30 Chronic Pelvic Pain

Khara M. Simpson

Wen Shen

Chronic pelvic pain (CPP) is a common and often difficult problem, with direct medical costs estimated at $1 to $2 billion per year in the United States.

TYPES OF PELVIC PAIN

There are no standard diagnostic criteria, but a reasonable definition of CPP is cyclic or noncyclic pain in the lower abdomen, pelvis, lower back, or buttocks of at least 6 months duration that causes functional disability and motivates the patient to seek medical help. Because of varied definitions, the epidemiology and natural history of CPP are not well described. Acute pelvic pain can be defined with the same criteria but lasts can be helpful in recording subjective and objective data and may increase the efficiency of initial data gathering. Useful resources are available from the International Pelvic Pain Society (IPPS) at www.pelvicpain.org. Pain questionnaires are helpful in allowing the patient to develop a coherent and relevant narrative before appearing at the office and allow rapid review of symptoms, permitting the interview to focus on pain issues. A personal body pain map is extremely helpful in focusing the differential and examination.

• Adequate time should be allotted for a complete medical and psychosocial history without rushing the patient.

• Establish a detailed understanding of the intensity, location, character, and duration of the pain and any association with intercourse, menstruation, defecation, recent or distant surgery, radiation treatments, or abdominopelvic infections. Precipitating and relieving factors should be reviewed.

• Screening for physical or sexual abuse, domestic violence, and other psychosocial stressors (e.g., death of loved one, divorce) should be completed. Twenty percent to 60% of patients with CPP report a history of sexual or childhood abuse. A complete mental health history and depression screening are helpful; mood and personality disorders are frequently comorbid with CPP. It is not clear whether these problems are a cause or result of pain. Increased depression scores, however, correlate with increased pain scores, so simultaneous treatment is most effective.

• Current, usual, and worst pain can be recorded using a pain scale (e.g., visual analogue scale). Associated symptoms such as weight loss, hematochezia, and perimenopausal/postmenopausal bleeding should prompt a thorough investigation for malignancy.

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• The physical exam begins with a general and neurologic assessment. Fully explain the plan and exam techniques to relieve anxiety and promote patient cooperation and comfort. The IPPS physical exam form or similar tools may be useful for recording the complete assessment. The exam should help narrow the differential, rule out systemic disease or neoplasm, and suggest additional testing.

• Evaluate the general appearance, including dress, nutrition, posture, apparent age, gait, and pain behaviors. Evaluate posture (both seated and standing) and gait (for any hip height and leg length discrepancy).

• Ask the patient to indicate the precise location of her pain. If she is able to use a single finger, a discrete source is more likely than if she uses a broad sweeping motion of the entire hand.

• Note the presence of scars or hernias on abdominal exam. Gently attempt to elicit pain with palpation of the skin, fascia, or muscle. Especially note any reproducible tenderness. Appropriate trigger point mapping should be performed if fibromyalgia is in the differential.

• Look for Carnett sign (i.e., increased abdominal tenderness when the patient lifts her head and shoulders in the supine position) suggesting abdominal wall rather than intra-abdominal pathology. Pain with the Beatty maneuver (i.e., thigh abduction against resistance) may suggest piriformis syndrome. The obturator sign (i.e., pain with flexion and internal rotation of the hip while lying supine) and the psoas sign (i.e., pain with hip flexion against resistance) can indicate inflammation or dysfunction within those muscles. The straight leg raise test evaluates radiculopathy or intervertebral disc disease. The FAbER test (i.e., pain with flexion/abduction/external rotation of the hip) assesses hip and sacroiliac joint pathology.

• A thorough neurologic examination, including sensation, muscle strength, and reflexes, may be required. Examine the spine for scoliosis while the patient is sitting, standing, walking, and bending at the waist.

• The gynecologic exam starts with external observation and then palpation with cotton swabs to define hyperesthetic areas (even if the skin appears normal). Colposcopic examination of the vulva and vestibule may be helpful. Light touch and pinprick sensation testing of the vulva is required.

๎ Start the internal examination with a single-digit vaginal exam. Assess the vestibule, vaginal walls, rectum, urethra, bladder trigone, pubic arch, pelvic floor muscles, cervix, and vaginal fornices. Initial assessment of the uterus and adnexa are performed with a single digit as well.

๎ Visual inspection of the vaginal vault can begin with a single speculum blade. Assess the vaginal cuff or cervix, cervical os, paracervix, and vaginal mucosa.

๎ Finally, perform a bimanual exam of the uterus, adnexa, and other pelvic contents followed by rectovaginal exam.

Imaging and Laboratory Testing

• Imaging and diagnostic testing are tailored to the differential.

