Pathophysiology of urinary incontinence after radical prostatectomy

To define the origin of urinary incontinence after radical prostatectomy urodynamic studies in 24 incontinent patients were compared to those of 13 continent patients. A statistically significant difference between incontinent and continent patients was found for the mean functional profile length (2.1 versus 3.6 cm., respectively, p less than 0.001), maximal urethral closure pressure (39 versus 74 cm. water, respectively, p less than 0.001) and maximal urethral closure pressure during voluntary contraction of the external sphincter (107 versus 172 cm. water, respectively, p less than 0.002). The differences among maximal detrusor pressure, initial bladder volume at which a detrusor contraction occurs, maximal cystometric capacity and residual urine were not statistically significant between the 2 groups. Urethral instability was present in 1 of the 24 incontinent patients (4.2%) and in none of the 13 continent patients, while detrusor instability was present in 6 (25%) and 3 (23.1%), respectively. Urethral and detrusor instability correlated poorly with incontinence (correlation coefficients 0.123 and 0.021, respectively). The appearance of the bladder outlet on voiding cystourethrography was correlated with urodynamic parameters and the presence or absence of continence. Tubularization above the level of the external sphincter was present in continent but absent in incontinent patients. Continence after radical prostatectomy is dependent upon sphincteric efficiency, which may be influenced by the anatomical configuration of the reconstructed bladder outlet and the integrity of the distal urethral sphincteric mechanism.     

Effect of radical prostatectomy on sensory threshold and pressure transmission

PURPOSE: The mechanisms involved in post-radical prostatectomy incontinence remain unclear despite previous anatomical and functional studies. In addition, the factors responsible for the restoration of continence are not well studied. To improve our understanding of the alterations in continence mechanisms, we prospectively investigated the temporal changes in urodynamic parameters after radical prostatectomy. MATERIALS AND METHODS: Cystometry, urethral pressure profilometry and posterior urethral sensory threshold measurements were performed in patients undergoing radical prostatectomy. Preoperative pressure transmission was determined by the maximal urethral pressure divided by the maximal abdominal pressure during cough maneuvers at a bladder volume of 200 ml. Postoperative sensory threshold, pressure transmission (% of pressure transmission), maximal urethral closure pressure and functional sphincter length were measured 6 weeks and 6 months after prostatectomy. These parameters were compared between continent and incontinent patients. RESULTS: Preoperative and postoperative urodynamic studies were completed in 34 patients. The continence rate after 6 weeks was 18% (6 patients) and improved to 82% (28) after 6 months. Preoperatively sensory threshold was 16 +/- 11 mA. After 6 weeks and 6 months, respectively, sensory threshold was significantly higher in incontinent (84 +/- 11 mA., 70 +/- 8 mA.) compared to continent (65 +/- 8 mA., 41 +/- 12 mA.) patients. Preoperative proximal urethral sensory threshold was not correlated with degree of postoperative incontinence determined by pad tests. Pressure transmission was not different in continent and incontinent patients postoperatively. After 6 weeks and 6 months, respectively, pressure transmission was 77% and 91% in continent, and 37% and 58% in incontinent patients (p = 0.04, p = 0.03). Maximal urethral closure pressure was significantly higher in continent patients (35 +/- 6 cm. H2O) compared to incontinent patients (11 +/- 9 cm. H2O). Sphincter length decreased from 50 mm. preoperatively to 24 mm. after 6 weeks and 25 mm. after 6 months. There was no difference in sphincter length between continent and incontinent patients. CONCLUSIONS: Posterior urethral sensitivity and pressure transmission are impaired immediately after prostatectomy. An improvement in these parameters after 6 months is associated with the restoration of continence. These observations suggest that urinary continence after radical prostatectomy depends on the integrity of posterior urethral sensation and the efficiency of pressure transmission.     

