The muscles of the pelvic floor

The Role of Pelvic Floor Muscle Training in the Conservative and Surgical Management of Female Stress Urinary Incontinence: Does the Strength of the Pelvic Floor Muscles Matter?

The purpose of this review is to provide an in-depth overview of the role of pelvic floor muscle (PFM) training in the management of stress urinary incontinence (SUI). The definition, epidemiology, and pathogenesis of SUI are described. We review the anatomy of the PFM and the importance of PFM strength in maintaining urinary continence and establishing normal voiding function. A brief description of the surgical options currently available for SUI and the existing data regarding the role of perioperative PFM training for SUI are included. Critical research questions to better evaluate and assess PFM training during the perioperative period are proposed. Promising novel approaches in the treatment of SUI are also presented. This review is useful for physiatrists, urogynecologists, female urologists, and nurse practitioners who specialize in the management and treatment of women with SUI. LEVEL OF EVIDENCE: IV.

Anatomy and nerve supply of the pelvic floor

In order to guarantee urinary and fecal continence as well as correct pelvic statics, the perfect neuroanatomical integrity of the pelvic floor muscles is mandatory. As Dickinson stated: “There is no considerable muscle in the body whose form and function are more difficult to understand than those of the levator ani, and about which such nebulous impressions prevail”. Clinical implications of pelvic floor anatomy and nerve supply are evident: a denervation of this muscle group and the consequent muscle dysfunction could result in urinary and/or fecal incontinence, as well as pelvic organ prolapse.

Voiding difficulties in the elderly

Voiding difficulties are more common in the elderly. This occurs because of physiological changes such as replacement of muscle fibres with collagen, from life effect insults such as the effects of childbirth, lead to a reduction in contractility and changes in the nerve supply from cholinergic to NANC fibres lead to a change in sensation leading to a delay in first sensation. Symptoms are often similar to those of overactive bladder and the history in older women should include those of hesitancy and poor flow. Likewise, the diagnosis should be considered in women presenting with recurrent urinary tract infections. A failure to consider voiding difficulties can precipitate a crisis and simple strategies such as teaching self-catheterization and using estrogen cream may prevent problems occurring. When acute problems occur, catheterization is required and a review of precipitating factors may identify medications contributing to the condition. The mainstay for treatment, however, remains draining with an indwelling catheter or clean intermittent clean catheterisation.

Electromyographic evaluation of pelvic floor muscles in pregnant and nonpregnant women

INTRODUCTION AND HYPOTHESIS

We compared the maximal voluntary contraction (MVC) and strength of pelvic floor muscles (PFM) of pregnant and nonpregnant women using surface electromyography (SEMG).

METHODS

Fifteen pregnant primiparous women and 15 nulliparous nonpregnant women were evaluated. The healthy pregnant women were in the third trimester of pregnancy with a single fetus and did not have any neuromuscular alterations. The nonpregnant women did not present with PF dysfunctions and, as with the pregnant women, did not have any previous gynecological surgeries or degenerative neuromuscular alterations. The evaluation methods used were digital palpation (Oxford Grading Scale, which ranges from 0 to 5) and SEMG. In the EMG exam, MVC activity was evaluated, and the better of two contractions was chosen. Before the evaluation, all women received information about PFM localization and function and how to correctly contract PFM.

RESULTS

In the EMG evaluation, MVC was significantly greater in the nonpregnant group (90.7 μv) than in the pregnant group (30 μv), with p < 0.001. The same results were observed after vaginal palpation, measured by the Oxford scale, which presented an average of 2.1 in the pregnant group and 4.5 in the nonpregnant group (p = 0.005).

CONCLUSION

In comparison to nulliparous women, pregnant women demonstrated worse PFM function with decreased strength and electrical activity.

Pelvic floor muscles and the external urethral sphincter have different responses to applied bladder pressure during continence

OBJECTIVES

To determine the functional innervation of the pelvic floor muscles (PFM) and whether there is PFM activity during an external pressure increase to the bladder in female rats.

