The effect of posture and repetition on urodynamic parameters: A prospective randomized study

Excluding confusable diseases in patients with presumptive diagnosis of interstitial cystitis: A large patient cohort study

OBJECTIVE

To analyze the results of excluding confusable diseases in patients with a presumptive diagnosis of interstitial cystitis (IC).

METHODS

We retrospectively reviewed the electronic medical records of consecutive patients with IC between October 2005 and December 2019.

RESULTS

Patients with pelvic pain underwent an initial workup. Of these, 646 patients (164 men, 25.4%; 482 women, 74.6%) underwent observational cystoscopy under the suspicion of IC. Fourteen patients had genitourinary tract malignancies (2.2%) (bladder cancer, n = 13; prostate cancer, n = 1). Of the 13 patients with bladder cancer, three were diagnosed during initial observation cystoscopy. The remaining 10 patients were diagnosed during subsequent follow-up cystoscopic surgery. Urinary tuberculosis was identified in seven (1.1%) of 646 patients during the examination. Five (0.8%) of the six patients with suspected urinary tuberculosis at baseline imaging were positive for tuberculosis in the acid-fast bacillus test. One patient developed tuberculous granulomas in the bladder tissue after a cystectomy for intractable pelvic pain.

CONCLUSION

Our results show that continuous efforts to rule out bladder tumors or tuberculosis are still essential in the follow up of patients with suspected IC, even if these diseases are not excluded at the initial examination. Imaging studies are necessary to rule out tuberculosis.

Impact of patient position on cystometric parameters in pediatric patients with neurogenic bladder: A prospective study

AIMS

Urodynamic studies (UDSs) play a crucial role in evaluating lower urinary tract function in pediatric patients with neurogenic bladder. However, the influence of patient position on urodynamic parameters in this population remains understudied. This study aims to investigate the effect of patient position on urodynamic results in children with neurogenic bladder.

METHODS

A prospective study was conducted with 50 pediatric patients diagnosed with neurogenic bladder. Urodynamic recordings were obtained during a single session, with the first two fillings in the supine position and the third filling in the sitting position. Urodynamic parameters assessed included detrusor overactivity (DO), maximum detrusor pressure (MDP), cystometric bladder capacity (CBC), compliance (C), detrusor leak point pressure (DLPP), and bladder volume at the moment of incontinence (DLPV).

RESULTS

Patient position did not significantly influence CBC, DO, C, and DLPV (p > 0.05). However, there were significant differences in MDP and DLPP between the supine and sitting positions (p < 0.05), with higher values observed in the supine position.

CONCLUSIONS

These findings highlight the importance of considering the patient's position when interpreting urodynamic results and making treatment decisions for children with neurogenic bladder. The higher MDP and DLPP values in the supine position may have clinical implications for assessing upper urinary tract integrity and treatment planning. However, further research is needed to understand the underlying mechanisms and generalize these findings to broader patient populations.

Reflex voiding in rat occurs at consistent bladder volume regardless of pressure or infusion rate

AIMS

The central nervous system (CNS) regulates lower urinary tract reflexes using information from sensory afferents; however, the mechanisms of this process are not well known. Pressure and volume were measured at the onset of the guarding and micturition reflexes across a range of infusion rates to provide insight into what the CNS is gauging to activate reflexes.

METHODS

Female Sprague Dawley rats were anesthetized with urethane for open outlet cystometry. A set of 10 infusion rates (ranging 0.92-65.5 mL/h) were pseudo-randomly distributed across 30 single-fill cystometrograms. Bladder pressure and external urethral sphincter electromyography were used for the determination of the onset of the micturition and guarding reflexes, respectively. The bladder volume at the onset of both reflexes was estimated from the total infusion rate during a single fill.

RESULTS

In response to many single-fill cystometrograms, there was an increased volume the bladder could store without a significant increase in pressure. Volume was adjusted for this effect for the analysis of how pressure and volume varied with infusion rate at the onset of the micturition and guarding reflexes. In 25 rats, the micturition reflex was evoked at similar volumes across all infusion rates, whereas the pressure at micturition reflex onset increased with increasing infusion rates. In 11 rats, the guarding reflex was evoked at similar pressures across infusion rates, but the volume decreased with increasing infusion rates.

