An evidence-based medicine approach to the treatment of endometriosis-associated chronic pelvic pain: placebo-controlled studies

Correlation between Anatomopathological Aspects and Pelvic Pain in Women with Deep Infiltrating Endometriosis

OBJECTIVE

 To correlate the morphological aspects with pelvic pain in women with deep infiltrating endometriosis.

METHODS

 A retrospective study with 67 women with deep endometriosis who underwent surgical treatment in a tertiary hospital from 2007 to 2017. The following variables were considered: age, parity, body mass index, site of involvement, hormonal treatment before surgery, pelvic pain, and morphometric analysis. The histological slides of the surgical specimens were revised and, using the ImageJ software for morphometric study, the percentages of stromal/glandular tissues were calculated in the histological sections.

RESULTS

 The mean age of the women was 38.9 ± 6.5 years. The mean pain score was 8.8 ± 1.9 and the mean time of symptomatology was 4.7 ± 3.5 years, with 87% of the patients undergoing hormone treatment prior to surgery. The average expression of CD10, CK7, and S100 markers was 19.5 ± 11.8%, 9.4 ± 5.9%, and 7.9 ± 5.8% respectively. It was found that the greater the expression of CD10, the greater the level of pain (p = 0.02). No correlation was observed between the expression of CD10, CK7, and S100 markers and age and duration of symptoms.

CONCLUSION

 Women with deep infiltrating endometriosis have a positive association between the level of pain and the fibrosis component in the endometrial tissue's histological composition.

Endometriosis and Opioid Receptors: Are Opioids a Possible/Promising Treatment for Endometriosis?

Endometriosis (EM), defined as the presence of endometrial-like tissue with surrounding smooth muscle cells outside the uterus, is a disregarded gynecological disease reported to affect 6-10% of women of reproductive age, with 30-50% of them suffering from chronic pelvic pain and infertility. Since the exact pathogenic mechanisms of EM are still unclear, no curative therapy is available. As pain is an important factor in EM, optimal analgesia should be sought, which to date has been treated primarily with non-steroidal anti-inflammatory drugs (NSAIDs), metamizole or, in extreme cases, opioids. Here, we review the pain therapy options, the mechanisms of pain development in EM, the endogenous opioid system and pain, as well as the opioid receptors and EM-associated pain. We also explore the drug abuse and addiction to opioids and the possible use of NOP receptors in terms of analgesia and improved tolerability as a target for EM-associated pain treatment. Emerging evidence has shown a promising functional profile of bifunctional NOP/MOP partial agonists as safe and nonaddictive analgesics. However, until now, the role of NOP receptors in EM has not been investigated. This review offers a thought which still needs further investigation but may provide potential options for relieving EM-associated pain.

A syngeneic inoculation mouse model of endometriosis that develops multiple comorbid visceral and cutaneous pain like behaviours

ABSTRACT

Endometriosis is a chronic and debilitating condition, commonly characterised by chronic pelvic pain (CPP) and infertility. Chronic pelvic pain can be experienced across multiple pelvic organs, with comorbidities commonly effecting the bowel, bladder, and vagina. Despite research efforts into endometriosis pathophysiology, little is known about how endometriosis induces CPP, and as such, therapeutic interventions are lacking. The aim of this study was to characterise a syngeneic mouse model of endometriosis that mimics naturally occurring retrograde menstruation, thought to precede endometriosis development in patients, and determine whether these mice exhibit signs of CPP and altered behaviour. We characterised the development of endometriosis over 10 weeks following uterine tissue inoculation, measured in vivo and ex vivo hypersensitivity to mechanical stimuli across multiple visceral organs, and assessed alterations in animal spontaneous behaviour. We confirmed that inoculated uterine horn tissue formed into endometriosis lesions throughout the peritoneal cavity, with significant growth by 8 to 10 weeks post inoculation. Additionally, we found that mice with fully developed endometriosis displayed hypersensitivity evoked by (1) vaginal distension, (2) colorectal distension, (3) bladder distension, and (4) cutaneous thermal stimulation, compared to their sham counterparts. Moreover, endometriosis mice displayed alterations in spontaneous behaviour indicative of (5) altered bladder function and (6) anxiety. This model creates a foundation for mechanistical studies into the diffuse CPP associated with endometriosis and the development of targeted therapeutic interventions to improve the quality of life of women with endometriosis.

