Detrusor contractility in post-menopausal women: Impact of ageing, complaint and urodynamic diagnosis.

INTRODUCTION: Detrusor contractility (DC) can have a considerable impact on the management oflower urinary tract symptoms (LUTS). However, it is currently impossible to predict, based on clinical data alone, which woman has an impaired DC. Our aim was to determine if DC, assessed by projected isovolumetric pressure-1 (PIP1) and VBN contractility parameter k, was associated with age, main complaint, and urodynamic diagnosis in a population of older women. METHODS: Pressure-flow studies of non-neurologic post menopausal women over 65 referred for investigation of LUTS were retrospectively analyzed. Associations between DC indices PIP1 and k, and age, main complaint and urodynamic diagnosis were assessed in univariate analysis. RESULTS: One hundred and ninety women were included (mean age 74.5 years). There was no significant association between detrusor contractility indices and age considered as a continuous or a categorical variable. Urge urinary incontinence was significantly associated with greater detrusor contractility regardless of age. Regarding urodynamic diagnoses, DC was greater when bladder outlet obstruction and detrusor overactivity were diagnoses vs. detrusor underactivity alone or associated with detrusor overactivity, regardless of age. CONCLUSION: PIP1 and k indices allow an easy evaluation of detrusor contractility. In that population of older, post menopausal women, no significant change in the value of the indices is observed with aging whatever the complaint or the urodynamic diagnosis. None of these indices has predominance. LEVEL OF EVIDENCE: 4.

Should we be revisiting LUT basic science and clinical measurement of LUT sensation to improve patient care? ICI-RS 2019.

AIMS: This article reviews current knowledge of the underpinning mechanisms of how the bladder senses fullness locally and also revisits clinical measurements of lower urinary tract sensation. The former represents cellular sensing during bladder filling whereas the latter describes the sensations leading to conscious perception of bladder fullness. METHODS: The topic was discussed in a "think tank" session at the 2019 International Consultation on Incontinence-Research Symposium in Bristol, UK; summarized in the present review. RESULTS: Recent advances in the basic science of bladder sensing relating to (a) the bladder wall-urothelial cells, sensory nerves, interstitial cells, and smooth muscle cells and (b) putative chemo/mechanosensors in the urethra-paraneurons or "brush cells" are discussed. Validated clinical measurement of lower urinary tract sensation is reviewed in the context of how this could be better harnessed for patient benefit. We discuss the potential of app/tablet/mobile technology based on triggers and distractors to override aberrant local sensing/higher sensation and how these technologies could be utilized in treatment. CONCLUSIONS: We conclude that a better understanding of bladder sensation is essential to inform clinical management of lower urinary tract symptoms.

What research is needed to validate new urodynamic methods? ICI-RS2017.

AIMS: In recent years urodynamic innovations, although well researched, have failed to follow a standardized development pathway specifically in terms of clinical trials undertaken to demonstrate efficacy. This was discussed at the International Consultation on Incontinence Research Society (ICI-RS) in Bristol, United Kingdom, 2017 with the aim of defining minimum standards for future urodynamic research. METHODS: The recent recommendations from the IDEAL (innovation, development, exploration, assessment, and long-term study) collaboration regarding surgical research were reviewed. Two examples of recent novel urodynamic technologies, the penile cuff test and air charged urodynamic catheters were used as case studies and the research programmes behind their development were critiqued. RESULTS: The rigorous and standardized model of surgical research proposed by the IDEAL collaboration was endorsed as an appropriate model for future urodynamic research. A methodical approach to research can fulfil a host of objectives including illustration of the clinical need, help with design and refinement of technique and proving efficacy for any new test or device. The penile cuff test is a novel urodynamic measurement technique that has been well researched and is now used in clinical practice. Further research is needed before air charged catheters can be recommended for widespread clinical use and the IDEAL framework provides a template for ongoing development. CONCLUSIONS: In the future, these recommendations should lead to a more standardized and uniform programme of urodynamic research and enable a thorough evaluation of new technologies prior to wider clinical uptake.

Are nomograms based on free uroflows helpful to evaluate urethral obstruction in men?

