The Release of 24 h Infravesical Obstruction in Mice: Changes in Molecular, Morphological, and Functional Parameters for 14-Day Observation.

Bladder outlet obstruction (BOO) induces bladder dysfunction and altered bladder architecture. Irrespective of the release of the obstruction, persistent bladder dysfunction severely affects the quality of life. A better understanding of the repair process offers an opportunity to enhance postintervention management. We subsequently evaluated the postobstructive repair process in mice subjected to 24 h BOO followed by release. Male and female mice bladders were obstructed for 24 h by placing a clip around the bladder neck. After the release of obstruction, the mice were studied for 3, 7, and 14 days to observe the bladder repair process over time. Voiding frequency and volume were recorded using the voiding spot assay, and the transcutaneous glomerular filtration rate (tGFR) was measured. Fibrogenesis and associated gene expressions and altered protein levels were evaluated in the bladder using histology, quantatative polymerase chain reaction (qPCR), and Western blot analyses. Bladder wall thickness was increased in both genders over time but occurred later in female mice. Moreover, collagen deposition in the smooth muscle layer increased over time in both genders. Male mice showed a decreased average voided volume at 3 days post release, while female mice showed no significant change during the time course. Fibrosis-related molecular events, including upregulation of fibronectin (FN) protein and Collagen-3 (Col-3) mRNA expression, were transient and normalized again at 14 days in both genders. Transforming growth factor-ß (TGF-ß) and bone morphogenic protein (BMP)-7 mRNA expressions were upregulated at 14 days post release in both genders. Transcutaneous GFR remained normal during the time course. Release of 24 h BOO initiated a bladder remodeling process. The animal model enables a wide range of experiments to study bladder remodeling, and gender differences offer potential targets for understanding bladder fibrosis and adaptation with BOO.

How can we develop a more clinically useful and robust algorithm for diagnosing and treating nocturia? ICI-RS 2017.

AIMS: Nocturia, or waking up at night to void, is a highly prevalent and bothersome symptom. Currently, there is a lack of clear and consistent recommendations regarding evaluation and management of nocturia. The aim of this report is to discuss how to fill the gaps in our knowledge in order to develop a practical patient-oriented diagnostic and therapeutic algorithm for nocturia. METHODS: This paper is a report of the presentations and subsequent discussion of a Think Tank session at the annual International Consultation on Incontinence Research Society (ICI-RS) in June 2017 in Bristol. RESULTS AND CONCLUSION: Further investigations are needed to better understand the pathophysiology of nocturia, to allow improvement in diagnosis, and to optimize treatment by increasing efficacy and reducing adverse events. Patient-oriented practical guidelines on nocturia are needed to help clinicians from different disciplines diagnose and treat nocturia.

What is the utility of urodynamics, including ambulatory, and 24 h monitoring, in predicting upper urinary tract damage in neuro-urological patients and other lower urinary tract dysfunction? ICI-RS 2017.

AIMS: This article focuses on how, and if, urodynamics can help to identify which kidneys are in danger of deteriorating in function and also gives recommendations for future research. METHODS: At the International Consultation on Incontinence-Research Society (ICI-RS) in 2017, a multi-disciplinary group presented a literature search of what is known about the utility of Urodynamics, including ambulatory, and 24 h monitoring, in predicting upper urinary tract damage in neuro-urological patients and other lower urinary tract dysfunctions. Wider discussions regarding knowledge gaps, and ideas for future research ensued and are presented in this paper along with a review of the evidence. RESULTS: The current treatment strategy both in congenital and acquired neurogenic bladder is rather aggressive and successful when addressing hazards to kidney function. This article has highlighted uncertainties concerning the use of 40 cmH2O DLPP and even the lower value of 20. The current literature suggests that patients with spina bifida and those with spinal cord injury have a higher risk of developing upper urinary tract damage and kidney function impairment than those with multiple sclerosis. CONCLUSIONS: Future research should focus on less invasive methods to assess the risk to the upper and lower urinary tract such as urine and serum measurements of cytokines that are involved in the pathophysiology of urinary tract impairment.

ICS educational module: Pressure flow study in children.