Clinical Management of Chronic Pelvic Pain in Endometriosis Unresponsive to Conventional Therapy

Background: Although several treatments are currently available for chronic pelvic pain, 30–60% of patients do not respond to them. Therefore, these therapeutic options require a better understanding of the mechanisms underlying endometriosis-induced pain. This study focuses on pain management after failure of conventional therapy. Methods: We reviewed clinical data from 46 patients with endometriosis and chronic pelvic pain unresponsive to conventional therapies at Puerta de Hierro University Hospital Madrid, Spain from 2018 to 2021. Demographic data, clinical and exploratory findings, treatment received, and outcomes were collected. Results: Median age was 41.5 years, and median pain intensity was VAS: 7.8/10. Nociceptive pain and neuropathic pain were identified in 98% and 70% of patients, respectively. The most common symptom was abdominal pain (78.2%) followed by pain with sexual intercourse (65.2%), rectal pain (52.1%), and urologic pain (36.9%). A total of 43% of patients responded to treatment with neuromodulators. Combined therapies for myofascial pain syndrome, as well as treatment of visceral pain with inferior or superior hypogastric plexus blocks, proved to be very beneficial. S3 pulsed radiofrequency (PRF) plus inferior hypogastric plexus block or botulinum toxin enabled us to prolong response time by more than 3.5 months. Conclusion: Treatment of the unresponsive patient should be interdisciplinary. Depending on the history and exploratory findings, therapy should preferably be combined with neuromodulators, myofascial pain therapies, and S3 PRF plus inferior hypogastric plexus blockade.

A mouse model of endometriosis that displays vaginal, colon, cutaneous, and bladder sensory comorbidities

Endometriosis is a painful inflammatory disorder affecting ~10% of women of reproductive age. Although chronic pelvic pain (CPP) remains the main symptom of endometriosis patients, adequate treatments for CPP are lacking. Animal models that recapitulate the features and symptoms experienced by women with endometriosis are essential for investigating the etiology of endometriosis, as well as developing new treatments. In this study, we used an autologous mouse model of endometriosis to examine a combination of disease features and symptoms including: a 10 week time course of endometriotic lesion development; the chronic inflammatory environment and development of neuroangiogenesis within lesions; sensory hypersensitivity and altered pain responses to vaginal, colon, bladder, and skin stimulation in conscious animals; and spontaneous animal behavior. We found significant increases in lesion size from week 6 posttransplant. Lesions displayed endometrial glands, stroma, and underwent neuroangiogenesis. Additionally, peritoneal fluid of mice with endometriosis contained known inflammatory mediators and angiogenic factors. Compared to Sham, mice with endometriosis displayed: enhanced sensitivity to pain evoked by (i) vaginal and (ii) colorectal distension, (iii) altered bladder function and increased sensitivity to cutaneous (iv) thermal and (v) mechanical stimuli. The development of endometriosis had no effect on spontaneous behavior. This study describes a comprehensive characterization of a mouse model of endometriosis, recapitulating the clinical features and symptoms experienced by women with endometriosis. Moreover, it delivers the groundwork to investigate the etiology of endometriosis and provides a platform for the development of therapeutical interventions to manage endometriosis-associated CPP.

