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Video urodynamics
VIDEO URODYNAMICS GEORGE D . WEBSTER, M .B ., F.R.C.S. ROBERT A . OLDER, M .D. From the Division of Urology and the Department of Radiology, Duke University Medical Center, Durham, North Carolina
ABSTRACT - Video urodynamics is a technique utilizing synchronously recorded urodynamic studies and cystourethrography for the evaluation of complex lower urinary tract problems . The technique and equipment used in approximately 900 consecutive studies is reported . The value of this method in the investigation of urinary incontinence, complex bladder outlet obstructive states, and neurogenic bladder in particular is presented .
During the past year 926 video-urodynamic studies have been performed for the investigation of a wide variety of lower urinary tract problems . Our technique is based on that originally described by Tanagho et al . in 1966,' which was subsequently put to wide clinical use by the Middlesex group in London, England . 2-5 Our studies have been modified from that described by Bates et al." to include sphincter electromyography and urethral pressure profilometry . Video-urodynamic studies comprise the performance of pre ssure/flow/electromyographic (EMG) studies of the lower urinary tract together with synchronous cystourethrography . We believe that the added sophistication of monitoring subtracted bladder pressure (detrusor pressure) is desirable, particularly for the identification of subtle detrusor instability states and for all micturition studies . The further addition of sphincter EMG monitoring in our hands has been found to be of value only in the evaluation of patients with neurogenic disease, and we now advocate routine performance of EMG studies only in those cases in which pathology of this nature is suspected . We believe that voiding studies are more widely indicated than currently practiced as we have found voiding dysfunction to go frequently hand in hand with bladder storage problems . Urethral pressure profilometry is performed extensively, and characteristic changes with different lower urinary tract problems have been reported . 106
However, we have found profilometry to be the least valuable and most inconsistently diagnostic aspect of our study . Cystourethrography for the identification of voiding dysfunction is used frequently, but is subject to misinterpretation, because changes in the appearance of the outflow tract can be interpreted meaningfully only if measurement of urine flow rate and detrusor pressure are obtained at the time the changes occurred . The combination of urodynamic and cystourethrographic techniques by the method to be later described overcomes these shortcomings, is indispensible for the evaluation of the more difficult urinary tract dysfunctions, and adds a new dimension to their investigation . Apparatus Figure 1 schematically depicts our equipment and its interconnections . There are three basic components, namely, urodynamic equipment, x-ray equipment, and video recording apparatus . Urodynamic equipment A Life-Tech Urolab 1154*, four-channel instrument capable of the simultaneous recording of rectal pressure, external sphincter EMG, subtracted bladder pressure, and total bladder pressure is used . The first rectal pressure "Life-Tech, Urulab, Houston, Texas .
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channel is modular allowing for the switch-over to flow rate during the voiding study . The Urolab 1154 also allows measurement of urethral pressure profile and carbon dioxide cystometry, which is used infrequently . External sphincter EMG is, in addition, monitored by a Life-Tech 9000 EMG oscilloscope with audio . Urine flow rate during voiding is measured by the load cell principle which records urine flow rate and total volume voided . Fluoroscopy of voiding demands that micturition be performed in the erect position, and for this, a simple funnel shaped to fit the female perineum is utilized . 3 X-ray equipment
The study is performed on a standard Picker tilting x-ray table with fluoroscopic capability . The fluoroscopic image is transmitted via a Shintron special effects generator to a standard 19-inch television monitor . The Shintron special effects generator splits the television monitor screen in two, allowing display of the fluoroscopic image on the right side of the screen, the other half displaying the television recorded image from urodynamic chart strip recording . Video recording apparatus
A G.B.C . closed circuit low-light television camera is appropriately positioned to photograph continuously the urodynamic chart strip recording . This image is projected through the Shintron special effects generator to the left side of the television monitor. Hence, at any one time one can see on the video screen the graphic urodynamic study together with the simultaneous fluoroscopic appearance of the bladder and outlet . A permanent record of the study seen on the television monitor is obtained using a Sony video cassette recording device . Physician commentary during the study is recorded, greatly facilitating the understanding of the study during later playback . Fluoroscopic screening time is limited generally to a total of approximately one minute, and radiation exposure is estimated as equivalent to that of a single intravenous pyelogram series . Personnel
The urodynamic facility is staffed by a fulltime physician's assistant and a nurse, physician supervision and interpretation of all studies being accomplished. UROLOGY
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JULY 1980
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VOLUME XVI,
NUMBER I
Image intensifier
Life Tech Urolob ,-~
1154
UPP./CO Z Cystometer Pressure/Flow EMG Pressure Pressure
Life Tech 9000 EMS Oscilloscope and Audio
Shintron - Special Effects Generator 19"Television Monitor
FIGURE
1.
Schematic
drawing of equipment; note central role of special effects generator allowing
simultaneous projection of video appearance and urodynamic changes .
