0022-5347/79/1215-0643$02.00/0 Vol. 121, May Printed in U.S.A.
THE JOURNAL OF UROLOGY
Copyright © 1979 by The Williams & Wilkins Co.
URODYNAMIC TESTING: ALTERNATIVES TO ELECTRONICS FRANK HINMAN, JR.* From the Division of Urology, University of California School of Medicine, San Francisco, California
ABSTRACT
Electronic urodynamic testing, including bladder pressure, urethral pressure profile, voiding rate and velocity, and electromyography, is expensive in terms of equipment, operator and time. Clinical urodynamic testing, including voiding habits and timing, bladder capacity, residual urine volume, voiding cystography, cystometrography and neurologic evaluation, is readily done in the office. Analysis of common syndromes requiring urodynamic assay shows that clinical urodynamic testing may be more useful than electronic urodynamic testing for appropriate treatment. Urodynamic studies done in research centers since 1954 have provided the practicing urologist with an understanding of the events of normal micturition and of the variations induced by lower urinary tract disorders. The clinician now is able to interpret the diagnostic studies performed in his office (without complex instrumentation) in terms of urodynamic function. Herein is compared for the several syndromes necessitating urodynamic assay the readily available diagnostic methods to those requiring sophisticated and costly instrumentation. The results of the tests are related to available therapy. For the sake of discussion urodynamic testing with electronic equipment is termed electronic urodynamic testing. It includes determinations of bladder pressure, intra-abdominal pressure, urethral pressure profile, voiding rate and velocity, and electromyography. It requires expensive, delicate equipment, an experienced, conscientious operator and time. On the other hand, urodynamic testing that may be done in the office is termed clinical urodynamic testing. CLINICAL URODYNAMIC TESTING VERSUS ELECTRONIC URODYNAMIC TESTING
Should electronic urodynamic testing be part of the regular urologic practice or should it be reserved for special problems and be performed by specialists? Clinically, there is little use in measuring something that can neither be applied to diagnosis nor treated. This situation contrasts with that in research, in which case data on populations are essential to an understanding of the physiopathologic processes. Furthermore, exactness in measurements is a waste when individual variations from patient to patient and from time to time in the same patient are the rule. Finally, if the instrumentation affects the responses, either psychologically or physically (hydraulically), the error may well exceed the range of true response. Basically, what one needs to know is: 1) how much the bladder holds at normal pressure, 2) what pressure it generates to empty, 3) whether the urethra functions reciprocally, 4) how free the flow is, 5) whether voiding is complete and 6) whether the act is controlled and coordinated. For electronic urodynamic testing these questions are translated into: 1) resting bladder pressure and capacity, 2) maximum bladder pressure, 3) urethral pressure profile, 4) urine flow rate and velocity, 5) residual urine volwne and 6) electromyography (table 1). One may well ask whether the same information can be Accepted for publication July 21, 1978. Read at annual meeting of American Urological Association, Washington, D. C., May 21-25, 1978. * Requests for reprints: Urology M-553, University of California School of Medicine, San Francisco, California 94143.
obtained from clinical urodynamic testing (table 1). The diagnostic study of a patient with voiding abnormalities begins with an alertly obtained history and, of course, urinalysis and some estimate of renal function. The stream is observed and voiding is timed by a stopwatch or other means. Next, bladder capacity is estimated, perhaps by asking the patient, and residual urine volwne is determined by a phenolsulfonphthalein excretion test, excretory urography or direct catheterization. In many cases a limited neurologic examination (including at least anal tone, perineal sensation and bulbocavernosus reflex) is indicated. Much information can be gained easily by having the patient record time and volume of voidings for 1 or 2, 24-hour periods. After these non-instrumental steps cystometrography (with or without stimulation with bethanechol chloride and using a simple water manometer) will provide information on bladder capacity and often detrusor pressure, as well as reveal difficulties with inhibition. If indicated a voiding cystourethrogram may be obtained with the same filling, followed by panendoscopy. Selections from the few drug groups with specific actions may be administered and their relative effectiveness may confirm the findings obtained in the diagnostic studies. The principal part of the diagnostic study, including the cystometrogram, may be done in the office on the first visit. The total cost to the patient in time and discomfort is modest. It is possible that the greatest errors result from skipping over these basic clinical studies and relying on electronic instruments to provide the solution. Electronic urodynamic testing may supplement the basic studies but it cannot substitute for them. CATEGORIES OF DISORDERS REQUIRING EVALUATION