METHODS

Thirty-one female adult virgin Sprague-Dawley rats received an external increase in bladder pressure until urinary leakage was noted while bladder pressure was recorded (leak point pressure [LPP]) under urethane anesthesia. Six of the rats underwent repeat LPP testing after bilateral transection of the levator ani nerve. Another 6 rats underwent repeat LPP testing after bilateral transection of the pudendal nerve. Simultaneous recordings of PFM (pubo- and iliococcygeus muscles), electromyogram (EMG), and external urethral sphincter (EUS) EMG were recorded during cystometry and LPP testing.

RESULTS

Thirteen rats (42%) showed tonic PFM EMG activity during filling cystometry. Eighteen rats (58%) showed no tonic PFM EMG activity at baseline, but PFM EMG could be activated by pinching the perineal skin. This activity could be maintained unless voiding occurred. The external increase in bladder pressure caused significantly increased EUS EMG activity as demonstrated by increased amplitude and frequency. However, there was no such response in PFM EMG. LPP was not significantly different after levator ani nerve transection, but was significantly decreased after pudendal nerve transection.

CONCLUSIONS

PFM activity was not increased during external pressure increases to the bladder in female rats. Experimental designs using rats should consider this result. The PFM, unlike the EUS, does not contribute to the bladder-to-urethra continence reflex. PFM strengthening may nonetheless facilitate urinary continence clinically by stabilizing the bladder neck.

Pelvic floor function in elite nulliparous athletes

OBJECTIVE

There is preliminary evidence linking long-term participation in high-impact exercise with poor performance in labor and increased incidence of stress urinary incontinence, which may be due to altered pelvic floor function. Recent work has shown that HIFIT (high-impact, frequent intense training) athletes have an increased cross-sectional area of the levator ani muscle group as visualized using magnetic resonance imaging (MRI). The aim of this study was to further characterize pelvic floor muscle function and pelvic organ descent in a nulliparous athletic population and compare it with non-athletic controls matched for age and body mass index, using three-dimensional/four-dimensional (3D/4D) pelvic floor ultrasound imaging.

METHODS

In this prospective comparative study translabial ultrasound imaging was used to assess pelvic floor anatomy and function in 46 nulliparous female volunteers (aged 19-39 years), 24 HIFIT and 22 controls. Two-dimensional (2D) and 3D translabial ultrasonography was performed on all subjects, after voiding and in the supine position. Descent of the pelvic organs was assessed on maximum Valsalva maneuver, whilst volume datasets were acquired at rest, during pelvic floor muscle contraction and during a Valsalva maneuver. Participants performed each maneuver at least three times and the most effective was used for evaluation.

RESULTS

HIFIT athletes showed a higher mean diameter of the pubovisceral muscle (0.96 cm vs. 0.70 cm, P < 0.01), greater bladder neck descent (22.7 mm vs. 15.1 mm, P = 0.03) and a larger hiatal area on Valsalva maneuver (21.53 vs. 14.91 cm(2), P = 0.013) compared with the control group. There were no significant differences in hiatal area at rest or on maximal voluntary contraction between the two groups.

CONCLUSION

HIFIT athletes show significant differences in several of the measured parameters for both function and anatomy of the pelvic floor. Further research into the impact of this altered function on childbirth and continence mechanisms is needed.

Displacement and recovery of the vesical neck position during pregnancy and after childbirth

AIMS

(i) To describe the displacement and recovery of the vesical neck position during pregnancy and after childbirth and (ii) to discriminate between compliance of the vesical neck supporting structures with and without pelvic floor contraction.

METHODS

We focussed on the biomechanical properties of the vesical neck supporting structures during pregnancy and after childbirth by calculating the compliance and the hysteresis as a result from of abdominal pressure measurements and simultaneous perineal ultrasound.

RESULTS

This study shows that compliance of the supporting structures remains relatively constant during pregnancy and returns to normal values 6 months after childbirth. Hysteresis, however, showed an increase after childbirth, persisting at least until 6 months post partum.