• Pelvic ultrasonography is of little benefit unless uterine or adnexal pathology is suspected. Transvaginal imaging may better assess the pelvic structures than the transabdominal approach.

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• Magnetic resonance imaging can be helpful in selected cases, especially if adenomyosis is suspected.

• Plain x-ray of the chest, spine, abdomen, or joints or computed tomography scan is rarely indicated.

• Colonoscopy can assess colorectal cancer, inflammatory bowel disease, diverticulosis, and invasive endometriosis. It is indicated in cases with persistent diarrhea or hematochezia.

• Cystoscopy and evaluation for interstitial cystitis/bladder pain syndrome are frequently indicated early in the workup.

• Laboratory testing is guided by the history and physical and may include urine pregnancy test, vaginal pH and wet mount, gonorrhea and chlamydia polymerase chain reaction, complete blood count, erythrocyte sedimentation rate, thyroidstimulating hormone, rapid plasma reagin, hepatitis B surface antigen, HIV test, urinalysis/microscopy, and urine culture. There is no standard laboratory panel for CPP. Serum cancer antigen 125 testing is not useful unless a cancer workup is initiated. Endocrine testing for follicle-stimulating hormone, estradiol, and gonadotropin-releasing hormone (GnRH) stimulation test may be indicated for suspected ovarian remnant syndrome.

Laparoscopy and Consults

• Although pelviscopy is performed for more than 40% of CPP cases, it should be employed only when noninvasive evaluation is completed and for cases in which a diagnosis can be reasonably anticipated. Laparoscopy is not a substitute for a complete history and physical or for diagnoses that can be made without a procedure.

• Selected evaluation by neurology, gastroenterology, anesthesiology, urology, psychiatry, or physical therapy consultants can provide important multidisciplinary perspective and assist in forming a complete treatment plan. Often, patients have been through a long, tedious, and piecemeal evaluation by multiple providers followed by redundant diagnostic and treatment failures. Performing a complete and multidisciplinary assessment from the start may reach a successful outcome more efficiently and reassure a demoralized and anxious patient. In addition, some tests are only appropriately obtained via consultation, such as nerve conduction studies or electromyography, if they are necessary.

DIFFERENTIAL DIAGNOSIS OF PELVIC PAIN

The differential diagnosis of pelvic pain is extensive, and many patients deserve multiple diagnoses.

• Selected causes of CPP are listed in Table 30-1. Previously undiagnosed medical illness should also be considered, such as neoplasia, sickle cell disease, hyperparathyroidism, urolithiasis, lead/mercury intoxication, lactose intolerance, chronic constipation, chronic appendicitis, and chronic fatigue syndrome.

• The clinical satisfaction of applying Occam razor and assigning only one unifying diagnosis after a thorough workup for CPP is not likely; management of multiple disease processes is often required. The following disorders, in addition to being primary etiologies, are frequently comorbid with CPP and deserve special consideration.

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• Dysmenorrhea is reported in up to 80% of women with CPP. It is characterized by cramping pelvic or suprapubic pain that radiates to the lower back or thighs, often with mood or behavioral changes. Nausea/vomiting, diarrhea, irritability, and fatigue may be present. The pathophysiology is inflammatory prostaglandin release upon progesterone withdrawal at the end of the menstrual cycle.

• Endometriosis is diagnosed in up to 70% of pelvic pain patients, although biopsy-proven disease is present in perhaps only 30%. See Chapter 38. Up to 80% of patients treated with laparoscopic excision of endometriosis have short-term pain relief, but less than half of those continue to report improved pain scores at 1 year.

• Irritable bowel syndrome (IBS) is a primary or secondary diagnosis in 40% to 60% of patients with CPP. Associated symptoms of IBS include abdominal distention, bloating, fatigue, and headache. Symptoms are sometimes worse before menses. Although often comorbid with CPP, this is often a diagnosis of exclusion when considering a primary etiology for CPP.

• Pelvic adhesions are eventually diagnosed in about 25% of women with CPP, but a causal relationship is debatable. Pain localization, but not intensity, correlates with the presence of isolated adhesions detected during pelviscopy. Adhesiolysis has not been proven to provide dramatic relief.

• Interstitial cystitis/bladder pain syndrome is a chronic inflammatory disorder with aspects of a chronic visceral pain syndrome that frequently coexists with other causes of CPP. Diagnosis is made by cystoscopy and hydrodistention under anesthesia, with findings of glomerulations or Hunner ulcers. Treatment is with oral pentosan sulfate (Elmiron), antihistamines, and low-dose tricyclic antidepressants (e.g., amitriptyline). Bladder installation of an anesthetic cocktail of lidocaine, heparin, steroids, and sodium bicarbonate can provide pain relief on an intermittent or continuous basis.

