Advances in the Treatment of Chronic Pelvic Pain: A Multidisciplinary Approach to Treatment

Abstract

The treatment of chronic pelvic pain can often be difficult, as many times after visits to multiple providers, patients can carry multiple diagnoses. Even with appropriate treatments, patients often have continued pain that can result in frustrations for both patients and their providers. Utilizing a multidisciplinary and multimodal approach to chronic pelvic pain is beneficial, especially when including evaluation for musculoskeletal dysfunction or other contributors to chronic pelvic pain.

Introduction

Pelvic pain is often a difficult condition to treat. Even when a diagnosis is found, treatment of the cause often doesn’t elicit the expected results. This can be due to the fact that the pain can have multiple presentations and often carries a multifactorial etiology. Due to the multitude of contributing factors, a multidisciplinary approach to treatment of patients with chronic pelvic pain (CPP) is often optimal for their care.

Chronic pelvic pain is defined as pain in the region of the pelvis for greater than six months. It may involve the visceral or somatic system and encompassed structures supplied by the nervous system from the tenth thoracic spinal level and below.^{1, 2} More specifically, this pain can be located between the umbilicus and the thighs. Chronic pelvic pain carries a broad differential diagnosis, including the gynecologic, urologic, gastrointestinal, neurologic, and musculoskeletal systems. It is important to remember that patients may have multiple conditions that lead to CPP. The challenge in treating patients with CPP lies in identifying the pain generator and effectively treating the identified conditions.

One of the musculoskeletal causes of CPP can be levator muscle spasm or pelvic floor dysfunction. Literature suggests that the pelvic floor muscles contribute to CPP in women as both the primary pain generator and as a compensatory contributor.^{3, 4} Pelvic floor dysfunction (PFD) may occur as a result of inherent musculoskeletal causes in the pelvic floor muscles, ligaments and tendons or PFD may occur as a functional adaptation to other disorders within the pelvis-hip-spine complex. It is common to see pelvic floor dysfunction arise in patients with visceral pelvic diseases, such as endometriosis or irritable bowel syndrome. Therefore, part of the reason chronic pelvic pain is so difficult to treat is because the pelvic floor muscles are often involved as a pain generator, so without treating these muscles as well as the initial disease, the pain may continue.

Studies have examined the role of the pelvic floor muscles in patients with interstitial cystitis/painful bladder syndrome (IC/BPS) and have found that myofascial pain and pelvic floor dysfunction are present in as many as 85% of patients with the diagnosis of IC/BPS.⁵ Bassaly et al⁶ evaluated patients with co-existing myofascial pelvic pain and IC/BPS and reported that over 78% of patients with IC/PBS were found to have at least one myofascial trigger point on pelvic exam. Additionally, 67% of patients had six or more trigger points.

Anatomy of the Musculoskeletal Pelvis

The pelvis is composed of a bony ring, which serves as a site for multiple cartilaginous, ligamentous and tendon attachments.⁷ The female pelvis is smaller, shallower and wider than the male pelvis, and this can lead to an increase in injuries that can occur in the female pelvis. The sacroiliac joints are located in the posterior pelvis while the pubic symphysis is located anteriorly; these joints are stabilized by ligaments. Extending from the sacrum is the coccyx that acts as an important ligamentous and tendinous anchor.

The pelvic floor is composed of muscles, ligaments, and fascia that act as a sling to support the bladder, reproductive organs, and rectum. The pelvic floor muscles (PFM) are divided into three layers: the superficial perineal layer, the deep urogenital diaphragm layer, and the pelvic diaphragm. The superficial PFM are the bulbospongiosus, ischiocavernosus, and superficial transverse perineal muscles. The deep PFM that line the inner walls of the pelvis are the levator ani and coccygeus that along with the endopelvic fascia comprise the pelvic diaphragm. The levator ani is a muscle group composed of three muscles - the puborectalis, pubococcygeus, and iliococcygeus. Lining the lateral walls of the pelvis are the piriformis muscles and obturator internus.

