Chronic pelvic pain in Australia and New Zealand

With so little research into chronic pelvic pain (CPP) worldwide, current management occurs in a vacuum of knowledge few areas of medicine would accept. No statistical data for the prevalence of CPP in Australia are available, but if CPP is defined as pelvic pain on most days for more than six months, then estimates of community prevalence range from 15% (USA)1 to 25.4% (New Zealand).2 This compares with Australian Bureau of Statistics prevalence data of 10% for asthma3 and 14% for back pain.4 Economically, pelvic pain is estimated to cost Australia more than $6 billion annually in direct costs.5 Simoens estimates the reduced quality of life in women with endometriosis-associated symptoms treated in referral centres at 0.809 quality-adjusted life years.6 Despite this, Australia's National Women's Health Policy7 mentions pelvic pain only in the context of chlamydial pelvic infection, and unlike asthma and musculoskeletal conditions, pelvic pain is not considered a National Health Priority Area. The complexity of the condition may be a contributing factor. While medical professionals divide the pelvis into gynaecological, gastroenterological, urological, musculoskeletal, neurological and psychological systems, the ‘cross-talk’ between organs and the presence of the medical condition ‘chronic pain’ makes these distinctions unhelpful. A woman's pain experience may include any or all of dysmenorrhoea, bladder dysfunction, irritable bowel, pelvic muscle spasm, vulvodynia, migraine headaches, fatigue, anxiety, low mood, poor sleep, premenstrual symptoms, pudendal or other peripheral neuralgias and postsurgical pain. The lack of prior research and rapidly expanding knowledge of chronic pain mechanisms provide extensive research opportunities. Australian and New Zealand researchers have made landmark progress identifying nerve fibres in both eutopic endometrium and endometriotic tissue (University of Sydney),8 localising candidate endometriotic gene loci (Queensland Institute Medical Research),9 determining the role of angiogenesis in endometriosis (Monash University),10 investigating potential blood diagnosis of endometriosis through microRNA profiling (University of Adelaide), the role of Toll-like receptors and oestrogen in female nociceptive pain (University of Adelaide)11 and identifying immune factors relevant to endometriosis (University of Sydney).12 While many of the principles of neuroscience developed for other pain conditions can be adapted to pelvic pain, current research is almost exclusively performed in either male humans or male rodents. The effects of the hormonal environment on inflammatory mediators, cytokines and nerve fibre density13 are now recognised, and the need for gender-specific pain research is evident.14 Male-to-female transsexual patients treated with oestrogen supplementation and testosterone suppression report an increase in chronic pain conditions.15 Future areas of interest include the effect of environmental pollutant exposure at sensitive (including neonatal) developmental stages, the potential for an endometriosis vaccine and the effect of the immune system on the systemic features of pain. Important Australian and New Zealand research includes the benefits of botulinum toxin and pelvic physiotherapy for pelvic muscle spasm or pudendal neuralgia,16, 17 accurate statistical information on the incidence of severe dysmenorrhoea symptoms in Canberra teenagers,18 the narrative descriptors women use when describing pelvic pain,19 dietary management of gastrointestinal symptoms,20 the recognition that bladder pain syndrome is frequently present in women with CPP,21 and that bowel symptoms while a frequent comorbidity in women with endometriosis are usually present without bowel lesions.22 Future areas for research include accurate statistical data for CPP, techniques to minimise de novo central sensitisation following surgery, inclusion of comorbidities in treatment evaluation, the role of diet in inflammation and symptom management, optimal pelvic physiotherapy techniques in women with pelvic muscle spasm and dyspareunia, refinement of the clinical situations in which surgical intervention is appropriate, optimal dosage regimes for neuropathic medications in our patient population, improved management of postoperative pain where narcotics are ineffective, and importantly, investigation of the factors that influence the transition from severe dysmenorrhoea to CPP. The neuroscience of chronic pain describes peripheral drivers of pain that may be the initiating factor, central sensitisation of nerve pathways and the brain adaptation to chronic pain. In this context, an approach to care that promotes improved function and well-being rather than cure may be the most appropriate. Gillett and Jones23 have authored a practical assessment and management paper on the role of the nervous system in pelvic pain. Jarrell et al.24 describe CPP management guidelines from the Canadian CPP Working Group. From a patient perspective, women look to gynaecologists for pelvic pain care. Meeting their expectations requires knowledge of the presenting symptoms of painful conditions outside traditional gynaecological organs, and the development of a network of colleagues able to assist in the management of her individual concerns. Such colleagues are likely to include a pelvic physiotherapist able to teach pelvic muscle relaxation, dietician experienced in food intolerance, psychologist with chronic pain experience, pain medicine specialist, vulvar dermatologist, psychiatrist and gastroenterologist experienced in the management of functional bowel symptoms. While good surgical skills where needed should be considered essential, a good surgeon also knows when not to operate, especially where re-operation is considered. CPP may be one of the few areas of chronic pain where prevention is possible. Teens with severe dysmenorrhoea unresponsive to the oral contraceptive or anti-inflammatory medications appear to be a group at higher risk of CPP. Effective management has the (unproven) potential to alter outcomes. Effective care provides an opportunity to avoid the increasing problem of prescription opioid dependence in women with undiagnosed pain. Darnell comprehensively outlines the gender-specific risks and consequences of long-term opioid therapy in women.25 October 2012 marked the start of the Global Year Against Visceral Pain, with CPP recognised by the Faculty of Pain Medicine as a priority area of need. The opportunity to undergo training and achieve dual fellowships with the Faculty of Pain Medicine already exists for registrars in general surgery, neurosurgery, medicine, psychiatry, anaesthesia, rehabilitation and general practice. 2013 marks the first advanced FRANZCOG training position in gynaecology and pain medicine through the Royal Hospital for Women in Sydney and the Women's Health and Research Institute of Australia (WHRIA) with the hope that similar opportunities may be available for FRANZCOG trainees. In 2013, the first ‘Pain Management for Surgical Trainees’ course will be held at Neuroscience Research Australia, Sydney. The course will include teaching on pain management in both the acute postsurgical and chronic setting for trainees from any surgical specialty. Gynaecologists are well placed to care for women with pelvic pain, especially where the opportunity to update skills is available. With such a large population group affected, improving care will require the majority of gynaecologists to take this opportunity. The article ‘Persistent Pelvic Pain in Women: Rising to the Challenge’ featured in this journal is both timely and commended to all Fellows and Diplomates of the college.26