Female urethral syndrome: Clinical and urodynamic perspectives

Eighteen women with the urethral syndrome were studied urodynamically with synchronous video-pressure flow studies and electromyography of the external urethral sphincter (EUS). When compared with an age and sex matched control group, the most striking finding was a significantly higher than normal maximum urethral closure pressure. Abnormal and low urinary flow rates, instability of the intraurethral pressure at rest, incomplete funnelling of the bladder neck, and distal urethral narrowing during voiding constitute other typical urodynamic findings in the female urethral syndrome. Detrusor-striated sphincter dyssynergia or primary striated sphincter spasm was not observed. Even though striated E US spasticity cannot be excluded as a cause of this syndrome in some patients, an autonomically mediated spasm of the smooth muscle sphincter seems plausible to explain both our urodynamic findings and a favorable response of 4 patients treated with alpha-blocking agents.     

Urethral profilometry in women with uterovaginal prolapse

The aim of the study was to investigate the continence mechanism in women with uterovaginal prolapse by analysing urethral pressure profiles. Twenty-four women (mean age 59.0±11.9 years, mean parity 3.1±1.6) with prolapse underwent urodynamic evaluation. Urethral pressure profiles were obtained with prolapse and after reduction of the prolapse with a swab stick in the posterior vaginal fornix. After reduction the maximum urethral closure pressure (MUCP) and pressure transmission ratios (PTR) in all four quartiles of the urethra decreased, the position of the MUCP was shifted proximally and the functional urethral length was increased. Thirteen women reported a history of continence and 11 reported incontinence. Ten of 13 women (77%) who reported continence with prolapse were incontinent with their prolapse reduced. In these women, MUCP and PTRs in the first three quartiles of the urethra decreased significantly upon prolapse reduction. In the patients who reported incontinence with prolapse, only the MUCP decreased significantly upon prolapse reduction. Comparisons between the historically continent and incontinent women showed a statistically significant difference only for PTRs in the second and third quartiles of the urethra before prolapse reduction. Because the position of maximum urethral closure pressure before reduction was located in the distal half of the urethra in all patients, we conclude that direct pressure of the prolapsed mass on the urethra (rather than kinking) is the mechanism masking incompetence of the urethral closure mechanism in women with uterovaginal prolapse. The 77% rate of latent incontinence in this series suggests that women with severe pelvic relaxation should undergo careful urogynecologic evaluation before an attempt at surgical correction.Editorial Comment: Masked incontinence associated with genital prolapse is a well known problem for urogynecologists. The causes for this finding, e.g. kinking or compression, are not yet clear. The present study supports the compression theory. To gain a better understanding in the future, two points are important: to find a standard procedure for prolapse repositioning (pessary v speculum v swab stick) and to combine functional and radio- or sonomorphological findings in order to see whether compression and/or kinking occurs and with what consequences.     

Role of striated and smooth muscle components in the urethral pressure profile in traumatic neurogenic bladders: a neuropharmacological and urodynamic study. Preliminary report

Urodynamic investigations with urethral pressure profile, and vesical, intrarectal and anal pressure recordings were performed in 37 patients with spinal cord lesions. The recordings were done before and after phentolamine injections and/or pudendal nerve blocks to evaluate the respective contribution of sympathetic and somatic innervation to the maximum urethral closure pressure in the mid and distal portions of the membranous urethra. A pressure gradient was demonstrated in the membranous urethra with higher values in the distal than in the mid portion. These results emphasize that the interrupted withdrawal technique is superior to the continuous technique in patients with upper motor neuron bladders. Mid urethral striated and smooth muscle components were shown to represent approximately 60 and 30 per cent of the maximum urethral closure pressure, respectively. In the distal urethra striated and smooth components are more abundant than in the mid portion and contribute in equal proportion to the maximum urethral closure pressure. No substantial role was found for the vascular bed in the maximum urethral closure pressure. The greatest pressure decrease in the mid and distal urethra of patients with lower motor neuron bladders was believed to be an effect of denervation supersensitivity. The results of pudendal blocks showed sphincter dyssynergia to be mediated through pudendal nerves via spinal reflex arcs. Phentolamine effects on bladder activity suggest that blockade of alpha-adrenergic receptors inhibits primarily the transmission in vesical and/or pelvic parasympathetic ganglia and acts secondarily through direct depression of the vesical smooth muscle. Our neuropharmacological results raise strong doubts as to the existence of a sympathetic innervation of the striated urethral muscle in humans.     