Maximum urethral closure pressure and sphincter volume in women with urinary retention

PURPOSE: In 1988 a syndrome of isolated urinary retention in young women that is associated with electromyographic abnormality of the striated urethral sphincter was described. It was hypothesised that urinary retention resulted from a failure of sphincter relaxation. The electromyographic abnormality causes overactivity of the muscle and may induce changes of work hypertrophy. If the hypothesis that the electromyographic abnormality is the cause of urinary retention is correct, we would expect the urethral sphincter to be enlarged and the urethral pressure profile to be increased in these women. We evaluated the role of static urethral pressure profilometry and transvaginal ultrasound in women in urinary retention. MATERIALS AND METHODS: A total of 66 women in complete or partial urinary retention underwent electromyography of the striated urethral sphincter using a concentric needle electrode, followed by urethral pressure profile and/or urethral sphincter volume measurement by transvaginal ultrasound. RESULTS: Maximum urethral closure pressure plus or minus standard deviation was significantly increased in patients with versus without the electromyographic abnormality (103 +/- 26.4 versus 76.7 +/- 18.4 cm. water, p <0.001). Maximum urethral sphincter volume was also increased in women with versus without the abnormality (2.29 +/- 0.64 versus 1.62 +/- 0.32 cm.3, p <0.001). CONCLUSIONS: The results of this study are consistent with the hypothesis that a local sphincter abnormality is the cause of urinary retention in a subgroup of women. Urethral pressure profilometry and sphincter volume measurement are useful for assessing these cases, especially when sphincter electromyography is not readily available.     

The significance of the open bladder neck associated with pelvic fracture urethral distraction defects.

PURPOSE: As a result of pelvic fracture urethral distraction defects, urinary continence relies predominantly on intact bladder neck function. Hence, when cystoscopy and/or cystography reveals an open bladder neck before urethroplasty, the probability of postoperative urinary incontinence may be significant. Unresolved issues are the necessity, the timing and the type of bladder neck repair. We report the outcome of various therapeutic options in patients with pelvic fracture urethral distraction defects and open bladder neck. We also attempt to identify prognostic factors of incontinence before urethroplasty. MATERIALS AND METHODS: We retrospectively reviewed the records of 15 patients with a mean age of 30 years in whom an open bladder neck was identified before posterior urethroplasty between January 1981 and October 1997. RESULTS: Of the 15 patients 6 were continent and 8 were incontinent postoperatively. One patient underwent artificial urethral sphincter implantation simultaneously with pelvic fracture urethral distraction defect repair and was dry postoperatively without sphincter activation. Average bladder neck and prostatic urethral opening on the cystourethrogram before urethroplasty was significantly longer in incontinent (1.68 cm.) than in continent (0.9 cm.) patients. Of the 8 patients who were incontinent 6 underwent bladder neck reconstruction, 1 artificial urinary sphincter and 1 periurethral collagen implant. Five patients with bladder neck reconstruction are totally continent and 1 requires 1 pad daily. The patient who underwent collagen implant requires 2 pads daily and the patient who received an artificial urethral sphincter has minor urge leakage. CONCLUSIONS: Open bladder neck before urethroplasty may herald postoperative incontinence which may be predicted by radiographic and cystoscopic features. Evaluation of the risk of postoperative incontinence may be valuable, and eventually guide the necessity and timing of anti-incontinence surgery, although our preference remains to manage the pelvic fracture urethral distraction defects and bladder neck problem sequentially. Bladder neck reconstruction provides good postoperative continence rates and is our technique of choice.     

Improved continence after radical retropubic prostatectomy using two pubo-urethral suspension stitches

OBJECTIVES: To determine if placement of urethral suspension stitches during radical retropubic prostatectomy improves postoperative urinary continence. METHODS: Between January 1997 and January 1998 we performed radical retropubic prostatectomy on 50 men. The first 25 consecutive men had their surgery without urethral suspension stitches while the next 25 received placement of two anastomotic urethral suspension stitches anchored to the lower portion of the pubic bone. Patients were interviewed six months postoperatively and each underwent valsalva leak-point pressure measurement. Patients were categorized as either completely continent (requiring no pads and having no measurable valsalva leak point), socially continent (zero or one pad per day), or incontinent (two or more pads per day). RESULTS: In the urethral suspension group, 8/25 (32%) patients were completely continent and did not have a measurable valsalva leak-point pressure while 3/25 (12%) without urethral suspension were completely continent. Of the remaining patients in the urethral suspension group, 13/17 (76%) patients were socially continent while 4/17 (24%) were incontinent. The mean valsalva leak-point pressure in the 17 patients with suspension stitches was 89.6 +/- 21.6 cm H2O. In the patients without urethral suspension, there were 22 patients who had some degree of incontinence. Among non-stitch patients, 13/22 (59%) were socially continent while 9/22 (41%) were incontinent. The average valsalva leak-point pressure in these patients was 74.0 +/- 16.7 cm H2O, which was significantly lower than those with the suspension (p = 0.015). CONCLUSIONS: Placement of anastomotic urethral suspension stitches during radical retropubic prostatectomy may increase the likelihood of complete postoperative urinary continence. The urethral suspension stitches also increase valsalva leak-point pressure, which may improve the percentage of patients with socially acceptable incontinence.     

