bluuebunny/crossref_metadata_2025_split huggingface dataset:
Urodynamic findings in the lower urinary tract: I. Stress‐incontinent vs. ‐continent women
Authors: Van Venrooij Ger E. P. M. , Boon Tom A. , Vervest Harry A. M. 
Published: March 2007

AbstractUrodynamic findings in 250 patients with objective stress incontinence were compared with those of 108 controls without abnormalities. Patients with any component of motor‐urge incontinence were discarded from the study. The results were as follows: abdominal straining to void was significantly higher in the stress‐incontinent group; urethral resistance. maximal urethral closure pressure, and the relative urethral leakage pressure was significantly lower in the stress‐incontinent group. In light of the higher incidence of inefficient voiding pallerns seen in the stress‐incontinent population, preoperative urodynamic evaluation including cystometry with pressure flow studies, is important to exclude or at least be aware of the possibility of postoperative bladder‐emptying problems—apart from the need to exclude underlying motor instability.Relative urethral leakage pressure measurements were significantly lower than maximal urethral closure pressure measurements in stress‐incontinent patients. Urethral closure pressure profilometry is recommended in patients who are considered for retropubic urethropexy.
Urodynamic differentiation of parkinson disease and the shy drager syndrome
Authors: Berger Yitzhak , Salinas Jesus N. , Blaivas Jerry G. 
Published: March 2007

AbstractThe urodynamic findings of 29 patients with Parkinson disease (PD) and lower urinary tract symptoms were compared with those of nine patients with the Shy‐Drager syndrome (SD). All patients with PD had bladder contraction and normal filling pressures, and 90% had detrusor hyperreflexia. Among the patients with SD, 67% had detrusor areflexia, 33% had involuntary bladder contractions, and 45% had poor vesical compliance. In all patients with SD who had a voiding cystourethrogram, an open bladder neck at rest was demonstrated, but it was found only in those with PD who had prior prostatectomy. The electromyography of the external sphincter showed some form of lower motor neuron lesion in all patients with SD, but it was normal in 39% of PD patients and consistent with just involuntary sphincteric activity in 61%. A neurological evaluation of patients with typical and atypical Parkinsonism can assist in differentiating between these two entities.
Innovation in urodynamic testing: Report of the first fully computerized work station
Authors: Shank Reed A. , Barnes Margaret M. , Benz Steven A. , Bracken R. Bruce 
Published: March 2007

AbstractWe have conducted the first clinical trials on a new fully computerized urodynamic instrument on a referral population of 1,690 patients. The instrument performed the full range of urodynamic tests equivalent to that of a six‐channel strip chart recorder. The computer was found capable of recording urodynamic tracings, storing the data on computer files, and generating graphic summaries of test results. The computerized work station was found to be easy to operate, safe for patient use. accurate in reporting results, and durable in active clinical use. Computer technology is proven well adapted to urodynamic testing with both clinical and research applications.
In vivo urinary bladder function in rats following prolonged diabetic and non‐diabetic diuresis
Authors: Longhurst Penelope A. , Wein Alan J. , Levin Robert M. 
Published: March 2007

