Pressure-flow nomogram for women with lower urinary tract symptoms

A novel predictive model for noninvasively diagnosing bladder outlet obstruction in female patients based on clinical features and uroflowmetry parameters

OBJECTIVE

To develop and validate a simple prediction model to diagnose female bladder outlet obstruction (fBOO) because of the invasive nature of standard urodynamic studies (UDS) for diagnosing fBOO.

METHODS

We retrospectively analyzed the data of 728 women who underwent UDS at Tongji Hospital between 2011 and 2021. The definition of fBOO was Pdet.Qmax - 2.2 × Qmax > 5 (BOOIf > 5). Independent predictive factors of fBOO were determined by multivariable logistic regression analysis. These predictive factors were incorporated into a predictive model to assess the risk of fBOO.

RESULTS

Of the 728 patients, 249 (34.2%) were identified as having fBOO and these women were randomly assigned to two groups, a model development group and a model validation group. Multivariate logistic regression demonstrated that age, Qmax, flow time, and voiding efficiency were independent risk factors for fBOO. The predictive model of fBOO showed a satisfactory performance, with area under the curve being 0.811 (95% confidence interval [CI] 0.771-0.850, P < 0.001), which was confirmed to be 0.820 (95% CI 0.759-0.882, P < 0.001) with external validation. The calibration curve indicated that the predicted probability had an excellent correspondence to observed frequency. Decision curve analysis demonstrated a greater clinical net benefit compared with the strategies of treat all or treat none when the predicted risk was in a range of 3% and 75%.

CONCLUSION

A novel predictive model of fBOO was developed and validated based on clinical features and noninvasive test parameters in female patients with lower urinary tract symptoms. The model is a quick and easy-to-use tool to assess the risk of fBOO for urologists in their routine practice without an invasive UDS.

Dropped abdominal pressure at void in women

INTRODUCTION AND HYPOTHESIS

"Dropped p_abd at void" occurs when p_abd decreases below the previous resting pressure during voiding time. We sought clinical factors associated with this phenomenon and evaluated whether its correction modifies the urodynamic diagnosis.

METHODS

Retrospective cross-sectional study of non-neurological consecutive symptomatic women. The following definitions were used: "dropped p_abd at void": decrease in p_abd at Q_max ≥ 5 cmH₂O; bladder outflow obstruction (BOO) (p_detQmax ≥ 25 cmH₂O + Q_max ≤ 12 ml/s and female BOO index (p_detQmax - 2.2*Q_max) > 18; "low detrusor contraction strength": PIP1 (p_detQmax + Q_max) < 30. In patients with "dropped p_abd at void", p_detQmax was corrected.

RESULTS

A total of 360 women were analyzed. Ninety-five percent of the women had a variation in p_abd at Q_max between -13 and 53 cmH₂O. "Dropped p_abd at void" was found in 100 women (27.8%). History of stress urinary incontinence (SUI) surgery was significantly higher (p = 0.016) and symptoms of mixed urinary incontinence were significantly lower (p = 0.030) in patients with "dropped p_abd at void". On multivariate analysis only the history of SUI surgery maintained its significance (OR = 1.787 [95% CI: 1.058, 3.017], p = 0.030). When correcting p_detQmax in women with "dropped p_abd at void", 2 or 5 patients lost BOO diagnosis (depending on how it was diagnosed) and 7 patients gained a "low detrusor contraction strength" diagnosis.

CONCLUSIONS

Approximately one-quarter of women had "dropped p_abd at void", which was associated with a history of SUI surgery. Correction of p_detQmax would lead to a 2.5% to 3.33% diagnostic modification.

External validation of Solomon-Greenwell nomogram for female bladder outlet obstruction

AIM

There is no unified diagnostic standard for female bladder outlet obstruction (BOO) to date. The Solomon-Greenwell (S-G) nomogram was developed to indicate the probability of female BOO by performing a pressure-flow study, and the equation of the BOO Index in females (BOOIf) is PdetQmax - 2.2 × Qmax. We aimed to validate the diagnostic value of the S-G nomogram in female BOO.

MATERIALS AND METHODS

We retrospectively reviewed a videourodynamic study (VUDS) cohort in our institution. Between 2015 and 2020, 192 female patients underwent VUDS for lower urinary tract dysfunction (LUTD). We excluded patients with neurogenic LUTD (n = 30) and patients with no detrusor contraction and/or no void during VUDS (n = 51). The diagnosis of female BOO was based on the Nitti criteria (radiological evidence of urethral narrowing in the presence of a sustained detrusor pressure). BOOIf was calculated for each enrolled patient. The cutoff values of BOOIf were set at <0, >5, and >18 as the original S-G nomogram proposed. The sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of each threshold to diagnose female BOO were calculated.

