Imaging studies of the pelvic floor

Evaluation of constipation

The evaluation of the chronically constipated patient is multifaceted and challenging. Many clinicians define constipation according to the latest Rome III diagnostic criteria for functional gastrointestinal disorders. Female sex, older age, low fiber diet, a sedentary life style, malnutrition, polypharmacy, and a lower socioeconomic status have all been identified as risk factors for functional constipation. In elderly patients, it is important to rule out a colonic malignancy as the cause of constipation. The initial evaluation of the constipated patient includes a detailed history to elicit symptoms distinguishing slow transit constipation from obstructive defecation. Slow transit and obstructive defecation are the two major subtypes of functional constipation. In addition, the clinician should identify any secondary causes of constipation. The office examination of the constipated patient includes an abdominal, perineal, and a rectal exam. Many patients improve with lifestyle modification. When dietary interventions and lifestyle modifications fail, many diagnostic studies are available to further evaluate the constipated patient. Sitzmark transit study, nuclear scintigraphic defecography, electromyography, anorectal manometry, balloon expulsion test, paradoxical puborectalis contraction, cinedefecography, and dynamic magnetic resonance imaging defecography have all been used to diagnose the underlying causes of functional constipation.

Pelvic floor imaging

Pelvic floor ultrasound is a valuable adjunct in elucidation of cause, diagnosis, and treatment of pelvic floor disorders. Three-dimensional ultrasound specifically has been shown to have many advantages over conventional imaging modalities. Proper evaluation of pelvic floor muscle function, strength, and integrity is an important component of diagnosis and treatment of pelvic floor disorders. The pelvic floor muscle training used to change the structural support and strength of muscle contraction requires clinicians to be able to conduct high-quality measurements of pelvic floor muscle function and strength. Ultrasound is a useful modality to assess the pelvic floor and its function. As practitioners become more familiar with the advantages and capabilities of ultrasound, this tool should become part of routine clinical practice in evaluation and management of pelvic floor disorders.

The evaluation of constipation

Constipation is a major medical problem in the United States, affecting 2% to 28% of the population. Individual patients may have different conceptions of what constipation is, and the findings overlap with those in other functional gastrointestinal disorders. In 1999, an international panel of experts laid out specific criteria for the diagnosis of constipation known as the Rome II criteria. When patients present with complaints of constipation, a complete history and physical examination can elicit the cause of constipation. It is imperative to rule out a malignancy or other organic causes of the patient's symptoms prior to making the diagnosis of functional constipation. Many patients' symptoms can be relieved with lifestyle and dietary modification, both of which should be implemented before other potentially unnecessary tests are performed. Functional constipation is divided into two subtypes: slow transit constipation and obstructive defecation. Because many different terms are used interchangeably to describe these subtypes of constipation, physicians need to be comfortable with the language. Slow transit constipation is due to abnormal colonic motility. The diagnosis is made with the use of a colonic transit study. We continue to use a single-capsule technique as first described in the literature, but modifications of the capsule technique as well as scintigraphic techniques are validated and can be substituted in place of the capsule. Obstructive defecation is a much more complex problem, with etiologies ranging from rare diseases such as Hirschsprung's to physiologic abnormalities such as paradoxical puborectalis contraction. To fully evaluate the patient with obstructive defecation, anorectal manometry, defecography, and electromyography should be utilized. The different techniques available for each test are fully covered in this article. When evaluating each patient with constipation, it is important to keep in mind that the disease may be specific to one subtype or a combination of both subtypes. Because it is difficult to differentiate the subtypes from the patient's history, we feel it is imperative to evaluate patients fully for both slow transit and obstructive defecation prior to any surgical intervention. Furthermore, we have described many tests that need to be applied to one's population of patients on the basis of the capabilities and expertise the institution offers.

Comparison of supine magnetic resonance imaging with and without rectal contrast to fluoroscopic cystocolpoproctography for the diagnosis of pelvic organ prolapse

PURPOSE

To compare supine magnetic resonance imaging (MRI), with and without rectal contrast, with fluoroscopic cystocolpoproctography (CCP) for the diagnosis of pelvic organ prolapse.

MATERIALS AND METHODS

Supine MRI and CCP studies were reviewed in 82 patients. All patients were women with an average age of 58.8 years, and the studies were done a mean of 25 days apart. Magnetic resonance imaging was performed with rectal contrast (n = 35) and without rectal contrast (n = 47). Fluoroscopic cystocolpoproctography was performed with rectal (n = 82), vaginal (n = 82), small bowel (n = 81), and bladder (n = 78) contrast, and images were corrected for magnification. Each study was independently reviewed by 2 readers, and outcome variables were presence/absence of cystocele, vaginal prolapse, enterocele, sigmoidocele, and anterior rectocele. Sigmoidoceles were included with enteroceles for data analysis.