AIMS: To introduce the standard procedure and results interpretation of pressure/flow study (PFS) in children. METHODS: The literature on PFS in children in PubMed for the last 20 years was reviewed. The updated knowledge on PFS in children in children regarding indication, preparation, technique, and interpretation were summarized. RESULTS: This educational module explains when and how to do a PFS and how to analyze the results. All requirements and instructions for the PFS in children described in this document follow ICS reports on Good Urodynamic Practice and urodynamic equipment performance as well as guidelines from the ICCS. PFS can be obtained subsequent to filling cystometry with no specific additional equipment (apart from a flowmeter) or patient preparation needed. It requires both vesical and intra-abdominal pressures being recorded. Information from clinical history, physical examination, voiding diaries, and free uroflowmetry with or without perineal patch EMG and pertinent imaging results should be available before undertaking urodynamic testing. CONCLUSIONS: Following ICS and ICCS guidelines, PFS is an easy procedure and a useful tool to provide information on voiding function in children.

Male bladder outlet obstruction: Time to re-evaluate the definition and reconsider our diagnostic pathway? ICI-RS 2015.

The diagnosis of bladder outlet obstruction (BOO) in the male is dependent on measurements of pressure and flow made during urodynamic studies. The procedure of urodynamics and the indices used to delineate BOO are well standardized largely as a result of the work of the International Continence Society. The clinical utility of the diagnosis of BOO is however, less well defined and there are several shortcomings and gaps in the currently available medical literature. Consequently the International Consultation on Incontinence Research Society (ICI-RS) held a think tank session in 2015 entitled "Male bladder outlet obstruction: Time to re-evaluate the definition and reconsider our diagnostic pathway?" This manuscript details the discussions that took place within that think tank setting out the pros and cons of the current definition of BOO and exploring alternative clinical tests (alone or in combination) which may be useful in the future investigation of male patients with lower urinary tract symptoms. The think tank panel concluded that pressure-flow studies remain the diagnostic gold-standard for BOO although there is still a lack of high quality evidence. Newer, less invasive, investigations have shown promise in terms of diagnostic accuracy for BOO but similar criticisms can be levelled against these tests. Therefore, the think tank suggests further research with regard to these alternative indicators to determine their clinical utility.

Combination treatment of nocturnal enuresis with desmopressin and indomethacin.

BACKGROUND: We investigated the effect of combining indomethacin and desmopressin in treating children with monosymptomatic nocturnal enuresis (MNE) and desmopressin-resistant nocturnal polyuria. METHODS: Twenty-three children with MNE, nocturnal polyuria, and partial or no response to desmopressin were recruited from incontinence clinics of our tertiary referral center. We used a randomized single-arm crossover placebo-controlled study design consisting of two 3-week treatment periods with a combination of desmopressin (0.4 mg) and indomethacin (50 mg) or desmopressin and placebo at bedtime. Home recordings at baseline and for the final 2 weeks of each treatment period were performed and included nocturnal urine output measurements. The number of dry nights achieved and reduction in the nocturnal urine output were the main effect parameters. Student's t test and Pearson's correlation coefficient were used for statistical analysis. RESULTS: The addition of indomethacin to desmopressin significantly reduced nocturnal urine output (from 324 ± 14 ml to 258 ± 13 ml, p < 0.001). This did not lead to more dry nights in all children, and we found no statistically significant reduction in enuresis frequency (from 68 % ± 0.1 to 56 % ± 0.1, p = 0.24). CONCLUSIONS: Addition of indomethacin to desmopressin can further reduce nocturnal urine output in children with MNE and desmopressin-resistant nocturnal polyuria. The combination treatment does not, however, improve outcome in terms of frequency of nights with enuresis. The dissociation of antidiuretic and antienuretic effect may reflect nocturnal bladder reservoir dysfunction in children who present with normal daytime bladder function.

Rectal motility in pediatric constipation.