CONCLUSIONS

These results suggest that the CNS is interpreting volume from the bladder to activate the micturition reflex and pressure from the bladder to activate the guarding reflex.

Development of Decision Support Formulas for the Prediction of Bladder Outlet Obstruction and Prostatic Surgery in Patients With Lower Urinary Tract Symptom/Benign Prostatic Hyperplasia: Part II, External Validation and Usability Testing of a Smartphone App

PURPOSE

We aimed to externally validate the prediction model we developed for having bladder outlet obstruction (BOO) and requiring prostatic surgery using 2 independent data sets from tertiary referral centers, and also aimed to validate a mobile app for using this model through usability testing.

METHODS

Formulas and nomograms predicting whether a subject has BOO and needs prostatic surgery were validated with an external validation cohort from Seoul National University Bundang Hospital and Seoul Metropolitan Government-Seoul National University Boramae Medical Center between January 2004 and April 2015. A smartphone-based app was developed, and 8 young urologists were enrolled for usability testing to identify any human factor issues of the app.

RESULTS

A total of 642 patients were included in the external validation cohort. No significant differences were found in the baseline characteristics of major parameters between the original (n=1,179) and the external validation cohort, except for the maximal flow rate. Predictions of requiring prostatic surgery in the validation cohort showed a sensitivity of 80.6%, a specificity of 73.2%, a positive predictive value of 49.7%, and a negative predictive value of 92.0%, and area under receiver operating curve of 0.84. The calibration plot indicated that the predictions have good correspondence. The decision curve showed also a high net benefit. Similar evaluation results using the external validation cohort were seen in the predictions of having BOO. Overall results of the usability test demonstrated that the app was user-friendly with no major human factor issues.

CONCLUSIONS

External validation of these newly developed a prediction model demonstrated a moderate level of discrimination, adequate calibration, and high net benefit gains for predicting both having BOO and requiring prostatic surgery. Also a smartphone app implementing the prediction model was user-friendly with no major human factor issue.

Development of Decision Support Formulas for the Prediction of Bladder Outlet Obstruction and Prostatic Surgery in Patients With Lower Urinary Tract Symptom/Benign Prostatic Hyperplasia: Part I, Development of the Formula and its Internal Validation

PURPOSE

As the elderly population increases, a growing number of patients have lower urinary tract symptom (LUTS)/benign prostatic hyperplasia (BPH). The aim of this study was to develop decision support formulas and nomograms for the prediction of bladder outlet obstruction (BOO) and for BOO-related surgical decision-making, and to validate them in patients with LUTS/BPH.

METHODS

Patient with LUTS/BPH between October 2004 and May 2014 were enrolled as a development cohort. The available variables included age, International Prostate Symptom Score, free uroflowmetry, postvoid residual volume, total prostate volume, and the results of a pressure-flow study. A causal Bayesian network analysis was used to identify relevant parameters. Using multivariate logistic regression analysis, formulas were developed to calculate the probabilities of having BOO and requiring prostatic surgery. Patients between June 2014 and December 2015 were prospectively enrolled for internal validation. Receiver operating characteristic curve analysis, calibration plots, and decision curve analysis were performed.

RESULTS

A total of 1,179 male patients with LUTS/BPH, with a mean age of 66.1 years, were included as a development cohort. Another 253 patients were enrolled as an internal validation cohort. Using multivariate logistic regression analysis, 2 and 4 formulas were established to estimate the probabilities of having BOO and requiring prostatic surgery, respectively. Our analysis of the predictive accuracy of the model revealed area under the curve values of 0.82 for BOO and 0.87 for prostatic surgery. The sensitivity and specificity were 53.6% and 87.0% for BOO, and 91.6% and 50.0% for prostatic surgery, respectively. The calibration plot indicated that these prediction models showed a good correspondence. In addition, the decision curve analysis showed a high net benefit across the entire spectrum of probability thresholds.

CONCLUSIONS

We established nomograms for the prediction of BOO and BOO-related prostatic surgery in patients with LUTS/BPH. Internal validation of the nomograms demonstrated that they predicted both having BOO and requiring prostatic surgery very well.