Chronic pelvic pain (CPP) is a syndrome of complex origin that manifests as pain with a duration of more than 3 months and affects the anatomical pelvis. CPP affects a significant part of the population who are often at the most productive part of their life, and so it is no surprise that the socioeconomic burden is enormous. The causes are varied and can sometimes be multiple, but the most common causes vary with geographical location or study centre. Management of CPP requires a multidisciplinary approach involving the primary health care provider, secondary and tertiary specialist input and supportive medical ancillary services. It is important to note that, despite best efforts, management of CPP can be drawn out over a long period of time, improvement in painful symptoms may not always be significant and return to active and full productivity may never be attained. However, new methods of treatment and, in some instances, prevention of CPP are currently available to the medical armamentarium and the aim of this review is to update knowledge of available management options and, when possible, review evidence of their efficacy.
Internet databases were searched to identify literature on CPP. The keywords used were ‘chronic’, ‘pelvic’, ‘pain’, ‘management’, ‘update’, ‘management’, ‘endometriosis’ and ‘leiomyoma’ in various combinations in the Google and PubMed search engines, which yielded a total of 816 citations. Of these, 127 articles were most relevant and suitable for the review. Relevant articles in other languages were used as long as the abstract had been translated into English and some references from the articles were also reviewed. The majority of the articles that were used for the review covered some aspects of chronic pain and its management in the last 10–15 years.
Chronic pelvic pain has been defined as pain occurring below the umbilicus that lasts for at least 6 months and is severe enough to result in functional disability or require treatment.1 CPP has also been defined as a syndrome of complex origin manifesting as pain of more than 3 months’ duration that affects the anatomical pelvis.
Howard2 and Farquhar and Steiner3 have reported that CPP is the principal indication for approximately 20% of hysterectomies performed for benign disease and at least 40% of gynaecological laparoscopies.3,4
The reported prevalence of CPP ranges from 4% to 16%, but only approximately one-third of women with CPP syndrome seek medical attention.4–7 It has been reported that, in the USA, CPP syndrome accounts for about 10% of all ambulatory referrals to a gynaecologist and that it is a common indication for diagnostic and therapeutic surgery.8
The understanding of this condition and its management is a constantly evolving process with a multidisciplinary contribution9 and it involves the health care giver at the primary level to the tertiary subspecialist. CPP and its management can be drawn out over a long period of time, and the results of treatment can sometimes be disappointing.10 CPP is more common in women and those of child-bearing age (22–36 years), but it is known to occur in women aged 18–80 years. The economic cost of the condition has been estimated to about £154.8 million per year in the UK and an overall cost of $2 billion per year in the USA.11
Potential causes of CPP include gynaecological and non-gynaecological (urinary tract, gastrointestinal, musculoskeletal, mental health) causes, some of which are listed below.
Gastrointestinal tract causes
Musculoskeletal system causes
Mental health causes
It has been reported that, even though any one disorder may be the cause of CPP, pain can emanate from several medical conditions, with each contributing to the generation of pain and requiring management.1 For instance, a woman may be suffering from endometriosis, interstitial cystitis, emotional stress and pelvic floor pain related to muscular spasm.1
Women with more than one medical condition tend to have greater pain than women with only one disorder and, for some women, no diagnosis other than chronic pain can be established.12 This is often a source of frustration for both the patient and clinician.1
The starting point in the management of CPP is to consider all the causes of chronic pain in the pelvis13,14 and carry out a comprehensive history to evaluate these possible causes. A history of PID episodes, especially if confirmed by prior laparoscopy, will justify further evaluation for CPP. Sexual history is a cornerstone in evaluation of CPP in women as a significant number of women with CPP have suffered some form of abuse, whether sexual or another physical form.15,16 Socioenvironmental contributing factors should also be reviewed because evidence suggests that the outcome of treatment is best when this medical intervention is combined with treatment of any existing psychological morbidity and cognitive–behavioural pain therapy.17 The importance of a thorough history for the improvement of painful symptom cannot be overstressed as other risk factors associated with CPP could be elucidated from a detailed and effective history. Risk factors for CPP include other gynaecological causes such as peritoneal adhesions, pelvic congestion syndrome, endometriosis/adenomyosis and remnant ovarian syndrome. Endometriosis is a common gynaecological causative factor of CPP, accounting for 60% of cases (Figure 1).19 Urological causes include interstitial cystitis, pelvic kidney and urethral syndrome. Since 2001, following the approval for use of surgical mesh to treat pelvic organ prolapse, an emerging cause of CPP has been the use of these vaginal mesh implants.20 Gastrointestinal causes such as irritable bowel syndrome (IBS) and diverticular disease, and musculoskeletal/neurological causes, should also be reviewed. Other psychological associations with CPP include depression and somatization. Examination should reflect the multiple causes of CPP; thus, examination of the reproductive, gastrointestinal and urological systems will help in consolidating diagnosis made from the history.