chart
strip
Sony -Videotape Recorder
Technique We attempt to evaluate completely bladder and sphincter function urodynamically and fluoroscopically during the phases of bladder filling, storage, and voiding . This study takes approximately one hour to perform, compromises an initial urine free flow rate prior to instrumentation, followed by continuous monitoring of rectal pressure, sphincter EMG, total bladder pressure, and subtracted bladder pressure during filling and storage phases . During voiding, urine flow rate is, in addition, monitored. Fluoroscopic video cystourethrography is performed intermittently during filling and storage phases, and generally the entire voiding 107
act is screened . At the completion of this study, urethral pressure profilometry is performed either singly or with varying degrees of bladder fullness and in varying postures . Rectal pressure is measured using a fluidfilled balloon constructed from a finger-stall fixed over a length of intravenous tubing . Care is taken to place it above the level of the sphincter to avoid artifact, and overdistention is avoided since it appears to stimulate rectal contractions . Intravesical pressure is measured using a perforated length of 1 .52 mm . O .D . (0 .86 mm . I.D .) polyethylene tubing, passed per urethra alongside the 12 F filling catheter . This tubing has been found to be of the correct consistency to allow for easy insertion and is kink-proof. Two electrodes of 39-gauge plastic-coated wire, the ends of which have been denuded of insulation for 0 .5 cm ., are introduced through a 27-gauge needle into an electrically active portion of the sphincter under oscilloscope control . We customarily place the electrodes in the anterolateral aspect of the external anal sphincter ; however, in suspected neurogenic dysfunction, they are placed directly into the external urethral sphincter by a transperineal route in the male and paraurethral insertion in the female . It is important to immobilize the wires completely by taping their entire length to the skin, for movement and bumping cause artifact . Voluntary control of sphincter activity and the bulbocavernosus reflex are tested prior to commencing the filling study . Filling cystometry using Cystografin solution (14%) is performed with patient in the supine position on the fluoroscopy table . A fast fill rate of 100 cc ./min . is used in adults, the rate being decreased in pediatric patients and neurogenic hyperreflexic bladders . We believe that a normal stable bladder will remain so regardless of the circumstances of filling, and that every attempt should he made to provoke the bladder to act in an unstable manner . Such provocation includes the use of rapid fill rates, stress, posture change, and the use of contrast medium at room temperature . Fluoroscopic screening during the filling study is brief to demonstrate bladder contour, presence or absence of reflux, and the competence of the outflow tract during stress . Filling is continued until the patient is uncomfortably full, when he is tipped into the upright position on the tilting fluoroscopy table and positioned rapidly to allow for oblique half-lateral fluoroscopic screen-
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ing of the bladder and outlet . The filling catheter is removed, the flow meter positioned, and the transducers leveled to the symphysis pubis and monitoring continued . On changing to the erect position there should he no increase in substracted bladder pressure ; however, a marked increase in intravesical pressure will be apparent due to the effect of the weight of abdominal viscera and abdominal muscle contraction on the bladder . Fluoroscopic screening of the bladder in this erect, half-lateral position should show competence of the bladder neck, even during such stress maneuvers as coughing and heel jouncing . These activities should not provoke any rise in detrusor pressure . Following satisfactory storage testing, the patient is asked to relax and void without straining, while pressure/flow EMG monitoring continues . Fluoroscopic screening of the bladder and outflow tract is accomplished throughout most of the voiding study, attention being given to the funneling of the bladder neck, opening of the proximal urethra in the female or prostatic urethra in the male, and the appearance of the external sphincter region . At sometime during the voiding study, the patient is asked to stop voiding momentarily, at which time external sphincter activity increases and voiding ceases briefly . Generally a high "kick" in subtracted bladder pressure occurs as the bladder isometrically contracts against a closed sphincter . Fluoroscopically "milkback" of urine from the level of the sphincter through the bladder neck should occur. However, it does not occur in cases of stress urinary incontinence with sphincter weakness in the female, following bladder neck or prostate resection in the male, and likewise in conditions of bladder neck dysfunction in the male when trapping of urine between external sphincter and bladder neck occurs giving a positive "Whiteside test ."6 Voiding completed, the residual urine is assessed fluoroscopically and checked by catheterization . A supine urethral pressure profile (by the constant infusion technique) is performed, while simultaneously monitoring rectal pressure and external sphincter EMG activity . Simultaneous measurement of external sphincter EMG is important to ascertain whether urethral closing pressure has been increased artifactually by voluntary or involuntary external sphincter contraction . In some complex female incontinence problems urethral pressure profilometry
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has been performed with postural variation and with the bladder full as proposed by Tanagho .' We have found these studies to be of limited value and exceedingly difficult to perform in any reproducible manner . Recently, in investigating children in whom the voiding study is important, we have used suprapubic filling and pressure-measuring catheters, positioned (together with the EMG electrodes), tinder general anesthesia twentyfour hours prior to study . This improves patient cooperation, and allows for repeat studies without the trauma of having to catheterize repeatedly a small child . The suprapubic catheters used have been 14-gauge Intramedicut IV lines, and no complications have arisen using this technique. Results Table I details the range of conditions and ultimate diagnosis of the 926 cases studied . The area of greatest yield was in the neurogenic bladder group where therapy was based entirely on urodynamic findings . Fifty-five cases referred for evaluation of micturition problems were found to have completely normal studies despite symptomatology. Rather than this being a negative finding it was found extremely helpful to the physician in terms of future management of that patient . Incomplete studies because of inability to void were infrequent and predominantly confined to the "female voiding dysfunction group," in which our diagnostic yield was the least. Comment We will make no attempt to cover comprehensively the urodynamic intricacies of the various lower urinary tract problems lending themselves to investigation, but have attempted to identify areas in which we have found video urodynamics to he of additional diagnostic value . Urinary incontinence Two hundred thirty (25 per cent) patients studied had problems of urinary incontinence, 96 per cent of whom were women . We believe that true primary stress incontinence does not require such elaborate preoperative workup . However, patients who have complex symptomatology, those who have had a previous failed repair, those with urinary incontinence together with a voiding dysfunction or residual urine, and those with evidence of a concomitant
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TABLE I.
Patient population studied
Urologic Condition Bladder outlet obstructive problems Urinary incontinence Neurogenic bladders Bladder hypersensitivity Female voiding problems Pretransplant bladder evaluation Pediatric workup Postprostatectomy problems Normal bladders TorAL
No. of Patients
Percentage of Total
114 230 241
12 25 26
96
10
90
10
14 24
2 3
62 55
7 6
926
neurologic lesion do justify video-urodynamic evaluation to ensure that one is dealing with a surgically correctable lesion . The data obtained might indicate the need for an alternative therapeutic approach or to counsel the patient preoperatively regarding the likelihood of success of surgery . We have found simple supine cystometry to be of little value in the identification of any but the most marked hyperreflexic bladders . One would imagine that our technique of using rapid fill would unmask most latent hyperreflexic patients . This however is not the case, and a significant proportion of our patients demonstrate detrusor activity only with the bladder full and in the erect position . The use of simultaneous fluoroscopic screening of the bladder outlet during provocative cystometry adds a new dimension to the differentiation of bladder neck and proximal urethral funneling due to anatomic outflow tract weakness, from that due to detrusor activity . If, during the storage phase of our study in the erect position, bladder neck opening is visualized but detrusor activity on the subtracted bladder pressure trace is seen to be absent, one must conclude bladder neck incompetence and hence true stress incontinence . Should detrusor pressure increase be evident at the time of bladder neck opening and urinary leakage, then detrusor or urge incontinence can be interpreted (Figs . 2, 3) . Cases of mixed stress urge incontinence also have been seen to occur but are more difficult to identify . Urethral pressure profilometry has been performed in all patients with urinary incontinence
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STRESS
URINARY INCONTINENCE
INCONTINENCE WITH UNSTABLE DETRUSOR
FIGURE 2 . Diagrams of still frame from video-urodynamic study . (A) Important features of "storage testing" in stress urinary incontinence arc bladder neck incompetence and leakage at time detrusor is stable . (B) In detrusor incontinence, bladder neck incompetence and leak associated with "active" detrusor on chart strip recording.
