326 CHANGES IN THE EXTRACELLULAR MATRIX OF THE CARDINAL LIGAMENT ARE ASSOCIATED WITH UTERINE PROLAPSE IN POSTMENOPAUSAL WOMEN

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326

The LFG-Complex (Levator Ani Muscle – Fossa Ischioanalis – Gluteus Maximus Muscle) and its role for the functional integration of the Pelvic Floor

Changes in the extracellular matrix of the cardinal ligament are associated with uterine prolapse in postmenopausal women

Soljanik I.1, Janssen U.2, Lienemann A.3, Fritsch H.4, Weissenbacher E.R.5, Stief C.5

Soares L.C., Cabral C.A.P., Sampaio F.J.B., Cardoso L.E.M.

Ludwig-Maximilians-University, Urology, Munich, Germany, Technical University, Obstetrics and Gynecology, Munich, Germany, 3Ludwig-Maximilians-University, Clinical Radiology, Munich, Germany, 4University of Innsbruck, Anatomy, Innsbruck, Austria, 5Ludwig-Maximilians-University, Obstetrics and Gynecology, Munich, Germany

State University of Rio de Janeiro, Urogenital Research Unit, Rio de Janeiro, Brazil

1

2

Introduction & Objectives: The levator ani muscle (LAM) is the major structure of the pelvic floor (PF) and serves as primary support for the pelvic organs. Pelvic floor muscle (PFM) exercises are regularly used as an intervention in the conservative treatment of urinary stress incontinence. It has been emphasised that exercises of the PFM, especially the LAM, should be performed in isolation without contraction of the glutei muscles (GM). Contracting the GM during PFM-exercises is considered incorrect [1] as these actions may occur without concurrent PFM activity and thus render the exercises ineffective. The aim of this study was to assess the importance of the relationships between the LAM, fossa ischioanalis (FI) and the GM for the functional integration of the PF. Material & Methods: Using a PC-compatible surface electromyography (s-EMG) and a magnetic resonance imaging (MRI) 84 nulliparous female volunteers, aged 16 to 26, without a history of urinary and anal incontinence, genital prolapse, surgeries or injury of the PF were examined. The electromyogramms were recorded simultaneously vaginally of the LA and with two electrode pairs of the GM during active voluntary contraction of the PFM and at rest. Ten multimeasurements were done for each of the six body positions (BP), which were described by Bø et al. [2] as BP which support selective contraction of the LA. The functional MRI was performed with 1.5 Tesla superconductive magnet unit (Visionâ, Siemens, Germany) and included a dynamic midsagittal, parasagittal bilateral, axial (upper and lower rim of the pubic bone) True FISP sequence (TR 5.8 ms, TE 2.5 ms, matrix 224 x 256, field of view 236 x 270 mm, 20 measurements). During the examination the volunteer was asked to relax her PFM, contract them slowly to the maximum and then relax them again. Results: Representative selective LA contractions were not proved. Simultaneous contraction of the LA and the GM muscles in the s-EMG was observed independently of the BP (97,2%). Maximum contractions of both muscle groups were seen in those BP with knees bent and apart. The results of the MRI showed a synchronous movement of all structures: the LA, the FI and the GM. During contraction the LA area (- 7.8 %) was reduced, the GM area (+ 8.4 %) was increased significantly. The FI area remained unchanged. Analysing the sections we found out, that the network of connective tissue septa, which goes through the FI, connects the LA and the GM muscles. Conclusions: The LAM, the FI and the GM are connected morphologically and functionally. Therefore we recommend, these structures be considered as the ‘LFG-Complex’, emphasizing the importance of this unit for the functional integration of the PF. 1 Bump 1996 Am J Obstet Gynecol 175: 10-7 2 Bø 1994 In: Schuessler. Pelvic floor re-eduction: principles and practice. 134-9



327

The effect of intravesical Resiniferatoxin, Oxybutynin, and Lidocaine on the afferent autonomic Bladder Sensory Threshold in rat Daneshgari F., Yamada H., Liu G., Ukimura O.