AIMS: It was demonstrated earlier that reduced maximum flow-rate (Qmax ) during intubated flow (IF) in women may be the consequence of a urethral reflex. Over-estimation of outflow obstruction is the consequence. Our hypothesis, that a similar phenomenon could occur in men, is tested using results of a free uroflow (FF) preceding an IF to eventually correct the Abrams-Griffiths (AG) number. METHODS: Retrospectively, analysis of 441 urodynamic studies of men suspected of bladder outflow obstruction (BOO) was performed. The Valentini-Besson-Nelson model links outflow obstruction (parameter pucp) and the detrusor contractility (parameter k) to Qmax and detrusor pressure at Qmax (pdet.Qmax ). AG and pucp are strongly correlated. Contractility is described by a graphical representation (a nomogram) which numerical fitting is an algebraic equation f(Qmax ,pdet.Qmax ). Nomograms based on IF allowed computing a calculated AG (corr-AG) on the basis of free flow. RESULTS: Included files (N = 362) had filling volume during FF > 90 mL; corr-AG was compared to AG. When Qmax.FF > 1.5*Qmax.IF (N = 114), 61 patients (53.5%) were found less obstructed with corr-AG, no one more obstructed. Increased BOO could be the result of a urethral reflex during IF and AG gave an overestimation. When Qmax.FF < 1.5*Qmax.IF (N = 248), only 39 patients (12.1%) were found less obstructed with corr-AG and 28 (11.3%) more obstructed. CONCLUSION: To obtain a reliable evaluation of BOO in men, it is suitable to perform a FF before IF. A corrected AG (corr-AG) obtained from IF analysis and nomograms based on FF may be helpful for evaluation of BOO in men.

Comparison of bladder voiding efficiency in women when calculated from a free flow versus an intubated flow.

OBJECTIVES: To assess the reproducibility of bladder voiding efficiency (BVE, Void%) between free flow (FF) and intubated flow (IF) and to correlate BVE measurements with urinary incontinence (UI) complaints and urodynamic (UDS) findings in women. METHODS: UDS recordings of women referred for LUTD evaluation to our UDS center were reviewed. Each file included FF at arrival, filling cystometry, and IF. Post-void residual volumes (PVR) were measured by catheterization after FF and IF. Women unable to void during the study or who expelled the catheter during IF, as well as studies with voided volume < 100 ml were excluded. Data was sub-analyzed according to 3 age categories, and UI complaints and UDS findings. RESULTS: Over the past 3 years, 237 UDS studies for FF and IF met all criteria. There was significant difference between voided volumes (232 vs. 335 ml) and PVR (24 vs. 71 ml) respectively (P < 0.0001). For the whole population, BVE IF (79.8 ± 28.6) was significantly lower than BVE FF (90.7 ± 15.9) (P < 0.0001). A significant decrease of BVE during IF was only noted for UI. BVE IF was significantly different in women in the peri-menopause and older groups. PVR IF increased with age and was significantly higher than PVR FF for women older than 45 years (P < 0.0001). CONCLUSIONS: BVE measurement in women has a role, but is most reliable from a FF. BVE is influenced by age and urinary incontinence complaints as well as UDS findings.

Can we define and characterize the aging lower urinary tract?-ICI-RS 2015.

The prevalence of lower urinary tract (LUT) symptoms increases with age but the etiology is unknown. This article aims to identify research directions that clarify the basis of this association. The initial question is whether biological age is the variable of interest or a time-dependent accumulation of factors that impact on LUT function at rates that differ between individuals. In particular, the accumulation of conditions or agents due to inflammatory states or tissue ischemia is important. Much of the above has been concerned with changes to bladder function and morphology. However, the outflow tract function is also affected, in particular changes to the function of external sphincter skeletal muscle and associated sacral motor nerve control. Nocturia is a cardinal symptom of LUT dysfunction and is more prevalent with aging. Urine production is determined by diurnal changes to the production of certain hormones as well as arterial blood pressure and such diurnal rhythms are blunted in subjects with nocturia, but the causal links remain to be elucidated. Changes to the central nervous control of LUT function with age are also increasingly recognized, whether in mid-brain/brainstem regions that directly affect LUT function or in higher centers that determine psycho-social and emotional factors impinging on the LUT. In particular, the linkage between increasing white matter hyperintensities and LUT dysfunction during aging is recognized but not understood. Overall, a more rational approach is being developed to link LUT dysfunction with factors that accumulate with age, however, the precise causal pathways remain to be characterized. Neurourol. Urodynam. 36:854-858, 2017. © 2017 Wiley Periodicals, Inc.

VBN-based nomograms provide critical voiding parameters which can be used for invasive or non-invasive flow interpretation of women at risk of obstruction over time.

