STUDIES ON THE DYNAMICS OF MICTURITION: OBSERVATIONS ON HEALTHY MEN

Choice of cystometric technique impacts detrusor contractile dynamics in wistar rats

The objective of the current animal study was to investigate factors contributing to the different phases of the cystometrogram (CMG) in order to address disparities in research data reported in the current literature. Three experiments in 20 female Wistar rats were designed to investigate (1) the effects of anesthesia on the contractile pattern of the bladder during micturition; (2) the impact of the physical characteristics of the CMG technique upon the accuracy of intra-vesical pressure recordings; and (3) identification of physiological and methodological factors associated with the emptying and rebound phases during CMG. Variables tested included awake versus urethane-anesthetized conditions, use of a single catheter for both filling and intra-vesical pressure (Pves) recording versus a separate two catheter approach, and comparisons between ureter, bladder dome, and urethral catheter placements. Both awake and anesthetized conditions contributed to variations in the shape and magnitude of the CMG pressure curves. In addition, catheter size, acute incision of the bladder dome for catheter placement, use of the same catheter for filling and Pves recordings, as well as the placement and positioning of the tubing, all contributed to alterations of the physiological properties and characteristic of the various CMG phases, including the frequent occurrence of an artificial rebound during the third phase of micturition. The present results demonstrate how different experimental conditions lead not only to variability in Pves curves, but consistency of the measurements as well, which needs to be accounted for when interpreting CMG outcome data.

Detrusor after contractions in men with lower urinary tract symptoms: Myth or reality?

Objectives

To study after contractions in men with lower urinary tract symptoms (LUTS) related to bladder outlet obstruction (BOO), in the absence of neuropathy, and to verify whether it is associated with the severity of symptoms or certain filling and voiding variables.

Patients and methods

Of 380 patients with LUTS and who were assessed using urodynamic studies, we retrospectively analysed those who had after contractions (ACs). Bladder overactivity was diagnosed as any increase in the detrusor pressure of <2-s duration during the filling phase, and an AC was diagnosed as any increase in the detrusor pressure of ⩾2 s after the end of the voiding phase and complete cessation of flow. The presence of ACs was then assessed in relation to different components of the International Prostate Symptom Score (IPSS), using a two-tailed Levene’s test, and to filling and voiding cystometry variables, using Mann–Whitney-Wilcoxon Rank test.

Results

In all, 373 of the 380 patients were included (seven had invalid voiding cystometry); ACs were detected in 51 (13.9%). There was no statistical significance for associations between AC and any of the variables assessed, including individual questions of the IPSS, detrusor overactivity, cystometric capacity, compliance, maximum urinary flow rate (Q_max), detrusor pressure at Q_max or the maximum detrusor voiding pressure.

Conclusion

ACs detected on voiding cystometry of men with LUTS attributed to BOO do not seem to be related to symptoms, or filling and voiding variables.

Paruresis (psychogenic inhibition of micturition): cognitive behavioral formulation and treatment

Paruresis is a condition characterized by difficulty or inability to urinate in situations where others are present, or may soon be present. Despite knowledge that paruresis can significantly impact on occupational functioning, social functioning, and quality of life, there exists a paucity of research into effective treatments. Although cognitive conceptualizations have been advanced for other anxiety disorders, there has not been a comprehensive cognitive behavioral model of paruresis. This article presents a revised cognitive and behavioral conceptualization of paruresis, drawing on empirical evidence from other anxiety disorders. Using this conceptualization, a cognitive-behavioral intervention strategy is outlined, with clear targets for cognitive and behavioral strategies.

Acute anal stretch inhibits NMDA-dependent pelvic-urethra reflex potentiation via spinal GABAergic inhibition in anesthetized rats