FiCURE 3, Detrusor or urge incontinence : still frame photograph of video screen during study of woman with urinary incontinence . Open bladder neck shown, and in detrusor pressure tracing, detrusor activity is evident .
undergoing urodynamic study ; however, the degree of correlation between simple supine (empty bladder) profilometry and our more objective video-urodynamic findings is poor . The addition of postural profilometry with varying degrees of bladder fullness, we believe, is valuable, but we have not extensively tried this .
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Fourteen of the 109 patients with stress urinary incontinence also had a voiding dysfunction, and we believe this group should be recognized prior to surgical correction, so that one may be forewarned of possible postoperative voiding difficulties . We believe that voiding problems in some cases are related to an out-
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FIGURE 4 . Video-urodynamic study of patient with spinal cord injury and "reflex bladder" after external sphincterotomy . Chart strip recording confirms detrusor hyperreflexia and dyssynergic sphincter activity . Man had persistently high residual urines after sphincterotomy and simultaneous video study reveals incomplete sphincterotomy .
flow tract distortional problem resulting from bladder base and urethral descent, and this problem might be resolved by a retropubic suspension procedure . Others, however, are due to inadequate detrusor function, and the addition of increased outflow resistance by surgical repair might lead to a worsened situation necessitating postoperative intermittent catheterization on a long-term basis . Neurogenic bladder
Two hundred forty-one (26 per cent) patients studied had neurogenic bladder dysfunction . In this group we believe that the identification of the functional status of the detrusor, the smooth muscle sphincter, the external striated muscle sphincter, together with the intactness of sensation and volitional control of the micturition reflex, is essential for the logical selection of a therapeutic approach . A urodynamic classification of neurogenic bladders,' divorced from the previously used descriptive or anatomic classifications, greatly facilitates management, and video urodynamics is an ideal method for identifying the various functional abnormalities . Pressure/flow/striated sphincter EMG studies allow for accurate identification of the functional
UROLOGY / JULY 1980 / VOLUME XVI . NUMBER I
status of the detrusor and external sphincter, and the addition of simultaneous cystourethrography enables one to visualize accurately the level of obstruction in the outflow tract (Fig . 4) . The adequacy of bladder neck and proximal urethral funneling cannot he assessed in any other way, and corroborative evidence of external sphincter dyssynergia is obtained by the actual visualization of a narrowed obstructive membranous urethra . In the more gross neurogenic bladders of the type seen commonly after spinal injury, adequate urodynamic data can be obtained frequently by the use of simple filling cystometry and striated muscle electromyography . In the more subtle lesions, however, we have found video urodynamics to be indispensible in determining the exact contribution of the detrusor or each of the sphincters to the problem . This is important particularly in the patient with relatively little somatic neurologic deficit but with voiding or continence disturbance . Bladder outlet obstruction
One hundred fourteen (12 per cent) patients studied were found to have bladder outlet obstructive problems of a non-neurogenic etiology . Whereas we would agree that the vast
III
Bladder neck obstruction shown on voidcystourethrogram . ing Simultaneous detrusor pressure tracing reveals obstructive maximum micturition pressure of 110 cm, of water and voiding peak flow rate of only 14 cc, lsec . FIGURE 5 .
majority of male outlet obstructive problems due to prostate or stricture disease can be managed without prior urodynamic evaluation, we identify certain factors which make their study rewarding in terms of diagnostic yield . Bladder neck obstruction due to a dyssynergic dysfunction rather than an endoscopically identifiable stenosis has been reported elsewhere .' Video urodynamics ideally identifies this problem by the simultaneous depiction of obstructive urodynamic recordings and visual appreciation of failure of bladder neck funneling (Fig. 5) . We have found this entity to he far more common than believed previously . Bladder outflow obstructive symptoms in patients who have neurological disease such as prior cerebrovascular accident or Parkinsonism should be studied to ensure that symptoms are due to organic obstruction and not neurogenic dysfunction . We have found prostatic symptomatology to he mimicked closely by the detrusor instability resultant from cerebrovascular catastrophies, and also by abnormalities of detrusor activity in Parkinson disease, or the effect of anti-Parkinsonian medications . Video urodynamics will identify the obstruction urodynamically and also will demonstrate elongation and narrowing of the prostatic urethra should it be obstructed pathologically .