Investigation of patients with CPP should be tailored to the historical and examination findings and the routine investigation carried out should include microbiology to rule out PID. Abdominopelvic ultrasonography with or without further imaging could be useful for diagnosing conditions such as endometriosis/adenomyosis and ovarian abnormalities as well as other causes of CPP. Computed tomography (CT) of the pelvis and abdomen would be useful in the localization and characterization of endometriosis, ovarian masses and varicose veins, and laparoscopic examination with or without tissue biopsy is also helpful in confirming a diagnosis. Other investigations that may be required, especially if there remains doubt about the diagnosis, include sigmoidoscopy, CT colonoscopy and magnetic resonance imaging (MRI) to confirm or rule out diagnoses of IBS or diverticular disease. In addition, urinalysis with cultures, if required, would help rule out urinary tract infections, and psychometric measurements, such as the Minnesota Multiphasic Personality Inventory, could be used to distinguish patients with non-organic pain from those with pain originating from pelvic pathology.17
The need for a multidisciplinary approach to the treatment of CPP cannot be overemphasized.21 Treatment may be directed to the cause of CPP or to general pain management, and it has been observed that the more effective methods involve a combination of both.22 Management options include oral and parenteral medications, surgery and varied approaches ranging from superior hypogastric sympathetic nerve block20,23 by the neuroanaesthesiologist to cognitive–stress behavioural therapy by a psychologist. Peripheral nerve field stimulation has been used in some cases of intractable pelvic pain with success recorded among a significant proportion of patients, who reported decreased analgesics requirement in the long term;24 however, a single-blind prospective study comparing differences in symptom improvement between patients treated with diagnostic laparoscopy with or without uterosacral nerve ablation did not show any difference of significance.25
Some of the most common gynaecological and non-gynaecological causes of CPP are outlined below.
Endometriosis results from the presence and proliferation of endometrial tissue outside the endometrium (Figure 2). Location varies from pelvic organs to distal sites outside the pelvis. The prevalence of endometriosis in women is approximately 6–10% and it affects mainly those of child-bearing age. Endometriosis can also present alongside dysmenorrhoea, dyspareunia, dysuria, infertility and CPP.
Endometriosis is the most common diagnosis made at the time of gynaecological laparoscopy for the evaluation of CPP,1 its prevalence ranging from 2% to 74%.27 It also presents a diagnostic challenge because of its various clinical manifestations depending on the pelvic anatomical location of the endometriotic deposit. Rectovaginal endometriosis represents the most severe form of endometriosis,28 although peritoneal and ovarian endometriosis tend to present more often. Laparoscopy with histological confirmation is the gold standard for diagnosis of CPP (Figure 3).
