Videourodynamic findings of lower urinary tract dysfunctions in men with persistent storage lower urinary tract symptoms after medical treatment

Current optimal pharmacologic therapies for overactive bladder

INTRODUCTION

Overactive bladder (OAB) is a common syndrome in adults. Current pharmacologic treatment includes antimuscarinic agents and β-3 adrenoceptor agonists. For non-responders to oral medication, intravesical injection of botulinum toxin A (BoNT-A) is an effective option. However, these treatments have potential adverse events and should be cautiously selected for appropriate patients. This review presents the recently published results of clinical trials and studies for patients with OAB and the underlying pathophysiology of OAB. Appropriate medical therapy based on pathophysiology of OAB is also presented.

AREAS COVERED

Literature search from Pubmed from 2001 to 2023 including clinical background, pharmacology, and clinical studies for OAB medications.

EXPERT OPINION

Treatment of OAB syndrome with any antimuscarinic or β-3 adrenoceptor agonist is feasible as a first-line approach. For patients with suboptimal therapeutic effect to full-dose antimuscarinics or mirabegron, combination with both drugs can improve efficacy. Intravesical BoNT-A 100-U injection provides therapeutic effects for refractory OAB. Patients who are refractory to initial pharmacotherapies should be investigated for the underlying pathophysiology; then an appropriate medication can be added, such as an α1-blocker or anti-inflammatory agents. Patient education about behavioral modification and therapies should always be provided with oral medication or BoNT-A injection for OAB patients.

Use of Urinary Biomarkers in Discriminating Interstitial Cystitis/Bladder Pain Syndrome from Male Lower Urinary Tract Dysfunctions

To analyze the urinary biomarkers in men with lower urinary-tract symptoms (LUTS) and identify interstitial cystitis/bladder pain syndrome (IC/BPS) from the other lower urinary-tract dysfunctions (LUTDs) by the levels of characteristic urinary biomarkers. In total, 198 men with LUTS were prospectively enrolled and urine samples were collected before intervention or medical treatment. Videourodynamic studies were routinely performed and the LUTDs were diagnosed as having bladder-outlet obstruction (BOO) such as bladder-neck dysfunction, benign prostatic obstruction, or poor relaxation of external sphincter (PRES); and bladder dysfunction such as detrusor overactivity (DO), hypersensitive bladder (HSB), and IC/BPS. Patients suspicious of IC/BPS were further confirmed by cystoscopic hydrodistention under anesthesia. The urine samples were investigated for 11 urinary inflammatory biomarkers including eotaxin, IL-6, IL-8, CXCL10, MCP-1, MIP-1β, RANTES, TNF-α, NGF, BDNF, and PGE2; and 3 oxidative stress biomarkers 8-OHdG, 8-isoprostane, and TAC. The urinary biomarker levels were analyzed between LUTD subgroups and IC/BPS patients. The results of this study revealed that among the patients, IC/BPS was diagnosed in 48, BOO in 66, DO in 25, HSB in 27, PRES in 15, and normal in 17. Patients with BOO had a higher detrusor pressure and BOO index than IC/BPS, whereas patients with IC/BPS, BOO, and DO had a smaller cystometric bladder capacity than the PRES and normal subgroups. Among the urinary biomarkers, patients with IC/BPS had significantly higher levels of eotaxin, MCP-1, TNF-α, 8-OHdG, and TAC than all other LUTD subgroups. By a combination of different characteristic urinary biomarkers, TNF-α, and eotaxin, either alone or in combination, had the highest sensitivity, specificity, positive predictive value, and negative predictive value to discriminate IC/BPS from patients of all other LUTD subgroups, BOO, DO, or HSB subgroups. Inflammatory biomarker MCP-1 and oxidative stress biomarkers 8-OHdG and TAC, although significantly higher in IC/BPS than normal and PRES subgroups, did not have a diagnostic value between male patients with IC/BPS and the BOO, DO, or HSB subgroups. The study concluded that using urinary TNF-α and eotaxin levels, either alone or in combination, can be used as biomarkers to discriminate patients with IC/BPS from the other LUTD subgroups in men with LUTS.

MRI and MR voiding cystourethrography in the evaluation of male primary bladder neck obstruction: preliminary experience

PURPOSE

Evaluation of male with primary bladder neck obstruction (PBNO) using MRI and MR voiding cystourethrography (MR-VCU) to study both anatomical aspects of bladder neck and urethral lumen.

METHODS

In this retrospective study 21 male patients (mean age 33 ± 14) with urodynamic diagnosis of PBNO and 5 healthy volunteers ((mean age 28 ± 2) as control group were enrolled. Both patients and control group underwent 1.5 T MRI. Sagittal and oblique coronal Turbo-Spin-Echo T2-weighted scans were performed. Only patients underwent MR voiding cystourethrography (MR-VCU) performed with T1-weighted spoiled 3D gradient-echo sagittal acquisitions. Bladder lumen was filled with contrast-material-enhanced urine. Blinded test by two radiologists was performed to evaluate causes of bladder outlet obstruction evaluating MR-VCU. Anatomical MRI features of both control group and patients were compared in consensus by senior radiologist and urologist using the analysis of variance (ANOVA) test.

