Urethral closure pressures among primiparous women with and without levator ani muscle defects

Introduction and hypothesis

Vaginal birth is an established risk factor for levator ani (LA) defects and incontinence. We hypothesized an association between urethral pressure profiles and LA defects.

Methods

One hundred sixty primiparous women, 9?C12?months postpartum, were assessed with MRI for LA defects, urodynamic testing, and instrumented speculum for vaginal closure force. Urodynamic testing included resting maximal urethral closure pressure (MUCP) and urethral closure pressure with a pelvic floor contraction or Kegel (KUCP). We examined the relationships between MUCP, KUCP, LA defect status, and vaginal closure force.

Results

There was no significant association between MUCP or KUCP in women with and without LA defects (p?=?0.94, p?=?0.95). Additionally, there was no correlation between MUCP and vaginal closure force (r?=?0.06, p?=?0.41), and a weak correlation between KUCP and vaginal closure force (r?=?0.20, p?=?0.01).

Conclusions

In this population, urethral pressure profiles are unrelated to LA defect status after vaginal birth, indicating that the mechanism responsible for LA damage spares the urethra.     

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.     

THE EFFECT OF SIMULATED BIRTH TRAUMA AND/OR OVARIECTOMY ON RODENT CONTINENCE MECHANISM. PART I: FUNCTIONAL AND STRUCTURAL CHANGE

PURPOSE: We examined the changes in the lower urinary tract after delivery, intravaginal ballooning and/or ovariectomy. MATERIALS AND METHODS: The study included 10 virgin and 48 primiparous pregnant rats. Cystometry and the stress/sneeze test were performed in virgin and postpartum rats shortly after delivery and at 8 weeks before sacrifice. Half of the delivered animals underwent intravaginal balloon dilation. Four weeks later half in each group underwent ovariectomy. The rats were subdivided into group 1--delivery, group 2--delivery plus balloon inflation, group 3--delivery plus ovariectomy and group 4--delivery plus balloon inflation plus ovariectomy. Tissues from the bladder, bladder neck, urethra and levator were collected, analyzed by electron microscopy, and immunostained for caveolin-1, caveolin-3 and neuronal nitric oxide synthase. RESULTS: Higher bladder capacity was detected in postpartum than in virgin rats. Urine leakage on stress/sneeze testing increased significantly in groups 2 and 4. Electron microscopy revealed a significant decrease in sarcolemma caveolae in the smooth muscle of the bladder and urethra in groups 2 to 4. In the bladder neck in group 3 caveolae were increased in smooth muscle. In groups 2 to 4 in the smooth muscle of the bladder and urethra caveolin-1 was significantly decreased. Caveolin-3 and neuronal nitric oxide synthase in striated muscle also significantly decreased in groups 2 to 4. CONCLUSIONS: These findings suggest that birth trauma simulated by ballooning and ovariectomy may contribute to stress urinary incontinence. The alteration in smooth muscle caveolae as well as the membrane protein caveolin may have a role in functional alterations caused by birth trauma and ovariectomy.     

Effects of vaginal trauma and oophorectomy on the continence mechanism in rats

PURPOSE: To establish an animal model for studying the effects of vaginal trauma and oophorectomy on the continence mechanism in rats. METHODS: Ninety-six female rats were used in the experiments. The rats were divided into 8 groups that received either no treatment (control), or single vaginal trauma at 0 day and 4 weeks, multiple vaginal traumas, oophorectomy at 4 and 12 weeks, and combined oophorectomy and single vaginal trauma or multiple vaginal traumas at 4 weeks. In vivo experiments were performed to determine abdominal leak point pressure (ALPP) by recording the intravesical pressure obtained during compression of the lower abdomen. In vitro urethral contractility experiments were then performed using isolated urethra and electrical field stimulation, acetylcholine, and norepinephrine. Finally, histological study of the urethral muscles and paraurethral structures was performed. RESULTS: Single or multiple vaginal traumas resulted in a significant reduction of ALPP. The reduced ALPP recovered at 4 weeks after single vaginal trauma. Oophorectomy did not significantly affect ALPP compared to controls; however, when oophorectomy was combined with multiple vaginal traumas, a significant reduction in ALPP occurred. Urethral contractility was reduced after multiple vaginal traumas but was not significantly different from the control after oophorectomy. Histological studies revealed disruption of the ventral part of striated muscles after single or multiple vaginal traumas. Degenerative and hyalinization changes were noted in submucosal and muscle layers after oophorectomy combined with multiple vaginal traumas. CONCLUSIONS: Vaginal trauma can injure the urethral muscles and nerves. Single or multiple vaginal traumas can induce denervation of periurethral muscles and reduce ALPP. With a period of recovery, the urethral resistance increases and ALPP returns. Oophorectomy mainly affected the intrinsic urethral closure mechanism and resulted in a nonsignificantly reduced ALPP; however, a significant reduction of ALPP developed when oophorectomy was combined with multiple vaginal traumas.     