CONCLUSIONS

Vaginal delivery may stretch and or load beyond the physiological properties of the pelvic floor tissue and in this way may lead to irreversible changes in tissue properties which play an important role in the urethral support continence mechanism.

Innervation of the levator ani muscles: description of the nerve branches to the pubococcygeus, iliococcygeus, and puborectalis muscles

We described the innervation of the levator ani muscles (LAM) in human female cadavers. Detailed pelvic dissections of the pubococcygeus (PCM), iliococcygeus (ICM), and puborectalis muscles (PRM) were performed on 17 formaldehyde-fixed cadavers. The pudendal nerve and the sacral nerves entering the pelvis were traced thoroughly, and nerve branches innervating the LAM were documented. Histological analysis of nerve branches entering the LAM confirmed myelinated nerve tissue. LAM were innervated by the pudendal nerve branches, perineal nerve, and inferior rectal nerve (IRN) in 15 (88.2%) and 6 (35.3%) cadavers, respectively, and by the direct sacral nerves S3 and/or S4 in 12 cadavers (70.6%). A variant IRN, independent of the pudendal nerve, was found to innervate the LAM in seven (41.2%) cadavers. The PCM and the PRM were both primarily innervated by the pudendal nerve branches in 13 cadavers (76.5%) each. The ICM was primarily innervated by the direct sacral nerves S3 and/or S4 in 11 cadavers (64.7%).

Impact of pregnancy and childbirth on female rats’ urethral nerve fibers

This study aims to evaluate the urethral nerve fibers of adult female rats during pregnancy and after vaginal birth, cesarean section or simulated birth trauma. For immunohistochemical analysis of nerve fibers, 70 female rats were distributed in seven groups of ten female rats: group 1, control; group 2, pregnant; group 3, cesarean section; group 4, vaginal birth; group 5, virgin female rats with simulated birth trauma; group 6, cesarean section followed by simulation of birth trauma; and group 7, vaginal birth followed by simulation of birth trauma. The number of nerve fibers in groups 1, 2, and 3 were significantly higher than the other groups. Pregnancy and cesarean section did not cause alterations in the nerve fibers number. Vaginal birth and simulated birth trauma significantly decreased the number of nerve fibers in the female rats' middle urethra.

Pudendal nerve latency time in normal women via intravaginal stimulation

INTRODUCTION & OBJECTIVES

Studies of motor conduction for the efferent functional assessment of the pudendal nerve in women with pelvic dysfunctions have been conducted through researching distal motor latency times. The transrectal approach has been the classic approach for this electrophysiological examination. The objective of the present study is to verify the viability of the transvaginal approach in performing the exam, to establish normal values for this method and to analyze the influence of age, stature and parity in the latency value of normal women.

MATERIALS AND METHODS

A total of 23 volunteers without genitourinary pathologies participated in this study. In each, pudendal motor latency was investigated through the transvaginal approach, which was chosen due to patient's higher tolerance levels.

RESULTS

The motor response represented by registering the M-wave was obtained in all volunteers on the right side (100%) and in 13 volunteers on the left side (56.5%). The mean motor latency obtained in the right and left was respectively: 1.99 +/- 0.41 and 1.92 +/- 0.48 milliseconds (ms). There was no difference between the sides (p = 0.66). Latency did not correlate with age, stature or obstetric history. The results obtained in the present study were in agreement with those found by other researchers using the transrectal approach.

CONCLUSION

The vaginal approach represents an alternative for pudendal nerve distal motor latency time, with similar results to those achieved through the transrectal approach. Normative values obtained herein might serve as a comparative basis for subsequent physiopathological studies.

Anatomical and functional significance of urogenital hiatus in primary urodynamic stress incontinence

OBJECTIVES

To explore the correlations of anatomical and functional sonographic parameters of urogenital hiatus in primary urodynamic stress incontinence.

METHODS

We reviewed retrospectively our urodynamic database from July 1996 to June 2003 and identified subjects with primary urodynamic stress incontinence who had had anatomical assessment of the lower urinary tract and the central part of the pelvic floor by ultrasound. The morphological changes that had occurred in the central pelvic floor were determined by the measurement of genitohiatal angle, genitohiatal distance and anorectal angle.

