[Post-obstructive polyuria. Pathophysiological analysis of a case]. / Poliuria post-obstructiva. Análisis fisiopatológico de un caso.

The relief of the impediment to urinary flow is the treatment of acute kidney failure due to urinary tract obstruction. However, there is a risk of inducing massive polyuria, which can be self-limited or produce severe contraction of the intravascular volume with pre-renal acute kidney failure and alterations in the internal environment. Polyuria, urine output > 3 L/d or > 200 mL/min for more than 2 hours, can have multiple causes, and can be classified as osmotic, aqueous or mixed. Post-obstructive polyuria obeys different pathogenic mechanisms, which overlap and vary during a patient's evolution. Initially, there is a decrease in vasoconstrictor factors and an increase in renal blood flow, which, added to the excess of urea accumulated, will cause intense osmotic diuresis (osmotic polyuria due to urea). Added to these factors are the positive sodium and water balance during acute renal failure, plus the contributions of crystalloid solutions to replace diuresis (ionic osmotic polyuria). Finally, there may be tubular dysfunction and decreased solutes in the renal medullary interstitium, adding resistance to the action of vasopressin. The latter causes a loss of free water (mixed polyuria). We present the case of a patient with post-obstructive polyuria where, by analyzing the clinical symptoms and laboratory alterations, it was possible to interpret the mechanisms of polyuria and administer appropriate treatment for the pathogenic mechanism.

Effect of Early Oxybutynin Treatment on Posterior Urethral Valve Outcomes in Infants: A Randomized Controlled Trial.

PURPOSE: We studied the effect of oxybutynin on bladder and upper urinary tract outcomes in infants following posterior urethral valve ablation. MATERIALS AND METHODS: Patients younger than 12 months old who had undergone primary endoscopic valve ablation for posterior urethral valves were screened for eligibility. Patients who had undergone urinary diversion or had other conditions that could affect lower urinary tract function were excluded. Study patients were randomized to either oxybutynin (0.2 mg/kg 3 times daily) until toilet training or active observation. The study end points were serum creatinine, estimated glomerular filtration rate, hydronephrosis improvement, vesicoureteral reflux resolution, febrile urinary tract infection and toilet training. RESULTS: A total of 49 infants (24 receiving oxybutynin and 25 undergoing observation) were enrolled between December 2013 and September 2015 and completed at least 1 year of followup. Oxybutynin was discontinued before toilet training in 5 patients due to facial flushing in 2, bladder and upper tract dilatation in 2, and cognitive changes in 1. After a median followup of 44.2 months (range 12 to 57.6) median serum creatinine and estimated glomerular filtration rate were not significantly different between the groups (p=0.823 and p=0.722, respectively). Renal units in the oxybutynin group had a greater likelihood of hydronephrosis improvement (61.9% vs 34.8%, p=0.011) and resolution of vesicoureteral reflux (62.5% vs 25%, p=0.023). Febrile urinary tract infection (29.2% vs 40%, p=0.404), completion of toilet training (70.8% vs 76%, p=0.748) and age at toilet training (p=0.247) did not differ significantly between the oxybutynin and observation groups. CONCLUSIONS: Oxybutynin enhances hydronephrosis improvement and vesicoureteral reflux resolution following primary endoscopic valve ablation in infants but periodic monitoring is warranted.

Interactive Effects of Perinatal BPA or DES and Adult Testosterone and Estradiol Exposure on Adult Urethral Obstruction and Bladder, Kidney, and Prostate Pathology in Male Mice.

Obstructive voiding disorder (OVD) occurs during aging in men and is often, but not always, associated with increased prostate size, due to benign prostatic hyperplasia (BPH), prostatitis, or prostate cancer. Estrogens are known to impact the development of both OVD and prostate diseases, either during early urogenital tract development in fetal-neonatal life or later in adulthood. To examine the potential interaction between developmental and adult estrogen exposure on the adult urogenital tract, male CD-1 mice were perinatally exposed to bisphenol A (BPA), diethylstilbestrol (DES) as a positive control, or vehicle negative control, and in adulthood were treated for 4 months with Silastic capsules containing testosterone and estradiol (T+E2) or empty capsules. Animals exposed to BPA or DES during perinatal development were more likely than negative controls to have urine flow/kidney problems and enlarged bladders, as well as enlarged prostates. OVD in adult T+E2-treated perinatal BPA and DES animals was associated with dorsal prostate hyperplasia and prostatitis. The results demonstrate a relationship between elevated exogenous estrogen levels during urogenital system development and elevated estradiol in adulthood and OVD in male mice. These findings support the two-hit hypothesis for the development of OVD and prostate diseases.

