Posterior pubo-urethral ligaments in normal and genuine stress incontinent women

Role of puboperinealis and rectourethralis muscles as a urethral support system to maintain urinary continence after robot-assisted radical prostatectomy

The present study investigated the role of a urethral support system to maintain urinary continence after robot-assisted radical prostatectomy (RARP), with a focus on pelvic floor muscles, such as the puboperinealis muscle (PPM) and rectourethralis muscle (RUM). Finally, 323 patients who underwent RARP were analyzed in this study. All patients performed a one-hour pad test 1, 3, 6, 9, and 12 months after RARP to assess urinary incontinence and MRI before and 9 months after RARP to evaluate the pelvic anatomical structure. The preoperative cross-sectional area of PPM (2.21 ± 0.69 cm2) was significantly reduced by 19% after RARP (1.79 ± 0.60 cm2; p < 0.01). Positive correlations were observed between the amount of urinary leakage according to the 1-h pad test 1, 3, 6, 9, and 12 months after RARP and the change in the cross-sectional area of PPM by RARP (p < 0.01, < 0.001, < 0.001, < 0.001, and < 0.001, respectively). A positive correlation was also noted between the amount of urinary leakage 6 and 12 months after RARP and the preoperative RUM diameter (p < 0.05). The amount of urinary leakage 1, 3, 6, 9, and 12 months after RARP negatively correlated with the change in the antero-posterior diameter of the membranous urethra (MU diameter) from the static to dynamic phases during the Valsalva maneuver by cine MRI. Furthermore, the change in the MU diameter negatively correlated with the change in the cross-sectional area of PPM (p < 0.05). PPM and RUM play significant roles as a supportive mechanism to maintain urinary continence by functioning as a urethral support.

The new etiology and surgical therapy of stress urinary incontinence in women

OBJECTIVES

To determine the subjective and objective cure rate of a urethral stabilization procedure (USP) for stress urinary incontinence (SUI) in women; to describe this new surgical intervention; to record its potential complications; to establish the SUI etiology.

STUDY DESIGN

The author conducted a prospective case series study in ambulatory settings and under local anesthesia. Thirty-four consecutive women with uncomplicated SUI subjected to USP, which was performed by reconstructing site-specific defects within the urethral stabilizing mechanism (USM) and using no surgical slings, meshes or absorbable sutures. The paravaginal defect(s) was repaired by transvaginal approach. The endopelvic fascia was sharply separated from the ventral perineal membrane (VPM) just above the anterior urethral meatus. The vestibular bulbs sharply dissected from VPM and advance upwards. The VPM defect(s) reconstructed and vestibular bulbs placed back to the original location. The access to the peri- and the para-urethral region was created by making a lateral vertical incision, aside from the lateral urethral meatus and defects were repaired. The suburethral transverse incision was made beneath the urethral meatus and the stratum-by-stratum surgical dissection conducted until the lateral vaginourethral ligament is visualized bilaterally. The defect(s) within the vaginourethral ligaments was surgically reconstructed, and the vaginal wall repaired. The primary outcome measured subjective and objective cure rates, and the secondary outcome measured the occurrence of potential complications. The five-year postoperative follow-up was conducted.

RESULTS

Two out of thirty-four patients dropped-out from the study. The USP performed without difficulties, and no severe complication observed. One-subject developed superficial wound separation (3.1 %) and one-subject (3.1 %) developed urinary urge incontinence at the 5-postoperative-year. At 60-month follow-up subjective and objective cure rates were a 92 % and an 88 % respectively.

CONCLUSIONS

The urethral stabilization procedure yields a high degree of subjective and objective cure rates without severe complications and is a well-tolerated operation by women. The urethral stabilization procedure is a simple, easy to implement, and reproducible method for uncomplicated stress urinary incontinence in women. Site-specific defects within the urethral stabilizing mechanism constitute the etiology of the stress urinary incontinence in women.