Experimental studies for urinary incontinence. Effect of beta 2-agonists on the vesicourethral function

Terbutaline and clenbuterol, which are both selective beta 2-adrenoceptor agonists, produced a concentration-dependent decrease in contractile force of in vitro rabbit detrusor and proximal urethral smooth muscle. Conversely, terbutaline and clenbuterol produced a concentration-dependent increase in basal tension of in vitro rabbit external urethral striated muscle. Clenbuterol, orally administrated, produced an increase in urinary bladder capacity in cystometry and also an increase in maximal urethral closure pressure in urethral pressure profile. These results suggest that the beta 2-adrenoceptor agonist may be beneficial for urinary incontinent patients.     

Striated sphincter participation in distal passive urinary continence mechanisms: studies in male subjects deprived of proximal sphincter mechanism.

Striated urethral sphincter function was studied in passive incontinent and continenet male subjects who were deprived of the proximal sphincter mechanism. Functional assessment of striated urethral sphincter include electromyography and electrostimulation. Varying degrees of diminished striated sphincter excitability and reflex activity were observed in passive incontinent male subjects who also had varying degrees of somatomotor neuron lesions. The studies indicate that the participating role of periurethral striated musculature in distal passive continence mechanisms cannot be ignored.     

Perfusion sphincterometry for objective evaluation of postprostatectomy intrinsic sphincter deficiency

OBJECTIVES: Male urinary incontinence secondary to intrinsic sphincter deficiency (ISD) is a possible complication of transurethral resection of the prostate (TURP) or radical prostatectomy (RP). For objective assessment of urinary sphincteric competence, we used perfusion sphincterometry (PS) to measure the retrograde urethral perfusion pressure (RUPP). METHODS: A retrospective and prospective analysis of 60 neurologically normal patients of varying continence status was performed. The subjects were divided into three groups: continent patients with no previous prostate surgery (group 1), continent patients after prostatectomy (group 2), and incontinent patients after prostatectomy (group 3). All patients underwent PS with the technique described. All incontinent patients (group 3) had a filling cystometrogram (CMG) to rule out detrusor instability. RESULTS: Continent patients with no prior prostate surgery (group 1) had a mean RUPP of 101 +/- 16 cm H2O; continent postprostatectomy patients (group 2) had a mean RUPP of 77 +/- 14 cm H2O; and incontinent postprostatectomy patients (group 3) had a mean RUPP of 36 +/- 11 cm H2O. The differences were statistically significant (P <0.001). There was no statistically significant difference in RUPP when the patients in groups 2 and 3 were stratified into TURP and RP groups. CONCLUSIONS: PS is a simple and accurate technique for objective evaluation of lower sphincter competence. Patients with stress incontinence after prostatectomy have a statistically significant decrease in RUPP compared with continent controls. In combination with cystourethroscopy and filling CMG, PS can be useful in the evaluation of postprostatectomy incontinence.     