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We believe that all women with outlet obstructive symptoms should be studied urodynamically since these conditions are invariably complex and generally due to detrusor malfunction with premature closure of the bladder neck rather than to endoscopically identifiable causes . Since endoscopic evidence of obstruction invariably is lacking in these patients, the video study offers the only objective way of evaluating outflow tract function . Although many cases of outlet obstruction are identifiable by the classic low-flow rate/high detrusor pressure relationship, the detrusor does not respond always to obstruction by increased activity . The advantage of video- urodynamic studies over routine pressure-flow micturition studies is that the level and degree of obstruction of the outflow tract can be identified even though classic alteration in pressure-flow indices may not be evident. Postprostatectomy problems
Sixty-two (7 per cent) patients studied were referred for evaluation of lower tract problems after previous prostatectomy . Twenty of these patients were referred because of urinary incontinence after transurethral resection or open surgery and identification of a sphincteric or detrusor cause was required prior to institution
UROLOGY / JULY 1980 / VOLUME XVI, NUMBER 1
of therapy, in the form of anticholinergic medication for the detrusor type, and alphaadrenergic pharmacotherapy or prosthetic sphincter surgery for the sphincter group . Most interesting were the remaining 40 patients who had persistent preoperative symptoms after their resections . The synchronous urodynamic/visual image study is an ideal method for identifying residual postoperative obstructive disease . In a number of cases, postresection cystoscopy had, it was said, ruled out any evidence of persistent obstructing adenoma . The persistence of a low flow/high pressure system together with tortuosity and narrowing of the prostatic urethra on the video was, however, found, and further judicious resection was successful . A number of patients had persistent symptoms of bladder instability without obstruction for which anticholinergic medication was advocated, and in whom spontaneous resolution of symptoms was anticipated . Sensory urgency and female frequency syndrome
Ninety-six patients comprising 10 per cent of our study population were women with "sensory urgency ." We by no means advocate this investigation routinely in this group of patients ; however, the patients studied were those with intractable symptoms and were referred from a wide surrounding area . These were cases which had been evaluated thoroughly by conventional urologic means, who had failed to respond to the usual therapeutic modalities, and referral requests were for exclusion of underlying neurologic causes and for therapeutic recommendations. Invariably, findings in this group were of bladder hypersensitivity on catheterization and filling, in the absence of detrusor hyperreflexia . Provocative testing by rapid fill, stress, catheter "tweaking," posture change, and heel jouncing failed to elicit any detrusor response . Hence, one could conclude that the symptoms of urgency were sensory in nature and not motor. No other significant urodynamic abnormalities were found in this group, most demonstrated reduced bladder capacities because of sensory disturbances, increased external sphincter activity on EMG during the holding pattern, and many exhibited high-normal urethral pressure profiles . Simultaneous fluoroscopy was rarely contributory ; however, a large number had narrowed distal urethras, the significance of which was uncertain . UROLOGY / JULY 1980 / VOLUME XVI, NUMBER I
Female voiding dysfunction
Women with symptomatic voiding difficulties of non-neurogenic origin accounted for 10 per cent of our patient population . Most of these women gave histories of chronic voiding problems with delay, intermittent and slow stream, straining to void, and some had episodes of retention . Urinary infections with high residual urines were frequent, and many were chronic infrequent voiders . It is notable that high pressure outlet obstruction was uncommon in these women, occurring in only 7 patients . Identification of the level of obstruction is possible during the simultaneous video study . As has been reported previously,iD the bladder neck was infrequently the cause of primary obstruction ; however, premature bladder neck closure due to a poorly sustained detrusor contraction was seen frequently . Distal urethral stenosis was diagnosed in a small number of patients, this diagnosis being based on the fluoroscopic appearance together with increase in urethral closing pressure on the distal limb of the profile in the absence of voiding sphincter dyssynergia on EMG study . Urethral distortion problems resulting from pelvic floor relaxation and bladder base descent during straining to void, we believe, were responsible for some cases . However, this group is exceedingly difficult to identify accurately, and it seems unlikely that distortion alone is responsible for the voiding dysfunction. This section of our patient population comprises our most confusing group . In many, accurate identification of causative problems was not possible . This was the group in whom pharmacologic manipulation using parenterally administered bethanechol and phentolamine was most used . There did seem to be little correlation between successful voiding during parenteral administration of these agents and subsequent response to the use of oral cholinergic or alpha-adrenergic blocking agents . Prerenal transplant evaluation
Sixteen patients with defunctionalized bladders due to prior supravesical urinary diversion, in whom renal transplantation was anticipated, were evaluated to determine acceptability of the bladder for transplant ureteroneocystostomy . In addition, other patients referred to our Center for refunctionalization after previous diversionary procedures were studied . We believe pressure/flow/EMG urodynamics alone are inadequate for the full evaluation of these 113
patients who need considerable care prior to refunctionalization . The addition of synchronous video cystourethrography allows for ideal appreciation of anatomic factors in unobstructed voiding and continence . Conclusions Cases requiring such elaborate investigation are relatively infrequent in everyday urologic practice ; however, they do occur on a frequency sufficient to establish a need for urodynamic referral centers capable of performing such sophisticated studies . More limited urodynamic study is still indicated, although care should be taken not to overinterpret the results . Absolute urodynamic values it appears are less important than patterns of results, and by more elaborate studies such as ours these patterns become more easily discernible and interpretable . Durham, North Carolina 27710 (DR. WEBSTER)
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References l . Tanagho EA, Miller ER, Meyer Fill, and Corbett RK : Observations on the dynamics of the bladder neck, Br . J . Urol . 38 : 72 (1966). 2 . Bates CP, Whiteside BM, and Turner-Warwick RT : Synchronous eine/pressure/flow/cystourethrography with special reference to stress and urge incontinence, ibid . 42: 714 (1970) . 3 . Bates CP, and Convey CE : Synchronous cine/pressure/flow cystography: a method of routine urodynamic investigation, ibid . 44 : 44 (1971) . 4 . Arnold EP, Brown AD, and Webster JR : Videocystography with synchronous detrusor pressure and flow recordings, Ann . R . Coll . Surg. Engl . (1974) . 5 . Whiteside CG : Videocystographic studies with simultaneous pressure and flow recordings, Br . Med . Bull . 28 : 214 (1972) . 6 . Turner-Warwick BT, Whiteside CG, and Worth PILL: A urodynamic view of prostatic obstruction, Br . J . Urol. 45: 44 (1973). 7 . Tanagho EA : Urodynamics of female urinary incontinence with emphasis on stress incontinence, J . Urol . 122: 200 (1979) . 8 . Raz S, and Bradley WE : Neuromuscular dysfunction of the lower urinary tract, in Campbell's Urology, 4th ed ., Philadelphia, W . B . Saunders, 1979, vol . 2, chap. 35, p. 1215 . 9. Webster CD, Lockhart JL, and Older R : The evaluation of bladder neck dysfunction, J . Uml . 123 : 196 (1980) . 10 . Webster JR : Combined video/pressure/flow cystourethrography in female patients with voiding disturbances, Urology 5: 209 (1975) .