Other investigations, such as ultrasonography, MRI, CT, colonoscopy and contrast studies, can be employed to determine the extent of the condition. Treatment of endometriosis can be conservative medical, surgical or a combination. Medical treatment with the birth control pill, progestins and gonadotropin-releasing hormone (GRH) agonists produces varying outcomes in symptom improvement. Evaluation of these medical forms of treatment in one series seemed to show that the use of the cheaper and more readily available progestin preparations is as effective as, if not more effective than, the more expensive GRH agonists and can also be used for longer, but it should be noted that medical treatment is mostly cytostatic rather than cytoreductive.30,31 Other non-hormonal medications used in pain relief include non-steroidal anti-inflammatory drugs (NSAIDs) and opiates.32 However, surgical treatment can produce symptom improvement in up to 70% of cases.17 Surgical techniques include ablation, excision of endometriotic lesions via laparoscopy or open surgery for rectovaginal endometriosis, and a global success rate of 91% was demonstrated in one series, although complications arising from surgery need to be discussed thoroughly with patients pre-operatively.33
The use of a gluten-free diet as part of the treatment plan for CPP was evaluated by Marziali et al.,34 in a study involving 207 patients; at 12 months’ follow-up, 156 patients (75%) reported an improvement in painful symptoms.34 A diet rich in antioxidants has also being observed to be important in painful symptom relief in the management of CPP, but further studies, especially randomized trials, should be carried out to determine its effectiveness.35 It is noteworthy that comparisons of, surgical and non-surgical methods of treating CPP secondary to endometriosis have not shown one to be more effective than the other, and both have been found to relieve painful symptoms,36,37 which was the case in at least three different studies.36,37 However, Deguara et al.37 did find that the chance of achieving pregnancy was increased in patients who received surgical intervention compared with those treated medically.36,38,39 Hysterectomy as a form of treatment for CPP, although generally successful in controlling symptoms, can have disappointing results in terms of post-operative symptom relief and improved quality of life if there is no obvious pre-operative pathology. It is important to evaluate the likely cause of CPP to differentiate reproductive from other varied causes such as musculoskeletal, urological, neurological, etc., before undertaking a hysterectomy.40 CPP due to endometriosis that does not respond to other treatment can be managed using techniques such as anaesthetic infiltration or neurostimulation with or without surgery, and the effectiveness of this will be the subject of future randomized controlled studies.41 Additionally, the severity of CPP prior to first laparoscopy is a good predictive indicator of pain recurrence in patients with endometriosis treated surgically.42 A randomized, double-blind, placebo-controlled study indicated effectiveness in the use of N-palmitoylethanolamine-associated transpolydatin when compared with placebo-treated control subjects; however, a regular dose of the cyclooxygenase-2 (COX-2)-selective inhibitor resulted in better pain control than either placebo or N-palmitoylethanolamine-associated transpolydatin.43
Leiomyoma uteri (fibroid)
Leiomyoma uteri result from non-cancerous unregulated growth of the smooth muscle component of the uterus. The aetiology of fibroids is not known, but a genetic predisposition plays a strong role in its development. Fibroids can be multiple and are classified based on location, such as subserosal, intramural, submucosal and cervical. Fibroids may be asymptomatic for a long period of time, and their presence may be an incidental finding, but, when they are symptomatic, the symptoms include a dragging sensation, abnormal bleeding, CPP and, in some cases, infertility. Investigation to confirm diagnosis is usually via ultrasonography, or MRI can be employed to delineate fibroid masses within the uterus.
Chronic pelvic pain caused by the presence of leiomyomata (Figure 4) can be treated by conservative, medical, radiological and surgical means, depending on the severity of pathology and the patient’s need to preserve fertility and her general state of health. Asymptomatic fibroids are usually treated with watchful expectation and some medical agents have been used to treat symptomatic fibroids. A review by Sabry and Al-Hendy45 evaluated the use of oral agents such as vitamin D, selective oestrogen receptor modulators, anti-progestins, aromatase inhibitors and somatostatins analogues to treat leiomyoma. The effectiveness of these agents is varied and further randomized clinical trials are required to determine their safety.
Uterine artery embolization or ligation treatment acts by disrupting the blood supply to the fibroid, thereby decreasing the growth rate or stopping growth and encouraging shrinking of the fibroid mass.
