P. D. Ramsden

Outcome of elective prostatectomy.

OBJECTIVES--To determine the symptomatic and urodynamic outcome of elective prostatectomy and to establish whether the outcome is influenced or can be predicted by preoperative urodynamic measurements. DESIGN--Prospective non-randomised study with follow up at a mean of 11 months after operation. Most men were assessed jointly by a urologist and a general practitioner. SETTING--Department of urology in a teaching hospital serving a large district population. PATIENTS--253 Men listed for elective prostatectomy because of symptoms and low urinary flow rates (less than 15 ml/s) and excluding those already on a waiting list or with acute urinary retention, clinically apparent prostatic cancer, and neurological or cerebrovascular disease; 217 (86%) were followed up. INTERVENTION--Elective prostatectomy. MAIN OUTCOME MEASURE--Classification on the basis of relief of symptoms assessed by patients and urologist and general practitioner and of symptom scores obtained by questionnaire. RESULTS--Of the 217 men followed up, 171 (79%) had a satisfactory subjective review and 155 (72%) had a satisfactory review and also low symptom scores. An unsatisfactory outcome was associated with preoperative symptoms of urge incontinence, small prostatic size and resected weight, low voiding pressures, and low urethral resistance. Preoperative maximum urinary flow rates did not predict outcome. Men with poor outcome could be classified into two groups: those with irritative symptoms who were more likely before operation to have had urge incontinence and detrusor instability and men with symptoms of poor urinary flow who were more likely before operation to have had a small prostate, low voiding pressures, and low urethral resistance. In patients in the second group flow rates or voiding pressures improved little after operation. Men with stable detrusors and either low urethral resistance or low voiding pressures were less likely to do well after prostatectomy, but despite these associations preoperative urodynamic measurements were unable to predict outcome accurately. CONCLUSIONS--Prostatectomy was satisfactory in relieving symptoms and improving urodynamic measurements in most men, but even in those with classic symptoms and low urinary flow rates a substantial minority experienced little improvement afterwards and urodynamic measurements did not accurately predict outcome in individual patients.

NONINVASIVE MEASUREMENT OF BLADDER PRESSURE BY CONTROLLED INFLATION OF A PENILE CUFF

PURPOSE A noninvasive test providing reliable objective quantification of bladder pressure during the voiding cycle would make an important contribution to the management of lower urinary tract symptoms. We developed a new noninvasive test to measure bladder pressure in males based on controlled inflation of a penile cuff during voiding. We compared the new technique with simultaneous invasive bladder pressure measurement. MATERIALS AND METHODS We evaluated 7 volunteers and 32 patients. A conventional pressure flow study was performed first. The bladder was refilled, a penile cuff was fitted and after voiding commenced the cuff was inflated in steps of 10 cm. water every 0.75 seconds until urine flow was interrupted. The cuff was rapidly deflated, allowing flow to resume, and the cycle was repeated until the end of voiding. The flow rate was graphed against cuff pressure for each interruption cycle to determine the pressure at which flow was interrupted. This pressure was compared with simultaneous invasive isovolumetric bladder pressure. RESULTS Invasive and noninvasive pressure measurements agreed well. Average cuff pressure at interruption of flow exceeded mean simultaneous isovolumetric bladder pressure plus or minus standard deviation by 14.5 +/- 14.0 cm. water. CONCLUSIONS The new method provides noninvasive quantitative information on voiding bladder pressure in males. Further study is required to assess whether the technique can contribute to the management of lower urinary tract symptoms.

Ambulatory monitoring of bladder and detrusor pressure during natural filling

We have developed a system to perform fully ambulatory monitoring studies of the bladder. Bladder and rectal pressures are recorded during natural filling of the bladder for up to 6 hours. This system has been evaluated in 19 studies performed on 15 patients. The mean duration of the studies was 3 hours 51 minutes (standard deviation +/- 1 hour 3 minutes) and the mean number of voids per patient was 3.8 +/- 2.2. Visual inspection of the recorded data showed that subtraction of the rectal trace from the bladder trace provided a useful detrusor trace when subjects were ambulant as well as resting. When ambulant, movement caused typical peak-to-peak pressure variability in the bladder and rectal traces of approximately 30 +/- 20 cm. water (mean and standard deviation of peak-to-peak pressure for typical ambulant 5-minute sections for each patient), which after subtraction was reduced on the detrusor trace to 10 +/- 5 cm. water. The equivalent figures when resting were 9 +/- 5 cm. water, subtracting to less than 5 cm. water for the detrusor. Further measurements also were calculated for the whole of each trace. The system provided good quality recordings and should prove useful in future evaluations of natural fill urodynamic studies.