Introduction & Objectives: Clinical efficacy of intravesical administration of Resiniferatoxin (RTX), Oxybutinin and Lidocaine have previously been reported. However, details regarding mechanisms of these pharmacological agents remain unknown. Recently we have developed a novel animal model that allows assessment of neuroselective bladder sensory function using Neurometer®, by measuring the bladder sensory threshold (BST). Objectives: To evaluate the afferent fiber-selective effect of intravesical RTX, Oxybutynin, and Lidocaine on sensory thresholds of the bladder in rats. Material & Methods: A total of 28 female Sprague-Dawley rats were used. We implanted a newly developed device in the bladder to assess electrical sensory threshold. The Neurometer® electrostimulator was used to apply sine-wave electrical stimulation at 250 Hz and 5 Hz (reported to be selective for A-delta and C-fibers, respectively) using to the bladder mucosa at increasing intensity until a startle or vocalization response was observed. The minimum intensity, at which that response was seen, was defined as the bladder sensory threshold (BST). Three days after implantation, RTX, Oxybutynin, Lidocaine or saline was instilled intravesically. Conscious BST measures were recorded prior to administration and at 1 and 24 hours post-instillation. Results: Intravesical administration of Oxybutynin or saline did not affect the BST values at either 250 or 5 Hz. A significant increase in BST was observed 24 hours post-instillation of RTX at a stimulus frequency of 5Hz (p=0.028). One hour post-instillation of Lidocaine, a significant increase in BST was observed at stimulus frequencies of 250 and 5 Hz (p=0.028, and p=0.028, respectively), however, 24 hours post-instillation BST returned to near baseline values. Table: BST values prior to, 1 hour after, and at 24 hours after intravesical administration Agent　

Frequency

Baseline BST

Saline (n=7)

250 Hz 5 Hz 250 Hz 5 Hz 250 Hz 5 Hz

26.8±4.7 14.4±3.4 32.7±7.0 13.8±4.9 29.6±5.4 12.6±4.5

Post-instillation BST 1 hour 28.4±4.4 14.8±2.4 30.0±7.9 14.9±5.6 32.1±11.5 12.5±4.1

24 hours 24.8±7.5 13.0±3.1 29.7±3.6 13.2±6.0 28.8±5.2 18.4±3.2 *

250 Hz 5 Hz

26.6±8.6 12.5±5.3

40.5±6.4 * 22.9±6.8 *

27.5±6.5 14.1±5.8

Resiniferatoxin (n=7) (1microM) Lidocaine (n=7) (4%Lidocaine solution)

Data are expressed as means ± standard deviations *, P<0.05, statistically significant difference from baseline values using Wilcoxon sign-rank test Conclusions: We were able to assess fiber-selective responses of bladder afferent pathways by measurement of bladder sensory threshold. Our animal model could be used for assessment of afferent bladder pathways in various pathological conditions, as well as for evaluating the effect of therapeutic agents on afferent bladder sensory function.

Eur Urol Suppl 2007;6(2):104

Material & Methods: Samples of the cardinal ligament were obtained during radical hysterectomy from the following groups of parous women: (1) 15 pre-menopausal, without UP (mean age 43.8±3.9 years); (2) 10 post-menopausal, without UP (mean age 63.5±12.0 years); and (3) 13 post-menopausal, with UP (mean age 66.5±10.4 years). After excision, ligament samples were freed from associated tissues, immediately fixed in acetone, delipidated in chloroform:methanol, and dried. Glycosaminoglycans (GAG) were isolated by papain digestion and precipitations in cetylpyridinium chloride and ethanol. Total GAG was estimated as hexuronic acid and expressed as µg hexuronic acid per milligram of dry tissue. Total collagen concentration was determined by a hydroxyproline assay and expressed as µg hydroxyproline per milligram of tissue. Results were statistically analyzed by one-way ANOVA followed by pairwise comparisons using the Bonferroni method. Results: Collagen concentration was increased by 64.9% in group 2 compared to group 1 (107.5±26.6 vs 65.2±12.0, p<0.004, respectively). In group 3, however, the concentration (60.9±14.0) was not significantly different from that of group 1. On the other hand, the concentration in group 3 was reduced by 43.4% in relation to group 2 (p<0.004). GAG concentrations determined thus far indicate that the contents in groups 1, 2 and 3 do not differ significantly (1.25±0.53, 1.56±0.14, 1.54±0.10, respectively). Conclusions: Aging increases collagen content of the cardinal ligament in women without UP. However, in post-menopausal women with UP, this remodeling does not occur and thus collagen concentration is substantially decreased compared to age-matched women without UP. A cardinal ligament with such a reduction in collagen should be comparatively less stiff and therefore could account for UP. Additionally, since estrogen may increase collagen expression in women (Patriarca MT et al. Eur J Obstet Gynecol Reprod Biol. 2006; Jun 22), hormonal factors may underly UP in post-menopausal women.