Role of striated sphincter muscle in urethral closure under stress conditions: an experimental study

The three-component mechanism for urethral closure under stress conditions is composed of urethral tension, passive pressure transmission and reflex pressure transmission. The reflex pressure transmission is regarded as a global result of the striated muscles of the urethra and the pelvic floor. In this experimental study, the question of what peak the reflex pressure reaches and which parts of the striated sphincter muscles produce the reflex pressure transmission is examined. The urodynamic and operative experiment was carried out on 12 female German shepherd mutts, whereby the passive and the reflex pressure transmissions were brought about by the Credé maneuver and by induced sneezing, respectively, in differentiated experimental phases. It was shown that the amount of reflex pressure transmission alone totals 89%, which is added onto the given urethral tension and passive pressure transmission. Furthermore, this animal experiment demonstrates that the reflex pressure transmission is created almost solely by the periurethral striated sphincter muscles, whereas the participation of the intraurethral striated sphincter muscles lies at a low 4%.     

Carbon dioxide urethral pressure profiles in males

Carbon dioxide urethral pressure profiles were obtained in a group of continent and incontinent male patients. Cystometry, needle electromyography of the striated urinary sphincter, and cystourethroscopy were also performed in most patients. A characteristic reproducible urethral pressure profile can be obtained in the continent, obstructed, and incontinent groups. The results also showed that the urethral pressure profile is influenced by the activity of the periurethral striated muscle. The urethral profile when performed with other established urodynamic procedures is a useful test in delineating normal and abnormal urinary sphincter function.     

Combined electromyography and gas urethral pressure profilometry before and after transurethral resection of the prostate.

Combined electromyographic and gas urethral pressure profilometry was done on 10 consecutive patients before and 3 months after transurethral resection of the prostate. A significant reduction was found postoperatively in the functional urethral length, whereas the maximum urethral closure pressure remained unchanged. Increase in urethral resistance in prostatic obstruction of the posterior urethra was related to the increase in the functional length of the posterior urethra rather than to mechanical occlusion of the urethral lumen. Periurethral striated muscle activity was recorded from the membranous urethra to the urethrovesical junction with the maximal activity located in the membranous urethra. Marked striated muscle activity also was found consistently at the bladder neck.     

The urodynamic effects of an alpha 1-adrenoceptor agonist on the bladder and urethra of female dogs]

It has been known that alpha 1-adrenoceptors play an important role in urethral contraction. The incompetence of the urethral contraction is a cause of stress incontinence. We studied the urodynamic effects of a selective alpha 1-adrenoceptor agonist (midodrine hydrochloride) on the bladder and urethra of female dogs. Under anesthesia with intravenous chloralose, four doses (0.03, 0.1, 0.3 and 1.0 mg/kg) of midodrine were administered intravenously and urodynamic studies including cystometry, urethral pressure profilometry and electromyography (EMG) of the external urethral sphincter were performed. The administration of midodrine induced a significant increase of the maximum closing pressure in the proximal portion of the urethra (p less than 0.05 at 0.03 mg/kg and p less than 0.01 at 0.1, 0.3, 1.0 mg/kg). There were no significant changes in the functional profile length, the closing pressure at the external sphincters, the maximum bladder pressure, bladder capacity and bladder compliance. The administration of 0.3 mg/kg or more of midodrine produced a significant increase in the mean arterial blood pressure. After midodrine administration, transient increases in the external sphincter EMG activities were recognized. The activities showed the synergistic pattern during the bladder contractions. In conclusion, lower dose administration of a selective alpha 1-adrenoceptor agonist (midodrine) specifically produced an increase of the closing pressure in the proximal portion of the urethra without affecting blood pressure. These results suggest that midodrine is useful for the treatment of stress incontinence in humans.     

