Biomechanics of Urinary Stress Incontinence Surgery – Theory of the Non-Permanently Acting Suburethral Supportive Structure

This biochemical study of the lower urinary tract as it relates to urinary continence and incontinence is based on the morphotopographic results of radiological, autopsy and surgical investigations in the period 1966–1968. The process of urinary continence is simply explained by the application of universal hydromechanical laws, which demonstrated that continence during straining results from compression of the urethra over a suburethral resistant structure. Compression occurs during dorsocaudal physiologic displacement of the urethrovesical complex in conditions of increased intra-abdominal pressure. The theory of a non-permanently acting suburethral support is based on these results and represents the essential principle of urinary stress incontinence surgery, namely, that surgery should create a suburethral resistance over which the proximal urethra is compressed during increased intra-abdominal pressure.  Such suburethral resistance may be created via the vaginal or the abdominal routes, using autogenous or heterogeneous tissue. A critical analysis of different surgical techniques and how they achieve the demands of this theory is presented. In this context two orginal surgical procedures incorporating the best biomechanical features are elaborated: slinglike colposuspension via the abdominal route, and suburethral duplication of the anterior vaginal wall by the vaginal route. The aim of this paper is to present the biomechanical study of urethrovesical phenomena playing a role in urinary continence and the pathogenesis and surgery of stress incontinence in light of our theory. Our personal experience with 1836 surgical procedures between 1968 and the end of 1997, encompassing 1056 slinglike colposuspensions and 780 suburethral duplications of the vagina, gives practical support to our concepts.     

Vaginal prolapse affecting bladder function

When pelvic reconstructive surgery is being considered, it is important that the presence of cystocele be carefully and accurately assessed preoperatively and intraoperatively so that appropriate correction can be achieved. Continence is under the influence of urethral tone and the response of the proximal urethra to changes in intra-abdominal pressure. Cranial elevation of a rotated vesicourethral junction to a normal retropubic position should be provided. Any surgical technique that alters the normal axis of the vagina should be accompanied by simultaneous obliteration of the cul-de-sac of Douglas to lessen the chance of postoperative enterocele and subsequent eversion of the vault of the vagina. When massive vaginal eversion causes displacement of the vesicourethral junction, a restoration of vaginal depth and axis by posthysterectomy transvaginal sacrospinous colpopexy with appropriate colporrhaphy will relocate a defective urethrovesical site to a higher and retropubic level within the pelvis, where the proximal urethra may once again be responsive to changes in intra-abdominal pressure.     

Urogynecologic Ultrasound is a Useful Aid in the Assessment of Female Stress Urinary Incontinence – A Prospective Study with TVT Procedure

The aims of the study were to study the suitability of certain urogynecologic ultrasound parameters, e.g. descent of the urethrovesical (UV) junction on Valsalva, posterior urethrovesical (PUV) angle both at rest and on Valsalva, and funneling of the vesical neck, in the pre- and postoperative assessment of stress urinary incontinence (SUI) and to evaluate the efficacy and safety of tension-free vaginal tape (TVT) for the surgical treatment of SUI. Forty-six consecutive women (mean age 61 years) with symptoms of SUI underwent TVT placement. The patients were examined prior to and on average of 11 weeks after the operation with perineal ultrasound. An upright coughing test on standing was performed every time. Operative success rate was 94% in this series. Urogynecologic perineal ultrasound examination seemed strongly to support an anamnestic diagnosis of genuine SUI, and TVT proved to be a safe and effective ambulatory procedure for the surgical treatment of SUI.     

New and simplified vaginal approach for correction of urinary stress incontinence in women

Twenty-lour patients with urodynamically confirmed urinary stress incontinence were operated upon with a new and simplified vaginal approach. This new technique is a simplification of a previously described transahdominal surgical method, in which a two-component fibrin sealant (Tissel^R) was used. The sealant resulted in an excess of fibrin, which induced fibrosis. securing the urethrovesical junction in an elevated position to the retropubic periosteum. In the present study, the sealant was deposited retropubically with a specially designed needle through the anterior vaginal wall. A great advantage with this procedure is that only local anesthesia is used and the patient can leave the outpatient clinic I hour after the operation The minimum duration of the follow-up period was 18 months The success rate was as high as 6.3%, and no side effects were observed. © 1995 Wiley-Liss, Inc.     