OBJECTIVES: Constipation is a common disorder in children, but little is known about its etiology. Rectal impedance planimetry determines segmental rectal cross-sectional area (CSA) and pressure, allowing detailed description of rectal motility. The aim of the present study was to compare rectal motility in healthy and constipated children. METHODS: We analyzed data from 10 children (1 girl) with constipation according to the Rome III criteria, mean age 8.8 years (standard deviation ±â€Š1.2), and 10 healthy children (5 girls), mean age 9.9 years (standard deviation ±â€Š1.5). CSA was determined at 3 levels (4, 5.5, and 7 cm from the anal verge). The resting rectal motility was recorded for 30 minutes followed by a distension protocol to assess compliance. Runs of phasic rectal contractions were defined as changes of >10% from baseline CSA and lasting at least 2 minutes. Rectal dimensions were expressed as mean CSA. RESULTS: A low-amplitude contraction pattern (3%-5% of baseline CSA) with a frequency of 6 to 8/minute was present in all of the children. There was significantly more time with phasic rectal contractions in constipated children (median 38%, range [0-100]) compared with healthy children (median 8.8%, range [0-57]) (P < 0.05). The rectal CSA was higher in constipated children (median 1802 mm [range 1106-2948]) compared with healthy children (1375 mm [range 437-1861]) (P < 0.05), but compliance did not differ (constipated: median 38 mm/H2O [range 12-86] vs healthy 33 mm/H2O [range 10-63]) (P = 30). CONCLUSIONS: In children with constipation, we found phasic rectal contractions for a significantly longer period compared with healthy children, and their rectum is larger than normal.

Outcome of a standardized approach to childhood urinary symptoms-long-term follow-up of 720 patients.

AIMS: To investigate the relevance of enuresis subtyping for selection of treatment modality and for long-term outcome in a large consecutive patient cohort. MATERIALS AND METHODS: We included all patients referred for urinary incontinence during a 5-year period but excluding recurrent urinary tract infections (UTI). Type and severity of incontinence, prior history, results of examinations performed, number of visits, and effect of all treatments provided, were included in a clinical database. RESULTS: Seven hundred twenty children aged 4-16 years (mean 8.5 ± 2.2 years, 239 girls) were included in the analysis (42% with monosymptomatic (MNE), 55% with non-MNE, and 3% with isolated daytime incontinence). Initial evaluation revealed only few underlying causes (one neurological and eight anatomical). Investigations showed significant differences between MNE and non-MNE patients as both maximal voided volume and nocturnal urine volume was lower in non-MNE patients (P < 0.001). Follow-up for average 1,587 days (3.4 years) was performed in 660 (92%) patients. A higher number of visits and a longer treatment period were needed for non-MNE patients (on average 4.7 ± 2.8 visits) than MNE patients (3.1 ± 1.6 visits, P < 0.001). The most common treatment regimen that resulted in dryness in both MNE (40%) and non-MNE (36%) was the alarm system. Interestingly, of the 539 patients who initially were referred due to desmopressin resistance 177 (33%) of these were dry on desmopressin monotherapy. CONCLUSIONS: The study indicated that MNE and non-MNE are two distinct disease entities with different optimal treatments and showed that the latter patients are more difficult and time-consuming to manage.

Effect of indomethacin on desmopressin resistant nocturnal polyuria and nocturnal enuresis.

PURPOSE: We evaluated the acute effect of indomethacin on renal water and solute handling in children with coexisting monosymptomatic nocturnal enuresis and desmopressin resistant nocturnal polyuria, and in healthy controls. MATERIALS AND METHODS: A total of 23 subjects were recruited, consisting of 12 children with monosymptomatic nocturnal enuresis and nocturnal polyuria with partial or no response to desmopressin, and 11 age matched controls. Children completed a 48-hour inpatient study protocol consisting of fractional urine collections and blood samples. Sodium and water intake were standardized. During the second night a dose of 50 mg indomethacin was administered orally before bedtime. Diuresis, urine osmolalities, clearances and fractional excretions were calculated for sodium, potassium, urea, osmoles and solute-free water. Renin, angiotensin II, aldosterone and atrial natriuretic peptide were measured in plasma. Prostaglandin E(2) was measured in urine. RESULTS: Indomethacin markedly decreased the nocturnal sodium, urea and osmotic excretion in children with enuresis and controls. The overall effect on nocturnal urine output was inconsistent in the group with enuresis. Subjects in whom nocturnal diuresis was decreased following administration of indomethacin remained dry. CONCLUSIONS: Prostaglandin inhibition leads to antidiuresis, reducing the amount of sodium, urea and osmotic excretion in children with monosymptomatic nocturnal enuresis and desmopressin resistant nocturnal polyuria. The sodium regulating hormones do not seem to mediate these processes. The overall effect in desmopressin nonresponders with nocturnal polyuria is variable. The extent to which indomethacin can be applied in the treatment of enuresis needs further evaluation.