Anatomy and histology of the lower urinary tract

The function of the lower urinary tract is basically storage of urine in the bladder and the at-will periodic evacuation of the stored urine. Urinary incontinence is one of the most common lower urinary tract disorders in adults, but especially in the elderly female. The urethra, its sphincters, and the pelvic floor are key structures in the achievement of continence, but their basic anatomy is little known and, to some extent, still incompletely understood. Because questions with respect to continence arise from human morbidity, but are often investigated in rodent animal models, we present findings in human and rodent anatomy and histology. Differences between males and females in the role that the pelvic floor plays in the maintenance of continence are described. Furthermore, we briefly describe the embryologic origin of ureters, bladder, and urethra, because the developmental origin of structures such as the vesicoureteral junction, the bladder trigone, and the penile urethra are often invoked to explain (clinical) observations. As the human pelvic floor has acquired features in evolution that are typical for a species with bipedal movement, we also compare the pelvic floor of humans with that of rodents to better understand the rodent (or any other quadruped, for that matter) as an experimental model species. The general conclusion is that the "Bauplan" is well conserved, even though its common features are sometimes difficult to discern.

Intergender differences in histological architecture of the fascia pelvis parietalis: a cadaveric study

The fascia pelvis parietalis (FPP) or endopelvic fascia is a well-known structure, but few studies described the detailed histological architecture, including the composite fiber directions. We hypothesized a gender-specific fiber architecture corresponding to the functional demand. For the first step to examine this hypothesis, we investigated specimens from 27 adult cadavers (10 males and 17 females) and 11 midterm fetuses (five males and six females) using immunohistochemistry and aldehyde-fuchsin staining. The adult female FPP was a solid, thick monolayered structure that was reinforced by abundant elastic fibers running across the striated muscle fibers, but it contained little or no smooth muscles (SM). In contrast, the male FPP was multilayered with abundant SM. In midterm fetuses, SM originated from the inferior part of the bladder and extended inferiorly along the gender-specific courses. Thus, we found a clear intergender difference in FPP architecture. However, the functional significance remained unknown because the basic architecture was common between nulliparous and multiparous women. Rather than for meeting the likely mechanical demands of pregnancy and vaginal delivery, the intergender difference of the FPP seemed to result from differences in the amount and migration course of bladder-derived SM as well as in hormonal background.

Functional anatomy of the female lower urinary tract and pelvic floor

Stress continence depends upon three factors: proximal urethral support, vesical neck closure, and urethral contractility. The position of the vesical neck is not static but mobile and under voluntary control. Its support depends upon connections of the urethrovaginal endopelvic fascia to the medial aspect of the levator ani. In addition, these fasciae are attached to the arcus tendineus fasciae pelvis which supports the urethra during levator relaxation, and probably during stress. Levator contraction supports the proximal urethra and also pulls the vesical neck anteriorly against a band of endopelvic fascia which is suspended between the arcus tendinei, compressing it closed. Relaxation of the muscles allows the vesical neck to descend, and facilitates its opening. The connective tissue and smooth muscle of the trigonal ring encircles the vesical neck's lumen, and may contribute to closure of this area. The striated urogenital sphincter muscle can contract to assist in maintaining continence in continent women whose vesical neck is not competent. It has a circular sphincteric portion from 20 to 60% of urethral length. From 60 to 80% it has a considerable bulk of muscle which forms an arch at the perineal membrane that would compress the urethra from above.

Anatomy of the urethral supporting ligaments defined by dissection, histology, and MRI of female cadavers and MRI of healthy nulliparous women

OBJECTIVE

There has been no uniformity of opinion concerning the structures supporting the female urethra. Therefore, the aims of this prospective study were to define precisely the female urethral support structures at cadaveric anatomic dissection and histologic examination and to determine which of these structures can be detected on MRI of cadaveric specimens and of healthy volunteers.

SUBJECTS AND METHODS

Dissection of seven formalin-preserved cadavers (age at death, 25-50 years; no parity history available) was performed by a professor of anatomy to explore the anatomy of the urethral supporting ligaments and was followed by MRI of the cadaveric specimens with ligamentous markers in place and then by histologic analysis of the dissected ligaments. MRI of 17 healthy nulliparous women (age range, 20-35 years; mean age, 25.5 years) was then performed using T2-weighted, dual turbo spin-echo, balanced fast-field echo, and STIR sequences. A standardized grid system that allowed us to record structural observations on sequentially numbered axial MR images was used by a radiologist who then applied a 4-point grading scale to assess ligament visibility. Three authors--one radiologist, one anatomist, and one urologist--then compared the appearance of each ligament seen in a cadaveric specimen with its appearance on MR images of the same cadaver and on MR images of volunteers.

