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

Detrusor Overactivity After Partial Bladder Outlet Obstruction Is Associated With High Urinary Adenosine Triphosphate Levels in Female Wistar Rats

PURPOSE

Bladder outlet obstruction (BOO) commonly causes detrusor overactivity (DO). In this study, a post hoc analysis of previous obtained data, we investigate if DO occurring in initial phases of BOO is associated with changes in urinary adenosine triphosphate (ATP) levels.

METHODS

Adult female Wistar rats were submitted to partial BOO (pBOO) or to sham obstruction. Cystometry was performed at 3 or 15 days after pBOO and saline voided was collected for ATP determination. Normality was tested using Shapiro-Wilk test. The mean frequency of voiding contractions (VCs) of the sham-operated animals at 15 days after surgery, plus or minus 3 standard deviations, was used to represent the normal range. Statistical analyses were performed using the chi-square and Mann-Whitney tests.

RESULTS

DO was indicated by a VC frequency greater than or equal to 0.9 VCs/min. DO was observed in 63% of animals at 3 days and in 33% at 15 days following pBOO. ATP levels were significantly higher in rats with DO compared to those without DO.

CONCLUSION

The DO phenotype, occurring in the initial phases of BOO, is associated with comparatively high urinary ATP levels.

Effect of bladder filling volume on detrusor contractility in men with bladder outlet obstruction

INTRODUCTION

Bladder outlet obstruction alters detrusor contractility, reducing the bladder's ability to respond to large filling with a risk of urinary retention. The objective was to assess the effect of bladder filling volume on detrusor contractility in men with bladder outlet obstruction.

METHODS

A prospective multicenter study in two pelviperineology departments. Male patients eligible for urodynamics (IPSS score > 7) were included from January to July 2022. In case of absence of bladder outlet obstruction on pressure-flow studies, they were secondarily excluded. The primary endpoint was the maximum isometric detrusor pressure during a stop-test, corresponding to detrusor contractility, measured at 3 filling volumes (50%, 75%, and 100% of cystometric capacity).

RESULTS

Fifty-two patients performed urodynamics, of whom 12 were excluded because of lack of obstruction or inability to perform the stop-test. Detrusor contractility was significantly higher for a 75% bladder filling than 50% and for a 75% filling than 100%, with a mean difference of 19.5; confidence interval (CI) 95% [14.3; 24.8] and 12.2; CI 95% [6.9; 17.5] cmH₂ O respectively (p < 0,01).

CONCLUSION

In case of bladder outlet obstruction in men, detrusor contractility depends on bladder filling volume, with reduced contractility when the bladder was underfilled or overfilled. This phenomenon could help to explain the mechanisms of urinary retention in men with bladder outlet obstruction.

Application of En Bloc and Urethral Mucosal Flap Sparing Techniques Improve the Functional Outcomes in Holmium Laser Enucleation of Prostate: A Retrospective Case Control Study

The purpose of the study was to study the feasibility of holmium laser enucleation of prostate (HoLEP) with en bloc and urethral mucosal flap sparing technique in treating benign prostatic hyperplasia (BPH) patients and to evaluate the influence of this modified technique on urinary function. A cohort of 188 BPH patients underwent HoLEP from June 2017 to October 2019. Among them, 92 patients underwent conventional en bloc HoLEP and the other 96 patients underwent HoLEP with en bloc and urethral mucosal flap sparing techniques. The basic characteristics, the volume of the prostate, urodynamic data, and perioperative parameters were recorded for comparison. The outcome parameters include international prostate symptom score (IPSS), maximum urinary flow rate (Qmax), post-voiding residual (PVR), quality of life score (QoL), and incidence of de novo stress urinary incontinence (SUI). The basic characteristics were equivalent in both groups. All HoLEP procedures were smoothly carried out. The perioperative complications were low and did not show a significant difference. The follow-up period was 12 months or longer. IPSS, Qmax, QoL, and PVR were improved postoperation in both groups. There was no statistical difference in the parameters between the two groups. When considering a postoperative SUI, the occurrence of short-term and long-term SUI in the modified HoLEP group was significantly less than those in the conventional HoLEP group (p < 0.05). In summary, HoLEP by using en bloc and urethral mucosal flap sparing technique is a safe and effective treatment for BPH patients, especially in preventing postoperative SUI.

The association between the parameters of uroflowmetry and lower urinary tract symptoms in prostate cancer patients after robot-assisted radical prostatectomy

OBJECTIVE

To investigate changes in uroflowmetry parameters in men undergoing robot-assisted radical prostatectomy (RARP) for prostate cancer.