UROLOGY
/ JULY 1980 /
VOLUME XVI,
NUMBER 1
ABSTRACT - Video urodynamics is a technique utilizing synchronously recorded urodynamic studies and cystourethrography for the evaluation of complex lower urinary tract problems . The technique and equipment used in approximately 900 consecutive studies is reported . The value of this method in the investigation of urinary incontinence, complex bladder outlet obstructive states, and neurogenic bladder in particular is presented .
During the past year 926 video-urodynamic studies have been performed for the investigation of a wide variety of lower urinary tract problems . Our technique is based on that originally described by Tanagho et al . in 1966,' which was subsequently put to wide clinical use by the Middlesex group in London, England . 2-5 Our studies have been modified from that described by Bates et al." to include sphincter electromyography and urethral pressure profilometry . Video-urodynamic studies comprise the performance of pre ssure/flow/electromyographic (EMG) studies of the lower urinary tract together with synchronous cystourethrography . We believe that the added sophistication of monitoring subtracted bladder pressure (detrusor pressure) is desirable, particularly for the identification of subtle detrusor instability states and for all micturition studies . The further addition of sphincter EMG monitoring in our hands has been found to be of value only in the evaluation of patients with neurogenic disease, and we now advocate routine performance of EMG studies only in those cases in which pathology of this nature is suspected . We believe that voiding studies are more widely indicated than currently practiced as we have found voiding dysfunction to go frequently hand in hand with bladder storage problems . Urethral pressure profilometry is performed extensively, and characteristic changes with different lower urinary tract problems have been reported . 106
However, we have found profilometry to be the least valuable and most inconsistently diagnostic aspect of our study . Cystourethrography for the identification of voiding dysfunction is used frequently, but is subject to misinterpretation, because changes in the appearance of the outflow tract can be interpreted meaningfully only if measurement of urine flow rate and detrusor pressure are obtained at the time the changes occurred . The combination of urodynamic and cystourethrographic techniques by the method to be later described overcomes these shortcomings, is indispensible for the evaluation of the more difficult urinary tract dysfunctions, and adds a new dimension to their investigation . Apparatus Figure 1 schematically depicts our equipment and its interconnections . There are three basic components, namely, urodynamic equipment, x-ray equipment, and video recording apparatus . Urodynamic equipment A Life-Tech Urolab 1154*, four-channel instrument capable of the simultaneous recording of rectal pressure, external sphincter EMG, subtracted bladder pressure, and total bladder pressure is used . The first rectal pressure "Life-Tech, Urulab, Houston, Texas .
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/ VOLUME X47,
NUMBER 1
channel is modular allowing for the switch-over to flow rate during the voiding study . The Urolab 1154 also allows measurement of urethral pressure profile and carbon dioxide cystometry, which is used infrequently . External sphincter EMG is, in addition, monitored by a Life-Tech 9000 EMG oscilloscope with audio . Urine flow rate during voiding is measured by the load cell principle which records urine flow rate and total volume voided . Fluoroscopy of voiding demands that micturition be performed in the erect position, and for this, a simple funnel shaped to fit the female perineum is utilized . 3 X-ray equipment
The study is performed on a standard Picker tilting x-ray table with fluoroscopic capability . The fluoroscopic image is transmitted via a Shintron special effects generator to a standard 19-inch television monitor . The Shintron special effects generator splits the television monitor screen in two, allowing display of the fluoroscopic image on the right side of the screen, the other half displaying the television recorded image from urodynamic chart strip recording . Video recording apparatus
A G.B.C . closed circuit low-light television camera is appropriately positioned to photograph continuously the urodynamic chart strip recording . This image is projected through the Shintron special effects generator to the left side of the television monitor. Hence, at any one time one can see on the video screen the graphic urodynamic study together with the simultaneous fluoroscopic appearance of the bladder and outlet . A permanent record of the study seen on the television monitor is obtained using a Sony video cassette recording device . Physician commentary during the study is recorded, greatly facilitating the understanding of the study during later playback . Fluoroscopic screening time is limited generally to a total of approximately one minute, and radiation exposure is estimated as equivalent to that of a single intravenous pyelogram series . Personnel
The urodynamic facility is staffed by a fulltime physician's assistant and a nurse, physician supervision and interpretation of all studies being accomplished. UROLOGY
/
JULY 1980
/
VOLUME XVI,
NUMBER I
Image intensifier
Life Tech Urolob ,-~
1154
UPP./CO Z Cystometer Pressure/Flow EMG Pressure Pressure
Life Tech 9000 EMS Oscilloscope and Audio
Shintron - Special Effects Generator 19"Television Monitor
FIGURE
1.
Schematic
drawing of equipment; note central role of special effects generator allowing
simultaneous projection of video appearance and urodynamic changes .
