Voiding urgency and detrusor contractility in women with overactive bladders

Usefulness of an algebraic fitting of nomograms allowing evaluation detrusor contractility in women

AIMS

Nomograms based on Valentini-Besson-Nelson (VBN) model implying only 3 measurements (filling bladder volume, maximum flow-rate [Q_max] and detrusor pressure at Q_max) were recently developed to evaluate detrusor contractility (k) and urethral obstruction (U) in women. As their algebraic fitting leads to fast evaluations (Excel^® software), our aims were applications to populations of non-neurologic women without and with bladder outlet obstruction (BOO).

METHODS

The software was applied to measurements obtained during pressure flow studies. Hidden hypothesis of nomograms were no significant contribution of abdominal pressure between onset of flow and Q_max and standard nervous excitations until Q_max. Studied populations were 202 women without symptom suggestive of obstruction and 125 women with proven anatomical urethral obstruction who underwent urodynamic study.

RESULTS

For non-obstructed women, a good agreement was found between the values of k and U obtained using nomograms or a complete VBN analysis of the recorded curves. Whatever the obstructive status, there was a good correlation between the value of k and U. Evolution with ageing was similar with higher values of k and U in the BOO group. Curves k(age) and U(age) gave coefficients allowing an age adjustment. The high k value in the detrusor overactive (DO) group was consistent with a similar effect to that of BOO on the detrusor.

CONCLUSION

Evaluation of detrusor contractility (k) and urethral obstruction (U) can be obtained from the point of Q_max during pressure-flow study. Evolution with ageing is similar with (higher values) or without BOO. DO also induces an increased detrusor contractility.

LEVEL OF EVIDENCE

4.

Association of urinary urgency and delay time of micturition in women with overactive bladder

PURPOSE

Accurately measuring urinary urgency is important for diagnosing overactive bladder (OAB) and quantifying improvements in treatment outcome. Various methods have been recommended for evaluating urinary urgency, but these methods assess individual perceptions and preferences. To overcome the subjectivity in measuring urinary urgency, we evaluated the relationship between uroflowmetric parameters and urinary urgency in women with OAB.

METHODS

Consecutive female patients with lower urinary tract symptoms (n=110) were prospectively enrolled in this study between April 2011 and September 2012. Individuals with a history of using medications that are known to affect bladder function were excluded. All enrolled patients completed uroflowmetry with a delayed time to voiding (T2V). After urination was completed, patients were asked whether they experienced any urinary hesitancy or urgency at that time.

RESULTS

The mean patient age was 56.1 years; 70 out of 110 patients reported some degree of urinary urgency. T2V decreased with increased urgency. Several uroflowmetric parameters were observed to have a significant correlation with urinary urgency. T2V had a meaningful correlation coefficient for individuals with urgency, regardless of the voided volume. There was no significant correlation between the presence of urinary hesitancy and T2V.

CONCLUSIONS

We believe that T2V would be a complementary tool for diagnosing and determining the degree of urinary urgency in women with OAB.

Detrusor Underactivity: Clinical Features and Pathogenesis of an Underdiagnosed Geriatric Condition

Urinary incontinence and other lower urinary tract symptoms exert a major influence on the health and independence of frail older people. Detrusor underactivity (DU) is defined as a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span. DU may influence the clinical presentation and impede the therapy of disorders as common and as disparate as detrusor overactivity, urinary retention, and benign prostatic hyperplasia. Urodynamically, nearly two-thirds of incontinent nursing home residents exhibit DU. The clinical diagnosis of DU when present alone or in association with other bladder conditions such as detrusor overactivity (detrusor hyperactivity with impaired contractility (DHIC)) is challenging, because symptoms lack adequate precision. A catheterized and increasingly noninvasive ultrasound-based postvoid residual assessment allows a bedside diagnosis of retention and may suggest the presence of DU in individuals (mostly women) with a low likelihood of bladder outlet obstruction (BOO). Nevertheless, it cannot differentiate primary DU from retention secondary to BOO. The management of individuals with DHIC remains unsatisfactory, because antispasmodic anticholinergic medications may worsen retention, whereas bethanechol does not improve bladder emptying. Human detrusor biopsies reveal axonal degeneration, muscle loss, and fibrosis in DU. Animal studies suggest that multiple risk factors, including retention itself, lack of estrogen, infection, inflammation, and aging, may contribute to DU. Priority areas for future research include efforts to facilitate clinical nonurodynamic diagnosis of probable DU plus translational research designed to address the pathogenesis of this complex multifactorial geriatric syndrome.

The Impact of Detrusor Overactivity on Bladder Function in Younger and Older Women

PURPOSE

We examined the relationship of DO and aging, and bladder function in female volunteers.

