The penile cuff test: A clinically useful non-invasive urodynamic investigation to diagnose men with lower urinary tract symptoms

MRI-based radiomic features of the urinary bladder wall identify patients with moderate-to-severe international prostate symptom score

BACKGROUND

The International Prostate Symptom Score (IPSS) is a patient-reported measurement to assess the lower urinary tract symptoms of bladder outlet obstruction. Bladder outlet obstruction induces molecular and morphological alterations in the urothelium, suburothelium, detrusor smooth muscle cells, detrusor extracellular matrix, and nerves. We sought to analyze MRI-based radiomics features of the urinary bladder wall and their association with IPSS.

METHOD

In this retrospective study, 87 patients who had pelvic MRI scans were identified. A biomarker discovery approach based on the optimal biomarker (OBM) method was used to extract features of the bladder wall from MR images, including morphological, intensity-based, and texture-based features, along with clinical variables. Mathematical models were created using subsets of features and evaluated based on their ability to discriminate between low and moderate-to-severe IPSS (less than 8 vs. equal to or greater than 8).

RESULTS

Of the 7,666 features per patient, four highest-ranking optimal features were derived (all texture-based features), which provided a classification accuracy of 0.80 with a sensitivity, specificity, and area under the receiver operating characteristic curve of 0.81, 0.81, and 0.87, respectively.

CONCLUSION

A highly independent set of urinary bladder wall features derived from MRI scans were able to discriminate between patients with low vs. moderate-to-severe IPSS with accuracy of 80%. Such differences in MRI-based properties of the bladder wall in patients with varying IPSS's might reflect differences in underlying molecular and morphological alterations that occur in the setting of chronic bladder outlet obstruction.

Bladder wall thickness measured by CT can predict bladder outlet obstruction in men: a retrospective cohort study

PURPOSE

To evaluate whether bladder wall thickness (BWT) measured by CT can be used to predict bladder outlet obstruction in men with low urinary tract symptoms (LUTS).

METHODS

From 2015 to 2018, a total of 120 men with lower urinary tract symptoms who underwent both urodynamic studies and CT tests of the lower abdomen or pelvis were involved. Bladder wall thickness values were measured by CT scanning.

RESULTS

Based on the urodynamic studies, 120 men were categorized into two groups, including 70/120 men (58.3%) in the bladder outlet obstruction (BOO) group and 50/120 men (41.7%) in the non-BOO group. The mean BWT was thicker in the BOO group than in the non-BOO group (3.87 vs. 2.75 mm, p < 0.001). The mean maximum bladder capacity (MBC) was lower in the BOO group than in the non-BOO group (263.42 vs. 308.96 ml, p < 0.001). The mean detrusor pressure at maximum urinary flow rate (PdetQmax) was higher in the patients in the BOO group than in those in the non-BOO group (102.28 vs. 49.25 cmH₂O, p < 0.001). The ROC curve showed that BWT was a good predictor with an AUC of 0.855 (95% CI 0.785-0.924, p < 0.001). At the cutoff value of 3.20 mm, the predictive sensitivity of BWT for BOO was 72.9%, and the specificity was 90%.

CONCLUSION

Increased bladder wall thickness was correlated with bladder outlet obstruction in men with LUTS. Bladder wall thickness measured by CT scans may be a noninvasive parameter to predict bladder outlet obstruction in men with LUTS.

Use of the penile cuff test to diagnose bladder outlet obstruction: A systematic review and meta-analysis

PURPOSE

Among noninvasive modalities for assessing bladder outlet obstruction (BOO), the penile cuff test (PCT) is the most used in clinical practice. The purpose of this review was to evaluate the performance of PCT in diagnosing and managing BOO.

MATERIALS AND METHODS

PubMed, Scopus, CINAHL, Embase, Cochrane Library, and Web of Science were searched for studies investigating use of PCT for BOO. Studies evaluating diagnostic parameters, inter-observer agreements, or treatment outcomes using PCT were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses protocol was followed (PROSPERO ID: CRD42022300047). A proportional meta-analysis was done for diagnostic accuracy proportions. The Egger's and the Begg-Mazumdar rank-correlation tests were used to assess publication bias. Risk of bias was assessed using the Gradings of Recommendations, Assessment, Development, and Evaluations (GRADE) criteria.

RESULTS

Of the 272 articles retrieved, 17 were included in qualitative synthesis and meta-analysis was performed on five studies (comprising 448 patients). Two studies evaluating inter-observer agreement demonstrated 95% agreement and five studies evaluating procedures reported a 66%-80% surgical success rate on obstructed patients using PCT. From the proportional meta-analysis, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 0.85 (95% CI 0.71-0.95) 0.78 (95% CI 0.67-0.87), 0.74 (95% CI 0.52-0.91), and 0.87 (95% CI 0.73-0.96), respectively. Publication bias was noted for PPV but not for sensitivity, specificity, or NPV. Based on the GRADE criteria, there were two low, six moderate, and nine high-quality studies.