chart
strip
Sony -Videotape Recorder
Technique We attempt to evaluate completely bladder and sphincter function urodynamically and fluoroscopically during the phases of bladder filling, storage, and voiding . This study takes approximately one hour to perform, compromises an initial urine free flow rate prior to instrumentation, followed by continuous monitoring of rectal pressure, sphincter EMG, total bladder pressure, and subtracted bladder pressure during filling and storage phases . During voiding, urine flow rate is, in addition, monitored. Fluoroscopic video cystourethrography is performed intermittently during filling and storage phases, and generally the entire voiding 107
act is screened . At the completion of this study, urethral pressure profilometry is performed either singly or with varying degrees of bladder fullness and in varying postures . Rectal pressure is measured using a fluidfilled balloon constructed from a finger-stall fixed over a length of intravenous tubing . Care is taken to place it above the level of the sphincter to avoid artifact, and overdistention is avoided since it appears to stimulate rectal contractions . Intravesical pressure is measured using a perforated length of 1 .52 mm . O .D . (0 .86 mm . I.D .) polyethylene tubing, passed per urethra alongside the 12 F filling catheter . This tubing has been found to be of the correct consistency to allow for easy insertion and is kink-proof. Two electrodes of 39-gauge plastic-coated wire, the ends of which have been denuded of insulation for 0 .5 cm ., are introduced through a 27-gauge needle into an electrically active portion of the sphincter under oscilloscope control . We customarily place the electrodes in the anterolateral aspect of the external anal sphincter ; however, in suspected neurogenic dysfunction, they are placed directly into the external urethral sphincter by a transperineal route in the male and paraurethral insertion in the female . It is important to immobilize the wires completely by taping their entire length to the skin, for movement and bumping cause artifact . Voluntary control of sphincter activity and the bulbocavernosus reflex are tested prior to commencing the filling study . Filling cystometry using Cystografin solution (14%) is performed with patient in the supine position on the fluoroscopy table . A fast fill rate of 100 cc ./min . is used in adults, the rate being decreased in pediatric patients and neurogenic hyperreflexic bladders . We believe that a normal stable bladder will remain so regardless of the circumstances of filling, and that every attempt should he made to provoke the bladder to act in an unstable manner . Such provocation includes the use of rapid fill rates, stress, posture change, and the use of contrast medium at room temperature . Fluoroscopic screening during the filling study is brief to demonstrate bladder contour, presence or absence of reflux, and the competence of the outflow tract during stress . Filling is continued until the patient is uncomfortably full, when he is tipped into the upright position on the tilting fluoroscopy table and positioned rapidly to allow for oblique half-lateral fluoroscopic screen-
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ing of the bladder and outlet . The filling catheter is removed, the flow meter positioned, and the transducers leveled to the symphysis pubis and monitoring continued . On changing to the erect position there should he no increase in substracted bladder pressure ; however, a marked increase in intravesical pressure will be apparent due to the effect of the weight of abdominal viscera and abdominal muscle contraction on the bladder . Fluoroscopic screening of the bladder in this erect, half-lateral position should show competence of the bladder neck, even during such stress maneuvers as coughing and heel jouncing . These activities should not provoke any rise in detrusor pressure . Following satisfactory storage testing, the patient is asked to relax and void without straining, while pressure/flow EMG monitoring continues . Fluoroscopic screening of the bladder and outflow tract is accomplished throughout most of the voiding study, attention being given to the funneling of the bladder neck, opening of the proximal urethra in the female or prostatic urethra in the male, and the appearance of the external sphincter region . At sometime during the voiding study, the patient is asked to stop voiding momentarily, at which time external sphincter activity increases and voiding ceases briefly . Generally a high "kick" in subtracted bladder pressure occurs as the bladder isometrically contracts against a closed sphincter . Fluoroscopically "milkback" of urine from the level of the sphincter through the bladder neck should occur. However, it does not occur in cases of stress urinary incontinence with sphincter weakness in the female, following bladder neck or prostate resection in the male, and likewise in conditions of bladder neck dysfunction in the male when trapping of urine between external sphincter and bladder neck occurs giving a positive "Whiteside test ."6 Voiding completed, the residual urine is assessed fluoroscopically and checked by catheterization . A supine urethral pressure profile (by the constant infusion technique) is performed, while simultaneously monitoring rectal pressure and external sphincter EMG activity . Simultaneous measurement of external sphincter EMG is important to ascertain whether urethral closing pressure has been increased artifactually by voluntary or involuntary external sphincter contraction . In some complex female incontinence problems urethral pressure profilometry
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has been performed with postural variation and with the bladder full as proposed by Tanagho .' We have found these studies to be of limited value and exceedingly difficult to perform in any reproducible manner . Recently, in investigating children in whom the voiding study is important, we have used suprapubic filling and pressure-measuring catheters, positioned (together with the EMG electrodes), tinder general anesthesia twentyfour hours prior to study . This improves patient cooperation, and allows for repeat studies without the trauma of having to catheterize repeatedly a small child . The suprapubic catheters used have been 14-gauge Intramedicut IV lines, and no complications have arisen using this technique. Results Table I details the range of conditions and ultimate diagnosis of the 926 cases studied . The area of greatest yield was in the neurogenic bladder group where therapy was based entirely on urodynamic findings . Fifty-five cases referred for evaluation of micturition problems were found to have completely normal studies despite symptomatology. Rather than this being a negative finding it was found extremely helpful to the physician in terms of future management of that patient . Incomplete studies because of inability to void were infrequent and predominantly confined to the "female voiding dysfunction group," in which our diagnostic yield was the least. Comment We will make no attempt to cover comprehensively the urodynamic intricacies of the various lower urinary tract problems lending themselves to investigation, but have attempted to identify areas in which we have found video urodynamics to he of additional diagnostic value . Urinary incontinence Two hundred thirty (25 per cent) patients studied had problems of urinary incontinence, 96 per cent of whom were women . We believe that true primary stress incontinence does not require such elaborate preoperative workup . However, patients who have complex symptomatology, those who have had a previous failed repair, those with urinary incontinence together with a voiding dysfunction or residual urine, and those with evidence of a concomitant
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TABLE I.
Patient population studied
Urologic Condition Bladder outlet obstructive problems Urinary incontinence Neurogenic bladders Bladder hypersensitivity Female voiding problems Pretransplant bladder evaluation Pediatric workup Postprostatectomy problems Normal bladders TorAL
No. of Patients
Percentage of Total
114 230 241
12 25 26
96
10
90
10
14 24
2 3
62 55
7 6
926
neurologic lesion do justify video-urodynamic evaluation to ensure that one is dealing with a surgically correctable lesion . The data obtained might indicate the need for an alternative therapeutic approach or to counsel the patient preoperatively regarding the likelihood of success of surgery . We have found simple supine cystometry to be of little value in the identification of any but the most marked hyperreflexic bladders . One would imagine that our technique of using rapid fill would unmask most latent hyperreflexic patients . This however is not the case, and a significant proportion of our patients demonstrate detrusor activity only with the bladder full and in the erect position . The use of simultaneous fluoroscopic screening of the bladder outlet during provocative cystometry adds a new dimension to the differentiation of bladder neck and proximal urethral funneling due to anatomic outflow tract weakness, from that due to detrusor activity . If, during the storage phase of our study in the erect position, bladder neck opening is visualized but detrusor activity on the subtracted bladder pressure trace is seen to be absent, one must conclude bladder neck incompetence and hence true stress incontinence . Should detrusor pressure increase be evident at the time of bladder neck opening and urinary leakage, then detrusor or urge incontinence can be interpreted (Figs . 2, 3) . Cases of mixed stress urge incontinence also have been seen to occur but are more difficult to identify . Urethral pressure profilometry has been performed in all patients with urinary incontinence
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STRESS
URINARY INCONTINENCE
INCONTINENCE WITH UNSTABLE DETRUSOR
FIGURE 2 . Diagrams of still frame from video-urodynamic study . (A) Important features of "storage testing" in stress urinary incontinence arc bladder neck incompetence and leakage at time detrusor is stable . (B) In detrusor incontinence, bladder neck incompetence and leak associated with "active" detrusor on chart strip recording.