Account for high flow rate-low detrusor pressure voids in female: Contribution of VBN model.

INTRODUCTION: Nomograms using the VBN model of women micturition allowed evaluating detrusor contractility (k) and urethral obstruction (U) from pressure-flow (PFs) recordings. While the model worked for most of the patients, an intriguing result, negative U value was observed for patients with high flow-low detrusor pressure (Qp voids). To explain that condition, our hypothesis was a weak urethral resistance to dilatation or increased expansibility (URD). METHODS: The area offered to the fluid at each point of the urethra (its dilatation) is a function of the time depending difference between inside and outside pressures. In the VBN model, this function is sigmoid-like, the same for all women. For Qp voids, Qrecorded was more higher than it would be with the recorded pressure (VBN analysis). So, modeling allowed computing abnormally increased urethral wall expansibility (URD) whose consequence would be an increased flow. RESULTS: Among 222 non-neurologic women referred for investigation of various lower urinary tract symptoms, 27 (mean age 66.3±11.4 y) had Qp void: Qmax=27±6mL/s; pdet.Qmax =7.5±4.7cm H2O. Mean URD value was .36±.67. Introduction of URD in a modeled analysis of urodynamic traces led to a good fitting between recorded and computed traces for the 27 Qp. CONCLUSION: Mathematical modeling of micturition allows proposing an explanation of the unexpected observations of Qp voids. They would be due to abnormal urethral wall elasticity. Despite major challenges measurement of this elasticity would be the next step. LEVEL OF EVIDENCE: 3.

Myocardial function in fetuses with lower urinary tract obstruction: Is there a cardiac remodeling effect due to renal damage?

OBJECTIVES: Cardiac remodeling due to renal dysfunction may have an impact on myocardial function (MF) of fetuses with lower urinary tract obstruction (LUTO). The aim was to identify possible differences in MF in LUTO fetuses compared with healthy controls and to look for interactions between urine biochemistry and MF indices. METHODS: This is a cohort study consisting of 31 LUTO fetuses and 45 healthy controls. Subgroups were generated according to intrauterine therapy (group 1: LUTO after therapy, group 2: LUTO without therapy at the time of examination, and group 3: controls). MF indices were measured using pulsed wave tissue Doppler imaging and M-mode. Furthermore, results of fetal urine biochemistry were gathered retrospectively. RESULTS: Among other findings, right ventricular (RV) e'/a' ratio was lower in group 1 compared with group 3 (p = .050). According to gestational age (GA) level-dependent analysis, RV isovolumetric relaxation time was significantly longer in group 2 compared with group 1 and group 3 at GA level 1 (19 wk of gestation). A significant positive correlation between RV e'/a' ratio and ß-2-microglobulin as well as α-1-microglobulin and potassium could be observed. CONCLUSION: We observed differences in MF and an association between ventricular filling pattern and renal protein secretion in LUTO fetuses. This can be interpreted as a sign of intrauterine cardiac remodeling.

Are nomograms based on free uroflows helpful to evaluate urethral obstruction in men?

AIMS: It was demonstrated earlier that reduced maximum flow-rate (Qmax ) during intubated flow (IF) in women may be the consequence of a urethral reflex. Over-estimation of outflow obstruction is the consequence. Our hypothesis, that a similar phenomenon could occur in men, is tested using results of a free uroflow (FF) preceding an IF to eventually correct the Abrams-Griffiths (AG) number. METHODS: Retrospectively, analysis of 441 urodynamic studies of men suspected of bladder outflow obstruction (BOO) was performed. The Valentini-Besson-Nelson model links outflow obstruction (parameter pucp) and the detrusor contractility (parameter k) to Qmax and detrusor pressure at Qmax (pdet.Qmax ). AG and pucp are strongly correlated. Contractility is described by a graphical representation (a nomogram) which numerical fitting is an algebraic equation f(Qmax ,pdet.Qmax ). Nomograms based on IF allowed computing a calculated AG (corr-AG) on the basis of free flow. RESULTS: Included files (N = 362) had filling volume during FF > 90 mL; corr-AG was compared to AG. When Qmax.FF > 1.5*Qmax.IF (N = 114), 61 patients (53.5%) were found less obstructed with corr-AG, no one more obstructed. Increased BOO could be the result of a urethral reflex during IF and AG gave an overestimation. When Qmax.FF < 1.5*Qmax.IF (N = 248), only 39 patients (12.1%) were found less obstructed with corr-AG and 28 (11.3%) more obstructed. CONCLUSION: To obtain a reliable evaluation of BOO in men, it is suitable to perform a FF before IF. A corrected AG (corr-AG) obtained from IF analysis and nomograms based on FF may be helpful for evaluation of BOO in men.

