Combined creatinine velocity and nadir creatinine: A reliable predictor of renal outcome in neonatally diagnosed posterior urethral valves.

INTRODUCTION: Nadir creatinine (lowest creatinine during the first year following diagnosis) is a recognised indicator of future chronic renal impairment (CRI) in posterior urethral valve (PUV) patients. We recently described "creatinine velocity" (Cvel), the rate of change of creatinine following initial bladder drainage, as a new early predictor of CRI in neonatally diagnosed PUV. Rising Cvel (>3 µmol/L/day) is associated with increased risk of CRI. OBJECTIVE: We studied these two prognostic indicators in combination, as a test for future CRI in neonatally diagnosed PUV patients. STUDY DESIGN: Medical records for patients treated by endoscopic valve ablation at our institution between 1993 and 2004 were reviewed. Simple linear regression was used to calculate Cvel. Creatinine velocity and nadir creatinine were considered predictive of future CRI if they were greater than 3 µmol/L/day or greater than 75 µmol/L (0.85 mg/dL), respectively. Chronic renal insufficiency was defined as CKD2 or higher. Outcomes in test groups were analysed by Fisher exact test. Statistical significance was defined as p < 0.05. RESULTS: Sixty-two patients were treated within the first 30 days of life and had sufficient data to calculate both Cvel and nadir creatinine. Mean follow-up was 9.4 years. Patients were grouped as having both risk factors (Group A), one risk factor (Group B), or neither risk factor (Group C). All four (100%) patients from Group A developed CRI, compared with 11 of 17 (64.7%) patients from Group B and three of 41 (7.3%) patients from Group C (p ≤ 0.0005). As a diagnostic test for future CRI, "presence of at least one risk factor" had a specificity of 86.4%, sensitivity of 83.3%, positive predictive value of 71.4%, and negative predictive value of 92.7%. Additional prognostic information was obtained by assigning a score from 1 to 3 for each prognostic indicator (Table). The sum of these scores gave a PUV Risk Score. No patient with a PUV Risk Score of 2 developed CRI, while all patients with a Score of 6 developed CRI. Incidence of CRI in patients with PUV Risk Scores of 3, 4, and 5 was 8.3%, 50%, and 63.6%, respectively (p ≤ 0.0005). CONCLUSION: Considered together, these prognostic indicators provide a powerful test for future CRI. Presence of at least one of these risk factors should be considered "at risk for CRI". Patients with neither risk factor are unlikely to develop CRI. Calculation of the PUV Risk Score provides an even more accurate prognosis.

Mitrofanoff for valve bladder syndrome: effect on urinary tract and renal function.

PURPOSE: Despite early diagnosis and valve ablation, progressive renal impairment develops in a significant proportion of boys born with posterior urethral valves. Bladder dysfunction is thought to have an important role in the etiology of this renal deterioration. We report the outcome of treating bladder dysfunction with clean intermittent catheterization and overnight drainage via a Mitrofanoff appendicovesicostomy with respect to upper tract imaging, urodynamic findings and renal function. MATERIALS AND METHODS: All patients were established on a clean intermittent catheterization program via the Mitrofanoff stoma, including 3 or 4 daytime catheterizations and overnight drainage with an indwelling catheter. We analyzed trends in serum creatinine, renal ultrasound appearance and urodynamic data. RESULTS: Mitrofanoff formation was performed in 24 patients with valve bladder syndrome. Median followup was 6.2 years. Hydronephrosis, quantified by combined anteroposterior diameter measurements of the renal pelvis, significantly improved with a mean combined anteroposterior diameter reduction of 14.2 mm (95% CI 7.6-20.9, p ≤ 0.001). Overall bladder dysfunction improved. Capacity was decreased in 9 of 12 patients (75%) initially compared with 12 of 21 (57%) after Mitrofanoff surgery (p = 0.457). Compliance was poor in 75% of patients initially vs 28.6% at followup (p = 0.014). Despite improvements in hydronephrosis and urodynamic parameters the mean estimated glomerular filtration rate deteriorated. End stage renal failure developed in 35% of cases during followup. CONCLUSIONS: Treatment of valve bladder with clean intermittent catheterization and overnight drainage via a Mitrofanoff stoma can achieve significant improvements in hydronephrosis and bladder dysfunction urodynamic parameters. However, it does not prevent renal deterioration.