Radiofrequency ablation is one of the newest treatment options available and utilizes radio waves to shrink fibroid tumours; however, further studies are needed to evaluate efficacy and long-term safety. The surgical treatment for fibroid is myomectomy, which can be carried out through laparoscopy, hysteroscopy and open laparotomy, and it remains the treatment of choice when conservative measures fail, when the patient is desirous of achieving pregnancy and when the patient wants to retain the uterus. However, it must be stressed to the patient that myomectomy surgeries can be complicated by the need for hysterectomy as leiomyoma uteri are the leading cause of hysterectomies.
Magnetic resonance-guided focus ultrasonography is a non-invasive treatment option for uterine fibroids and is more cost-effective and results in more quality-adjusted life-years than the older, traditional surgical treatment options such as myomectomy. Further studies are currently under way to determine effectiveness compared with other surgical treatment options.46,47
Pelvic inflammatory disease
Pelvic inflammatory disease is an ascending infection involving the uterus and fallopian tubes and may or may not involve the ovaries.
Causative organisms in PID have traditionally included Neisseria and Chlamydia spp., but endogenous organisms such as vaginal and cervical flora have also been implicated. Presentation can be subclinical, although serious damage may have been done even at this stage, and signs and symptoms include vaginal discharge, acute abdominopelvic pain and infertility. Ness et al.48 reported that as many as 30% of women with PID subsequently develop CPP. In view of this, PID is a common cause of CPP in settings with a high prevalence of sexually transmitted disease. A study investigating the development of CPP following an acute episode of PID seems to demonstrate that the severity of adhesive and tubal disease and the persistence of pelvic tenderness 30 days following the treatment of acute PID are two important factors.49 The exact means by which PID progresses to CPP is poorly understood, but factors increasing the likelihood of PID progressing to CPP include a history of smoking, more than one episode of PID and a low composite mental health score on a standardized test.50 CPP can be a manifestation of PID, and diagnosis usually involves microbial culture; ultrasonography and laparoscopy will usually show evidence of an established disease or its aftermath. Appropriate antimicrobial therapy is usually commenced even before definite microbiology culture confirmation, and the effectiveness of such treatment tends to be inversely correlated with the duration of disease.51 Antibiotic therapy should preferably be broad spectrum, although shorter courses of monotherapeutic agents are becoming quite popular.52 Preventative measures are important in the management of PID and such measures include use of barrier methods to reduce the spread of STIs, and early presentation, diagnosis and treatment of infection.53
Irritable bowel syndrome
Irritable bowel syndrome is a diagnosis of exclusion once organic causes for the symptoms of chronic abdominopelvic pain, bloating, constipation and diarrhoea have been ruled out. IBS can be a diarrhoea- or constipation-dominated variant. The cause of IBS is unknown, but current thinking suggests that there it may be in part caused by gut infection,54 brain–gut derailment55 and psychological influence.56 Investigations are generally required to rule out other causes of symptoms, and these would vary with the predominating symptom type.
Irritable bowel syndrome-related CPP is the most common cause of abdominopelvic pain in the general population57 and it may coexist with other causes of chronic pain such as inflammatory bowel disease,58 fibromyalgia and headache,59 and endometriosis.60 There is currently no cure for IBS, but management of symptoms can be achieved with dietary modification and increased use of soluble fibre in meals. This provided symptom relief in as many as 60–80% of patients in one study.61 Treatment with the 5-hydroxytryptamine agonist tegaserod (Zelnorm® and Zelmac®, Novartis) has proved effective in controlling constipation-related IBS; however, caution should be taken owing to its adverse cardiovascular side-effects. Loperamide and alosetron (Lotronex®, GSK), a 5-HT3 antagonist, are effective in controlling diarrhoea-related IBS.62 Psychotherapy has been used in treatment of IBS, and cognitive–behavioural therapy has been found to produce symptom relief in some stuies.63,64 Alternative therapies, such as yoga, acupuncture and herbal remedies, have been tried by up to 50% of patients and different levels of symptoms relief have been achieved.65
Diverticular disease is outpocketing of the colonic mucosa and submucosa as a result of weaknesses in the muscular layer of the colon, and inflammation of these outpockets results in diverticulitis. The cause of diverticular disease is not fully understood, but increased intraluminal colonic pressure and a fibre-deficient diet are posited to be contributory. It most commonly affects the sigmoid colon, and the role of dietary fibre in the pathophysiology and treatment of diverticulosis has been questioned in a recent study,66 which seems to suggest that high dietary fibre may not be as beneficial in symptom relief of diverticular disease as previously thought.