Only a few categories of micturition disorders concern the clinician in each of the 3 classes of patients: men, women and children (table 2). In men post-prostatectomy stress incontinence and prostatic obstruction are the chief problems. Stress and urgency incontinence form the majority of the problems in women but incoordination disorders are not rare. In children incoordination with wetting and enuresis compose the largest group and in a few boys obstruction from valves and strictures are disorders needing urodynamic testing. Neurologic disorders, although less often seen in practice, occur in all 3 classes of patients. RESULTS
When the actual problems encountered by the urologist in his practice (in contrast to research studies and investigation of rare or complicated disorders) are considered the value of the usual diagnostic studies discussed previously can be compared to the more complex one. Since intermittent female incontinence is probably the most
643
644
HINMAN TABLE
Parameter
1. Electronic urodynamic testing versus clinical urodynamic testing Electronic Urodynamic Testing Clinical Urodynamic Testing
Integrated functions: Vesical resting pressure
Historical data Capacity, cystometrogram, voiding cystourethrogram Voiding cystourethrogram (trabeculation), cystometrogram Cystometrogram with bethanechol chloride
Bladder and abdominal pressure
Maximum pressure Abnormal contraction responses
Urethral pressure profile
Urethral function: Flow Force Myoneural coordination
TABLE
Timed void, observed stream, residual urine determination Timed void, observation of stream Cast distance Bulbocavernosus reflex, perinea! sensation, observed stream, residual urine determination
Flow rate Exit velocity Electromyogram
2. Categories of common disorders of micturition
Men
Women
Stress incontinence
Stress incontinence Urge incontinence Incoordination disorders
Obstruction Neurogenic
Bladder pressure with bethanechol chloride
Neurogenic
TABLE
3. Intermittent female incontinence
Children
Wetting and enuresis, giggle incontinence Valves, congenital strictures Neurogenic
common problem needing evaluation the urodynamic findings in stress incontinence are compared to the 2 disorders with which it could be confused: urgency incontinence and neurogenic bladder (table 3). Each disorder has its characteristic pattern of positive findings, so that it does not have to be segregated with the help of a computer. For example, when carefully questioned the patient will describe the time, and the activities and sensations accompanying the leakage. She may report frequency and urgency or related precipitant total voiding. The neurologic examination and cystometrogram will differentiate structural from nerve abnormalities, and observation of the perineum upon stress and examination of the urethra and bladder will further distinguish these causes of incontinence. Determination of the bladder and rectal pressure with urethral pressure profile probably will provide a better basis for management only in the few cases that fall between these patterns. Problems of incontinence after a vaginal operation and certain complex mixtures of stress and urgency incontinence do require electronic urodynamic testing to identify precisely the factors involved and to plan the course of treatment. However, these situations are rare in practice and even the most accurate and detailed electronic instrumentation may not help in the actual management and treatment. Incoordinated bladder function is another rather common problem. In male patients 3 causes exist: 1) obstructive, 2) neuropathic or 3) psychogenic abnormalities. These 3 groups were separated by the standard steps (table 4). Probably no additional clinically useful information would be gained from electronic urodynamic testing. In women and children the uncoordinated bladder syndromes are more complex but a few simple steps will separate the psychologic from the neurogenic (table 5). As usual, the history is most revealing if psychodynamic factors are kept in mind, and if the neurologic examination and stimulated cystometrogram give positive findings. Furthermore, information from the usual tests of determination of residual urine and observation of bladder and urethral configuration on voiding cystography, when added to the basic diagnostic study, allow rational treatment (table 6). Obstruction in the male patient seldom needs urodynamic assessment. Maximum flow rate is a useful measure of progression but a description by the patient and observation of the stream are quite adequate for non-research purposes since one does not operate solely on the basis of flow rate. Residual
Stress Incontinence
Urgency Incontinence
Neurogenic Bladder
+ + +
+ + +
0
0
+ + + +
0 0
+ +
History Capacity Residual urine Neurologic examination Volume/time record Cystometrography Voiding cystourethrography Panendoscopy Pharmacologic manipulation
+
0
+
0 +
0
+
+ (with bethanechol chloride) 0 0
0
+ -positive; 0-negative or not necessary. TABLE
4. lncoordinated bladder in men 0 bstructive
Neurogenic
Psychogenic
+ + +
0
+ + +
History Observed stream Timed void Neurologic examination Volume/time record Cystometrography
+ + + + +
0
+ 0
0
+ 0
(with bethanechol chloride)
+ + -positive, 0-negative or not necessary.