Pain in Endometriosis

Endometriosis is a chronic and debilitating condition affecting ∼10% of women. Endometriosis is characterized by infertility and chronic pelvic pain, yet treatment options remain limited. In many respects this is related to an underlying lack of knowledge of the etiology and mechanisms contributing to endometriosis-induced pain. Whilst many studies focus on retrograde menstruation, and the formation and development of lesions in the pathogenesis of endometriosis, the mechanisms underlying the associated pain remain poorly described. Here we review the recent clinical and experimental evidence of the mechanisms contributing to chronic pain in endometriosis. This includes the roles of inflammation, neurogenic inflammation, neuroangiogenesis, peripheral sensitization and central sensitization. As endometriosis patients are also known to have co-morbidities such as irritable bowel syndrome and overactive bladder syndrome, we highlight how common nerve pathways innervating the colon, bladder and female reproductive tract can contribute to co-morbidity via cross-organ sensitization.

Adverse Childhood Experiences Among Gynecology Patients With Chronic Pelvic Pain

OBJECTIVE

To compare adverse childhood experiences (ACEs) in women with chronic pelvic pain with a control group, and describe occurrence of specific ACEs in women with chronic pelvic pain.

METHODS

This case-control study examined the relationship between history of ACEs, traumatic events occurring during childhood as defined by the Centers for Disease Control and Prevention (CDC), and chronic pelvic pain. Patients diagnosed with chronic pelvic pain (n=60) were age-matched to a control group of women without chronic pelvic pain (n=60). All participants completed validated measures to detect for presence of any of the 11 ACEs as identified by the CDC's Behavioral Risk Factor Surveillance System ACE Module.

RESULTS

Mean participant age was 40 (±11 years). Total numbers of ACEs were elevated in chronic pelvic pain participants compared with a control group (median 4 [interquartile range 2-6] vs median 1 [interquartile range 0-4], P<.001) and 53% of chronic pelvic pain participants had four or more ACEs, compared with 27% of the control group (odds ratio [OR] 3.14; 95% CI 1.46-6.75). All categories of abuse were more prevalent in chronic pelvic pain compared with the control group: physical (43% vs 15%, OR 4.3; 95% CI 1.8-10.4; P=.001), sexual (55% vs 23%, OR 4.0; 95% CI 1.8-8.8; P<.001) and verbal or emotional (62% vs 33%, OR 3.2; 95% CI 1.5-6.8; P=.003). Regarding household challenges, the subcategory most prevalent in chronic pelvic pain participants compared with the control group was that of witnessed domestic violence (35% vs 8%, OR 5.9; 95% CI 2.1-17.1, P<.001).

CONCLUSION

Chronic pelvic pain participants had a greater than threefold odds of having a history of childhood abuse and having witnessed domestic violence during childhood compared with the control group. Women with chronic pelvic pain had increased numbers of ACEs and 53% had four or more ACEs, crossing a threshold that others have found to predict poor overall health outcomes.

Safety and efficacy of ilioinguinal and iliohypogastric nerve blocks for treatment of pelvic pain

Objective:

To assess the safety and efficacy of ilioinguinal/iliohypogastric nerve blocks for patients with lower abdominal wall pain in a gynaecology setting.

Methods:

A retrospective chart review of 131 patients who received ilioinguinal/iliohypogastric nerve blocks at a tertiary referral centre for pelvic pain between 1 January 2012 and 13 July 2017 was performed. Patient demographics, history, examination findings and block data were extracted. Chi-square and Mann–Whitney U tests explored differences in patient characteristics between patients with and without effective response to their initial ilioinguinal/iliohypogastric nerve block.

Results:

A total of 465 ilioinguinal/iliohypogastric nerve blocks were performed among patients. The effect of the initial block was available for 99 out of 131 patients. Of these patients, 70% (n = 69) reported a great improvement in pain, 9% (n = 9) some improvement in pain, 18% (n = 18) no response and 3% (n = 3) worsening of pain. A significantly greater number of patients who were not responsive to their first block reported unilateral pain (p = 0.040) and had a history of vulvodynia (p = 0.038) when compared to patients who were responsive to their first block. Seven patients (5%) reported minor adverse events related to blocks.

