bluuebunny/crossref_metadata_2025 huggingface dataset:
Pressure/flow studies in elderly men without voiding problems: Estimation of the urethral pressure/flow relation and urethral elasticity
Authors: Spångberg Anders , Teriö Heikki , Ask Per
Published: March 2007

The flow in the urethra is controlled by an elastic constriction, the flow‐controlling zone. The distensibility of this zone is described by the pressure/area relation, which gives the static pressure as a function of the cross‐sectional area at the flow‐controlling zone. The pressure/area relation can be calculated from the pressure/flow relation, which is estimated from the pressure/flow plot obtained at a urodynamic examination. In this study the urethral pressure/flow and pressure/area relations were estimated for 21 randomly selected men (62–75 years old) without voiding problems.

Nineteen of 21 persons in this group had pressure/flow relations with a low slope. This corresponds to a low slope in the pressure/area relation indicating high distensibility of the flow‐controlling zone, which for 18 persons was estimated to be distended to areas larger than 10 mm2 during micturition. Twenty persons had a minimal urethral opening pressure below 55 cm H2O. The estimated pressure/area relation was linear in 59% of the micturitions, indicating that the flow‐controlling zone could have been distended to a larger cross‐sectional area, if the bladder had achieved a higher pressure. The 10th–90th percentiles for maximum flow and detrusor pressure at maximum flow were 7.2–24.3 ml/s and 24–76 cm H2O, respectively. Four persons had low flow and low pressure, indicating diminished detrusor contractility with age. Twenty‐four percent of the persons had unstable bladder contractions with a pressure rise < 15cm H2O and 19% with a pressure rise < 15cm H2O.
Adult female intra‐ and peri‐urethral sphincter‐electromyographic study
Authors: Chantraine A. , Leval J. De , Depireux P.
Published: March 2007

Twenty‐two healthy women aged 22–64 years with normal micturition volunteered for electromyographic (EMG) study of their striated urethral sphincters. The EMG findings of the peri‐urethral and intra‐urethral sphincter with an empty bladder showed at rest mean amplitude of 167.23 ± 23.3 μV and 89.7 ± 7 μV and mean duration of 4.9 ± 0.57 msec and 5.6 ± 0.19 msec respectively. During maximal voluntary contraction an interference pattern was obtained with an amplitude increased to twice normal. During bladder filling, studies on seven of these subjects showed that the peri‐urethral and intra‐urethral sphincters behaved differently. As filling proceeded the intra‐urethral sphincter showed no change at all, whereas the peri‐urethral sphincter displayed a progressive increase of the motor unit recruitment without any other significant modification.
Microcomputer‐Based incontinence data management system for elderly inpatients
Authors: O'Donnell Pat D.
Published: March 2007

The quantitative measurement of urinary incontinence in elderly inpatients presents a complex problem of clinical assessment. The characteristics of incontinence data in chronic care patients include incontinence episodes. volume of urine loss, and time of events. The objective of an incontinence data management system was the integration of incontinence characteristics with the information sequence from the data source to develop an interactive filing system that will allow useful output presentations of data. A microcomputer‐based incontinence data management system is described which was developed from commercially available software as a specific software application for incontinence information management in elderly chronic care inpatients. Data management requirements of data recording, quality control, report formats, and statistical analysis interfacing can be accomplished using microcomputer products.
Response of the whole bladder‐urethra model (rabbit) to autonomic drugs
Authors: Chun Alexa L. , Wein Alan J. , Gill Harcharan S. , Levin Robert M.
Published: March 2007

To investigate the function of the bladder‐urethra as a continuous unit we set up an in vitro whole bladder‐urethra model (rabbit). We were able to measure the intravesical pressure at which saline infused into the bladder emptied via the urethra (“opening pressure”). Methoxamine added to the bath caused a significant increase in opening pressure, whereas phentolamine caused a significant decrease in opening pressure compared to controls. Atropine had no effect on opening pressure in the absence or presence of methoxamine. Thus, it appears that the in vitro bladder‐urethra unit has intrinsic alpha‐adrenergic tone that is of sufficient force to maintain an intravesical pressure of 7.0 cm H2O, and that this tone is not influenced by antagonism with the anticholinergic agent atropine.
Relaxation of intestinal bladders by intravesical oxybutynin chloride
Authors: Mohler James L.
Published: March 2007

Incontinence is a frequent complication of continent urinary diversions and neurogenic bladder augmentations constructed from intestinal segments. Oxybutynin chloride was delivered intravesically and orally to six beagles 9 months after bladders were replaced by tubularized ileum (in three dogs) or sigmorectum (in three dogs). Intravesical oxybutynin produced greater bladder relaxation by urodynamic criteria. Measured oxybutynin chloride concentrations suggested that high tissue levels were achieved at low systemic levels. In two human patients with ileocecal urinary diversions, intravesical oxybutynin chloride decreased bladder pressure and decreased the number and magnitude of superimposed contractions. Intravesical application of oxybutynin chloride may produce local drug levels unachievable by oral administration and may better treat incontinence in patients who intermittently catheterize intestinal bladders or intestinally augmented neurogenic bladders.
Interstitial cystitis: Clinical manifestations and diagnostic criteria in over 200 cases
Authors: Parsons C. Lowell
Published: March 2007

Over 200 patients were evaluated for the syndrome of interstitial cystitis. The average patient was found to void 16 times per day with an average volume of 106 ml, nocturia averaged 4–6 times (but 18% of patients voided < 2 times per night) and symptoms were present at least 1 year. Eight‐five percent of the patients were female and 83% had pain. The median age was 44.

