Urethral Pressure Profile

Extrinsic compression of the bladder by uterine fibroids

Large cystocele

Uninhibited Bladder
Multiple bladder diverticulae

Neurogenic bladder with uninhibited detrusor contraction and associated leakage

Pictures Neurogenic Bladder

Fig. 49.12 Videocrystourethrography: Images.

Bladder trabeculation, diverticulae and right sided vesico-ureteric reflux

Multiple diverticulae, bladder trabeculation and an unprovoked contraction with leakage taken allowing an objective comparison of urethral function between patients and also before and after treatment. Although the concept of measuring the urethral pressure profile appears physiological there is considerable uncertainty regarding its use as a measure of urethral function and also as a prognostic tool.

Urethral pressure profilometry has been performed for at least 50 years, initially using balloon catheters and subsequently fluid perfusion. However, both these methods were unsatisfactory as they only enabled urethral pressure profile measurements to be made at rest and not under stress. Solid state microtransducer catheters are now employed. Two micro transducers are sited 6 cm apart on a 7 French silicone-coated solid catheter. They are gradually withdrawn at a constant rate along the length of the urethra, enabling the intraurethral and intravesical pressure to be recorded simultaneously. Many different parameters can be measured [49]; of particular interest are the maximum urethral closure pressure and functional urethral length (Figs 49.15 and 49.16). In addition, stress pressure

Cystometrogram Procedure
Fig. 49.13 Subtracted cystometrogram showing a picture of severe neurogenic detrusor overactivity in a patient with multiple sclerosis.

profiles can be performed if the patient coughs repeatedly during the procedure. This enables the pressure transmission ratio (the increment in urethral pressure, on stress, as a percentage of the simultaneously recorded increment in intravesical pressure) to be calculated. Urethral instability or relaxation can also be identified. Although urethral pressure profilometry is not useful in the diagnosis of uro-dynamic stress incontinence [50,51], it is helpful in women whose incontinence operations have failed and also in those with voiding difficulties.


Cystourethroscopy is normally carried out under general anaesthesia, but local anaesthesia is adequate if a flexible cystoscope is employed. Cystoscopy is particularly useful when there is a history of haematuria or recurrent urinary tract infections, or when no underlying cause can be found for sensory urgency or the symptoms of frequency, urgency or dysuria with normal urody-namic results. Cystoscopy may reveal abnormalities of the bladder epithelium, such as inflammation suggestive of infection, petechial haemorrhages or shallow ulcers due to interstitial cystitis. Papillomas or other tumours may be seen. Biopsies can be taken to confirm the underlying diagnosis, for example, mast cell infiltration in interstitial cystitis or a possible transitional cell carcinoma.

imaging of the lower urinary tract

Imaging of the lower urinary tract can be informative and, although videocystourethrography and cys-toscopy are still the most commonly employed techniques, other forms of radiology, ultrasound and, most recently, magnetic resonance imaging (MRI) are being employed increasingly frequently.

Micturition cystography has largely been replaced by videocystourethrography, as the morphological

Mri Intersticial Cystitis

Fig. 49.15 Urethral pressure profilometry - normal trace.

Urethral Pressure Profilometry

information it provides is similar. However, it can be used to diagnose an anatomical abnormality such as a fistula or a urethral diverticulum when lower urinary tract dysfunction is not suspected.

Intravenous urography has now largely been replaced by ultrasound of the upper urinary tract. However, it is important to perform an intravenous urogram in cases of haematuria, recurrent urinary tract infections, voiding difficulties or vesicoureteric reflux (Fig. 49.17). Additional pathology may be diagnosed, such as the presence of a ureteric fistula, a transitional cell carcinoma or calculi.

Ultrasound is now routinely used for assessing bladder volumes [52]. Abdominal, vaginal, rectal, perineal and introital ultrasound have all been employed and are

Ureteral Vagina Ultrasound Images

useful for estimating bladder capacity, urinary residual volume and assessing the upper urinary tracts. However, the role of ultrasound in the diagnosis of lower urinary tract dysfunction is still undergoing evaluation. Transvaginal ultrasound does allow clear visualization of the urethra and urethral diverticula. Bladder wall thickness of an empty bladder can be measured transvaginally giving a reproducible, sensitive method of screening for detrusor overactivity (a mean bladder wall thickness of >5 mm gave a predictive value of 94% in the diagnosis of detrusor overactivity) [53]. Measurement of bladder wall thickness has also been shown to have a role as an adjunctive test in those women whose lower urinary tract symptoms are not explained by conventional urodynamic investigations [54].

Rectal ultrasound [55] and perineal ultrasound [56] have been employed to examine the anatomy and mobility of the bladder neck and urethra, but it is important to appreciate that ultrasound cannot be used instead of urodynamic investigations which assesses the function rather than the morphology of the lower urinary tract.

Three-dimensional ultrasound is currently being employed mainly as a research tool. It can be used to estimate the volume of irregularly shaped organs such as the rhabdosphincter urethrae, which has been shown to be smaller in women with urodynamic stress incontinence than those with detrusor overactivity [57] and has also been shown to correlate with maximum urethral closure pressure [58]. Three-dimensional ultrasound has also been used to measure the levator ani hiatus which is significantly larger in women with prolapse than those with urodynamic stress incontinence or asymptomatic women [59].

Fig. 49.17 Intravenous urogram showing a right duplex ureter.