FiCURE 3, Detrusor or urge incontinence : still frame photograph of video screen during study of woman with urinary incontinence . Open bladder neck shown, and in detrusor pressure tracing, detrusor activity is evident .
undergoing urodynamic study ; however, the degree of correlation between simple supine (empty bladder) profilometry and our more objective video-urodynamic findings is poor . The addition of postural profilometry with varying degrees of bladder fullness, we believe, is valuable, but we have not extensively tried this .
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Fourteen of the 109 patients with stress urinary incontinence also had a voiding dysfunction, and we believe this group should be recognized prior to surgical correction, so that one may be forewarned of possible postoperative voiding difficulties . We believe that voiding problems in some cases are related to an out-
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FIGURE 4 . Video-urodynamic study of patient with spinal cord injury and "reflex bladder" after external sphincterotomy . Chart strip recording confirms detrusor hyperreflexia and dyssynergic sphincter activity . Man had persistently high residual urines after sphincterotomy and simultaneous video study reveals incomplete sphincterotomy .
flow tract distortional problem resulting from bladder base and urethral descent, and this problem might be resolved by a retropubic suspension procedure . Others, however, are due to inadequate detrusor function, and the addition of increased outflow resistance by surgical repair might lead to a worsened situation necessitating postoperative intermittent catheterization on a long-term basis . Neurogenic bladder
Two hundred forty-one (26 per cent) patients studied had neurogenic bladder dysfunction . In this group we believe that the identification of the functional status of the detrusor, the smooth muscle sphincter, the external striated muscle sphincter, together with the intactness of sensation and volitional control of the micturition reflex, is essential for the logical selection of a therapeutic approach . A urodynamic classification of neurogenic bladders,' divorced from the previously used descriptive or anatomic classifications, greatly facilitates management, and video urodynamics is an ideal method for identifying the various functional abnormalities . Pressure/flow/striated sphincter EMG studies allow for accurate identification of the functional
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status of the detrusor and external sphincter, and the addition of simultaneous cystourethrography enables one to visualize accurately the level of obstruction in the outflow tract (Fig . 4) . The adequacy of bladder neck and proximal urethral funneling cannot he assessed in any other way, and corroborative evidence of external sphincter dyssynergia is obtained by the actual visualization of a narrowed obstructive membranous urethra . In the more gross neurogenic bladders of the type seen commonly after spinal injury, adequate urodynamic data can be obtained frequently by the use of simple filling cystometry and striated muscle electromyography . In the more subtle lesions, however, we have found video urodynamics to be indispensible in determining the exact contribution of the detrusor or each of the sphincters to the problem . This is important particularly in the patient with relatively little somatic neurologic deficit but with voiding or continence disturbance . Bladder outlet obstruction
One hundred fourteen (12 per cent) patients studied were found to have bladder outlet obstructive problems of a non-neurogenic etiology . Whereas we would agree that the vast
III
Bladder neck obstruction shown on voidcystourethrogram . ing Simultaneous detrusor pressure tracing reveals obstructive maximum micturition pressure of 110 cm, of water and voiding peak flow rate of only 14 cc, lsec . FIGURE 5 .
majority of male outlet obstructive problems due to prostate or stricture disease can be managed without prior urodynamic evaluation, we identify certain factors which make their study rewarding in terms of diagnostic yield . Bladder neck obstruction due to a dyssynergic dysfunction rather than an endoscopically identifiable stenosis has been reported elsewhere .' Video urodynamics ideally identifies this problem by the simultaneous depiction of obstructive urodynamic recordings and visual appreciation of failure of bladder neck funneling (Fig. 5) . We have found this entity to he far more common than believed previously . Bladder outflow obstructive symptoms in patients who have neurological disease such as prior cerebrovascular accident or Parkinsonism should be studied to ensure that symptoms are due to organic obstruction and not neurogenic dysfunction . We have found prostatic symptomatology to he mimicked closely by the detrusor instability resultant from cerebrovascular catastrophies, and also by abnormalities of detrusor activity in Parkinson disease, or the effect of anti-Parkinsonian medications . Video urodynamics will identify the obstruction urodynamically and also will demonstrate elongation and narrowing of the prostatic urethra should it be obstructed pathologically .
