Account for high flow rate-low detrusor pressure voids in female: Contribution of VBN model.

INTRODUCTION: Nomograms using the VBN model of women micturition allowed evaluating detrusor contractility (k) and urethral obstruction (U) from pressure-flow (PFs) recordings. While the model worked for most of the patients, an intriguing result, negative U value was observed for patients with high flow-low detrusor pressure (Qp voids). To explain that condition, our hypothesis was a weak urethral resistance to dilatation or increased expansibility (URD). METHODS: The area offered to the fluid at each point of the urethra (its dilatation) is a function of the time depending difference between inside and outside pressures. In the VBN model, this function is sigmoid-like, the same for all women. For Qp voids, Qrecorded was more higher than it would be with the recorded pressure (VBN analysis). So, modeling allowed computing abnormally increased urethral wall expansibility (URD) whose consequence would be an increased flow. RESULTS: Among 222 non-neurologic women referred for investigation of various lower urinary tract symptoms, 27 (mean age 66.3±11.4 y) had Qp void: Qmax=27±6mL/s; pdet.Qmax =7.5±4.7cm H2O. Mean URD value was .36±.67. Introduction of URD in a modeled analysis of urodynamic traces led to a good fitting between recorded and computed traces for the 27 Qp. CONCLUSION: Mathematical modeling of micturition allows proposing an explanation of the unexpected observations of Qp voids. They would be due to abnormal urethral wall elasticity. Despite major challenges measurement of this elasticity would be the next step. LEVEL OF EVIDENCE: 3.

Comparison of indices allowing an evaluation of detrusor contractility in women.

AIMS: To compare 3 detrusor contractility indices, projected isovolumetric pressure (PIP-BCI), PIP1, and k from the VBN mathematical model, for women referred for evaluation of various lower urinary tract symptoms (LUTS) in relationship to age, presenting complaint and urodynamic diagnosis. METHODS: Urodynamic tracings of non-neurologic women were analyzed. Three indices of detrusor contractility were measured from the pressure-flow study. Exclusion criteria were voided volume<100mL, stage>2 prolapse, interrupted flow, abdominal straining. Age sub-groups were pre-, peri- and post-menopause. Urodynamic diagnosis included incontinence findings and detrusor activity during voiding. RESULTS: Main complaint was incontinence (354 women); 95 women (Other) had non-incontinence LUTS. PIP-BCI, PIP1 and k decreased significantly with ageing in each sub-group. PIP-BCI was significantly different between MUI and Other (P=.0259) while PIP1 was significantly higher in UUI vs. Other (P=.0161) and k in UUI vs. SUI (P=.0107), MUI (P=.0010) and Other (P=.0224). Low value of PIP-BCI for bladder outlet obstruction vs. detrusor overactivity while PIP1 and k values were high and similar for these two diagnoses and a high value of PIP-BCI for detrusor overactivity with impaired contractility close to the value for bladder outlet obstruction while PIP1 and k were low. CONCLUSION: Evaluation of detrusor contractility in women is easily obtained using indices PIP-BCI and PIP1 or using the VBN nomogram giving indice-parameter k. PIP1 and parameter k produced comparable and consistent results with the urodynamic diagnosis while PIP-BCI leads to inconsistencies. LEVEL OF EVIDENCE: 4.

Is bladder voiding efficiency useful to evaluate voiding function in women older than 65 years?

