Lower Urinary Tract Obstruction Research Articles

Nadir creatinine predicts long-term bladder function in boys with posterior urethral valves

Posterior urethral valves (PUV) cause lower urinary tract obstruction leading to increased intravesical pressure during fetal urinary tract development. Though the bladder and kidneys are separate organs, with different embryological origins, they are complementary and influence each other both before and after birth. We aimed to assess the relationship between renal and bladder function in boys with PUV and whether early renal markers could predict future bladder function. We included all boys with prenatally suspected lower urinary tract obstruction, born between 2000 and 2013, in two University Hospitals, with at least 5 years follow-up. We excluded patients who presented a Lower Urinary Tract Obstruction other than PUV, children who presented multiple birth defects and neonatal deaths and those with incomplete long-term renal or bladder function data. We included data on nadir creatinine (NC), long-term renal function and long-term bladder function (defined by Uroflow parameters). Boys with PUV were divided into three severity groups for renal function according to their NC and three severity groups for bladder function as determined by Uroflow. We included 73 boys. Average nadir creatinine was 43.4±26.1μmol/L. Twenty-nine boys (49.3%) presented a NC<35μmol/L, thirty-eight (52.1%) a NC between 35 and 75μmol/L, and 6 (8.2%) a NC>75μmol/L. Thirty-eight (52.1%) presented normal bladder function, 23 (31.5%) presented moderately impaired bladder function and 12 (16.4%) presented severely impaired bladder function. 41.4% of boys with NC<35 had abnormal bladder function vs 46.2% of those with an NC between 35 and 75μmol/L and 83.3% of boys with NC>75μmol/L. Nadir creatinine both predicted both bladder function and renal status (table 1). Correlation between presence of grade 3-5 CKD and poor uroflow was also significant (p<0.005). Nadir creatinine was significantly correlated to bladder function at 5 years of age. What this study suggests is that as nadir creatinine increases so does the risk of severe bladder dysfunction. Our results, though limited to flowmeter and renal function, could help pediatric urologist tailor bladder function monitoring, and indicate which patients could benefit from more aggressive bladder therapy. Bladder and renal function are linked in boys with posterior urethral valves. Boys with high nadir creatinine could benefit from early bladder function evaluation and management.

Development and in-vitro characterization of a novel fetal vesicoamniotic shunt - The Vortex shunt.

To develop and test a novel vesicoamniotic shunt (VAS) to treat fetal lower urinary tract obstruction (LUTO), decrease dislodgement and optimize shunt deployment in-vitro. Vesicoamniotic shunt design objectives included: (1) robust and atraumatic fixation elements, (2) kink resistant conduit to adjust to fetal movement and growth, (3) one-way pressure valve to facilitate bladder cycling, and (4) echogenic deployment visualization aids. The force to dislodge the novel Vortex shunt was compared with existing commercially available shunts in a bench-top porcine bladder model. Sonographic echogenicity was evaluated with ultrasound-guided deployment, and the shunt valve pressure measured. A prototype novel Vortex shunt was developed using braided nitinol "umbrella-type" ends with a kink-resistant stem incorporating an internal one-way valve. The peak force required to dislodge the Vortex shunt was significantly higher than commercially available shunts (p<0.01). Shunt deployment in the bench-top model was easily confirmed with ultrasound guidance and the brisk decompression of the inflated porcine bladder thereafter. In-vitro valve gauge pressure testing mirrored bladder pressures in human LUTO cases. In-vitro testing shows that the Vortex shunt may improve deployment, sonographic visualization, kink resistance, and dynamic size adjustment. Validation in preclinical animal models are warranted and currently underway.

Vesico-amniotic shunt insertion prior to the completion of 16 weeks results in improved preservation of renal function in surviving fetuses with isolated severe lower urinary tract obstruction (LUTO)