Urodynamic evaluation and electrical and pharmacologic neurostimulation

Summary We introduce a rat model that allows simultaneous or independent recording of bladder and sphincteric activity. Via a polyethylene tube inserted into the bladder dome, bladder pressure is measured in response to constant intravesical saline perfusion. The electrical activity of the intra-abdominal urethra (a well-defined striated muscular tube which, in the rat, constitutes the external urethral sphincter) is recorded simultaneously with an electromyography needle electrode. Thus, precise statements can be made about detrusor/sphincter interrelationships. Changes in urodynamic parameters with the anesthetics urethane, methoxyflurane (Metofane), and thiobutabarbital sodium (Inactin) were investigated. High-frequency oscillations in intraluminal bladder pressure could be demonstrated during micturition cycles only in rats anesthetized with urethane or Metofane. As this high-frequency activity is generated by the striated muscle of the intra-abdominal urethra, the external sphincter of the rat is the force behind urine expulsion. The anesthetic Inactin combined with a low intravesical perfusion rate attenuated spontaneous bladder and sphincteric activity and abolished micturition cycles. This rat model can provide accurate and reproducible measurements of urodynamic changes in response to electrical stimulation of the pelvic and pudendal nerves and pharmacologic stimulation with neuropeptides at the lumbosacral spinal cord level. We recommend using this model with urethane or Metofane for physiologic studies of micturition and with Inactin for meticulous neuropharmacologic and electrostimulatory evaluation of urodynamic parameters.     

Can simultaneous perineal sonography and urethrocystometry help explain urethral pressure variations?

Objective: To correlate urodynamic with perineal sonographic findings in pressure variations. Patients and methods: In 15 women presenting with urethral pressure variations a urodynamic evaluation with water filling cystometry, urethral pressure at rest and during coughing and uroflowmetry were performed. During water filling cystometry, there were simultaneous perineal video-sonography and urethrocystometry. Video ultrasound images and urodynamic curves were simultaneously monitored on a computer screen. Results: Simultaneous ultrasound and urodynamic evaluation in the 15 patients revealed movements in two areas leading to urethral pressure variations: activity of the pelvic floor muscles and of the urethral sphincter muscles. For the pelvic floor, we found either slow or fast contractions with, respectively, slow (15–30 cm H₂O for 3–10 sec) or fast (30–130 cm H₂O for 1–3 sec) urethral pressure changes. Urethral sphincter contractions were always fast, resulting in fast pressure changes of 30–170 cm H₂O for 1–3 sec. Conclusion: Evaluation of simultaneous perineal sonography and urethrocystometry shows the association of urethral pressure variations and muscle activity. Urethral pressure variations are caused by the activity of urethral sphincter or pelvic floor muscles. With ultrasound the activity of the urethral sphincter muscle can directly be seen whereas pelvic floor muscle activity is indirectly visible. Pelvic floor muscle contractions are either fast or slow, whereas the urethral sphincter muscle contractions are always fast contractions.     