The impact of acute anal stretch on the pelvic-urethra reflex potentiation was examined in urethane-anesthetized rats by recording the external urethra sphincter electromyogram activity evoked by the pelvic afferent stimulation. Test stimulation (1 stimulation/30 s) evoked a baseline reflex activity with a single action potential that was abolished by gallamine (5 mg/kg iv). On the other hand, the repetitive stimulation (1 stimulation/1 s) induced spinal reflex potentiation (SRP) that was attenuated by intrathecal 6-cyano-7-nitroquinoxaline-2,4-dione (a glutamatergic α-amino-3-hydroxy-5-methyl-4-isoxazoleproprionat receptor antagonist, 100 μM, 10 μl) and d-2-amino-5-phosphonovalerate [a glutamatergic N-methyl-d-aspartate (NMDA) antagonist, 100 μM, 10 μl]. Acute anal stretch using a mosquito clamp with a distance of 4 mm exhibited no effect, whereas distances of 8 mm attenuated and 12 mm abolished the repetitive stimulation-induced SRP. Intrathecal NMDA (100 μM, 10 μl) reversed the abolition on SRP caused by anal stretch. On the other hand, pretreated bicuculline [γ-aminobutyric acid (GABA) A receptor antagonist, 100 μM, 10 μl] but not hydroxysaclofen (GABAB receptor antagonist) counteracted the abolition on the repetitive stimulation-induced SRP caused by the anal stretch. All of the results suggested that anal stretch may be used as an adjunct to assist voiding dysfunction in patients with overactive urethra sphincter and that GABAergic neurotransmission is important in the neural mechanisms underlying external urethra sphincter activity inhibited by anal stretch.

Detrusor after-contractions in children with normal urinary tracts

OBJECTIVE

To assess the clinical significance of after-contractions (A-Cs) in children with normal urinary tracts.

PATIENTS AND METHODS

Urodynamic records obtained in 315 children with urinary infection or enuresis were reviewed retrospectively; 184 were selected for analysis of A-Cs. All patients had normal urinary tracts and none showed signs of an overt neuropathy. The urodynamic method comprised standard measurements of pressures and flowmetry (42 had video-urodynamic studies).

RESULTS

After-contractions occurred in 151 of the 184 patients; the incidence tended to decrease with age. The mean amplitude of the A-Cs was 77.9 cmH2O; in 36% of the records it was higher than the voiding contraction. Residual urine was found in 12 of 151 records with A-Cs, but in only one patient was such residual urine confirmed in control voids. The patterns were assessed in 131 patients: in 36% they resembled stop-test responses, in 31% they were preceded by brief peaks of pressure or had jagged limbs, and in 33% they were grossly irregular. In 137 records the content of the bladder was estimated at the start of A-Cs; in 51% the bladder was empty or had evacuated >95% of its content, in 39% 95-80% and in 10% <80%. In only 7% of the patients had the A-Cs started after the voiding contraction had completely subsided. There was no difference in the incidence of A-Cs in girls with enuresis (84%) and girls with a history of urinary infections (85%). Detrusor instability was detected in 81% of the children with A-Cs and in 70% of those without; there was no correlation between the amplitudes of uninhibited detrusor contractions and of A-Cs. Characteristic images of external sphincter activity were found in only three of 14 video-urodynamic recordings with A-Cs.

CONCLUSION

After-contractions are common in children with normal urinary tracts but they tend to disappear with age. In clinical urodynamics they are of limited practical use because their appearance is unpredictable and there are artefacts related to recording the final phase of micturition. The relationship with detrusor instability may be explained as a coincidence of two common but unrelated findings, and A-Cs are unrelated to urinary infection. External sphincter activity is not the only cause of A-Cs and when it occurs it does not alter the course of voiding, as it does in neuropathic dysfunctions. As their clinical significance is uncertain, treatment of A-Cs is not advocated.

Uroflowmetry

Uroflowmetry is a widely used noninvasive screening modality for patients who present with symptoms of lower urinary dysfunction. However, it should be recognized that uroflowmetry represents the compound effect of bladder and urethral function because it may easily be misinterpreted. In elderly men with "prostatism", uroflowmetry is often sufficient to indicate treatment, while the value in women is less prominent. In pediatrics, more sophisticated urodynamic testing is crucial.

Nitric oxide synthase in dog urethra: a histochemical and pharmacological analysis

1. To examine the presence of nitric oxide synthase (NOS) activity in female dog urethra, pharmacological experiments were performed using electrical field stimulation (EFS), guanethidine, atropine, NG-nitro-L-arginine methyl ester and L-arginine, NOS immunohistochemistry using specific anti-NOS antibody, and reduced nicotinamide adenine dinucleotide phosphate (NADPH) diaphorase staining were also performed. 2. EFS caused frequency-dependent contractions in all urethral preparations, but in the presence of guanethidine and atropine, EFS caused significant relaxation in the proximal urethra and was without effect on the distal urethra. 3. In the presence of guanethidine, atropine, and NG-nitro-L-arginine methyl ester, small contractions to EFS were re-established in the proximal urethra, but not in the distal urethra. NG-nitro-D-arginine methyl ester had no such effect. 4. In the presence of guanethidine, atropine, and NG-nitro-L-arginine methyl ester, the addition of L-arginine, restored the EFS-elicited relaxant responses previously seen with guanethidine and atropine alone in the proximal urethra (at 30 Hz; 12.89 +/- 5.27% to -2.44 +/- 4.43%, mean +/- s.e., P < 0.05). D-Arginine had no such effect. 5. In the distal urethra, the addition of NG-nitro-L-arginine methyl ester and then L-arginine had no effect on responses to EFS in preparations treated with guanethidine and atropine. 6. Sodium nitroprusside caused relaxation in both the proximal and distal urethra. The relaxant responses per cm2 cross sectional area in the proximal and distal urethra were 1.23 +/- 0.29, and 2.02 +/- 0.54 g cm-2 cross sectional area (mean +/- s.e.), respectively: there was no significant difference between them. 7. Both NOS and NADPH diaphorase-positive neurones were present in dog urethra, the densities of both being higher in the proximal urethra than in the distal urethra. 8. These results show that female dog urethra possesses NOS nerves and that endogenous NO may play a role in relaxation in the proximal but not the distal urethra.