The purpose of this retrospective cohort study was to compare the outcome of human fetuses with isolated severe lower urinary tract obstructions (LUTO) that were first treated before the completion of 16 weeks of gestation to fetuses first treated later in gestation. Vesicoamniotic shunt insertion (VAS) was performed in 63 subsequent fetuses with LUTO between 12+5 and 30+3 weeks. The fetuses were analyzed in three groups: Group-I-fetuses underwent their first intervention until the completion of 16 weeks, Group-II-fetuses were first treated between 16+1 and 24+0 weeks and Group-III-fetuses beyond 24+1 weeks. Renal and pulmonary outcome parameters and complicating factors were assessed. - All mothers tolerated the procedures well. Overall fetal survival was 47 of 63 (75%). The mean age at delivery of survivors was 35 weeks. 68% of Group-I-fetuses, 77% of group-II-fetuses, and 100% of group-III-fetuses survived beyond postnatal hospital discharge. Amongst the survivors the chance for normal renal function was higher for group I with 79% (15/19) compared to first fetal intervention after the completion of 16 weeks with 32% (9/28, p=0.003, OR=7.9 [2.0, 30.8] 95% CI). Clinically relevant pulmonary hypoplasia was observed in 11% of Group-I-, 27% of Group-II-, and 20% of Group-III-fetuses. Early intervention in fetal LUTO before the completion of 16 weeks may achieve a higher rate of normal renal and pulmonary function in survivors than treatment beyond that point in time. This observation is important for the future management of this challenging patient population.

Bladder Calculus in a Male Child with Features of Urethral Stricture: Radiologic Findings and a Case Report

Urinary lithiasis is a very common urological disease but bladder lithiasis is very uncommon and account for about 5% of urolithiasis and most frequent urolithiasis in pediatric age. Giant calculi can present with few symptoms, it is very important to exclude lower urinary tract obstruction as the cause, but significant cases may come without obstruction. The male sex is more affected than the female sex. This is a case of an 11 year old male child with complaint of suprapubic pain, dysuria, hematuria, decreased urinary stream and increased frequency of micturition for more than three years prior to presentation. The patient had plain abdominal radiograph showing the region of the kidneys, ureters and urinary bladder (KUB) with an abdominopelvic ultrasonography. These demonstrated a calculus in the urinary bladder measuring about 70mm x 50mm in mediolateral and craniocaudal dimensions. The patient is yet to have a surgical extraction (extraperitoneal cystolithotomy) with of the entire calculus. We present a case of a giant calculus in a child due to its rare nature and peculiar presentation.

Could CA 19-9 be a useful biomarker in the diagnosis, prognosis, and prediction of adequate relief in lower urinary tract obstructions?

posterior urethral valves represent an important cause of childhood chronic kidney disease. The identification of biomarkers that indicate early kidney damage and even adequate clearance could reduce how many patients head towards kidney failure. this study evaluated how this easy-analysis biomarker (CA 19-9) could help identifying potential renal damage and adequate clearance in obstructive uropathies. 46 female Wistar rats were divided into 5 groups, with different patterns of partial urinary tract obstruction: group control; group OIV: infravesical obstruction; group OIVd: infravesical obstruction with reversion, obstruction relief 7 postoperative days later; group OUu: unilateral ureteral obstruction; group OUb: bilateral ureteral obstruction. The CA 19-9s performance was compared to another biomarker: Ngal. Determination of basal CA 19-9 and Ngal in urine and blood and serum creatinine levels was performed in the rats prior to surgery (T0) and after 14 days (T1). Group OIVd underwent intermediate (Ti) collection before clearance. the urinary concentration of CA 19-9 increased in groups OIV, OIVd and OUb; elevation at T1 and Ti, reached statistical significance compared to the T0 value (p<0,05). Changes in urinary CA 19-9 were more expressive in infravesical obstruction groups (AUC 0.81). Obstruction relief in group OIVd promoted significant urinary CA 19-9 reduction (p<0,05) in the final evaluation. CA 19-9 urinary concentration increased in partial urinary tract obstruction. Its best performance was in the bladder neck obstruction group, in which the elevation was detected early (6 days after infravesical obstruction) and the CA19-9 urinary concentration declined after clearance.

Experience with the use of mohan's valvotome for posterior urethral valve ablation at a centre in North-Eastern Nigeria.

