Association of detrusor underactivity with aging and metabolic syndrome: suggestions from animal models.

Detrusor underactivity, a condition in which the bladder muscle does not contract strongly or long enough to empty the bladder completely or within the normal time frame, is a common cause of lower urinary tract symptoms in older individuals of both sexes. Although aging is a known risk factor for detrusor underactivity, its pathophysiological mechanisms are not fully understood. Therefore, establishing animal models that closely mimic the pathophysiology of detrusor underactivity in humans is necessary to elucidate these mechanisms. Metabolic syndrome is a cluster of several risk factors, including obesity, hyperlipidemia, hyperglycemia, and hypertension, which are associated with the development of diabetes, cardiovascular disease, and lower urinary tract dysfunction in both sexes. Notably, bladder dysfunction resulting from detrusor underactivity is observed at an earlier age in animal models with diabetes mellitus than in those without. Recently, detrusor underactivity-like phenotypes have been observed at a relatively early age in animal models with metabolic syndrome, involving obesity, hyperlipidemia, and hypertension, compared with those without. Therefore, this review introduces the association of detrusor underactivity with aging and metabolic syndrome, as well as possible pathophysiological mechanisms for detrusor underactivity from reports of various animal models. Notably, metabolic syndrome may accelerate the onset of age-related detrusor underactivity, and further analysis of old animal models with metabolic syndrome may help elucidate the pathogenesis of detrusor underactivity in humans.

Pirfenidone improves voiding function by suppressing bladder fibrosis in underactive bladder rats.

Underactive bladder (UAB), characterized by a complex set of symptoms with few treatment options, can significantly reduce the quality of life of affected people. UAB is characterized by hyperplasia and fibrosis of the bladder wall as well as decreased bladder compliance. Pirfenidone is a powerful anti-fibrotic agent that inhibits the progression of fibrosis in people with idiopathic pulmonary fibrosis. In the current study, we evaluated the efficacy of pirfenidone in the treatment of bladder fibrosis in a UAB rat model. UAB was induced by crushing damage to nerve bundles in the major pelvic ganglion. Forty-two days after surgery, 1 mL distilled water containing pirfenidone (100, 300, or 500 mg/kg) was orally administered once every 2 days for a total of 10 times for 20 days to the rats in the pirfenidone-treated groups. Crushing damage to the nerve bundles caused voiding dysfunction, resulting in increased bladder weight and the level of fibrous related factors in the bladder, leading to UAB symptoms. Pirfenidone treatment improved urinary function, increased bladder weight and suppressed the expression of fibrosis factors. The results of this experiment suggest that pirfenidone can be used to ameliorate difficult-to-treat urological conditions such as bladder fibrosis. Therefore, pirfenidone treatment can be considered an option to improve voiding function in patient with incurable UAB.

Effect of detrusor underactivity on surgical outcomes of holmium laser enucleation of the prostate.

OBJECTIVE: To evaluate the effect of detrusor underactivity (DUA) on the postoperative outcomes of holmium laser enucleation of the prostate (HoLEP) in patients with benign prostatic hyperplasia (BPH). PATIENTS AND METHODS: Patients with BPH who underwent HoLEP between January 2018 and December 2022 were enrolled in this prospective database study. Patients were divided into DUA (bladder contractility index [BCI] <100) and non-DUA (BCI ≥100) groups. Objective (maximum urinary flow rate [Qmax], post-void residual urine volume [PVR]) and subjective outcomes (International Prostate Symptom Score [IPSS], Overactive Bladder Symptom Score [OABSS], satisfaction with treatment question [STQ], overall response assessment [ORA], and willingness to undergo surgery question [WUSQ]) were compared between the two groups before surgery, and at 3 and 6 months after HoLEP. RESULTS: A total of 689 patients, with a mean (standard deviation [SD]) age of 69.8 (7.1) years, were enrolled. The mean (SD) BCI in the non-DUA (325 [47.2%]) and DUA (364 [52.8%]) groups was 123.4 (21.4) and 78.6 (14.2), respectively. Both objective (Qmax and PVR) and subjective (IPSS, IPSS-quality of life, and OABSS) outcomes after surgery significantly improved in both groups. The Qmax was lower in the DUA than in the non-DUA group postoperatively. At 6 months postoperatively, the total IPSS was higher in the DUA than in the non-DUA group. There were no significant differences in surgical complications between the two groups. Responses to the STQ, ORA, and WUSQ at 6 months postoperatively demonstrated that the patients were satisfied with the surgery (90.5% in the DUA group; 95.2% in the non-DUA group), their symptoms improved with surgery (95.9% in the DUA group; 100.0% in the non-DUA group), and they were willing to undergo surgery again (95.9% in the DUA group; 97.9% in the non-DUA group). There were no significant differences in the responses to the STQ and WUSQ between the two groups. CONCLUSION: Our midterm results demonstrated that patients with BPH and DUA showed minimal differences in clinical outcomes after HoLEP compared to those without DUA. The overall satisfaction was high in the DUA group.