Panendoscopy
TABLE
+
0
5. lncoordinated bladder in women and children Psychologi- Neurogenic cal
History Neurologic evaluation Cystometrography (with bethanechol chloride)
+
0
0
+
0
+
+ -positive; 0-negative or not necessary. TABLE
6. Available treatment modalities Effect Desired
Detrusor
Relax
Vesical neck
Stimulate Relax Stimulate
External sphincter
Relax Stimulate
Modality Cholinergic blockade, nerve division, psychotherapy Cholinergic stimulation a-Adrenergic blockade, resection of vesical neck, psychotherapy a-Adrenergic stimulation, urethrovesical suspension and so forth Central, somatic block, resection Electronic stimulator, prosthesis
urine volume is probably a more useful guide to vesical decompensation and, hence, to the need for operation. TREATMENT AVAILABLE AFTER URODYNAMIC DIAGNOSIS
A limitation on the value of exact and detailed urodynamic measurement- of equal importance to the limitation imposed
645
URODYNAMIC TESTING
upon it by the difficulties of instrumentation and reproducibility- is that only a few modalities of treatment are available when the results are available (table 6). Detrusor activity may be decreased by drugs or operation and increased by medication. The vesical neck mechanism is relaxed by psychotherapy if hold-up is central, by a-adrenergic blockade if it is from local reflexes and by surgical resection if it is (rarely) structural. This mechanism is tightened by drugs, surgical suspension or revision. The active external sphincter may be relaxed by psychotherapy or nerve blockade or by actual resection, while it may be stimulated electronically or supplanted by a prosthesis. The role of any urodynamic assessment, then, is to allow selection of the most effective modality. Since there are relatively few to choose from extreme precision in urodynamic testing does not yield proportionate therapeutic dividends.
CONCLUSIONS
Sales of complicated and expensive electronic equipment for urodynamic testing throughout the country have increased geometrically in the last few years and urodynamic tests are being billed for and given code numbers. Concern is expressed that 1) a reading may be substituted for clinical evaluation when the reliability and significance of the measurement are in doubt, 2) the real uses of skillful urodynamic study in problem cases may be rejected as disillusionment is felt about the value of these tests for routine clinical evaluation and 3) costs to patients increase to cover clinicians' investment in time and instruments and, possibly, from overuse of remunerative facilities. Hopefully, urologists will restrict electronic urodynamic testing to those cases not solvable by standard clinical tests and to those centers with the time and expertise to provide reliable solutions.
THE JOURNAL OF UROLOGY
Copyright © 1979 by The Williams & Wilkins Co.
URODYNAMIC TESTING: ALTERNATIVES TO ELECTRONICS FRANK HINMAN, JR.* From the Division of Urology, University of California School of Medicine, San Francisco, California
ABSTRACT
Electronic urodynamic testing, including bladder pressure, urethral pressure profile, voiding rate and velocity, and electromyography, is expensive in terms of equipment, operator and time. Clinical urodynamic testing, including voiding habits and timing, bladder capacity, residual urine volume, voiding cystography, cystometrography and neurologic evaluation, is readily done in the office. Analysis of common syndromes requiring urodynamic assay shows that clinical urodynamic testing may be more useful than electronic urodynamic testing for appropriate treatment. Urodynamic studies done in research centers since 1954 have provided the practicing urologist with an understanding of the events of normal micturition and of the variations induced by lower urinary tract disorders. The clinician now is able to interpret the diagnostic studies performed in his office (without complex instrumentation) in terms of urodynamic function. Herein is compared for the several syndromes necessitating urodynamic assay the readily available diagnostic methods to those requiring sophisticated and costly instrumentation. The results of the tests are related to available therapy. For the sake of discussion urodynamic testing with electronic equipment is termed electronic urodynamic testing. It includes determinations of bladder pressure, intra-abdominal pressure, urethral pressure profile, voiding rate and velocity, and electromyography. It requires expensive, delicate equipment, an experienced, conscientious operator and time. On the other hand, urodynamic testing that may be done in the office is termed clinical urodynamic testing. CLINICAL URODYNAMIC TESTING VERSUS ELECTRONIC URODYNAMIC TESTING
Should electronic urodynamic testing be part of the regular urologic practice or should it be reserved for special problems and be performed by specialists? Clinically, there is little use in measuring something that can neither be applied to diagnosis nor treated. This situation contrasts with that in research, in which case data on populations are essential to an understanding of the physiopathologic processes. Furthermore, exactness in measurements is a waste when individual variations from patient to patient and from time to time in the same patient are the rule. Finally, if the instrumentation affects the responses, either psychologically or physically (hydraulically), the error may well exceed the range of true response. Basically, what one needs to know is: 1) how much the bladder holds at normal pressure, 2) what pressure it generates to empty, 3) whether the urethra functions reciprocally, 4) how free the flow is, 5) whether voiding is complete and 6) whether the act is controlled and coordinated. For electronic urodynamic testing these questions are translated into: 1) resting bladder pressure and capacity, 2) maximum bladder pressure, 3) urethral pressure profile, 4) urine flow rate and velocity, 5) residual urine volwne and 6) electromyography (table 1). One may well ask whether the same information can be Accepted for publication July 21, 1978. Read at annual meeting of American Urological Association, Washington, D. C., May 21-25, 1978. * Requests for reprints: Urology M-553, University of California School of Medicine, San Francisco, California 94143.