Cystoscopic changes revealed no carcinoma or carcinoma in situ in 175 patients studied with an average capacity under anesthesia of 561 ml (measured in 175 patients). Only 8% of the patients had ulcers and 89% had glomerulations. Seventy‐five patients had cystometrograms demonstrating an average maximum capacity of 220 ml and an increased sensory urgency in 95% of patients (< 100 ml volume stimulating urgency was considered abnormal).

The 90% confidence limit for findings in this disease showed the average voids per day was at least 10, with an average voided volume of < 160 ml, nocturia at least 1–2 per night, duration of symptoms over 1 year, anesthetic bladder capacity of < 850 ml.
Vesico‐anal influences in healthy intact humans: Quantificated by responses in the external anal sphincter following transcranial cortical stimulation
Authors: Hansen Michael V. , Holmgren Helen , Sp∠berg Anders , Warycha Andrej
Published: March 2007

EMG responses in the external anal sphincter (EAS), the rectus abdominis muscle (RA), and the anterior tibial muscle (TA) were recorded following single magnetic transcranial cortical stimulations (TCCS) in seven healthy volunteers. The responses in the EAS differed from the responses in the other muscles. They had comparatively long durations ranging from 1 to 2 seconds, no inhibitory periods were observed, and there was no tendency for habituation to occur following a limited number of stimuli. The responses recorded in the EAS were used as test responses in order to evaluate the excitability changes in the EAS motoneurons occurring during bladder filling. Cystometries with filling rates of 15, 50 and 200 ml/min were done. During these cystometries TCCS were applied repeatedly, with constant strength, after each 50 ml of filling up to bladder capacity. The responses following TCCS changed in a highly reproducible way during bladder filling. After 100–200 ml of filling, the responses had longer latencies, diminished sizes, and shorter durations. When the filling reached a level 50–150 ml below capacity, the responses in most subjects again became greater and the latencies shorter. The changes were believed to be physiological. It was concluded that the EAS motoneurons are under both inhibitory and facilitatory influence during bladder filling in intact healthy humans. Facilitatory influences are often observed when the bladder is filled close to capacity. At lower bladder volumes the observed influence is always inhibitory. A decrease in the EMG activity of the EAS during filling cystometry should consequently not be regarded as a pathological response.
Trypan blue as an indicator of urothelial integrity
Authors: Levin Robert M. , Wein Alan J. , Whitmore Kristene , Monson Frederick C. , Mc Kenna Beth A. W. , Ruggieri Michael R.
Published: March 2007

Defects in the urinary bladder urothelium may be an etiological factor in conditions such as recurrent urinary tract infection and interstitial cystitis. Initial studies have demonstrated that the colloidal dye trypan blue can be used as a marker for defects in the integrity of the mucosal epithelium. Male white New Zealand rabbits were separated into 4 groups: Control, in vivo overdistension (via saline infusion), intravesical acetone (20 ml 50% for 1 minute), and intravesical 50% DMSO (20 ml “RIMSO‐50” for 30 minutes). Both intravesical instillations were followed by 3–20 ml saline washes. Immediately following acetone or DMSO, 20 ml 1% trypan blue in saline was instilled and left in the bladder for up to 1 hour. After overdistension, 1% trypan blue in saline was infused into the bladder at the same rate until the volume reached that previously defined as the overdistension volume. Control bladders were rinsed with 20 ml saline, twice, before being filled with 20 ml of the trypan blue solution.

There was no evidence of trypan blue's staining of tissues in any of the control bladders. After DMSO treatment, there was usually only slight staining of the bladder surface urothelium and subjacent connective tissues. After acetone treatment, microscopic examination of bladder wall showed that nuclei were stained in all tissues of the wall (e.g., urothelium, connective tissue and smooth muscle). After acute frank overdistension, the bladder wall was deep blue throughout, very similar to the acetone‐treated bladder. Microscopic analysis demonstrated that the smooth muscle elements were the most heavily stained.

In summary 1) trypan blue does not penetrate the normal bladder mucosa, nor is any dye absorbed into the blood stream. 2) Frank overdistension of the bladder defeats the physical integrity of the urothelium as evidenced by penetration of the dye into the submucosal tissue, the peritoneal cavity, and bloodstream. 3) Where DMSO penetrates the urothelium itself, it appears to leave no permanent route by which other molecules can traverse the urothelium after it is removed. 4) Only after the integrity of the urothelial surface is disturbed are the cells of the urothelium susceptible to staining.
Simultaneous urethral pressure profilometry using a microtip transducer catheter in the bitch: Effects of bitch position and transducer orientation
Authors: Holt P. E. , Gibbs C. , Wathes C. M.
Published: March 2007

Simultaneous urethral pressure profilometry using a microtip transducer catheter was perfonned in 14 bitches to determnine the effects of the position of the animal and the transducer orientation.