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

OBJECTIVE

To obtain data on conventional artificial filling cystometry and ambulatory monitoring in healthy asymptomatic control populations.

SUBJECTS AND METHODS

Seventeen healthy volunteers were assessed by means of artificial filling cystometry (CMG), filling at rates of 50 ml/min (CMG 50) and 100 ml/min (CMG 100), and ambulatory monitoring (AM).

RESULTS

Significant differences were found between AM and CMG with respect to: the pressure rise on filling (P < 0.02), voided volumes (P < 0.01) and maximum detrusor pressure on micturition (P < 0.01). Detrusor instability was found in 38% of volunteers on AM, in 17% on CMG 50, but in none on CMG 100.

CONCLUSION

A range of baseline urodynamic values has been established which could provide the basis for future studies of ambulatory monitoring.

Nitric oxide synthase in pig lower urinary tract: immunohistochemistry, NADPH diaphorase histochemistry and functional effects

1. The distribution and colocalization of nitric oxide synthase (NOS)-like immunoreactivity and NADPH diaphorase activity in the pig lower urinary tract were investigated by immunohistochemical and histochemical staining techniques. Functional in vitro studies were performed to correlate the presence of NOS-immunoreactivity/NADPH diaphorase staining with smooth muscle responses involving the L-arginine/nitric oxide (NO) pathway. 2. NOS-immunoreactivity and NADPH diaphorase activity were expressed in nerve trunks and fine nerve fibres in and/or around muscular bundles in the detrusor, trigone and urethra. Thin nerve fibres that dispersed within the muscle bundles were mainly found in the urethral/trigonal area, whereas such fibres were less common in the detrusor. 3. Almost all neuronal structures that were NOS-immunolabeled were also stained for NADPH diaphorase. In contrast, the urothelium, which was intensively stained by the NADPH diaphorase technique, remained unstained by immunohistochemistry. 4. Electrical field stimulation of pig isolated trigonal and urethral preparations induced relaxations, which were inhibited by tetrodotoxin (1 microM) and NG-nitro-L-arginine (L-NOARG, 10 microM). 5. L-Arginine (1 mM), but not D-arginine, inhibited (25-30%) electrically evoked detrusor contractions. This inhibition was reversed by L-NOARG (0.1 mM). L-Arginine did not inhibit detrusor contractions in the presence of scopolamine (1 microM) and had no direct smooth muscle effects per se. 6. Acetylcholine (1 nM-10 microM) caused concentration-dependent relaxations of noradrenaline-induced contractions in pig vesical arteries. Removal of the endothelium practically abolished the acetylcholine-induced relaxation. Pretreatment with L-NOARG (0.1 mM and 0.3 mM) caused a rightward shift of the concentration-response curves to acetylcholine, but the maximal relaxation obtained was significantly reduced (to 65 +/- 12%; n = 6; P < 0.05) only at 0.3 mM L-NOARG. 7. In vessel segments contracted with K+ (60 mM), acetylcholine induced concentration-dependent relaxations. When the vessels were incubated with 0.3 mM L-NOARG and then contracted with K+ (60 mM) all relaxant responses to acetylcholine were abolished. 8. The presence of NO synthesizing enzyme in nerve fibres and the pharmacological evidence for NO-mediated relaxation of the trigone and urethra suggest that NO or a NO-related substance may have a role in inhibitory neurotransmission in these regions. In the detrusor, the presence of NO-synthesizing enzyme in nerves can be demonstrated, but its functional importance is unclear. NO, as well as other endothelium-derived factors seem to be involved in the endothelium-dependent acetylcholine-induced relaxation of pig vesical arteries.