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.     

Sequential assessment of urodynamic findings before and after tension-free vaginal tape (TVT) operation for female genuine stress incontinence

OBJECTIVES: To sequentially compare the urodynamic findings in patients with genuine stress incontinence (GSI) before and after tension-free vaginal tape (TVT) operation. PATIENTS AND METHODS: Between January 2001 and January 2002, 24 consecutive patients with GSI who completed multi-channel urodynamic study and 20-minute pad test before operation and at 3, 6, and 12 months after operation were enrolled. The sequential urodynamic findings of each case were compared and analyzed. RESULTS: The mean age of the 24 patients was 60.6+/-10.7 years with the parity of 3.5+/-1.4. No statistical differences in voiding and storage functions before and after TVT operation were noted. In contrast, significant changes of stress urethral pressure profile (sUPP) including maximal urethral pressure, maximal urethral closure pressure, functional urethral length, urethral closure area and continence area were observed at 6 and 12 months postoperatively ( p<0.03 ). The median pad weight test decreased from 72g (range 10-220) to 0g 3 months after operation and remained unchanged at 6 and 12 months postoperatively. CONCLUSIONS: This prospective study demonstrates that TVT operation, if done properly, does not significantly impair voiding and storage functions. The significantly increased sUPP parameters may contribute, at least in part, to the high cure rate of TVT operation.     

The risk of postoperative urinary incontinence after surgical treatment of genital prolapse

Full urodynamic assessment, including urethral profiles at rest and under stress, was made before and after surgery for severe urogenital prolapse in 40 continent women. Profilometry was also recorded after reduction of the prolapse by a vaginal pessary. The aim of this study was to try to determine criteria to prevent postoperative incontinence. After surgery, 6 patients (15%) became stress incontinent. The operation tends to diminish urethral obstruction (diminution of the residual volume) and negatively affects urodynamic urethral parameters (diminution of the residual continence area). The pessary test was not predictive of postoperative incontinence. Preoperative transmission ratio <100% and/or maximum urethral closure pressure <35 cmH₂O are proposed as predisposing factors for postoperative iatrogenic incontinence. Therapeutic implications are discussed.     

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.     

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.     

Relationship between urethral and vaginal pressures during pelvic muscle contraction

Condensation is the performance of an effective pelvic muscle contraction increases urethral and vaginal pressures and is independent of demographic, clinical, and urodynamic factors. Our objective was to examine the relationship between urethral closure pressure and vaginal pressure during a pelvic muscle contraction in minimally trained women. Our secondary aim was to determine whether demographic, clinical, or urodynamic factors predict pelvic muscle contraction performance. Two hundred two women with urinary incontinence underwent multichannel urodynamic evaluation, including urethral profilometry and measurement of vaginal pressure during pelvic muscle contraction. One hundred forty-four women were diagnosed with genuine stress incontinence, 28 with detrusor instability, and 30 with mixed incontinence. Urethral and vaginal pressures correlated significantly during pelvic muscle contraction (P ≤ 0.006). The ability to perform an adequate pelvic muscle contraction was independent of subject age, parity, hormonal or hysterectomy status, clinical severity, urethral support, and urethral profilometry measures (P ≥ 0.42). We conclude that increases in urethral pressure correlate significantly with increases in vaginal pressure during pelvic muscle contraction. Women with urinary incontinence are able to perform effective pelvic muscle contractions independent of their age, clinical incontinence severity, urethral support, and urethral profilometry values. Neurourol. Urodynam. 16:553–558, 1997. © 1997 Wiley-Liss, Inc.     