The technique was carried out in three positions of the bitch (right lateral, dorsal, and left lateral recumbency) and four orientations of the transducers (Diorsal, right, ventral, and left).

Both functional profile length and maximum urethral closure pressure were significantly affected by the orientation of the transducer relative to the position of the bitch.

The optimum position of the bitch and orientation of the transducers were detennined by evaluating the proportion of profiles from which measurements could not be made, the diagnostic value of profiles, and the Proportion of artefacts in functional profile length. It was concluded that the bitch should be positioned in right lateral recumbency with the transducers orientated dorsally as these positions result in the highest proportion of diagnostic and measurable profiles and the lowest proportion of artefacts in functional profile length.
Time constants in force development and force recovery in smooth muscle
Authors: Van Mastrigt R.
Published: March 2007

The isometric force development of pig urinary bladder smooth muscle strips in response to electrical stimulation and the force recovery following quick release of fully activated strips were characterized by a set of three time constants. The slowest time constant in the order of 2.2 s characterizes the intracellular calcium release in the excitation‐contraction coupling process. The second time constant was in the order of 0.45 s and could be related to cross‐bridge cycling, whereas the fastest time constant in the order of 0.032 s was ascribed to passive viscoelastic processes in the cross‐bridges.
Impact of changes in posture and bladder filling on the mechanical properties of the urethra in healthy and stress‐incontinent females
Authors: Lose Gunnar
Published: March 2007

A pressure/cross‐sectional area probe was used to examine the impact of changes in posture and bladder filling on the mechanical properties of the urethra in 29 healthy females and in 28 patients with genuine stress incontinence (GSI). Measurements were performed at the bladder neck, in the high‐pressure zone, and distally in the urethra.

When changing posture from supine to standing position the urethral pressure at the bladder neck and midurethrally increased statistically significantly (P>0.01) in both groups. The urethral pressure increase was most pronounced in the midurethra which indicates that active muscle contraction is involved. Maximum urethral closure pressure was unchanged in the control group while it decreased statistically significantly (P>0.01) in the GSI group. Urethral elastance increased midurethrally in healthy women while it decreased in GSI women in the upright posture. Although these changes were not statistically significant, elastance was statistically significantly higher midurethrally in the erect position in the control group. These findings indicate impaired striated muscle function in or around the urethra in GSI women.

Filling the bladder to 50% of the functional capacity did not change any urethral parameter in the two groups of women. The wide divergency in previously reported results is discussed.
Pelvic floor muscle exercise for the treatment of female stress urinary incontinence: I. Reliability of vaginal pressure measurements of pelvic floor muscle strength
Authors: Bø Kari , Kvarstein Bernt , Hagen Rolf , Larsen Stig
Published: March 2007

The reliability of measurements of pelvic floor muscle strength using a vaginal balloon catheter connected to a pressure transducer was tested in 28 healthy women, mean age 32.3 years (21–50).

Fourteen women (group 1) performed three pelvic floor muscle contractions in three series with reinstallation of the balloon catheter to the same vaginal position between each series. Additionally, retest was done after a period of 2 weeks. Reproducibility of the results was tested in another similar group of 14 women (group 2) who did a 1 day test.

In the first group the maximum contraction value (resting pressure not included) varied from 5 to 40 cm H2O. However, the median difference value of the three series tested on two different days was only 3, 1, and 1 cm H2O, respectively. The two groups of women demonstrated similar values of vaginal pressure measurements. Thus, a balloon with a given vaginal position for measurements of pelvic floor muscle strength gives reliable pressure recordings.
Pelvic floor muscle exercise for the treatment of female stress urinary incontinence: III. Effects of two different degrees of pelvic floor muscle exercises
Authors: Bø Kari , Hagen Rolf H. , Kvarstein Bernt , Jørgensen Jan , Larsen Stig , Burgio Kathryn L.
Published: March 2007

Fifty‐two women, mean age 45.9 years (24–64) with clinically and urodynamically proven stress urinary incontinence (SUI) were randomly assigned to one of two different pelvic floor muscle (PFM) exercise groups. Both groups performed 8–12 maximal PFM contractions 3 times a day for 6 months. In addition one group exercised with an instructor intensively 45 min once a week performing long‐lasting contractions with the supplement of 3–4 fast contractions at the end of each long‐lasting contraction.

Initially and after 6 months an examination was performed comprising history, urinary leakage index, pad test, maximum urethral closure pressure, functional urethral profile length, and recording of vaginal pressure during PFM contractions. The latter was performed monthly.

After the treatment 60% of the intensive exercise (IE) group and 17.3% of the home exercise (HE) group reported to be continent or almost continent (P < .01). Only the IE group demonstrated significant reduction in urine loss; from mean 27 g to 7.1 g (P < .01) and improvement in maximum resting urethral closure pressure (mean improvement 4.6 cm H2O. P = .02). PFM strength improved with mean 15.5 cm H2O (P < .01) in the IE group while the HE group improved with 7.4 cm H2O (P < .01).