AIMS: The aims of the study were to evaluate the reproducibility of bladder voiding efficiency (BVE) between free flow (FF) and intubated flow(IF) in old women, and to search for a relationship of this index with complaint and urodynamic diagnosis. METHODS: Urodynamic tracings of non-neurologic women referred for investigation of various lower urinary tract symptoms (LUTS) were analyzed. Urodynamic study included one FF followed by one cystometry and IF. Post void residual volume (PVR) was measured using a Bladder-scan. Exclusion criteria were voided volume<100ml and prolapse of grade>2. RESULTS: One hundred and ninety women met the study criteria. The mean age was 74±6 years [65-96years]. The main complaint was urinary incontinence: stress (26), urge (53) and mixed (56). Forty-four women had various complaints without incontinence. Overall BVE IF (77.6±25.8) was significantly lower than BVE FF (90.4±15.3) (P<.0001). Age sub-groups stratification led similar results. BVE IF was significantly lower than BVE FF in women with incontinence whatever the cause. Urodynamic diagnosis was posed according to the ICS/IUGA recommendations and 2 sub-groups defined according with involvement of detrusor. BVE IF was significantly lower than BVE FF for detrusor dysfunction, except for detrusor overactivity. CONCLUSION: In this large cohort of old non-neurologic women studied urodynamically for a variety of LUTS, BVE is higher when evaluated from a FF whatever age and for complaint of urinary incontinence. In addition, a low BVE value from an IF may suggest a detrusor dysfunction. LEVEL OF EVIDENCE: 4.

Do urodynamics provide a better understanding of voiding disorders in women over 80?

AIMS: Population ageing has as consequence an increasing number of women older than 80 years with lower urinary tract symptoms (LUTS). Despite old age, urodynamic study is often performed to diagnose the cause of LUTS. Our purpose is to discuss the contribution of urodynamics to manage that population. METHODS: Urodynamic studies of 169 consecutive women older than 80 years, respectively 124 non-neurological (non-N) and 45 neurological (N), were retrospectively analysed. RESULTS: Number of co-morbidities was lower in non-N (2.5 vs. 3.1) with predominance of cardiovascular and endocrinology while musculo-skeletal, cognitive and previous pelvic surgery predominated in N. Among main complaint, incomplete retention or dysuria was more frequent in N while incontinence and frequency were predominant in non-N. More frequent urodynamic diagnosis (UD) was "normal" i.e. non contributive (25.0%) and intrinsic sphincter deficiency (ISD=21.7%) in non-N, detrusor overactivity (DO=42.2%) and detrusor underactivity (DU=38.8%) in N. In non-N, there were 94 treatment proposals based on the complaint when UD was "normal" and on UD for DO, DU and ISD. In N, treatment proposals were mainly prompted voiding or self-catheterization based on DU diagnosis. CONCLUSION: Usefulness of urodynamics to manage LUT dysfunction in women older than 80 y is greatly dependent on their neurological status. In non-neurological women this is non debatable but proposed treatment needs to take into account existing co-morbidities. In neurological women the main usefulness is to unmask DU and to propose the best management in order to avoid complete retention. LEVEL OF EVIDENCE: 4.

Usefulness of an algebraic fitting of nomograms allowing evaluation detrusor contractility in women.

AIMS: Nomograms based on Valentini-Besson-Nelson (VBN) model implying only 3 measurements (filling bladder volume, maximum flow-rate [Qmax] and detrusor pressure at Qmax) were recently developed to evaluate detrusor contractility (k) and urethral obstruction (U) in women. As their algebraic fitting leads to fast evaluations (Excel® software), our aims were applications to populations of non-neurologic women without and with bladder outlet obstruction (BOO). METHODS: The software was applied to measurements obtained during pressure flow studies. Hidden hypothesis of nomograms were no significant contribution of abdominal pressure between onset of flow and Qmax and standard nervous excitations until Qmax. Studied populations were 202 women without symptom suggestive of obstruction and 125 women with proven anatomical urethral obstruction who underwent urodynamic study. RESULTS: For non-obstructed women, a good agreement was found between the values of k and U obtained using nomograms or a complete VBN analysis of the recorded curves. Whatever the obstructive status, there was a good correlation between the value of k and U. Evolution with ageing was similar with higher values of k and U in the BOO group. Curves k(age) and U(age) gave coefficients allowing an age adjustment. The high k value in the detrusor overactive (DO) group was consistent with a similar effect to that of BOO on the detrusor. CONCLUSION: Evaluation of detrusor contractility (k) and urethral obstruction (U) can be obtained from the point of Qmax during pressure-flow study. Evolution with ageing is similar with (higher values) or without BOO. DO also induces an increased detrusor contractility. LEVEL OF EVIDENCE: 4.