The urethral pressure profiles in continent and stress-incontinent women

Simultaneous urethrocystometry, including recording of the urethral pressure profile, was performed in 127 women aged 30 to 69 years; 42 of the women were free from urologic disorders and 85 had stress incontinence of urine. Both groups were subgrouped according to age. The results in the continent and the incontinent women were analyzed separately, in order to disclose any age-related changes. The data within each decade of age were also comparatively analyzed. In the bladder pressure at rest no age-related changes were found, and the readings were similar in the continent and the incontinent women. The maximum urethral pressure fell significantly with rising age in both groups and was significantly reduced in stress incontinence. The urethral closure pressure showed variations similar to those in the maximum urethral pressure. No lower limit of urethral closure pressure that definitely predisposed to stress incontinence could be established. The functional length of the urethra diminished significantly with rising age in the continent, but not in the incontinent women. The absolute length of the urethra did not show such diminution. Both the functional and the absolute urethral length were significantly less in the incontinent than in the continent women in the age groups between 30 and 49 years.     

Power Doppler of the Urethra in Continent or Incontinent, Pre- and Postmenopausal Women

Urethral pressure should exceed bladder pressure, both at rest and on stress, for urinary continence to occur. A decrease in urethral pressure is a major factor explaining the pathogenesis of urinary incontinence. A number of elements, such as smooth and striated periurethral muscles, and connective, vascular and elastic tissues, contribute to urethral pressure. The periurethral vessels are influenced by hormonal changes during the menstrual cycle, during pregnancy and postmenopause. We studied the periurethral vessels in 97 women, 57 of whom were incontinent and 40 continent, using power color Doppler velocimetry. The number of periurethral vessels, systolic peak, minimum diastolic values, pulsatility and resistance indexes, as well as systolic–diastolic ratio, were assessed. Statistically significant differences were found between incontinent women in the premenopausal period and those in the postmenopausal period, regarding the number of periurethral vessels, systolic peak, minimum diastolic values, pulsatility and resistance indexes.     

Two-stage transperineal management of posterior urethral strictures or bladder neck contractures associated with urinary incontinence after prostate surgery and endoscopic treatment failures

OBJECTIVES: The treatment of posterior urethral strictures or bladder neck contracture associated with severe urinary incontinence after prostate surgery and failure of endoscopic treatments is controversial. We report our experience with a transperineal approach in two steps: end-to-end urethroplasty/anastomosis and subsequent artificial urinary sphincter implantation. METHODS: Between September 2001 and January 2005, we observed six patients (58-68 yr old), with a combination of severe urinary incontinence and posterior urethral stricture with anastomotic bladder neck contracture after prostate surgery. In all cases, repeated endoscopic treatments of the strictures failed. The patients underwent transperineal end-to-end urethroplasty or anastomosis followed by transperineal artificial urinary sphincter placement after 6 mo. RESULTS: After the first surgical step, all patients were completely incontinent with absence of urethral strictures and complete anastomotic healing in all cases. Therefore, all patients underwent artificial urinary sphincter insertion. After a mean follow-up of 38 mo (range: 18-57 mo), five patients are continent with no postvoid residual urine and a perfectly functioning device. One artificial urinary sphincter was removed due to urethral erosion. CONCLUSIONS: In patients with posterior urethral strictures or bladder neck contractures associated with severe urinary incontinence, an artificial urinary sphincter implantation as a second step allows verification of the outcome of a previous end-to-end urethroplasty or anastomosis and utilizes a dedicated operative field to reduce the risks of prosthesis implants.     

The etiology of urinary retention after surgery for genuine stress incontinence

Transient postoperative urinary retention after stress incontinence surgery is common, and there is no widely accepted method of hastening the return to normal voiding. The etiology of this retention is poorly understood. Failure of the relaxation of the striated external urethral sphincter has been proposed as an etiologic agent, but has not been documented. Ten patients about to undergo a Burch colposuspension or sub-urethral sling, who demonstrated normal preoperative voiding, were recruited to a study of postoperative retention. Hook-wire electromyographic (EMG)probes were placed into the external urethral sphincter while the patients were under anesthesia, and a suprapubic catheter was placed. We performed instrumented voiding trials 1 or 2 days after surgery while continuously recording urethral EMG and intravesical pressure. Two patients demonstrated normal voiding. Two patients were able to void but demonstrated no EMG silencing. Six patients were unable to void and demonstrated persistent EMG activity. Four of these demonstrated no detrusor contraction, whereas two demonstrated detrusor contractions. All patients resumed normal voiding by clinical parameters within 14 days of surgery. Our study supports other research that suggests that failure of relaxation of the striated urethral sphincter contributes to postoperative urinary retention.     