The PFM receive innervation through somatic, visceral, and central pathways. The skin of the lower trunk, perineum and proximal thigh is innervated by the iliohypogastric, ilioinguinal, and genitofemoral nerves via the lumbar plexus. There are three main terminal branches of the pudendal nerve, including the inferior rectal nerve, the perineal nerve, and the dorsal nerve of the penis/clitoris. The pudendal nerve innervates the penis/clitoris, the bulbospongiosus and ischiocavernosus muscles, the anterior portions of the levator ani muscles, the perineum, the anus, the external anal sphincter, and the urethral sphincter. This nerve contributes to many important functions, including external genital sensation, continence, orgasm, and ejaculation. Muscles of the levator ani are thought to have direct innervation from sacral nerve roots S3–5.⁸

History and Physical Exam

The history and physical exam are important tools in evaluating a person with CPP. Patients should be questioned about their pain – onset, mechanism of onset, location, quality, intensity, frequency, aggravating and relieving factors, quality, and radiation of pain. It is important to understand any previous treatments they have undergone to manage their pain. This may include medications, physical therapy, interventional procedures or surgeries. A thorough review of systems involving the pelvic organs is important in the evaluation of pelvic pain. Table 1 illustrates important questions regarding various organ systems that may be involved in the patient’s pain complaints. A bladder diary may be beneficial in evaluating the patient’s urinary habits and fluid intake. Another extremely important aspect of the history includes questioning the patient about any history of abuse, including physical, emotional, verbal or sexual abuse.

Table 1.

Important aspects of the history for patients with chronic pelvic pain

Bladder How many times per day do you typically urinate or how often do you urinate (frequency)? When you have to urinate, do you feel like you have to get to the toilet immediately (urgency)? What do you drink throughout the day (specifically, how much and what beverages)? What do you drink after dinner? Do you feel like you are emptying your bladder completely? Do you have difficulty starting the flow of urine? Do you have pain with urination? Do you ever experience urinary incontinence or leaking? ○ With coughing and sneezing? With standing from a chair? With exercise? ○ Do you ever have difficulty making it to the toilet in time? ○ Do you have incontinence during intercourse? ○ Are you ever incontinent at night while sleeping? ○ How often are you incontinent? ○ Do you wear a pad? If yes, how often do you change the pad? How many times do you get up at night to urinate? Do you have frequent urinary tract infections? Bowel Are you constipated? How often do you have a bowel movement (BM)? Have you ever been diagnosed with irritable bowel syndrome (IBS)? Do you have to strain to empty? Do you ever have to push from your vagina in order to have a BM? Do you feel like you have to continue to wipe more than normal in order to get yourself clean? Are your stools hard or soft? Do you have pain during or after a BM? Gynecologic Are your periods regular? Do you have severe menstrual cramps? Did you have menstrual cramps during adolescence? What if any treatment did you have for that? Do you wear tampons? Is it painful to wear tampons? Are gynecologic exams painful for you? Have you ever been diagnosed with endometriosis? If yes, how was this diagnosis made? Do you have problems with chronic yeast infections? Are you sexually active? Do you have pain with intercourse? ○ With coughing and sneezing? With standing from a chair? With exercise? ○ When it is painful (initial penetration, deeper penetration)? ○ Do you have pain after intercourse? If so, how long does this last? ○ Is it painful when you orgasm? Obstetric How many times have you been pregnant? How many children have you had? What was the largest birth weight? Did you have significant back or pelvic pain during pregnancy? How long were you in labor? How long did you push? Did you have tearing or an episiotomy? Did the delivery require use of vacuum or forceps? Any complications during labor and delivery? Psychiatric Do you have a history of depression or anxiety? Have you ever been hospitalized for psychiatric illness? Have you ever had thoughts of killing yourself? Have you ever been the victim of abuse (physical, sexual, emotional, verbal)? Are you currently in an abusive relationship/situation?