Introduction:Posterior urethral valve (PUV) is the most common congenital cause of lower urinary tract obstruction in boys. Management has remained challenging in our region, with features of renal impairment evident in some patients at the time of presentation. Endoscopic valve ablation is the gold standard of treatment, but this is not readily available in our setting. Mohan's valvotome has been described as an alternative device for valve ablation. This study aimed to highlight the clinical presentation, management and early outcomes following valve ablation using Mohan's valvotome.Methods:A retrospective study of boys with PUVs managed between September 2014 and June 2018 was done. The demographic characteristics, clinical features, investigations, treatment and initial outcomes were reviewed. The main outcome measures were improved post-ablation urinary stream, serial serum creatinine values at presentation, 4–5 days of initial catheter drainage and at follow-up.Results:There were ten boys with the median age at presentation of 4 months (mean: 23.9 months; range 10 days to 7 years). Four patients presented after 1 year. All the patients had features of bladder outlet obstruction with associated fever in seven patients and urinary tract infections in six patients. Nine patients (90%) had suprapubic masses, while 2 had ballotable kidneys with co-existing urinary ascites in one patient. Valve ablation was achieved with Mohan's valvotome. There was a significant improvement in the urine stream in all patients. The median duration of follow-up was 7.5 months. Median serum creatinine was 0.95 mg/dl (mean 0.94 mg/d ± 0.38 mg/dl) at follow-up, compared to a median of 4.03 mg/dl at presentation (P = 0.01).Conclusion:Initial drainage and definitive valve ablation with Mohan's valvotome is associated with improved serum creatinine and urinary stream.

Prenatal diagnosis of congenital megalourethra: case report and literature review

Congenital megalourethra is an uncommon cause of lower urinary tract obstruction that is rarely prenatally diagnosed in second trimester sonographic examination as a cystic genital mass. In the presented case, the megalourethra was accompanied with bilateral mild pelviectasis. The newborn had no morbidity during follow-up period. To review the literature, electronic databases including PubMed, Web of Science and Google Scholar were searched up to February 15, 2021. In 51 prenatally diagnosed cases in the literature, most of the cases had accompanying congenital anomalies, especially structural abnormalities in the genitourinary. In the absence of associated abnormalities, the condition of the upper urinary tract is the main determinant of postnatal outcome. The outcome of congenital megalourethra may be good as in our case, but there may also be serious disorders such as renal failure, pulmonary hypoplasia, erectile dysfunction and fertility issues.

Z-scores of fetal bladder size for antenatal differential diagnosis between posterior urethral valves and urethral atresia.

ABSTRACTObjectiveTo construct reference values for fetal urinary bladder distension in pregnancy and use Z‐scores as a diagnostic tool to differentiate posterior urethral valves (PUV) from urethral atresia (UA).MethodsThis was a prospective cross‐sectional study in healthy singleton pregnancies aimed at constructing nomograms of fetal urinary bladder diameter and volume between 15 and 35 weeks' gestation. Z‐scores of longitudinal bladder diameter (LBD) were calculated and validated in a cohort of fetuses with megacystis with ascertained postnatal or postmortem diagnosis, collected from a retrospective, multicenter study. Correlations between anatomopathological findings, based on medical examination of the infant or postmortem examination, and fetal megacystis were established. The accuracy of the Z‐scores was evaluated by receiver‐operating‐characteristics (ROC)‐curve analysis.ResultsNomograms of fetal urinary bladder diameter and volume were produced from three‐dimensional ultrasound volumes in 225 pregnant women between 15 and 35 weeks of gestation. A total of 1238 urinary bladder measurements were obtained. Z‐scores, derived from the fetal nomograms, were calculated in 106 cases with suspected lower urinary tract obstruction (LUTO), including 76 (72%) cases with PUV, 22 (21%) cases with UA, four (4%) cases with urethral stenosis and four (4%) cases with megacystis‐microcolon‐intestinal hypoperistalsis syndrome. Fetuses with PUV showed a significantly lower LBD Z‐score compared to those with UA (3.95 vs 8.83, P < 0.01). On ROC‐curve analysis, we identified 5.2 as the optimal Z‐score cut‐off to differentiate fetuses with PUV from the rest of the study population (area under the curve, 0.84 (95% CI, 0.748–0.936); P < 0.01; sensitivity, 74%; specificity, 86%).Conclusions Z‐scores of LBD can distinguish reliably fetuses with LUTO caused by PUV from those with other subtypes of LUTO, with an optimal cut‐off of 5.2. This information should be useful for prenatal counseling and management of LUTO. © 2021 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.