MATERIALS AND METHODS

Four hundred and twenty-eight patients received uroflowmetry testing before and after RARP from November 2011 to December 2018. Clinicopathological data, including age, initial prostate-specific antigen (PSA), prostate volume, clinical stage, body mass index (BMI), uroflowmetry parameters, and core lower urinary tract symptom scores (CLSS) were retrospectively obtained from clinical records. Changes in uroflowmetry parameters were analyzed for statistical predictors and effects on post-operative outcomes.

RESULTS

A significant increase in maximum flow rate (MFR) and decreases in voided volume (VV) and post-void residual urine (PVR) were seen. In multivariate analysis, age was a negative predictor of MFR increase, while prostate volume was a positive predictor of PVR decrease and MFR increase. VV decrease led to worse incontinence symptoms, while PVR decrease and MFR increase led to improvement in voiding symptoms such as slow stream and straining. Continence recovery curves showed that VV decrease were associated with a delay in continence recovery.

CONCLUSIONS

Significant changes were seen in uroflowmetry results after RARP, each parameter directly related to urinary symptoms. In particular, VV decrease was associated with a worsening of incontinence symptoms and continence recovery.

Urodynamic findings in patients with nocturia and their associations with patient characteristics

INTRODUCTION

This study identified associations between lower urinary tract pathology confirmed on urodynamic testing, baseline characteristics, and symptoms for adults with nocturia. Nocturia frequency was examined for predictors.

METHODS

This retrospective study from 2012-2019 analyzed adult patients with nocturia (waking to void ≥2x/night) referred for urodynamic testing (UDS). Data on baseline characteristics, symptoms, UDS parameters, and lower urinary tract pathology were recorded. Males and females were analyzed separately, and univariable analyses were conducted, stratified by lower urinary tract pathology. Multivariable regression models were fit. Nocturia frequency was analyzed for associations with clinical parameters.

RESULTS

Altogether, 372 patients were included (159 men and 213 women). More men had detrusor overactivity (DO) (p<0.001) and bladder outlet obstruction (BOO) (p<0.001). DO was associated with storage symptoms (odds ratio [OR] 5.19, p<0.001), in addition to older age (p=0.009) and being male (p<0.001). Detrusor under-activity (DU) was associated with voiding symptoms (OR 1.92, p=0.004), older age (p<0.001), and being female (p=0.018). BOO was associated voiding symptoms (OR 2.09, p=0.023), younger age (p=0.018), and being male (p<0.001). The quantity of lower urinary tract symptoms was associated with DU and DO. Nocturia frequency was not associated with baseline variables or underlying pathologies. A substantial number of patients were diagnosed with DU alone (n=69, 18.7%) or associated with other diagnoses (n=108, 29.3%).

CONCLUSIONS

Careful assessment of risk factors and symptoms may help identify underlying lower urinary tract pathology for adults with nocturia. DU is found in a significant proportion of patients with nocturia, a previously under-reported result.

The relationship between bladder storage function and frequent micturition after TURP

PURPOSE

To investigate the relationship between preoperative bladder function and frequent micturition after transurethral resection of prostate in patients with benign prostatic hyperplasia.

METHODS

We retrospectively included 80 eligible patients aged 54-87 years (mean age 69.8 years) who underwent transurethral resection of the prostate at our hospital from January 2019 to October 2021. Patients were divided into detrusor overactivity positive and negative groups, and according to bladder compliance, they were divided into: low (G1), normal (G2), and high (G3) bladder compliance groups.

RESULTS

The incidence and score of postoperative frequent micturition in the detrusor overactivity positive group were higher than those in the detrusor overactivity negative group. The incidence and score of postoperative frequent micturition in the low bladder compliance group were higher than those in the normal and high bladder compliance groups. There was no significant difference in the score of frequent micturition between the normal and high bladder compliance groups. Multivariate logistic regression analysis indicated that frequent micturition was significantly correlated with detrusor overactivity, bladder compliance, maximum cystometric capacity, and maximum flow rate.

CONCLUSION

This study confirmed that patients with abnormal bladder storage functions (detrusor instability and low bladder compliance) before transurethral resection of the prostate were likely to have frequent and severe urination after transurethral resection of the prostate. Therefore, preoperative urodynamic examination to evaluate the urinary storage function of patients with benign prostatic hyperplasia is of great significance to predict the occurrence and degree of postoperative frequent micturition.

Effect of superselective prostatic artery embolization on benign prostatic hyperplasia

PURPOSE

To investigate the safety and effectiveness of superselective prostatic artery embolization (PAE) in patients with benign prostatic hyperplasia (BPH).

