Over Active Bladder Index (OABI): A New Objective Tool Based on Uroflow Parameters for Diagnosis of Overactive Bladder in Children

AIMS

The aim of this study is to propose an objective uroflow based index for diagnosing over active bladder (OAB).

MATERIALS AND METHODS

Thirty patients with OAB and 30 controls were used in the pilot study. Three uroflow parameters: Uroflow index (UI = Qave/Qmax), voided volume ratio (VVR = voided volume/expected bladder capacity) and time to Q max (TQmax) were studied. Linear regression was performed for the three parameters with controls/OAB patients. Further 28 patients & 32 controls were recruited in a second validation study.

RESULTS

Mean (s.d) UI was 0.7 (0.1) in control while 0.4 (0.1) in OAB (p = 0.001). Mean (s.d) VVR was 0.7 (0.1) in control while 0.5 (0.1) in OAB (p = 0.01). Mean (s.d) TQmax was 5.2 (1.2) in control while 2.1 (1.8) in OAB (p = 0.001). Good correlation was noted with all parameters UI (r = 0.89); VVR (r = 0.87) and TQmax (r = 0.76); when all three were combined as an index the correlation was better (r = 0.95). Based on the beta coefficients an OAB Index [OABI = 8(UI)+9(VVR)+0.5(TQmax)] was proposed; ROC analysis revealed a cutoff of 12 (AUC 0.96). An OABI of <12 was proposed for diagnosing OAB, 12-15 for equivocal and >15 for normal children. In the validation study OABI had 93 % sensitivity; 100 % specificity; 100 % positive predictive value & 94 % negative predictive value. The overall accuracy was 97 %.

CONCLUSION

While current diagnosis of OAB is mainly subjective, the proposed OABI is an objective way of diagnosing OAB using uroflow parameters. OABI may also help to assess treatment response. Further larger studies are warranted.

Lack of expression of miR-29a/b1 impairs bladder function in male mice

Lower urinary tract symptoms (LUTS) refer to various urological diseases, and incomplete bladder emptying is common among affected patients. Etiology of LUTS is largely unknown, and investigations of LUTS suggest that bladder fibrosis contributes to pathogenesis of LUTS. MicroRNAs (miRNAs) are short (∼22 nucleotides), non-coding RNAs that repress target gene expression by a combination of mRNA degradation and translation inhibition. The miR-29 family is best known for its anti-fibrotic role in various organs. miR-29 was decreased in bladders of patients with outlet obstruction and a rat model of bladder outlet obstruction, suggesting that miR-29 may contribute to impaired bladder function subsequent to tissue fibrosis. We characterized bladder function in male mice lacking expression of MIR29A and MIR29B1 (miR-29a/b1). Lack of miR-29a/b1 resulted in severe urinary retention, increased voiding duration with reduced flow rate, and these mice failed to void or voided irregularly during anesthetized cytometry. Collagens and elastin were increased in bladders of mice lacking miR-29a/b1. These findings reveal an important role of mir-29 in bladder homeostasis and suggest therapeutic potential of miR-29 to improve symptoms in patients with LUTS.

[Special diagnostics in pediatric urology-Nuclear medicine diagnostics, advanced diagnostics for bladder voiding disorders and imaging diagnostics in the operating room : Tips for the practice part 2]

The diagnostics and treatment of pediatric urology patients in the clinical routine can be extremely challenging. In contrast to adult patients, the main concerns in the diagnostics of congenital diseases are time consuming examinations and limited options in addition to the expectations of the parents. The exact knowledge of the diagnostic possibilities in association with the correct interpretation of the indications is essential. Simple processes can be much more time consuming because of a lack of compliance, especially in very young children. Sonography is considered the standard for imaging in pediatric urology. Profound knowledge of the embryonal development and also physiological processes throughout childhood contribute to making the correct diagnosis. This article deals with the possibilities of nuclear medicine diagnostics, advanced diagnostics in bladder voiding disorders and finally imaging diagnostics in the pediatric urological operating room.