It is concluded that the results of PFM exercise for female SUI is highly dependent upon the degree and duration of treatment and frequent supervision by the therapist.
Changes in bladder function following a surgical alteration in outflow resistance
Authors: Pope A. J. , Shaw P. J. R. , Coptcoat M. J. , Worth P. H. L.
Published: March 2007

The changes in bladder function occurring after a surgical alteration in bladder outflow resistance were studied in 20 males undergoing transurethral prostatectomy (TURP) and in 20 females undergoing an endoscopic bladder neck suspension (EBNS). Serial cystometrograms (CMG) were performed before operation, and on alternate days after spontaneous micturition was re‐established, for 5 days in the males and for 21 days in the females. CMGs were repeated at 3 months and 1 year after operation.

After TURP voiding pressures (Pdet) fell rapidly from a mean of 118 cm H2O before operation to 57 cm H2O at 5 days, with an increase in flow rate during this time from 10.5 ml/s to 24 ml/s. Detrusor instability that had been present in 14 patients resolved within 2 days in 12. There was no further significant urodynamic change over the 1‐year study period.

After EBNS, there was an early rise in voiding pressure (Pdet rose from 26 cm H2O before operation to 42 cm H2O at 3 days). This continued to increase up to 21 days particularly in those patients with initial large residuals. Three patients developed detrusor instability. Flow rates were greatly reduced at first (27 ml/s before operation and 13 ml/s at 3 days), and gradually increased in line with voiding pressures, yet were still diminished 1 year after operation.

The urodynamic changes following a reduction in bladder outflow resistance by TURP are immediate and sustained and unlikely to be the result of structural changes within the bladder wall. EBNS produces an increase in outflow resistance and it can be several weeks before balanced voiding is achieved, with significantly increased detrusor pressures needed to achieve complete bladder emptying at a reduced flow rate.
Psychophysical functions of the sensation evoked by electrical stimulation of the posterior urethra
Authors: Hansen Michael V.
Published: March 2007

Following electrical stimulation of the posterior urethra, visceral afferent nerves are excited that transmit sensory information perceived as an imminent desire to void. In the present study, some basic psychophysical relations involved in the sensations evoked this way were investigated. The results included the following. First, in the temporal integration relation, the relation between the sensory threshold (sT) and the duration of the stimulus (D) followed a power function: sT*DK = m, in which K and m are constants. Second, in 20 healthy subjects, the sensory threshold determined with increasing strength (sTi) and determined with decreasing strength (sTd) were linearly correlated (P≤0.001). The slope of the relations between sTi and sTd decreased with the duration of stimulus. Third, the sTi and sTd were inversely related to the frequency of the stimulus. Fourth, the relation between the mean reaction time (RT) and the stimulus strength (I) followed a significant power function fit after stimulation in the posterior urethra (R = 0.93, P≤0.001): RT = ∂ * I−n, in which ∂ and n are constants. Finally, stimulation of the penile skin either electrically, with vibration or with a cold stimulus, caused a significant increase in the sensory thresholds determined in the posterior urethra. The conclusion of the study was that sensations evoked by electrical stimulation of visceral afferent pathways in the posterior urethra follow psychophysical power functions similar to those of exteroceptive sensory modalities.
Transurethral nervi erigentes stimulation: An experimental study in the dog
Authors: Hashmat A. , Vega A. Luna
Published: March 2007

An erection obtained during external sphincterotomy on a paraplegic patient prompted this experiment in an animal model. Four dogs were anesthetized and a transurethral electrical current was used to stimulate the cavernosus nerves and obtain a penile erection. The erectile response was assessed by measurement of the girth of the glans before and after stimulation. There was an increase of 2 cm in the girth of the glans and the penis became firm and remained erect while being stimulated.

The aim of the experiment was to elucidate another technique to assess the integrity of the nervous pathway for erection. Transurethral stimulation of nervi erigentes may be used also as a tool to investigate erectile dysfunction.

The stimulated erection observed in a paraplegic patient after transurethral electrical stimulation confirms previous observations that the erectile mechanism is maintained in paraplegic patients, with an intact thoracolumbar sympathetic outflow.
Urodynamic changes in women using diaphragms
Authors: Ramahi Alfida J. , Richardson David A.
Published: March 2007

Although the diagphragm is widely used as a method of contraception, little is known as to its effect on urethrovesical function. To evaluate whether the diaphragm, or diaphragm size, influences bladder function, urodynamic studies were performed in nine nulliparous volunteers. Maximum and mean flow rates were significantly decreased with diagphragm use (P>0.02). Urethral resistance was significantly increased with both diaphragm sizes compared to control values (P>0.02). There were no significant changes in urethral functional length, closure pressure, and pressure transmission ratio between the diaphragms and control. Although there were statistically significant differences in urodynamic results, no strong evidence for urethral obstruction was found with diaphgram usage.
Distal urethral compensatory mechanisms in women with an incompetent bladder neck who remain continent, and the effect of the menopause
Authors: Versi Eboo , Cardozo Linda , Studd John , McGuire Edward , Versi E. , Cardozo L. D.
Published: March 2007