The physical exam should be guided by the patient’s complaints but should typically include a neurologic and musculoskeletal exam focusing on the lumbar spine, hips, pelvic girdle, lower extremities and pelvic floor muscles. An abdominal exam is also crucial in evaluating causes of pelvic pain, including scar tissue from previous procedures, which can play a major role in the development of pelvic pain.

Multidisciplinary Treatment of Pelvic Pain

When determining treatment plans for pelvic pain, the ability to determine the etiology will help to guide management. However, for many cases the etiology will remain unknown or multifactorial. General treatment for chronic pelvic pain, as recommended by a Cochrane review, includes: hormonal treatments, counseling after negative ultrasound, multidisciplinary approach to pain management, physical therapy, psychotherapy, diet and environmental factors.⁹ Often successful treatment requires a multimodal and multidisciplinary approach involving physiatrists, pain physicians, obstetricians-gynecologists, urologists, gastroenterologists, primary care providers, physical therapists, psychiatrists and psychologists. There have been several studies performed that have shown benefit to treatment of chronic pelvic pain with a multidisciplinary approach.^{5, 10} While most of these studies focus on the treatment of interstitial cystitis/painful bladder syndrome, this same multidisciplinary approach can be applied to the treatment of chronic pelvic pain in general.

Given the strong contribution of the pelvic floor muscles, inclusion of a physiatrist in the multidisciplinary team is crucial. Physiatrists are uniquely qualified and trained to manage pelvic floor pain for several reasons.⁷ Physiatrists have experience in managing functional and neurological bladder and bowel dysfunction. Physiatrists also have expertise in managing musculoskeletal disorders, including disorders of the hip, bony pelvis, or spine condition that may be contributing to the chronic pelvic pain. Finally, physiatrists offer intervention outside the realm of surgery, where the focus of treatment is to reduce pain and improve function.⁷

Pharmacology

Generally, pharmacologic treatment in chronic pelvic pain is used to treat pain and secondary etiology such as depression, anxiety, and insomnia. Nonsteroidal anti-inflammatories may be used for acute onset of pelvic pain and musculoskeletal injuries. When prescribing these medications, it is important to consider adverse gastrointestinal side effects and blood thinning properties. These medications may need to be discontinued due to lack of response. Neuropathic pain medications can be effective (gabapentin, pregabalin, serotonin-norepinephine reuptake inhibitors, tricyclic antidepressants), especially when there is a neurogenic component to the patient’s pelvic pain. These medications have to be individualized for the patient given their side effects. Serotonin-norepinephrine reuptake inhibitors, such as duloxetine, may help reduce pain and improve sleep.

Muscle relaxants are also commonly used for symptom relief when pelvic floor muscle spasm is contributing to the patient’s pain. Oral muscle relaxants may help reduce overall muscle tone that is perceived to be painful but are not specific for the pelvic floor. Cyclobenzaprine, when taken daily, has an effect similar to the tricyclic antidepressants. It may be best prescribed at night given its sedative side effects. Of note, patients should be monitored for urinary retention when on cyclobenzaprine. Certain muscle relaxants, such as diazepam and baclofen can be made into a suppository or compounded cream and used intravaginally. Vaginal diazepam is generally well tolerated, with the major side effect being drowsiness. In a retrospective review by Carrico and Peters, 67% of women reported no adverse effects from the vaginal diazepam, while 33% of women reported some drowsiness.¹¹ Topical lidocaine can also been used in the treatment of severe penetrative dyspareunia. This medication is especially useful when used prior to intercourse. Lidocaine gel can also be used internally prior to physical therapy for patients that have trouble tolerating internal myofascial release of the pelvic floor muscles.