MATERIALS AND METHODS

We recruited 85 cognitively competent, fully functional female volunteers who were 22 to 90 years old (median age 54) with and without symptoms suggestive of DO. Comprehensive assessment included a bladder diary, uroflowmetry and videourodynamics. We examined predefined urodynamic and diary variables for associations with DO and age, summarizing results in the 3 subgroups no DO, intermediate DO and clinically relevant DO.

RESULTS

Compared to women without DO those with DO showed a decrease in maximum cystometric capacity (558 vs 448 ml), mean daytime voided volume (260 vs 175 ml) and volume at strong desire to void (363 vs 283 ml) but an increase in maximum isovolumetric pressure (41 vs 64 cm H2O) and maximum detrusor pressure during involuntary contraction (intermediate and relevant DO 22 and 37 cm H2O, respectively). The positive association between increased detrusor contraction strength and DO was present at younger ages but absent in older subjects. Maximum urethral closure pressure and detrusor contraction strength decreased significantly with age.

CONCLUSIONS

From young adulthood to old age DO appears to affect bladder function parameters. It is associated with decreased bladder capacity and increased bladder sensation. Moreover, in younger adults DO is also associated with increased detrusor contraction strength, which is an association not seen in older individuals. This age associated loss of muscle function may be related to sarcopenia, implying that different treatments may be appropriate in older adults.

Urgency degree and bladder contraction velocity: Sequential changes in women with idiopathic detrusor overactivity

AIMS

In patients with idiopathic detrusor overactivity (DO) who showed storage symptoms worsening with time, we checked whether and which urodynamic parameter changes are associated with an increased urgency degree.

MATERIALS AND METHODS

We analyzed retrospectively the urodynamic findings in 54 women -27 with storage symptoms (Group A, mean age 32 +/- 7 years) and 27 controls (Group B, mean age 30 +/- 9 years). These latter had a history of recurrent UTIs (urinary tract infections), but when seen by us had no UTI, DO, lower urinary tract symptoms, or any other pathological finding. Group A had a first urodynamic examination when first referred (time 1) and were re-assessed a mean of 16 months later (time 2) for worsened storage symptoms.

RESULTS

In Group A, an idiopathic DO was shown at both times 1 and 2; urgency of voiding could be delayed during cystometry for >or=2 min (= moderate urgency) at time 1 and for <2 min (= severe urgency) at time 2; detrusor contraction strength or contractility proved higher than in Group B (P < 0.001) and increased from time 1 to time 2 (P < 0.001), detrusor shortening velocity being always the major component of the higher contractility levels.

CONCLUSIONS

A DO-related increase in bladder contractility may have been further enhanced by severe urgency through a positive feedback mechanism. The urgency degree proved closely associated in DO patients with the level of detrusor shortening velocity rather than with detrusor pressure.

Natural history of detrusor contractility--minimum ten-year urodynamic follow-up in men with bladder outlet obstruction and those with detrusor

OBJECTIVE

To check the long-term effect, in male patients, of treated and untreated bladder outlet obstruction (BOO) on detrusor contractility and to explore the relationship between ageing and detrusor underactivity (DUA).

MATERIAL AND METHODS

Men investigated at the urodynamic department of Southmead Hospital in Bristol between 1972 and 1986 were traced and three groups were invited for repeat pressure-flow urodynamic studies (PFS). The first two groups included patients over 40 years old, with untreated or surgically treated BOO, and the third group had patients with DUA from all age groups.

RESULTS

196 patients (with a minimum 10 year gap from the first assessment) agreed to have repeat PFS. There was no statistically significant change in bladder contractility index (BCI) in patients with BOO treated by transurethral resection of the prostate (TURP) (mean difference in BCI was 0.01, 95% confidence interval -0.07 to 0.09, n=114). There was also no significant difference in BCI in untreated patients with BOO (p=0.10, n=53). The follow-up BCI was higher in untreated patients than in the surgically treated group. The BCI in patients with DUA did not change significantly after a minimum of 10 years' follow-up.

CONCLUSIONS

There is no evidence to suggest that detrusor contractility declines with long-term BOO. Relieving the obstruction surgically does not improve the contractility. This is important when considering and counselling for TURP. Underactive detrusors remain underactive, but do not get worse with time, which could indicate that this is not an ageing process per se and may even have a congenital basis.

Urgency of micturition and detrusor contractility in men with prostatic obstruction and overactive bladders

AIMS

In men with prostatic obstruction and detrusor overactivity (DO), to ascertain whether urgency of micturition affects bladder contractility.