RESULTS

Out of the 111 enrolled patients, 43 (38.7%) were diagnosed as having female BOO by VUDS. The most common etiology of female BOO was dysfunctional voiding (19/43, 44.2%), followed by primary bladder neck obstruction (PBNO, 15/43, 34.9%). When the cutoff value was <0 (low probability of obstruction), the sensitivity, specificity, PPV, and NPV were 90%, 91%, 92%, and 87%, respectively; when >5 (likely obstructed), the values were 79%, 96%, 92%, and 88%, respectively; and when >18 (obstruction almost certain), the values were 47%, 100%, 100%, and 75%, respectively. Fourteen of 15 PBNO patients would be classified as non-BOO if the cutoff value was >18. Six PBNO patients would not be diagnosed as female BOO if the threshold was >5.

CONCLUSION

A BOOIf <0 showed good diagnostic value for excluding female BOO. A BOOIf >18 had perfect specificity and PPV for diagnosing female BOO. However, the sensitivity of the S-G nomogram for detecting female BOO was unsatisfactory, especially for patients with PBNO. VUDS remains the examination of choice for patients with suspected female BOO.

Diagnostic Tests for Female Bladder Outlet Obstruction: A Systematic Review from the European Association of Urology Non-neurogenic Female LUTS Guidelines Panel

CONTEXT

Female bladder outlet obstruction (fBOO) is a relatively uncommon condition compared with its male counterpart. Several criteria have been proposed to define fBOO, but the comparative diagnostic accuracy of these remains uncertain.

OBJECTIVE

To identify and compare different tests to diagnose fBOO through a systematic review process.

EVIDENCE ACQUISITION

A systematic review of the literature was performed according to the Cochrane Handbook and Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) checklist. The EMBASE/MEDLINE/Cochrane databases were searched up to August 4, 2020. Studies on women ≥18 yr of age with suspected bladder outlet obstruction (BOO) involving diagnostic tests were included. Pressure-flow studies or fluoroscopy was used as the reference standard where possible. Two reviewers independently screened all articles, searched reference lists of retrieved articles, and performed data extraction. The risk of bias was assessed using Quality Assessment of Diagnostic Accuracy Studies (QUADAS-2).

EVIDENCE SYNTHESIS

Overall, 28 nonrandomised studies involving 10 248 patients were included in the qualitative analysis. There was significant heterogeneity regarding the characteristics of women included in BOO cohorts (ie, mixed cohorts including both anatomical and functional BOO). Pressure-flow studies ± fluoroscopy was evaluated in 25 studies. Transperineal Doppler ultrasound was used to evaluate bladder neck dynamics in two studies. One study tested the efficacy of transvaginal ultrasound. The urodynamic definition of fBOO also varied amongst studies with different parameters and thresholds used, which precluded a meta-analysis. Three studies derived nomograms using the maximum flow rate (Q_max) and voiding detrusor pressure at Q_max. The sensitivity, specificity, and overall accuracy ranges were 54.6-92.5%, 64.6-93.9%, and 64.1-92.2%, respectively.

CONCLUSIONS

The available evidence on diagnostic tests for fBOO is limited and heterogeneous. Pressure-flow studies ± fluoroscopy remains the current standard for diagnosing fBOO.

PATIENT SUMMARY

Evidence on tests used to diagnose female bladder outlet obstruction was reviewed. The most common test used was pressure-flow studies ± fluoroscopy, which remains the current standard for diagnosing bladder outlet obstruction in women. TAKE  HOME MESSAGE: The available evidence on diagnostic tests for female bladder outlet obstruction is limited and heterogeneous. The most common test used was video-urodynamics, which remains the current standard for diagnosing bladder outlet obstruction in women.