Current strategies to predict and manage sequelae of posterior urethral valves in children.

Posterior urethral valves (PUV) constitute a significant urological cause of chronic kidney disease (CKD) in children. The condition is characterised by the unique pathophysiology of the evolution of bladder dysfunction after relief of obstruction, which contributes to CKD. Improvements in prenatal diagnosis followed by selective foetal intervention have not yet produced improvement in long-term renal outcomes, although better patient selection may alter this in the future. Proactive management with surveillance, pharmacotherapy, timed voiding, double voiding, and/or assisted bladder-emptying, is being increasingly offered to those with severe bladder dysfunction and has the potential of reducing the burden of renal disease. Clinicians are currently able to counsel regarding the prognosis using serum creatinine and other emerging markers. However, much of this work remains to be validated. Satisfactory graft survival rates are now reported with aggressive management of bladder dysfunction in children who are candidates for renal transplantation. Knowledge gaps exist in identifying early markers of renal injury, risk stratification, and in understanding patient and carer perspectives in PUV.

Long-term renal outcome in infants with congenital lower urinary tract obstruction.

INTRODUCTION: Congenital Lower Urinary Tract Obstructions (LUTO) is a heterogeneous group of diseases in which urine elimination is obstructed at the level of bladder neck or urethra. The aim of the study is to evaluate the long-term renal outcome of patients suffering of congenital LUTO. PATIENTS AND METHOD: We retrospectively reviewed patients with congenital LUTO. All patients had at least 1 year follow-up. Data on surgery, renal imaging and Schwartz estimate creatinine clearance were collected. Incidence of Chronic Renal Disease (CRD) is presented with Kaplan-Meier method. RESULTS: 40 patients were included, 23 patients with Posterior Urethral Valve (PUVs) and 17 patients with other aetiologies: anterior urethral valve (2), urethral atresia (2), urethral stenosis (2), cloacal malformations (2), obstructive ureterocele (1), bladder trigone malformation (1) and neonatal bladder-sphincter dysfunction without neurological abnormalities (7). Incidence of CRD at age 10 years was 37% in congenital LUTO, 42% in PUVs and 30% in other aetiologies, and was significantly higher in PUVs (P=0.032). Renal prognosis was significantly worsened by discover of retentional bladder wall changes in initial cystoscopy, and by loss of parenchymal differentiation or cortical microcysts in first ultrasonography. The use of urinary diversion was significantly higher in LUTO of other aetiologies. CONCLUSION: A high incidence of CRD is observed in patients with congenital LUTO, significantly higher in patients with PUV. LUTO of other aetiologies require step by step surgical management and higher use of urinary diversion. Precise initial evaluation in cystoscopy and ultrasonography is required and participate to evaluate future renal outcome. LEVEL OF INCIDENCE: 4.

[Consequences of prostatic obstruction on bladder function, impact of removal, and management of recurrence after surgery]. / Conséquences de l'obstruction prostatique sur le fonctionnement vésical, impact de la désobstruction, et prise en charge des récidives après chirurgie.