• Pelvic congestion syndrome (symptomatic varicose veins of the pelvis) can be objectively diagnosed by transcervical pelvic venogram. Randomized trials show correlation between venogram scores and pain, with improvement after treatment. T reatment options include hormonal therapy (progestins, combined oral contraceptives), pelvic vein embolization, and hysterectomy.

• Myofascial pain is comorbid with 10% to 20% of CPP. Physical therapy is the mainstay of treatment. Selective serotonin reuptake inhibitors (SSRIs) and muscle relaxants may be useful adjuncts.

• Dyspareunia can be a primary or secondary symptom in CPP. Additionally, the psychological effect of CPP on relationships and sexual function should be addressed in the evaluation and treatment plan.

• Low back pain is often a separate treatable problem that can exacerbate CPP.

MANAGEMENT OF CHRONIC PELVIC PAIN

Management of CPP depends on the etiology and comorbidities (see Table 30-1). The best outcomes may come from a rehabilitation approach with a consistent provider, personalized multidisciplinary treatment, extensive patient education and counseling, and regular office visits. The physician must be open-minded and supportive but offer realistic and explicit goals for therapy. The patient may be desperate for a

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P.398 P.399 P.400 P.401 P.402 P.403 diagnosis and may have exaggerated, nonanatomic pain or nonphysiologic sensations. Tailor treatments to the patient and address the underlying etiology, associated pain syndrome, psychological needs, and physical therapy concerns. Develop an accurate problem list and plan of management for each pain component. There is no strong evidence to support medical versus surgical management. At 1 year, about half of surgical patients report improved pain, whereas the rest report no change or worsening symptoms; similar proportions have been reported with medical treatment.

TABLE 30-1 Differential Diagnosis of Chronic Pelvic Pain

pathology

of secondary causes

medications, nerve block, or surgical decompression for

severe cases.

This list is not exhaustive but represents the multiple systems and variety of diagnoses in the workup of CPP. General treatments are listed only to indicate possible therapies used for each condition.

^aAlso include a broader psychiatric differential such as bipolar disorders, personality disorders, depression, and substance abuse. H&P, history and physical; OCPs, oral contraceptive pills; GnRH, gonadotropin-releasing hormone; MRI, magnetic resonance imaging; NSAIDs, nonsteroidal antiinflammatory drugs; IUD, intrauterine device; LUNA, laparoscopic uterosacral nerve ablation; FSH, follicle-stimulating hormone; PID, pelvic inflammatory disease; STD, sexually transmitted disease; PCR, polymerase chain reaction; TCA, tricyclic antidepressants; POP-Q, pelvic organ prolapse quantification; AXR, abdominal x-ray; GI, gastrointestinal; CT, computed tomography; DMSO, dimethyl sulfoxide; PMP, postmenopausal; CNS, central nervous system; EMG, electromyography; SSRI, selective serotonin reuptake inhibitors; DEXA, dual energy x-ray absorptiometry.

Medical Therapy

• Medical therapies are selected to correct or arrest underlying pathology and to relieve pain symptoms. Analgesics should be dosed on noncontingent schedules with additional breakthrough pain treatment as needed. Acetaminophen is a good first-line analgesic.

• Nonsteroidal anti-inflammatory drugs (NSAIDs) (e.g., ibuprofen, aspirin, naproxen) are a mainstay of pain treatment, especially if inflammation is present. Contraindications to NSAID treatment (e.g., liver disease for acetaminophen, renal failure or peptic ulcer disease for NSAIDs) must be excluded. Prescribe medications with adequate dosing and frequency. Higher than usual doses may be required.

• Opioid analgesia with oral tramadol, codeine, oxycodone, and hydrocodone may be indicated. Intravenous medications are rarely indicated for CPP. Combination long- and short-acting opioids can be beneficial. A chronic pain specialist can be helpful when initiating or titrating drug therapy.

• Hormonal treatment is frequently used for endometriosis and dysmenorrhea.

๎ Continuous oral contraceptive pills and GnRH agonists (e.g., goserelin, Lupron Depot) prevent ovulation and may help pain associated with menses, including endometriosis.

๎ There is good evidence that medroxyprogesterone 50 mg orally each day helps control endometriosis symptoms. Depot medroxyprogesterone acetate 150 mg intramuscularly every 3 months is another option.

• Thiamine (vitamin B₁) 100 mg orally daily, vitamin E supplementation, and oral magnesium supplementation are possible nutritional approaches to dysmenorrhea, although effectiveness of data is limited.

