Alexandros Derpapas

Novel biomarkers for overactive bladder

Biomarkers constitute any objectively measurable indicator of a biological process. The classic biomarker used in the diagnosis of overactive bladder (OAB) has been detrusor overactivity, which is assessed urodynamically. In the search for a reliable, noninvasive alternative to urodynamics, interest has focused on genetic, imaging, and urinary factors. Along with other cytokines detectable in urine, prostaglandin E2 and nerve growth factor are indicators of low-grade inflammation. Although they correlate with OAB symptom severity, they have not been shown to have independent prognostic benefit. Imaging biomarkers have been investigated since the earliest days of video urodynamics. Despite extensive research on the ultrasonographic estimation of bladder wall thickness, further standardization of the technique is required before conclusions can be reached regarding diagnostic accuracy. Genetic factors contribute approximately half of the total risk for urgency incontinence. Functional polymorphisms of the cytochrome P450 IID6 gene significantly alter the metabolism of some commonly used anticholinergic drugs, but no genetic loci that influence risk of OAB have been definitively identified. The first genome-wide association studies for OAB are in progress, and should identify new susceptibility genes. Although current putative biomarkers correlate with OAB severity, much future work is required to assess their prognostic value, and establish their role in clinical practice.

Are the measurements of water-filled and air-charged catheters the same in urodynamics?

Introduction and hypothesisThe aim of our study was to compare air-charged and water-filled catheters simultaneously in the measurement of the intravesical, abdominal and detrusor pressure during urodynamic investigations.MethodsConsecutive women with lower urinary tract symptoms, referred for urodynamics were prospectively studied. Readings of intravesical pressure (pves), abdominal pressure (pabd) and detrusor pressure (pdet), recorded by both the air-charged and water-filled catheters, were displayed simultaneously and compared at the end of filling, on standing, on sitting prior to voiding and at the maximum involuntary detrusor contraction. The signals (pressures) recorded by both types of catheter were compared using the Bland–Altman plot and paired samples t test.ResultsTwenty women with a mean age of 49 (range 36–72) were recruited. One patient with normal urodynamics was excluded in view of the poor quality trace. At each of the four comparison points, the air-charged catheters consistently produced higher mean pressures than the water-filled catheters. There were wide variations in the difference between the readings produced by the two types of catheter.ConclusionsPressures measured using air-charged catheters are not comparable with water-filled catheters and are therefore not interchangeable. Caution must be used when comparing urodynamic parameters using air-charged and water-filled catheters.

Changes in detrusor muscle oxygenation during detrusor overactivity contractions

OBJECTIVE To investigate changes in the oxygenated and deoxygenated haemoglobin (Hb) of the bladder wall during voluntary and involuntary detrusor contractions. STUDY DESIGN Women with lower urinary tract symptoms were recruited from a urodynamics clinic. Near infra-red spectroscopy, a non-invasive optical technique which monitors changes in tissue oxygenation, was used to measure oxygenated and deoxygenated haemoglobin simultaneously while the women underwent urodynamics. All data were compared using paired sample t-test. RESULTS Fifty-five women with a mean age of 52 years were enrolled into the study. In the 23 women with detrusor overactivity (15 with isolated detrusor overactivity and 8 with mixed urinary incontinence) there was a statistically significant rise in deoxygenated Hb during involuntary detrusor contractions at maximum detrusor pressure compared to the start of filling (p=0.02). There was no statistically significant change between Hb parameters measured at the start of the filling phase and those measured during voluntary detrusor contraction at pdetQmax (detrusor pressure at maximum flow rate). The mean detrusor pressure measured during voiding, however, was significantly higher than the maximum pressure during involuntary detrusor contractions (p=0.03). CONCLUSION There is a significant rise in the deoxygenated Hb in the detrusor muscle during detrusor overactivity, which is not seen during voiding even when the pdetQmax was higher than the peak detrusor pressure during involuntary contractions. These interesting changes in detrusor muscle oxygenation during involuntary detrusor contraction need to be explored further to assess if deoxygenation plays a role in the pathogenesis of detrusor overactivity.

Racial differences in female urethral morphology and levator hiatal dimensions: an ultrasound study.

To compare the urethral sphincter morphology and levator hiatal dimensions between white and black premenopausal nulliparous asymptomatic women using 3D/4D translabial ultrasonography.

Antimuscarinic effects on current perception threshold: A prospective placebo control study†‡§

To evaluate the effect of Tolterodine on urethral and bladder afferent nerves in women with detrusor overactivity (DO) in comparison to placebo, by studying the changes in the current perception threshold (CPT).

Reliability and validity of urinary nerve growth factor measurement in women with lower urinary tract symptoms

The validity and reliability of measurement of urinary NGF as a diagnostic biomarker in women with lower urinary tract dysfunction (LUTD) is uncertain. We aimed to evaluate both the diagnostic and discriminant validity, and the test–retest reliability of urinary NGF measurement in women with LUTD.

Prevalence of pubovisceral muscle avulsion in a general gynecology cohort: A computed tomography (CT) study

To calculate the prevalence of pubovisceral muscle (PM) avulsion in a cohort of women presenting at a university hospital for non‐urogynecological conditions.

Imaging in urogynaecology.

The assessment of patients with pelvic floor dysfunction necessitates a combination of clinical skills and adjunct investigations, including detailed imaging. This article reviews a variety of static and dynamic imaging modalities available in the field of urogynaecology, with an emphasis on their clinical implication in identifying the structural and functional causes of pelvic floor disorders. A number of different modalities have been used including X-rays, ultrasound and magnetic resonance imaging. Their place and value are discussed with comments on the validity of the various techniques.

A persistent bladder erosion with ureteric involvement following mesh augmented repair of cystocele

We present a case of a 57-year-old woman who sustained bladder erosion with extension to the left ureter after a mesh-augmented recurrent cystocele repair. The persistence of the eroding mesh eventually necessitated a partial cystectomy and distal left ureterectomy, using a Boari flap technique.

Real-time in vivo assessment of levator ani muscle deformation in women

OBJECTIVE To study the deformation of the levator ani muscle in vivo with the use of real-time ultrasound imaging of the pelvic floor. STUDY DESIGN Thirty-two women with symptoms of pelvic floor dysfunction underwent real-time in vivo assessment of the strain of the pelvic floor during Valsalva effort. All participants underwent clinical examination, urodynamics and 3D/4D translabial ultrasound scan of the pelvic floor. The deformation curves of the levator ani muscle were plotted and the difference in compliance according to the grade of urogenital prolapse was measured. One-way ANOVA and Spearmans correlation were used to test for significance of the relationship between variables (significance level P<0.05). Test-retest analysis of the ultrasound measurements of the levator hiatal dimensions was also conducted using intra-class correlation coefficient (ICC). RESULTS The deformation curve of the levator hiatus showed a non-linear relationship with gradually increased Valsalva force, which was quite pronounced in the pubourethralis subdivision of the levator ani muscle complex. Women with significant pelvic organ prolapse demonstrated a less compliant levator ani muscle close to its origin from the pubic bone than women with non-significant prolapse (median maximum strain 26% vs 32%, respectively, P=0.03). CONCLUSIONS Real-time in vivo assessment of levator ani muscle deformation in women is feasible and yields significant information.