Longitudinal observations on normal and abnormal voiding in men over the age of 50 years

A cohort of 200 men over the age of 50 years was selected at random. Initially 112 men participated. After 5 years 61 were participating, and 2 years later 34 men still had no voiding problems, while 19 had had treatment for prostatism. A history was obtained and all 112 had symptom analysis and uroflow examination. The uroflow variables Qmax, Qave, Qmax-time, Q "corrected", volume and the ratio Qmax/Qmax-time were recorded together with the symptom score and subjective evaluation. After 5 and 7 years all primary data were reviewed in the 61 and 34 men respectively, while a full history was obtained in the rest. The 3 sets of data were evaluated separately as 3 cross-sectional investigations and as paired data sets by means of non-parametrical statistical analysis. Comparing the 3 sets of data longitudinally, significant differences were found in Qmax, Qave, Qcor and Acc. A correlation analysis showed that Qmax, Qave, Q "corrected" and volume decreases significantly with advancing age in asymptomatic men, while no correlation with age was found in the 19 treated men. On the basis of the 93 men, untreated for 7 years, nomograms of Qmax, Volume and Acc were constructed using 2.5, 25, 50, 75 and 97.5% percentiles in 5-year groups. Likewise, a nomogram on symptom score was constructed on the basis of the 82 men, asymptomatic and untreated for 7 years. In conclusion, uroflow in subjectively normal men over the age of 50 years shows increasing abnormality with advancing age. At the same time elderly men tolerate a considerable amount of symptoms of infravesical obstruction. The severity of symptoms increased with advancing age, but differently in persons likely and not likely to need operation.

Myelinated primary afferents of the sacral spinal cord responding to slow filling and distension of the cat urinary bladder

1. A total of sixty-five sacral afferent neurones with myelinated fibres supplying the urinary bladder was recorded from the sacral roots S2 in anaesthetized cats. All afferent units were identified with electrical stimulation of the pelvic nerve. The discharge properties were quantitatively evaluated using slow filling at rates of 1-2 ml min-1 and isotonic distension to preset pressure levels. Eight afferents were studied prior to and after acute sacral de-efferentation of the urinary bladder. 2. All afferent units were silent when the bladder was empty and responded in a graded manner to an increase of intravesical pressure. During slow filling the level of afferent activity correlated closely with the level of the intravesical pressure. All afferents behaved like slowly adapting mechanoreceptors with both a dynamic and static component of their discharge. With the exception of two units the intraluminal pressure threshold was below 25 mmHg. Thus virtually all myelinated afferents respond in the pressure range that is reached during a non-painful micturition cycle. 3. The stimulus-response functions of the afferents were similar regardless of whether intravesical pressure was increased by slow filling or by distension. However, during slow filling stimulation response functions often exhibited steeper slopes between 5 and 25 mmHg indicating that relatively small changes of intravesical pressure result in large changes of afferent activity. Nevertheless, all units displayed monotonically increasing stimulus response functions throughout the innocuous and noxious pressure level. 4. The stimulus-response functions of the afferent neurones did not change after acute de-efferentation of the urinary bladder, although the rapid phasic fluctuations of afferent activity that are produced by small contractions of the urinary bladder under normal conditions largely disappeared. This means that contractions and distension activate the afferent endings by a common mechanism. 5. It is concluded that the myelinated sacral afferents of the urinary bladder form a homogeneous population which encodes all information necessary for the normal regulation of this organ. Furthermore, this set of afferents mediates all sensations which may reach consciousness within a normal micturition cycle.

Paruresis: overview and implications for treatment

Paruresis or psychogenic urinary retention is a functional disorder of micturition characterized by psychosomatic symptomatology that includes an inability to void urine in public facilities. Through largely non-experimental studies and case reports, clinical investigators have identified characteristics, behaviors, and etiological factors associated with the disorder. Although few reports about paruresis appear in the literature, a review is presented to describe the disorder and compare treatments used. As adjuncts to a multifaceted approach to treatment, the 1948 Kegel exercises and the use of beta-adrenergic blocking drugs are specific methods for alleviating the maladaptive symptomatology.