Bladder and voiding dysfunction in adolescents with anorexia nervosa: a novel finding and potential causes

PURPOSE

This study aimed to investigate the bladder capacity (BC) and bladder dynamics of adolescents with anorexia nervosa (AN).

METHODS

The participants consisted of 15 adolescents newly diagnosed with AN according to the DSM 5 criteria and in the acute weight loss period who were questioned about the symptoms of lower urinary tract (LUT) dysfunction. Functional bladder capacity (FBC) and voided volume with uroflowmetry were measured for each subject; the larger volume of the two was chosen for the bladder capacity. Uroflowmetry was used to obtain uroflow curves for the participants whose patterns were labeled as pathologic if they were outside the bell-shape.

RESULTS

Fourteen (93.3%) of the patients exhibited at least one of the LUT dysfunction symptoms (pathologic voiding symptom/urinary incontinence/pathologic uroflow pattern). BC was observed to increase in 86.6% (n = 13) of the patients. Eighty% of the patients (n = 12) showed pathological uroflow patterns. In patients with pathological uroflow patterns, which showed insufficiency of bladder contraction, assistance of abdominal muscles was needed during voiding.

CONCLUSION

The novel findings presented in this study are the increase of BC in adolescents with AN, the presence of at least one type of voiding or bladder dysfunction, and the pathology of uroflow patterns of most patients show that the bladder dynamics is affected in AN. The most important contribution of this study to the literature is that impaired bladder dynamics was determined to be a medical complication of AN.

LEVEL OF EVIDENCE

Case-control analytic study, Level III.

Can a quantitative means be used to predict flow patterns: Agreement between visual inspection vs. flow index derived flow patterns

INTRODUCTION

Uroflowmetry is a first-line tool in the evaluation of children with lower urinary tract symptoms. Unfortunately, there is a tremendous amount of intra- and interobserver variation in defining the shape of curves. Regrettably, one observer can see one flow as a tower and the other can call it a bell. Here lies the major flaw with the interpretation of uroflow shapes. Previously, we have shown that there is a good correlation between the calculated flow index (FI) and the shape of a flow curve (bell, tower and plateau) in normal children.

OBJECTIVE

Our hypothesis was to show that the FI-defined shapes were as good or better than the present system of grading flow curves. If so this would help remove subjectivity from the field of uroflow assessment and make studies objective and easily compared.

STUDY DESIGN

Consecutive uroflows of children who were being evaluated for lower urinary tract symptoms from two centers were reviewed and compared alongside those of presumed normal voiders; the shape of the curves were read by the same experienced readers at each institution. Only curves that were read as bell, plateau, and tower were compared with the curve patterns derived from the quantitative methods derived by one of the authors. FI was derived by taking the actual Qmax/estimated Qmax.

RESULTS

There were 591 males and 1039 females who had uroflow studies, of these 409 and 819, respectively were read as either bell, towers, or plateaus The highest kappa value for males was 0.71 (CI 0.64-0.79) using a 3 × 3 matrix indicating substantial agreement. In females the highest kappa was 0.52 (CI 0.46-0.59) in the group 2 patients using the receiver operating characteristic cutoffs but the 1 SD cutoff was close with a kappa value of 0.51, which indicates moderate agreement (Table).

DISCUSSION

Using the FI method we saw that there was substantial to moderate agreement using a quantitative method to define flow shapes based on the kappa values that were obtained in this study. The one fundamental flaw with shape determination in both visual and FI-derived methods is that the cutoffs are arbitrary since the visual defined shapes are the basis for the FI shapes.

CONCLUSION

Our findings clearly showed that a FI-derived method of defining shapes is as accurate as visual inspection or more depending on the study. The greatest disagreement occurs in those grey or transition zones between plateau, bell and tower. This system could be useful in removing much of the ambiguity and difficulty in reading flows.