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.

A nomogram to classify men with lower urinary tract symptoms using urine flow and noninvasive measurement of bladder pressure.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

An automated penile compression release maneuver as a noninvasive test for diagnosis of bladder outlet obstruction.

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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). CONCLUSIONS: 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.

Noninvasive measurement of bladder pressure. Does mechanical interruption of the urinary stream inhibit detrusor contraction?

PURPOSE: 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. MATERIALS AND METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

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.

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.

A simple resolution procedure using the Staudinger reaction for the preparation of P-stereogenic phosphine oxides.

The resolution of a variety of (+/-)-P-stereogenic phosphines is achieved by exploiting the Staudinger reaction of a (+/-)-phosphine with enantiopure (1S,2R)-O-(tert-butyldimethylsilyl)isobornyl-10-sulfonyl azide. The resulting mixtures of diastereomeric phosphinimines are generally separable by fractional crystallization or flash chromatography. Subsequent acid-catalyzed hydrolysis provides the corresponding optically pure phosphine oxides in high yields.

Is there a simpler method for predicting lower pole stone clearance after shockwave lithotripsy than measuring infundibulopelvic angle?

BACKGROUND AND PURPOSE: Several anatomic factors influence the clearance of lower pole stones treated with shockwave lithotripsy (SWL). One of these is the infundibulopelvic angle, but its measurement is complex. METHODS: We proposed a more simple measure of caliceal dependence, the caliceal pelvic height (CPH), which we defined as the distance between a horizontal line from the lowermost point of the calix containing the stone to the highest point of the lower lip of the renal pelvis. RESULTS: In 62 patients who had SWL for solitary lower pole stones, a CPH < 15 mm was associated with a stone clearance rate of 92%, whereas with a CPH > or = 15 mm, the clearance rate was only 52% (p < 0.05). A majority (74%) of the patients with an infundibular width of > or = 5 mm were rendered stone free compared with 40% of those with a width of < 5 mm (p < 0.05). CONCLUSION: Measurement of the CPH, in conjunction with other anatomic factors, may more accurately predict the outcome of SWL in patients with lower pole stones.

Primary in situ extracorporeal shock wave lithotripsy in the management of ureteric calculi: results with a third-generation lithotripter.

OBJECTIVE: To review the results of primary in situ extracorporeal shock wave lithotripsy (ESWL) for the treatment of ureteric stones using a third-generation lithotripter, the Dornier MFL 5000 (Dornier Medizentechnic, Germany). PATIENTS AND METHODS: The study comprised a retrospective review of treatment outcome in 180 patients with 196 stones who were treated with primary in situ ESWL, assessing the success of this approach and establishing reasons for failure. RESULTS: At the 3-month follow-up, 88% of patients were stone-free; 21 patients failed ESWL and were treated by ureteroscopic stone extraction with no complications. Stone-free rates were 90% for upper ureteric, 89% for middle-third and 86% for lower-third calculi. Twenty-one patients required auxiliary procedures in the form of JJ stenting or nephrostomy. Failure of ESWL was associated with stone size (>1.3 cm) but not location or inadequate treatment. CONCLUSION: Where prompt access to ESWL is available, primary in situ ESWL remains an effective form of treatment for all ureteric calculi, although stone-free rates are lower for larger stones.

Primary choriocarcinoma of the urinary bladder: a case report.

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.

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.

Outcome of endoscopic bladder transection.

OBJECTIVE: To determine the clinical, symptomatic and objective urodynamic outcome of patients undergoing endoscopic bladder transection. PATIENTS AND METHODS: 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). RESULTS: 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. CONCLUSION: 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.

Bladder function in healthy volunteers: ambulatory monitoring and conventional urodynamic studies.

OBJECTIVE: To obtain data on conventional artificial filling cystometry and ambulatory monitoring in healthy asymptomatic control populations. SUBJECTS AND METHODS: Seventeen healthy volunteers were assessed by means of artificial filling cystometry (CMG), filling at rates of 50 ml/min (CMG 50) and 100 ml/min (CMG 100), and ambulatory monitoring (AM). RESULTS: Significant differences were found between AM and CMG with respect to: the pressure rise on filling (P < 0.02), voided volumes (P < 0.01) and maximum detrusor pressure on micturition (P < 0.01). Detrusor instability was found in 38% of volunteers on AM, in 17% on CMG 50, but in none on CMG 100. CONCLUSION: A range of baseline urodynamic values has been established which could provide the basis for future studies of ambulatory monitoring.

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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.

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.

Ambulatory monitoring and electronic measurement of urinary leakage in the diagnosis of detrusor instability and incontinence.

The ability of conventional artificial filling urodynamic studies (CMG) and ambulatory monitoring during natural bladder filling (AM) to detect phasic detrusor activity (detrusor instability) and incontinence was studied in 52 patients suspected on clinical grounds of having bladder dysfunction, but in whom a CMG had not provided an adequate explanation of their symptoms. Detrusor instability (DI) was found on AM in 31 patients who were not unstable on conventional CMG using the criteria of the International Continence Society: DI was diagnosed on filling in 20 patients and on provocation in a further 11. Incontinence was demonstrated by electronic nappy testing in 23 patients: 13 had urge incontinence due to DI, 7 had genuine stress incontinence alone and 3 had both genuine stress incontinence and detrusor instability. Thus DI was diagnosed significantly more frequently by AM than by CMG. Ambulatory monitoring was more sensitive in the diagnosis of instability and incontinence and it may prove to be a valuable aid in the diagnosis of bladder dysfunction not detected during conventional cystometry.