the EESC by 31.3% ( P < .05). These findings indicate that EESCs potently induce neurite outgrowth, and endometriosis-derived TXA₂ is responsible, at least in part, for this neurotrophic effect.

Evaluation of the sacral nerve plexus in pelvic endometriosis by three-dimensional MR neurography

PURPOSE

To investigate the feasibility of three-dimensional MR neurography (3D MRN) for the sacral plexus using sampling perfection with application-optimized contrasts using different flip angle evolution (SPACE) sequences, and to demonstrate structural abnormalities in the pelvic nerve of women with pelvic endometriosis.

MATERIALS AND METHODS

Twenty patients with pelvic endometriosis and 20 healthy controls were examined by contrast-enhanced 3D short time inversion recovery T2-weighted imaging (CE 3D STIR T2WI) SPACE sequences on 3 Tesla MRI. Image quality and diagnostic confidence of the sequences in identifying abnormalities of the sacral plexus were analyzed and compared with conventional three-plane images of 2D turbo-spin echo T2-weighted images (2D TSE T2WI). The changes in the sacral plexus caused by endometrial lesions were evaluated.

RESULTS

The sacral plexus was clearly revealed in both healthy controls and patients with endometriosis on 3D STIR SPACE images. A good agreement was reached in the evaluation of both imaging quality (Kappa value [κ] = 0.73-1.00) and diagnostic confidence (κ = 0.66-0.81) when compared between the two independent readers. Abnormalities caused by endometriosis were identified in 17 patients, unilaterally in 10 patients, and bilaterally in 7 patients. Nerve fiber abnormalities of lumbar 5 (L5) were detected in 11 patients, of sacral 1 (S1) in 14 patients and of sacral 2 (S2) in 9 patients.

CONCLUSION

CE 3D STIR SPACE sequences demonstrate its significant capacity to investigate and map the sacral plexus, and reveal the compression and adhesion of the sacral plexus nerve as a result of ectopic lesions.

LEVEL OF EVIDENCE

3 J. Magn. Reson. Imaging 2017;45:1225-1231.

Nerve fibers and endometriotic lesions: partners in crime in inflicting pains in women with endometriosis

One of major objectives in treating endometriosis is to alleviate pain since dysmenorrhea and other types of pain top the list of complaints from women with endometriosis who seek medical attention. Indeed, endometriosis-associated pain (EAP) is the most debilitating of the disease that negatively impacts on the quality of life in affected women, contributing significantly to the burden of disease and adding to the substantial personal and societal costs. Unfortunately, the mechanisms underlying the EAP are still poorly understood. In the last two decades, one active research field in endometriosis is the investigation on the distribution and genesis of nerve fibers in eutopic and ectopic endometrium, and the attempt to use endometrial nerve fiber density for diagnostic purpose. Since EAP presumably starts with the terminal sensory nerves, in or around endometriotic lesions, that transduce noxious mediators to the central nervous system (CNS) which ultimately perceives pain, this field of research holds the promise to elucidate the molecular mechanisms underlying the EAP, thus opening new avenues for novel diagnostics and therapeutics. In this review, we shall first briefly provide some basic facts on nerve fibers, and then provide an overview of some major findings in this filed while also note some conflicting results and expose areas in need of further research. We point out that since recently accumulated evidence suggests that endometriotic lesions are wounds undergoing repeated tissue injury and repair, the relationship between endometriotic lesions and nerve fibers is not simply unidirectional, i.e. lesions promote hyperinnervations. Rather, it is bidirectional, i.e. endometriotic lesions and nerve fibers engage active cross-talks, resulting in the development of endometriosis and pain. That is, nerve fibers and endometriotic lesions are actually partners in crime in inflicting pains in women with endometriosis, aided and abetted possibly by other culprits, some yet to be identified. We provide a list of possible perpetrators likely to be involved in this crime. Finally, we discuss possible implications when viewing the relationship from this vista.

[Morphological substrate and pathogenetic mechanisms of pelvic pain syndrome in endometriosis. Part II. Peripheral nerve tissue remodeling in the foci of endometriosis]

Endometriosis (EM) is morphologically characterized by the development of extrauterine endometrioid heterotopies, the major clinical symptoms of which is chronic pelvic pain, which is a serious problem not only in modern gynecology, but also in public health as a whole.

AIM

to investigate neurogenic markers in the foci of EM of various sites and histological structure in women with and without pain syndrome.