RESULTS

At cadaveric dissection we identified ventral and dorsal urethral ligaments. The ventral urethral ligaments included the pubourethral ligaments, which were found to consist of three separate components coursing anteroposterior from the bladder neck to the pubic bone; the periurethral ligament; and the paraurethral ligaments. Dorsal to the urethra, a slinglike ligament, which we believe should be named the "suburethral ligament," was identified. This ligament had a distinct plane of cleavage from the anterior vaginal wall. The MRI findings in the volunteers correlated with the MRI and gross anatomic findings in the cadavers. The proximal pubourethral, periurethral, paraurethral, and suburethral ligaments had visibility scores of 3 (moderately visible) or 4 (easily visible) on MRI in 47%, 65%, 47%, and 53% of volunteers, respectively.

CONCLUSION

Our results present evidence that may help resolve previous controversies regarding the MR appearance of the ventral urethral ligaments and that better define the course of the ligament dorsal to the urethra, the suburethral ligament. We hope that this detailed anatomic information about the structures involved in continence may lead eventually to improvements in the treatments for women with stress urinary incontinence.

What are the supportive structures of the female urethra?

AIMS

Female stress urinary incontinence is thought to result from impairment of the connective tissue "ligaments" of the urethra. Surgical repair of female incontinence mainly involves fixation of the urethra to the pubic bone or other surrounding structures. In the present anatomical-radiological study, the anatomy of the connective tissue structures around the female urethra was investigated to determine the anatomical structures that support the urethra and the rhabdosphincter.

MATERIALS AND METHODS

The topography of the anterior compartment of the female pelvis was studied in serial sections and one anatomical preparation of 30 female fetuses and of six adult females. The pelves of 29 female fetuses were processed according to plastination histology technique. The pelves of the six adult specimens were processed according to sheet plastination technique. In addition, the anatomical findings were compared with MR images of 41 adult female volunteers.

RESULTS

The ventro-lateral aspect of the urethra remains free of fixating ligaments throughout its pelvic course. Ventro-laterally the urethra is enclosed by the ventral parts of the levator ani, its fasciae and a ventral urethral connective tissue bridge connecting both sides. Dorsally, the urethra is intimately connected to the wall of the vagina.

CONCLUSIONS

The female urethra has no direct ligamentous fixation to the pubic bone. Urethral continence after pregnancy and childbirth may be explained by a widening of the hiatus of the levator ani or the anterior vaginal wall, resulting in overstretching of the ventral urethral connective tissue bridge or the disruption of the fixation between urethra and vagina.

Morphology of the suburethral pubocervical fascia in women with stress urinary incontinence: a comparison of histologic and MRI findings

To correlate MRI with histologic findings of the suburethral pubocervical fascia in women with urodynamic stress incontinence. Thirty-one women with urodynamically proven stress urinary incontinence without relevant prolapse underwent preoperative MRI. Tissue specimens obtained from the pubocervical fascia were examined immunohistochemically (types I and III collagen, smooth muscle actin) and the results compared with the MRI findings. MRI demonstrated an intact pubocervical fascia in 61.3% of the cases and a fascial defect in 38.7%. A fascial defect demonstrated by MRI was associated with a decrease in actin (P<0.09) and an increase in collagen III (P<0.01) compared to an intact fascia. In women with stress urinary incontinence, smooth muscle actin in the pubocervical fascia is decreased, changed in structure, and replaced by type III collagen. MRI allows evaluation of the pubocervical fascia and its morphologic changes.

Surgical anatomy of the puboprostatic complex with special reference to radical perineal prostatectomy

OBJECTIVE

To investigate the retropubic space and attachments of the prostate and urethra, with special reference to radical perineal prostatectomy.

MATERIALS AND METHODS

Anatomical relationships were assessed intraoperatively in 60 patients, and in five cadavers after preparing the dorsal vein complex with coloured latex. Cross-sections of the area of interest were evaluated by microscopy.

RESULTS

The puboprostatic (pubovesical) ligaments could be clearly distinguished from the median part of the puboprostatic complex continuous with the urethral suspensory mechanism. The dorsal vein complex is integrated into this fibromuscular attachment of the prostate and male urethra. During the perineal approach, dissection in this region follows the so-called avascular plane.

CONCLUSION

With this new insight into the anatomical relationships the nomenclature derived from radical retropubic prostatectomy could be mirrored. In radical perineal prostatectomy, both the urethral suspensory mechanism and the dorsal vein complex can be preserved.