Physical Therapy

Pelvic floor physical therapy, including dilators, pelvic floor muscle strengthening and relaxation exercises, intravaginal massage techniques and biofeedback, can help to correct muscle imbalance, improve blood flow, and increase flexibility of paravaginal tissue.¹² In a small prospective study of patients with vestibulodynia, patients who completed pelvic floor therapy had significant improvement in overall sexual function and reduction in pain with intercourse.¹²

Pelvic floor physical therapy is used for myofascial pain and dysfunction with goals to restore muscle imbalance, improve function and reduce pain. Often, therapy combines neuromuscular reeducation and soft tissue mobilization. Exercises to restore normal muscle movement patterns, strength and range of motion can be utilized to help reeducate the patient.⁷ Biofeedback can provide objective feedback about muscle activation with activity and at rest. Trigger point manual release, acupressure, muscle energy, and strain-counterstrain can be used for myofascial trigger points. Trigger points can be located in the pelvic floor muscles or the abdominal wall musculature. It is also important to include treatment of other disorders within the hip-spine-pelvis complex in the therapy prescription.

Psychotherapy

It is important to address any co-morbid depression and/or anxiety. Patients should be screened for depression, anxiety and history of abuse. Appropriate patients should be referred to psychiatry, psychology, or cognitive behavioral therapy.

Interventional Management

When therapeutic and medical management fails, alternative interventional pain management procedures may be required.

Nerve Blocks

Neurolytic blocks of ganglion can be used effectively in some cases. The ganglion impar, or ganglion of Walther, is found on the ventral surface of the coccyx where it forms the caudal origin of the bilateral sympathetic chain. It has sympathetic innervation to the perineal and anal regions and block of this innervation can disrupt afferent sympathetic and nociceptive signals from that area.¹³

Superior hypogastric plexus blocks (SHPB) with fluoroscopy or computed tomography (CT) guidance also have been used in malignant and non-oncological chronic pelvic pain.¹⁴ The superior hypogastric plexus is a retroperitoneal structure extending below the aortic bifurcation in association with the common and internal iliac vessels. It innervates much of the pelvic viscera including the bladder, urethra, uterus, vagina, vulva, perineum, prostate, penis, testes, rectum and descending colon.

Pelvic Floor Trigger Point Injections

Trigger point injections have been described in myofascial pain, including CPP.¹⁵ These injections can be beneficial when a patient presents with pelvic pain and is found to have one or more myofascial trigger points in the pelvic floor muscles. Trigger point injections are generally not used as a first line treatment or monotherapy but are generally more beneficial when used alongside physical therapy, medication management and behavioral therapy.¹⁵

Pelvic Floor Botulinum Toxin Injections

For patients with refractory pelvic floor muscle spasm, botulinum toxin has been utilized to decrease spasm, therefore reducing pelvic pain. Botulinum toxin type A blocks the cholinergic transmission at the neuromuscular junction. Abbott et al.¹⁶ performed a double-blinded randomized, placebo-controlled trial in patients with CPP and demonstrated a significant decrease in dyspareunia and non-menstrual pain in the botulinum toxin group. In addition, they reported a significant reduction in pelvic floor pressure in the botulinum toxin group when compared to the pre-injection values. It is important to note that there were no statistically significant differences demonstrated between the groups in any of the previously mentioned parameters.

Neuromodulation

Neuromodulation has also used as a treatment for CPP. Neuromodulation is a nondestructive, neuromodulory technique that delivers electrical stimulation to the spinal cord or peripheral nerves for the treatment of chronic pain. Patients with CPP may benefit from spinal cord stimulation, sacral stimulation or peripheral nerve stimulation. In particular, tibial nerve stimulation, which is an in-office weekly procedure, has shown some promise in the treatment of pelvic pain, fecal incontinence and overactive bladder.

Conclusion

Pelvic pain is traditionally recognized as a difficult condition to treat. With increased knowledge of the pelvic floor as a major contributor to pelvic pain, successful treatment can involve a multifactorial and multidisciplinary approach.

Biography

Sarah K. Hwang, MD, is Assistant Professor of Clinical PM&R, Department of Physical Medicine and Rehabilitation, University of Missouri Health Care.

Contact: hwangsa@health.missouri.edu