OBJECTIVE: Our objective was to evaluate bladder outlet obstruction (BOO) consequences on the detrusor activity, to analyze the impact of medical and surgical treatments, and to study the reasons for recurrence of urinary symptoms after surgical treatment. METHOD: A non-systematic review of the scientific literature was conducted from the PubMed database to retrieve the most relevant scientific publications between 2000 and July 2018 with the keywords: BPH, bladder obstruction, bladder instability, surgery, and reoperation. A first research was crossed with the results of the reviews of literature already published and was enriched by the contributions of the various authors. A synthesis has been proposed. RESULTS: The consequences of bladder outlet obstruction (BOO) on the detrusor may be detrusor overactivity (DOA) or detrusor hypocontractility. DOA is found in about 50% of patients at the time of their surgery and its evolution is most often favorable after surgical treatment (resolved or reduced in 2/3 of cases). Bladder hypocontractility is responsible for acute or chronic urinary retention. It can be the cause for poor postoperative micturition recovery requiring self-catheterization which the patient must have been informed before surgical treatment. Surgery reduces urinary symptoms with a low but significant surgical revision rate (10 to 30% depending on the surgical technique). The less efficient technique with regard to surgical revision rates are prostatic radiofrequency or cervico-prostatic incision, followed by laser vaporization techniques, TURP and adenomectomy (surgical or endoscopic). Adenomectomy is the surgical technique that has the lowest recurrence rate. The identified risk factors for surgical revision are the surgeon's experience, the power of the laser (in case of photovaporization), the surgical technique employed, the length of operative time, the low or excessive volume of the prostate, the significant pre-operative post-void residual volume, and the slight decrease of postoperative PSA level. Prior to any surgical revision for recurrence of urinary symptoms, the assessment should include the review of previous surgical report, the evaluation of the resected prostatic volume and the residual prostatic volume, the IPSS score, the calendar of micturition, the urethrocystoscopy and the urodynamic assessment. CONCLUSION: BOO can lead to bladder dysfunction such as DOA or detrusor hypocontractility. Resolution of BOO by a suitable surgical treatment allows, in the majority of the cases, to resolve bladder dysfunctioning. In case of failure, the assessment must be complete to define the causes and to find the most suitable solution.

VBN-based nomograms provide critical voiding parameters which can be used for invasive or non-invasive flow interpretation of women at risk of obstruction over time.

AIMS: To design a simple office-based method to evaluate characteristic parameters from free uroflowmetries (FF) or pressure flow studies (PFs). This method can be applied by any physician to any recording, for instance in the follow-up of women at risk of developing outflow obstruction over time after surgical interventions. METHOD: Using pressure-flow studies (PFs), a reliable evaluation of urethral obstruction (U) and detrusor contractility (k) parameters could be obtained from the maximum flow rate and detrusor pressure at maximum flow rate. Nomograms for these parameters were derived from theoretical computations using the VBN model. Then, to allow an evaluation of the real urethral obstruction, a protocol was designed incorporating FF data in the follow-up of women suspected of urethral obstruction. RESULTS: Two nomograms were obtained: (1) A urethral obstruction nomogram allowing to define a Woman Obstruction Index (WOI = pdet.Qmax - 0.5*Qmax ) which has the same structure than the A-G number in men. (2) A detrusor contractility nomogram which was generalized to all initial bladder volumes. The curves were fitted by algebraic equations easily programmable on any handheld device. CONCLUSION: Using a mathematical model of micturition and data extracted from PFs, two nomograms on urethral obstruction and detrusor contractility were designed. This tool offers a rapid and practical method for the clinician to follow women at risk of obstruction over time. Its applications will be the purpose of further studies. Neurourol. Urodynam. 36:37-42, 2017. © 2015 Wiley Periodicals, Inc.

Effect of Doxazosin on Autonomic Nervous Control and Urodynamics of Rat Urinary Bladder during Modeled Infravesical Obstruction.

The therapeutic effect of doxazosin (40 µg/kg/day over one month) on urinary bladder was examined in female rats with modeled chronic infravesical obstruction (IVO) produced by graduated mechanical constriction of the proximal urethral segment. In one month, IVO induced a pronounced vesical hypertrophy both in treated and untreated rats that manifested in increased bladder weight and capacity, the latter increment being pronouncedly greater in treated rats. In untreated IVO rats, infusion cystometry revealed elevated basal intravesical pressure of void bladder P0, markedly increased maximal (premicturitional) pressure Pmax, and increased amplitude of spontaneous oscillations of intravesical pressure ΔPdet in filled bladder. Doxazosin produced no significant effect on Pmax rise during IVO, but prevented elevation of P0 and increment of ΔPdet in filled bladder. During gradual filling of urinary bladder in control (intact) rats, the parasympathetic vesical influences increased progressively, while in untreated IVO rats, the adrenergic influences prevailed even at maximal filling of the bladder. In IVO rats, doxazosin prevented the bias of the sympathetic-parasympathetic balance in the filled bladder in favor of sympathetic influences, but did not prevent this bias in a void bladder. It is hypothesized that α-adrenoblockers improve micturition during IVO caused by benign prostatic hyperplasia not only by decreasing the urethral resistance to urine flow due to down-regulation of prostate smooth muscle tone, but also by a direct action of these blockers on detrusor adrenergic receptors and central structures involved in urinary bladder control.