RESULTS

A total of 396 women with a mean age of 48.8 +/- 10.7 (range, 26-82) years were included in the study. One hundred and eighteen subjects (29.8%) were postmenopausal. Stage I pelvic organ prolapse was found in 345 (87.1%) of the women, stage II in 19 (4.8%) and stage III in 32 (8.1%). The genitohiatal angle and genitohiatal distance were significantly and positively associated with resting and straining bladder neck angles. The genitohiatal angle was associated with bladder neck funneling and dependent cystocele during stress (r = 0.144, P = 0.016 and r = 0.140, P = 0.02, respectively), and it was negatively associated with functional profile length (r = -0.157, P = 0.012). The genitohiatal distance was negatively associated with functional profile length and maximum urethral closure pressure (r = -0.148, P = 0.018 and r = -0.227, P = 0.009, respectively). Increased genitohiatal distance was also related to a low Valsalva leak-point pressure (r = -0.199, P = 0.02). Multivariate analysis revealed that resting bladder neck angle was the independent factor for genitohiatal angle and genitohiatal distance.

CONCLUSIONS

In primary urodynamic stress incontinence, an increased resting genitohiatal distance or genitohiatal angle on sonographic imaging implies anterior vaginal wall prolapse. In addition, an increased genitohiatal distance is associated with functional impairment of urethral closure.

Reflexo pudendo-anal em mulheres normais

São descritas observações do registro do reflexo pudendo-anal em mulheres sem queixas de incontinência urinária. Foram estudadas 31 voluntárias adultas, com estimulação elétrica bilateral e independente do clitóris e registros de superfície em ambos os lados do músculo esfíncter externo do ânus (EEA). As respostas foram obtidas com pulsos duplos de 0,2 ms de duração e intervalos de 5 ms, aplicados a uma freqüência menor que 0,5 Hz. Foram medidas as latências iniciais das respostas. Não foram evidenciadas diferenças entre as respostas obtidas de cada lado do EEA e nem entre os lados, com relação aos estímulos. Uma das voluntárias não apresentou respostas após estimulação de um dos lados. Não foram observadas diferenças relacionadas a paridade total e nem com a presença de partos vaginais. A idade e o índice de massa corpórea não se correlacionaram com as respostas. Em 12% das respostas, a medida das latências foi dificultada pela baixa relação sinal-ruído.

Female Pelvic Floor Health

An often neglected but important area of women's health involves the pelvic floor. Pelvic floor health can be reviewed by examining phases of a woman's life. Because pelvic floor health is not readily discussed and few professionals are considered experts in this area, it is often overlooked in women's healthcare. In medicine, care of the pelvic area can become fragmented as it is divided among urologists, gynecologists, and colorectal surgeons. The specialty of urogynecology combines 2 of the areas, and some physical therapists and nurses choose to specialize in female pelvic floor health. The issues of pelvic floor health are often addressed only after symptoms have presented. However, healthy practices can enhance pelvic floor well-being and maintain quality of life as a woman ages. This article is a review of clinical, research, and editorial articles on female pelvic floor issues and a discussion of measures that can contribute to optimal pelvic floor health.

