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

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.

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.

Anterior Urethral Valve - A Commonly Misdiagnosed Entity in Adolescent Boys.

Anterior urethral valves are a rare cause of obstructed voiding in adolescent children and are often unheard by adult urologists. In this case report, we discuss the management of two adolescent patients who were referred to us with obstructive voiding symptoms with a diagnosis of neurogenic bladder and posterior urethral valves respectively but on evaluation were found to have anterior urethral valves. This article highlights the need for considering anterior urethral valve as an important differential diagnosis in children and adolescents presenting with obstructive voiding symptoms so as to avoid delay in diagnosis and management in young boys.

Prenatal extravasation of urine seems to preserve renal function in boys with posterior urethral valves.

INTRODUCTION: A posterior urethral valve (PUV) may lead to extravasation of urine, resulting in prenatal ascites and/or perirenal urinoma. Extravasation has been presumed to act as a pop-off mechanism, preserving renal function, but previous reports addressing this presumption have been inconclusive. AIM OF STUDY: The present study compares renal function in patients with PUV with and without extravasation. MATERIAL AND METHODS: Sixty boys with a confirmed diagnosis of PUV as neonates (gestational age [GA]<44 weeks) throughout 2001-2016 were included. Clinical data were collected from medical records. Renal function was assessed by nadir plasma creatinine, creatinine at the last follow-up, and glomerular filtration rate (GFR) at the last follow-up. The GFR was estimated using the Schwartz formula. Renal function was classified according to the kidney disease: improving global outcomes (KDIGO) guidelines' grades of chronic kidney disease (CKD). Glomerular filtration rate > 90 ml/min/1.73m2 at the last follow-up was classified as normal renal function. RESULTS: Twelve patients (20%) had ascites and/or urinoma, and 48 (80%) did not. GA and birth weight were not different in patients with and without extravasation. PUV was suspected from prenatal ultrasound findings in 66.7% of the patients in both groups. Median nadir creatinine was 21 (range, 11-33) µmol/L in boys with ascites/urinoma, and all values were within the age-adjusted reference values. Nadir creatinine was 23 (14-199) µmol/L in boys without extravasation, and it was above the normal range in 14 boys. The incidence of elevated nadir creatinine was significantly different in the two groups (p < 0.025). One of the 12 patients with extravasation developed chronic renal failure (CKD 3). In the group of 48 patients without extravasation, 20 (42%) had chronic renal failure grade 2-5, and among these, 5 patients have had a renal transplant (CKD grade 5). The prevalence of CKD grade 2-5 was statistically different in the two groups (p = 0.03). These findings are presented in the summary figure. CONCLUSION: Extravasation of urine was found in 12 of 60 (20%) boys with PUV. These patients had significantly lower prevalence of CKD at the last follow-up than patients without extravasation. This finding is important in prenatal counseling. It also indicates that prenatal decompression of the bladder and upper tract is beneficial in patients with PUV, which is relevant to the discussion of prenatal intervention in these fetuses.

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.

[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.

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.

Long-term Impacts of Concurrent Posterior Urethral Valve Ablation and Bladder Neck Incision on Urinary Continence and Ejaculation.

OBJECTIVE: To assess the long-term impacts of bladder neck incision (BNI) on continence and ejaculatory function of adults who underwent concurrent posterior urethral valve (PUV) ablation and BNI during childhood. MATERIALS AND METHODS: A retrospective chart review was performed to find all adult patients with relevant history. All patients had undergone BNI at 6 o'clock proximal to the verumontanum with caution to leave the adventitia and verumontanum untouched. Charts were reviewed and attempts were made to contact those ≥18 years old for follow-up. Patients were specifically evaluated for lower urinary tract symptoms and ejaculatory condition. RESULTS: Among patients treated for PUV between 1998 and 2015 in our center, 21 were ≥18 years old at the time of assessment. Until February 2016, we were able to contact 18 patients, all of whom agreed to participate. Mean age was 21.1 ± 2.9 years with a mean follow-up of 12.5 ± 4.8 years. None of those contacted had incontinence or dry ejaculations. All considered their ejaculations normal and only one complained of weak ejaculations. Four of 5 patients who consented to perform a semen analysis had normal tests and 1 had low sperm count with abnormal motility. CONCLUSION: BNI is not associated with additional risk of incontinence and dry ejaculation in early adulthood and preserves antegrade ejaculation. Concomitant valve ablation with BNI may provide additional benefits in care of PUV children, especially those with prominent bladder neck and poor bladder function at presentation.

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.

Effect of Selective Prostaglandin E2 EP2 Receptor Agonist CP-533,536 on Voiding Efficiency in Rats with Midodrine-Induced Functional Urethral Obstruction.