Urodynamics in spinal shock patients

We investigated 17 spinal shock patients with traumatic complete cord lesions with cystometry, urethral pressure profile, anal and rectal pressure recordings, and electromyography of the pelvic floor sphincters. Bladder filling was accompanied by an elevation of resistance in the bladder neck area, with a concomitant increase of pressure in the external sphincter zone but without a simultaneous increase of the electromyographic activity. These results indicate an increased sympathetic activity in the smooth muscle component of the entire urethra. In the majority of patients the continuous withdrawal pressure profile had higher values in the membranous urethra than the interrupted withdrawal pressure profile had higher values in the membranous urethra than the interrupted withdrawal pressure profile, revealing the importance of sensory afferents from the urethral mucosal receptors in producing artifactual reflex activity in the pelvic floor muscles. In the majority of interrupted withdrawal urethral pressure profiles higher pressures were recorded in the juxtabulbous region than in the mid part of the membranous urethra. A somewhat decreased electromyographic activity was found in the anal and urethral sphincters at rest. It did not often relate to the amount of resistance recorded in either sphincter. High urethral sphincter pressures and somatic activity of the conus medullaris reflexes show that external urethral and anal sphincters escape spinal shock, the primary characteristic of which is areflexia.     

A new approach to electromyography of the external urethral sphincter

Detailed electromyographic investigation of the external urethral sphincter was done as part of a urodynamic evaluation of 119 patients. The sphincter was located by inserting electrodes alongside the urethra. The electromyogram was viewed on an oscilloscope and recorded on paper. Normal and abnormal sphincter electromyograms were defined and the role of sphincter electromyography in urodynamic studies was discussed. It was observed that electromyographic activity does not always correlate with urethral resistance but must be interpreted in conjunction with other urodynamic parameters, such as urethral pressures, urinary flow rates and voiding cystourethrography. In addition, sphincter electromyography provides valuable information to define the various neural pathways involved in micturition and continence.     

Urodynamic studies in acupuncture for women with frequency, urgency and dysuria

Urodynamic measurements were performed before and after acupuncture at 2 different points in 52 women who presented with frequency, urgency and dysuria. Measurements included cystometry, anal sphincter electromyography, urethral pressure profilometry and uroflowmetry. The results of this study showed a significant increase in maximum cystometric capacity and a decrease in peak urinary flow rate after acupuncture at the Sp. 6 point, which has traditionally been used for the treatment of urinary problems. During acupuncture at the Sp. 6 point there were periodic increases in intraurethral pressure at the distal urethra, which were measured with a microtip transducer. Acupuncture-induced detrusor inhibition and external sphincteric contractions were demonstrated. Clinically symptomatic improvement was noted in 22 of the 26 patients who were treated by acupuncture at the Sp. 6 point. Our studies indicated that acupuncture could be used as a simple and effective method to treat female patients with frequency, urgency and dysuria.     

Clinical and urodynamic re-evaluation of combined abdominovaginal Marlex sling operations for recurrent stress urinary incontinence

Sixty-five women underwent combined abdominovaginal Marlex sling procedures for recurrent stress urinary incontinence. Urodynamic evaluation consisted of uroflowmetry and simultaneous pelvic electromyographic (EMG) studies, carbon dioxide cystometry, urethral pressure profilometry, and cystometry and urethroscopy. Cure rates were 75% for urgency incontinence and 95.3% for stress incontinence. The statistically significant improvements in pre- and postoperative urodynamic parameters involved a decrease in uroflow volumes and an increase in urethral functional length, but not in maximum urethral closure pressure. Bladder capacity remained unchanged.     

女性下尿路梗阻的尿流动力学及处理（附42例报告）

１９８５年８月～１９９３年４月对４２例女性下尿路梗阻患者行尿流动力学检查，包括尿流率、膀胱容积压力测定、尿道分布压及尿道外括约肌肌电图，结合Ｂ超及尿道镜观察，全部明确诊断，手术处理及药物治疗，疗效满意。对女性下尿路梗阻的病因，尿流动力学诊断意义及女性膀胱内颈梗阻原因进行讨论。     

Urethral distension as a novel method to simulate sphincter insufficiency in the porcine animal model