A Retrospective Comparison of Abdominal Sacrocolpopexy with Burch Colposuspension versus Sacrospinous Fixation with Transvaginal Needle Suspension for the Management of Vaginal Vault Prolapse and Coexisting Stress Incontinence

The objective of this study was to compare the surgical outcome of abdominal sacrocolpopexy and Burch colposuspension with sacrospinous fixation and transvaginal needle suspension in the management of vaginal vault prolapse and coexisting stress incontinence. One hundred and seventeen women with vaginal vault prolapse and coexisting stress incontinence were surgically managed over a 7-year period. The first 61 consecutive women who underwent sacrospinous fixation and transvaginal needle suspension comprised the vaginal group, and the following 56 consecutive women who underwent abdominal sacrocolpopexy and Burch colposuspension comprised the abdominal group. Office records were reviewed to assess the presence of recurrent prolapse and urinary incontinence during postoperative follow-up. Objective follow-up was available for 101 women. Mean duration of follow-up was 24.0 ± 15 months for the vaginal group, and 23.1 ± 12.6 months for the abdominal group. The incidence of recurrent prolapse to or beyond the hymen (33% vs. 19%, P = 0.0505) and lower urinary tract symptoms (26% vs. 13%, P = 0.0506) were significantly higher in the vaginal group than in the abdominal group. Our data suggest that the combined abdominal approach has a lower incidence of recurrent prolapse and lower urinary tract symptoms than the combined vaginal approach in managing vaginal vault prolapse and coexisting stress incontinence.     

The Influence of Bladder Volume on the Position and Mobility of the Urethrovesical Junction

The influence of bladder volume on the position, mobility and funneling of the bladder neck and proximal urethra was determined by transperineal ultrasound in a prospective comparative clinical study at Dunedin Hospital, Dunedin, New Zealand. One hundred and nine women underwent urodynamic assessment, either as part of the investigation of urinary incontinence or as follow-up after incontinence-correcting surgery. Bladder neck descent, retrovesical angle, rotation of the proximal urethra, and simple and extensive funneling/opening of the proximal urethra on Valsalva maneuver were assessed using ultrasound imaging at approximately 50 ml bladder volume and maximum bladder capacity (mean 355 ml, range 125–470 ml). The position of the bladder neck at rest was slightly higher at 50 ml than at maximum capacity (50 ml: 2.6 ± 0.4 cm, max. cap. 2.5 ± 0.4 cm; P=0.003) and it descended further with the Valsalva maneuver (50 ml: 1.9 ± 1.2 cm, max. cap. 1.7 ± 1 cm; P=0.004). There was also a higher degree of urethral rotation (50 ml: 41 ± 30°, max. cap. 39 ± 20°) with an empty bladder (P=0.072). As regards funneling of the bladder neck on Valsalva, equivalent results were obtained for 90 patients. In 19 cases there were discrepancies (Cohen’s κ 0.64). For extensive funneling to the midurethra the respective numbers were 83 and 26 (κ 0.41). Generally simple and extensive funneling was more frequently seen with a full rather than an empty bladder, simple funneling being diagnosed in an additional 14 cases (P= 0.06) and extensive funneling in an additional 19 (P=0.03). It was concluded that bladder filling influences the position and mobility of the bladder neck and the proximal urethra, which are both more mobile when the bladder is nearly empty. Funneling of the proximal urethra, however, is more easily observed with a full bladder. Imaging of the lower urinary tract should be undertaken at defined bladder volumes.     