Female continence is thought to be maintained at the level of the bladder neck and by the external sphincter. However, many women have an incompetent bladder neck, that is their bladder neck opens under stress. However, they still remain continent, presumably by use of their distal external sphincter. To establish the effect of age and the menopause on this phenomenon, data from 202 climacteric urodynamically normal and continent women were examined. The overall prevalence of videocystourethographically diagnosed bladder neck incompetence in these women was 51 ± 4%. The median age in this group was 50.4 years but the prevalence of bladder neck incompetence in women below 50.4 years was not significantly different from older women (>50.4 years) being 49 ± 5% and 53 ± 5%, respectively. Of the 202 women studied the prevalence of bladder neck incompetence in perimenopausal women was 54 ± 5% and 48 ± 5% in postmenopausal women, there being no statistically significant difference between the two subgroups separated on the basis of their estrogen status. These data do not support the contention that bladder neck integrity is estrogen dependent nor is there any evidence from these data that is it age dependent. To understand how women with bladder neck incompetence maintain continence, 55 of the 202 women also underwent urethral pressure profilometry. Bladder neck incompetence results in a proximal shortening of the stress urethral pressure profile but these women maintained their stress urethral functional length by decreased distal shortening of the stress profile. In other words, they made more use of the distal portion of the urethra. This is achieved by augmentation of their distal transmission pressure ratios.
Ontogeny of bladder compliance
Authors: Zderic Stephen A. , Duckett John W. , Snyder Howard M. , Wein Alan J. , Levin Robert M.
Published: March 2007

Recent advances in technology have allowed for the diagnosis of many urologic abnormalities through the use of antenatal ultrasonography. There is great debate in the pediatric literature as to whether the hydronephrosis which is diagnosed via antenatal ultrasound is always secondary to obstruction, or in certain cases represents a benign dilatation. Benign dilatations are postulated to be secondary to the increased fetal diuresis and a more compliant fetal urinary tract. In this study we present evidence for a gradual decline in bladder compliance with maturation. A summary of our results demonstrates that bladders obtained from 1 day old rabbits are 2 and 3 times more compliant than bladders of 4–8 week old rabbits. Active tension reaches a peak when the muscle is stretched to 150% of its initial resting length. However, 1 day old bladder tissue exhibits a higher active tension in response to field stimulation when compared to the response of bladder tissue obtained from 4 and 8 week old rabbits. In summary, compliance and active tension decrease with maturation.
Parameters of detrusor contractility: I: The effects of electrical stimulation, hysteresis, and bladder volume in an in vitro whole rabbit bladder model
Authors: Kaplan Steven A. , Blaivas Jerry G. , Brown William C. , Levin Robert M.
Published: March 2007

This study represents the first of a five phase project which was designed to develop parameters to assess detrusor contractility and urethral obstruction. The first phase was designed to (1) determine the optimal volume at which to measure various parameters of detrusor contractility and (2) determine the effects of hysteresis on isovolumetric detrusor pressure (Piso). To this end, the bladders of five male white New Zealand rabbits were isolated and placed in a bath chamber. Intravesical pressure and the weight of the voided urine were monitored by a pressure transducer and electronic balance, respectively. Bladder capacity ranged between 41 ml and 53 ml (mean 47 ± 2.34). In the first phase of this experiment, Piso was determined at 1, 2.5, 5, 10, and 20 ml. Piso was always found at a volume of 2.5 ml (20.7 ± 2.86). There was a 13% decrease in Piso at 1 and 5 ml, a 35% decrease at 10 ml, and a 49% decrease at 20 ml. This was significant at P < 0.05.

In the second part of the experiment, the effect of different methods of filling on the magnitude of subsequent isometric contractions was examined. It was found that preceding strain (hysteresis) had no effect on subsequent contractions. In addition, the average Piso for each volume remained the same regardless of the method of filling.

In conclusion, these data suggest that the effect of hysteresis and method of bladder filling on Piso was negligible. In addition, as one would expect from the geometric configuration of the bladder, maximum detrusor pressure occurred at relatively low bladder volumes, i.e., less than 5% capacity. Further research is in progress to determine which parameters are important in delineating and predicting bladder performance.
Impaired bladder contractility in association with detrusor instability: Underestimated occurrence in benign prostatic hyperplasia
Authors: Ghoniem Gamal M.
Published: March 2007

The hyperactive bladder does not always completely empty. The aim of this study was to determine the frequency of detrusor instability and impaired contractility in 45 patients with benign prostatic hyperplasia. The evaluation consisted of uroflowmetry, residual urine determination, cystometrogram (CMG), and micturition study with stop‐flow technique. Detrusor instability is diagnosed urodynamically with the appearance of abnormal contractions either on medium filling CMG and/or on a provocative rapid injection CMG. Impaired bladder contractility was diagnosed by the presence of significant residual urine (≥50% of capacity) and unsustained bladder contraction with no or little detrusor reserve power. Urodynamic evaluation showed that 21 out of 45 patients had detrusor instability. Seven of these patients showed also impaired contractility. The mean residual urine was 380 ml in this subgroup. On micturition studies five of these patients showed low pressure, low uroflow pattern. Stop‐flow technique revealed absence of detrusor reserve power in five patients, while two patients showed little detrusor reserve power. Out of the 24 patients with stable bladders, four showed impaired contractility. Indeed, detrusor instability is not associated exclusively with low residual urine values. The importance of recognizing detrusor instability in combination with poor contractility in patients with benign prostatic hyperplasia is that one can anticipate incomplete bladder emptying even after protstate surgery and consider other forms of therapy. Our approach to this specific problem is presented.
Detrusor behavior in patients with dominant hemispheric strokes
Authors: Badlani Gopal H. , Vohra Sanjeev , Motola Jay A.
Published: March 2007