Novel clinical diagnostic criteria based on noninvasive examination findings to predict the presence of urodynamic detrusor underactivity in men.

AIMS: To investigate the usefulness of novel clinical diagnostic criteria based on noninvasive examination findings to diagnose urodynamic detrusor underactivity (DU) in men. METHODS: We developed clinical diagnostic criteria to predict the presence of urodynamic DU in men as follows: (a) bladder voiding efficiency <70% on uroflowmetry, (b) existence of "sawtooth and interrupted waveforms" on uroflowmetry, and (c) ultrasonography-documented intravesical prostatic protrusion <10 mm. We analyzed the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of these clinical criteria for diagnosing urodynamic DU in men aged 50 years or above with lower urinary tract symptoms who underwent urodynamic studies. RESULTS: Of the 314 men analyzed (mean age, 72.4 years; mean detrusor contraction index [DCI], 98.8; and mean bladder outlet obstruction index [BOOI], 43.9), 89 men met this clinical DU diagnostic criteria. Of these, 79 men (88.8%) had urodynamic DU (DCI < 100 and BOOI < 40), nine (10.1%) had DU + BOO (DCI < 100 and BOOI ≥ 40), and one (1.1%) had normal voiding functions. None of the men with urodynamic BOO (DCI ≥ 100 and BOOI ≥ 40) met the clinical DU diagnostic criteria. The sensitivity, specificity, PPV, and NPV of these clinical diagnostic criteria for urodynamic DU were 69.3%, 95.0%, 88.8%, and 84.4%, respectively. CONCLUSION: The proposed clinical DU diagnostic criteria showed a high PPV (88.8%) for diagnosing urodynamic DU. None of the patients with BOO met the clinical diagnostic criteria for DU. These clinical DU diagnostic criteria may be useful in identifying men with urodynamic DU in clinical practice.

How do we make progress in phenotyping patients with LUT such as OAB and underactive detrusor, including using urine markers and microbiome data, in order to personalize therapy? ICI-RS 2023: Part 1.

INTRODUCTION: Overactive bladder (OAB) and Underactive bladder (UAB) could be associated with metabolic syndrome, affective disorders, sex hormone deficiency, changes in urinary microbiota, functional gastrointestinal disorders, or autonomic nervous system dysfunction. OBJECTIVES: The aim of this Think Tank was to provide a guide on how to investigate OAB and/or detrusor underactivity (DU) patients to better clarify the underlying pathophysiology and possibly personalize the treatment. METHODS: A compendium of discussion based on the current evidence related to phenotyping patients with OAB or DU investigating metabolic, neurogical, psychological and gastrointestinal aspects with the aim to personalize the treatment. RESULTS AND CONCLUSIONS: The article emphasizes the critical significance of adopting a comprehensive yet tailored approach to phenotyping patients with lower urinary tract symptoms, such as OAB and UAB. The intricate interplay between the lower urinary tract and various factors, metabolic, neurological, psychological, and gastrointestinal can define unique LUT profiles, enabling personalized therapies to replace the one-size-fits-all approach.

How do we make progress in phenotyping patients with lower urinary tract such as overactive bladder and underactive detrusor, including using urine markers and microbiome data, to personalize therapy? ICI-RS 2023-Part 2.

INTRODUCTION: Overactive bladder (OAB) and underactive bladder (UAB) could be associated with metabolic syndrome, affective disorders, sex hormone deficiency, changes in urinary microbiota, functional gastrointestinal disorders, or autonomic nervous system dysfunction. OBJECTIVES: The aim of this Think Tank was to provide a guide on how to investigate OAB and/or detrusor underactivity (DU) patients to better clarify the underlying pathophysiology and possibly personalize the treatment. METHODS: A compendium of discussion based on the current evidence related to phenotyping patients with OAB or DU using urodynamic tests, functional neuro-imaging, urinary markers, and microbiome. RESULTS AND CONCLUSIONS: The article emphasizes the critical significance of adopting a comprehensive yet tailored approach to phenotyping patients with lower urinary tract (LUT) symptoms, such as OAB and UAB. The intricate interplay between the LUT and various factors, metabolic, neurological, psychological, and gastrointestinal can define unique LUT profiles, enabling personalized therapies to replace the one-size-fits-all approach.