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We believe that all women with outlet obstructive symptoms should be studied urodynamically since these conditions are invariably complex and generally due to detrusor malfunction with premature closure of the bladder neck rather than to endoscopically identifiable causes . Since endoscopic evidence of obstruction invariably is lacking in these patients, the video study offers the only objective way of evaluating outflow tract function . Although many cases of outlet obstruction are identifiable by the classic low-flow rate/high detrusor pressure relationship, the detrusor does not respond always to obstruction by increased activity . The advantage of video- urodynamic studies over routine pressure-flow micturition studies is that the level and degree of obstruction of the outflow tract can be identified even though classic alteration in pressure-flow indices may not be evident. Postprostatectomy problems
Sixty-two (7 per cent) patients studied were referred for evaluation of lower tract problems after previous prostatectomy . Twenty of these patients were referred because of urinary incontinence after transurethral resection or open surgery and identification of a sphincteric or detrusor cause was required prior to institution
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of therapy, in the form of anticholinergic medication for the detrusor type, and alphaadrenergic pharmacotherapy or prosthetic sphincter surgery for the sphincter group . Most interesting were the remaining 40 patients who had persistent preoperative symptoms after their resections . The synchronous urodynamic/visual image study is an ideal method for identifying residual postoperative obstructive disease . In a number of cases, postresection cystoscopy had, it was said, ruled out any evidence of persistent obstructing adenoma . The persistence of a low flow/high pressure system together with tortuosity and narrowing of the prostatic urethra on the video was, however, found, and further judicious resection was successful . A number of patients had persistent symptoms of bladder instability without obstruction for which anticholinergic medication was advocated, and in whom spontaneous resolution of symptoms was anticipated . Sensory urgency and female frequency syndrome
Ninety-six patients comprising 10 per cent of our study population were women with "sensory urgency ." We by no means advocate this investigation routinely in this group of patients ; however, the patients studied were those with intractable symptoms and were referred from a wide surrounding area . These were cases which had been evaluated thoroughly by conventional urologic means, who had failed to respond to the usual therapeutic modalities, and referral requests were for exclusion of underlying neurologic causes and for therapeutic recommendations. Invariably, findings in this group were of bladder hypersensitivity on catheterization and filling, in the absence of detrusor hyperreflexia . Provocative testing by rapid fill, stress, catheter "tweaking," posture change, and heel jouncing failed to elicit any detrusor response . Hence, one could conclude that the symptoms of urgency were sensory in nature and not motor. No other significant urodynamic abnormalities were found in this group, most demonstrated reduced bladder capacities because of sensory disturbances, increased external sphincter activity on EMG during the holding pattern, and many exhibited high-normal urethral pressure profiles . Simultaneous fluoroscopy was rarely contributory ; however, a large number had narrowed distal urethras, the significance of which was uncertain . UROLOGY / JULY 1980 / VOLUME XVI, NUMBER I
Female voiding dysfunction
Women with symptomatic voiding difficulties of non-neurogenic origin accounted for 10 per cent of our patient population . Most of these women gave histories of chronic voiding problems with delay, intermittent and slow stream, straining to void, and some had episodes of retention . Urinary infections with high residual urines were frequent, and many were chronic infrequent voiders . It is notable that high pressure outlet obstruction was uncommon in these women, occurring in only 7 patients . Identification of the level of obstruction is possible during the simultaneous video study . As has been reported previously,iD the bladder neck was infrequently the cause of primary obstruction ; however, premature bladder neck closure due to a poorly sustained detrusor contraction was seen frequently . Distal urethral stenosis was diagnosed in a small number of patients, this diagnosis being based on the fluoroscopic appearance together with increase in urethral closing pressure on the distal limb of the profile in the absence of voiding sphincter dyssynergia on EMG study . Urethral distortion problems resulting from pelvic floor relaxation and bladder base descent during straining to void, we believe, were responsible for some cases . However, this group is exceedingly difficult to identify accurately, and it seems unlikely that distortion alone is responsible for the voiding dysfunction. This section of our patient population comprises our most confusing group . In many, accurate identification of causative problems was not possible . This was the group in whom pharmacologic manipulation using parenterally administered bethanechol and phentolamine was most used . There did seem to be little correlation between successful voiding during parenteral administration of these agents and subsequent response to the use of oral cholinergic or alpha-adrenergic blocking agents . Prerenal transplant evaluation
Sixteen patients with defunctionalized bladders due to prior supravesical urinary diversion, in whom renal transplantation was anticipated, were evaluated to determine acceptability of the bladder for transplant ureteroneocystostomy . In addition, other patients referred to our Center for refunctionalization after previous diversionary procedures were studied . We believe pressure/flow/EMG urodynamics alone are inadequate for the full evaluation of these 113
patients who need considerable care prior to refunctionalization . The addition of synchronous video cystourethrography allows for ideal appreciation of anatomic factors in unobstructed voiding and continence . Conclusions Cases requiring such elaborate investigation are relatively infrequent in everyday urologic practice ; however, they do occur on a frequency sufficient to establish a need for urodynamic referral centers capable of performing such sophisticated studies . More limited urodynamic study is still indicated, although care should be taken not to overinterpret the results . Absolute urodynamic values it appears are less important than patterns of results, and by more elaborate studies such as ours these patterns become more easily discernible and interpretable . Durham, North Carolina 27710 (DR. WEBSTER)
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References l . Tanagho EA, Miller ER, Meyer Fill, and Corbett RK : Observations on the dynamics of the bladder neck, Br . J . Urol . 38 : 72 (1966). 2 . Bates CP, Whiteside BM, and Turner-Warwick RT : Synchronous eine/pressure/flow/cystourethrography with special reference to stress and urge incontinence, ibid . 42: 714 (1970) . 3 . Bates CP, and Convey CE : Synchronous cine/pressure/flow cystography: a method of routine urodynamic investigation, ibid . 44 : 44 (1971) . 4 . Arnold EP, Brown AD, and Webster JR : Videocystography with synchronous detrusor pressure and flow recordings, Ann . R . Coll . Surg. Engl . (1974) . 5 . Whiteside CG : Videocystographic studies with simultaneous pressure and flow recordings, Br . Med . Bull . 28 : 214 (1972) . 6 . Turner-Warwick BT, Whiteside CG, and Worth PILL: A urodynamic view of prostatic obstruction, Br . J . Urol. 45: 44 (1973). 7 . Tanagho EA : Urodynamics of female urinary incontinence with emphasis on stress incontinence, J . Urol . 122: 200 (1979) . 8 . Raz S, and Bradley WE : Neuromuscular dysfunction of the lower urinary tract, in Campbell's Urology, 4th ed ., Philadelphia, W . B . Saunders, 1979, vol . 2, chap. 35, p. 1215 . 9. Webster CD, Lockhart JL, and Older R : The evaluation of bladder neck dysfunction, J . Uml . 123 : 196 (1980) . 10 . Webster JR : Combined video/pressure/flow cystourethrography in female patients with voiding disturbances, Urology 5: 209 (1975) .
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