The effect of desmopressin on renal water and solute handling in desmopressin resistant monosymptomatic nocturnal enuresis.

PURPOSE: We sought to evaluate the effect of desmopressin on renal water and solute handling in children with monosymptomatic nocturnal enuresis and desmopressin resistant nocturnal polyuria compared to healthy controls. MATERIALS AND METHODS: A total of 12 patients with enuresis and nocturnal polyuria, normal bladder reservoir function and no response to desmopressin, and 10 age matched controls were enrolled in the study. Children were admitted to the hospital for a 48-hour protocol comprising urine collections and blood sampling. Sodium and water intake was standardized. During the second night children received 40 mug intranasal desmopressin. Parameters characterizing the renal water and solute handling were measured and compared between baseline nights and nights with desmopressin. RESULTS: Desmopressin markedly reduced nocturnal urine output in patients with enuresis, minimizing sodium, urea and overall solute excretion, despite the fact that these children were unresponsive to desmopressin at home. This effect on renal sodium handling was not mediated by atrial natriuretic peptide, angiotensin II, aldosterone or renin. Desmopressin did not influence urinary prostaglandin E(2) excretion. The antinatriuretic effect was seen only in patients with enuresis, and it was directly correlated with the reduction in urine output. CONCLUSIONS: Children with nocturnal enuresis and nocturnal polyuria who do not exhibit adequate response to desmopressin at home seem to respond well to the agent at the clinic. The effect of desmopressin in children with enuresis seems largely dependent on reductions in the amount of sodium excreted. Sodium regulating hormones remained unaffected by desmopressin, indicating a possible direct effect of the agent on renal sodium handling.

Combination of the enuresis alarm and desmopressin: second line treatment for nocturnal enuresis.

PURPOSE: We sought to evaluate the combination of the enuresis alarm and desmopressin in treating children with enuresis. MATERIALS AND METHODS: A retrospective analysis was performed on data from 423 children treated at our clinics with the enuresis alarm during the years 2000 to 2004. Frequency volume charts and desmopressin titration facilitated characterization of the participants using the current International Children's Continence Society standardization. Children were treated with the enuresis alarm as monotherapy before the addition of desmopressin, which commenced after 6 weeks in patients exhibiting inadequate response to alarm or after 2 weeks in patients experiencing multiple enuretic episodes per night or showing no indication of improvement. RESULTS: Of the initial population 315 children (74%) were treated only with alarm, of whom 290 became dry. A total of 108 children (26%) were treated with a combination of alarm and desmopressin, with 80 being cured. Children dry on alarm therapy were not different from those needing the addition of desmopressin in terms of demographics. Children dry on desmopressin plus alarm had higher average nocturnal urine production on wet nights (303 +/- 12 ml compared to 269 +/- 5 ml, p <0.001). Maximum voided volume before treatment corrected for age was not different between children dry on alarm and those dry on combination therapy (0.84 +/- 0.02 compared to 0.86 +/- 0.05, not significant). CONCLUSIONS: Children needing the addition of desmopressin have a higher nocturnal urine production on wet nights but do not seem to differ in terms of bladder reservoir function characteristics.

Urinary calcium excretion in healthy children and children with primary monosymptomatic nocturnal enuresis.