Can we predict whether a man with acute or chronic urinary retention will void after bladder outflow resistance reduction surgery? ICI-RS 2023.

AIMS: To address the predictive factors of a successful voiding after bladder outflow resistance reduction surgery (BORRS) in men presenting with acute or chronic urinary retention (UR). METHODS: A think tank (TT) of ICI-RS was gathered in 2023, Bristol, UK, to discuss several aspects of the problem, such as the pathophysiology of UR, the clinical and urodynamic evaluation of men with UR and whether it is possible to predict which men will be able to successfully void after treatment with contemporary surgical options. RESULTS: The TT agreed that successful voiding after BORRS depends on several factors but that a strong recommendation cannot be made regarding preoperative evaluation and whether there are predictive factors of success because of the heterogeneity of patients and methodology in published trials. The diagnosis of obstruction in men with UR may be challenging when there is apparent reduced detrusor contraction during urodynamic studies. Even in the absence of bladder contractility there is documentation of such cases that have voided adequately after BORRS. Still, detrusor underactivity and inadequate relief of prostatic obstruction are the main causes of an unsuccessful voiding after BORRS. Conventional resection and enucleation methods remain the most successful surgeries in relieving UR in men, whereas the efficacy of minimally invasive surgical treatments needs to be assessed further. CONCLUSION: Research is needed to understand the pathophysiology of UR and the predictors of successful voiding after different types of BORRS in men with UR.

Association between frailty and detrusor overactivity with detrusor underactivity in older women.

PURPOSE: While detrusor overactivity (DO) with detrusor underactivity (DU) (DO-DU) has been described as typical of aging, the pathogenesis of DO-DU is highly multifactorial, and often thought to involve medical conditions beyond the urinary tract. We aimed to explore potential associations between idiopathic DO-DU and frailty in older women after accounting for age. METHODS: The design of the study is a cross-sectional single-center study, in an outpatient urodynamic unit specializing in geriatrics. Participants are consecutive female patients aged ≥65 years without contributory neurological conditions or bladder outlet obstruction who completed a comprehensive geriatric assessment followed by urodynamic evaluation from 2015 to 2019. Participants were categorized as having DO, DU, combined DO-DU, or a negative study. Multinomial logistic regression analysis was used to assess the relationship between urodynamic outcomes and frailty, as quantified using the Frailty index (FI). RESULTS: Ninety-five patients were included (median age 78 [interquartile range: 70-83] years), among whom 29% had combined DO-DU. The median FI score was 0.27 (0.2-0.32) (5-12). A higher FI was associated with significantly greater age-adjusted odds of DO-DU when either DU or subjects with a negative urodynamic assessment were used as the reference group. Age was not significantly associated with DO-DU across all multivariable analyses. CONCLUSION: A higher FI was associated with an increased likelihood of DO-DU, which could not be attributed to the effect of age alone. The pathogenesis of DO-DU is likely more complex than chronological aging in and of itself and merits further study.

Detrusor underactivity after radical prostatectomy: A prospective observational study.

OBJECTIVE: To evaluate the impact of radical prostatectomy (RP) on bladder function with special interest in detrusor underactivity (DU) and to appraise clinical significance of DU in postprostatectomy patients. MATERIAL AND METHODS: This was a prospective, observational study conducted on male patients subjected to laparoscopic RP (LPR). Urodynamic studies were performed at the day before surgery (visit 1), 3-6 months postoperatively (visit 2) and more than 12 months after surgery (visit 3). Incidence of DU that occurred after LPR (de novo DU), incidence of persisting de novo DU after 12 months, clinical relevance of DU after LPR and predictive factors of de novo DU were assessed. RESULTS: 99 of 100 patients underwent preoperative urodynamic study (visit 1) and those were included in further analysis. 84 and 76 patients were available for follow-up at second and third visit respectively. De novo DU occurred after LPR in 25 (29.7%) patients at visit 2 (p < 0.001). Sixteen from 24 patients (66,7%) who developed de novo DU after RP (visit 2) continued to have DU 1 year after surgery (visit 3) (p = 0.04). On the multivariate analysis, urinary incontinence requiring more than 1 pad per day (odds ratio [OR] 5.11; confidence interval [CI] 1.69-17.19; p = 0.005) and preoperative IPSS storage sub-score (OR 1.25; CI 1.03-1.63; p = 0.030) were significantly associated with de novo DU. Postprostatectomy patients with DU had significantly lower Urinary Assessment of the Expanded Prostate Cancer Index Composite (EPIC) total score (819 vs. 911, p = 0.02), EPIC Function domain score (300 vs. 357, p = 0.002) and EPIC Urinary incontinence domain (137 vs. 224, p = 0.002) when compared to their counterparts without DU. CONCLUSIONS: RP substantially influences bladder function, causing de novo DU, which persists in substantial number of patients 1 year postoperatively. Furthermore, significant correlation between DU and postprostatectomy urinary incontinence may play a role when anti-incontinence surgery is considered.