Normalized Urinary Flow at Puberty after Tubularized Incised Plate Urethroplasty for Hypospadias in Childhood.

PURPOSE: An obstructive urinary flow pattern is frequently seen after tubularized incised plate urethroplasty for hypospadias. However, the significance of this finding has not been determined and long-term results are few. We describe postoperative long-term uroflowmetry results after puberty in males who underwent tubularized incised plate urethroplasty in childhood. MATERIALS AND METHODS: A total of 126 boys underwent tubularized incised plate urethroplasty for distal penile to mid shaft hypospadias at Queen Silvia Children's Hospital in Gothenburg between 1999 and 2003. Of the patients 48 were toilet trained at surgery. We report on 40 patients who had data available at 2 and 12 months postoperatively, 7 years postoperatively and at puberty (median age 15.0 years, range 13.7 to 17.1). Of the patients 31 had distal and 9 had mid penile hypospadias. Clinical examination, urinary medical history, uroflowmetry and ultrasound measuring residual urine were performed. Maximum urinary flow was correlated to age and voided volume, using Miskolc nomograms for comparison of percentiles. RESULTS: At 1 year postoperatively 15 boys (37.5%) had normal urinary flow (above 25th percentile), compared to 16 (40%) at 7 years and 38 (95%) at puberty (p <0.0001). Improvement was significant in patients with distal (p <0.0001) and mid penile hypospadias (p = 0.008), as well as in patients who did (p = 0.0078) and did not undergo intervention (p <0.0001). During followup 5 patients underwent meatotomy due to obstructive symptoms and 4 underwent dilation. Three of these 9 patients had lichen sclerosus. CONCLUSIONS: There is great potential for normalization of urinary flow at puberty for boys with hypospadias treated with tubularized incised plate urethroplasty. Unless symptoms occur, a conservative approach seems preferable.

Comparison of flowrates and voided volumes during non-instrumented uroflowmetry and pressure-flow studies in women with stress incontinence.

AIMS: The Blaivas-Groutz nomogram defines voiding obstruction in women using Qmax from the NIF and the maximum detrusor pressure (Pdetmax ) from the PFS. The aim of this study was to understand the relationship between NIF and PFS maximum flow rates in women with stress incontinence. METHODS: We analyzed the UDS of 597 women with stress-dominant urinary incontinence. Each subject underwent a NIF and then a PFS. Mixed model was used to test the hypothesis that the relationship between flow rates and voided volume (VV) were similar for NIF and PFS. RESULTS: There were 452 subjects with both NIF and PFS studies that met the inclusion criteria and had max flow rate (Qmax ) for both NIF and PFS. The mean age was 53. Overall, higher VV were observed during PFS compared to NIF and subjects had higher Qmax with NIF compared to PFS. The relationship between Qmax and VV was significantly different between NIF and PFS (P < 0.004). At 200 ml, NIF Qmax was 14% higher than PFS Qmax and this difference increased to 30% at 700 ml. CONCLUSION: The difference between PFS Qmax and NIF Qmax increases as VV increase. As a result, values from PFS and NIF cannot be used interchangeably as has been suggested in the Blaivas-Groutz nomogram for obstruction in women.

The management of prostatic obstruction with urethral stents.