AbstractChanges in urinary bladder function are present in animal models of diabetes mellitus. In vivo cystometry in diabetic rats shows a bladder with increased capacity and a raised threshold for initiation of the micturition reflex. At sacrifice, diabetic rats have bladder hypertrophy, resulting in approximately a doubling of the bladder weight.This study was designed to characterize the effects of diabetes on micturition in the streptozotocin‐diabetic rat. For comparative purposes, two different control groups were examined: 1) age‐matched control rats and 2) age‐matched rats which were given 5% sucrose to drink. Sucrose‐fed rats consumed large volumes of fluid resulting in diuresis and bladder hypertrophy.Fluid consumption and excretion were significantly increased in diabetic and sucrose‐drinking rats. In addition, the diabetic rats both drank and excreted more than the sucrose‐drinking rats. Control rats had twice as many micturitions during the dark cycle than during the light cycle, but the volume micturition during the dark cycle was less than one‐half the volume per micturition during the light cycle. Sucrose drinking rats had the same number of micturitions as control rats during the light cycle. but the volumes per micturition were significantly increased. During the dark cycle, the number of micturitions increased four‐fold and the volume per micturition was significantly increased compared to controls. The diabetic rats, in contrast to the two control groups, had a significant increase in the number of micturitions during the light and dark cycles. Similar to the sucrose drinking rats, the volumes excreted per micturition were significantly greater than the normal controls. The data are discussed with regard to the effects of prolonged diuresis on bladder function and hypertrophy.
Continence recovery following radical prostatectomy
Authors: O'Donnell Pat D. , Finan Barre F. , Barnett Troy , Brookover Todd 
Published: March 2007

AbstractEarly postoperative continence problems following radical prostatectomy may occur in some patients, but continence usually improves during the first year following the operative procedure. The objective of this study was to assess the incidence of early postoperative continence problems and to determine the subsequent continence recovery over time. In 65 patients having a radical prostatectomy, mild and moderate incontinence occurred commonly at one month and three months following surgery. but significant improvement occurred at 6 months and 1 year. While most patients who have early postoperative incontinence will have recovery of continence function during the first year, the more severe early continence problems are more likely to persist as a prolonged continence dysfunction.
Pelvic floor muscle exercise for the treatment of female stress urinary incontinence: II. Validity of vaginal pressure measurements of pelvic floor muscle strength and the necessity of supplementary methods for control of correct contraction
Authors: Bø Kari , Kvarstein Bernt , Hagen Rolf R. , Larsen Stig 
Published: March 2007

AbstractThe present investigation comprises three methodological studies concerning vaginal pressure measurements of pelvic floor muscle (PFM) strength. Vaginal pressure was measured by a balloon (6.7 ± 1.7 cm) connected by a catheter to a pressure transducer. The balloon was placed with the middle of the balloon 3.5 cm inside the introitus vagina.In fourty‐seven women, mean age 44.9 years (24–64), observation of movement of the vaginal catheter during PFM contraction verified 7 inconclusive results from perineovaginal palpation and was the most valid way to distinguish between correct and incorrect PFM contraction.Vaginal pressure rise was obtained regardless of correct or incorrect PFM contraction, showing that vaginal pressure is not specific for PFM contraction. However, as the action of the PFM is elevation, a simultaneous inward movement of the vaginal catheter is present only during correct PFM contraction.Degree of influence of various muscle groups on vaginal pressure was investigated in 14 women using two different balloons, one having a silicone reinforcement of the tip. It was found that the median contraction value of muscles other than the PFM did not exceed contraction of PFM alone. No significant difference was observed using the two types of balloons.In three physical therapists EMG activity of the lower m. rectus abdominis was recorded during maximal PFM contractions. A rise in EMG activity always occurred during maximal contractions even if the women actively tried to relax the abdominal muscles.It is concluded that vaginal pressure measurement of PFM strength is valid with simultaneous observation of inward movement of the balloon catheter. Vaginal pressure rise due to simultaneous contraction of other muscles is probably not larger than pressure rise due to intended PFM contraction. Reinforced balloon tip will not change pressure recording, and rise in EMG activity of lower abdominal muscles seems unavoidable during maximal PFM contraction.
Urinary tract reconstruction: Applied urodynamics
Authors: Key D. , Wan J. , Grainger R. , McDermott T. , McGuire E. J. , Bloom D. A. 
Published: March 2007