Clinical Guidelines for Female Lower Urinary Tract Symptoms (second edition)

The present article is an abridged English translation of the Japanese Clinical Guidelines for Female Lower Urinary Tract Symptoms (second edition), published in September 2019. These guidelines consist of a total of 212 pages and are unique worldwide in that they cover female lower urinary tract symptoms other than urinary incontinence. They contain two algorithms for "primary treatment" and "specialized treatment," respectively. These guidelines, consisting of six chapters, address a total of 26 clinical questions including: (i) treatment algorithms; (ii) what are female lower urinary tract symptoms?; (iii) epidemiology and quality of life; (iv) pathology and illness; (v) diagnosis; and (vi) treatment. When the patient's symptoms mainly involve voiding and post-micturition symptoms, specialized treatment should be considered. In the event of voiding symptoms concurrent with storage symptoms, residual urine should be measured; if the residual urine volume is <100 mL, then diagnosis and treatment for storage symptoms is prioritized, and if the volume is ≥100 mL, then specialized treatment should be considered. When storage symptoms are the primary condition, then the patient is subject to the primary treatment algorithm. Specialized treatment for refractory overactive bladder includes botulinum toxin injection and sacral nerve stimulation. For stress urinary incontinence, surgical treatment is indicated, such as urethral slings. The two causes of voiding symptoms and post-micturition symptoms are lower urinary tract obstruction and detrusor underactivity (underactive bladder). Mechanical lower urinary tract obstruction, such as pelvic organ prolapse, is expected to improve with surgery.

Urodynamic factors associated with the large capacity bladder and incomplete emptying after prolapse repair (2009-2015)

AIMS

To identify the clinical and urodynamic factors associated with the large capacity bladder and incomplete bladder emptying after prolapse repair.

METHODS

We identified 592 women who underwent anterior and/or apical prolapse repair at our institution from 2009 to 2015. Women were stratified by urodynamic capacity. The primary outcome was incomplete emptying at the longest follow-up (postvoid residual [PVR] > 200 mL). Data were analyzed in the Statistical Analysis System software.

RESULTS

Two hundred and sixty-six women (mean age, 61 years) had preoperative urodynamic tracings available for review. After surgery, there were 519 PVRs in 239 women recorded at up to 2949 days (mean, 396) and nine time points (median, 2; IQR, 1-3). The receiver operator curve for predicted probability of longest follow-up PVR greater than 200 mL (area under curve = 0.67) identified the 600 mL cutpoint which defined large capacity bladder. Large capacity bladders (capacity, >600 mL [n=79] vs ≤600 mL, [n=160]) had a mean: detrusor pressure at maximum flow (21 vs 22 cm H₂ O; P = 0.717), maximum flow rate (19 vs 17 mL/s; P = 0.148), significantly elevated PVR (202 vs 73 mL; P < 0.001), and significantly lower voiding efficiency (VE) (74 vs 82%, P < 0.05). Following prolapse repair, elevated PVR was associated with large capacity (PVR 101 vs 49 mL, P < 0.05). Large bladders had a two- to three-fold risk of longest follow-up PVR greater than 200 mL (14.3%-20.3% [capacity, >600 mL] vs 4.1%-7.0% [capacity, ≤600 mL]). VE was similar after surgery regardless of the capacity (87% vs 88%, P = 0.772).

CONCLUSIONS

The decision to pursue prolapse repair should be individualized and take into account, the bladder capacity and goals for PVR improvement after surgery.

Work Capacity of the Bladder During Voiding: A Novel Method to Evaluate Bladder Contractile Function and Bladder Outlet Obstruction

Background:

Work in voiding (WIV) of the bladder may be used to evaluate bladder status throughout urination rather than at a single time point. Few studies, however, have assessed WIV owing to the complexity of its calculations. We have developed a method of calculating work capacity of the bladder while voiding and analyzed the associations of bladder work parameters with bladder contractile function and bladder outlet obstruction (BOO).

Methods:

The study retrospectively evaluated 160 men and 23 women, aged >40 years and with a detrusor pressure at maximal flow rate (P_det Q_max) of ≥40 cmH₂O in men, who underwent urodynamic testing. The bladder power integration method was used to calculate WIV; WIV per second (WIV/t) and WIV per liter of urine voided (WIV/v) were also calculated. In men, the relationships between these work capacity parameters and P_det Q_max and Abrams-Griffiths (AG) number were determined using linear-by-linear association tests, and relationships between work capacity parameters and BOO grade were investigated using Spearman's association test.

Results:

The mean WIV was 1.15 ± 0.78 J and 1.30 ± 0.88 J, mean WIV/t was 22.95 ± 14.45 mW and 23.78 ± 17.02 mW, and mean WIV/v was 5.59 ± 2.32 J/L and 2.83 ± 1.87 J/L in men and women, respectively. In men, WIV/v showed significant positive associations with P_det Q_max (r = 0.845, P = 0.000), AG number (r = 0.814, P = 0.000), and Schafer class (r = 0.726, P = 0.000). Conversely, WIV and WIV/t showed no associations with P_det Q_max or AG number. In patients with BOO (Schafer class > II), WIV/v correlated positively with increasing BOO grade.