Innervation of the levator ani and coccygeus muscles of the female rat

In humans, the pelvic floor skeletal muscles support the viscera. Damage to innervation of these muscles during parturition may contribute to pelvic organ prolapse and urinary incontinence. Unfortunately, animal models that are suitable for studying parturition-induced pelvic floor neuropathy and its treatment are rare. The present study describes the intrapelvic skeletal muscles (i.e., the iliocaudalis, pubocaudalis, and coccygeus) and their innervation in the rat to assess its usefulness as a model for studies of pelvic floor nerve damage and repair. Dissection of rat intrapelvic skeletal muscles demonstrated a general similarity with human pelvic floor muscles. Innervation of the iliocaudalis and pubocaudalis muscles (which together constitute the levator ani muscles) was provided by a nerve (the "levator ani nerve") that entered the pelvic cavity alongside the pelvic nerve, and then branched and penetrated the ventromedial (i.e., intrapelvic) surface of these muscles. Innervation of the rat coccygeus muscle (the "coccygeal nerve") was derived from two adjacent branches of the L6-S1 trunk that penetrated the muscle on its rostral edge. Acetylcholinesterase staining revealed a single motor endplate zone in each muscle, closely adjacent to the point of nerve penetration. Transection of the levator ani or coccygeal nerves (with a 2-week survival time) reduced muscle mass and myocyte diameter in the iliocaudalis and pubocaudalis or coccygeus muscles, respectively. The pudendal nerve did not innervate the intrapelvic skeletal muscles. We conclude that the intrapelvic skeletal muscles in the rat are similar to those described in our previous studies of humans and that they have a distinct innervation with no contribution from the pudendal nerve.

Pelvic floor dysfunction: a conceptual framework for collaborative patient-centred care

BACKGROUND

Pelvic floor dysfunction is a disorder predominantly affecting females. It is common and undermines the quality of lives of at least one-third of adult women and is a growing component of women's health care needs. Identifying and supporting these needs is a major public health issue with a strong psychosocial and economic basis. The importance of the interdependence of mechanical, neural, endocrine and environmental factors in the development of pelvic floor dysfunction is well recognized. There is a paucity of data investigating the true prevalence, incidence, specific risk factors, poor outcome of treatment and subsequent prevention strategies for women with multiple pelvic floor symptomatology.

AIM

The aim of this paper is to present a critical review of the literature on the mechanism, presentation and management of multiple symptomatology in pelvic floor dysfunction and to propose a conceptual framework by which to consider the impact and problems women with pelvic floor dysfunction face.

METHODS

A comprehensive although not exhaustive literature search was carried out using medical and nursing databases BIOMED (1966-2002) NESLI (1989-2002) and EMBASE (1980-2003) CINAHL (1982-2003) and Cochrane databases using the key words 'pelvic floor dysfunction', 'incontinence (urinary and faecal)', 'genital prolapse', sexual dysfunction, 'aetiology', epidemiology' and 'treatment'. Retrospective and prospective studies and previous clinical reviews were considered for review. The articles retrieved were hand searched for further citations and referrals were made to relevant textbooks. Particular attention was paid to papers that focused on multiple pelvic floor symptoms.

FINDINGS

Pelvic floor dysfunction affects women of all ages and is associated with functional problems of the pelvic floor. Pelvic floor dysfunction describes a wide range of clinical problems that rarely occur in isolation. Inaccurate knowledge, myths and misconceptions of the incidence, cause and treatment of pelvic floor dysfunction abound. Given the significance of the aetiological contribution of factors such as pregnancy and obstetric trauma, ageing, hormonal status, hysterectomy and lifestyle in the development of pelvic floor disorders, the assessment, management and prevention of pelvic floor dysfunction remains a neglected part of many health care professionals educational preparation. This not only has major economic but also psychosocial implications for women, the general population and women's health care providers. A conceptual framework is also discussed that considers not only the impact and difficulties women with pelvic floor dysfunction face but also areas in which health care professionals can improve assessment and eventual treatment outcomes.

CONCLUSION

This paper demonstrates gaps in the current provision of women's health care services. Functional pelvic floor problems are perceived to have low priority compared with other health disorders, and treatment remains sub-optimal. Inherent in achieving and promoting better health care services for women is the need for better collaborative approaches to care. There is a need to identify and develop comprehensive interdisciplinary, multi-professional strategies that improve the assessment and treatment of pelvic floor dysfunction in primary, secondary and tertiary settings. If this area of women's health care is to be improved nurses, whether community- or hospital-based, must play a front-line role in challenging and changing current practices. Education needs to be given greater priority and the development of a specialist pelvic floor nurse role explored. Such strategies could substantially influence a more effective approach to women's health care needs, result in improved treatment outcomes and liberate women from the embarrassment, social and sexual isolation, restriction to employment and leisure opportunities and potential loss of independence that multiple symptomatology can generate.