A magnetic device for increasing the urethral resistance to flow: an experimental study in female dogs

OBJECTIVE: To test a new magnetic device for increasing the urethral resistance to flow in a dog model, and thus provide a potential mechanical device for the treatment of incontinence in women. MATERIALS AND METHODS: The study comprised 12 female mongrel dogs; three dogs were used to study the effect on urethral resistance of inserting a vaginal magnet (control experiment) and five were assessed in a urodynamic study. With the animals under general anaesthesia, the bladder and the urethra were exposed by a low midline incision. One magnet, embedded in a silicon layer, was placed on the anterior side of the urethra 3 cm distal to the bladder neck and fixed with a few sutures. To increase the urethral resistance as required, a second magnet was inserted into the vagina and the device activated. Urethral pressure profiles and leak-point pressures were recorded in the anaesthetized animals under resting conditions and after the urethra was compressed between the magnets. Recordings were also made after pharmacological blockade of the urethral musculature. In four additional dogs, chronic experiments were conducted to evaluate the effect of continuous compression of the urethra and the vaginal wall for 14 days. RESULTS: Urethral compression between the magnets resulted in a doubling of the maximal pressure in the proximal urethra and in a threefold increase of the leak-point pressure. After pharmacological denervation of the urethra the differences between the control pressures and those after activating the device were even greater, although not significantly so. After 2 weeks of continuous compression of the vaginal wall and the urethra between the magnets there was no detectable tissue damage. CONCLUSION: These results suggest that the magnetic device can efficiently increase urethral pressure and that prolonged compression caused no apparent damage to the urethra or vagina. It may therefore be a useful potential method of providing urinary continence in women.     

Stamey endoscopic vesical neck suspension in female urinary stress incontinence: Results and changes in various urodynamic parameters

A total of 32 female patients with urinary stress incontinence who underwent a Stamey endoscopic bladder neck suspension were clinically and urodynamically studied pre- and postoperatively. Complete cure was obtained in 78% of the patients and improvement in 6%, the overall success rate being 84% for a mean follow-up of 11.1 months (range 6–19). Complications occurred in 22% of the patients. Comparison of the pre- and postoperative urodynamic data revealed that the maximum urine flow rate, functional urethral length and maximum urethral closure pressure were changed significantly after operation. In addition, when studying the abdominal pressure transmission to the entire urethra during stress, there was a significant conversion of negative to positive pressure transmission after surgical repositioning of the urethra.     

Preoperative screening for latent stress incontinence in women with cystocele

A preoperative urodynamic investigation with and without a vaginal pessary ring including simultaneous urethrocystometry and urethral pressure profiles in supine and standing position during coughing was evaluated in 41 continent women with cystocele. Following the application of the vaginal pessary ring, loss of urine was demonstrated in six patients, in whom a negative urethral closure pressure was found only when the pessary ring was inserted, suggesting that latent stress incontinence might become manifest after surgical repair of the cystocele. These patients were all continent during the follow-up period of 12–18 months after Manchester repair combined with urethrocystopexy. The remaining 35 patients with normal urodynamic registrations with and without an inserted pessary ring had no signs of urinary incontinence during the follow-up period after the Manchester repair. Thus, the present urodynamic screening was found to be valuable for preoperative selection of an adequate surgical method in order to avoid postoperatively manifest stress incontinence after anterior colporaphy.     

压力性尿失禁动物模型的建立

目的 探讨压力性尿失禁(SUI)老鼠模型建立的有效方法,为深入研究SUI的发病机制提供有价值的研究对象.方法 50只Sprague-Dawley大鼠雌雄合笼(合笼比例4∶1),分娩后随机分成两组,即第一组(12只)和第二组(28只).第一组对其常规饲养,不做任何特殊处理.第二组对已育大鼠采用阴道球囊扩张4 h模拟难产,两周后重复一次,常规饲养1个月后切除双侧卵巢.8周后,两部分大鼠均行尿流动力学检查测膀胱最大容量(MBC)和腹部漏尿点压力(ALPP)及喷嚏实验,尿动力学检测完毕后从第二组随机筛选出压力性尿失禁成年已育雌性大鼠模型(12只).结果 对照组和实验组大鼠漏尿点压力值分别为(48.00±1.74)cmH2O和(32.94±1.63)cmH2O,差异有统计学意义(p＜0.05);最大膀胱容量为(2.02±0.19)ml和(1.29±0.16)ml,差异有统计学意义(p＜0.05);喷嚏实验见实验组有13只大鼠表现阳性(阳性率52%),对照组全部阴性.结论 阴道球囊扩张联合双侧卵巢切除可以成功建立压力性尿失禁大鼠模型.     