AIMS: To design a simple office-based method to evaluate characteristic parameters from free uroflowmetries (FF) or pressure flow studies (PFs). This method can be applied by any physician to any recording, for instance in the follow-up of women at risk of developing outflow obstruction over time after surgical interventions. METHOD: Using pressure-flow studies (PFs), a reliable evaluation of urethral obstruction (U) and detrusor contractility (k) parameters could be obtained from the maximum flow rate and detrusor pressure at maximum flow rate. Nomograms for these parameters were derived from theoretical computations using the VBN model. Then, to allow an evaluation of the real urethral obstruction, a protocol was designed incorporating FF data in the follow-up of women suspected of urethral obstruction. RESULTS: Two nomograms were obtained: (1) A urethral obstruction nomogram allowing to define a Woman Obstruction Index (WOI = pdet.Qmax - 0.5*Qmax ) which has the same structure than the A-G number in men. (2) A detrusor contractility nomogram which was generalized to all initial bladder volumes. The curves were fitted by algebraic equations easily programmable on any handheld device. CONCLUSION: Using a mathematical model of micturition and data extracted from PFs, two nomograms on urethral obstruction and detrusor contractility were designed. This tool offers a rapid and practical method for the clinician to follow women at risk of obstruction over time. Its applications will be the purpose of further studies. Neurourol. Urodynam. 36:37-42, 2017. © 2015 Wiley Periodicals, Inc.

Detrusor after-contraction: a new insight.

AIMS: Detrusor after-contractions (DAC) are non-common in adults. Both definition (nothing in ICS reports) and significance (artefact, link with detrusor overactivity (DO) or bladder outlet obstruction (BOO)) remain discussed. Our purpose was to carry out an analysis of the urodynamic parameters during voidings with DAC and, using the VBN model, to simulate pathophysiological conditions able to explain both voiding phase and DAC. MATERIALS AND METHODS: From large urodynamic database of patients referred for evaluation of lower urinary tract dysfunction, DAC were observed in 60 patients (5.7%). Criteria for DAC were post-void residual <30mL and increase of detrusor pressure >10cmH(2)O. VBN model was used for analysis of both pressure and flow curves, and simulations of pathophysiological conditions. RESULTS: Onset of DAC (ODAC) occurred when Q=7.3±5.7mL/s and bladder volume=17.9±15.4mL. Urgency-frequency syndrome and urodynamic diagnosis of DO were the more frequent scenarios associated with DAC. ODAC was associated to an inversion of the slope of detrusor pressure curve without any perturbation in flow curve. Among tested pathophysiological hypothesis (great, abnormal, detrusor force, sphincter contraction), none allowed restoring all recorded curves (flow rate, voiding pressure and DAC). CONCLUSION: No urodynamic characteristic of the first part of voiding is an index of occurrence of DAC. ODAC is a significant phenomenon linked with the bladder collapse. DAC is not associated with BOO but more probably with DO and appears as the result of local conditions in an almost empty bladder (concentration of stresses around a transducer); thus DAC seems of weak clinical significance.

Detrusor after-contraction: a new insight

Detrusor after-contractions (DAC) are non-common in adults. Both definition (nothing in ICS reports) and significance (artefact, link with detrusor overactivity (DO) or bladder outlet obstruction (BOO)) remain discussed. Our purpose was to carry out an analysis of the urodynamic parameters during voidings with DAC and, using the VBN model, to simulate pathophysiological conditions able to explain both voiding phase and DAC.

Clinically relevant modeling of urodynamics function: the VBN model.

BACKGROUND: For the past two decades, a mathematical model of micturition was built step by step. Fundamental studies, presentations of the model and several applications to various male and female lower urinary tract dysfunctions have been published. We expect now that other teams will be interested in using it. In order to do so, a VBN pack (software in Linux and tutorial) is freely available. AIMS: The purpose of this review is to describe the model and to show its practical usefulness. MATERIALS AND METHODS: After a short description of the basis of the model and of how to use it, some published applications were summed up. The main application of the VBN model is to obtain a coherent modelling for a given patient from a set of several recordings (free uroflows and pressure-flow study) obtained either during the same session or in follow up. RESULTS: This experience gradually led us to study what information could be extracted from a free uroflow. In addition, the model is valuable to quickly compute the effect of some additional condition; thus, it can predict the effect of an experimental artefact (urethral catheter, penile cuff). CONCLUSION: Because the process of fitting model computations and real recordings is a powerful way to detect unexpected phenomena, the use of the VBN model provides a method to improve the knowledge of misunderstood dysfunctions of the lower urinary tract.

Non-invasive evaluation of bladder outlet obstruction in men suspected of benign prostatic hyperplasia: usefulness of the d index.