MATERIALS AND METHODS

We urodynamically assessed five groups of 20 men each who had bladder outflow obstruction (BOO) from benign prostatic enlargement-Groups 1 (with no DO and no urgency), 2 (with DO and no urgency), 3A (with DO and moderate urgency), 3B (with DO and severe urgency), and 4 (with DO, severe urgency and chronic ischemic cerebral lesions). Urgency was graded as moderate or severe by the ability to avert an urgent void at cystometry for > or =2 or <2 min, respectively. BOO was assessed by the "Abrams-Griffiths number" (AG) and bladder contractility by the parameters PIP and WF(max).

RESULTS

AG did not differ significantly in Groups 2, 3A, and 3B, proved higher in such groups than in Group 1, and was nearly the same in Groups 1 and 4. PIP and WF(max) were significantly higher in Groups 2, 3A, and 3B than in Groups 1 and 4, had the highest levels in Group 3B, and did not differ significantly in Groups 1-4 and 2-3A.

CONCLUSIONS

In DO patients with prostatic obstruction there seems to be a DO-related facilitation of bladder contractility. In the same patients, severe urgency of micturition might over-amplify (i.e., enhance a DO-related facilitation of) bladder contractility, provided there are no neurogenic (chronic ischemic cerebral) lesions.

Urgency: The cornerstone symptom of overactive bladder

Urgency, defined as the compelling feeling of impending incontinence that is difficult to defer, is the cornerstone symptom of overactive bladder. Unfortunately, controversy continues to surround this term and its definition, a fact that has constrained the performance of clinical research in this field. It is important to note that the definition assumes an abnormal sensation that is distinguishable from the normal feeling of "urge to void," which occurs during a normal bladder-filling cycle. The cause of urgency is not fully understood and may vary from patient to patient. Urgency may be controlled by central nervous system mechanisms, lower urinary tract mechanisms, including detrusor myogenic functions (ie, overt detrusor contractions, micromotions, myofibroblast abnormalities), or afferent neural factors. Recently, a number of articles that attempt to quantify urgency have appeared in the literature. Attempts to measure urgency are confounded by difficulties in understanding its definition, the context of normal urge to void, and the power of suggestion in most clinical environments.

Mechanisms of Disease: central nervous system involvement in overactive bladder syndrome

The pathophysiology of overactive bladder syndrome (OABS) and detrusor overactivity (DO) is complex and involves both peripheral and central nervous system (CNS) factors. Central in OABS is urgency, the pathophysiology of which is unknown. Increased afferent activity, decreased capacity to process afferent information, decreased suprapontine inhibition, and increased sensitivity to contraction-mediating transmitters are all potential causes of DO and OABS. Because both urgency and initiation of the micturition reflex depend on afferent input from the lower urinary tract, it seems logical that in the search for new therapies for DO/OABS, afferent functions and central control of afferent functions are targets of interest. Voiding and storage reflexes involve several transmitters and transmitter systems that could be targets for the development of drugs that control DO/OABS. Perturbations of these systems are found in CNS disorders associated with DO/OAB, such as stroke, Parkinson's disease, spinal cord injury and multiple sclerosis. This short overview focuses on the afferent pathways and on how the transmitter systems that control micturition can be perturbed by disease to give rise to DO/OABS.

DETRUSOR OVERACTIVITY. DOES IT REPRESENT A DIFFERENCE IF PATIENTS FEEL THE INVOLUNTARY CONTRACTIONS?

PURPOSE

We evaluated the differences between patients with overactive bladder (OAB) who felt involuntary detrusor contractions during cystometry (detrusor overactivity [DO]) and those who did not feel them.

MATERIALS AND METHODS

We prospectively studied 45 patients with symptoms of nonneurogenic, nonobstructed overactive bladder and with DO on cystometry. All patients underwent videourodynamics, the ice water test and electrical perception threshold determination. Continence, urodynamic parameters, data from specific sensory evaluation and outcome of drug treatment were examined.

RESULTS

Almost half of our patients did feel the contractions of DO and half did not. The groups differed significantly. Those without DO sensation were more frequently incontinent, had more involuntary detrusor contractions and these occurred earlier during bladder filling. They had involuntary start of voiding more frequently, more pathological sensation of bladder filling and lower electrical sensory thresholds. The results of drug treatment were better in the group who felt DO.

CONCLUSIONS

Contractions of DO are felt by some of the patients and they differ from those patients who do not feel such contractions. It is likely that this finding reflects the existence of different OAB conditions with a different neuropathological cause and a different treatment outcome. Therefore, we suggest that specific tests for the evaluation of sensation in the lower urinary tract should be part of the diagnosis of patients with DO and symptoms of OAB.