CONCLUSIONS

PCT performs sufficiently in diagnosing and managing BOO. However, due to variability in obstruction criteria assessment, more studies comparing diagnostic criteria are warranted.

Minimally invasive measurement of vesical pressure for diagnosis of infravesical obstruction

AIMS

This study was focused on the clinical test of an improved and portable version of a previously described urethral connector (UC), designed for minimally invasive measurement of vesical pressure and diagnosis of infravesical obstruction in men.

METHODS

The conventional pressure-flow study (PFS) and the test with the new version of UC were applied to individuals reporting lower urinary tract symptoms (LUTS), who were then classified as obstructed or non-obstructed/equivocal based on the bladder outlet obstruction index (BOOI) from PFS data. Two-way analysis of variance was used to compare the values of urine flow rate and vesical pressure between methods and diagnoses.

RESULTS

Vesical pressure and urine flow values were not significantly different between methods (P > 0.05), while the former was greater in the group classified as obstructed.

CONCLUSION

The present results showed that the UC test can support the diagnosis of infravesical obstruction in a comparable way as that of the conventional urodynamic method, however with the advantages of simplicity and minimal invasiveness, having thus the potential to be an alternative method for long term follow-up of individuals reporting LUTS.

Simple Modification of the Bladder Outlet Obstruction Index for Better Prediction of Endoscopically-Proven Prostatic Obstruction: A Preliminary Study

Purpose

The bladder outlet obstruction index (BOOI), also known as the Abrams-Griffiths (AG) number, is the most widely used index for predicting BOO. However, the obstructed prostatic urethra determined by the BOOI is often inconsistent with endoscopically-proven obstruction. We assessed abdominal straining pattern as a novel parameter for improving the prediction of BOO.

Materials and Methods

We retrospectively reviewed the pressure-flow studies (PFS) and cystourethroscopy in 176 BPH/LUTS patients who were unresponsive to medical therapy. During PFS, some groups of patients tried to urinate with abdominal straining, which can increases intravesical pressure and underestimate BOOI theoretically. Accordingly, the modified BOOI was defined as (P_detQ_max+ΔP_abd)-2Q_max.

Results

Ultimately, 130 patients were eligible for the analysis. In PFS, ΔP_abd (P_abdQ_max-initial P_abd) was 11.81±13.04 cmH₂O, and it was 0–9 cmH₂O in 75 (57.7%), 10–19 cmH₂O in 23 (17.7%) and ≥20 cmH₂O in 32 (24.6%) patients. An endoscopically obstructed prostatic urethra in 92 patients was correctly determined in 47 patients (51.1%) by the original BOOI versus 72 patients (78.3%) based on the modified BOOI. Meanwhile, an “unobstructed” urethra according to the original BOOI was present in 11 patients (12.0%), whereas according to the modified BOOI, only 2 (2.1%) would be labeled as “unobstructed”. In receiver operating characteristic curves, the area under the curve was 0.906 using the modified BOOI number versus 0.849 in the original BOOI (p<0.05).

Conclusions

The change in abdominal pressure was correlated with endoscopically-proven obstruction. Our simple modification of the BOOI on the basis of this finding better predicted bladder outlet obstruction and, therefore, should be considered when evaluating BOO in patients with LUTS/BPH.

The role of noninvasive penile cuff test in patients with bladder outlet obstruction

PURPOSE

The aim of this study was to compare the penile cuff test (PCT) and standard pressure-flow study (PFS) in patients with bladder outlet obstruction.

MATERIALS AND METHODS

A total of 58 male patients with moderate to severe lower urinary tract symptoms (LUTS) were selected. Seven patients were excluded; thus, 51 patients were finally enrolled. Each of the patients underwent a PCT and a subsequent PFS. The sensitivity (SE), specificity (SP), positive predictive value (PPV), negative predictive value (NPV), and likelihood ratio were calculated. Chi-square and Fisher exact test were used to evaluate relationships between PCT results and maximal urine flow (Qmax); a p<0.05 was considered statistically significant.

RESULTS

The mean (±standard deviation) age of the study group was 65.5±10.4 years. Overall, by use of the PCT, 24 patients were diagnosed as being obstructed and 27 patients as unobstructed. At the subsequent PFS, 16 of the 24 patients diagnosed as obstructed by the PCT were confirmed to be obstructed, 4 were diagnosed as unobstructed, and the remaining 4 patients appeared equivocal. Of the 27 patients shown to be unobstructed by the PCT, 25 were confirmed to not be obstructed by PFS, with 13 equivocal and 12 unobstructed. Two patients were diagnosed as being obstructed. For detecting obstruction, the PCT showed an SE of 88.9% and an SP of 75.7%. The PPV was 66.7% and the NPV was 93%.

CONCLUSIONS

The PCT is a beneficial test for evaluating patients with LUTS. In particular, this instrument has an acceptable ability to reject obstruction caused by benign prostatic hyperplasia.