MATERIAL AND METHODS

The investigation was performed using the operative material (resected segments of the intestine, bladder, rectovaginal septum, and small pelvic peritoneum) obtained from 52 women with an intraoperative and morphologically verified diagnosis of EM and (Group 1) and without (Group 2) pain syndrome. Immunohistochemical examination was made on paraffin-embedded tissue sections in accordance with the standard protocols, by using the antibodies: 1) anti-PGP 9.5 polyclonal rabbit antibodies; 2) mouse anti-human neurofilament (NF) protein monoclonal antibodies (Clone 2F1); 3) mouse anti-nerve growth factor (NGF) monoclonal antibodies; 4) monoclonal mouse anti-human NGF receptor p75 (NGFRp75) antibodies (Dako, Denmark).

RESULTS

Our findings demonstrate differences in the expression of PGP 9.5, NFs, NGF, and NGFRp75 in the foci and adjacent tissue in painful and painless EM irrespective of the locations of heterotopies.

CONCLUSION

The found molecular features are a manifestation of the remodeling of nerve fibers and nerve endings in the foci of EM and PGP9.5, NGF, and NGFRp75 give rise to nerve fiber neoformation and pain syndrome in EM. At the same time, the immunohistochemical phenotype of EM foci does not depend on their site and reflects the presence or absence of pain syndrome.

Elevated Systemic Levels of Endocannabinoids and Related Mediators Across the Menstrual Cycle in Women With Endometriosis

Cannabinoids and modulators of the endocannabinoid system affect specific mechanisms that are critical to the establishment and development of endometriosis. The aim of this study was to measure the systemic levels of endocannabinoids and related mediators in women with and without endometriosis and to investigate whether such levels correlated with endometriosis-associated pain. Plasma and endometrial biopsies were obtained from women with a laparoscopic diagnosis of endometriosis (n = 27) and no endometrial pathology (n = 29). Plasma levels of endocannabinoids (N-arachidonoylethanolamine [AEA] and 2-arachidonoylglycerol [2-AG]) and related mediators (N-oleoylethanolamine [OEA] and N-palmitoylethanolamine [PEA]), messenger RNA expression of some of their receptors (cannabinoid receptor type 1 [CB1], CB2, transient receptor potential vanilloid type [TRPV1]), and the enzymes involved in the synthesis (N-acyl-phosphatidylethanolamine-hydrolyzing phospholipase D [NAPE-PLD]) and degradation (fatty acid amide hydrolase 1 [FAAH]) of AEA, OEA, and PEA were evaluated in endometrial stromal cells. The systemic levels of AEA, 2-AG, and OEA were elevated in endometriosis in the secretory phase compared to controls. The expression of CB1 was higher in secretory phase endometrial stromal cells of controls versus endometriosis. Similar expression levels of CB2, TRPV1, NAPE-PLD, and FAAH were detected in controls and endometriosis. Patients with moderate-to-severe dysmenorrhea and dyspareunia showed higher AEA and PEA levels than those with low-to-moderate pain symptoms, respectively. The association of increased circulating AEA and 2-AG with decreased local CB1 expression in endometriosis suggests a negative feedback loop regulation, which may impair the capability of these mediators to control pain. These preliminary data suggest that the pharmacological manipulation of the action or levels of these mediators may offer an alternative option for the management of endometriosis-associated pain.

Sciatic endometriosis induces mechanical hypersensitivity, segmental nerve damage, and robust local inflammation in rats

BACKGROUND

Endometriosis is a common cause of pain including radicular pain. Ectopic endometrial tissue may directly affect peripheral nerves including the sciatic, which has not been modelled in animals.

METHODS

We developed a rat model for sciatic endometriosis by grafting a piece of autologous uterine tissue around the sciatic nerve. Control animals underwent a similar surgery but received a graft of pelvic fat tissue.

RESULTS

The uterine grafts survived and developed fluid-filled cysts; the adjacent nerve showed signs of swelling and damage. Mechanical and cold hypersensitivity and allodynia of the ipsilateral hindpaw developed gradually over the first 2 weeks after the surgery, peaked at 2-5 weeks, and was almost resolved by 7 weeks. Control animals showed only minor changes in these pain behaviours. Histological signs of inflammation in the uterine graft and in the adjacent nerve were observed at 3 weeks but were resolving by 7 weeks. In vivo fibre recording showed increased spontaneous activity, especially of C-fibres, in sciatic nerve proximal to the uterine graft. Several pro-inflammatory cytokines including interluekin-18, VEGF, fractalkine, and MIP-1α, were elevated in the uterine graft plus sciatic nerve samples, compared to samples from normal nerve or nerve plus fat graft. Growth associated protein 43 (GAP43), a marker of regenerating nerve fibres, was observed in the adjacent sciatic nerve as well as in the uterine graft.

CONCLUSIONS

This model shared many features with other rat models of endometriosis, but also had some unique features more closely related to neuropathic pain models.

