[Show abstract][Hide abstract] ABSTRACT: To determine whether categorisation of bladder outlet obstruction (BOO) using measurements of bladder pressure and urine flow obtained by a novel noninvasive medical device (the penile cuff test) improves prediction of outcome from endoscopic prostatectomy (TURP).
A consecutive cohort of 208 men undergoing TURP following standard assessment in our institution was recruited, and 179 (86%) completed the protocol. Each subject underwent a penile cuff test prior to surgery; outcome was assessed by change in IPSS at 4 mo. The proportion of men with good outcome (>50% reduction in IPSS) was compared according to categorisation by noninvasive bladder pressure and urine flow measurements.
The cuff test was completed by 93% of men with 2% experiencing an adverse event. Men categorised as having BOO by the test (37% of total) had an 87% chance of a good outcome from TURP (p<0.01), whilst of those deemed not obstructed (19% of total) 56% experienced good outcome (p<0.01). For the remaining men not categorised in these two groups, 77% had good outcome, which was identical to the result of the cohort as a whole (77%, p=NS).
Urodynamic categorisation using measurements obtained by the noninvasive penile cuff test improves prediction of outcome for men with LUTS undergoing TURP. This finding together with the ease and acceptability of the test suggest its suitability for office-based clinical use to assist men and their physicians in the selection for surgical treatment for relief of LUTS.
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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.
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.
No preview · Article · Jul 2006 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: A 23-year-old man presented with a painful penis following sexual intercourse. On examination he had a swollen, bruised penis that was tender on palpation, most markedly on the right lateral aspect.
Rupture of right corpus cavernosum.
Immediate surgical repair.
No preview · Article · Apr 2006 · Nature Clinical Practice Urology
[Show abstract][Hide abstract] ABSTRACT: The invasive nature of conventional voiding pressure measurement limits routine diagnostic use for men with LUTS and has encouraged research into non-invasive methods of categorising obstruction. We have developed a technique to measure isovolumetric bladder pressure non-invasively, the penile cuff test, which is well tolerated and quick to perform. When combined with flow rate, a sufficiently accurate diagnosis of BOO is made to enable improved prediction of outcome from TURP for most men tested. In addition, release of penile compression allows derivation of the penile compression/release index, which is also useful for categorisation of detrusor function during voiding.
[Show abstract][Hide abstract] ABSTRACT: Bladder pressure during voiding can be estimated by a noninvasive technique using controlled inflation of a penile cuff. This test provides a valid and reliable estimate of isovolumetric bladder pressure but to our knowledge the role of the test for the routine clinical treatment of patients with lower urinary tract symptoms (LUTS) has yet to be demonstrated. As a first step, we evaluated a proposed nomogram for the diagnosis of bladder outlet obstruction in men with LUTS using noninvasive measurements of pressure and flow.
Using a combination of theoretical calculation and experimental data the existing International Continence Society pressure flow nomogram was modified to allow noninvasive measurement of isovolumetric bladder pressure in place of detrusor pressure at maximum urine flow. Accuracy of the nomogram for classifying obstruction was then tested in a group of 144 men with LUTS who underwent an invasive and a noninvasive pressure flow study.
The modified nomogram identified men with obstruction with 68% positive predictive value and 78% negative predictive value. Predictive accuracy could be improved by adding an additional criterion of obstruction, that is maximum urine flow less than 10 ml second, whereby an identifiable 69% of all cases could be classified as obstructed (88% positive predictive value) or not obstructed (86% negative predictive value). In the remaining 31% of patients invasive pressure flow studies would provide additional information, although some results would remain equivocal.
The proposed nomogram combined with the additional flow rate criterion can classify more than two-thirds of cases without recourse to invasive pressure flow studies. We must now evaluate the usefulness of this classification for the treatment of men with LUTS.
No preview · Article · Nov 2005 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: We tested the hypothesis that the previously described penile urethral compression release (PCR) maneuver provides a valid diagnosis of bladder outlet obstruction (BOO) using automated rather than manual penile compression by controlled inflation of a penile cuff. We also investigated urodynamic events underlying generation of the PCR index.
A total of 150 subjects attending for pressure flow studies were studied using conventional and noninvasive cystometry. Patients were classified into urodynamic diagnostic groups using standard invasive studies. The PCR index was calculated for each individual from noninvasive penile cuff data and the results were summarized for each group. ROC analysis of the PCR index was performed to define an optimum threshold for BOO diagnosis. Simultaneous invasive and noninvasive data were used to define the relationship between the PCR index, bladder contractility and the maximum flow rate.