Impact of surgical intervention on progression to end-stage renal disease in patients with posterior urethral valve

BackgroundPosterior urethral valve patients present with varied presentations at any age of life and have significant associated morbidity and require long-term follow-up and care.MethodsThis was a single-center ambispective cohort study carried out over a period of 2 years. Patient data regarding the symptoms, investigations, interventions, secondary complications were recorded and were followed up regularly during the study till either normalization of their creatinine level which was maintained up to one-year post-fulguration (non-CKD) or progression to end-stage renal disease (ESRD) requiring renal transplant. Various clinical factors were then compared between these groups.ResultsThe age of presentation varies from 6 months antenatal period to a maximum of 34 years. Most common symptom was of lower urinary tract obstruction, followed by recurrent febrile UTI. The interval between disease presentation detection and PU valve fulguration ranged from 6 days to more than 5 years, median duration being 1 month. 85.7% patients had hydroureteronephrosis on initial USG. In VCUG, there was no significant difference found between the presence of reflux and poor renal outcome. Age of presentation greater than 2 years was seen in 52% of patients with CKD compared to only 10% patients in non-CKD group (significant, p value 0.02). Among patients who developed CKD, 60% of patients had PU valve fulguration after one month of disease presentation, while in contrast, among the non-CKD group, 80% of patients had it done within one month of disease presentation. (significant, p value 0.03).ConclusionsLate age of presentation, delayed fulguration with high initial creatinine, and failure of serum creatinine to return to normal after one-month post-fulguration are important risk factors in the progression of the disease to ESRD. Symptomatic improvement after interventions does not correlate with progression to ESRD. The number of interventions also does not predict progression to ESRD. Interventions should be chosen wisely on case to restore near-normal physiology and delay progression to ESRD.

Участие Р2-рецепторов в сократительной активности мочевого пузыря пациентов с доброкачественной гиперплазией предстательной железы

AIM to study the role of P2 receptors in impaired bladder contractility in patients with lower urinary tract obstruction. MATERIALS AND METHODS in pharmacological studies, tissue samples from the bladder wall of 30 patients were used, obtained during planned surgical interventions for benign prostatic hyperplasia (transvesical simple prostatectomy without placement of cystostomy tube). Based on these tissue, isolated smooth muscle specimens were prepared. Their mechanical activity and the efficiency of ligands of purine P2 and other receptors were evaluated. With this aim, the following P2-receptor agonists were used: adenosine triphosphoric acid (ATP), adenosine diphosphoric acid (ADP), uridine-5'-triphosphoric acid (UTP), alpha, beta-methylene-ATP, 2-methylthio-ADP, as well as antagonists of P2-disulfonate receptors acid (PPADS), suramin, NF023, MRS2500. In addition, the efficiency of ligands of other receptors, including carbacholine, epinephrine, histamine, serotonin, atropine was evaluated. RESULTS the most effective agonist was alpha-beta-methylene-ATP, while ATP and 2-methylthio-ADP were significantly less active. In our experiments, ADP and UTP did not show an effect on human bladder. The influence of P2 receptor agonists was inhibited by P2 receptor antagonists PPADS and suramin, as well as MRS2500, although to a lesser extent. Carbacholine caused a strong concentration-dependent contractile response of the bladder, which was inhibited by atropine. Histamine resulted in mild bladder contractions only at high concentrations. Epinephrine and serotonin did not cause significant changes in the contractile activity of the bladder. CONCLUSION The main subtype of P2 receptors involved in the contractile activity of the human bladder is P2X1 receptors. P2Y1 receptors also have some influence on the contraction, while other subtypes of P2 receptors are not detected by pharmacological methods.

Fetal therapy of LUTO (lower urinary tract obstruction) – a follow-up observational study

Purpose Fetal megacystis (MC) can be severe and is mainly caused by fetal lower urinary tract obstruction (LUTO). Mortality of fetal LUTO can be high as a result of pulmonary hypoplasia and/or (chronic) renal insufficiency. Several technical procedures for vesicoamniotic shunting (VAS) were developed to improve fetal MC outcomes. Material and methods We present the outcome of nine fetuses with MC who received VAS in the prenatal period (14 + 6 to 27 + 6 weeks GA) using the Somatex® intrauterine shunt system. MC was defined as an increased longitudinal measurement of the bladder >15 mm. The median follow-up time after birth was 18 months. Results Eight Fetuses had uncomplicated VAS intervention. One case developed PPROM 24 h after VAS leading to abortion. Pregnancy was later terminated in further two cases. All six live-born infants received intensive care treatment. Invasive-mechanical ventilation was necessary in one case who died 24 h post-partum of severe cardiac depression. Five infants who survived the follow-up time developed chronic renal insufficiency (CRI), with one infant developing end-stage renal failure requiring peritoneal dialysis. Conclusion Overall, 5 of 9 LUTO fetuses (55%) undergoing VAS with the Somatex® intrauterine shunt system showed long-term survival beyond the neonatal period of 28 d (5/9; 55%) with varying morbidity.