METHODS

Sixty-five patients diagnosed with BPH in Fujian Provincial Hospital between December 2014 and July 2019 were included. Patients with ineffective drug treatment after 6 months, who refused surgery, or who were unsuitable for surgery were included. We observed postoperative complications, followed up at 1, 3, and 6 months, compared clinical symptoms, and monitored changes in prostate-specific antigen (PSA) and prostatic volume (PV) before and after treatment.

RESULTS

Of the 65 patients, 58 (89.23%) successfully received PAE; 44 and 14 bilateral and unilateral embolization, respectively. Clinical efficacy was 94.83% (55/58) after the 6-month follow-up. Postoperative PV, International Prostate Symptom Score, quality of life, maximum flow rate, and post-void residual significantly improved after 6 months (P < 0.05). One month after PAE, the serum total PSA increased by 1.47 (10.84/7.37) times and dropped 3 months later to a level lower than that before surgery (P < 0.05). Six months after PAE, the degree of relief from obstructive symptoms was more apparent than that of irritative symptoms. No serious complications were observed after PAE.

CONCLUSION

PAE was safe and effective for the treatment of BPH. The efficacy of bilateral PAE was better than that of unilateral PAE.

Novel CFD modeling approaches to assessing urine flow in prostatic urethra after transurethral surgery

Assessment of the pressure and velocity of urine flow for different diameter ratios of prostatic urethra (RPU) after transurethral surgery using computational fluid dynamics (CFD). A standardized and idealized two-dimensional CFD model after transurethral surgery (CATS-1st) was developed for post-surgery mid-voiding. Using CATS-1st, 210 examples were amplified according to an array of size [3][5][14], which contained three groups of longitudinal diameters of prostatic urethra (LD-PU). Each of these groups contained five subgroups of transverse diameters of the bladder neck (TD-BN), each with 14 examples of transverse diameters of PU (TD-PU). The pressure and velocity of urine flow were monitored through flow dynamics simulation, and the relationship among RPU-1 (TD-PU/TD-BN), RPU-2 (RPU-1/LD-PU), the transverse diameter of the vortex, and the midpoint velocity of the external urethral orifice (MV-EUO) was determined. A total of 210 CATS examples, including CATS-1st examples, were analyzed. High (bladder and PU) and medium/low (the rest of the urethra) pressure zones, and low (bladder), medium (PU), and high (the rest of the urethra) velocity zones were determined. The rapid changes in the velocity were concentrated in and around the PU. Laminar flow was present in all the examples. The vortices appeared and then gradually shrank with reducing RPU on both the sides of PU in 182 examples. In the vortex examples, minimum RPU-1 and RPU-2 reached close to the values of 0.79 and 0.02, respectively. MV-EUO increased gradually with decreasing RPU. In comparison to the vortex examples, the non-vortex examples exhibited a significantly higher (p < 0.01) MV-EUO. The developed CFD models (CATS) presented an effective simulation of urine flow behavior within the PU after transurethral surgery for benign prostatic hyperplasia (BPH). These models could prove to be useful for morphological repair in PU after transurethral surgery.

Pathogenesis evidence from human and animal models of detrusor underactivity

Detrusor underactivity (DU) is a common urodynamic diagnosis in patients with lower urinary tract symptoms and large post-voiding residual volume. Animal and human studies showed the possible etiologies of DU include central or peripheral nerve injury, bladder outlet obstruction, chronic ischemia, aging, diabetes mellitus, and sympathetic inhibition of micturition reflex. Evidence from animal and human DU studies with various etiologies revealed highly similar gross and histological characteristics in the bladders, including increased bladder weight, bladder wall thickening, inflammation, collagen deposition, and fibrosis. In electron microscopy, smooth muscle destruction, swollen mitochondria, decreased nerve innervation, caveolae, and umbrella cell fusiform vesicles were noted in the DU bladders. Most animal DU models demonstrate detrusor contractility changes from compensatory to the decompensatory stage, and the change was compatible with human DU observation. The cystometry in the DU animal studies is characterized by impaired contractility, prolong intercontraction interval, and hyposensation, while in vitro bladder muscle strips experiment may exhibit normal detrusor contractility. Decreased bladder blood flow and increased oxidative stress in bladders had been proved in different animal DU models, suggesting they should be important in the DU pathogenesis pathway. Sensory receptors mRNA and protein expression changes in DU bladders had been observed in both animal and human studies, including muscarinic receptors M2, M3, adrenergic receptor β3, purinergic receptor P2X1, P2X3, and transient receptor potential vanilloid (TRPV) 1 and TRPV4. Although some of the sensory receptors changes remain controversial, it might be the target for further pharmacologic treatments.