328

Single channel, multichannel and 3 dimensional water perfusion pressure profilometry in a bench model Hirst G.1, Beeton J.2, Guerrero K.3, Emery S.3, Lucas M.1

Morriston Hospital, Urology, Swansea, United Kingdom, 2Swansea Institute of Higher Education, Physiology, Swansea, United Kingdom, 3Singleton Hospital, Urogynaecology, Swansea, United Kingdom 1

Cleveland Clinic, Glickman Urological Institute, Cleveland, United States of America

Oxybutynin (n=7) (0.5mg/ml)

Introduction & Objectives: The cardinal (Mackenrodt) ligament is a major structure supporting the uterus and is thought to be involved in uterine prolapse (UP) and associated pelvic complications. Indeed, an altered expression of estrogen receptors has been shown to occur in cardinal ligaments from women with UP (Lang JH et al. Int J Gynaecol Obstet. 2003;80:35-39). The cardinal ligament is made up mostly of connective tissue and the concentration of its main components in cases of UP, however, are not known. Here we investigated the biochemical composition of the extracellular matrix of the cardinal ligament in women with and without UP.

Introduction & Objectives: The urethral sphincter is a complex three dimensional (3D) structure. Sphincteric dysfunction is an integral component in the development of stress urinary incontinence (SUI) but there is no test available which defines urethral function accurately. Single channel pressure profilometry (SCPP) has been used the most though it is only able to measure urethral pressure in one direction. Multichannel pressure profilometry (MCPP) was developed to assess sphincter function in the gastro-intestinal tract as it records pressure in several directions simultaneously. These may then be converted in to a 3D image using a computer program. However, there have been no studies to determine the reliability of this technique. The aims of this thesis were to assess the reliability of SCPP and MCPP in a bench model, then to perform MCPP in a predictable bench model to produce 3D images. Material & Methods: A bench model was developed and SCPP performed using the BrownWickham method using different combinations of withdrawal and perfusion rates. Repeatability was assessed by comparing five consecutive profiles, whilst reproducibility was assessed by performing another five profiles on the same model later the same day. Four different multichannel catheters were tested in a similar way. Finally, a model was constructed with an artificial urinary sphincter (AUS) in order to produce a 3D image in a predictable model. Profiles were compared visually and mathematically in terms of mean pressure, mean correlation and the difference between the maximum and minimum mean pressures for each set of five profiles, using predefined limits of acceptability. Results: For SCPP, a withdrawal rate of 0.5mm/sec and perfusion rate of 1ml/min gave the most repeatable and reproducible profiles. For MCPP, a 10F 6 channel catheter with a perfusion rate of 1ml/min and withdrawal rate of 1mm/sec produced the most repeatable and reproducible profiles, though they did not meet the predefined limits of acceptability because the differences between pressures recorded by each channel for consecutive profiles were not insignificant. Using the mean pressure of the five profiles for each channel, a 3D image was produced of the AUS to demonstrate the pressures imparted on the urethral wall by the AUS. Conclusions: This is the first in vitro bench study to address repeatability and reproducibility of MCPP. Excessive variations in pressure were seen in each channel between consecutive MCPP profiles. Whether these were true differences or artefactual requires further evaluation. Though it may have limited use in accurately determining urethral pressure in each direction, the pressures recorded may be reconstructed to produce a graphical 3D image of the resolution of forces acting on the urethral wall. These images may be of value in furthering our understanding of the pathophysiology of SUI and evaluating surgical treatments.