A Scoping Review on Interventions for Chronic Pelvic Pain

Chronic pelvic pain (CPP) is defined as recurrent or constant pelvic pain of at least 6 months duration, unrelated to periods, intercourse, or pregnancy. The prevalence of chronic pain is 24%. One-third of the women had pain for more than 5 years. Patients suffering from CPP refrain from seeking medical help and they usually neglect it terming it as dysmenorrhea. Patients with CPP have a coexisting anxiety disorder (31%) as compared with women with dysmenorrhea (7%).[] There is a wide range of possible causes for CPP, most of which are difficult to diagnose and treat. The main gynecological diagnoses – which are mostly confirmed during laparoscopy – include endometriosis, chronic pelvic inflammatory disease, and adhesions.[] Given the longer course the CPP takes to manifest, it is often missed in the initial stages. There is no specific test for diagnosis of CPP. However, tests can be advised if co-existing gynecological conditions are suspected. ETIOLOGY CPP is usually found in association with irritable bowel syndrome, and interstitial cystitis. Apart from organic causes, the prevalence of CPP is high in patients with anxiety disorder, mood disorder, depression, and posttraumatic stress disorder.[] It is also seen that patients with CPP have a higher incidence of depression, anxiety, and sleep disorders. This leads to a vicious cycle of pain leading to mood and affective disorder and this in turn leads to pain. Mental trauma, physical abuse, and childhood sexual abuse can lead to posttraumatic stress which may be overseen and can lead to CPP.[] Other organic causes linked with the causation of CPP include nerve root entrapment, sacral cysts, leiomyomas, and cauda equina syndrome.[] The equivalent in males, chronic prostatitis/CPP syndrome (CP/CPPS) is characterized by persistent pain and discomfort in the pelvic region and poses a management challenge due to its multifactorial nature. Accurate diagnosis involves subtyping based on symptoms, distinguishing between inflammatory, noninflammatory, pelvic floor dysfunction, and asymptomatic inflammatory prostatitis. Treatment strategies encompass various approaches, including pharmacotherapy with nonsteroidal anti-inflammatory drugs (NSAIDs), alpha-blockers, physical therapy, stress management, and extracorporeal shockwave. The conclusions of the past 5 years of systematic review and meta-analyses are listed in Table 1. MECHANISM OF DEVELOPING CHRONIC PELVIC PAIN Impairment in the central pain processing pathway has been attributed to the development of CPP. The body’s threshold for pain is reduced, so even mild pain is experienced as severe pain (hyperalgesia). In addition to these normal sensations such as touch can be misinterpreted as pain (allodynia). The central sensitization sets in which involves the following mechanism: Central reorganization: Following nerve injury Aa fibers form convergence in lamina II and synapse with the neurons conveying nociception resulting in mechanical allodynia, area of pain increases along the distribution of other nerves due to activation of interneurons at the spinal level, loss of function of descending inhibitory pathways Disinhibition: Downregulation of inhibitory neurotransmitter GABA, glycine, and opioid receptors in the dorsal horn of the spinal cord Ectopic discharges: Facilitation of the excitatory synapses Wind-up phenomenon: Repeated stimulation of C fibers results in the temporal summation of inputs from them increasing the excitatory stimulus Activation of Wide Dynamic Range (WDR) neurons. WDR cells are recruited in the pain pathway. The above mechanisms lead to central sensitization which results in: Increase in the intensity, area, and duration of pain Decrease in the tolerability of pain Development of psychological problems Pain becomes unresponsive to conventional analgesics.[] EVALUATION OF THE PATIENT WITH CHRONIC PELVIC PAIN Since the association of CPP and central pain mechanisms has been established, it is important to obtain a history regarding central sensitization such as features of hyperalgesia and allodynia. A history regarding previous gynecological/obstetric intervention may help narrow down the diagnosis. Symptoms associated with CPP such as menstrual disturbances, urinary symptoms, sexual, and psychological should also be evaluated. Patients may also have autonomic or motor dysfunction which needs to be evaluated.[] Apart from evaluating in lines of CPP, care should be given to assessing red flag signs to rule out malignancy. A history of weight loss, pelvic mass, hematuria, postcoital bleeding, and postmenstrual bleeding should trigger suspicion and further assessment to be done to rule out malignant causes. Apart from history, gynecological examination and full pelvic and abdominal examination needs to be carried out. Other neuraxial pain such as myofascial pain, facet arthropathy, sacroiliac joint arthropathy, and lumbosacral transitional vertebra should be evaluated for and ruled out. A workup plan is illustrated in Figure 1 for evaluating a patient with CPP. Once history and examination are done and other obvious causes ruled out, the patient may be asked to get blood and radiological workup to be done. A baseline laboratory investigation such as complete blood count, erythrocyte sedimentation rate/C-reactive protein, liver function test/renal function test may be needed, in addition to specific organ function test, if their derangement is suspected. Acute onset severe pain goes against the diagnosis of CPP and needs prompt evaluation by the emergency department. Diagnostic blocks can be done to rule out the neuraxial causes, for example, diagnostic facet block if facet joint arthropathy is suspected, and selective nerve root block if nerve entrapment is suspected. MANAGEMENT Patient education regarding the mechanism of development of CPP can help decrease the anxiety and apprehension associated with the disease and help improve patient compliance with the treatment. The mainstay of treatment is to identify the causative factor that led to CPP and treat it and prevent further complications. If no causative factor is found, then the first line of medications includes paracetamol and NSAIDs.[] If a neuropathic component is seen, then the addition of an antiepileptic (pregabalin/gabapentin) or anti-depressant (nortriptyline, sertraline, and duloxetine) will be beneficial. The combination of the above has been more beneficial than when used alone.[] Hormonal replacement therapy has been found helpful in postmenopausal patients suffering from CPP with no other etiologies. The role is opioid analgesics in chronic pain conditions is questionable. If CPP is associated with other causes, then a trial of opioids as a part of multimodal analgesia can be tried out. Another nonpharmacological treatment has been tried for CPP. Pelvic floor exercises improve pelvic muscle tone and may alleviate pain. Cognitive behavioral therapy is beneficial. It decreases stress and enhances productivity.[] Once a specific diagnostic block is successful in relieving pain, then radiofrequency ablation can be planned. Cutaneous injections at trigger points with local anesthetic have been tried. If the patient gets relieved by these trigger point injections, a diagnosis of myofascial pain syndrome can be made. Neuromodulation with spinal cord stimulation or transcutaneous electrical nerve stimulation has also shown positive results.[] Numerous measures have been tried with variable success to mitigate the symptoms of pain in patients of CPP. Considerable overlap of etiologies exists in patients experiencing the symptoms and a patient-specific comprehensive approach can help alleviate pain. A summary of observations noted from systematic review and meta-analysis conducted in the past 5 years (2018–2023), listed on PubMed is tabulated in Table 1. The table has three sections-interventions, pharmacotherapies, and alternative therapies. The table demonstrates a variety of clinical entities and syndromes, including CP/ CPPSs, myofascial pelvic floor pain, pelvic venous reflux, and chronic pain due to other causes, contributing to CPP. Certain intervention modalities such as the extracorporeal shockwave for CP/CPPS in males have been listed separately under intervention as shown in Table 1.

CPP involves complex central and peripheral mechanisms in its development. Prompt identification of the causative factor of CPP helps in targeted management. The management involves multiple pharmacological and nonpharmacological approaches. The treatment should aim at improving the symptoms and providing a better quality of life for the patient. Treatment of CPP needs a multidisciplinary approach and robust communication should be built by all the treating doctors for the best outcomes. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

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