Mechanism of Postoperative Urinary Continence

Stress incontinence used to be attributed mostly to urethral hypermobility, and consequently most surgical techniques focused on the region of the bladder neck and proximal urethra. This article reviews our knowledge about the mechanism of postoperative urinary continence based on anatomic, imaging and urodynamic studies. Reduction of urethral mobility, as measured by cotton swab testing or imaging studies, is not the only reason why continence surgery succeeds. Imaging techniques are of limited value for elucidating the continence mechanism because radiologic landmarks and criteria are not reproducible. Urodynamically, the increased pressure transmission after successful continence surgery is attributed to the retropubic repositioning of the urethra, its compression against the anterior vaginal wall, and improved transmission of intra-abdominal pressure during stress. The role of the ‘functional’ urethral obstruction remains to be studied. In incontinent patients with hypermobility of the bladder neck and proximal urethra continence can be achieved by surgical correction. However, stress incontinence is possible in the absence of urethral hypermobility, and standard surgical techniques can fail to restore continence in these patients.     

Percutaneous Bone Anchor Sling Using Synthetic Mesh Associated with Urethral Overcorrection and Erosion

Percutaneous bone anchor bladder neck suspension has been recommended as a less morbid alternative to traditional anti-incontinence procedures. Specifically, it has reported to be associated with shorter duration of hospitalization, catheterization and urinary retention, and equivalent short-term cure rates. Recently, there have been reports of pubic osteomyelitis associated with bone anchor placement, and high incidences of recurrent incontinence. To improve the effectiveness of the procedure the placement of a suburethral synthetic collagen-impregnated mesh without tension was recommended. A specific device is included with the kit (Suture Spacer (Microvasive/Boston Scientific Corp., Natick, MA)) to prevent overcorrection of the urethrovesical junction. We present a case of urethral erosion and complete urinary retention secondary to use of a percutaneous bone anchor sling using a ProteGen mesh (Microvasive/Boston Scientific Corp., Natick, MA). Significant postoperative urethral overcorrection was noted despite intraoperative use of the Suture Spacer.     

Laparoscopic Surgery for Genuine Stress Incontinence

Laparoscopic Burch colposuspension has rapidly become one of the primary surgical treatment options for genuine stress incontinence. The procedure has been modified by some investigators because of technical difficulty with laparoscopic suturing, but should be identical to the conventional open Burch procedure. This article reviews the indications, operative technique, clinical results, complications and learning curve for laparoscopic retropubic surgical procedures.     

Evaluation of Urethrovesical Angle by Ultrasound in Women with and without Urinary Stress Incontinence

Our aim was to investigate the role of ultrasonographic imaging in the evaluation of genuine stress incontinence (GSI). The posterior urethrovesical angles (PUVA) of each of 50 incontinent (group I) and 50 control cases (group C) were measured by both transperineal and transvaginal ultrasonography (TP-USG, TV-USG). In group I the angles were 94.9 ± 10.9 at rest and 102.7 ± 16.1 by TP-USG (P<0.001), and 100.6 ± 11.1 at rest and 103.3 ± 9.6 during Valsalva by TV-USG (not significant). In the control group these measurements were 93 ± 5.3, 96.2 ± 7.9 (P<0.001) and 98 ± 8.8, 101.1 ± 10.3 (P=0.001) by TV-USG, respectively. The degree of alteration of the angle, originating with Valsalva maneuver (D-PUVA) was 7.7 ± 11.8 in group I and 3.2 ± 4.95 in group C (P=0.014) by TP-USG, and 2.7 ± 11.8 and 3.2 ± 6.16 by TV-USG (NS). Our data reveal that PUVA and D-PUVA have important roles in GSI pathophysiology; however, ultrasonography, especially by the transvaginal route, cannot be a reliable useful method as a diagnostic tool in the evaluation of GSI.     

Colpovesical neck suspension for the correction of female stress urinary incontinence

A new surgical approach for the correction of female urinary stress incontinence has been devised. The retropubic space is entered through a dome-shaped incision in the vaginal vestibule. The bulbocavernosus muscles are separated from the urethra and the layers of the genitourinary diaphragm are opened beginning behind the symphysis pubis. The retropubic cavity is exposed and the junction of the vesical neck and vagina is identified. Double helical bites with 2-zero polypropylene sutures are taken from each side of the junction. The 2 ends of the sutures are brought ventrally with a suture carrier through a small incision just above the symphysis pubis in the midline and tied. This procedure moves the bladder neck forward and upward to the desired level by observing movement of the bladder neck through the vestibule. Of 20 patients treated 17 are fully continent and 3 remain much improved after 2 years.     