Objectives: To describe a novel animal model of intrinsic sphincter deficiency. Methods: The study was carried out on 10 female pigs. Injury to the urethral sphincter was induced by distension of the urethra. This was obtained by using the balloon of an 18‐F Dufour catheter for 5 min followed by its retraction through the urethra without draining the balloon. The urethral pressure profile was evaluated before injury, immediately postinjury and at day 28 postinjury in the experimental group (n = 5), and on day 1 and day 28 in the control uninjured group (n = 5). The maximal urethral closure pressure, the functional urethral length and the area under curve of the urethral pressure profile were measured. Results: The mean maximal urethral closure pressure at the beginning of the experiment was 32 cmH₂O, and the mean functional urethral length was 4.88 cm. The assessment at day 28 showed a reduction of the maximal urethral closure pressure (50% of the control, P > 0.05), the functional urethral length (52.5% of the control, P < 0.05) and the area under curve (52% of the control, P < 0.05) in injured pigs. Histologically, a fibrosis of the sphincter was detected without rupture of the muscle layer in all the samples. Conclusions: The proposed porcine model can be used to obtain intrinsic sphincter deficiency‐like urodynamic findings without rupturing the sphincter. This methodology can be applied to investigate therapies for intrinsic sphincter deficiency.     

A comparative study of various electrodes in electromyography of the striated urethral and anal sphincter in children

The series comprised 41 children aged 6 to 14 years consecutively referred with recurrent urinary tract infection and/or enuresis. Carbon dioxide cystometry was carried out in the supine and the erect position and combined with simultaneous electromyography (EMG). The external urethral sphincter was examined with a ring electrode mounted on a urethral catheter, while recordings from the striated anal sphincter were based on an anal plug electrode and perianal electrocardiographic (ECG) skin electrodes: 211 EMG and cystometric examinations were performed and all three methods gave satisfactory results. Correlation between them was good, as was reproducibility. Perianal surface ECG electrodes are recommended for the evaluation of functional disturbances of the external sphincter. They are painless, easy to use, and are well tolerated by the patient.     

女性膀胱流出道梗阻的影像尿动力学检查特点分析

目的 探讨女性膀胱出口梗阻(BOO)患者影像尿动力学检查特点及意义.方法 女性BOO患者42例,根据梗阻部位分为膀胱颈梗阻(7例)、中段尿道梗阻(13例)、远端尿道梗阻(15例)、尿道外口梗阻(3例)、盆腔器官重度脱垂(4例)5组.患者术前均行影像尿动力学检查,比较5组病例Qmax、最大膀胱容量、Pdet atQmax、残余尿、逼尿肌无抑制收缩、双侧肾积水等指标.结果 42例患者中以尿频、尿急等储尿症状为主者17例(40.5%),以排尿困难等为主者4例(9.5%),混合症状者21例(50.0%).42例Qmax(10.9±5.6)ml/s、最大膀胱容量(253±140.7)ml、Pdet atQmax(53.3±25.7)cm H2O、残余尿量(76.2±70.3)ml,逼尿肌无抑制收缩者21例(50.0%);5组患者比较:最大膀胱容量差异无统计学意义;膀胱颈梗阻组Pdet atQmax最高、残余尿量最多、Qmax最低、肾积水比例最高,与其他各组比较差异有统计学意义(P<0.05);逼尿肌无抑制收缩在外括约肌部梗阻患者中10例(76.9%),与其他各组比较差异有统计学意义(P<0.05).结论 影像尿动力学检查能有效评估女性BOO下尿路功能,提示梗阻部位并指导临床治疗.女性BOO患者中膀胱颈梗阻程度是影响上尿路损害的主要因素.     

The effect of bladder training, pelvic floor muscle training, or combination training on urodynamic parameters in women with urinary incontinence. Continence Program for Women Research Group.