Genome-Wide Survey for Microdeletions or -Duplications in 155 Patients with Lower Urinary Tract Obstructions (LUTO).

Lower urinary tract obstruction (LUTO) is, in most cases, caused by anatomical blockage of the bladder outlet. The most common form are posterior urethral valves (PUVs), a male-limited phenotype. Here, we surveyed the genome of 155 LUTO patients to identify disease-causing CNVs. Raw intensity data were collected for CNVs detected in LUTO patients and 4.392 healthy controls using CNVPartition, QuantiSNP and PennCNV. Overlapping CNVs between patients and controls were discarded. Additional filtering implicated CNV frequency in the database of genomic variants, gene content and final visual inspection detecting 37 ultra-rare CNVs. After, prioritization qPCR analysis confirmed 3 microduplications, all detected in PUV patients. One microduplication (5q23.2) occurred de novo in the two remaining microduplications found on chromosome 1p36.21 and 10q23.31. Parental DNA was not available for segregation analysis. All three duplications comprised 11 coding genes: four human specific lncRNA and one microRNA. Three coding genes (FBLIM1, SLC16A12, SNCAIP) and the microRNA MIR107 have previously been shown to be expressed in the developing urinary tract of mouse embryos. We propose that duplications, rare or de novo, contribute to PUV formation, a male-limited phenotype.

Bladder outlet obstruction

Bladder outlet obstruction

Hydroureter

Hydroureter

Obstetric outcomes after fetal intervention – a single-center descriptive review

Background Advancements in fetal interventions have enabled in utero management of several fetal congenital anomalies and conditions; these are accomplished via ultrasound-guided, fetoscopic or open techniques. Understanding the risk of preterm labor associated with each technique is critical for patient counseling and choice of intervention; however, data on obstetrical outcomes associated with each type of intervention remains limited. Objective To provide descriptive information on the risk of preterm birth following fetal intervention, based on underlying disease and procedure performed. Study design This is a retrospective cohort study of patients who underwent fetal intervention at our institution between 1 October 2016 and 31 December 2019. Interventions were stratified into three groups- ultrasound-guided, fetoscopic and open procedures. Procedures included fetoscopic laser ablation (FLA) for twin-to-twin transfusion syndrome (TTTS), fetoscopic endotracheal occlusion (FETO) for congenital diaphragmatic hernia (CDH), vesicoamniotic shunt (VAS) for lower urinary tract obstruction (LUTO), fetal cystoscopy for LUTO, and open and fetoscopic myelomeningocele repair. The primary outcomes were gestational age at delivery and frequency of premature rupture of the membranes. Results Sixty-eight patients were included; 20 (29.4%) underwent ultrasound- guided procedures, 37 (54.4%) underwent fetoscopy, and 11 (16.2%) open in utero intervention. The diagnoses and type of intervention within each group were different. The mean gestational age (GA) ± standard deviation (SD) at intervention for ultrasound- guided, fetoscopic, open procedures were 24.1 ± 4.4 weeks, 22.8 ± 3.7 weeks, and 25.0 ± 0.9 weeks, respectively. The mean GA ± SD at delivery were 31.9 ± 4.9 weeks, 31.6 ± 4.6 weeks, and 32.6 ± 5.5 weeks, respectively. The mean interval from time of intervention to delivery were 54 ± 39, 62 ± 37 and 55 ± 36 days, respectively (p = 0.82); and the risk of PPROM was 26.3%, 21.6% and 27.3%, respectively. The mean GA at delivery and the frequency of PPROM were different for each specific disease that was treated. Conclusion The risk of preterm birth and PPROM following fetal intervention with different procedures, categorized under ultrasound- guided, fetoscopic and open fetal interventions at our institution were similar amongst the three groups, but they were different depending on the diagnosis of the treated anomaly.