Innervation of the levator ani muscles in the female squirrel monkey

OBJECTIVE

The purpose of this study was to characterize the innervation of the levator ani muscles in the female squirrel monkey and to investigate its usefulness as an animal model of pelvic organ prolapse.

STUDY DESIGN

Eleven nulliparous female squirrel monkeys with no pelvic organ prolapse were used in this study. Detailed pelvic dissections were conducted (n = 3), and the Koelle stain for acetylcholinesterase was used to identify the motor endplate zone in the levator ani muscles (n = 2). Unilateral levator ani (n = 4) and pudendal (n = 2) neurectomies were performed; changes in levator ani muscle mass and myocyte diameter were examined 14 days after neurectomy. Nerve biopsy specimens from each animal were processed for microscopy.

RESULTS

The levator ani nerve originated from the S2 spinal root and entered the pelvic cavity adjacent to the pelvic nerve between the flexor caudalis brevis and iliocaudalis muscles. The levator ani nerve then projected caudally and bifurcated to penetrate the iliocaudalis and pubocaudalis. A single motor endplate zone in each muscle correlated with the point of levator ani nerve penetration. The pudendal nerve originated from the S1-S2 spinal roots to innervate the urethral and anal sphincters, clitoris, and perineum, but not the iliocaudalis or pubocaudalis. Significant atrophy and myocyte shrinkage occurred in the iliocaudalis and pubocaudalis ipsilateral to the levator ani nerve transection (P <.05). Pudendal neurectomy produced no levator ani muscle changes.

CONCLUSION

Intrapelvic skeletal muscles in the female squirrel monkey are similar to humans and have distinct innervation with no contribution from the pudendal nerve. The squirrel monkey is likely to be a useful model of pelvic organ prolapse and warrants further study.

Three-dimensional magnetic resonance imaging assessment of levator ani morphologic features in different grades of prolapse

OBJECTIVE

The study was undertaken to identify the morphologic changes in the levator ani in different grades of prolapse by using reconstructed three-dimensional models of magnetic resonance images (MRI) and to subclassify prolapse into different categories on the basis of their levator ani morphologic characteristics.

STUDY DESIGN

Sixty-one women were studied, 8 women in stage I, 15 women in stage II, 22 women in stage III, 7 women in stage IV prolapse, and 9 asymptomatic volunteers with stage 0 prolapse. Axial, sagittal, and coronal T2-weighted pelvic magnetic resonance scans were obtained with the patient in the supine position. The three-dimensional models were reconstructed from the source images by using manual segmentation and surface modeling. The morphologic characteristics of the puborectalis were assessed on these reconstructed models by measuring (1). the levator symphysis gap, (2). the width of the levator hiatus, and (3). the length of the levator hiatus. To assess the iliococcygeus, we measured (1). the maximum width of the iliococcygeus, (2). the direction of its fibers that was assessed by measuring the iliococcygeal angle, and (3) the levator plate angle. Nine nulliparous asymptomatic women were studied as controls.

RESULTS

Alterations in levator ani morphologic features are not dependent on the grade of the prolapse, and not all women with pelvic floor prolapse have abnormal morphologic features. In healthy control subjects, the iliococcygeal width measured less than 40 mm and the iliococcygeal angle measured less than 20 degrees. On the basis of the MRI findings, four patterns of changes in the levator ani have been identified. Both the levator symphysis gap and the levator hiatus, which is dependent on the puborectalis function, widen with increasing grade of prolapse.

CONCLUSION

It is possible to subclassify prolapse on the basis of morphologic changes in the levator ani by using MRI. This may be a very useful predictor as to which patients have recurrent prolapse develop after surgery.

Innervation of the female levator ani muscles

OBJECTIVE

The objective of this study was to characterize the innervation of the human female levator ani muscles.