Other risk factors associated with the development of diverticular disease are increasing age, connective tissue disease, constipation and hereditary factors. Signs and symptoms, when present, include left lower quadrant abdominal pain, bloating, abdominal cramp, diarrhoea, constipation and per rectal bleeding. In more complicated cases, signs and symptoms include abdominal distension, colonic perforation and abscess formation.
The diagnostic option of choice is CT with contrast (Figure 5), although colonoscopy is useful for ruling out malignancy. Treatment of uncomplicated diverticular disease involves the implementation of a high-fibre diet, but complicated diverticular disease, such as diverticulitis, can be treated conservatively with bowel rest, with or without antibiotics, and pain relief with opiates is also beneficial. Other complications, such as perforation and abscess formation may be amenable to surgery on an emergency or elective basis.
Interstitial cystitis is a chronic non-infective inflammation of the bladder, associated with painful and irritative bladder voiding; hence it is also known as painful bladder syndrome. Features of the pathology were known and described as far back as 1836.68 It predominantly affects women and is rare in children – the average age at onset is 40 years.69 The pathophysiology is poorly understood, and there are different theories of the cause, but the basic factor seems to include increased permeability of bladder epithelium to urinary potassium,70 which also forms the basis of one of the tests used in making a diagnosis of interstitial cystitis (Parsons’ test), in which the symptoms can be reproduced by instillation of potassium chloride solution into the urinary bladder. However, this test is falling out of favour owing to its low sensitivity and specificity and it is also an invasive procedure that can cause pain. The American Urological Association recommends taking a proper history and carrying out a detailed physical examination and appropriate investigations to aid in the diagnosis of interstitial cystitis. Cystoscopy with hydrodistension and biopsy can aid in the diagnosis of interstitial cystitis and, in practice, diagnosis is empirical following the exclusion of other causes of similar symptoms and treatment can then be initiated. Other diagnostic measures include the detection of urinary markers, antiproliferative factors (most sensitive and specific)71 and phenylacetylglutamine.72 Interstitial cystitis has been found to be associated with endometriosis73 and commonly presents with other causes of CPP.74 The treatment guideline by The American Urological Association advises a graded treatment of interstitial cystitis: first-line management modalities comprise patient education, lifestyle and dietary modification and stress management; second-line treatment options include physical therapy and medications, including use of analgesics and antihistamines; third-line treatment options include treatment of Hunner’s ulcer and hydrodistension; the fourth-line treatment option is neuromodulation; the fifth-line treatment option is use of cytotoxic and botulinum toxin; and the last treatment line is surgical to include urinary diversion or cystectomy. Other treatment options, such as instillation of bacille Calmette–Guérin and prolonged use of antibiotics and steroids, have been abandoned.73 It has been stressed that, despite all these measures that can be employed, no known curative measures exist.75
Pelvic floor myalgia
Pelvic floor myalgia as a cause of CPP is treatable using an individualized physiotherapy regimen.73 Refractory cases have been found to be amenable to courses of botulinum toxin injections,76–79 although further randomized controlled studies are needed to determine the efficacy of their use.
Pelvic adhesions that mainly arise from previous lower abdominal surgery or previous episodes of PID contribute to development of pelvic adhesions, irrespective of cause. Pelvic adhesions may also lead to CPP, and treatment often involves employing the necessary surgical technique to prevent/reduce adhesions; however, if they do occur, adhesiolysis can be used as a treatment option, but it is important to discuss the complications of this surgery with the patient preoperatively as the operation is associated with the risk of creating further adhesions.80
Management of some specific, but less common, causes of CPP is described below.