Posterior urethral valves: creatinine velocity, a new early predictor of renal insufficiency.

AIM: Antenatal screening has led to early detection of posterior urethral valves (PUV). However, despite early intervention, a proportion of children will develop chronic renal insufficiency. We studied the trend of serum creatinine following urinary tract decompression during the neonatal period in infants as a possible predictor of chronic renal insufficiency. METHODS: Patients treated by endoscopic resection of posterior urethral valves between 1993 and 2004 were identified. From these, infants treated within the first 30 days of life were identified. Serum creatinine values taken within the first 5 days following initial drainage were recorded. A creatinine velocity for each patient was calculated by linear regression analysis. Creatinine was considered rising if velocity was >3 µmol/L/day, or falling if velocity was <-3 µmol/L/day. Chronic renal insufficiency was defined as CKD2 or higher. RESULTS: Sixty-four neonates had decompression of the urinary tract. Of these, 16 had rising creatinine despite drainage, 10 had a plateau in creatinine level, and 36 had falling creatinine following drainage. Insufficient data were available in two to calculate creatinine velocity. Progression to renal insufficiency was significantly higher in patients with an initial rise in creatinine (62.5%) than in those with plateau creatinine (40%) or falling creatinine (8.6%) (P ≤ 0.0005 by Fisher exact test). Mean follow-up was 9.2 years. CONCLUSIONS: Rising creatinine, even transiently, following urinary tract drainage in neonates with posterior urethral valves is significant and is a new and important indicator of long-term prognosis.

Endoscopic placement of double-J ureteric stents in children as a treatment for primary obstructive megaureter.

AIM: To determine the efficacy and potential complications of double-J ureteric stents in the treatment of persistent or progressive primary obstructive megaureter in pediatric patients within our institution. MATERIALS AND METHODS: A retrospective case-note review of all patients with double-J ureteric stents, between 1997 and 2004, was performed. In all, 38 stents were inserted in 31 patients aged between 2 months and 15 years of age. Complications and results of follow-up investigations and the need for follow-up investigations were recorded. Patients were followed up clinically and radiologically for a minimum of 2 years following stent insertion. RESULTS: Endoscopic placement of double-J ureteric stents in childhood is straightforward and complications are uncommon (8/38 insertions). In non-resolving or progressive primary non-refluxing megaureter, double-J ureteric stenting alone is effective with resolution of primary non-refluxing megaureter in 66% of cases (25/38 insertions). CONCLUSIONS: Ureteric stenting provides an alternative to early surgery in patients with primary non-refluxing megaureter. The youngest patient in our series was 2 months old at the time of endoscopic ureteric double-J stent insertion. Endoscopic placement of ureteric double-J stents should be considered as a first-line treatment in the management of persistent or progressive non-refluxing megaureter leading to progressive hydronephrosis or pyonephrosis.

Paediatric priapism--treatment conundrum.

Priapism is a rare condition in childhood. The majority of reported cases are boys with sickle cell disease, in whom nonoperative management may be successful when patients present early. We report a 14-year-old boy with sickle cell disease who presented with priapism of 72-h duration and was successfully treated by bilateral saphenocorporal shunts.

Neonatal prostatic rhabdomyosarcoma.

Rhabdomyosarcoma is one of the commonest soft tissue sarcomas of childhood, but neonatal presentation is extremely rare. This limited experience means there are no clear treatment guidelines in this age group. The authors report a boy with recurrent attacks of hematuria commencing in the neonatal period, which were shown to be from a prostatic rhabdomyosarcoma. To the best of our knowledge this is the first reported case of neonatal rhabdomyosarcoma in this site.

Bilateral multifocal renal oncocytoma.

Renal oncocytoma is a rare benign tumor. Bilateral and multifocal renal oncocytoma has rarely been described in childhood. We report a 12-year-old girl who presented with massive left renomegaly and who was found to have bilateral cystic kidneys. A left nephrectomy was undertaken because of the renal enlargement, the radiological evidence of extensive disease, and to make a diagnosis. A diagnosis of multifocal oncocytoma was made after detailed histological examination.