WHAT DOES THIS STUDY/REVIEW ADD

Some especially painful forms of endometriosis are essentially neuropathic, because peripheral nerves are directly affected by nearby ectopic endometrial tissue. We modelled endometriosis by implanting autologous uterine tissue around rat sciatic nerve. We observed mechanical and cold pain behaviours along with signs of inflammation and nerve damage and increased pro-inflammatory cytokines at the implant site. Pain behaviours correlated with signs of nerve inflammation and damage rather than with cyst survival.

Elagolix, a novel, orally bioavailable GnRH antagonist under investigation for the treatment of endometriosis-related pain

Suppression of estrogen production and reduction of menstrual blood flow are the mainstays of medical treatment of endometriosis-related pain and have been traditionally achieved by methods such as combined hormonal contraception, progestins and GnRH analogs, all with comparable efficacies, though different side-effect profiles. Elagolix is the frontrunner among an emerging class of GnRH antagonists, which unlike their peptide predecessors has a nonpeptide structure resulting in its oral bioavailability. Phase I and II clinical trials have demonstrated safety of elagolix and its efficacy in partial and reversible suppression of ovarian estrogen production resulting in improvements in endometriosis-related pain. Phase III clinical trials are currently underway and elagolix may become a valuable addition to the armamentarium of pharmacological agents to treat endometriosis-related pain.

Association of chronic pelvic pain and endometriosis with signs of sensitization and myofascial pain

OBJECTIVE

To evaluate sensitization, myofascial trigger points, and quality of life in women with chronic pelvic pain with and without endometriosis.

METHODS

A cross-sectional prospective study of women aged 18-50 years with pain suggestive of endometriosis and healthy, pain-free volunteers without a history of endometriosis. Patients underwent a physiatric neuromusculoskeletal assessment of clinical signs of sensitization and myofascial trigger points in the abdominopelvic region. Pain symptoms, psychosocial, and quality-of-life measures were also assessed. All participants with pain underwent laparoscopic excision of suspicious lesions to confirm endometriosis diagnosis by histologic evaluation.

RESULTS

Patients included 18 with current, biopsy-proven endometriosis, 11 with pain only, and 20 healthy volunteers. The prevalence of sensitization as measured by regional allodynia and hyperalgesia was similar in both pain groups (83 and 82%) but much lower among healthy volunteers (15%, P<.001). Nearly all women with pain had myofascial trigger points (94 and 91%). Adjusting for study group, those with high anxiety (odds ratio [OR] 1.05, 95% confidence interval [CI] 1.004-1.099, P=.031) and depression (OR 1.06, 95% CI 1.005-1.113, P=.032) scores were more likely to have sensitization. Pain patients with any history of endometriosis had the highest proportion of sensitization compared with the others (87% compared with 67% compared with 15%; P<.001). Adjusting for any history of endometriosis, those with myofascial trigger points were most likely sensitized (OR 9.41, 95% CI 1.77-50.08, P=.009).

CONCLUSION

Sensitization and myofascial trigger points were common in women with pain regardless of whether they had endometriosis at surgery. Those with any history of endometriosis were most likely to have sensitization. Traditional methods of classifying endometriosis-associated pain based on disease, duration, and anatomy are inadequate and should be replaced by a mechanism-based evaluation, as our study illustrates.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov, www.clinicaltrials.gov, NCT00073801.

LEVEL OF EVIDENCE

II.

LH (Trp8Arg/Ile15Thr), LHR (insLQ) and FSHR (Asn680Ser) polymorphisms genotypic prevalence in women with endometriosis and infertility

PURPOSE

To verify if polymorphisms of LH (Trp8Arg/Ile15Thr), LH receptor (insLQ), and FSH receptor (Asn680Ser) are associated with endometriosis and infertility.

METHODS

This is a prospective case-control study. Sixty-seven patients with endometriosis and infertility (study group) and 65 healthy fertile patients (control group) were enrolled in the study between July 2010 and July 2013. All patients had their endometriosis diagnosis made or excluded by laparoscopic surgery; study group was submitted to the surgery for infertility investigation and control group for tubal ligation. Day-3 serum hormones were collected from all patients. Analysis of nucleotide mutations for LH polymorphisms (Trp8Arg and Ile15Thr), LHR polymorphism (insLQ), and FSHR polymorphism (Asn680Ser) were performed by PCR.

RESULTS

Day-3 FSH, estradiol and LH serum levels were not different between the groups, while CA-125 was higher in patients with endometriosis and infertility. All polymorphisms studied were in Hardy-Weinberg equilibrium. The prevalence of insLQ was significantly higher in patients with endometriosis and infertility (P = 0.005). Allele occurrence in control group was 0.10 versus 0.25 in infertile endometriosis group (P = 0.001). There was no difference regarding Trp8Arg/Ile15Thr (P > 0.05) and Asn680Ser (P > 0.05) prevalence between groups.