Conclusion:

Ilioinguinal/iliohypogastric nerve blocks provide pain relief for those with pelvic pain localized to the lower abdominal wall, with a low rate of minor adverse events.

Reevaluating response and failure of medical treatment of endometriosis: a systematic review

Objective

To assess patient response rates to medical therapies used to treat endometriosis-associated pain.

Design

A systematic review with the use of Medline and Embase.

Setting

Not applicable.

Patient(s)

Women receiving medical therapy to treat endometriosis.

Interventions(s)

None.

Main Outcome Measure(s)

The proportions of patients who: experienced no reduction in endometriosis-associated pain symptoms; had pain symptoms remaining at the end of the treatment period; had pain recurrence after treatment cessation; experienced an increase or no change in disease score during the study; were satisfied with treatment; and discontinued therapy owing to adverse events or lack of efficacy. The change in pain symptom severity experienced during and after treatment, as measured on the visual analog scale, was also assessed.

Result(s)

In total, 58 articles describing 125 treatment arms met the inclusion criteria. Data for the response of endometriosis-associated pain symptoms to treatment were presented in only 29 articles. The median proportions of women with no reduction in pain were 11%–19%; at the end of treatment, 5%–59% had pain remaining; and after follow-up, 17%–34% had experienced recurrence of pain symptoms after treatment cessation. After median study durations of 2–24 months, the median discontinuation rates due to adverse events or lack of efficacy were 5%–16%.

Conclusion(s)

Few studies of medical therapies for endometriosis report outcomes that are relevant to patients, and many women gain only limited or intermittent benefit from treatment.

National German Guideline (S2k): Guideline for the Diagnosis and Treatment of Endometriosis: Long Version - AWMF Registry No. 015-045

In this guideline, recommendations and standards for optimum diagnosis and treatment of endometriosis are presented. They are based on the analysis of the available scientific evidence as published in prospective randomized and retrospective studies as well as in systematic reviews. The guideline working group consisted of experts from Austria, Germany, Switzerland, and the Czech Republic.

Centering as a model for group visits among women with chronic pelvic pain

Providing comprehensive care for chronic pelvic pain is impeded by time and resource constraints of the standard health care visit. To provide patient education, psychosocial support, and health care assessment, we developed group visits for women with chronic pelvic pain using an evidence-based, holistic nursing approach. In this article, we describe the structure of group visits, the process of conducting Centering group visits focused on empowerment, and the content of a holistic curriculum for women with chronic pelvic pain.

Endometriosis: the role of neuroangiogenesis

Endometriosis is a common cause of pelvic pain and infertility, affecting ∼10% of reproductive-age women. Annual costs for medical and surgical care in the United States exceed $20 billion. The disorder is characterized by implants of endometrial tissue outside the uterine cavity. Endometriotic lesions induce a state of chronic peritoneal inflammation, accompanied by elevated prostaglandin, cytokine, and growth factor concentrations. The current therapy is surgical ablation of ectopic implants and hormones that block the hypothalamic-pituitary-ovarian axis, but these approaches are expensive, carry perioperative risks, or have unpleasant side effects of hypoestrogenism. Recent evidence indicates that ectopic endometriotic implants recruit their own unique neural and vascular supplies through neuroangiogenesis. It is believed that these nascent nerve fibers in endometriosis implants influence dorsal root neurons within the central nervous system, increasing pain perception in patients. We consider the mechanisms and therapeutic implications of neuroangiogenesis in these lesions and propose potential treatments for the control or elimination of endometriosis-associated pain.

Minimal endometriosis: a therapeutic dilemma?