Chronic pelvic pain after irradiation therapy for pelvic malignancy, for example cervical cancer, negatively affects rehabilitation and quality of life.81 Management modalities currently include multidisciplinary approaches such as analgesics and psychological and physical therapy.
Management of CPP that follows the use of mesh to treat pelvic organ prolapse, which can be affect as many as 30% of patients who have had reconstructive surgery using mesh, has been hampered by lack of robust data.82 Currently, treatment options for these include partial or complete mesh release and complete removal of mesh in patients whose primary cause of chronic pain was the presence of the mesh.83
Chronic granulomatous conditions such as actinomycosis (Figure 6) may contribute to CPP. The development of this chronic infective process has been associated with prolonged use of intrauterine devices83 and treatment involves a prolonged course of antibiotics,85 with or without surgical debulking.
Abdominal myofascial pain syndrome
Abdominal myofascial pain syndrome (AMPS) is the presence of localized abdominal muscle pain that affects one side of the abdomen more than the other. Features suggestive of AMPS include a history of recent abdominal surgery, pain relieved by contraction of abdominal muscle, a history of repetitive abdominal stress and obesity. The diagnosis of AMPS as a cause of CPP is complicated by the fact that some other causes of CPP may coexist with AMPS. Pain in AMPS originates from muscle trigger points and the trigger points can be determined during the detailed examination of patients suspected of having AMPS; investigations are also carried out to exclude other causes of pain. First-line treatment options include NSAIDs or COX-2 inhibitors with alternating cold and heat compression. Other lines of treatment include the use of local anaesthetic patches or injections over or into the muscle trigger points.
Persistent pelvic pain after childbirth
Persistent pelvic pain following childbirth may result from pelvic ring instability and, although this is uncommon, management options are mainly conservative. A study showed no significant difference in outcomes in surgically treated patients and those managed conservatively.86
Chronic pelvic pain of unknown origin
Cases of CPP in which the origin of pathology is not obvious can benefit from somatocognitive therapy.87,88 A study88 in which 40 subjects with CPP and unexplained pelvic pathology were randomly assigned to two groups treated with either gynaecological intervention alone and gynaecological intervention with somatocognitive therapy demonstrated a significant difference in outcomes in both the immediate post-treatment period and at a 1-year follow-up. The possibility of drug-seeking behaviour should be borne in mind when managing CPP with oral and parenteral medications; Fenton et al.89 demonstrated that 13% of their study group exhibited drug-seeking behaviour.
Irrespective of the cause, CPP has been shown to adversely and significantly affect quality of life.90 It is more likely that the symptoms will be managed than cured91 and it is generally accepted that the first point of contact, who is usually the general practitioner, could play a greater role in the initial diagnosis and management of CPP.92,93 The initial consultation for CPP has been determined to play a significant role in the overall satisfaction of patients at subsequent follow-ups, and general practitioners need to provide appropriate information and set expectations in addition to giving emotional support during the consultation.94 The primary physician should be willing to spend time with the patient and coordinate referrals to specialists to improve the outcome of symptoms in patients with CPP.95
Chronic pelvic pain can be a debilitating condition that adversely affects the quality of life of women affected and the burden of this disease is enormous. Management starts from the initial consultations, and the most common causes, such as endometriosis, IBS, PID and interstitial cystitis, can be treated with significant improvement in symptoms; other causes may not respond favourably to treatment and managing CPP can be long and drawn out; thus, treatment should commence from the simplest form to the more complex.96 The primary physician has a significant role to play, and the efficacy of some treatment modalities would be established after further randomized controlled studies are carried out. The psychological management of CPP is highly significant, especially in cases for which no obvious organic pathology can be found. Further randomized controlled trials are required to evaluate the efficacy of some of the management options currently available to treat CPP and additional research is also required to enlighten us about the pathology of, and subsequently better treatment approaches for, some of the causes of, CPP.