OBJECTIVE: To compare a new index of voiding dysfunction (D) based purely on free uroflow vs. Abrams-Griffiths (A-G) number obtained from intubated flow, for classification of bladder outlet obstruction in men. PATIENTS AND METHODS: Urodynamic tracings of 60 non-neurological patients (30 before transurethral resection of the prostate and of 30 men suspected of benign prostatic hyperplasia included in a medical therapy trial) were retrospectively analyzed. The Valentini-Besson-Nelson model was used to evaluate the value of the D index. A-G was obtained from intubated flows. Obstruction was defined as D > 32.5 cm H2O (translation of A-G criterion). RESULTS: D showed 82.05% sensitivity with 66.66% specificity; the positive predictive value was 82.05% and the negative predictive value 66.66% for the whole population, 83.3 vs. 80.9% sensitivity with 58.3 vs. 77.7% specificity for pre- transurethral resection of the prostate vs. medical therapy group. CONCLUSION: D index which can be obtained from a free uroflow appears as a valuable alternative to invasive urodynamic investigations when the diagnosis of bladder outlet obstruction needs to be more solidly established before a treatment decision or in men suspected of benign prostatic hyperplasia who elect for watchful waiting.

Decreased maximum flow rate during intubated flow is not only due to urethral catheter in situ.

INTRODUCTION AND HYPOTHESIS: We used the Valentini-Besson-Nelson (VBN) mathematical micturition model to analyze the potential obstructive effect of a 7-F transurethral catheter on the voiding process during intubated flow (IF) in women. Our hypothesis was that incomplete sphincter relaxation leads to residual sphincter pressure. METHODS: We reviewed a urodynamic database of women referred for evaluation of lower urinary tract dysfunction. Exclusion criteria were neurological disease or grade ≥2 prolapse. Eligible women underwent free uroflow (FF-1) before cystometry, an IF (7-F urethral catheter), and a second FF (FF-2) at the end of the session. Interpreted flows were restricted to voided volumes ≥100 ml and continuous flow patterns. Analysis of FF and IF was made using the VBN model. RESULTS: Among 472 women, 157 met the inclusion criteria. The effect of the urethral catheter was geometric only in 60 (38.2 %) patients. An additional effect, identified as incomplete sphincter relaxation, was observed in 97 (61.9 %) patients. Among this second group, the same residual sphincter excitation was found for 30 (30.97 %) patients during FF-2. CONCLUSION: When comparing IF with FF with the VBN model, the decrease in maximum flow rate (Q(max)) did not appear to result only from the geometric effect of the catheter but from incomplete sphincter relaxation during voiding, possibly because of patient's anxiety or a urethral reflex induced by the presence of the catheter. These findings emphasize the need to perform an FF before the IF to strengthen the reliability of conclusions of a urodynamic investigation.

Phasic or terminal detrusor overactivity in women: age, urodynamic findings and sphincter behavior relationships

OBJECTIVES: To search for relationships between phasic (P) and terminal (T) DO with age, urodynamic findings and sphincter behavior during involuntary detrusor contraction in woman. MATERIALS AND METHODS: Urodynamic studies (triple lumen catheter 7F, seated position) of 164 successive women referred for LUTS with diagnosis of DO were reviewed. Patients were stratified in 4 sub-groups: pre- (18-44y), peri- (45-54 y), post-menopause (55-74 y) and oldest old (≥ 75 y). The urethral sensor was positioned at the level of the maximum urethral closure pressure for sphincter behavior analysis. A variation of at least 5 cmH2O in pressure (detrusor or urethra) was chosen to assert DO or sphincter response. Sphincter response was classified as relaxation (re) before or during DO, or steady (st). RESULTS: Occurrence of P and TDO was similar: 77 P and 87 T. The PDO group was significantly younger (p = 0.0003). TDO was more frequent in patients with a history of neurological disease. The percentage of PDO remained almost constant in age groups, while that of TDO increased with age from 6.7 percent to 23.2 percent (p = 0.0013). Uninhibited contraction occurred at a smaller bladder volume in the P group: 149 ± 95 vs. 221 ± 113 mL (p < 0.0001). Steady sphincter predominated in the TDO subgroup: 45.9 percent vs. 32.1 percent and increased significantly in each DO sub-group of ³ 75y. CONCLUSION: Steady sphincter during both P and TDO, and occurrence of TDO appear as specific of aging. The last result could be related to structural changes in the detrusor muscle with aging.