obtained from clinical urodynamic testing (table 1). The diagnostic study of a patient with voiding abnormalities begins with an alertly obtained history and, of course, urinalysis and some estimate of renal function. The stream is observed and voiding is timed by a stopwatch or other means. Next, bladder capacity is estimated, perhaps by asking the patient, and residual urine volwne is determined by a phenolsulfonphthalein excretion test, excretory urography or direct catheterization. In many cases a limited neurologic examination (including at least anal tone, perineal sensation and bulbocavernosus reflex) is indicated. Much information can be gained easily by having the patient record time and volume of voidings for 1 or 2, 24-hour periods. After these non-instrumental steps cystometrography (with or without stimulation with bethanechol chloride and using a simple water manometer) will provide information on bladder capacity and often detrusor pressure, as well as reveal difficulties with inhibition. If indicated a voiding cystourethrogram may be obtained with the same filling, followed by panendoscopy. Selections from the few drug groups with specific actions may be administered and their relative effectiveness may confirm the findings obtained in the diagnostic studies. The principal part of the diagnostic study, including the cystometrogram, may be done in the office on the first visit. The total cost to the patient in time and discomfort is modest. It is possible that the greatest errors result from skipping over these basic clinical studies and relying on electronic instruments to provide the solution. Electronic urodynamic testing may supplement the basic studies but it cannot substitute for them. CATEGORIES OF DISORDERS REQUIRING EVALUATION
Only a few categories of micturition disorders concern the clinician in each of the 3 classes of patients: men, women and children (table 2). In men post-prostatectomy stress incontinence and prostatic obstruction are the chief problems. Stress and urgency incontinence form the majority of the problems in women but incoordination disorders are not rare. In children incoordination with wetting and enuresis compose the largest group and in a few boys obstruction from valves and strictures are disorders needing urodynamic testing. Neurologic disorders, although less often seen in practice, occur in all 3 classes of patients. RESULTS
When the actual problems encountered by the urologist in his practice (in contrast to research studies and investigation of rare or complicated disorders) are considered the value of the usual diagnostic studies discussed previously can be compared to the more complex one. Since intermittent female incontinence is probably the most
643
644
HINMAN TABLE
Parameter
1. Electronic urodynamic testing versus clinical urodynamic testing Electronic Urodynamic Testing Clinical Urodynamic Testing
Integrated functions: Vesical resting pressure
Historical data Capacity, cystometrogram, voiding cystourethrogram Voiding cystourethrogram (trabeculation), cystometrogram Cystometrogram with bethanechol chloride
Bladder and abdominal pressure
Maximum pressure Abnormal contraction responses
Urethral pressure profile
Urethral function: Flow Force Myoneural coordination
TABLE
Timed void, observed stream, residual urine determination Timed void, observation of stream Cast distance Bulbocavernosus reflex, perinea! sensation, observed stream, residual urine determination
Flow rate Exit velocity Electromyogram
2. Categories of common disorders of micturition
Men
Women
Stress incontinence
Stress incontinence Urge incontinence Incoordination disorders
Obstruction Neurogenic
Bladder pressure with bethanechol chloride
Neurogenic
TABLE
3. Intermittent female incontinence
Children
Wetting and enuresis, giggle incontinence Valves, congenital strictures Neurogenic
common problem needing evaluation the urodynamic findings in stress incontinence are compared to the 2 disorders with which it could be confused: urgency incontinence and neurogenic bladder (table 3). Each disorder has its characteristic pattern of positive findings, so that it does not have to be segregated with the help of a computer. For example, when carefully questioned the patient will describe the time, and the activities and sensations accompanying the leakage. She may report frequency and urgency or related precipitant total voiding. The neurologic examination and cystometrogram will differentiate structural from nerve abnormalities, and observation of the perineum upon stress and examination of the urethra and bladder will further distinguish these causes of incontinence. Determination of the bladder and rectal pressure with urethral pressure profile probably will provide a better basis for management only in the few cases that fall between these patterns. Problems of incontinence after a vaginal operation and certain complex mixtures of stress and urgency