RESULTS

MRI allowed evaluation of the bladder neck muscular structures. We found 4 groups of PBNO patients: 52% hypertrophy of posterior lip of bladder sphincter; 20% asymmetry of lateral portion of bladder sphincter; 14% bladder neck cyst; 14% showed normal aspect of bladder neck. Comparison between the control group and first and second PBNO groups was considered statistically significant (p < 0.05) with diagnostic accuracy of 87%. Only 13 patients (61%) were able to perform MR-VCU and radiologists always made the diagnosis of PBNO.

CONCLUSION

MRI together with MR-VCU provides useful anatomical and functional information in the study of bladder neck and urethral lumen. These preliminary results suggest that MRI could substitute for standard cystourethrogram in patients with PBNO.

Therapeutic Efficacy of Urethral Sphincter Injections of Platelet-Rich Plasma for the Treatment of Stress Urinary Incontinence due to Intrinsic Sphincter Deficiency: A Proof-of-Concept Clinical Trial

Purpose

The aim of this study was to investigate the efficacy of autologous platelet-rich plasma (PRP) in the treatment of stress urinary incontinence (SUI) due to intrinsic sphincter deficiency (ISD) refractory to medical treatment.

Methods

Thirty-five patients with SUI due to urodynamically proven ISD were prospectively enrolled. Five milliliters of PRP (2.5–5 times the platelet concentration in peripheral blood) was injected into the external sphincter at 5 sites; all patients received 4 injections at monthly intervals. The primary end-point was the change in SUI severity as assessed by a visual analogue scale (VAS of SUI). The secondary-endpoints were the Global Response Assessment score and changes in urodynamic parameters from baseline to 3 months after treatment.

Results

The mean age of patients was 68.7±12 years; the median duration of SUI was 4 years. Five patients had neurogenic SUI, while 30 had nonneurogenic SUI (21 with postprostatectomy incontinence, 6 with previous radical cystectomy, and 3 with other etiologies). Complete dryness was achieved in 7 patients (20.0%) while moderate improvement was observed in 14 (40.0%). The mean VAS of SUI score decreased significantly from 6.57±1.89 to 3.77±2.41 after treatment. The abdominal leak point pressure (ALPP) increased significantly from 98.3±55.8 to 157.3±79.3 cm H₂O. There was no increase of ALPP in neurogenic SUI and less increase of ALPP in patients with failed treatment outcomes. No perioperative adverse events or severe complications occurred.

Conclusions

Urethral PRP injection is safe and effective in increasing urethral resistance and improving SUI. PRP could be an alternative treatment modality for male and female patients with moderate SUI due to nonneurogenic causes.

Evaluation of surgical procedures of mouse urethra by visualization and the formation of fistula

Visualization of the surgically operated tissues is vital to improve surgical model animals including mouse. Urological surgeries for urethra include series of fine manipulations to treat the increasing number of birth defects such as hypospadias. Hence visualization of the urethral status is vital. Inappropriate urethral surgical procedure often leads to the incomplete wound healing and subsequent formation of urethro-cutaneous fistula or urethral stricture. Application of indocyanine green mediated visualization of the urethra was first performed in the current study. Indocyanine green revealed the bladder but not the urethral status in mouse. Antegrade injection of contrast agent into the bladder enabled to detect the urethral status in vivo. The visualization of the leakage of contrast agent from the operated region was shown as the state of urethral fistula in the current hypospadias mouse model and urethral stricture was also revealed. A second trial for contrast agent was performed after the initial operation and a tendency of accelerated urethral stricture was observed. Thus, assessment of post-surgical conditions of urogenital tissues can be improved by the current analyses on the urethral status.

Current management of refractory overactive bladder

Overactive bladder (OAB) is a common condition affecting one-sixth to one-fifth of the global population. The treatment of refractory OAB remains a challenge for urologists. Current treatment options include the use of combination therapy with antimuscarinic agents and beta-3 adrenoceptor agonists, and treating underlying curable disorders. Intravesical botulinum toxin type A (BoNT-A) injection, percutaneous tibial nerve stimulation, and sacral nerve stimulation are third-line management therapies suggested by the American Urological Association/Society of Urodynamics, Female Pelvic Medicine & Urogenital Reconstruction (AUA/SUFU) guidelines. In rare cases, more invasive surgical interventions can be considered after explaining the benefits and risks to the patients. Augmentation cystoplasty has a high success rate; however, it has also been associated with a high complication rate. In contrast, detrusor myomectomy is an easy procedure, but the treatment outcome remains controversial. Liposome-encapsulated BoNT-A is administered via bladder instillation, and promising results have been obtained in preliminary studies. More therapies are currently being investigated, and transient receptor potential vanilloid 1 antagonists may be new type of medication. Radiofrequency ablation and other targets for neuromodulation have also been studied; however, more evidence is needed to confirm their efficacy.