Increased proximal urethral sensory threshold after radical pelvic surgery in women

AIM: To identify factors that potentially influence urethral sensitivity in women. PATIENTS AND METHODS: The current perception threshold was measured by double ring electrodes in the proximal and distal urethra in 120 women. Univariate analysis using Kaplan-Meier models and multivariate analysis applying Cox regressions were performed to identify factors influencing urethral sensitivity in women. RESULTS: In univariate and multivariate analysis, women who had undergone radical pelvic surgery (radical cystectomy n = 12, radical rectal surgery n = 4) showed a significantly (log rank test P < 0.0001) increased proximal urethral sensory threshold compared to those without prior surgery (hazard ratio (HR) 4.17, 95% confidence interval (CI) 2.04-8.51), following vaginal hysterectomy (HR 4.95, 95% CI 2.07-11.85), abdominal hysterectomy (HR 5.96, 95% CI 2.68-13.23), or other non-pelvic surgery (HR 4.86, 95% CI 2.24-10.52). However, distal urethral sensitivity was unaffected by any form of prior surgery. Also other variables assessed, including age, concomitant diseases, urodynamic diagnoses, functional urethral length, and maximum urethral closure pressure at rest had no influence on urethral sensitivity in univariate as well as in multivariate analysis. CONCLUSIONS: Increased proximal but unaffected distal urethral sensory threshold after radical pelvic surgery in women suggests that the afferent nerve fibers from the proximal urethra mainly pass through the pelvic plexus which is prone to damage during radical pelvic surgery, whereas the afferent innervation of the distal urethra is provided by the pudendal nerve. Better understanding the innervation of the proximal and distal urethra may help to improve surgical procedures, especially nerve sparing techniques.     

Urodynamic and Ultrasonographic Evaluation after Continence Surgery

Our objective was to evaluate urodynamic and ultrasonographic findings after continence surgery. The study consisted of three groups of women according to the surgery performed: group I (Burch colposuspension) with 12 patients; group II (Kelly–Kennedy plication) with 10 patients; and group III (Gittes surgery) with 9 patients. Urodynamic study was done preoperatively and after surgery (on the 7th and 30th postoperative days, and at least 6 months after surgery) and ultrasonography of the bladder neck was performed to evaluate its position in relation to the inferior edge of the pubic symphysis and its mobility, both preoperatively and after surgery (30th postoperative day). All patients remained continent. We observed an increase in the first desire to void and maximum cystometric capacity after 6 months in groups I and II, respectively. There was no change in the urethral closure pressure profile in the three groups. Elevation of the bladder neck and decrease of its mobility were found by ultrasonography. Urinary continence after surgery is not the result of alterations in the urethral closure pressure profile, but rather of an elevation in the bladder neck and limitation of its mobility, which probably improves the abdominal pressure transmission rate to the proximal urethra.     

Urodynamic prolapse reduction alters urethral pressure but not filling or pressure flow parameters

PURPOSE: To test the hypothesis that advanced stages of pelvic organ prolapse can result in a functional obstruction of the urethra, we studied the effects of manual prolapse reduction on urodynamic and urethral electromyographic parameters in women with stage III and IV pelvic organ prolapse. MATERIALS AND METHODS: Women with advanced pelvic organ prolapse undergoing clinical multichannel urodynamics with concentric needle electromyography of the urethra were invited to participate in this institutional review board approved study. Women underwent filling cystometry and electromyography with prolapse everted and with prolapse reduced. Women were randomized to cystometry order (reduced vs everted). All subjects underwent a third study with prolapse reduction. Maximum urethral closure pressure and quantitative electromyography of the striated urethral sphincter were determined at maximum cystometric capacity. During the pressure flow study voiding parameters, including urethral electromyography quieting, were determined. The nonparametric paired sign test was used to evaluate differences in urodynamic parameters and quantitative electromyography with pelvic organ prolapse reduced and unreduced. Results were considered significant at the 5% level. RESULTS: The 31 participants had mean age of 60 years (range 36 to 78) and 83% were white. There were no clinically significant differences in maximum cystometric capacity, voided volume, maximal flow and detrusor pressure at maximal flow or time to maximal flow between the reduced and everted prolapse states. Prolapse reduction resulted in a clinically and statistically significant decrease in maximum urethral closure pressure (-31%) but it had no impact on quantitative urethral electromyography. CONCLUSIONS: These findings demonstrate that, although prolapse reduction significantly decreases maximum urethral closure pressure, it does not alter intrinsic neuromuscular activity of the striated urethral sphincter. Prolapse reduction does not alter any other filling or pressure flow parameter.     