Computerised morphometric study of the paraurethral tissue in young and elderly women

AIM

Changes in structural support of the urethra and bladder neck have been proposed to be among the most important factors in the pathogenesis of stress urinary incontinence. In this context, we histologically investigated the paraurethral area in continent women to quantify the relative distribution of connective tissue, smooth muscle, vessels, nerves, and striated muscle. Previously published literature gives only descriptive evaluations of the relative distribution of these tissue components.

METHODS

We used a computerised morphometric method, which allowed us to estimate the paraurethral tissue distribution in a more objective way. The material was obtained by dissection during autopsy in five premenopausal and five postmenopausal women.

RESULTS

Paraurethral tissue consisted of 56% connective tissue (SD, 5%), 30% smooth muscle (SD, 5%), 11% blood vessel (SD, 6%), 2% striated muscle (SD, 3%), and 1% nerves (SD, 1%). We also found that the distribution of different tissue components along the length of the urethra did not differ at a statistically significant level. Furthermore, there was a statistically significant difference in the amount of connective tissue and blood vessels in the postmenopausal women compared with the premenopausal women.

CONCLUSIONS

The present study shows that the paraurethral area is built of heterogeneous tissue with small changes in its composition along the course of urethra. Increase in connective tissue was found to be the dominating change in the process of ageing.

Physiology of female micturition

Micturition is a dynamic physiologic process consisting of alternating storage and expulsion phases and is accomplished by complex interactions among innervation, smooth muscle, connective tissue, urothelium and supportive structures. Although our current understanding of the anatomy and physiology of the lower urinary tract is far from complete, intensive research over the last decade has dramatically improved our appreciation of the neural, biomechanical, biochemical, and morphologic properties of the bladder and urethra, as well as the hormonal influences and unique pelvic and perineal anatomy of women. Continued research related to the physiology of female micturition promises to offer new insights into the complex bladder-urethral interactions and to provide a basis for developing better management strategies for a variety of voiding dysfunctions in women.

The pubourethral ligaments--an anatomical and histological study in the live patient

The aim of the study was to analyze the structure, relations and insertions of the pubourethral ligament in the living female. Thirty-five women, mean age 44 years, were studied. The intravaginal slingplasty (IVS) procedure, as performed via two paraurethral incisions, allowed immediate access to the structures in this area, the urethra, vaginal hammock, pubourethral ligaments and anterior portion of the pubococcygeus muscle. Histological biopsies were performed from the structures identified as ligaments. The pubourethral ligament descends like a fan from the lower part of the pubic bone. It consists of vaginal and urethral parts, joined together by thin fibrous threads, giving the appearance of a continuous sheet of amorphous connective tissue. Each part generally varies between 5 and 7 mm in width and 3-4 mm in thickness. The urethral part is approximately 2 cm long and inserts into the midpart of the urethra. The vaginal part is approximately 3-4 cm long. It inserts into the vaginal hammock posterolaterally, approximately 1 cm short of the bladder neck. Histologically the ligaments consist of smooth muscle, elastin, collagen, nerves and, blood vessels. The dissections confirm that the pubourethral ligaments are strong finite structures. Allowing for differences between cadavers and live patients, relationships and insertions are much as described by Robert Zacharin.

Surgery for genitourinary prolapse and stress incontinence: a randomized trial of posterior pubourethral ligament plication and Pereyra suspension

OBJECTIVE

Our purpose was to compare two antiincontinence procedures in patients with severe genitourinary prolapse and coexisting clinical or potential stress incontinence.

STUDY DESIGN

In addition to cystopexy, 109 patients with a urethrocystocele of grade 2 or more and a positive stress test result with prolapse reduction received posterior pubourethral ligament plication or Pereyra suspension.

RESULTS

Of 55 patients undergoing posterior pubourethral ligament plication, 15 were clinically and 40 potentially incontinent; the same figures were 21 and 33, respectively, among 54 patients undergoing the Pereyra procedure. Follow-up was for 3 to 9 years. Subjective (60% vs 71%, p = 0.72) and objective (27% vs 57%, p = 0.14) cure rates were not statistically different among patients who were clinically incontinent (posterior pubourethral ligament plication vs Pereyra suspension). Among potentially incontinent patients, subjective (85% vs 100%, p = 0.03) and objective (50% vs 76%, p = 0.04) continence rates were higher after the Pereyra procedure. Overall, the cotton swab test had negative results (maximum straining angle < or = 30 degrees) after successful surgery in 79% and 96%, respectively, of patients (p = 0.03). Four subjects (7%) underwent removal of one Pereyra suture because of urinary retention or suprapubic wound infection.