Комплексный подход к лечению стриктур уретры, вызванных склероатрофическим лихеном

Aim to evaluate the correctness of the diagnosis of lichen sclerosus with an evaluation of complications in the form of urethral strictures and to ensure long-term monitoring of patient management in order to avoid recurrence of fibrous complications and ascending infection in case of lower urinary tract obstruction. Material and methods a total of 55 men aged from 17 to 85 years with lichen sclerosus complicated by urethral stricture who were treated from 2005 to 2020 were included in the study. All patients underwent a comprehensive urological examination. From them, 18 (32.7%) patients had previously undergone various types of urethral procedures and were admitted with recurrent urethral stricture for repeated surgery. Results an examination of patients with lichen sclerosus complicated by urethral strictures is presented, including a morphological assessment of the resected tissue and analysis of etiopathogenetic factors. In addition, the results of complex treatment of patients with urethral strictures associated with sclerosus were evaluated. An increase in the maximum urine flow rate and a decrease in post-void residual volume by almost three times was noted 1-3 months after urethroplasty. After 6 months, a recovery of an adequate micturition and complete absence of residual urine were revealed. The morphological picture in patients with urethral strictures associated with lichen sclerosus is characterized by focal atrophy of the epidermis, replacement of the columnar epithelium with a stratified epithelium with signs of hyperkeratosis and acanthosis, histiolymphocytic infiltration, and the formation of microcalcifications under the basement membrane. Conclusion the correctness of the diagnosis verification and the choice of the treatment strategy in patients with urethral strictures caused by lichen sclerosus significantly contributes to the favorable outcomes. Based on comparative analysis, we can conclude than complex approach to the treatment of patients with urethral strictures associated with lichen sclerosus is highly effective.

Two Cases of Fetal Lower Urinary Tract Obstruction (LUTO) with Similar Presentations Before But Contrasting Outcomes After Fetoscopic Laser Fulguration of Posterior Urethral Valves

Two Cases of Fetal Lower Urinary Tract Obstruction (LUTO) with Similar Presentations Before But Contrasting Outcomes After Fetoscopic Laser Fulguration of Posterior Urethral Valves

Outcome of PUV Patients Following Ablation in a Tertiary Teaching Hospital in Addis Ababa, Ethiopia.

BackgroundPosterior urethral valve (PUV) is the most common cause of congenital lower urinary tract obstruction in boys. It is considered that early diagnosis and intervention have good outcomes in terms of renal function, though the varying extent of embryological insult requires these boys to remain in extended follow-up and care.ObjectiveTo assess the renal outcome of patients following PUV ablation.MethodsThis was a descriptive retrospective study. Data were collected from the operation logbooks of patients from 2015 to 2019 that had been admitted to the Tikur Anbessa Specialized Hospital pediatric surgery unit with a working diagnosis of PUV and had ablation done primarily or following diversion. Data were collected from January to April 2020 and analyzed using SPSS 25. P value≤0.05 was considered significant.ResultsSeventy patients were analyzed and followed for 3 years for the development of postoperative chronic kidney disease (CKD) after PUV ablation. Postoperative CKD was found in 52.9% of patients and end-stage renal disease in 2.9%. Risk factors associated with postoperative CKD were the presence of preoperative and postoperative proteinuria, postoperative hypertension, and elevated nadir serum creatinine. Results also showed that a delay between the development of vesicostomy and ablation had a significant correlation with renal outcome. Elevated nadir serum creatinine, postoperative proteinuria, and delay between the development of vesicostomy and ablation were found to be independent risk factors of development of CKD.ConclusionThere was a high rate of CKD development in patients who had had ablation for PUV, which was comparable to other studies. Three variables were found to be independent risk factors for the progression of CKD, unlike other findings seen in low- and middle-income countries.