雌性大鼠尿流动力学检查指标的年龄变化

目的:探讨不同年龄段雌性大鼠尿动力学指标的变化趋势.方法:取4组年龄分别为6、12、18和24个月的雌性成年大鼠,乌拉坦腹腔麻醉,尿道内置人2根3F自制测压导管,分别与尿动力学检查仪的压力传感器及微量注射泵连接,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并描记静态尿道压力图.结果:雌性大鼠膀胱漏尿点压、最大膀胱排尿压、腹压漏尿点压以及最大膀胱容量在各年龄组无明显差别(P＞0.05);而最大尿道压、最大尿道闭合压以及功能性尿道长度随着年龄增加而显著下降(P＜0.05),但在≥18个月的两组雌性大鼠中无明显差异.结论:老龄化对雌性大鼠静态尿道压力参数的变化起重要作用,提示年龄可能是尿道变化特别是压力性尿失禁的重要危险因素.     

女性尿道中静态尿道压力分布特点的研究

目的：探讨在女性尿道不同部位和不同方向上静态尿道压力图（RUPP）压力的分布特点。方法：本研究共包括因各种原因需做尿动力学检查的成年女性患者55例,年龄（41±11）岁,其中尿流动力学检查无异常者8例,压力性尿失禁19例,其他诊断（包括OAB、膀胱收缩无力等）28例。采用恒压恒速灌注法测压,将测压孔分别朝向尿道前壁（12点）、后壁（6点）、左侧壁（3点）及右侧壁（9点）四个方向描记RUPP,采用配伍区组方差分析进行统计学分析。结果：前壁的最大尿道闭合压（MUCP）最高（P％0．01）,后壁的MUCP最低（P〈0．001）,左右两侧MUCP无明显差异（P=0．571）;前壁的功能尿道长度（FUL）最短（P〈0．01）,后壁的FUL最长（P〈0．001）,左右两侧FUL无统计学差异（P=0．717）;RuPP曲线均呈抛物线形,高压区和MUCP的最大值位于尿道中段或中远段交界处。结论：本研究结果显示,静态尿道压力图在女性尿道压力分布上,前后壁方向上具有显著的方向性变异,而左右两侧具有对称性和一致性。尿道压力图的压力分布特点与女性尿道壁的组织结构和尿道腔的形态密切相关。     

Intraurethral Ultrasonography: Correlation of Urethral Anatomy with Functional Urodynamic Parameters in Stress Incontinent Women

To determine whether differences in functional urodynamic parameters can be explained by changes in urethral anatomy, 39 patients underwent intraurethral ultrasonography to obtain a 360° view of the urethra. The point of maximal rhabdosphincter thickness was identified in all patients. The thickness, circumference and area of the urethral smooth and skeletal muscle layers were calculated. Data from patient histories and urodynamic evaluations were compared with this anatomical survey. The urodynamic diagnoses were as follows: 10 patients were normal, 24 had genuine stress incontinence and 5 had intrinsic sphincter deficiency. These patients had decreasing rhabdosphincter thicknesses of 3.91, 3.35 and 2.70 mm (P= 0.048). A weak linear relationship was found between maximal urethral closure pressure and rhabdosphincter (r= 0.40, P= 0.013) and longitudinal smooth muscle (r= 0.35, P = 0.027) thickness. It was concluded that a loss of urethral resistance as measured by maximal urethral closure pressure is associated with changes in urethral anatomy identified by intraurethral ultrasonography.