The mean PCR index +/- SD was significantly higher in the BOO group compared to the normal cystometry group (215% +/- 84% vs 93% +/- 39, p <0.01). ROC analysis showed that a PCR index of greater than 160% diagnosed BOO with 78% sensitivity, 84% specificity and a positive predictive value of 69%. There was a strong positive correlation between the PCR index and isovolumetric detrusor pressure, which is a measure of bladder contractility (r = 0.44, p <0.01).
The results of this study suggest that the PCR index combines valid estimates of bladder contractility and the maximum flow rate, and it represents a clinically useful, noninvasive urodynamic parameter for the diagnosis of BOO.
No preview · Article · Dec 2004 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: Preoperative assessment of detrusor function by pressure flow study (PFS) improves outcome from prostatectomy but is invasive and uncomfortable for the patient. We report on a large scale validation of a novel noninvasive assessment of detrusor contractility.
A flexible cuff placed around the penis was inflated automatically during voiding until flow interruption. Cuff pressure at interruption (pcuff.int) reflects isovolumetric bladder pressure (pves.isv), a measure of detrusor contractility. For comparison 151 symptomatic men performed the cuff test with simultaneous PFS monitoring. Test/retest agreement was assessed in 91 subjects who performed a cuff test without PFS on 2 occasions.
For the 117 (77%) subjects with an acceptable cuff pressure flow trace, Bland Altman analysis showed that pcuff.int overestimated pves.isv by a mean (s.d.) of 16.4 (27.5) cm H2O, predominantly due to the cuff being positioned below the bladder. For test/retest analysis 52 (57%) of the men who were able to attend twice provided acceptable cuff data on both occasions with a mean (s.d.) difference in pcuff.int of -3.3 (32.0) cm H2O, improving to 0.0 (20.3) cm H2O in a subgroup of 39 subjects who voided more than 150 ml. On questionnaire assessment 121 (80%) subjects preferred the cuff test to PFS.
The cuff test gives a valid and reproducible estimate of isovolumetric bladder pressure in a manner acceptable to patients, although test failure and variability of agreement require improvement. The test may be of value in the assessment of urinary symptoms and may aid in patient selection for prostatectomy.
No preview · Article · Nov 2004 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: As part of developing a noninvasive method to measure bladder pressure using an inflatable penile cuff, we tested the hypothesis that detrusor contraction is maintained without inhibition during the test.
Five healthy volunteers and 26 male patients with lower urinary tract symptoms underwent interruption of established urine flow by controlled inflation of a cuff placed around the penis with simultaneous invasive bladder pressure monitoring. After interruption of flow the cuff was rapidly deflated and voiding was allowed to resume. The bladder pressure was recorded before, during and after interruption of flow by cuff inflation.
During flow interruption an isovolumetric increase in detrusor pressure was observed. When the cuff was deflated the detrusor pressure quickly returned to preinflation values and urine flow immediately resumed. Intra-abdominal pressure did not change during the cuff inflation cycle.
Mechanical interruption of urine flow by controlled inflation of a penile cuff during voiding does not inhibit detrusor contraction. This finding further validates our noninvasive technique of bladder pressure measurement and supports ongoing studies into its clinical usefulness.
No preview · Article · Apr 2003 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: In the development of a non-invasive method for estimating isovolumetric intravesical pressure (pves,isv) we looked for a relationship between intra-abdominal pressure (pabd) and general build, expressed as body mass index (BMI) in men with lower urinary tract symptoms (LUTS).
In 100 consecutive male patients undergoing an invasive pressure flow study (PFS) the pabd was recorded continuously during filling and voiding. The magnitude at four set points was measured: before filling, after filling, during voiding and at the end of voiding. Patients' weight (kg) and height (m) were also recorded and their BMI (weight/height(2)) was calculated.
During the fill/void cycle pabd increased during bladder filling from 37 +/- 7 cm H2O (mean +/- SD) to 38 +/- 8 cm H2O, fell during voiding to 35 +/- 9 cm H2O before increasing to 36 +/- 8 cm H2O at the end of voiding. There was a clear relationship between the individual values of pabd and BMI (correlation co-efficient = 0.52) and to a lesser extent weight (correlation co-efficient = 0.42). The relationship with BMI was clarified by separating the subjects into groups of normal, overweight and obese.
A clear relationship between BMI and pabd was demonstrated, but because of the difficulties in quantifying it for an individual, it is impractical to apply an adjustment to non-invasive estimates of pves,isv.
No preview · Article · Jan 2003 · Neurourology and Urodynamics
[Show abstract][Hide abstract] ABSTRACT: To investigate the use of an inflatable perile cuff to obstruct flow progressively during voiding in order to provide a noninvasive measure of bladder pressure.