Diagnostics of anatomical obstruction of the lower urinary tract using uroflowmetry with a pharmacourodynamic test

Uroflowmetry is an effective, non-invasive method for detecting lower urinary tract obstruction. However, by the nature of the uroflowgram, it is impossible to distinguish between the anatomical and functional obstruction of the urethra. The aim of the study was to develop a screening non-invasive method for the diagnosis of anatomical urethral obstruction using uroflowmetry with a pharmacourodynamic test with selective alpha-1-blocker silodosin. The study involved 235 patients aged 66.2±1.8 years (from 30 to 76 years) with symptoms of the lower urinary tract (LUTS). Uroflowmetry was performed using a “Flow-K” uroflowmeter. Ultrasound examinations of the kidneys, prostate and bladder with determination of residual urine were performed using a HONDA HS-2000 ultrasound machine. All patients underwent a pharmacourodynamic test: repeated uroflowmetry 2.5-3 hours after a single dose of 8 mg of silodosin, taking into account the pharmacodynamics of the drug. During the pharmacourodynamic test, 15 patients with obstructive or obstructive-interrupted uroflowgram had no reaction to silodosin, which was considered a positive test for anatomical (mechanical) urethral obstruction. Аn increase the maximum and average volumetric flow rate of urine during urination by 25-30%, respectively from 9.02±0.24 ml/s up to 11.69±0.32 ml/s and from 5.64±0.21 ml/s to 7.03±0.25 ml/s, were noted in 220 patients with obstructive, obstructive-interrupted obstructive-intermittent or intermittent type of uroflowgram when conducting a pharmacaurodynamic test. Such results were considered negative for anatomical (mechanical) urethral obstruction. They testified to functional obstruction of the urethra, which was subsequently successfully corrected with prescribing selective alpha-1-blockers. Patients with a positive pharmacourodynamic test were prescribed further examination using such methods as ureteroscopy, urethrocystoscopy, retrograde urethrography, to confirm the violation of the patency of the urethra or bladder neck. Urethral stricture was diagnosed in 10 patients, a calculus of the posterior urethra in 2 patients, a median lobe of the prostate gland in 3 patients with BPH. In the presence of obstructive or obstructive-interrupted uroflowgram in patients with LUTS, the pharmacourodynamic test with silodosin can be used as a screening non-invasive test to detect anatomical obstruction of the lower urinary tract.

Predictive accuracy of prenatal ultrasound findings for lower urinary tract obstruction: A systematic review and Bayesian meta-analysis.

Lower urinary tract obstruction (LUTO) is a rare but critical fetal diagnosis. Different ultrasound markers have been reported with varying sensitivity and specificity. The objective of this systematic review and meta-analysis was to identify the diagnostic accuracy of ultrasound markers for LUTO. We performed a systematic literature review of studies reporting on fetuses with hydronephrosis or a prenatally suspected and/or postnatally confirmed diagnosis of LUTO. Bayesian bivariate random effects meta-analytic models were fitted, and we calculated posterior means and 95% credible intervals for the pooled diagnostic odds ratio (DOR). A total of 36,189 studies were identified; 636 studies were available for full text review and a total of 42 studies were included in the Bayesian meta-analysis. Among the ultrasound signs assessed, megacystis (DOR 49.15, [15.28, 177.44]), bilateral hydroureteronephrosis (DOR 41.33, [13.36,164.83]), bladder thickening (DOR 13.73, [1.23, 115.20]), bilateral hydronephrosis (DOR 8.36 [3.17, 21.91]), male sex (DOR 8.08 [3.05, 22.82]), oligo- or anhydramnios (DOR 7.75 [4.23, 14.46]), and urinoma (DOR 7.47 [1.14, 33.18]) were found to be predictive of LUTO (Table 1). The predictive sensitivities and specificities however are low and wide study heterogeneity existed. Classically, LUTO is suspected in the presence of prenatally detected megacystis with a dilated posterior urethra (i.e., the keyhole sign), and bilateral hydroureteronephrosis. However, keyhole sign has been found to have modest diagnostic performance in predicting the presence of LUTO in the literature which we confirmed in our analysis. The surprisingly low specificity may be influenced by several factors, including the degree of obstruction, and the diligence of the sonographer at searching for and documenting it during the scan. As a result, providers should consider this when establishing the differential for a fetus with hydronephrosis as the presence or absence of keyhole sign does not reliably rule in or rule out LUTO. Megacystis, bilateral hydroureteronephrosis and bladder wall thickening are the most accurate predictors of LUTO. Given the significant consequences of a missed LUTO diagnosis, clinicians providing counselling for prenatal hydronephrosis should maintain a low threshold for considering LUTO as part of the differential diagnosis.