PURPOSE: We investigated the role of urinary Ca excretion in monosymptomatic nocturnal enuresis, and defined normality and intra-individual variability in Ca excretion in healthy children. MATERIALS AND METHODS: We included 46 Danish children with desmopressin resistant nocturnal enuresis and 96 healthy controls. We performed fractional urine collections at home during 2 days in controls or during hospitalization in children with enuresis. Urine volume, osmolality, and Ca and creatinine measurements were performed and Ca-to-creatinine ratios were calculated and compared between groups. Based on nocturnal urine output children with enuresis were characterized as having polyuria (nocturnal urine volume greater than 130% of expected bladder capacity) or not having polyuria. RESULTS: We did not find any differences in controls compared with children with enuresis who did not and did have nocturnal polyuria in daytime Ca excretion (mean +/- SE 0.121 +/- 0.012, 0.078 +/- 0.014 and 0.095 +/- 0.020 mg/mg creatinine), nighttime Ca excretion (0.115 +/- 0.011, 0.092 +/- 0.019 and 0.139 +/- 0.029 mg/mg creatinine) or 24-hour Ca excretion (0.118 +/- 0.011, 0.083 +/- 0.014 and 0.106 +/- 0.020 mg/mg creatinine, respectively). Urinary Ca excretion was not influenced by patient age, sex or body weight and, furthermore, we did not find evidence of diurnal variation. However, we observed considerable intra-individual variability in diurnal, nocturnal and total 24-hour urinary Ca-to-creatinine ratios. CONCLUSIONS: These observations contradict several previous reports and speculations on a role of Ca in the pathogenesis of nocturnal enuresis.

Circadian variation of angiotensin II and aldosterone in nocturnal enuresis: relationship to arterial blood pressure and urine output.

PURPOSE: We investigated the circadian rhythm of solute excretion and regulating hormones as well as blood pressure in patients with monosymptomatic nocturnal enuresis. MATERIALS AND METHODS: We included 15 patients with a mean age +/- SE of 13.4 +/- 0.9 years who had monosymptomatic nocturnal enuresis with at least 3 wet nights weekly and a control group of 10 healthy children with a similar age and sex distribution. During inpatient circadian studies urine was collected during 6 periods and blood was drawn at 7 time points during 24 hours. Heart rate and blood pressure was recorded with an ambulatory blood pressure monitor every 30 to 60 minutes. RESULTS: The total patient group excreted a significantly larger nocturnal urine volume than controls (p <0.01). Five patients had marked nocturnal polyuria (nocturnal urine volume greater than the mean in the control group +2 SD), whereas urine output in the remaining patients without polyuria were similar to controls. Nocturnal polyuria was caused mainly by increased nocturnal solute excretion, especially Na. Serum aldosterone and plasma angiotensin II showed a marked circadian rhythm in normal children with a nocturnal increase concomitant with a significant decrease in mean arterial blood pressure during sleep. In contrast, the group of patients with nocturnal polyuria showed a lack of circadian rhythm in all excretion variables as well as an attenuated rhythm in plasma angiotensin II and mean arterial blood pressure. Interestingly this group had normal circadian rhythms of the circadian rhythm markers plasma cortisol and heart rate. CONCLUSIONS: The study suggests that an abnormally large nocturnal excretion of Na caused by selectively attenuated circadian rhythms of Na regulating hormones might be an important pathogenic factor in monosymptomatic nocturnal enuresis.

The role of renal resistive index measures in the diagnostic work up of congenital hydronephrosis.

OBJECTIVE: To evaluate the role of renal resistive index (RI) measures in the diagnostic work up of congenital hydronephrosis. METHODS AND MATERIALS: Seventeen neonatal pigs were randomized to either left-sided partial unilateral ureteral obstruction (n=12) or sham operation (n=5) at 2 weeks of age. Serial investigations including B-mode ultrasound, RI measures and combined clearance/renographic evaluations were performed at 4, 12 and 24 weeks of age under light sedation. Results were analysed statistically, and receiver operating characteristic (ROC) curves were generated in order to evaluate the diagnostic efficacy of RI. RESULTS: In all, 15 animals completed the study protocol. In the obstructed group, hydronephrosis and significant compromise of renal function developed on the subject side, whereas sham-operated pigs had stable renal morphology and function throughout the study. There were however no significant differences in RI or DeltaRI between the two groups at any age, or between right and left RIs in the obstructed group at any point. RI and DeltaRI had no prognostic or diagnostic value as judged by ROC curve analysis. CONCLUSIONS: RI and DeltaRI were not affected by partial unilateral ureteral obstruction induced in the immature neonatal porcine kidney. The results of this study do not support the clinical use of Doppler ultrasound studies in the diagnostic work up of congenital hydronephrosis.