Functional characteristics of lumbar visceral afferent fibres from the urinary bladder and the urethra in the cat

Neural activity of lumbar visceral afferents supplying the urinary bladder and urethra was analyzed systematically in the cat. The afferent fibres were isolated either from the white rami L3 and L4 in a preparation with closed peritoneal cavity, or from the lumbar splanchnic nerves in a preparation with open peritoneal cavity and investigated for various functional parameters. Seventy five single units and 9 multiunit bundles were analyzed. About 50% of the afferent units had some ongoing activity (0.2 to 1 imp/s). Two thirds of the afferent axons were thin myelinated (conduction velocity 3-15 m/s), the rest were presumably unmyelinated (conduction velocity below 2 m/s). The receptive fields of the afferent units consisted - with one exception - of single mechanosensitive sites on the surface of the bladder and urethra. Most receptive fields were situated on the dorsal side of the bladder. Afferents with receptive fields on or in the bladder wall responded in a graded manner to passive distension and isovolumetric contraction at intravesical pressures ranging from about 10 to 70 mm Hg. The thresholds for exciting the afferent units ranged from less than 10 mm Hg to about 30 mm Hg intravesical pressure, most of them being less than 20 mm Hg. Generally, the discharge rate of the afferent units gave a reliable representation of the intravesical pressure to the lumbar spinal cord. Urethral units exhibited either no responses to the graded distensions and contractions of the urinary bladder, or responded with low discharge rates at higher intravesical pressures.(ABSTRACT TRUNCATED AT 250 WORDS)

Uroflowmetry in asymptomatic elderly males

Uroflowmetry is important in the evaluation of prostatism. We have investigated 93 men, selected at random from the National Register, who had no subjective voiding problems but who fell within the appropriate age range. The sample was representative of the male metropolitan population. Uroflowmetry was carried out and the data are presented graphically in nomograms where the Q max/volume, Q average/volume and Q max time/volume relations are given. Flow variables were evaluated to delineate possible correlations to age. It was found that the median Q max decreased from 18.5 ml/s at the age of 50 years to 6.5 ml/s at 80 years. Only one-third of the group had a Q max exceeding 15 ml/s. The median voided volume was 208 ml. Half of the subjects voided less than 200 ml and one-third less than 150 ml.

Urodynamic findings in elderly males without prostatic complaints

Previous evaluations of urodynamic testing in patients with prostatism have been impeded because of a lack of age-matched controls. In this study, 13 asymptomatic male volunteers, ages fifty-two to seventy years, underwent urodynamic testing which included uroflowmetry, water cystometry, and pressure flow study. Comparison of these data to those obtained with patients with prostatism revealed several important differences including maximum flow rate and minimum urethral resistance.

Measurement of urinary flow rate

The various methods for measuring urinary flow rate from the first attempt by Rehfisch in 1897 to current techniques are described. The benefits or deficiencies of each method are considered, and it is concluded that while some of the more technically sophisticated pieces of equipment are necessary for the accurate determination of flow rates in the research laboratory, they are not necessarily the most appropriate for use in the consulting office or clinic.

Study of micturition parameters in healthy young adults using a uroflowmetric method

Using the 21 F 01 DISA Mictiograph, the instant urine flow curves of fifty normal males and thirty-three females (aged from 18 to 35 years) were analysed. A total of 363 micturitions was obtained (146 in the female group, 217 in the male group). Ten parameters were derived from each of the urine flow curves. These parameters were: the voided volume, the micturition time, the average-flow rate, the flow at 2 s, the maximum flow rate, the percentage of difference between the maximum flow rate and the average-flow rate, the duration until the maximum flow rate, the initial slope of the curve, the slope at the time from micturition initiation of voiding to maximum flow, and the difference between the two slopes. This study demonstrated that the urine flowmeter allowed, even at very low voided volume, a complete interpretation of micturition flow curves, a finding which might be useful in paediatric patients. It was also shown that the flow parameters were significantly more favourable in females than in males, and consequently that better hydrodynamics conditions for micturition exist in women compared to men.

High flow infravesical obstruction in men: symptomatology, urodynamics and the results of surgery

High flow infravesical obstruction in male patients with severe prostatism is defined by a maximum flow rate of more than 15 ml. per second and a vesical pressure exceeding 100 cm. water at maximum flow rate. During a 9-month period urodynamic screening of 225 patients referred to our hospital with prostatism revealed high flow infravesical obstruction in 16 (7 per cent). Transurethral surgery of the prostate or bladder neck was performed in 11 of the patients, with good results observed in symptomatology as well as in maximum flow rate. A urodynamic screening program is suggested to establish the diagnosis so that these patients can benefit from surgical treatment.