MRI is non-invasive and non-ionizing and allows tissues to be visualized in great detail. The urethra, bladder neck and pelvic floor have been examined [60] and fast MRI scan has been used to study prolapse [61]. Recently an erect MRI scan has been described but its applications have not yet been identified [62]. The use of this type of technology in clinical practice is contentious as it is expensive for limited information.


Electromyography can be employed to assess the integrity of the nerve supply to a muscle. The electrical impulses to a muscle fibre are measured following nervous stimulation. Two main types of electromyography are employed in the assessment of lower urinary tract dysfunction. Surface electrodes can be placed on the perineum, vagina or anal canal as an anal plug. The pudendal nerve is stimulated and potentials measured via the electrode. This is inaccurate as the muscular activity of the levator ani is not necessarily representative of that of the rhabdosphincter urethrae. Single fibre electromyography is more accurate as it assesses the nerve latency within individual muscle fibres of the rhabdosphincter. In this way denervation of motor units can be assessed. Research from Manchester has suggested that the occurrence of urodynamic stress incontinence postpartum is due to partial denervation of the pelvic floor musculature and rhabdosphincter urethrae and is characterized by increased motor latencies [63].

Electromyography is not useful in the routine clinical evaluation of patients with uncomplicated urinary incontinence. However, it may be useful in the assessment of women with neurological abnormalities or those with voiding difficulties and retention of urine. However, work from our own unit showed no difference in urethral sphincter electromyography parameters when women with urodynamically proven urodynamic stress incontinence (n = 33) and a continent control group (n = 35) were compared. Our findings suggested that dener-vation and reinnervation of the striated urethral sphincter may not be a major aetiological factor in the development of urodynamic stress incontinence [64].

Urethral electric conductance has not gained wide acceptance in the routine urodynamic assessment of women with urinary incontinence [65, 66]. A 7 French flexible probe with two ring electrodes 1 mm apart is withdrawn along the urethra. It measures the passage of urine along the urethra by registering the change in conductivity. This technique can be employed at the bladder neck to assess bladder neck opening, or in the distal urethra to detect urine loss. Different conductivity patterns are associated with different urodynamic diagnoses, and distal urethral electrical conductance has been recommended as a screening test for detrusor overactivity [67, 68]. It is now seldom used in clinical practice.

ambulatory urodynamics

All urodynamic tests are unphysiological and most are invasive. Various authors have suggested that long-term ambulatory monitoring may be more physiological as the assessment takes place over a prolonged period of time and during normal daily activities [69].

Ambulatory urodynamic studies are defined as a functional test of the lower urinary tract utilizing natural filling and reproducing the subjects everyday activities [2].

There are three main components to an ambulatory uro-dynamic system; the transducers, the recording unit and the analysing system (Fig. 49.18). The transducers are solid state and are mounted on 5 french and 7 french bladder and rectal catheters. It is our practice to use two bladder transducers in order to reduce artefact. The recording system should be portable in order to allow freedom of movement with a digital memory aiding compression and expansion of the traces which are obtained. An event marker is attached to the recording unit allowing the patient to mark episodes of urgency and also to document voids. In addition the recording unit is attached to an electronic (urilos) pad to document episodes of leakage during the study and should have the facility to attach to a flowmeter so as to record pressure flow voiding studies. The ambulatory protocol at Kings College Hospital consists of a 4-h period during which time the patient is asked to drink 200 ml of fluid every 30 min and also to keep a diary of events and symptoms (Fig. 49.19). On completion of the test the trace is then analysed with the patient using a personal computer and the urinary diary. Detrusor over-activity should only be diagnosed if there is a detrusor contraction noted in both bladder lines in the presence of symptoms (Fig. 49.20).


Fig. 49.18 Ambulatory urodynamic equipment demonstrating the (a) digital recording unit, and urilos pad and (b) microtip pressure transducer.

Fig. 49.18 Ambulatory urodynamic equipment demonstrating the (a) digital recording unit, and urilos pad and (b) microtip pressure transducer.

The clinical usefulness of ambulatory urodynamics is limited by the high prevalence of abnormal detrusor (38-69%) contractions in asymptomatic volunteers [70,71]. However the diagnosis of detrusor overactivity is highly dependent on interpretation of the results; in a prospective study of 26 asymptomatic women the incidence of detru-sor overactivity varied from 11.5% to 76.9% depending on the criteria used [72]. However, if the criteria for defining abnormal detrusor contractions are a simultaneous pressure rise on both bladder lines in addition to patient reported symptoms of urgency or urge incontinence the findings are normal in 90% of women which is similar to that reported in laboratory urodynamics.

Although ambulatory urodynamics is still considered to be mainly a research tool there is no doubt that it is often exceedingly helpful in cases where the clinical and conventional urodynamic diagnoses differ, or when no abnormality is found on laboratory urodynamics [73]. Ambulatory urodynamics have been shown to be more sensitive than laboratory urodynamics in the diagnosis of detrusor overactivity but less sensitive in the diagnosis of urodynamic stress incontinence [74] although their role in clinical practice remains controversial [75].

Getting Back Into Shape After The Pregnancy

Getting Back Into Shape After The Pregnancy

Once your pregnancy is over and done with, your baby is happily in your arms, and youre headed back home from the hospital, youll begin to realize that things have only just begun. Over the next few days, weeks, and months, youre going to increasingly notice that your entire life has changed in more ways than you could ever imagine.

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