Conclusions:

WIV can be calculated from simple urodynamic parameters using the bladder power integration method. WIV/v may be a marker of BOO grade, and the bladder contractile function can be evaluated by WIV and WIV/t.

Recommendations for future development of contractility and obstruction nomograms for women. ICI-RS 2014

AIMS

At present, existing bladder outlet obstruction (BOO) nomograms for women are still not universally accepted. Moreover, only limited information is available regarding bladder contractility in women. The aim is to present the discussions and recommendations from the think tank session "Can we construct and validate contractility and obstruction nomograms for women?" held at the 2014 International Consultation on Incontinence-Research Society (ICI-RS) meeting in Bristol, UK.

METHODS

An overview of clinical significance, bladder mechanics and modelling, lack of existing nomograms for women, and development of new nomograms were presented and discussed in a multidisciplinary think tank session. This think tank session was based on a collaboration between physicians, engineers, and researchers and consensus was achieved on future research initiatives.

RESULTS AND CONCLUSIONS

Based on the think tank discussion, the ICI-RS panel put forward the following recommendations: the need to acquire normative age-matched data in women to define "normal" and "pathological" values of urodynamic parameters; the inclusion of additional clinical data in new nomograms and the use of this extra dimension to develop clinically applicable nomograms for female BOO and contractility; and finally, the need to take into account the variability of BOO in women when developing female bladder contractility nomograms.

Evaluation and management of male lower urinary tract symptoms: treatment patterns and guidelines in a correlation study among Polish urology consultants

INTRODUCTION

In March 2013, the European Association of Urology (EAU) released a new edition of the guidelines on management of male lower urinary tract symptoms (LUTS), including benign prostatic obstruction. The objective of this study was to evaluate how well the EAU guidelines have been implemented in day-to-day practice by Polish urologists.

MATERIAL AND METHODS

A structured questionnaire, which explored how urologists diagnose and manage male lower urinary tract symptoms, was emailed to all certified, actively practicing urologists from a list provided by the Polish Urological Association.

RESULTS

The questionnaire return rate was 33.7% (135/400). Overall, the median (quartile 1; quartile 3) frequency of correct answers was 65.0% (58.0%; 69.0%). Analysis of the association of availability and acceptance of the EAU guidelines with question answers showed no pattern. A multivariate regression model showed a positive correlation with regards to correct answers given in the survey and doctors' participation in international congresses (p = 0.018, r = 0.181). Basket analysis showed the strongest association for those who failed to correctly answer the questions regarding diagnosis of LUTS and overactive bladder (OAB) (support = 27.41%, confidence = 86.05%).

CONCLUSIONS

Although there is a significant degree of adherence to the 2013 EAU guidelines, some discrepancies between urologists' practice and the recommendations regarding diagnosis and treatment of male LUTS do exist. The data obtained provide valuable benchmarks and also identify possible interventions that may improve the standard of care in this population of patients.

Evaluation of obstructed voiding in the female: how close are we to a definition?

PURPOSE OF REVIEW

The difficulties of defining and evaluating bladder outlet obstruction (BOO) in the female patient have been described for several years. This review aims to examine recent literature to summarize progress in the area.

RECENT FINDINGS

Within the last 2 years, functional causes of female BOO have been summarized, new nomograms proposed, several case reports of different causes of BOO have been published and work on surgical outcomes and possible diagnostics reported.

SUMMARY

Women complain of voiding dysfunction because of different reasons. For clinical decision-making, and to evaluate different surgical procedures, finding a way of detecting and quantifying infravesical obstruction is immensely helpful. This review aims to clarify questions concerning definitions of BOO in women and provide an update on recent advances.

Urinary tract infections in pregnancy: old and new unresolved diagnostic and therapeutic problems

Urinary tract infections (UTIs) are common in pregnant women and pose a great therapeutic challenge, since the risk of serious complications in both the mother and her child is high. Pregnancy is a state associated with physiological, structural and functional urinary tract changes which promote ascending infections from the urethra. Unlike the general population, all pregnant women should be screened for bacteriuria with urine culture, and asymptomatic bacteriuria must be treated in every case that is diagnosed, as it is an important risk factor for pyelonephritis in this population. The antibiotic chosen should have a good maternal and fetal safety profile. In this paper, current principles of diagnosis and management of UTI in pregnancy are reviewed, and the main problems and controversies are identified and discussed.