AbstractSixty‐four patients underwent urinary reconstruction guided by urodynamic investigation. Twenty‐eight patients had myelodysplasia (MM) and 26 had spinal cord injuries (SCI). Operative outcomes were assessed by repetitive urodynamic testing.Bladder reservoir function and detrusor contractile activity were correctly assessed in all 64 patients. Operative creation of a more adequate reservoir was required in 58 patients.Assessment of urethral continence function was inaccurate in six instances wherein we judged urethral sphincter function adequate when, in fact, it was not. Ureteral function was judged radiographically or by furosimide renography, or Whitaker perfusion testing. In the two instances where ureteral function was in doubt, it made no difference in outcome. There was a striking resolution of ureteral radiographic abnormalities after reconstruction which we attribute to the low‐pressure reservoir.
Intra‐ and inter‐ observer variations in classification of urinary flow curve patterns
Authors: Jørgensen J. Balslev , Jensen K. M.‐E. , Klarskov P. , Bernstein Inge , Abel Ivan , Mogensen P. 
Published: March 2007

AbstractTo assess the validity of classification of urinary flow curve patterns, six doctors at different levels of urodynamic education were asked to classify 176 urinary flow curves. The curves had been obtained from elderly, randomly selected men without voiding problems. Five flow curve patterns were defined both graphically and in writing, and the six observers were asked to classify the 176 curves into one of the five categories.The agreement between the six observers was calculated as a frequency, and this value was corrected for the chance agreement. Some of the observers were asked to reevaluate the curves after 3 months, and the interobserver variation was calculated.We conclude that if of any value, the classification of urinary flow curves must be undertaken by urodynamically trained persons. In that case there is a good chance that the classification can be reproduced by any other urodynamically trained person.
Effect of alcohol on bladder function: A uroflowmetric and cystometric study
Authors: Taari Kimmo , Ruutu Mirja , Lehtonen Timo 
Published: March 2007

AbstractAlcohol intake may provoke urinary retention in young persons without a previous history of obstructive urinary tract disease. The mechanism by which alcohol causes urinary retention is unknown. Ten healthy male volunteers had urodynamic studies performed before and under the influence of alcohol. Detrusor instability was found in four test persons under the influence of alcohol. The mechanisms by which alcohol may cause urinary retention are discussed.
Computer simulation of the neural control of bladder and urethra
Authors: Hosein Rasheed A. , Griffiths Derek J. 
Published: March 2007

AbstractA large number of neural reflex loops may be involved in voiding and leak‐free storage of urine. The simplifying hypothesis that only very few reflexes are needed to account for most of the observed behavior has been tested by quantitative simulation of the lower urinary tract and its control system. The mechanical part of the simulation, involving detrusor contraction strength and a carefully defined urethral resistance, is based on previous work. The postulated neural control system involves two mutually inhibitory control regions, leading to a bistable (storage‐voiding) system, and reflexes driven by a single afferent signal with contributions from bladder wall tension and urethral distension. Because the control system is bistable, each of the two afferent contributions has two possible effects, so that four distinct reflexes appear to operate. Simulations, with and without these reflexes, show that this system accounts for many features of normal voiding, stop tests, and catheter voiding. The behavior is not sensitive to arithmetic details of the calculations involved. After triggering by a simulated suprapontine control signal, the voiding detrusor contraction is initially amplified by the afferent signal from the detrusor but it is sustained until the bladder is empty by the urethral afferent. Mechanical urethral obstruction causes slight residual urine. Breakdown of the mutual inhibition of the two control regions leads to detrusor instability, suggesting that this condition may sometimes have a central origin.
Assessment of detrusor contraction strength or contractility
Authors: Griffiths Derek J. 
Published: March 2007

AbstractThis paper is a review of the various methods that have been proposed to extract an assessment of the detrusor contraction strength or contractility from pressure/flow studies of voiding. Most of the methods are fundamentally similar, differing mainly in their degree of sophistication and ease of interpretation. Guidelines for choosing among them are suggested. Fundamental equations are given in the appendix.
Estimation of contractility parameters for the urinary bladder
Authors: van Mastrigt R. 
Published: March 2007