Functional and safety outcomes after benign prostatic enlargement surgeries in men with detrusor underactivity compared with normal detrusor contractility: Systematic review and meta-analysis.

INTRODUCTION: Men with detrusor underactivity (DUA) and concomitant bladder outlet obstruction (BOO) due to benign prostatic enlargement (BPE) may present poorer functional outcomes after surgical desobstruction. This study aimed to evaluate the safety and efficacy of BPE surgery in men with DUA compared with those with normal detrusor contractility (NC). MATERIALS AND METHODS: This review was performed according to the 2020 PRISMA framework. A comprehensive literature search was performed until May 7, 2023, using MEDLINE, EMBASE, and Cochrane Database. No date limits were imposed. Only comparative studies were accepted. The primary endpoint was to assess if there was any difference in short- and long-term functional outcomes after BPE surgery in men with DUA and NC. The secondary endpoint was to evaluate the differences in perioperative outcomes and postoperative complications between the two groups. Meta-analysis was performed using Review Manager (RevMan) software. RESULTS: There were 5 prospective nonrandomized studies and 12 retrospective studies, including 1701 DUA and 1993 NC patients. Regarding surgical procedures, there were eight TURP (transurethral resection of the prostate) studies, four GreenLight PVP (photoselective vaporization of the prostate) studies, two HoLEP (Holmium laser enucleation of the prostate) studies, one GreenLight PVP/HoLEP study, one Holmium laser incision of the prostate study, and one study did not report the type of surgery. We did not find a statistically significant difference between the two groups in terms of perioperative outcomes, including postoperative catheterization time, hospitalization time, urinary retention, need to recatheterization, transfusion rate, or urinary tract infections. Also, we found no significant differences in long-term complications, such as bladder neck stenosis or urethral stenosis. Posttreatment bladder recatheterization and retreatment rate for BPE regrowth could not be evaluated properly, because only one study reported these findings. When we analyzed functional outcomes at 3 months, those with NC had lower International Prostatic Symptom Score (IPSS), lower quality-of-life (QoL) score, better maximum flow rate (Qmax), and lower post-voiding residual (PVR) of urine. These results were maintained at 6 months postoperatively, with exception of PVR that showed no difference. However, at 12 and more than 12 months the functional outcomes became similar regarding IPSS and QoL. There were few data about Qmax and PVR at longer follow-up. CONCLUSION: In this meta-analysis, data suggest that BOO surgical treatment in patients with concomitant BPE and DUA appears to be safe. Despite patients with DUA may present worse functional outcomes in the short postoperative term compared with the NC population, IPSS and QoL scores become comparable again after a longer follow-up period after surgery.

An automatic diagnostic system for the urodynamic study applying in lower urinary tract dysfunction.

OBJECTIVE: To establish an automatic diagnostic system based on machine learning for preliminarily analysis of urodynamic study applying in lower urinary tract dysfunction (LUTD). METHODS: The eight most common conditions of LUTDs were included in the present study. A total of 527 eligible patients with complete data, from the year of 2015 to 2020, were enrolled in this study. In total, two global parameters (patients' age and sex) and 13 urodynamic parameters were considered to be the input for machine learning algorithms. Three machine learning approaches were applied and evaluated in this study, including Decision Tree (DT), Logistic Regression (LR), and Support Vector Machine (SVM). RESULTS: By applying machine learning algorithms into the 8 common LUTDs, the DT models achieved the AUC of 0.63-0.98, the LR models achieved the AUC of 0.73-0.99, and the SVM models achieved the AUC of 0.64-1.00. For mutually exclusive diagnoses of underactive detrusor and acontractile detrusor, we developed a classification model that classifies the patients into either of these two diseases or double-negative class. For this classification method, the DT models achieved the AUC of 0.82-0.85 and the SVM models achieved the AUC of 0.86-0.90. Among all these models, the LR and the SVM models showed better performance. The best model of these diagnostic tasks achieved an average AUC of 0.90 (0.90 ± 0.08). CONCLUSIONS: An automatic diagnostic system was developed using three machine learning models in urodynamic studies. This automated machine learning process could lead to promising assistance and enhancements of diagnosis and provide more useful reference for LUTD treatment.