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.     

The effect of catheter diameter on the urethral cough pressure profile of continent and incontinent patients

The importance of catheter diameter in causing inaccurate urethral pressure profile recordings was assessed with the aid of a special, dual diameter catheter. Cough pressure profiles obtained in premenopausal and postmenopausal incontinent patients were compared with control groups. The urethral functional length (FL) and pressure transmission ratio (PTR) did not change. The maximal urethral closing pressure (MUCP) decreased with the smaller catheter only in incontinent patients. Similarly, a decreased urethral surface at rest (USR) was observed for incontinent groups. Continent patients showed no modification of MUCP or USR with change in catheter diameter. The occlusive effect of the catheter was high (21 cmH₂O) in incontinent patients and less in continent patients (5 cmH₂O). The part played by the occlusive effect of the catheter may therefore be evaluated and considered an element explaining artificially high MUCP that do not reflect clinical reality in certain patients. This occurs most often in incontinent patients due to curvature of the catheter during coughing.     

Functional conditions of micturition induced by selective sacral anterior root stimulation: experimental results in a canine animal model

Electrical stimulation of the sacral anterior roots using conventional rectangular current pulses results in a simultaneous contraction of the urinary bladder and the striated urethral sphincter. Using a tripolar nerve cuff electrode with quasitrapezoidal current pulses and appropriate stimulation parameters, hyperpolarization of the nerve-fiber cell membrane under the anode of the stimulating electrode can reversibly arrest action potential propagation in large myelinated nerve fibers, innervating the striated urethral sphincter, while leaving action potential propagation unaffected in small non-myelinated nerve fibers innervating the urinary bladder smooth muscle (anodal arrest). Using this technique in 19 female mongrel dogs, we studied the effect of bladder filling, level of anesthesia, and sacral deafferentation on bladder pressure, urethral pressure, and urinary flow. Effective micturition could be induced only after complete dorsal rhizotomy, abolishing reflex contraction of the striated urethral sphincter, when blocking quasitrapezoidal current pulses were used for stimulation. Stimulation with rectangular current pulses directly induced a rise in distal urethral pressure, preventing micturition during stimulation.     

Urodynamic and ultrasound characteristics of incontinence after radical hysterectomy

AIMS: To test whether symptoms of urinary incontinence after radical hysterectomy could be objectified with urodynamics and ultrasound. METHODS: This case-control study comprised 100 women who underwent radical hysterectomy for cervical cancer without post-operative radiotherapy. Fifty women reporting urinary incontinence were matched with 50 women reporting continence. All women were assessed with ultrasound of the bladder neck movements and urodynamics. RESULTS: No differences were found in ultrasound or urodynamic findings regarding mobility of the bladder neck, maximal detrusor pressure, post-voiding residual urine, flow of urine, or bladder capacity. A significant reduction in urethral pressure at rest and at contraction among the incontinent women was, however, demonstrated. Among urge-incontinent women, urethral pressure at rest was significantly lower than among continent and stress-incontinent women, respectively. Stress-incontinent women had significantly lower urethral pressure at contraction than did urge-incontinent and continent women. CONCLUSIONS: No differences in urodynamic or ultrasound findings were observed between the two groups, except for an overall difference in the intraurethral pressure. A decrease in the urethral pressure could contribute to the characterization of incontinence after radical hysterectomy, indicating that the urethral sphincter mechanism plays a role in the pathophysiology. In this study design, the mobility of the bladder neck did not play any role.     

