Noninvasive urodynamics: a study of male voiding dysfunction.

A group of 26 patients was tested for isovolumetric pressure and optimal flow rate by means of the cuff-uroflow (CUF) technique. The same patients were also examined in the clinic, and a diagnosis was recorded. The two processes were performed independently in a statistically double-blind manner. Standard statistical comparisons were made, and it was shown that there exists substantial correlation between the results of clinical examination and the cuff-uroflow procedure. It was also shown that the CUF technique converged more rapidly to a correct diagnosis than standard clinical procedures. Surgical treatment and watchful waiting were examined and it was shown, as expected, that surgical treatment resulted in substantial improvement in most cases, but that watchful waiting generated no statistically significant change.

Noninvasive quantitative method for measuring isovolumetric bladder pressure and urethral resistance in the male: I. Experimental validation of the theory.

Noninvasive measurement of intravesical pressure, impulsive flow rate, and localized urethral resistance is achieved by clamping the penis immediately above the glans with a pneumatic cuff and then instructing the patient to initiate voiding. The cuff is then deflated slowly until urinary flow of at least 1 ml/s is detected and is then released rapidly to permit unimpeded flow. Cuff pressure, voided volume, and flow rate are recorded as functions of time. From the resulting tracings it is possible to determine the isovolumetric bladder pressure, the impulsive flow rate, and the flow pattern specific to the test. We studied 53 male patients demonstrating that data thus obtained are reproducible and that the cuff pressure at the initiation of voiding does measure the bladder pressure at this moment. We then modeled the lower urinary tract by an analog electrical circuit which facilitated the analysis of the urodynamic data. This analysis suggests that it is possible to separate the effects of bladder dysfunction from the effects of urethral resistance and to localize the resistance to the proximal or distal urethra without invasive testing.

Objective noninvasive evaluation of benign prostatic hypertrophy.

An objective noninvasive procedure has been developed to evaluate the urodynamics of benign prostatic hypertrophy. The test uses pneumatic occlusive cuffs similar to those used for blood pressure measurements and the electrical engineering concepts of open-circuit, short-circuit, and transient response measurements. The cuff is first inflated to measure pressure, then rapidly released, yielding the transient response and subsequent unimpeded flow. From the pressure and flowrate recordings as functions of time, objective evaluations of bladder strength and urethral obstruction are extracted.

A 12-year experience with enterovesical fistulas.

OBJECTIVES: To review our experience with enterovesical fistulas in order to determine the most accurate diagnostic studies and most effective method of treatment. METHODS: A retrospective record review of 76 patients who were diagnosed and treated for enterovesical fistulas over a 12-year period was performed. Data collection focused on presenting symptoms, urinary disease process, diagnostic studies, and methods of management. RESULTS: Diverticular disease was the primary etiologic factor in the majority of patients (59%), with colonic malignancy, granulomatous bowel disease, and radiation therapy accounting for the majority of the remainder. Cystoscopy (60%) and cystography (44%) were the most sensitive diagnostic studies. There was no statistical difference in the complication rate between groups treated with single or multistage repair. CONCLUSIONS: One-stage repair of enterovesical fistulas can be safely performed when the cause is diverticular or granulomatous bowel disease. Staged repairs may be more judicious in patients with large intervening pelvic abscesses or those in whom advanced malignancy or radiation changes are present.

Effect of terazosin on urine storage and voiding in the aging male with prostatism.

Patients in a private practice, evaluated for prostatism due to benign prostatic hypertrophy were offered the options of medical treatment with the alpha blocker terazosin, surgical treatment, or continued observation. Nineteen men accepted terazosin treatment and are the subjects of the present series. They were treated over a mean period of 8 months, the longest treatment lasting over 22 months. Dosage was started at 1 mg/d and increased as tolerated to 2, 5, and 10 mg/d over the test period. Extensive testing including invasive urodynamics, multiple voiding diaries, and symptoms scores at each dosage level was carried out. We found that flow rates increased moderately from baseline in a dose dependent fashion. At the 10 mg/d dosage some patients achieved flow rates in the low normal range. Patients on treatment documented a decrease in the number of voidings per day, a decrease in nocturia, an increase in bladder capacity and the volume of each voiding. On the other hand, patients frequently did not appreciate changes in their voiding patterns, as reflected in their responses to the symptom questionnaires. We could not demonstrate significant changes in bladder pressures on cystometry either during filling or voiding. Our data suggested that terazosin may well have a direct effect on the fundus of the aging bladder to increase capacity, and, through the well-known relationship between voided volume and flow rate, increase urinary flow rate.

The clinical usefulness of serum prostate specific antigen after hormonal therapy of metastatic prostate cancer.