INTRODUCTION: Elderly men with multiple comorbidities may be unfit to undergo surgical management of benign prostatic obstruction (BPO). Permanent and temporary prostatic stents have been developed as an alternative to chronic indwelling catheters in men unfit for surgery. MATERIALS AND METHODS: Herein we review the past and present literature on the role and effectiveness of prostatic stents in the treatment of BPO. RESULTS: Permanent prostatic stents have largely been abandoned in North America due to unfavorable outcomes and improved technologies to allow for treatment of BPO. Currently, the temporary Spanner stent is the only available stent on the market, but its effectiveness has mostly been documented for temporary relief of tissue edema following minimal invasive ablative treatments for BPO. CONCLUSIONS: The advent of well-tolerated surgical treatments for BPO (KTP laser vaporization, bipolar TURP, urethral lift devices) has diminished the need for permanent prostatic stents. The temporary Spanner stent is an alternative to urethral catheter, but requires adequate detrusor function and can cause irritative symptoms.

Mechanisms of pelvic organ cross-talk: impact of urethral ligation on the inhibitory rectovesical reflex.

PURPOSE: The existence of an inhibitory rectovesical reflex elicited by noxious colorectal afferent input was previously documented in an isovolumetric cystometry model with a ligated urethra. We compared the effect of noxious colorectal distension on bladder cystometry with an open and a ligated urethra. MATERIALS AND METHODS: We used female Sprague Dawley® rats anesthetized with urethane. The effect of noxious (60 mm Hg) colorectal distension on intermittent and continuous cystometry with an open urethra was studied and then compared to inhibiting isovolumetric bladder contractions in the same rat after ligating the urethra. We evaluated volume, the pressure micturition threshold, the intercontraction interval, bladder contraction frequency and amplitude of micturition contractions. RESULTS: Noxious colorectal distension at 60 mm Hg did not significantly influence volume or the pressure micturition threshold during intermittent cystometry. It also did not influence the pressure micturition threshold, the intercontraction interval or bladder contraction frequency during continuous cystometry. After urethral ligation 60 mm Hg colorectal distension inhibited isovolumetric bladder contraction frequency in the same rat (mean ± SEM 0.363 ± 0.207 vs 0.886 ± 0.106 contractions per minute, p <0.05). This inhibition persisted a mean of 289.08 ± 91.24 seconds after deflating the rectal balloon. CONCLUSIONS: The inhibitory rectovesical reflex elicited by noxious colorectal distension clearly occurred in an isovolumetric bladder model with a ligated urethra but only to a negligible extent in filling related voiding contractions. Our results suggest that the inhibitory rectovesical reflex, most likely at the level of the lumbosacral spinal cord, is the result of an additive noxious urethral and colonic afferent stimulus.

Improved model for the establishment and evaluation of detrusor overactivity in female Wistar rats.

OBJECTIVE: To improve the model for establishment and evaluation of detrusor overactivity in female Wistar rats. MATERIALS AND METHODS: We ligated the perineal urethra of female Wistar rats and then performed filling cystometry. The probability of detrusor overactivity, bladder capacity, peak voiding pressure and histological changes were investigated. RESULTS: Detrusor overactivity ratio of the obstruction group was 32.4%. Bladder capacity increased from 0.273 ± 0.036 mL in control group to 0.89 ± 0.19 mL in detrusor overactivity group (P < 0.001), and peak voiding pressure increased from 45.9 ± 4.1 cm.H2O to 63.5 ± 17.4 cm.H2O (P = 0.007). For obstruction group, compared to no detrusor overactivity rats, detrusor overactivity rats had higher bladder capacity (0.89 ± 0.19 mL versus 0.43 ± 0.09 mL, P < 0.001) and higher peak voiding pressure (63.5 ± 17.4 cm.H2O versus 44.8 ± 6.2 cm.H2O, P = 0.005). Detrusor overactivity rats were classified according to peak voiding pressure (49.2 ± 4.2 cm.H2O versus 80.8 ± 7.1cm.H2O, P < 0.001). Moreover, bladder weight increased significantly in detrusor overactivity rats (P = 0.003, P = 0.028) and detrusor histological hypertrophy was observed. CONCLUSIONS: Ligating perineal urethra and filling cystometry with intra-urethral cannula approach is a simple and easily reproducible method to establish and evaluate the model of detrusor overactivity in rats.

Microalbuminuria and hyperfiltration in subjects with nephro-urological disorders.