Urorectodynamic evaluation of healthy volunteers

Twelve female and 8 male healthy volunteers underwent urorectodynamic evaluation. Mean bladder capacity was 594 ml. and mean maximal vesical pressure 12.5 cm. water (H2O). Maximal bladder pressure correlated significantly with maximal mural tension (r = 0.96) but did not correlate well with bladder capacity (r = 0.20). Mean bladder volume at first desire to void was 32 per cent of mean bladder capacity. The bladder volume at the first desire did not correlate significantly with the capacity. Mean bladder pressure at 100 ml. volume was 2.9 +/- 0.4 cm. H2O (X +/- SEM). After bethanechol injection, the bladder pressure at 100 ml. volume increased by 8.8 +/- 1.2 cm. H2O (X +/- SEM) at twenty minutes. In only 1 subject did bladder pressure rise higher than 15 cm. H2O (5 per cent). Rectal pressure increased from 1.4 +/- 0.3 to 14.1 +/- 2 cm. H2O (X +/- SEM) at sixteen minutes. Electromyogram (EMG) of the external and sphincter did not follow regular pattern with vesical filling or attempt of voiding. The data obtained in these normal subjects may serve as a basis for comparison in the interpretation of data obtained in patients.

Normal peak urinary flow rates obtained from small voided volumes can provide a reliable assessment of bladder function

The urinary flow rates of 3 normal men were measured for a wide range of bladder volumes. Linear transformation of voiding curve data indicated that the relationship between urinary flow and voided volume could be described as parabolic, hyperbolic or logarithmic. These functional relationships were found to hold irrespective of age and volume, although deviations from the calculated voiding curves occurred at higher volumes. If only voiding data for volumes less than 150 ml. were considered, then, in addition to the aforementioned mathematical relationships, the dependence of flow on volume could be described validly by a straight line function, the slope of which represents an individual's best possible voiding potential.

Prostatism. III. Detrusor hyperreflexia and residual urine. Clinical and urodynamic aspects and the influence of surgery on the prostate

Detrusor reflex function and residual urine were assessed in 104 consecutive patients referred to hospital with prostatism. 53% of the patients had detrusor hyperreflexia, whereas a decompensated bladder was found in only 10% of the patients. A longer duration of symptoms was found among the patients with decompensated bladder, suggesting two different clinical courses of bladder outlet obstruction. Detrusor hyperreflexia did not bear any statistically significant correlation to urodynamic parameters of intravesical obstruction, but in 26 of the patients with detrusor hyperreflexia undergoing surgery on the prostate, 69% (95% confidence limits, 48-86%) gained normal detrusor reflex function 6 months after surgery. Residual urine volume was statistically significantly correlated to urodynamic parameters reflecting the function of the detrusor muscle, but not to the maximum flow rate.

Bladder recovery in patients with traumatic cervical cord injury evaluated by voiding synchronous cystosphincterometry with uroflowmetry

Voiding synchronous cystosphincterometry with uroflowmetry was used in 16 patients with traumatic cervical cord injury to evaluate bladder recovery. This method was shown to be reliable since the statistical analysis of the voiding responses showed the same values with repeated tests. A total of 14 patients with such injuries recovered from shock in 6 weeks and 10 acquired mature bladder contraction with a synergic external sphincteric urethra approximately 13 weeks after spinal cord injury. Bladders in patients with cervical cord injury usually recover from a state of inactive detrusor to that of a mature contraction by way of immature small and/or sustained contractions. Pressure measurements revealed 7.1 plus or minus 3.7 cm. water in the empty bladder and 74 plus or minus 20.5 cm. water (43 plus or minus 13.3 seconds in duration) in the recovered bladder contraction. Resting pressure in the external sphincteric urethra was 70 plus or minus 25.3 cm. water. The dyssynergic sphincter coexists with immature sustained bladder contraction and it usually improves to the synergic state, according to the degree of maturity of bladder contraction. The bladder and external urethral sphincter recover independently and a synergic response develops even in cases of complete lesions. Thus, synergy can be accomplished by regulatory mechanisms at the sacral cord level. Surgical intervention should be postponed if the maturity of bladder contraction is not yet established. More precise objective information in the dyssynergic bladder caused by cervical cord injury can be obtained when voiding synchronous cystosphincterometry with uroflowmetry is used.

Urodynamic evaluation: periurethral striated EMG versus perianal striated EMG

Fifty consecutive spinal injury patients who underwent simultaneous EMG of the peri-urethral and perianal striated muscles along with cystometrogram on a multiple channel recorder are analysed. Bladder filling, voiding and also influence of spasticity on the EMG activity of both perianal and periurethral striated muscles were compared. Periurethral striated EMG along with CMG has a better diagnostic value (95 per cent) as compared to perianal EMG-CMG which was diagnostic in 72 per cent patients.