The urodynamic evaluations of 44 consecutive stroke patients were evaluated retrospectively. The results were evaluated with regards to the location of the cerebrovascular accident. Urodynamic findings could not be characterized by the site of the cerebrovascular injury sustained. In this retrospective study, we were not able to define an influence of a dominant hemispheric stroke upon future bladder function.
Detrusor hyperreflexia and its relationship to posterior bladder neck sensor mechanism in spinal injured patients
Authors: Perkash Inder , Wolfe Vickie
Published: March 2007

This report describes the existence of a sensor mechanism at the posterior bladder neck region which invokes bladder contraction in patients with detrusor hyperreflexia when stimulated mechanically with a transurethral catheter. Studies were monitored through transrectal linear array sonography to precisely localize the site stimulated with the tip of the catheter during urodynamic evaluation. The location of sensor mechanism is just distal to the trigone at the posterior bladder neck region and extends into the posterior urethra for 0.5 to 1 cm into the posterior urethra. Its clinical implications in female urge incontinence seem to agree with the “second sensor” described by Bradley in 1975 (Urology 6:654, 1975). The bladder neck sensor mechanism possibly facilitates normal progressive voiding and seems to exaggerate voiding in the hyperreflexic bladders.
Pressure/flow studies preoperatively and postoperatively in patients with benign prostatic hypertrophy: Estimation of the urethral pressure/flow relation and urethral elasticity
Authors: Spångberg Anders , Teriö Heikki , Ask Per , Engberg Anders , Griffiths Derek
Published: March 2007

Pressure/flow studies were performed in 28 men with benign prostatic hypertrophy. Twenty‐three of the men were also studied postoperatively. Urethral function during micturition was quantified by the urethral pressure/flow relation, pdet = pmo + Lm Qm, where Pdet is detrusor pressure, Pmo is minimal opening pressure. Q is flow rate, and m and Lm are parameters. Using this method to quantify urethral function, three urodynamically different types of obstruction can be defined. In the first of these, Pmo is elevated corresponding to Schäfer's compressive obstruction. The second is a constrictive type of obstruction in which m ≥ 4/3 and Lm is elevated and the third is a low‐compliant type of obstruction in which m ≤ 1 and Lm is elevated. The two latter types of obstruction may be combined with a compressive obstruction.

The preoperative pressure/flow relations were mostly characterized by a very high Pmo, a moderately elevated Lm, and a low m. Thus the majority of patients had a combination of compressive and low‐compliant obstruction. Postoperatively, micturitions were much improved and the pressure/flow relations often had an even lower Pmo than normal, a normal Lm, and a high m.

From the pressure/flow relations, the elasticity of the flow‐controlling zone can be estimated and described by the urethral pressure/area relation, p(A) = pmo + Kn An, where p(A) is the intrinsic urethral pressure, A is the cross‐sectional area of the flow‐controlling zone and Kn and n are parameters describing the distensibility of the flow‐controlling zone. Preoperatively, the flow‐controlling zone had a low distensibility. The shape of the curve suggested that the urethra could have been distended further by higher pressure. Postoperatively, the urethra was distended to larger cross‐sectional areas, but in many cases the shape of the curve suggested that distension was restricted by fibrosis. Median and range values for the model parameters as well as discriminating limits between the preoperative micturitions and micturitions in elderly men without voiding problems are presented.

The exponent m is not perfectly reproducible but tends to be the same if a person performs several micturitions. The residual sum of squares is often increased more than 100% if an exponent m value other than the optimal one is used for curve fitting.

Results when the micturitions were analysed with Schäfer's model and classified using the maximum flow/pressure at maximum flow diagram recommended by the Interenational Continence Society are also shown.
A pressure management system for the neurogenic bladder after spinal cord injury
Authors: McGuire E. J. , Noll F. , Maynard F.
Published: March 2007

One hundred eighteen patients consecutively admitted to a University Rehabilitation Program entered a protocol study of urologic management. Bladder pressures were kept below 30 cms/H2O by urologic treatment. Serial urodynamic, radiographic, bacteriologic, and endoscopic studies were performed at regular intervals. Eighteen patients have been lost to follow‐up; 100 patients were followed for a mean 25.4 months with a range of 6 months to 56 months. There were 105 patients with lesions superior to the sacral segments and 13 patients with low lesions. At discharge 11 patients were voiding normally, 105 were continent on an intermittent catheterization (IC) protocol, and 2 patients used condom catheter drainage following sphincterotomy. Bacterial cultures and urinalysis data showed little or no relationship to clinical outcome, and treatment for 387 weeks by antimicrobial agents was not associated with discernible benefit as opposed to no treatment. Five patients developed bladder calculi, and five developed unilateral epididymitis. Bladder pressure was relatively easy to control following spinal cord injury, a result which suggests that high bladder pressure is not a direct result of the neural injury, but rather an evolutionary change as a result of bladder and urethral interactive dysfunction.
Pathophysiologic subdivision of genuine stress incontinence
Authors: Lose Gunnar , Colstrup Hans
Published: March 2007

A pressure/cross‐sectional‐area probe was used to describe permanently and adjunctively acting urethral closure forces and urethral deformability at the bladder neck and midure‐thrally in 30 females with genuine stress incontinence (GSI). The permanent closure forces were described in terms of urethral pressure and elastance and the adjunctive closure forces in terms of power generation during coughing and squeezing. Urethral deformability was assessed from related values of urethral pressure and elastance.