In this study, we explain the observed relationship of flow rate with applied cuff pressure by analogy with a simple physical model. The model comprised a fixed-pressure reservoir (simulating the bladder), a collapsible tube around which a fixed pressure could be applied (simulating the prostatic urethra), connected by rigid conduit to a further collapsible tube around which pressure could be applied (simulating the penile urethra and cuff). Flow was progressively obstructed by incremental increase of pressure applied to the "penile urethra," with the experiment being repeated for a range of fixed pressures applied to the "prostatic urethra."
The model reproduced the typical pressure/flow curves recorded during voiding by using penile cuff inflation in normal and obstructed men.
Our data led us to hypothesise that the relationship between cuff pressure and flow rate can be used to deduce bladder pressure during voiding, prostatic opening pressure, and urethral diameter at the flow-controlling zone, three indicators of lower urinary tract function. These measurements may add to the accuracy of diagnosis and quality of care for a large number of men with lower urinary tract symptoms.
No preview · Article · Jan 2003 · Neurourology and Urodynamics
[Show abstract][Hide abstract] ABSTRACT: Objective data are useful in quantifying a patient's lower urinary tract symptoms (LUTS). We are investigating the use of an inflatable penile cuff to obstruct flow progressively during voiding, and thereby determine the pressure p(cuff,int) at which flow is interrupted. The aim of this study was to determine the agreement between experienced observers in their estimates of p(cuff,int).
We recorded 486 cuff inflation cycles during 142 voids from 42 subjects recruited from urology out-patient's and prostate assessment clinics. Each inflation cycle was assessed independently by three experienced observers, a total of 1,458 ratings. According to our standard assessment procedure, the observers (i) indicated whether the inflation should be analyzed, (ii) estimated p(cuff,int) for those inflation cycles judged suitable for analysis, and (iii) discarded measurements that were clearly inconsistent with others from the same voiding cycle.
Overall, 689 of the 1,458 ratings (45%) were excluded, with just 4% of all ratings discarded for inconsistency. For 385 of the 486 inflation cycles (79%) there was complete agreement that the cycle should or should not be analyzed. Thereafter, for the 262 inflation cycles analyzed by two or three observers, the overall SD error in measurements of p(cuff,int) was 4.6 cm H(2)O.
We conclude that there is good agreement between experienced observers in their interpretation of data from the cuff test. For practical purposes, there is no need for multiple observers in the clinical application of the cuff method.
No preview · Article · Jan 2003 · Neurourology and Urodynamics
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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.
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.
No preview · Article · Apr 2002 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: 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.
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.
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.
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.
No preview · Article · Jan 2002 · The Journal of Urology
[Show abstract][Hide abstract] ABSTRACT: We present a 37-year-old patient with primary choriocarcinoma arising in the urinary bladder, who received 5 months of intensive chemotherapy with a very good response. He died of a pulmonary embolus before his treatment could be completed. A post-mortem examination revealed extensive necrotic nodules in the lungs and brain. There was only one small focus of viable tumour in the brain. There was no residual tumour in the bladder, and no testicular tumours or scars fulfilling the criteria for a true extragonadal teratoma. It is likely that the origin of the bladder choriocarcinomas is from metaplasia/de-differentiation of a transitional cell carcinoma to the level of trophoblast. Lesser degrees of differentiation producing functional changes in the carcinoma cells with secretion of beta hCG without structural changes are much more common.
No preview · Article · Feb 1996 · Clinical Oncology
[Show abstract][Hide abstract] ABSTRACT: To determine the clinical, symptomatic and objective urodynamic outcome of patients undergoing endoscopic bladder transection.
The study included 20 men and 30 women (mean age of 50 +/- 15 years, range 20-86) who underwent endoscopic bladder transection. Their underlying diagnoses were idiopathic detrusor instability (41), enuresis with instability (6), multiple sclerosis (2) and Parkinson's disease (1). A full-thickness endoscopic transection of the bladder was performed under general anaesthesia. Subjective assessment was performed using symptom scores (0-14 points) and a Visick grading system (group A-E). Objective assessment was carried out using urodynamic studies. The mean follow-up period was 6 years (57 +/- 22 months, range 6-85).
The mean hospital stay was 8 +/- 3 days (range 3-22). No patients died after the operation. Postoperative complications included extra-peritoneal extravasation (2), recurrent urinary tract infection (5) and urethral stricture (1). Symptom scores before and after the operation were 9 +/- 2 (range 4-14) and 8 +/- 3 (range 1-14) points respectively. The overall outcome of the procedure was satisfactory in only eight (16%) patients. The mean duration of symptomatic relief was 17 weeks (range 3-53). There was no significant difference between urodynamic results before and after the operation. Bladder instability observed in all patients before operating was demonstrated in 93% of patients after the operation.
The results of our study suggests that endoscopic bladder transection produces only a transient symptomatic relief in a few of those patients who have failed to respond to pharmacological manipulations. We do not feel that its continued role is justified.
No preview · Article · Jun 1995 · British Journal of Urology