Long-term monitoring of bladder pressure in chronic retention of urine: the relationship between detrusor activity and upper tract dilatation.

We investigated 41 men with chronic retention of urine owing to bladder outflow obstruction by long-term monitoring of bladder pressure and conventional cystometry to determine the relationship between detrusor pressure and upper tract dilatation. We confirmed that high pressures during conventional filling cystometry were common in men with upper tract dilatation. However, important differences were demonstrated between long-term monitoring and conventional cystometry. The pressure increase during the natural filling phase of long-term monitoring was significantly smaller than that during conventional cystometry. Detrusor instability was found in 88 per cent of the men during long-term monitoring but in only 51 per cent during conventional cystometry (p less than 0.001). High frequency unstable detrusor contractions during long-term bladder pressure monitoring were associated significantly with upper tract dilatation (p less than 0.0001) and correlated significantly with impairment of glomerular filtration rate (rs equals -0.7339, p less than 0.001).

Ambulatory Monitoring of Bladder Pressure in Low Compliance Neurogenic Bladder Dysfunction

Upper tract dilatation is an important complication of neurogenic bladder dysfunction. Risk factors include incomplete bladder emptying with large residual volumes of urine and high tonic increases in bladder pressures during artificial filling. However, on natural bladder filling many of these patients do not have high tonic increases in detrusor pressures. We compared conventional urodynamic studies with ambulatory monitoring during natural bladder filling in 66 patients with low compliance neurogenic bladder dysfunction. There were marked differences in the tonic increase in bladder pressure during filling and in compliance during artificial bladder filling compared with ambulatory monitoring. Faster filling rates during artificial filling resulted in greater end filling pressures and lower compliance but the lowest increases in bladder pressure were found during ambulatory monitoring with natural bladder filling. During natural bladder filling significantly more patients had phasic changes in detrusor pressure; a high intensity of phasic activity during ambulatory monitoring correlated with high end filling pressures during artificial bladder filling. Upper tract dilatation was associated with large volumes of residual urine, high resting bladder pressures and low bladder compliance on filling at 100 ml. per minute. However, upper tract dilatation was most strongly associated with high intensity phasic pressure activity during natural bladder filling in combination with high residual urine volumes and high resting bladder pressures. On multivariate statistical analysis the intensity of phasic pressure activity during ambulatory monitoring was the best discriminator between patients with dilated and normal upper tracts. Our study has highlighted important differences in the results obtained by artificial filling cystometry and ambulatory monitoring during natural bladder filling. In particular, high increases in pressure did not occur during natural bladder filling, apparently being replaced by phasic activity. Within this group of patients who had the high risk factor of low bladder compliance measured during artificial bladder filling, a combination of greater residual urine volumes, greater resting pressures and greater phasic activity during natural bladder filling was found in patients with upper tract dilatation.

TRANSMISSION OF PENILE CUFF PRESSURE TO THE PENILE URETHRA

PURPOSE We developed a noninvasive method to measure voiding bladder pressure by inflating a penile cuff to interrupt flow. We tested the underlying assumption that cuff pressure is transmitted to the penile urethra. MATERIALS AND METHODS In 35 men we simultaneously recorded penile cuff and urethral pressure during 2 experimental protocols for 6 cuffs of various widths and manufactures. Initially a urethral pressure transducer was placed at the mid point of the cuff and urethral pressure was continuously recorded during cuff inflation. In experiment 2 cuff pressure was set at 120 cm. water and the urethral pressure profile was measured by withdrawing the urethral transducer through the cuff width. RESULTS There was excellent agreement of cuff with urethral pressure over the range of 0 to 200 cm. water for cuffs 37 to 54 mm. wide. Narrower cuffs showed wider variation with less efficient transmission of cuff pressure to the urethral lumen. Similarly maximum pressure in the urethral pressure profile showed best agreement for cuffs 38 and 46 mm. wide. Wider cuffs produced higher and narrower cuffs produced lower transmitted pressure within the urethra. Cuff performance was also related to penile size. Results had good within-subject repeatability. CONCLUSIONS We demonstrated that pressure transmission from cuff to urethra is optimal at a cuff width of 40 to 50 mm. and recommended this width for other investigations of noninvasive bladder pressure measurement.