STUDY DESIGN

Detailed dissections of the peripheral innervation of the iliococcygeal, pubococcygeal, puborectal, and coccygeal muscles were performed in 12 fresh-frozen female cadavers (aged, 32-100 years) with the use of transabdominal, gluteal, and perineal approaches. Both the pudendal nerve and the sacral nerve roots that enter the pelvis from the cephalic side were followed from their origin at the sacral foramina to their termination. Pelvic floor innervation was described with reference to fixed bony landmarks, particularly the coccyx, the ischial spine and the inferior pubis. Photographs were taken, and nerve biopsies were performed to confirm the gross findings histologically. Biopsy specimens were stained with Masson's trichrome.

RESULTS

In each dissection, a nerve originated from the S3 to S5 foramina (S4 alone, 30%; from S3 and S4, 40%; from S4 and S5, 30%), crossed the superior surface of the coccygeal muscle (3.0 +/- 1.4 cm medial to the ischial spine [range, 1.0-4.2 cm]), traveled on the superior surface of the iliococcygeal muscle innervating it at its approximate midpoint, and continued on to innervate both the pubococcygeal and puborectal muscles at their approximate midpoint. The pudendal nerve originated from the S2 to S4 foramina, exited the pelvis through the greater sciatic foramen, traversed Alcock's canal, and branched to innervate the external anal sphincter, the external urethral sphincter, the perineal musculature, the clitoris, and the skin. Despite specific attempts to locate pudendal branches to the levator ani, none could be demonstrated. Nerve biopsy specimens that were obtained at gross dissection were confirmed histologically.

CONCLUSION

Gross dissections suggest that the female levator ani muscle is not innervated by the pudendal nerve but rather by innervation that originates the sacral nerve roots (S3-S5) that travels on the superior surface of the pelvic floor (levator ani nerve). Because definitive studies (eg, nerve transection or neurotracer studies) cannot be performed in humans, further studies that will use appropriate animal models are necessary to confirm and extend our findings.

Dynamic MR imaging of pelvic organ prolapse: spectrum of abnormalities

Pelvic organ prolapse is a relatively common condition in women that can have a significant impact on quality of life. Pelvic organ prolapse typically demonstrates multiple abnormalities and may involve the urethra, bladder, vaginal vault, rectum, and small bowel. Patients may present with pain, pressure, urinary and fecal incontinence, constipation, urinary retention, and defecatory dysfunction. Diagnosis is made primarily on the basis of findings at physical pelvic examination. Imaging is useful in patients in whom findings at physical examination are equivocal. Fluoroscopy, ultrasonography, and magnetic resonance (MR) imaging can be useful in evaluating pelvic organ prolapse. Advantages of MR imaging include lack of ionizing radiation, depiction of the soft tissues of the pelvic floor, and multiplanar imaging capability. Dynamic imaging is usually necessary to demonstrate pelvic organ prolapse, which may be obvious only when abdominal pressure is increased. Treatment is more likely to be successful if a survey of the entire pelvis is performed prior to therapy. Therapy is usually undertaken only in symptomatic patients. In all patients, imaging findings must be interpreted in conjunction with physical examination findings and the patient's symptoms.

Weakness of the pelvic floor: urological consequences

The pelvic floor comprises three compartments: anterior, posterior and middle. Weakness of the pelvic floor can lead to prolapse, urinary or faecal incontinence. This article deals with the defects in the anterior compartment which lead to urological consequences. The anatomy and management of stress incontinence are discussed.

Birth trauma and the pelvic floor: lessons from the developing world

Urinary incontinence, fecal incontinence, and pelvic organ prolapse are common stigmatizing conditions that afflict women far more often than they afflict men. It has been suggested that childbirth is the most likely factor to explain this great epidemiologic discrepancy between the sexes. Because the widespread availability of high-quality obstetric care through-out the industrialized world has led to precipitous drops in maternal mortality during the 20th century, many of the pathophysiologic mechanisms by which such injuries might arise are not as obvious as they were in times past. It is suggested that by looking at obstetric complications in the developing world, where the natural history of unrelieved obstructed labor is most obvious, it may be possible to shed new light on the pathophysiology of childbirth injury and its relationship to incontinence and prolapse. The spectrum of childbirth injuries resulting from obstructed labor in developing countries is surveyed, and the potential relevance of these findings to the more subtle forms of pelvic floor dysfunction seen in Western women is discussed.