Twenty‐eight (93%) patients had reduced permanent and/or adjunctive closure forces both at the bladder neck and midurethrally. Various combinations of reduced closure forces were found at the two sites of measurement. Different pathophysiological subgroups could be defined. In the largest group of patients both the permanent and the adjunctive closure forces were reduced. A small group of patients was characterized by decreased urethral deformability. It is concluded that both the bladder neck and mid‐urethral sphincter mechanisms are weakened in GSI. The underlying cause is not a single defect in urethral physiology; it is most often the result of weakening of one or more closure mechanisms (intramural and/or extrinsic) and the inability of the other to compensate. The identification of pathophysiologic subgroups may improve the scientific basis for selection of treatment modalities.
Relationship of fluid intake to voluntary micturitions and urinary incontinence in women
Authors: Wyman Jean F. , Elswick R. K. , Wilson Mary S. , Fantl J. Andrew
Published: March 2007

This retrospective study investigated the relationship between the volume of oral fluid intake and the frequency of voluntary micturitions and urinary incontinent episodes. The sample consisted of 126 community‐dwelling women who were age 55 years or older, ambulatory, mentally intact, and participants in a clinical trial on behavioral management for urinary incontinence. All subjects kept fluid and urinary diaries for 1 week. Analyses of Pearson's correlation coefficients between mean daily oral fluid volume intake and mean daily diurnal and nocturnal micturitions and urinary incontinent episodes were performed in women with sphincteric incompetence alone (N = 89), and those with detrusor instability with or without concomitant sphincteric incompetence (N = 37). The results indicated only weak positive correlations between fluid intake and voluntary micturitions. Similar weak positive correlations were observed with incontinent episodes even after controlling for the effect of diuretic use or urodynamic characterization. Modest positive relationships between fluid intake and the urinary variables were found in subjects with pure sphincteric incompetence. No correlations were found in subjects with detrusor instability. Additional analyses of these relationships suggests that fluid intake may have different effects based on the severity of the incontinence syndrome, and that these effects may vary by pathophysiologic condition. We conclude that the volume of fluid intake does not strongly influence voluntary micturition patterns or frequency of urinary incontinent episodes in community‐dwelling women.
In‐vitro contractile response of the rabbit corpus cavernosa to field stimulation and autonomic agonists and antagonists: A qualitative study
Authors: Broderick Gregory , Hypolite Joseph , Levin Robert M.
Published: March 2007

Field stimulation of rabbit corporus cavernosum tissue strips can result in relaxation, contraction, or a biphasic response depending on the frequency and the power utilized. In this study we characterized the autonomic components of this response by exposing corporal tissue strips to a variety of autonomic agonists and antagonists including phentolamine, isoproterenol, methoxamine, propranolol, bethanechol, atropine, and ATP. Low frequency electrical field stimulation produced a bi‐phasic response characterized by an initial relaxation followed by a contraction. High frequencies (≥ 32 Hz) produced contraction only. All responses were abolished by tetrodotoxin, indicating that both the contractile and relaxant responses to field stimulation are mediated by complex neural mechanisms. The initial relaxation response involves a combination of mediators which include musca‐rinic cholinergic stimulation, purinergic, beta‐adrenergic, and non‐adrenergic, non‐cholinergic (NANC) stimulation. The non‐cholinergic contribution to corporal smooth muscle relaxation appeared to be approximately equal in significance to the cholinergically mediated relaxation. Beta adrenergic stimulation mediated a direct relaxation of the corporal smooth muscle. The contractile portion of the bi‐phasic response was mediated by alpha‐adrenergic stimulation. Additionally we have noted a rebound contraction following termination of field stimulation at all frequencies that is not affected by adrenergic or cholinergic blockade and may reflect the field‐stimulated release of an endogenous smooth muscle contractile factor.
Effect of narcotic anesthesia and skeletal muscle paralysis on passive and dynamic urethral function of stress continent and incontinent women
Authors: Bump Richard C. , Huang Kou Chu , McClish Donna K. , Fantl J. Andrew , Wein Alan J.
Published: March 2007