OBJECTIVES: We investigated the effect of the selective prostaglandin E2 EP2 receptor agonist CP-533,536 on voiding efficiency in rats with midodrine-induced functional urethral obstruction. METHODS: The effect of CP-533,536 (0.03-0.3 mg/kg, intravenous [i.v.]) on urethral perfusion pressure (UPP) was investigated in anesthetized rats pre-treated with midodrine (1 mg/kg, i.v.), which forms an active metabolite that acts as an α1 -adrenoceptor agonist. The effect of CP-533,536 (0.03-0.3 mg/kg, i.v.) on cystometric parameters was also investigated in anesthetized rats. In addition, the effect of CP-533,536 (0.03-0.3 mg/kg, i.v.) on residual urine volume (RV) and voiding efficiency (VE) was investigated in conscious rats treated with midodrine (1 mg/kg, i.v.). RESULTS: CP-533,536 dose-dependently decreased UPP elevated by midodrine in anesthetized rats. In contrast, CP-533,536 did not affect maximum voiding pressure, intercontraction interval, or intravesical threshold pressure. In conscious rats, midodrine (1 mg/kg, i.v.) markedly increased RV and reduced VE. CP-533,536 dose-dependently ameliorated increases in RV and decreases in VE induced by midodrine. CONCLUSIONS: These results suggest that a selective EP2 receptor agonist could ameliorate the elevation of RV and improve the reduction of VE in rats with functional urethral obstruction caused by stimulation of α1 -adrenoceptors. The mechanism of action might be not potentiation of bladder contraction but rather preferential relief of urethral constriction.

Comparative Influence of Imidafenacin and Oxybutynin on Voiding Function in Rats with Functional Urethral Obstruction.

An antimuscarinic therapy may increase the risk of voiding dysfunction. However, it is unclear whether the relative risk of voiding dysfunction is different among antimuscarinics. Therefore we determined the potencies both in enhancing the bladder capacity (BC), effectiveness, and in decreasing the maximum urinary flow rate (Qmax), voiding dysfunction, to compare their therapeutic indices.Under urethane anesthesia, urinary flow rate was measured at distal urethra using an ultrasonic flow meter in female Sprague-Dawley rats with functional urethral obstruction induced by a continuous i. v. infusion of α1-adrenoceptor agonist A-61603 (0.03 µg/kg/min). In a separate group of urethane-anesthetized rats without urethral obstruction, an intermittent cystometry was performed to determine BC.Intravenous imidafenacin and oxybutynin produced a significant dose-dependent decrease in Qmax with the minimum doses of 0.03 and 1 mg/kg, respectively. Imidafenacin and oxybutynin markedly increased BC, with minimum doses of 0.01 and 3 mg/kg, respectively. At the minimum dose to increase BC, oxybutynin caused a significant increase in residual urine volume with a significant decrease in voiding efficiency, whereas imidafenacin had no influence on these values. The relative influence index, which is the ratio of the minimum influence dose between in decreasing of Qmax and in increasing of BC, of imidafenacin was 10 fold higher than that of oxybutynin.This study suggests that imidafenacin has a lower relative risk of voiding difficulty compared with oxybutynin in rats. These results provide new information that antimuscarinics may have varying degrees of impact on voiding difficulty.

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.

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.

Feline lower urinary tract disease in a German cat population. A retrospective analysis of demographic data, causes and clinical signs.

OBJECTIVE: To investigate epidemiologic data, clinical signs, results of urinalysis and causes of lower urinary tract disease in a German veterinary hospital population of cats and to determine if the demographic data, history, clinical signs and urinalysis results correlate with a particular etiology. MATERIALS AND METHODS: Cats presented with signs of feline lower urinary tract disease (FLUTD) with a documented history and physical examination, a complete urinalysis (urine specific gravity, urine dipstick and sediment, urine culture) of urine obtained by cystocentesis or catheterization, and diagnostic imaging of the urinary tract were included into the study. Cats that had received a previous treatment during the same episode of FLUTD were excluded. RESULTS: A total of 302 cats were included into the study. Cats with FLUTD presented throughout the seasons with similar frequency. The most common diagnosis was feline idiopathic cystitis (FIC) (55.0%), followed by bacterial urinary tract infection (UTI) (18.9%), urethral plug (10.3%) and urolithiasis (7.0%). Urethral obstruction was significantly more frequent in cats with FIC than in cats with UTI. Cats with FIC and urethral plugs were significantly younger and had significantly higher body weights than cats with UTI and neoplasia. FIC and urethral plugs were significantly more common causes of FLUTD in cats younger than 10 years compared to cats that were 10 years or older (65.2% versus [vs.] 35.8% and 13.3% vs. 3.0%), while the incidences of UTI and neoplasia increased with age (12.9% vs. 41.8% and 1.0% vs. 13.4%). CONCLUSION AND CLINICAL RELEVANCE: FIC and UTI are the most common diagnoses in cats with FLUTD, with a significant age-related difference in incidence.