BACKGROUND: Microalbuminuria (MA) has been shown to be an early biomarker of renal damage. It is postulated that MA is the early result of hyperfiltration, which could evolve into glomerular sclerosis and renal failure if hyperfiltration is left untreated. We hypothesized that MA is a good indicator of hyperfiltration in children with kidney disorders, obviating the need to calculate the filtration fraction (FF). METHODS: A total of 155 children or young adults were prospectively included [42 single kidney (SK), 61 vesico-ureteral reflux, 23 obstructive uropathies, 29 other kidney diseases]. We measured inulin, para-aminohippuric acid clearances, FF and MA. Prediction of hyperfiltration was explored by studying the association between the FF and other variables such as urinary albumin (Alb), urinary albumin-creatinine ratio (ACR) and creatinine clearance. RESULTS: A significant but weak association between urinary Alb or ACR and FF was found in subjects with an SK (Spearman correlation coefficients 0.32 and 0.19, respectively). Multivariate analysis also showed that urinary Alb and ACR significantly predict FF only in subjects with an SK (r(2) = 0.17, P = 0.01 and r(2) = 0.13, P = 0.02, respectively). This holds true only in subjects with an SK and inulin clearance >90 mL/min/1.73 m(2) (r(2) = 0.41, P < 0.001). There was no association between creatinine clearance and FF. CONCLUSIONS: MA is not associated with FF in our subjects with nephro-urological disorders, except in those with an SK, where the association is weak, indicating that MA is due to other mechanisms than high FF and cannot predict hyperfiltration in such groups.

Predictor of de novo stress urinary incontinence following TVM procedure: a further analysis of preoperative voiding function.

INTRODUCTION AND HYPOTHESIS: The purpose of this study was to evaluate the predictors of de novo stress urinary incontinence (SUI) in patients undergoing a tension-free vaginal mesh procedure (TVM) for pelvic organ prolapse (POP). METHODS: Sixty-five patients without SUI were assessed with regard to voiding function by a pressure flow study and clinical characteristics. RESULTS: The mean age of the patients was 67 ± 8.3. Of the 65 patients, 41 (63 %) maintained urinary continence postoperatively and 24 (37 %) showed de novo SUI. In univariate analysis, the de novo SUI group included a significantly higher proportion of patients with preoperative obstruction, defined as moderate or greater obstruction according to the Blaivas nomogram (29 vs 7 %, P = 0.035). In multivariate analysis, urethral obstruction was an independent predictor of de novo SUI with an odds ratio of 12.616 (95 % confidence interval 1.580-268.731). CONCLUSIONS: Preoperative evaluation of urethral obstruction will contribute to prediction of de novo SUI combined with a conventional diagnosis of occult SUI.

Impact of partial urethral obstruction on bladder function: time-dependent changes and functional correlates of altered expression of Ca²âº signaling regulators.

In animal models of partial urethral obstruction (PUO), altered smooth muscle function/contractility may be linked to changes in molecules that regulate calcium signaling/sensitization. PUO was created in male rats, and urodynamic studies were conducted 2 and 6 wk post-PUO. Cystometric recordings were analyzed for the presence or absence of nonvoiding contractions [i.e., detrusor overactivity (DO)]. RT-PCR and Western blots were performed on a subpopulation of rats to study the relationship between the expression of RhoA, L-type Ca(2+) channels, Rho kinase-1, Rho kinase-2, inositol 1,4,5-trisphosphate, ryanodine receptor, sarco(endo)plasmic reticulum Ca(2+)-ATPase 2 and protein kinase C (PKC)-potentiated phosphatase inhibitor of 17 kDa, and urodynamic findings in the same animal. Animals displayed DO at 2 (38%) and 6 wk (43%) post-PUO, increases were seen in in vivo pressures at 2 wk, and residual volume at 6 wk. Statistical analysis of RT-PCR and Western blot data at 2 wk, during the compensatory phase of detrusor hypertrophy, documented that expression of molecules that regulate calcium signaling and sensitization was consistently lower in obstructed rats without DO than those with DO or control rats. Among rats with DO at 2 wk, linear regression analysis revealed positive correlations between in vivo pressures and protein and mRNA expression of several regulatory molecules. At 6 wk, in the presence of overt signs of bladder decompensation, no clear or consistent alterations in expression of these same targets were observed at the protein level. These data extend prior work to suggest that molecular profiling of key regulatory molecules during the progression of PUO-mediated bladder dysfunction may shed new light on potential biomarkers and/or therapeutic targets.