We longitudinally followed serum prostate specific antigen (PSA) levels in 48 patients who were treated with either orchiectomy, monthly luteinizing hormone-releasing hormone injection or continuous diethylstilbestrol for stage D2 prostate adenocarcinoma and achieved an objective response. Of the patients 34 had clinical evidence of disease progression (median remission duration 19 months). Median length of followup for the 14 patients who remained in remission was 42 months. Pretreatment performance status, pretreatment extent of metastases as measured by a bone scan and post-treatment nadir PSA level were univariately correlated with remission duration. After adjustment for the 2 former pretreatment variables, a highly significant independent effect of the nadir PSA level on remission duration persisted. Patients whose post-treatment nadir PSA level decreased below 4 ng./ml. had a significantly longer remission duration than those whose nadir PSA remained elevated (median 42 versus 10 months, p less than 0.0001). No cases were observed to progress (as defined by our criteria independent of PSA level) while the serial post-treatment PSA levels continued to decrease or remained at a plateau after reaching the nadir. The time at which the PSA began to increase once the nadir was reached predated objective evidence of progression in all patients except 2 in whom the 2 events occurred simultaneously (mean lead time 7.3 +/- 5.0 months). We conclude that following serial PSA levels in patients treated with androgen ablation for metastatic prostate cancer can aid in distinguishing favorable from nonfavorable responders early in the course of therapy and greatly assist in monitoring for progression.

The effects of transurethral resection on the urodynamics of prostatism.

We studied 11 patients urodynamically before and 6 months after transurethral resection of the prostate. Bladder pressures were measured through a fine suprapubic catheter. Urinary stream force and flow rate were measured simultaneously. We calculated values for stream velocity, area of Schäfer's flow control zone, the vena contracta, stream energy loss, total bladder work, total stream power and the passive urethral resistance relationship. After prostatic resection improved voiding was documented in most physiological parameters. However, the total work capacity of the bladder remained constant and appeared to be a fixed property of the healthy bladder. An increase in the volume voided postoperatively was related to an increase in the bladder capacity associated with a decrease in detrusor instability, and was not related to a decrease in residual urine.

Urinary flow velocity as an index of male voiding function.

Urinary velocity and urinary peak flow rate developed by 463 male patients were measured before and after treatment for prostatic obstruction, stricture or prostatitis and compared to 121 documented normal males. It was shown that peak flow rate does discriminate partially between the normal and non-normal populations, but that many subjects who presented with ostensibly normal flow rates were actually obstructed when measured by peak urinary velocity. Velocity is shown to be a valuable secondary measurement in the clinic, and the flow velocity vs. flow rate diagram is demonstrated to be a good tool for classifying patients urodynamically.

Urodynamic norms in women. I. Normals versus stress incontinents.

Urodynamic statistics for normal women were compared to similar norms for stress incontinent women. It was concluded that 1) the reduction of flow rate in stress incontinent patients appears to be the result, with high probability of pathologic changes in the function of the distal urethra, 2) stress incontinence does not affect the combined effects of bladder pressure and the proximal urethral resistance during voiding as reflected in velocity, 3) the distal urethral cross-sectional area appears to be under neuromuscular control and 4) the distal urethra of stress incontinent women appears to be incapable of opening as widely as the distal urethra of normal women. It is not currently possible to assign anatomical or physiological causes to the observed phenomena.

New techniques for the evaluation of bladder function.

The various techniques available for the dynamic assessment of bladder function, including uroflowmetry, cystometrography, urethral closure pressure profiles, and sphincteric electromyography are presented. All of these approaches are discussed in terms of the indications for their use and their functions in evaluation.

Comparison of cystometrograms and urethral profiles with gas and water media.

Twenty-five female patients were studied using both gas and water media for custometrograms and urethral profiles. The results showed that gas and water did not generate equivalent data in either cystometrograms or urethral profiles. The cystometrogram data showed a high correlation of data between gas and water, with gas values consistently lower than water values. Urethral profile data with gas were very difficult to interpret in terms of water-generated data, and correlations were tenuous at best.

Urodynamics.

The urinary tract is a hydrodynamic system whose components are in precise balance with each other and whose functioning depends on mechanical equilibrium. Alteration of the delicate balance between bladder and urethra means dysfunction in voiding or continence. Of greatest clinical interest at present is the bladder-urethra matching mechanism, which controls normal or abnormal voiding or continence. Since the matching combination of bladder and urethra must obey the same hydrodynamic laws that govern all fluid systems, it is obvious that measurement of fluid quantities and fluid porperties should correlate with function and dysfunction in the system. Urodynamics is the art of developing standard fluid-mechanical techniques that will be useful in routine clinical evaluation. Increasing experience with diagnostic urodynamic tests nurtures non-invasive, precise diagnosis of voiding dysfunction. Inexpensive, readily available and convenient techniques have been developed and are in clinical use. We can look forward to many more.