AbstractThe contractility of (urinary bladder) smooth muscle can be described in terms of a relation between its contraction force and its shortening velocity. To a sufficient degree of accuracy this relation is approximated by the hyperbolic Hill equation, originally derived for striated muscle. Allowing for a constant “curvature” of the relation, this equation is completely determined by the parameters Po (isometric pressure) and vmax (maximum contraction velocity).Micturition results from the interaction of bladder contractility with the resistance of the urethra. If variations in urethral resistance occur, a plot of bladder wall shortening, calculated from flow rate, as a function of detrusor pressure during micturition traces part of the contractility relation. In the present study 241 micturitions out of a population of 2,073 measurements taken from a mixed group of patients, i.e., 12% of pressure‐flow studies, could thus be fitted with a Hill curve, yielding the parameters Po and vmax.A method was developed for estimating vmax from pressure and flow measured throughout any micturition. When applied to a test population it was found that the thus estimated contraction velocity called vest correlated significantly with the “true” contraction velocity vmax (Spearman's rank correlation coefficient 0.77, significant at the 0.1% level). Vest was not significantly different in groups of obstructed versus unobstructed patients, but it was found to be significantly lower in unobstructed patients that voided with significant residual volume, indicating that this parameter is not biased by urethral resistance and represents (one aspect of) the detrusor contractility.
Contraction strength variance during pressure/flow studies
Authors: Constantinou C. E. 
Published: March 2007

AbstractThe parameters of bladder pressure, urine flow rate and strength of contraction (W) during voiding were evaluated in female patients with stress urinary incontinence (SUI) and compared to non‐SUI patients. The long‐term modification in these parameters produced by endoscopic bladder neck suspension (BNS) was also evaluated in the SUI patients. Comparisons were made between the direct measurements of bladder pressure and flow rate during voiding with the indirect computations of W. The parameter, W, was evaluated at the prevoiding stage, and during micturition at 20% and 80% of voided bladder volume. The maximum W attained was also computed. Analysis was based on an algorithm of calculating the single valued variable W from detrusor pressure and flow rate information that was digitized by a real time computer. Data were obtained from a total of 80 patients; 49 patients with non‐SUI having a mean age of 50 ± 16 years (mean ± SD) and 31 patients 56 ± 12 years with SUI. The pre‐operative values of W and pressure/flow parameters in the 31 patients with SUI were compared with postoperative values obtained 26 months following (BNS). The results show that SUI patients void at a significantly lower pressure than non‐SUI patients and at approximately the same flow rate. There is no statistically significant difference between SUI and non‐SUI patients in the value of W at any stage of the voiding cycle. Comparison of pre‐operative to postoperative values of these parameters also shows that BNS did not produce significant changes in contraction strength W although the direct measurements of voiding pressure significantly increased and flow significantly decreased. It is concluded that the contractility of the bladder is maintained at a preset physiological level in the presence of physiologically or surgically changing urethral impedance.
Effects of bladder volume on detrusor contractility during sacral nerve stimulation
Authors: Walter James S. , Tang Pei C. , Wheeler John S. 
Published: March 2007

AbstractIn spinalized dogs under Nembutal anesthesia, electrical stimulation of sacral nerves with electrodes inserted into the sacral canal induced maximal urinary bladder contractions. The amplitude of the peak vesical pressure varied with the bladder volume. Active peak pressures were highest when the bladder volume was 25 to 50 ml. Pressure declined to less than 50% of its maximum value at a bladder volume of 400 ml. In order to further describe the contractile properties of the detrusor muscle, wall tension was calculated using Laplace's law, wall stress was determined as tension per unit wall thickness, and the circumference of the vesical volume was calculated as a measure of muscle length. Active detrusor wall tension during stimulation tended to be highest at the midrange of volumes, whereas the wall stress increased linearly with increasing bladder volume. This increase in wall stress was secondary to the wall becoming thin at large volumes.
Non‐neurogenic neurogenic bladder: The relationship between intravesical pressure and the external sphincter electromyogram
Authors: Rudy Delbert C. , Woodside Jeffrey R. 
Published: March 2007