Tolterodine treatment for children with symptoms of urinary urge incontinence suggestive of detrusor overactivity: results from 2 randomized, placebo controlled trials.

PURPOSE: We report the results of the first 2 large randomized controlled trials designed to evaluate the efficacy and safety of tolterodine extended release in children 5 to 10 years old with symptoms of urinary urge incontinence suggestive of detrusor overactivity. MATERIALS AND METHODS: Two double-blind, placebo controlled trials were conducted sequentially. Children 5 to 10 years old with incontinence suggestive of detrusor overactivity (1 or more diurnal incontinence episodes per 24 hours) were randomized to tolterodine (2 mg daily) or placebo for 12 weeks. The primary end point was the change from baseline to week 12 in the number of incontinence episodes per week. Changes from baseline in the number of voids per 24 hours and volume of urine per void were also evaluated. Exploratory analyses were conducted to determine whether particular subsets of patients showed differential responses to treatment. RESULTS: A total of 224 and 487 children (mean age 8 years) were randomized to placebo and tolterodine, respectively. Differences in the number of incontinence episodes per week, voids per 24 hours, and volume of urine per void between tolterodine and placebo did not reach statistical significance. This finding may be explained by a high placebo response and under dosage of tolterodine among children with greater body weight. Tolterodine was well tolerated. CONCLUSIONS: Analysis of the primary efficacy outcome did not reveal a statistically significant effect of treatment. However, secondary analyses demonstrated that tolterodine was well tolerated among 5 to 10-year-old children with diurnal incontinence. Exploratory analyses also showed that children weighing 35 kg or less with detrusor overactivity characterized by incontinence and/or frequent voiding benefited most from tolterodine treatment, suggesting that a weight adjusted dosing regimen may be required for optimal response among older and heavier children.

The pharmacokinetics of 400 microg of oral desmopressin in elderly patients with nocturia, and the correlation between the absorption of desmopressin and clinical effect.

OBJECTIVE: To investigate the pharmacokinetic profile of oral desmopressin in elderly patients with nocturia, and to analyse any possible correlation between the absorption and clinical effect. PATIENTS AND METHODS: In all, 32 patients were screened to determine the baseline number of nocturnal voids and the nocturia index; of these, 24 fulfilled the inclusion criteria and were enrolled for a pharmacokinetic evaluation of oral desmopressin 400 microg. A double-blind, randomized, placebo-controlled, crossover-effect evaluation period was then used to test the association between the absorption of desmopressin and pharmacodynamic effect. Serial plasma samples were collected for 8 h for a pharmacokinetic analysis of desmopressin. The pharmacodynamics after an equivalent oral dose before bedtime were assessed by measuring changes in the number of nocturnal voids, time to first nocturnal void and nocturnal diuresis, from placebo to active treatment. RESULTS: There was a linear relationship between plasma desmopressin at 2 h after dosing and the area under the plasma concentration curve from 0 to infinity (Pearson's rho 0.923, P < 0.001). Women had a significantly higher plasma desmopressin concentration than men (P = 0.0012) and more adverse events. There was no correlation between plasma desmopressin at 2 h after dosing and the within-patient response in any of the effect variables. Generally, the number of nocturnal voids and nocturnal diuresis were half that with placebo. The time to the first nocturnal void was almost doubled compared with placebo. CONCLUSIONS: There seems to be a relationship between gender, plasma level of desmopressin and the incidence of adverse events. Plasma desmopressin at 2 h after dosing cannot be used to predict the pharmacodynamic response, although desmopressin lowers the nocturnal diuresis and the number of nocturnal voids.

The circadian rhythm of urine production, and urinary vasopressin and prostaglandin E2 excretion in healthy children.