Randomized, double-blind placebo- and tolterodine-controlled trial of the once-daily antimuscarinic agent solifenacin in patients with symptomatic overactive bladder

OBJECTIVE

To assess in a phase 3a trial the efficacy of solifenacin succinate, a once-daily oral antimuscarinic agent in development at 5-mg and 10-mg dosage strengths, for the treatment of overactive bladder (OAB) (Yamanouchi Pharmaceutical Co. Ltd, Tokyo, Japan) compared with placebo in patients with symptoms of OAB, i.e. urgency, incontinence, and frequency, with additional objectives being to assess the safety and tolerability of solifenacin and to compare the efficacy and safety of solifenacin with tolterodine 2 mg twice daily.

PATIENTS AND METHODS

The study was an international, multicentre, randomized, double-blind, tolterodine- and placebo-controlled trial conducted at 98 centres. Adult patients with symptomatic OAB for > or = 3 months were eligible; after a single-blind 2-week placebo run-in period patients were randomized equally to a 12-week double-blind treatment with either tolterodine 2 mg twice daily, placebo, solifenacin 5 mg or 10 mg once daily. Efficacy variables included change from baseline in the mean number of urgency, incontinence and urge incontinence episodes, and change from baseline in voids/24 h and mean volume voided/void.

RESULTS

In all, 1281 patients were enrolled, 1081 randomized and 1077 treated; 1033 were evaluated for efficacy. Compared with placebo, the change from baseline (-1.41, -32.7%) in the mean number of urgency episodes per 24 h was statistically significantly lower with solifenacin 5 mg (-2.85, -51.9%) and 10 mg (-3.07, -54.7%; both P < 0.001), but not with tolterodine (-2.05, -37.9%; P = 0.0511). There was a statistically insignificant decrease in episodes of incontinence with tolterodine (-1.14; P = 0.1122) but a significant decrease in patients treated with solifenacin 5 (-1.42; P = 0.008) and 10 mg (-1.45; P = 0.0038). Compared with placebo (-1.20, -8.1%) the mean number of voids/24 h was significantly lower in patients receiving tolterodine (-1.88, -15%; P = 0.0145), solifenacin 5 (-2.19, -17%) and 10 mg (-2.61, -20%; both P < 0.001). The mean volume voided/void was also significantly higher with all three active treatments (P < 0.001). Solifenacin was well tolerated; compared with placebo (4.9%), dry mouth (the most common side-effect), mostly mild, was reported in 18.6% of patients receiving tolterodine, 14.0% receiving 5 mg and 21.3% receiving 10 mg solifenacin.

CONCLUSION

Solifenacin 5 and 10 mg once daily improved urgency and other symptoms of OAB, and was associated with an acceptable level of anticholinergic side-effects. Solifenacin demonstrated significantly favourable efficacy to side-effect ratio in treating symptomatic OAB.

Urgency of voiding and abdominal pressure transmission in women with mixed urinary incontinence

AIMS

To ascertain whether abdominal pressure transmission (a.p.t.) to the urethra would be affected by urgency of voiding in women with mixed urinary incontinence.

METHODS

We urodynamically assessed 80 consecutive women. Group 1 (n = 40), with stress incontinence, had stable bladders and no urgency. Group 2 (n = 40), with mixed (stress + urge) incontinence and overactive bladders, were split into Groups 2A (n = 20) and 2B (n = 20) according to the delay time of urgent void at cystometry (CMG) equating at least 2 min (taken as an index of moderate urgency) or, respectively, less than 2 min (taken as an index of severe urgency). Nonparametric statistics checked for significant differences in a.p.t. and in pelvic floor (peri-urethral) muscle strength level. We defined a.p.t. at stress (cough) urethral pressure profilometry (UPP) by the pressure transmission ratio (PTR). Pelvic floor muscle strength was defined at "holding" UPP by the maximum urethral pressure developed during attempts "to hold urine" (hMUP).

RESULTS

PTR was reduced in all women, but PTR (and hMUP) proved relatively higher in Group 2, though nonsignificantly different values of PTR (and hMUP) were seen in Groups 2B and 1.

CONCLUSIONS

Transmission of abdominal pressure to the urethra was reduced in all of the incontinent women. The mixed incontinence group, however, had a relatively less reduced (active component of) a.p.t., most likely dependent on a greater pelvic floor (peri-urethral) muscle strength level secondary to frequent contractions in response to urgency. Yet, of the same mixed incontinence patients, those with the most severe urgency degrees had relatively low pelvic floor (peri-urethral) muscle strength levels (eventually resulting from muscle fatigue? or primarily due to peri-urethral tissue atrophy?), which prevented (the active component of) a.p.t. from increasing.