Variation in Invasive and Noninvasive Measurements of Isovolumetric Bladder Pressure and Categorization of Obstruction According to Bladder Volume

PURPOSE We developed a noninvasive test that provides an estimate of isovolumetric bladder pressure by measuring the pressure required to interrupt voiding using controlled inflation of a penile cuff. We noted variation in serial measurements obtained during a single void and, therefore, we determined whether this represents variation in detrusor contraction strength, as predicted in previous studies, or measurement error. MATERIALS AND METHODS A total of 36 symptomatic men underwent simultaneous invasive and noninvasive pressure flow studies. Corresponding values of isovolumetric bladder pressure and cuff interruption pressure were recorded at each flow interruption and grouped according to bladder volume to calculate measurement error and bias at various points during a void. Individual variation in the 2 measurements across a range of normalized bladder volumes was then examined using ANOVA. RESULTS Cuff interruption pressure showed a consistent level of accuracy as an estimate of isovolumetric bladder pressure across a range of volumes. There were similar, statistically significant differences in isovolumetric bladder pressure and cuff interruption pressure recorded at specific volume increments with the highest values seen in the mid range and the lowest seen at lower bladder volumes (each p <0.01). When plotting, the maximum recorded value of cuff interruption pressure in each individual on our proposed noninvasive pressure flow nomogram provided the best diagnostic accuracy for obstruction. CONCLUSIONS This study shows that cuff interruption pressure varies in the expected manner with bladder volume and provides a consistent estimate of isovolumetric bladder pressure throughout a void. These data provide important guidance for interpreting noninvasive pressure flow studies and classifying obstruction on the proposed nomogram.

The outcome of prostatectomy on chronic retention of urine.

A total of 68 men with bladder outflow obstruction and chronic retention (residual urine greater than 300 ml.) underwent investigation before and after prostatectomy with medium fill cystometry and natural fill long-term bladder pressure monitoring. Postoperatively, upper tract dilatation (present in 28 men preoperatively) resolved in all but 2 men and serum creatinine levels improved significantly. Irritative and obstructive symptom scores improved postoperatively (p less than 0.00006), although 17% of the men still had significant symptoms. Residual urine volumes decreased and flow rates improved (p less than 0.00006) but 32% of the men still had a residual urine of greater than 200 ml. Urodynamic parameters improved during medium fill cystometry and long-term monitoring. The main risk factors for upper tract dilatation are a pressure increase during bladder filling on conventional cystometry and the frequency of phasic detrusor activity during long-term monitoring, and they decreased postoperatively.

Tanagho bladder neck reconstruction in the treatment of adult incontinence.

We studied the effectiveness of tubularized bladder neck reconstruction in the treatment of 8 patients with complex incontinence using urodynamic and clinical methods. The patients had undergone Tanagho bladder neck reconstruction within the last 10 years. Three of the 8 patients were judged unsuitable for artificial sphincter implantation because of severe scarring, and loss of urethral and vaginal tissue. There were 7 women with epispadias or severe urethral damage as a consequence of obstetrical or gynecological procedures. Five patients underwent 7 concurrent procedures at the time of bladder neck reconstruction, including colposuspension (4), and closure of a fistula involving the bladder neck (1) and urethra (1) plus vaginal reconstruction (1). Of 8 patients 5 (63%) were completely continent and satisfied, 2 underwent ileal conduit diversion (1 because of incontinence and 1 refused clean intermittent self-catheterization), and 1 is incontinent and awaiting further treatment. The best results were noted in patients with a healthy bladder and periurethral tissues. Four of 5 patients (80%) deemed potentially suitable for artificial urinary sphincter insertion were satisfied compared to only 1 of 3 (33%) unsuitable for artificial urinary sphincter insertion. The Tanagho bladder neck reconstruction is a useful addition to the procedures that may be used by the reconstructive urological surgeon in the treatment of carefully selected patients with complex incontinence, particularly in women with epispadias who for various reasons may wish to avoid the long-term potential complications of an artificial urinary sphincter.