The aim of this study was to assess the importance of conscious skeletal muscle activity on the resting and stressed urethral sphincteric mechanism in stress continent and stress incontinent women. We evaluated the effects of loss of consciousness induced by a narcotic‐based general anesthetic technique, with and without concurrent skeletal muscle paralysis, urethral sphincteric function. Nine premenopausal women who underwent vaginal hysterectomy without continence surgery had passive and dynamic urethral pressure profilometry performed within 24 hours before surgery, while asleep and totally paralyzed following endotracheal intubation before the start of surgery, while asleep and totally nonparalyzed at the end of surgery, and at the time of discharge from the hospital on the second or third postoperative day. Five subjects were stress incontinent and four had mild genuine stress incontinence but did not desire continence surgery with their hysterectomy. Measurements analyzed included urethral maximum closure pressure (MUCP) and functional length (FUL) from the passive profiles and bladder to urethra pressure transmission ratios (PTR) for each quarter of the urethra from the dynamic profiles. We found significant attenuation of urethral sphincteric function with stress due to muscle paralysis and loss of consciousness independent of muscle paralysis. Passive urethral function was more significantly depressed by paralysis than by loss of consciousness. These changes were statistically sifnificant only in stress continent subjects and not in the stress incontinent subjects, an observation that supports other evidence suggesting that there are important neuromuscular components in the pathogenesis of stress incontinence.
A comparative study of pelvic floor training and electrical stimulation for the treatment of genuine female stress urinary incontinence
Authors: Hahn Inger , Sommar Solveig , Fall Magnus
Published: March 2007

Twenty women with pure genuine stress urinary incontinence were randomly allocated to 6 months of pelvic floor training or intravaginal electrical stimulation. The result was evaluated with a pad test and patients' rating of efficacy. Patients not cured by the first treatment given were offered the other one. A long‐term follow‐up was done 4 years after concluding treatment.

The group of patients initially treated with pelvic floor exercises (n = 10) were significantly improved according to the pad test (P < 0.01). This corresponded very well to the subjective result, one patient being cured, five reporting insignificant symptoms, and the remaining four an improvement. The results were similar in patients allocated to intravaginal electrical stimulation (n = 10) (P < 0.05): one patient cured, four having insignificant symptoms, three improved, and two unchanged. We did not find any significant difference of results between the two groups of treatment (P < 0.10). Follow‐up after 4 years in 19 patients revealed that 1 patient was further improved, 8 patients were unchanged and 5 had deteriorated. Five women were operated during the follow‐up period.

Pelvic floor training is an adequate method for treatment of stress urinary incontinence. Even patients with severe incontinence may show a very good result. However, a sustained effect presupposes continuing exercise and during the follow‐up period of 4 years a quarter of the patients had to be operated upon to obtain permanent cure. The study also indicated that patients undergoing both treatments were further improved during the second course of treatment.
The relationship between external anal and external urethral sphincter activity in continent women
Authors: Burgio Kathryn L. , Engel Bernard T. , Quilter Reginald E. , Arena Vincent C.
Published: March 2007

The relationship between the external anal sphincter and the periurethral sphincter muscles is an unresolved issue. Recordings of the external anal sphincter (EAS) are commonly used to indicate the responses of the urethral sphincter during urodynamic evaluations and in biofeedback procedures for the treatment of urinary incontinence. This study examined the validity of using anal sphincter training to teach control of the external urethral sphincter. Subjects were 5 continent women, aged 37–51 years, who reported being free of all urologic symptoms. Using visual biofeedback of anal sphincter pressure, subjects were trained to voluntarily contract the sphincter to four amplitudes: 5, 10, 15, and 20 mmHg (6.8, 13.6, 20.4, and 27.2 cmH2O). Then they were guided through a series of controlled anal sphincter contractions, while the response of the urethral sphincter was measured using surface electrodes embedded in a Foley catheter. At each of four bladder volumes, subjects performed 16 contractions (four contractions at each of the four amplitudes). The order of contractions was counterbalanced, using a Latin square design. The results show a strong, statistically significant, monotonic relationship between the magnitude of anal sphincter contraction (pressure) and the level of urethral sphincter electromyographic (EMG) activity. The results support the use of the external anal sphincter as an indicator of urethral sphincter activity for the purpose of conducting biofeedback in the treatment of urinary incontinence.
Handwashing in the cystometric evaluation of detrusor instability
Authors: Mayer Robert , Wells Thelma , Brink Carol , Diokno Ananias , Cockett Abraham
Published: March 2007

Ambulatory community living women were evaluated for complaints of urinary incontinence. Diagnostic testing included a detailed history and physical examination, urinalysis, full bladder stress testing, and urodynamic studies consisting of uroflometry, urethropro‐filometry, and provocative water cystometry. Provocative maneuvers included coughing, heel bouncing, and handwashing. Uninhibited contractions were detected during cystometry in 34 of the 112 patients who completed diagnostic testing. The majority (74%) of the 34 patients with detrusor instability demonstrated evidence of uninhibited contractions during the filling phase of cystometry; coughing elicited contractions in 20%, heel bounces in 9%, and handwashing in 68% of patients, respectively. Of the nine patients with detrusor instability who did not have contractions during filling, all nine demonstrated bladder contractions after handwashing, whereas coughing and heel bouncing each elicited contractions in one patient apiece. In 66 patients who had evidence of stress‐related urine loss during the cystometric study, all but one lost urine with coughing but only 14% after handwashing. These findings suggest handwashing may be a sensitive and specific stimulus for detection of detrusor instability during cystometric testing.