Prostatism. II. The correlation between cysto-urethroscopic, cystometric and urodynamic findings

The cysto-urethroscopic findings in 93 out of 107 consecutive patients referred for symptoms of bladder outlet obstruction were assessed and graded with special reference to bladder wall trabeculation, patency of the bladder neck, prostatic occlusion of the urethra, the estimated prostatic weight and the bladder neck-verumontanum distance. The cysto-urethroscopic findings of trabeculation and prostatic enlargement were not statistically significantly correlated to the cystometric demonstration of detrusor hyperreflexia. However, urodynamic parameters of infravesical obstruction judged by the opening pressure, maximum flow rate and the calculated urethral resistance were statistically significantly correlated to the cysto-urethroscopic findings of prostatic occlusion of the urethra, increased bladder neck-verumontanum distance and an increased prostatic weight estimated at cystoscopy. It is concluded that cysto-urethroscopy gives good information of as well the site as the hydrodynamic severity of organic infravesical obstruction.

The flow rate nomogram: I. Development

In normal individuals the flow rate depends on the initial bladder volume in a non-linear fashion. A flow rate nomogram taking this relationship into account was developed as an aid in the interpretation of urinary flow rate data. With this approach excellent differentiation of normal from obstructed individuals was achieved. In addition, the variability in a single individual's flow rate over time was estimated to be relatively small and, thus, uroflowmetry may be used to identify changes in outflow resistance after medical or surgical therapy.

Management of neurogenic bladder in infancy and childhood

Sixty-two patients, age twelve years and under, were treated for incontinence due to neurogenic bladder secondary to spina bifida (58) or trauma (4) with a follow-up period of three to thirty-two months (mean, ten months). In early life, patients were managed with the Credé maneuver (18 patients). Older children were managed with intermittent clean catheterization (44 patients) with or without pharmacologic agents. Continence was achieved with intermittent clean catheterization in 77 per cent, thus enabling these children to be more acceptable to their peers and in many cases attend schools from which they had previously been excluded because of urinary incontinence. With the Credé maneuver, renal deterioration was noted in 11 per cent on follow-up IVP, and in 2 per cent of the patients on intermittent clean catheterization. Recurrent asymptomatic bacteriuria occurred in 33 per cent of those with the Credé maneuver and in 55 per cent of the patients using intermittent clean catheterization. The use of antibiotic bladder irrigations reduced this incidence to 5 per cent. All patients with renal deterioration except one responded to intermittent clean catheterization; this patient was treated with cutaneous vesicostomy. Urodynamic assessment was performed in 15 patients, and this diagnostic tool assisted in the therapeutic management of these children.

Prostatism. I. The correlation between symptoms, cystometric and urodynamic findings

One hundred and seven consecutive patients referred with symptoms of bladder outlet obstruction were studied using cystometry and combined pressure-flow-electromyographic investigation. The symptoms of infravesical obstruction were not statistically significantly correlated to the hydrodynamic documentation of increased bladder outlet resistance as judged by maximum flow rate and the calculated urethral resistance. Irritative symptoms such as frequency, nocturia, urgency and urgeincontinence were statistically significantly correlated to the presence of detrusor hyperreflexia. The functional disorder bladder neck dyssynergia was encounterd in 5% of the patients (95% confidence limits 1-10%). This diagnosis cannot be made by conventional urological investigations. It is concluded that objective demonstration of infravesical obstruction is mandatory in the selection of patients with symptoms of lower urinary tract dysfunction for surgery on the prostate or the bladder neck.

Detrusor-sphincter dyssynergia and dyssynergic responses: recognition and rationale for early modified transurethral sphincterotomy in complete spinal cord injury lesions

Some characteristics are described for detrusor-sphincter dyssynergia and the dyssynergic response in spinal injury patients with complete lesions. The urodynamic evaluation and clinical problems are analyzed in 53 patients to identify the importance of early recognition of sphincter dyssynergia. Cystomanometric and urethral profile pressures vary from 30 to 150 cm. water. Although high voiding pressure, particularly associated with autonomic dysreflexia, may be indicative of sphincter dyssynergia it is not diagnostic. Relevant characteristics of patients with detrusor-sphincter dyssynergia are 1) rhythmic detrusor contractions on cystomanometry with associated marked increase in electromyographic activity on attempted voiding. These characteristics enable early recognition of dyssynergia and afford expediency in its management. The modified approach to external sphincterotomy as practiced by the author provides optimal surgical approach for urological rehabilitation of dyssynergic patients. Thus, the rationale for characterization of dyssynergia and its management by modified sphincterotomy can help to terminate long-term intermittent catheterization, remove indwelling catheter, prevent renal damage and ameliorate autonomic dysreflexia.