Underactive Bladder and Detrusor Underactivity: New Advances and Prospectives.

Underactive bladder (UAB) is a prevalent but under-researched lower urinary tract symptom that typically occurs alongside detrusor underactivity (DU). Unlike UAB, DU is a urodynamic diagnosis which the International Continence Society (ICS) defines as "a contraction of reduced strength and/or duration, resulting in prolonged bladder emptying and/or a failure to achieve complete bladder emptying within a normal time span". Despite the widespread prevalence of UAB/DU, there are significant gaps in our understanding of its pathophysiological mechanisms, diagnosis, and treatment compared with overactive bladder (OAB) and detrusor overactivity (DO). These gaps are such that clinicians regard UAB/DU as an incurable condition. In recent years, the understanding of UAB has increased. The definition of UAB has been clarified, and the diagnostic criteria for DU have been considered more comprehensively. Meanwhile, a number of non-invasive diagnostic methods have also been reported. Clinical trials involving novel drugs, electrical stimulation, and stem cell therapy have shown promising results. Therefore, this review summarizes recent reports on UAB and DU and highlights the latest advances in their diagnosis and treatment.

[Urine retention-From the symptom to the structure]. / Harnverhalt ­ vom Symptom zur Struktur.

Urinary retention describes the inability to urinate. Based on the symptoms and the amount of the initial residual urine formation, a differentiation can be made between acute and chronic forms. The cause can be a subvesical obstruction or a bladder atony. In addition to emergency treatment in the form of initial relief of the strain on the bladder by insertion of a catheter, the indication for a definitive treatment with a clarification of the question whether an acute or chronic event is present is also important. Although the selection of the catheter is subject to few criteria, the further structured approach is complex. Both decision trees are presented in this article.

Screening for Zinner Syndrome in Patients With a Congenitally Solitary Kidney: Lessons Learned.

PURPOSE: We determined if serial screening ultrasounds are beneficial in evaluating for the development of Zinner syndrome in males with a congenital solitary kidney. MATERIALS AND METHODS: All patients included had their congenital solitary kidney diagnosed at <20 years of age and had to be ≥20 at their last visit. Individuals were seen annually, with pelvic ultrasounds to screen for mesonephric duct cysts obtained at birth and every year of age, divisible by 5. RESULTS: At a median follow-up of 38 years of age (range 20-57), 17% (20/121) developed Zinner syndrome, with 60% (12/20) developing clinical symptoms. The yield for screening ultrasound studies was significantly higher in patients ≤20 years of age at 3.5% (12/340), compared to 0.33% (1/296) in patients >20 years of age (P = .004). Serial ultrasounds reveal the onset of lower urinary tract and cyst-related pain symptoms are associated with the growth of the seminal vesicle cyst to ≥5 cm (P = .0198). Of symptomatic patients, 75% (8/12) had abnormal uroflows. Complete urodynamic studies revealed findings consistent with bladder outlet obstruction in 38% (3/8), equivocal for obstruction in 24% (2/8), and detrusor underactivity in 38% (3/8). Cyst excision effectively resolved voiding symptoms that were obstructive in etiology but failed to resolve symptoms in patients with detrusor underactivity. CONCLUSIONS: Serial ultrasound evaluations reveal that cyst growth to ≥5 cm in size is highly related to the onset of clinical symptoms, with the resolution of voiding symptoms by cyst excision directly associated with urodynamic findings.

Transcriptomics Reveals Molecular Features of the Bilateral Pelvic Nerve Injury Rat Model of Detrusor Underactivity.