Normal pelvic floor anatomy

The anatomy of the pelvic floor includes structures responsible for active and passive support of the urethrovesical junction, vagina, and anorectum. Intrinsic and extrinsic properties of the urethrovesical neck and anorectum allow maintenance of urinary and anal continence at rest and with activity. Damage to these structures may lead to loss of support and loss of normal function of the urethra, bladder, and anorectum. Over time, this damage can result in isolated or combined pelvic organ prolapse, urinary incontinence, and anal incontinence.

M. levator ani in the rat: does it really lift the anus?

BACKGROUND

There is a good deal of confusion about the denomination of the pelvic floor muscles of the rat in the literature. By carefully dissecting and observing tail and visceral movements and pressure measurements in the vagina, rectum, and urethra during electrical stimulation, we studied the anatomy and function of the different muscles and searched for similarities with the human anatomy.

RESULTS

We found some degree of similarity between the M. pubococcygeus and M. iliococcygeus muscles in both species. The M. levator ani in the rat resembles in gross anatomy the M. puborectalis in man, but the insertion and function are different. More specifically, stimulation of the M. levator ani led to only a negligible pressure rise in the rectum and no lifting of the rectum or anus.

CONCLUSIONS

The M. pubococcygeus and the M. iliococcygeus share similarities with their homologues in the human. The M. levator ani, which is present only in the male rat, reveals some anatomical resemblance with the human M. puborectalis but has a different insertion and function. Because it does not lift the anus during contraction, its denomination as M. levator ani seems unjustified. Because of its principal sexual function, its fixation to the bulbus, and its sensitivity to testosterone, naming this muscle M. bulbocavernosus dorsalis would indeed seem more logical.

Synthetic sling for genital prolapse in young women

OBJECTIVE

The aim is to repair uterine prolapse in young women, utilizing synthetic tape (Merselene). It is a prospective study demonstrating an operative procedure for correction of uterine prolapse in young women. This procedure was performed in three post-graduate teaching hospitals: Institute of Obstetrics and Gynaecology, Gandhi Hospital and Niloufer Hospital, Hyderabad, India.

METHOD

Through an abdominal approach, the Merselene tape was fixed on the posterior surface of the uterus and anchored to the anterior longitudinal ligament, over the sacral promontory. This procedure was performed on 19 women in the age group 17-27 years, two of whom were unmarried virgins.

RESULTS

The procedure rectified the descent of the uterus and kept it anteverted. In one of the cases, exploration at cesarean section showed that the sling was intact. There were no significant intraoperative or postoperative complications. Recurrence of prolapse was not reported in any of these cases.

CONCLUSION

This technique is a relatively simple method for correction of uterine prolapse in young women. The Merselene tape is inert, strong, flexible, effectively supports the uterus, and remains retroperitoneal.

Carbon dioxide laser for laparoscopic enterocele repair

The use of the carbon dioxide (CO2) laser for laparoscopic enterocele repair was evaluated in four women with an enterocele as the only pathology. Three women had a large enterocele after earlier hysterectomy, and one young woman had a congenital enterocele. The technique consists of vaporizing the peritoneum of the enterocele; however, it is important first to delineate carefully the lesion's circumference because of the strong retraction during vaporization. Subsequently, a posterior culdotomy is performed taking care to restore the horizontal position of the upper vaginal axis by shortening the uterosacral ligaments, which are sutured together on the midline and the posterior vaginal wall. The (CO2) laser has the advantage that the superficial vaporization it produces is rapid (<5 min), safe, and completely bloodless. The shrinking during vaporization facilitates subsequent repair. Postoperative morbidity and recovery were uneventful for all patients. The (CO2) laser seems to have some advantages over sharp endoscopic resection of enteroceles. The relative simplicity of technique and the low postoperative morbidity suggest that endoscopy could become routine in pelvic floor surgery, improving diagnosis and complementing vaginal surgery while avoiding laparotomy.