RESULTS

For the entire patient group, the prevalence of cystoceles was 89% on CCP and 80% on MRI; vaginal prolapse was 81% on CCP and 56% on MRI; enteroceles, 38% on CCP and 24% on MRI; and anterior rectoceles, 45% on CCP and 37% on MRI. There were significantly more cystoceles (odds ratio [OR] 4.7, P = 0.003), vaginal prolapses (OR 5.2, P < 0.0005), and enteroceles (OR 3.8, P< 0.0005) on CCP than on MRI. For MRI with rectal contrast versus CCP, the prevalence of cystoceles was 94% on CCP and 91% on MRI; vaginal prolapse, 74% on CCP and 70% on MRI; enteroceles, 36% on CCP and 19% on MRI; and anterior rectoceles, 51% on CCP and 59% on MRI. There was statistical significance only for enteroceles, more of which were found on CCP (OR 7.4, P = 0.003). For MRI without rectal contrast versus CCP, the prevalence of cystoceles was 85% on CCP and 72% on MRI; vaginal prolapse, 86% on CCP and 46% on MRI; enteroceles, 40% on CCP and 28% on MRI; and anterior rectoceles, 39% on CCP and 21% on MRI. There were significantly more cystoceles (OR 6.6, P = 0.003), vaginal prolapses (OR 20.8, P < 0.0005), enteroceles (OR 2.9, P = 0.015), and rectoceles (OR 4.9, P = 0.001) on CCP than on noncontrast MRI.

CONCLUSIONS

Magnetic resonance imaging without rectal contrast showed statistically fewer pelvic floor abnormalities than CCP. Except for enteroceles, MRI with rectal contrast showed statistically similar frequency of pelvic organ prolapse as CCP.

Translabial ultrasound assessment of the anal sphincter complex: normal measurements of the internal and external anal sphincters at the proximal, mid-, and distal levels

The purpose of this study was to measure the internal and external anal sphincters using translabial ultrasound (TLU) at the proximal, mid, and distal levels of the anal sphincter complex. The human review committee approval was obtained and all women gave written informed consent. Sixty women presenting for gynecologic ultrasound for symptoms other than pelvic organ prolapse or urinary or anal incontinence underwent TLU. Thirty-six (60%) were asymptomatic and intact, 13 symptomatic and intact, and 11 disrupted. Anterior-posterior diameters of the internal anal sphincter at all levels and the external anal sphincter at the distal level were measured in four quadrants. Mean sphincter measurements are given for symptomatic and asymptomatic intact women and are comparable to previously reported endoanal MRI and ultrasound measurements.

Pelvic prolapse: static and dynamic MRI

Pelvic magnetic resonance is a simple and non-invasive imaging technique for dynamic and static assessment of the pelvic floor. The morphology of the support system is assessed by T2-weighted images. Dynamic sequences are used to assess pelvic prolapse. In this study we illustrate the normal and pathologic features of the levator ani muscle which represents the main active support of pelvic organs. Furthermore we describe the different types of prolapses, floor by floor, and the different staging techniques.

Dynamic MR imaging of female organ prolapse

MR imaging is a viable technique for evaluating pelvic organ prolapse. Dynamic imaging with adequate increase in abdominal pressure is necessary for a successful study. Rectal contrast for patient defecation is easy to administer and also allows for the diagnosis of rectal abnormalities. Additional work is needed on the soft tissue changes of prolapse and grading criteria for MR.

Diagnostic imaging of pelvic floor dysfunction

Pelvic floor dysfunction encompasses a variety of fascial and anatomic defects that can include a combination of cystocele, rectocele, uterine prolapse, enterocele and vault prolapse. Accurate diagnosis of the coexisting abnormalities is essential in planning reconstructive procedures so that the risks of recurrence and reoperation can be minimized. At this time, dynamic magnetic resonance imaging is the study of choice to evaluate the female pelvis and delineate the possible components of pelvic floor dysfunction.

Real-time intraoperative ultrasound guidance: the transrectal approach

OBJECTIVE

To assess the role of real-time transrectal ultrasound guidance in complicated gynecologic procedures.

DESIGN

In 1998-99, real-time guidance with transrectal ultrasound was utilized in our department to assist the gynecologic surgeon in two procedures: completing the evacuation of the uterine cavity after identification of uterine wall perforation during first trimester termination of pregnancy, and drainage of infected vaginal vault hematoma following hysterectomy.

RESULTS

The technique was applied for 11 patients, six abortions and five infected hematomas. All the procedures were completed without any further complications and the patients were discharged on the following day. Follow-up was uneventful.

CONCLUSIONS

On-line intraoperative transrectal ultrasound can effectively provide real-time assistance to the gynecologic surgeon during complicated pelvic procedures.