• SSRI antidepressants (e.g., fluoxetine, sertraline) have not been shown to work well for pain, but they are useful for treatment of comorbid depression or anxiety disorders that can increase pain perception. Serotonin norepinephrine reuptake inhibitors (e.g., duloxetine, venlafaxine, milnacipran) are effective for depression, anxiety, and neuropathic pain.

• Tricyclic antidepressants (e.g., amitriptyline, nortriptyline) are the most effective neuropathic pain medications; they may act by lowering the pain threshold (see Table 30-1). Antiseizure medications (e.g., gabapentin, pregabalin, carbamazepine) are useful for neuropathic pain.

• Muscle relaxants (e.g., cyclobenzaprine, baclofen) are sometimes useful for muscle spasm, but they should be used as adjuncts or second- line agents with nonsteroidal drugs until a course of physical therapy can be completed.

Surgical Treatment

• Surgical therapies are indicated for specific diagnoses or for patients who do not improve with medical treatments.

• Surgical treatment of severe endometriosis or adhesions (i.e., adhesiolysis) can be curative in some cases. Patients should understand that there is a strong possibility

P.404 that additional therapies or medication may be required and that the surgical procedure can lead to unforeseen complications.

• Laparoscopic uterosacral nerve ablation (LUNA) has been used for dysmenorrhea in patients with endometriosis who desire to maintain fertility, but several controlled clinical trials show that it is ineffective.

• The superior hypogastric plexus is excised with presacral neurectomy. There is some evidence showing modest pain reduction for patients with midline pelvic pain due to dysmenorrhea/endometriosis. The procedure can lead to complications such as ureteral injury and uncontrolled bleeding and should be performed by experienced surgeons only.

• Pudendal nerve release from Alcock canal by transgluteal or transperineal approach is performed for some patients with pudendal nerve entrapment, although there are only limited data by which to judge the procedure.

• Hysterectomy can be performed for patients with evidence of uterine pain (e.g., adenomyosis, some cases of endometriosis) who have completed their childbearing and have not responded well to medical management. Sixty percent to 80% of appropriately selected patients report pain improvement.

Other T reatment Options

• Neurologic/pain anesthesia therapies are useful for CPP that can be discretely localized or is due to a specific peripheral nerve injury. Local anesthetic (e.g., lidocaine) can be injected for cutaneous nerve or trigger point block. Longer acting peripheral nerve blocks can benefit some patients. Botulinum toxin injection can improve unresponsive spasmodic muscular disorders. Referral to an anesthesia pain specialist may be warranted.

• Physical therapy by a provider with expertise in pelvic floor disorders can be helpful in both evaluation and treatment of CPP. Stretching, strengthening, hot/cold applications, pelvic floor training, transcutaneous electrical nerve stimulation, and biofeedback can be used.

• Psychotherapy is almost always beneficial for a patient with chronic pain. Psychological disorders can be diagnosed and managed, and cognitive behavioral therapy, psychotherapy, or counseling can benefit almost all CPP patients. If abuse is reported, the patient should be referred for psychological counseling regardless of the degree to which that history contributes to her pain. In some cases, referral for family or relationship counseling may be indicated as well.

• AlternativeZholistic therapies such as massage, relaxation techniques, and acupuncture may be appropriate adjunctive interventions for many patients and enhance the effectiveness of traditional medical or surgical therapy. These should be discussed with the patient and integrated in her treatment plan early on.

SUGGESTED READINGS

American College of Obstetricians and Gynecologists. ACOG practice bulletin no. 51: chronic pelvic pain. Obstet Gynecol 2004;103:589-605.

Bettendorf B, Shay S, Tu F. Dysmenorrhea: contemporary perspectives. Obstet Gynecol Surv 2008;63(9):597-603.

Bhutta HY, Walsh SR, Tang TY, et al. Ovarian vein syndrome: a review. Int J Surg 2009;7: 516-520.

Hillis SD, Marchbanks PA, Peterson HB. The effectiveness of hysterectomy for chronic pelvic pain. Obstet Gynecol 1995;86(6):941-945.

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Howard FM. Chronic pelvic pain. Clinical gynecologic series: an expert's view. Obstet Gynecol 2003;101:594-611.

Lamvu G, Williams R, Zolnoun D, et al. Long-term outcomes after surgical and nonsurgical management of chronic pelvic pain: one year after evaluation in a pelvic pain specialty clinic. Am J Obstet Gynecol 2006; 195:591-600.

Latthe P, Mignini L, Gray R, et al. Factors predisposing women to chronic pelvic pain: systematic review. Br Med J 2006;332(7544):749-755.