In situ anterior vaginal wall sling formation with preservation of the endopelvic fascia for treatment of stress urinary incontinence

The indications for sling procedures have evolved and encompass patients with either intrinsic sphincteric deficiency (ISD), anatomic incontinence or both. We have refined a technique that can be performed in a minimally invasive fashion with low attendant morbidity to provide a reproducible method of sling formation. Twenty patients with stress urinary incontinence underwent the in situ sling (ISS) with bone fixation. Subsequent evaluation at 24–29 months (mean =26.2 months) revealed that 95% of patients were cured. No recurrent cystoceles, paravaginal defects or significant detrusor instability have been noted. Urinary retention appeared transiently in only 3 patients and resolved in under 3 weeks. We feel the in situ sling with bone fixation provides a safe and effective means of management for stress urinary incontinence. Furthermore, the reduced surgical dissection may minimize the incidence of postoperative ISD and recurrent paravaginal defects that may accompany more traditional needle suspension procedures.Editorial Comment: The authors present an interesting approach to the performance of a suburethral sling procedure which utilizes the anterior vaginal mucosa beneath the urethra as the supportive section of the sling, similar to the Raz vaginal wall sling technique. The patch is secured with sutures which are transported to the suprapubic site and attached to the symphysis pubis with bone anchors. Whether this procedure will provide longterm support to the urethrovesical junction will only be judged with time, and with prospective studies with pre-and postoperative objective urodynamic evaluation. The present study is truly an initial report of the technique, performed on a small group of patients with genuine stress incontinence or intrinsic sphincter deficiency with or without urethrovesical junction hypermobility. One major concern with any technique utilizing bone anchors attached to sutures coming from the perivaginal tissue following dissection of the anterior vaginal compartment is the potential risk of introducing pathogens to the bone, with resultant osteitis pubis or osteomyelitis.     

Colpocystourethropexy: the way we do it.

In pure stress urinary incontinence the sphincteric mechanism is intact. Restoration of normal position and support to the vesicourethral segment usually re-establish normal sphincteric function. A suprapublic approach is used to gain adequate mobilization of the anteriorr vaginal wall and vesicourethral segment. Full thickness sutures applied in the anterior vaginal wall as far lateral from the urethra as possible are then tied to Cooper's ligament. Forward and upward lifting of the vesicourethral segment is achieved but the urethra is free in a wide retropubic space. Normal position with limited mobility of the sphincteric segment is attained, yet compression or obstruction of the urethra and surgical trauma to the delicate sphincteric musculature are avoided. Adsorbable sutures are used. Permanent fixation is to be achieved by the postoperative fibrosis made possible after all retropubic fat has been cleared away. This technique has been uniformly successful in virginal cases and in the great majority of the least favorable cases, after repeated failures. Adequate mobilization proper placement of sutures and prevention of compression and surgical damage are the keys to longlasting successful repair.     

Vaginal Nylon Sling: Loop Length and Surgical Outcomes in those with Urethral Hypermobility and Intrinsic Sphincter Deficiency

Fifty-four women with stress incontinence underwent a vaginal nylon sling procedure. Of these, 15 were diagnosed as having type I, 27 as type II, and 12 as type III genuine stress incontinence. Follow-up averaged 25 months (range 6–42). The total suture length prior to ligation, which supports the bladder neck with no tension, varied from 200 to 313 mm and demonstrated weak correlation with body mass index (R²= 0.076, P = 0.043) and body weight (R²= 0.082, P = 0.036). The objective success rate was 89% (48 of 54 patients) 25 months later; the subjective rate was 93% (50 of 54 patients). Kaplan–Meier analysis demonstrated that the cumulative continence rate was 85.6% at 42 months for those with type I, 88.4% at 42 months for those with type II, and 91.7% at 40 months for those with type III incontinence (P>0.05). The main postoperative complication was retention or difficulty in urination. It was concluded that the total suture length cannot be determined in relation to patient’s physical parameters, but rather on surgical experience, and that this operation is recommended to those with not only intrinsic sphincter deficiency but also with urethral hypermobility, provided surgery is executed with safe precautions.     

Anterior bladder tube flap reconstruction of the urethrovesical neck after radical retropubic prostatectomy.