CONCLUSION

Cystopexy with Pereyra suspension is recommended, particularly for patients with prolapse and potential stress incontinence.

The puboprostatic ligament and the male urethral suspensory mechanism: an anatomic study

OBJECTIVES

To perform a detailed anatomic study of the puboprostatic ligament and male urethral suspensory mechanism with comparisons to homologous female anatomy.

METHODS

Anatomic dissections were performed on hemipelves of normal fresh male and female cadavers.

RESULTS

The puboprostatic ligament was not a discrete "band" of fascia that simply fixes the prostate to the public symphysis, but a pyramid-shaped structure that is part of a larger urethral suspensory mechanism that attaches the membraneous urethra to the pubic bone. As in the female, the male urethral suspensory mechanism was composed of three continuous structures: the anterior pubourethral ligament (suspensory ligament of the penis and fascial reflection of the perineal membrane), the intermediate pubourethral ligament (arcuate and transverse ligaments), and the posterior pubourethral ligament (the puboprostatic ligament). The attachments of the urethral suspensory mechanism bilaterally inserted along the lateral border of the urethra to form a sling of support from the pubic arch.

CONCLUSIONS

The male and female urethral suspensory mechanism are comparable. Understanding the relationship of the male urethral suspensory mechanism to the urethra, striated urethral sphincter, and dorsal vein may help in performing the apical dissection of the prostate during radical retropubic prostatectomy and in preserving urinary continence following radical pelvic surgery.

The value of the vaginal pack test in large cystoceles

To detect possible stress urinary incontinence associated with but masked by large cystoceles protruding through the vaginal orifice, a vaginal pack test was done in conjunction with video fluoro-urodynamic studies. Sixteen female patients with large cystoceles did not demonstrate stress urinary incontinence on clinical examination and were included in this study. Additionally, 10 healthy female volunteers underwent the same test to study the effect of a vaginal pack on urethral dynamics. The vaginal pack revealed the presence of stress urinary incontinence in 11 patients (69%): 3 (19%) with type II (vesicourethral hypermobility) and 8 (50%) with type III (internal sphincteric deficiency). After insertion of the vaginal pack, urodynamic studies showed that the closing proximal urethral pressure in patients with stress urinary incontinence was significantly lower than in continent patients (p < 0.05). No significant change in urethral pressures was noted in volunteer subjects after vaginal pack insertion. Fluoroscopy showed kinking of the posterior urethra and enlargement of the most dependent portion of the cystocele, that is the lower half of the hourglass image. Our study suggests that the mechanisms of continence in these patients are multifactorial, including urethral kinking, urethral compression and pressure dissipation. The vaginal pack test is easy to perform, increases visualization of the vesicourethral unit when used with fluoroscopy, and can aid in the selection of patients who would benefit from anti-incontinence surgery and/or cystocele repair.

MRI of the female urethra and pelvic floor

— MRI is the most powerful imaging procedure to visualize the structures of the pelvic floor. We have been interested in the use of MRI towards a better understanding of the pathophysiology of genuine stress incontinence due either to anatomical malposition of the pelvic viscera or to an intrinsically damaged urethra. Axial continuous images were obtained with T2 weighted spin-echo sequence in a total of 47 patients. In stress incontinent patients the urethra was usually more distant from the pubic bone than in normal controls. The urethro-pelvic ligaments were seen to extend downward in an oblique course. The levator sling was frequently deficient, usually thin or partially replaced by fat and connective tissue. In our experience, MRI provides information about the quality of the urethral wall and the pelvic floor. It is clearly superior to other radiological methods and will likely assume an even greater role in evaluating the urethra with paraurethral area and the female pelvis.

Histological changes in the vaginal connective tissue of patients with and without uterine prolapse

The histological structure of the vaginal fascia was studied in two groups of patients: 10 consecutive women having a vaginal repair for uterine prolapse or descent and 10 consecutive women having an abdominal hysterectomy for fibroids. Abnormal histological changes were found in 7 out of 10 patients with uterine descent as compared to 2 out of 10 controls (P less than 0.05). This suggests a correlation between histological changes in vaginal connective tissue and pelvic laxity.