The pathogenesis of detrusor underactivity (DU) is unclear, and the available therapeutic effects are unsatisfactory. We propose to find key molecules and pathways related to DU based on transcriptome sequencing. A rat model of bilateral pelvic nerve injury (BPNI) was established. Bladder tissues from the sham-operated group, 3 and 28 days after BPNI mapping, were taken for urodynamics, histopathology, and RNA-seq. An enrichment analysis of the screened differential expression genes was performed. Three days after BPNI, the results showed urodynamic features of overflow incontinence, while there was a recovery at 28 days after the operation. Masson staining revealed collagen deposition accompanied by progressive thickening of the smooth muscle layer as DU progressed. RNA-seq results suggested that a total of 1808 differentially expressed genes (DEGs) differed among the groups. RNA-seq and subsequent analysis confirmed that the cell cycle and immune response were significantly activated 3 days after BPNI, while extracellular matrix remodeling occurred 28 days after BPNI. Partial DEGs and pathways were verified by qRT-PCR. Validation of key proteins involved in cell cycle, inflammation, and fibrosis was performed by immunohistochemical staining and western blot, respectively. These molecular expression patterns at different time points after BPNI injury provide valuable insights into the search for therapeutic targets for DU.

Is detrusor underactivity associated with voiding dysfunction after single incision sling surgery?

BACKGROUND: Some women experience voiding dysfunction after stress urinary incontinence (SUI) surgery. We explore if detrusor underactivity (DU) found in urodynamic study (UDS) prior to SUI surgery using an adjustable single incision sling (SIS) may be related to voiding dysfunction after surgery. METHODS: This is a prospective, diagnostic, transversal, single center study comparing voiding dysfunction after SUI surgery with a SIS (Altis®; Coloplast, Humlebæk, Denmark) between women with DU (cases) or normal detrusor (controls). Inclusion criterium was women ≥18 years with SUI/mixed UI (stress predominant) operated between June 2013 and December 2020. Exclusion criteria were: women without UDS prior to surgery or without voiding phase in the P/Q, previous incontinence surgery, POP stage ≥2, neurogenic conditions, other pelvic floor surgery. Urinary symptoms were assessed using structured questions evaluating storage/voiding symptoms. Patients were divided into two groups according to projected Isovolumetric Pressure Index (PIP1) with 30-75 cmH2O indicating normal contractility. RESULTS: A total of 139 women were included, 29 (20.9%) in DU group and 110 (79.1%) in control group. Control and DU groups have shown similar objective (75.5% vs. 71.4% P=0.66) and subjective (85.4% vs. 96.1% P=0.22) success rates, respectively, without statistical differences. Voiding symptoms increased after surgery in both groups (+20.7% DU group vs. +8.1% normal group, P=0.29). More voiding symptoms (persistent/de novo) were found in DU group vs. normal group, but without statistically significant differences. CONCLUSIONS: According to our results, the presence of DU previous to SUI surgery with a SIS (Altis®, Coloplast) has no impact on objective and subjective success rates. On the other hand, patients with preoperative DU showed higher proportion of voiding dysfunction but no statistical difference.

Effect of bladder outlet procedures on urodynamic assessments in men with an acontractile or underactive detrusor: A systematic review and meta-analysis.

OBJECTIVE: To review the effect of bladder outlet procedures on urodynamic outcomes and symptom scores in males with detrusor underactivity (DU) or acontractile detrusors (AD). MATERIALS AND METHODS: We performed a systematic review and meta-analysis of research publications derived from PubMed, Embase, Web of Science, and Ovid Medline to identify clinical studies of adult men with non-neurogenic DU or AD who underwent any bladder outlet procedure. Outcomes comprised the detrusor pressure at maximum flow (Pdet Qmax ), maximum flow rate (Qmax ), international prostate symptom score (IPSS), and quality of life (QoL). This study is registered under PROSPERO CRD42020215832. RESULTS: We included 13 studies of bladder outlet procedures, of which 6 reported decreased and 7 reported improved Pdet Qmax after the procedure. Meta-analysis revealed an increase in the pooled mean Pdet Qmax of 5.99 cmH2 0 after surgery (95% CI: 0.59-11.40; p = 0.03; I2 95%). Notably, the Pdet Qmax improved in all subgroups with a preoperative bladder contractility index (BCI) <50 and decreased in all subgroups with a BCI ≥50. All studies reported an improved Qmax after surgery, with a pooled mean difference of 5.87 mL/s (95% CI: 4.25-7.49; I2 93%). Only three studies reported QoL, but pooling suggested significant improvements after surgery (mean, -2.41 points; 95% CI: -2.81 to -2.01; p = 0.007). All seven studies reporting IPSS demonstrated improvement (mean, -12.82; 95% CI: -14.76 to -10.88; p < 0.001). CONCLUSIONS: This review shows that Pdet Qmax and Qmax increases after surgical bladder outlet procedures in men with DU and AD. Bladder outlet procedures should be discussed as part of the shared decision-making process for this group. The evidence was of low to very low certainty.