Difficulty with urethrovesical neck anastomosis after radical retropubic prostatectomy led us to form an anterior bladder tube flap for anastomosis to the transected urethra in 5 selected cases. We found that combining the anterior bladder tube flap technique with radical retropubic prostatectomy facilitates the urethrovesical neck anastomosis and improves the transient postoperative incontinence sometimes encountered. Results of the 5 patients in whom this technique was used form the basis for a brief discussion of the technique.     

Vaginal Configuration on MRI after Abdominal Sacrocolpopexy and Sacrospinous Ligament Suspension

An MRI study was conducted to compare the vaginal configuration of women who had undergone sacrospinous fixation with transvaginal needle suspension or abdominal sacrocolpopexy with retropubic colposuspension with that of normal controls. MRI examination demonstrated that in normal controls the lower vagina formed an acute angle (mean 53°) with the pubococcygeal line and intersected the upper vagina at a mean angle of 145°. In the abdominal repair group the lower vagina intersected the pubococcygeal line at a mean angle of 57° and joined the upper segment at a mean angle of 137°. In the vaginal repair group the lower vagina intersected the pubococcygeal line at a mean angle of 54° and joined the upper segment at a mean angle of 220°. Our study demonstrated that abdominal sacrocolpopexy with retropubic colposuspension more closely restored the vagina to its normal configuration, whereas sacrospinous fixation with transvaginal needle suspension creates an abnormal vaginal axis.     

Effects of Gender and Age on the Association of Apolipoprotein E ε4 with Bone Mineral Density,Bone Turnover and the Risk of Fractures in Older People*

The aim of this study was to examine whether the presence of apolipoprotein E ε4 (ApoE ε4) is associated with a lower bone mineral density (BMD), lower quantitative ultrasound (QUS) measurements, higher bone turnover and fracture risk, and whether these relations are modified by gender and age. A total of 1406 elderly men and women (≥65 years) of the Longitudinal Aging Study Amsterdam (LASA) participated in this study. In all participants, QUS measurements were assessed, as well as serum osteocalcin (OC) and urine deoxypyridinolin (DPD/Cr urine). Follow-up of fractures was done each three months. In a subsample (n = 604), total body bone mineral content (BMC) and BMD of the hip and lumbar spine were measured. In addition, prevalent vertebral deformities were identified on radiographs. In women, the presence of ApoE ε4 was associated with significantly lower femoral neck BMD (g/cm²; mean ± SEM; ε4+, 0.64 ± 0.01 vs. ε4−, 0.67 ± 0.01; p= 0.04), lower trochanter BMD (g/cm²; mean ± SEM; ε4+, 0.58 ± 0.01 vs. ε4–, 0.61 ± 0.01; p= 0.01) and lower total body BMC (g; mean ± SEM; ε4+, 1787 ± 40.0 vs. ε4–, 1863 ± 23.8; p= 0.04). Women with ApoE ε4 also had a higher risk of severe vertebral deformities (OR=2.78; 95%CI: 1.21–6.34). In men, the associations between ApoE status and both hip BMD and QUS depended on age. Only among the younger men (65–69 years) was the presence of ApoE ε4 associated with lower BMD values. Bone markers and fractures were not associated with ApoE ε4 in either women, or men. In conclusion, this large community-based study confirms the importance of ApoE ε4 as a possible genetic risk factor related to BMD and vertebral deformities and demonstrates that its effect is gender related, and depends on age in men only. Received: 6 July 2001 / Accepted: 2 April 2002     

Stress incontinence: a new endoscopic approach

We describe our experience in using a new endoscopic technique for suspending the bladder neck and urethra in 16 patients with stress incontinence. The procedure was started by dissecting the retropubic space, first with a sound and then with a Foley catheter before passing an absorbable suture from the abdominal fascia to the bladder neck using an elbowed needle introduced into the bladder through the neck and exteriorized through the urethra. The dissection of the retropubic space helped to form postoperative adherences which fixed the bladder neck and the urethra firmly to the pubic symphysis. The technique is simple, it does not require vaginal surgery, and the incidence of complications is minimal.     