Analysis of risk factors for urinary incontinence after radical prostatectomy

INTRODUCTION: Our aim was to identify the independent risk factors associated with urinary incontinence after radical retropubic prostatectomy (RRP). MATERIALS AND METHODS: Using univariate and multivariate analyses, we examined several pre- and perioperative factors. One hundred and sixty-six patients were divided into three groups: patients who were immediately continent after catheter removal (group I), patients who became continent later (group II) and incontinent patients (group III). RESULTS: There were 34 patients (20.5%) in group I, 111 (66.9%) in group II, and 21 (12.6%) in group III. The multivariate analysis between the continent and incontinent patients proved that the postoperatively measured total length of the posterior urethra (strongly associated with length of the sphincter, length of the urethral stump and the presence of anastomotic stricture) was the independent risk factor for permanent incontinence or delayed continence following RRP. The age of patients per se represented a risk factor only for delayed continence, but not for permanent incontinence. CONCLUSIONS: Postoperatively measured shorter posterior urethral length results in an increased risk of urinary incontinence and delays continence after RRP. It seems that older age only delays reaching continence.     

脊髓损伤患者下尿路功能障碍的尿动力学检查

目的提高对神经源性下尿路功能障碍患者的诊断水平,并为针对性选择康复手段提供可靠依据. 方法对220例不同损伤平面和程度的脊髓损伤患者进行尿动力学检查,其中100例患者常规测定膀胱压力容积和尿道压力图,另120例患者采用膀胱-外括约肌压同步连续测定法分别记录膀胱容量为100 ml时的逼尿肌压、反射排尿时的最大逼尿肌压、最大尿道压,并对所得结果进行统计学分析. 结果除圆锥马尾损伤组的最大尿道压(83±38)cm H2O(1 cm H2O=0.098 kPa)和动态逼尿肌压(12±10)cm H2O低于其他各组,其差异有显著意义(t＝2.096～2.656,P<0.05)外,不同损伤组患者膀胱顺应性降低的发生率相似(分别为51.2%,52.4%和50%);同组不同损伤程度患者间各项参数比较差异无显著意义(t＝1.023,P>0.05).120例患者根据膀胱-外括约肌压同步连续测定法记录尿道压曲线发现,其曲线形状大致可分为4型. 结论除圆锥马尾损伤组的最大尿道压和动态逼尿肌压低于其他各组外,其他参数与损伤平面和损伤程度无关.圆锥马尾损伤组多为不完全性损伤,故而逼尿肌括约肌协同失调的发生率较低.尿道压力曲线的表现与外括约肌和尿道周围横纹肌活动有关.     

Assessment of the intrinsic urethral sphincter component function in postprostatectomy urinary incontinence

Postprostatectomy incontinence remains a disabling condition. Sphincter injury, detrusor instability, and decreased bladder compliance have been previously reported as major factors. The aim of this study was to evaluate the urethral sphincter intrinsic component, which may provide passive continence. A urodynamic evaluation was performed in 20 patients undergoing a radical retropubic prostatectomy in the preoperative period and 3 months after surgery. Patients with disabled urinary incontinence underwent a new urodynamic evaluation 6 months later. The urethral pressure profile was measured just before, then 10, 20, and 30 minutes after the injection of 0.5 mg/kg moxisylyte chlorhydrate, an alpha adrenergic blocker. Three different pressure components were defined in urethral sphincter capacity: baseline, adrenergic, and voluntary. A postoperative intrinsic urethral sphincter pressure component was found in 17 patients and its value was under 6 cm H(2)O in five cases of severe incontinence. No significant difference was observed for these patients on urethral profile components 6 months later. In contrast, in cases of significant intrinsic component value, no incontinence was observed in most patients. Passive continence after radical prostatectomy should be a matter of concern and may also explain paradoxical incontinence, despite high voluntary urethral pressure obtained after reeducation. A follow-up evaluation of the intrinsic sphincter component is suggested, by using an alpha receptor blockage test during urodynamic studies in the management of patients with postprostatectomy incontinence.     

Stellenwert der Stammzelltherapie für die Behandlung der Belastungsinkontinenz

Parallel to a fundamental change in the therapeutic approach to managing stress incontinence, an increasing number of patients ask for reconstruction of the outer, striated urethral sphincter as therapy for urinary stress incontinence. Regenerative medicine is starting to offer solutions using stem cells as a part of oncological therapy or in reconstructive surgery. In addition to the many auspicious experimental approaches, one published study reports the effective therapeutic use of myogenic stem cells in urinary stress incontinent patients. Before this procedure is adopted into general clinical practice, further studies with validated evaluations and a sound legal basis are needed.