AbstractWe retrospectively reviewed the urodynamic studies of 14 patients: 3 males and 11 females, previously diagnosed clinically and urodynamically as having non‐neurogenic neurogenic bladder. The mean age of the patients was 10 years (range 4–24 years). We identified 3 urodynamic features in this patient population that are distinct from those seen in patients with true detrusor‐external sphincter dyssynergia: (1) quieting of the external sphincter electromyogram (EMG) immediately prior to the onset of a detrusor contraction, (2) quieting of the EMG during the upslope of a detrusor contraction, and (3) augmented EMG activity during the downslope of the detrusor contraction. Although both involve incoordinate bladder and pelvic floor/external sphincter activity, a simple cystometrogram with EMG may allow reliable differentiation between true detrusor‐external sphincter dyssynergia and non‐neurogenic neurogenic bladder.
Urethral pressure increment preceding and following bladder pressure elevation during stress episode in healthy and stress incontinent women
Authors: Thind Peter , Lose Gunnar , Jösrgensen Lisbeth , Colstrup Hans 
Published: March 2007

AbstractThe urethral pressure elevation preceding and following pressure elevation in the bladder during cough was studied in 30 healthy volunteers and 30 genuine stress‐incontinent women. The pressures were measured by means of a double microtip transducer catheter with the distal sensor in the bladder and the proximal sensor covered with a water‐filled balloon and placed at the bladder neck, in the high‐pressure zone, or distally in the urethra. In both groups of women a urethral pressure elevation was demonstrated before and after pressure elevation in the bladder during a cough. A urethral pressure elevation ≥ 5 cm H2O both before and after bladder pressure elevation was demonstrated in one third and one fourth of healthy and stress‐incontinent women, respectively. The initial urethral pressure rise in the mid‐ and distal urethra was statistically significantly higher in the healthy women. During abrupt coughing the initial urethral pressure rise disappeared. The pelvic floor as part of the demarcation of the abdominal cavity is positively taking part in the intraabdominal pressure generation during stress episodes, and the urethral pressure increment in advance of bladder pressure elevation reflects an active contraction. A lowering of this initial urethral pressure rise may be a contributing factor of the pathogenesis of genuine stress incontinence, although it does not necessarily result in stress incontinence.
Correlation of in vitro pressure generation with urinary bladder function
Authors: Levin Robert M. , Kato Kumiko , Lin Alex T. , Whitmore Kristene , Wein Alan J. 
Published: March 2007

AbstractUrinary bladder function consists of a filling and storage phase followed by an active coordinated expulsion phase. A large part of our knowledge of bladder function, as well as bladder physiology and pharmacology, comes from a variety of in‐vivo and in‐vitro experimental animal models.Of the in‐vitro methodologies available for the study of bladder smooth muscle, the isolated bladder smooth muscle strip techniques and isolated whole bladder techniques are two of the most popular. In general, the ability to generate pressure in the non‐emptying whole bladder model is directly related to phasic contraction of the bladder smooth muscle, and can be equated with the response of isolated strips. Although both techniques generate useful and important information, one must be very careful in making conclusions concerning bladder function based solely on contractile data.We have studied the volume‐pressure relationship of the bladders of control rabbits and of those subjected to bladder outlet obstruction (2 week) and unilateral ischemia (2 week). For each bladder, in‐vitro cystometry, pressure generation, and the ability of the bladder to empty (in response to both bethanechol and field stimulation) was determined. Although it was clear that outlet obstruction and unilateral ischemia induced marked alterations in bladder compliance, capacity, and the ability to empty, bladder pressure generation was not significantly affected. These studies support the view that contractile studies in and of themselves cannot be used to describe the functional state of the bladder. Only through the application of several techniques including studies on bladder compliance, capacity, and the ability of the bladder to empty can the functional state of the bladder be evaluated.