Bone Mineral Density in Sixty Adult Patients with Marfan Syndrome

Sixty adult patients (40 women, 20 men) with Marfan syndrome (MFS) according to the Berlin criteria had a full clinical examination and bone mineral density (BMD) measurement by dual-energy X-ray absorptiometry of the hip and nondominant forearm. BMD was expressed as a Z-score and compared with the reference population of the Hologic database. In MFS men, BMD (g/cm²) was compared with the BMD of 45 normal tall Caucasian adults. Osteocalcin was measured by radioimmunoassay. In patients with MFS, BMD was compared between patients with and without previous fractures and according to the phenotypic severity of MFS. The mean age of the patients was 32.9 ± 9.3 years (women 32.5 ± 9.7, men 33.4 ± 8.6), mean height was 180.3 ± 10.3 cm (women 176.3 ± 9.2, men 188.1 ± 7.5) and mean body mass index 20.9 ± 3.6 kg/m² (women 20.8 ± 3.4, men 20.95 ± 3.97). Hyperlaxity score (Beighton criteria) was 6.9 ± 1.1. Six patients (10%) had a previous fracture. Thirty per cent of patients had had at least one previous operation for scoliosis, aortic dilatation or eye problems. BMD values in the 60 patients were as follows: Z-score of the hip, −1.26 ± 0.93, p<10⁻⁹ (neck, −0.93 ± 1.09, p<10⁻⁹; trochanter, −1.31 ± 0.85, p<10⁻⁹; intertrochanter, −1.39 ± 0.99, p<10⁻⁹; Ward’s triangle, −0.93 ± 1.88, p<10⁻⁹); Z-score of the radius: −1.6 ± 1.06, p<10⁻⁹ (1/3 proximal, −1.29 ± 1.03; mid-radius, −1.94 ± 1.04; ultradistal, −0.68 ± 1.1, p<10⁻⁹). The decrease in BMD was similar in men and women at both the hip and the radius. BMD in MFS patients was significantly decreased at cortical compared with trabecular sites (radius 1/3 proximal vs ultradistal, p<0.0001; total femur vs Ward’s triangle, p<0.0005). No difference in BMD was found between MFS patients with or without previous fractures and those with severe or less severe phenotypic expression of MFS. An influence of height and weight in MFS on BMD is suspected. Osteocalcin was not increased in our group of MFS patients. Thus both men and women with MFS have a significant deficit of BMD at the hip and radius. The decrease in BMD is present equally in both sexes and is more pronounced at predominantly cortical sites. In our group of patients we found no increase in fractures and no relation between decreased BMD and phenotypic expression of the syndrome. Received: 30 October 1998 / Accepted: 26 May 1999     

Quantitative Computed Tomography in the Evaluation of Spinal Osteoporosis Following Spinal Cord Injury

Disuse osteoporosis occurs in the lower extremities of patients with spinal cord injury (SCI). However, spinal osteoporosis is not usually observed in these patients. We investigated lumbar spine bone mineral density (BMD) in SCI patients using single energy quantitative computed tomography (QCT) and dual-energy X-ray absorptiometry (DXA). Our study population consisted of 64 patients with long-standing SCI. Spine BMD (g/cm³) was assessed by QCT at four vertebrae ranging from T11 to L4 with single midvertebral CT slices 1 cm thick parallel to the vertebral end-plates. Confounding variables affecting normal trabecular bone pattern, such as compression fractures, surgical hardware or fat replacement, were excluded. For a subset of 29 patients, DXA values of the spine and femoral neck were also measured, and QCT and DXA Z-scores were compared On the average, the 64 SCI patients had Z-scores 2.0 ± 1.2 below those of age-matched controls. In the subset of 29 patients with both QCT and DXA measurements, the QCT and DXA Z-scores were 2.4 ± 1.1 below and 1.3 ± 2.3 above the mean, respectively (p<0.0001). Our results indicate that QCT reveals osteoporosis of the spine after SCI, in contrast to DXA. We postulate that QCT is more valuable for evaluating spinal osteoporosis following SCI than DXA and thus recommend QCT for spinal BMD studies in SCI. Received: 20 December 1999 / Accepted: 17 April 2000