Accidental finding of minimal endometriosis during surgery for complaints unassociated with endometriosis presents a therapeutical dilemma. Because the clinical significance of minimal endometriosis is not thoroughly defined, it is uncertain by which means, if at all, such types of peritoneal or ovarian lesions should be treated. We, therefore, compiled our clinical observations and evaluated them in relation to the results reported in the recent literature. A search on the clinical importance and the need for any treatment of minimal and mild endometriosis was conducted. Based on the available evidence, we are tempted to conclude that minimal endometriosis should be treated surgically when accidentally discovered. This approach should be exerted even in the absence of clinical symptoms. However, postoperative medical treatment is not warranted in those patients who are without clinical complaints. Because the clinical course of minimal endometriosis is not predictable, any benefit from specific medications remains uncertain. When associated with infertility, minimal endometriosis should be surgically erased, thus to allow spontaneous conceptions to occur. As there is no evidence of medical treatment modalities altering the clinical course of minimal and mild endometriosis, any specific medical treatment (i.e. GnRH analogues, danazol) is not indicated in asymptomatic patients and those desiring pregnancy.

Safety of the Helica Thermal Coagulator in treatment of early stage endometriosis

The objective of this prospective study was to assess the safety and short-term outcome of the Helica Thermal Coagulator in the laparoscopic treatment of early stage endometriosis. Two hundred and fifty consecutive women with chronic pelvic pain and stage I and II endometriosis (r-AFS classification) were treated laparoscopically with the Helica Thermal Coagulator. No bladder, ureteric or bowel injuries occurred. None of the procedures was converted to laparotomy and there were no major peri-operative complications. The only complication was a vaginal perforation during dissection of the cul-de-sac in a patient with a vaginal vault endometriotic nodule. We conclude that the Helica Thermal Coagulator is a safe alternative for the treatment of mild to moderate endometriosis. Long-term efficacy studies are required to better assess the role of the device in laparoscopic management of endometriosis.

A qualitative analysis of adolescents' experiences of active and sham Japanese-style acupuncture protocols administered in a clinical trial

INTRODUCTION

Acupuncture is a complex holistic intervention in which patient-practitioner relationships and healing changes occur in interactive, iterative ways. Qualitative research is one way to capture such complexity. This study sought to understand better the experiences of adolescents involved in acupuncture treatment.

MATERIALS AND METHODS

We included a qualitative substudy as part of a pilot randomized sham-controlled study of the use of Japanese acupuncture to treat chronic pelvic pain in adolescent girls. Seven (7) interviews were attained. Themes were double-coded and analyzed using qualitative analysis software.

RESULTS

Regardless of treatment arm, all subjects reported positive study-related changes, often attributed to positive qualities of the patient-practitioner relationship. Participants in both the sham and verum acupuncture treatment arms reported in the narratives that they were unsure of their study assignment. In contrast, the study's close-ended success of blinding question suggests that some participants were sure of their treatment allocation.

CONCLUSIONS

As we continue to study acupuncture using sham controls, we need a better understanding of the possible affects of sham treatments on both treatment outcomes and success of blinding. Qualitative research is one-way to explore subtle emergent changes in participants' experiences.

Over one thousand patients with early stage endometriosis treated with the Helica Thermal Coagulator (HELICA): safety aspects

STUDY OBJECTIVE

To assess the safety of the Helica Thermal Coagulator in the laparoscopic treatment of early stage endometriosis.

DESIGN

Retrospective, observational.

SETTINGS

The Princess Royal University Hospital, The Sloane and Chelsfield Park Hospitals, Kent, UK.

PATIENTS

One thousand and sixty patients with early stage endometriosis.

RESULTS

All patients were treated laparoscopically with the Helica Thermal Coagulator; a new laparoscopic device that combines electrical energy with helium for the treatment of endometriosis. No major bladder, ureteric or bowel injuries occurred. The only complication was a perforated vagina from the cutting probe during dissection of the cul-de-sac in a patient with a vaginal endometriotic nodule.

CONCLUSION

The Helica Thermal Coagulator is a safe device for the laparoscopic treatment of endometriosis.