PURPOSE: In adults and adolescents the transition from day to night is followed by a pronounced decrease in diuresis, as well as reduction in the amount of osmotically active substances excreted. We investigate the circadian variations in urine production in healthy children 3 to 14 years old. MATERIALS AND METHODS: A total of 92 children completed urine collections in 2 consecutive days to be analyzed for electrolytes, urea, creatinine, osmolality, vasopressin and prostaglandin E2. RESULTS: We found a marked reduction in urine output during the night (43.41 +/- 18.53 to 25.69 +/- 12.71 ml per hour) accompanied by a decrease in the amount of electrolytes excreted (sodium 4.44 +/- 2.09 to 2.66 +/- 1.55 mmol per hour and potassium 2.38 +/-0.96 to 0.90 +/- 0.54 mmol per hour). Age and gender did not influence the observed circadian rhythm in the quantity and quality of urine production. Urinary excretion of vasopressin did not seem to reflect the circadian variations previously described for the plasma levels of the hormone. Prostaglandin E2 showed a clear circadian variation with a 30% decrease at night (32.2 +/- 19.0 to 22.0 +/- 12.6 ng/mmol creatinine). CONCLUSIONS: Healthy children exhibit pronounced circadian variations in the amount and composition of urine output with a decrease in nocturnal diuresis and excretion of osmotically active solutes. In the age range of 3 to 14 years neither age nor gender seems to affect this rhythm. Vasopressin-to-prostaglandin E2 excretion ratio appears to be of importance for regulation of urine production.

The outcome of detrusor myotomy in children with neurogenic bladder dysfunction.

PURPOSE: We evaluate the outcome of detrusor myotomy for neurogenic bladder dysfunction (NBD) in children. MATERIALS AND METHODS: A retrospective analysis was performed of data compiled from medical and urodynamic records of children younger than 16 years with NBD who had undergone detrusor myotomy from 1992 to 2000 at our department. RESULTS: Surgery was performed in 14 children with a mean age +/- SD of 6.7 +/- 4.3 years (range 0.9 to 14.2) and mean followup of 5.9 +/- 1.7 years. All patients were diagnosed with NBD, which was the result of myelomeningocele in 9, sacral agenesis in 2, lumbosacral lipoma in 1, multiple vertebral anomalies in 1 and spinal neuroblastoma in 1. Main indications for surgery included urinary incontinence in 11 cases and high pressure/low capacity bladders with vesicoureteral reflux and impending renal damage in 8. No major postoperative complications were recorded. Although mean maximal cystometric bladder capacity was unchanged 1 month postoperatively (89.7 +/- 70.6 ml) compared to preoperatively (92.5 +/- 75.1 ml, p = 0.87), significant increments of 216%, 237% and 292% were measurable at 3 months, 1 year and 5 years, respectively. Ultimately most of the patients approached age specific capacities. Complete continence on clean intermittent catheterization was achieved by 8 of 11 patients and improved markedly in 1. Reflux was alleviated in 6 cases and improved in 1. Kidney function developed normally in all but 1 patient with persistent reflux. CONCLUSIONS: When feasible, detrusor myotomy offers a safe and effective alternative for the management of pharmacologically intractable NBD in children.

Resistive index: an experimental study of acute complete unilateral ureteral obstruction.

RATIONALE AND OBJECTIVES: To study the effects of acute complete unilateral ureteral obstruction (UUO) and release on porcine renal resistive index (RI). METHODS: Under general anesthesia, UUO was induced in six pigs. RI was measured bilaterally at predetermined intervals for 4 hours of UUO and 1 hour of release. Additionally, measures of renal blood flow (RBF), glomerular filtration rate (GFR), arterial blood pressure, renal vascular resistance (RVR), and ipsilateral renal intrapelvic pressure (IPP) were obtained. RESULTS: UUO and resultant progressive IPP increase caused prompt and significant ipsilateral RI elevation, and contralateral RI decrease. Concomitantly, ipsilateral RVR increased significantly while RBF and GFR declined, both significantly. Release of obstruction saw an almost immediate normalization of ipsilateral RI, RVR and RBF while ipsilateral GFR assumed 80% of baseline value 15 minutes postobstruction. Throughout the experiment, ipsilateral RI correlated significantly with changes in IPP, GFR, RBF, and RVR with correlation coefficients of 0.844, -0.851, -0.898, and 0.836 respectively ( < 0.001). CONCLUSIONS: UUO causes a divergent RI response that is instantly reversed upon release. IPP seems to be the principal effector of these changes in the early phases of UUO.