Voiding pattern abnormalities in children

Forty-two children with voiding pattern abnormalities (wetting, incontinence, inappropriate voiding) were evaluated by urodynamic techniques. All patients were urologically evaluated and carefully appraised of the mechanics of the urodynamic testing procedure. All patients demonstrated good cooperation in an anxiety-free atmosphere. Twenty-three abnormal bladder types were identified and characterized. Specific pharmacologic and urologic modalities were applied to achieve improved or normal micturition.

Techniques and results of urodynamic evaluation of children

Simultaneous recording of intravesical pressure, urine flow rate and anal sphincter electromyography was undertaken in 25 children with a variety of urological problems. Urethral pressure profile measurement was obtained in 3 of these patients and was used as an adjunct to cystometry alone in 5 others. The diagnostic patterns that emerged were useful in selecting specific pharmacologic and surgical therapeutic measures.

The non-neurogenic neurogenic bladder

The records of 21 children with neuropathic bladder disease are reviewed. The natural history in these cases has been consistent with that of an acquired disorder and the results of urodynamic testing have supported Hinman's contention that the disease is basically a functional one, caused by a discoordination between detrusor contraction and sphincter relaxation. Bladder retraining and specific medication have yielded far better results than were obtained previously by surgical measures alone.

Combined cystometric, sphincter electromyographic and uroflowmetric studies before and after transurethral resection of the prostate

Detrusor and urethral function was studied in 10 patients before and 3 months after transurethral resection of the prostate by means of flowmetry, and simultaneous gas cystometry and integrated sphincter electromyography. THE PATIENTas cystometry and integrated sphincter electromyography. The patient had no clinical signs of neurological disease. Six had neurogenic exaggeration of the detrusor reflex in the preoperative studies. In 3 patients changes in the detrusor reflex were found postoperatively. Postural changes in detrusor reflex excitability were encountered preoperatively and postoperatively. The preoperative finding of detrusor hyperreflexia in the majority of the patients is ascribed to lesions in the detrusor reflex organization at 2 anatomical sites: 1) a subclinical lesion of the cerebral circuits of the detrusor reflex control owing to arteriosclerosis and 2) an increase of sensory detrusor-reflex triggering stimuli from the morphologically changed prostatic urethra. The study calls for diagnostic techniques for delineation of minimal cerebrospinal impairment and objective assessment of the sensory innervation of the urethra.

Disposable peak urinary flowmeter estimates lower urinary tract obstruction

Peak urinary flow rate represents the highest flow rate achieved during a single urination and, as such, represents the patient's best effort at micturition. Peak flow rate, correlated with patient age and volume voided, effectively estimates lower urinary tract obstruction. The 63 normal and 368 abnormal male subjects urinated in privacy into a plastic sterile disposable device (the peakometer), which measured peak flow rate and volume voided. These data plus age, ultimate diagnosis and interval since last urination comprised our data base. Percentage distribution of diagnosis in this population was prostatic obstruction 47.3 per cent, stricture 19.3 per cent, normal 14.6 per cent, prostatitis 8.4 per cent, neurogenic bladder 2 per cent and miscellaneous 8.4 per cent. The average peak flow rate for normal male subjects reaches 27.6 ml. per second, which differs significantly from that for patients with prostatic obstruction--9.4 ml. per second, stricture--10.5 ml. per second, prostatitis--16.3 ml. per second and neurogenic bladder--13.9 ml. per second. The peak flow rate decreased progressively as the age of the subjects increased. We measured average decreases of 10 ml. per second peak flow for every 30 years after age 10. Peak flow rate increases as volume voided increases. Requirements of our measuring device combined with urodynamic responses caused us to select 100 ml. voided as the minimum acceptable volume. With volumes more than this any given individual may deviate plus or minus 10 per cent from the true mean peak flow depending upon volume voided. For practical purposes peak flow, age and volume must be considered to categorize voiding by peak flow rate. With these variables 2 graphs that compare peak flow, age and volume may be used to estimate voiding function for a given male patient. Comparison of peak flow rates, volume voided and voiding interval before and after surgical correction of obstruction documented significant increase in volume voided or in interval between voiding. Peak urinary flow rate measurement by this device predicted normality or abnormality with 90 to 95 per cent accuracy. Therefore, this represents a valid screening test but it does not in itself provide the diagnosis of abnormal urination.