The purpose of this study was to compare the effect of three conservative interventions: pelvic floor muscle training, bladder training, or both, on urodynamic parameters in women with urinary incontinence. Two hundred four women with genuine stress incontinence (GSI) or detrusor instability with or without GSI (DI +/- GSI) participated in a two-site trial comparing pelvic floor muscle training, bladder training, or both. Patients were stratified based on severity of urinary incontinence, urodynamic diagnosis, and treatment site, then randomized to a treatment group. All women underwent a comprehensive standardized evaluation including multi-channel urodynamics at the initial assessment and at the end of 12 weeks of therapy. Analysis of covariance was used to detect differences among treatment groups on urodynamic parameters. Post-treatment evaluations were available for 181 women. No differences were found among treatments on the following measurements: maximum urethral closure pressure, mean urethral closure pressure, maximum Kegel urethral closure pressure, mean Kegel urethral closure pressure, functional urethral length, pressure transmission ratios, straining urethral axis, first sensation to void, maximum cystometric capacity, and the MCC minus FSV. The effect of treatment did not differ by urodynamic diagnosis. Behavioral therapy had no effect on commonly measured urodynamic parameters. The mechanism by which clinical improvement occurs remains unknown. Neurourol. Urodynam. 18:427-436, 1999.     

Comparison of preoperative and postoperative pressure transmission ratio and urethral pressure profilometry in patients with successful outcome following the vaginal wall patch sling technique

AIMS: We studied preoperative and postoperative pressure transmission ratio (PTR) and urethral pressure profilometry in patients undergoing the vaginal wall patch sling technique as a first surgical approach for genuine stress incontinence (GSI) with urethral hypermobility. The specific aims were to determine the exact urodynamic parameters, if any, that may be improved postoperatively and to report the urodynamic outcome of the vaginal wall patch sling technique in successful cases. METHODS: Preoperatively, all patients had a positive standing stress test, urethral hypermobility on Q-tip testing, and normal postvoid residual volume. On urodynamics, all patients had equalization of maximum urethral closure pressure (MUCP) on cough profilometry, and absence of detrusor contractions on subtracted cystometry. The PTR for each cough was calculated. Cough spikes were assigned locations in the first, second, third, or fourth quartile of the functional urethral length (FUL). Urethral pressure profilometry was performed at bladder capacity in the sitting position. All urodynamic tests were repeated 3-6 months postoperatively. A two-tailed t-test was used for statistical analysis. RESULTS: Forty-eight patients demonstrated successful outcome at initial follow up and constituted the study population. There was a statistically significant increase in MUCP at stress as well as a statistical increase in PTR in the first, second, and third quartiles of the FUL postoperatively. CONCLUSIONS: The vaginal patch sling technique appears to restore continence both by buttressing the urethra at times of stress as well as repositioning the proximal urethra into the intra-abdominal pressure zone, thus, enhancing pressure transmission to the proximal urethra.     

一种用于雌性大鼠尿动力学研究的新方法

目的 建立一种适用于雌性大鼠尿动力学研究的新检测方法,应用该方法测定成年雌性大鼠尿动力学各项参数正常范围.方法 33只成年雌性大鼠乌拉坦腹腔麻醉,尿道内置入2根3 F输尿管导管,分别连接尿动力学检查仪压力传感器及微量注射泵,同时由肛门置入直肠测压气囊管与腹压传感器连接.应用尿动力学检查仪测定大鼠充盈期膀胱压力变化和静态尿道压力图的各项参数.结果 正常成年雌性大鼠尿动力学参数测定值如下:(1)充盈期膀胱压力参数:腹压漏尿点压(ALPP)、喷嚏漏尿点压(SLPP)、排尿压(VP)及膀胱最大容量(MBV)分别为(28.06±5.85)、(23.00±5.96)、(25.39±6.23)cm H2O及(1.21±0.52)ml;(2)静态尿道压力图参数:最大尿道压(MUP)、最大尿道闭合压(MUCP)及功能性尿道长度(FUL)分别为(17.13±4.55)、(14.87±3.77)cm H2O及(14.23±2.64)mm.结论 这种新方法可方便地应用于雌性大鼠的尿动力学研究,更为接近临床所用的方法,因此更具可比性.