Role of videourodynamic study in precision diagnosis and treatment for lower urinary tract dysfunction

Lower urinary tract symptoms (LUTS) are complicated and cannot be used alone to diagnose lower urinary tract dysfunctions (LUTDs) and guide treatment. Patients with bladder outlet obstruction (BOO), impaired detrusor contractility, and hypersensitive bladder might present with voiding predominant symptoms, whereas patients with detrusor overactivity (DO), dysfunctional voiding, or BOO might also present with storage symptoms. To clearly identify the pathophysiology of LUTD, a comprehensive urodynamic study (UDS) including pressure flow and image during the storage and emptying phases, naming videourodynamic study (VUDS), is necessary. This study is especially mandatory in the diagnosis of (1) male LUTS refractory to medical treatment for benign prostatic hyperplasia, (2) female voiding dysfunction and urinary retention, (3) diagnosis of overactive bladder syndrome refractory to first-line medication, (4) management of female stress urinary incontinence and postoperative LUTS, (5) diagnosis and management of neurogenic LUTD, (6) pediatric urinary incontinence and enuresis, (7) geriatric urinary incontinence, and (8) recurrent bacterial cystitis. Although VUDS should not be used as a screening test for any LUTS, it should be considered when the initial management cannot relieve LUTS, or when invasive surgical procedure is planning to undertake for patients with refractory LUTS. VUDS should be recommended as the second-line investigation when the initial diagnosis and treatment based on the symptoms alone or noninvasive tests fail to improve LUTS.

Change of Detrusor Contractility in Patients with and without Bladder Outlet Obstruction at Ten or More Years of follow-up

To analyze the change of detrusor contractility by investigating urodynamic characteristics with long term follow-up. This study retrospectively reviewed 166 lower urinary tract symptoms patients without bladder outlet obstruction (BOO) and 63 patients with BOO who underwent repeated urodynamic studies at the first time and more than 10 years later. The urodynamic parameters, bladder contractility index (BCI), and BOO index (BOOI) were compared before and after. As time goes by, detrusor pressure at maximum flow rate (PdetQmax) significantly decreased and post-void residual (PVR) volume significantly increased in both men and women. Full sensation, urge sensation, voided volume, and BCI significantly decreased. We also compared men with and without BOO, PdetQmax, maximum flow rate (Qmax), voided volume, and BCI all significantly decreased in both groups without difference. PVR increased greater in men with BOO after >10 years significantly (p = 0.036). Women with detrusor overactivity (DO) under antimuscarinic showed no significant BCI change compared to patients without DO (p = 0.228). Detrusor contractility decreases in men and women after >10 years of follow-up. However, this finding suggests that patients with BOO or DO under adequate medical treatment, detrusor contractility is not aggravated over 10 or more years of follow-up.

Precision medicine in the diagnosis and treatment of male lower urinary tract symptoms suggestive of benign prostatic hyperplasia

Male lower urinary tract symptoms (LUTSs) are highly prevalent in men and the incidence increases with aging. The pathophysiology of male LUTSs might be bladder outlet dysfunctions such as bladder neck (BN) dysfunction, benign prostatic obstruction, and poor relaxation of external sphincter and bladder dysfunctions such as detrusor overactivity (DO), detrusor underactivity, DO, and inadequate contractility. Male LUTSs include voiding and storage symptoms, and precision diagnosis should not be done based on the symptoms alone. Videourodynamic study provides a thorough look at the bladder and bladder outlet and can clearly demonstrate the underlying pathophysiology when the initial medication fails to relieve LUTS. Medical treatment should be given based on the underlying pathophysiology of LUTS, and surgical intervention to remove prostate should only be performed when a definite bladder outlet obstruction due to prostatic obstruction has been confirmed by invasive urodynamic study.

Pathophysiology of refractory overactive bladder

Overactive bladder (OAB) is a common condition. The International Continence Society defines OAB as a symptom complex characterized by urgency with or without urge incontinence, usually with frequency and nocturia. The first-line treatment for OAB includes behavioral therapy, such as caffeine reduction, fluid intake modification, weight reduction, bladder training, and pelvic floor muscle training, as well as treatment with antimuscarinic or β₃ -adrenoceptor agonist medications. However, less than half of all cases achieve satisfactory outcomes following first-line treatment. Second-line therapy considered if satisfactory responses are not achieved after 8 to 12 weeks treatment with first-line therapy include intradetrusor botulinum toxin injection, neuromodulation, and surgical treatment. Patients with refractory OAB may have more severe symptoms or underlying pathophysiologies that were not resolved by the initial medication. The pathophysiologies of refractory OAB include occult neurogenic bladder, undetected bladder outlet obstruction, urethral-related OAB, urothelial dysfunction with aging, chronic bladder ischemia, chronic bladder inflammation, central sensitization, and autonomic dysfunction. This article discusses the possible pathophysiologies of refractory OAB.