incontinence do require electronic urodynamic testing to identify precisely the factors involved and to plan the course of treatment. However, these situations are rare in practice and even the most accurate and detailed electronic instrumentation may not help in the actual management and treatment. Incoordinated bladder function is another rather common problem. In male patients 3 causes exist: 1) obstructive, 2) neuropathic or 3) psychogenic abnormalities. These 3 groups were separated by the standard steps (table 4). Probably no additional clinically useful information would be gained from electronic urodynamic testing. In women and children the uncoordinated bladder syndromes are more complex but a few simple steps will separate the psychologic from the neurogenic (table 5). As usual, the history is most revealing if psychodynamic factors are kept in mind, and if the neurologic examination and stimulated cystometrogram give positive findings. Furthermore, information from the usual tests of determination of residual urine and observation of bladder and urethral configuration on voiding cystography, when added to the basic diagnostic study, allow rational treatment (table 6). Obstruction in the male patient seldom needs urodynamic assessment. Maximum flow rate is a useful measure of progression but a description by the patient and observation of the stream are quite adequate for non-research purposes since one does not operate solely on the basis of flow rate. Residual
Stress Incontinence
Urgency Incontinence
Neurogenic Bladder
+ + +
+ + +
0
0
+ + + +
0 0
+ +
History Capacity Residual urine Neurologic examination Volume/time record Cystometrography Voiding cystourethrography Panendoscopy Pharmacologic manipulation
+
0
+
0 +
0
+
+ (with bethanechol chloride) 0 0
0
+ -positive; 0-negative or not necessary. TABLE
4. lncoordinated bladder in men 0 bstructive
Neurogenic
Psychogenic
+ + +
0
+ + +
History Observed stream Timed void Neurologic examination Volume/time record Cystometrography
+ + + + +
0
+ 0
0
+ 0
(with bethanechol chloride)
+ + -positive, 0-negative or not necessary.
Panendoscopy
TABLE
+
0
5. lncoordinated bladder in women and children Psychologi- Neurogenic cal
History Neurologic evaluation Cystometrography (with bethanechol chloride)
+
0
0
+
0
+
+ -positive; 0-negative or not necessary. TABLE
6. Available treatment modalities Effect Desired
Detrusor
Relax
Vesical neck
Stimulate Relax Stimulate
External sphincter
Relax Stimulate
Modality Cholinergic blockade, nerve division, psychotherapy Cholinergic stimulation a-Adrenergic blockade, resection of vesical neck, psychotherapy a-Adrenergic stimulation, urethrovesical suspension and so forth Central, somatic block, resection Electronic stimulator, prosthesis
urine volume is probably a more useful guide to vesical decompensation and, hence, to the need for operation. TREATMENT AVAILABLE AFTER URODYNAMIC DIAGNOSIS
A limitation on the value of exact and detailed urodynamic measurement- of equal importance to the limitation imposed
645
URODYNAMIC TESTING
upon it by the difficulties of instrumentation and reproducibility- is that only a few modalities of treatment are available when the results are available (table 6). Detrusor activity may be decreased by drugs or operation and increased by medication. The vesical neck mechanism is relaxed by psychotherapy if hold-up is central, by a-adrenergic blockade if it is from local reflexes and by surgical resection if it is (rarely) structural. This mechanism is tightened by drugs, surgical suspension or revision. The active external sphincter may be relaxed by psychotherapy or nerve blockade or by actual resection, while it may be stimulated electronically or supplanted by a prosthesis. The role of any urodynamic assessment, then, is to allow selection of the most effective modality. Since there are relatively few to choose from extreme precision in urodynamic testing does not yield proportionate therapeutic dividends.
CONCLUSIONS
Sales of complicated and expensive electronic equipment for urodynamic testing throughout the country have increased geometrically in the last few years and urodynamic tests are being billed for and given code numbers. Concern is expressed that 1) a reading may be substituted for clinical evaluation when the reliability and significance of the measurement are in doubt, 2) the real uses of skillful urodynamic study in problem cases may be rejected as disillusionment is felt about the value of these tests for routine clinical evaluation and 3) costs to patients increase to cover clinicians' investment in time and instruments and, possibly, from overuse of remunerative facilities. Hopefully, urologists will restrict electronic urodynamic testing to those cases not solvable by standard clinical tests and to those centers with the time and expertise to provide reliable solutions.
![[Indication for urodynamic testing].](/assets/img/hold.png)