CONCLUSION

This is the first time that prevalence of insLQ was shown to be higher in patients with endometriosis and infertility than in healthy fertile patients. There was no difference in LH and FSHR polymorphisms' prevalence between groups.

[The morphological substrate and pathogenetic mechanisms of pelvic pain syndrome in endometriosis]

OBJECTION

To study the origin and morphological substrate of pain syndrome in deep infiltrating endometriosis involving the bowel.

SUBJECTS AND METHODS

The investigation was conducted using the intraoperative material (resected portions of the large and small bowels, appendix) obtained from 40 women diagnosed as having deep infiltrating endometriosis involving the bowel, which was accompanied by pain syndrome. Paraffin sections were immunohistochemically examined using the standard protocol. Antibodies to Ki-67, PTEN, ER, PR, ("Dako"), CD34 ("Cell Marque", USA), VEGF, EGF, EGFR, COX-2 ("Abcam"), and MMP 1 and 2 ("Abbiotec") were applied. Dako REAL EnVision Detection System kits ("Dako", Denmark) were used as secondary antibodies.

RESULTS

The morphological substrate of pelvic pain syndrome in deep infiltrating endometriosis was established to be factors that acted in situ at the location of endometriotic foci and those caused by the infiltrative perivascular, intravascular, and perineural growth of endometrioid heterotopies.

CONCLUSION

Inflammation and fibrosis in the endometriotic foci contribute to the accumulation of algogenes, which gives rise to somatogenic pain syndrome, and chronic nerve fiber injury as a source of nociceptive stimulation leads to neuropathic pain syndrome.

Current strategies for endometriosis management

Endometriosis is a common gynecologic disorder that persists throughout the reproductive years. Although endometriosis is a surgical diagnosis, medical management with ovarian suppression remains the mainstay of long-term management with superimposed surgical intervention when needed. The goal of surgery should be excision or ablation of all visible disease to minimize risk of recurrence and need for repeat surgeries. When infertility is the presenting symptom, surgical therapy in addition to assisted reproductive technology can improve chances of conception; however, the treatment approach depends on stage of disease and other patient characteristics that affect fecundity.

Does the uterine cervix become abnormally reinnervated after subtotal hysterectomy and what is the association with future trachelectomy?

STUDY OBJECTIVE

To compare nerve fiber density in the cervices removed by trachelectomy from women with pelvic pain with those cervices removed for nonpain indications.

DESIGN

Retrospective cohort study (Canadian Task Force classification II-2).

SETTING

Two university hospitals.

PATIENTS

Subjects who underwent trachelectomy during a 10-year time frame were identified.

INTERVENTIONS

Two tissue sections were obtained from each preserved cervix specimen and stained for S100 antibody. The numbers of S100-immunoreactive peripheral nerve fibers were assessed in 6 high-powered fields (HPFs) per tissue section (12 total HPFs per patient). Information collected included patient characteristics and surgical findings. We excluded any patients with dysplasia/cancer and those without an available adequate specimen.

MEASUREMENTS AND MAIN RESULTS

We evaluated the cervix specimens from 35 patients who underwent trachelectomy for pain (n = 25, group 1) and nonpain (n = 10, group 2) indications in addition to control cervices (n = 15, group 3) from benign hysterectomies performed for nonpain indications. There were increased numbers of nerve fibers in trachelectomy patients with pain versus those without pain (group 1 vs group 2, p = .02). There were also increased numbers of nerve fibers in both trachelectomy groups compared with the control group (group 1 vs group 3, p < .01; group 2 vs group 3, p = .04). Adjusted average cervical nerve counts/HPF were 17.8 (95% confidence interval [CI], 13.2-22.3) for pain-indicated trachelectomies, 11.5 (95% CI, 4.8-18.2) for nonpain, and 6.3 (95% CI, 0.8-11.8) for controls. Regardless of trachelectomy indication, adjusted average nerve counts/HPF were 17.7 (95% CI, 13.4-22.0) for patients with endometriosis and 14.6 (95% CI, 12.2-17.1) for patients without endometriosis.

CONCLUSION

Nerve fibers in the cervical stump after supracervical hysterectomy are significantly increased in women undergoing trachelectomy for pain indications compared with those who underwent trachelectomy for nonpain indications and controls. Although not statistically significant, endometriosis may be an independent risk factor for increased nerve fibers. These histopathologic observations may support the idea that the cervix should be removed in women undergoing hysterectomy for chronic pelvic pain or endometriosis.