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.

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 ± 0.036mL in control group to 0.89 ± 0.19mL in detrusor overactivity group (P < 0.001), and peak voiding pressure increased from 45.9 ± 4.1 cm.H2O to 63.5 ± 17.4cm.H2O (P = 0.007). For obstruction group, compared to no detrusor overactivity rats, detrusor overactivity rats had higher bladder capacity (0.89 ± 0.19mL versus 0.43 ± 0.09mL, P < 0.001) and higher peak voiding pressure (63.5 ± 17.4cm.H2O versus 44.8 ± 6.2cm.H2O, P = 0.005). Detrusor overactivity rats were classified according to peak voiding pressure (49.2 ± 4.2cm.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. .

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.

Antegrade pressure measurement of urinary tract in children with persistent hydronephrosis.

INTRODUCTION: Dilation of urinary tract occurs without the presence of obstruction. Diagnostic methods that depend on renal function may elicit mistaken diagnosis. Whitaker (1973) proposed the evaluation of urinary tract pressure submitted to constant flow. Other investigators proposed perfusion of renal pelvis under controlled pressure, making the method more physiological and reproducible. The objective of the present study was to evaluate the results of the anterograde pressure measurement (APM) of the urinary tract of children with persistent hydronephrosis after surgery suspected to present persistent obstruction. MATERIALS AND METHODS: Along 12 years, 26 renal units with persistent hydronephrosis after surgery (12 PUJ and 14 VUJ) were submitted to evaluation of the renal tract pressure in order to decide the form of treatment. Previous radionuclide scans with DTPA, intravenous pyelographies and ultrasounds were considered undetermined in relation to obstruction in 10 occasions and obstructive in 16. APM was performed under radioscopy through renal pelvis puncture or previous stoma. Saline with methylene blue + iodine contrast was infused under constant pressure of 40 cm H2O to fill the urinary system. The ureteral opening pressure was measured following the opening of the system and stabilization of the water column. RESULTS: Among the 10 cases with undetermined previous diagnosis, APM was considered non-obstructive in two and those were treated clinically and eight were considered obstructive and were submitted to surgery. Among the 16 cases previously classified as obstructive, nine confirmed obstruction and were submitted to surgery. Seven cases were considered non-obstructive, and were treated clinically, with stable DMSA and hydronephrosis. CONCLUSIONS: APM avoided unnecessary surgery in one third of the cases and was important to treatment decision in 100 %. We believe that this simple test is an excellent diagnostic tool when selectively applied mainly in the presence of functional deficit.

Antegrade pressure measurement of urinary tract in children with persistent hydronephrosis

INTRODUCTION: Dilation of urinary tract occurs without the presence of obstruction. Diagnostic methods that depend on renal function may elicit mistaken diagnosis. Whitaker (1973) proposed the evaluation of urinary tract pressure submitted to constant flow. Other investigators proposed perfusion of renal pelvis under controlled pressure, making the method more physiological and reproducible. The objective of the present study was to evaluate the results of the anterograde pressure measurement (APM) of the urinary tract of children with persistent hydronephrosis after surgery suspected to present persistent obstruction. MATERIALS AND METHODS: Along 12 years, 26 renal units with persistent hydronephrosis after surgery (12 PUJ and 14 VUJ) were submitted to evaluation of the renal tract pressure in order to decide the form of treatment. Previous radionuclide scans with DTPA, intravenous pyelographies and ultrasounds were considered undetermined in relation to obstruction in 10 occasions and obstructive in 16. APM was performed under radioscopy through renal pelvis puncture or previous stoma. Saline with methylene blue + iodine contrast was infused under constant pressure of 40 cm H2O to fill the urinary system. The ureteral opening pressure was measured following the opening of the system and stabilization of the water column. RESULTS: Among the 10 cases with undetermined previous diagnosis, APM was considered non-obstructive in two and those were treated clinically and eight were considered obstructive and were submitted to surgery. Among the 16 cases previously classified as obstructive, nine confirmed obstruction and were submitted to surgery. Seven cases were considered non-obstructive, and were treated clinically, with stable DMSA and hydronephrosis. CONCLUSIONS: APM avoided unnecessary surgery in one third of the cases and was important to treatment decision in 100%. We believe that this simple test is an excellent diagnostic tool when selectively applied mainly in the presence of functional deficit.