This Month in Pediatric Urology

Article Outline

• Longitudinal Development of Renal Damage and Function in Infants With High Grade Vesicoureteral Reflux
• Hypospadias Rates
• Body Mass Index as a Predictive Value for Complications Associated With Reconstructive Surgery
• Long-Term Followup Renal Scans in Children With Spina Bifida
• Copyright

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Longitudinal Development of Renal Damage and Function in Infants With High Grade Vesicoureteral Reflux 

Long-term followup of infants with high grade vesicoureteral reflux (VUR) is often lacking in many of the clinical reports describing observations and management of this select group of patients. Sjostrom et al (page 2277) from Gothenburg, Sweden provide new insights into the longitudinal development of renal damage and function, and risk factors for deterioration in infants with high grade VUR. The series includes 115 infants with grades III to V reflux (bilateral in 70%) which was diagnosed on an abnormal prenatal sonogram in 26% and after acute pyelonephritis in 71%. The proportion of infants with grade IV to V reflux was higher in the prenatally detected group (p=0.022). Renal abnormalities were classified as focal or generalized, and individual glomerular filtration rate (GFR) was calculated as a function of total GFR and split function on scintigraphy. All patients were maintained on antibiotic prophylaxis. Surgery was performed in 35 (30%) infants at a median age of 42 months. Total spontaneous resolution of VUR occurred in 31 cases and reflux grade decreased to II or less in 14. Median followup until the last scintigraphy and final GFR measurement was 62 and 53 months, respectively.

Renal functional abnormalities were seen at study entry in 98 of the 115 (85%) patients and at the end of followup in 103, of which 29 were bilateral. Isolated focal damage was seen in 30 cases, generalized damage in 65 and combined damage in 8. Subnormal GFR (less than 80% of expected for age) was noted in 34 patients, including 50% of those diagnosed prenatally vs 24% diagnosed after pyelonephritis (p=0.019). Renal status remained unchanged in 108 cases, improved in 5 and deteriorated in 19. Breakthrough febrile urinary tract infections (UTIs) were documented in 54 patients. The frequency and type of renal abnormality did not differ between patients with grades III and IV reflux. Predictive factors for deterioration were recurrent febrile UTI, bilateral abnormalities and reduced total GFR. Deterioration occurred more frequently in patients with a prenatal diagnosis than in those diagnosed after pyelonephritis. The authors conclude that renal function abnormalities in infants with high grade VUR are frequent with subnormal filtration of 1 kidney in almost 70% and subnormal total GFR in about a third. Deterioration of renal status was only seen in a fifth of the cases. Infection control seems to be an important factor to minimize this risk.

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Hypospadias Rates 

Recent focus on endocrine disruptors has led to speculation on their role in contributing to a decrease in sperm counts, increase in the incidence of testicular cancer and increase in the rate of genital abnormalities such as hypospadias. To investigate this potential relationship to hypospadias, Fisch et al (page 2291) from New York, New York analyzed the hypospadias rates from the New York State Congenital Malformations Registry from 1992 to 2005. The rates of children born to mothers younger than 35 years (group 1) and mothers 35 years old or older (group 2) were also analyzed. The registry only includes live births and 12,674 births were reported during the period analyzed. The authors found no statistical change in hypospadias rates in New York State (r=0.127, p=0.6). Overall, the mean ± SE prevalence rate was 34.9 ± 0.36/10,000 live births. This prevalence rate had not increased from that reported for 1983 to 1995. However, the mean hypospadias rate among children in group 2 (38.7± 0.7) was significantly higher than that of group 1 (34.1 ± 0.386). The authors conclude that their data strongly refute the claims for region-wide increases in hypospadias, noting a stable rate of hypospadias in New York State during a 22-year period. They further conclude that the alleged deleterious experimental effects on the rate of hypospadias reported in animal models exposed to high levels of endocrine disruptors may not be clinically evident in humans based on normal environmental exposure.

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Body Mass Index as a Predictive Value for Complications Associated With Reconstructive Surgery 

We are increasingly aware of the widespread deleterious impact on health care posed by the current epidemic of obesity in children and adults. As a group, patients with myelodysplasia are more prone to obesity secondary to the less active lifestyles and decreased energy requirements because they are non-ambulatory. Donovan et al (page 2272) from Oklahoma City, Oklahoma retrospectively investigated the relationship comparing body mass index (BMI) and surgical complications in a group of 66 myelodysplasia patients who underwent urinary or fecal reconstructive procedures between 1997 and 2005. Patient records were reviewed for any documented complication occurring during hospital admission (early) or followup (late). Median followup was 30 months. BMI was calculated by height and weight using the standard formula (BMI = kg/m²). BMI was characterized as normal (less than 85th percentile), overweight (between 85th and 95th percentile) or obese (greater than 95th percentile). Of the patients 30 were considered to be of normal weight, 10 were overweight and 20 were obese. A total of 51 complications occurred in 31 (51.7%) of patients. A significant association was observed between the occurrence of complication and weight category (40% of normal, 40% of overweight and 75% of obese patients; p = 0.373). Stomal stenosis complications occurred in 66% of the obese group and 10 of 15 patients with 2 or more complications were obese (p = 0.0066). The authors conclude that obesity in patients with myelodysplasia is associated with a higher surgical complication rate, and that aggressive weight loss programs should be recommended before and after any urinary or fecal reconstructive procedures.

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Long-Term Followup Renal Scans in Children With Spina Bifida 

Children with spina bifida are at significant risk for upper tract deterioration as a result of poor, noncompliant bladder management and a high incidence of UTI with or without associated vesicoureteral reflux. Dimercapto succinic acid (DMSA) renal scans are useful to confirm the diagnosis of acute pyelonephritis and detect renal parenchymal scarring in patients with neuropathic bladder, particularly those performing clean intermittent catheterization (CIC). Shiroyanagi et al (page 2262) from Yokohama, Japan investigated the relationship among an abnormal ^99mtechnetium DMSA scan, VUR and urodyanamic findings in 64 patients (mean age 15.8 years) with spina bifida during long-term followup (mean followup 14.6 years). All patients were treated with CIC with or without anticholinergic medications. Age, gender, previous febrile UTI, VUR history, timing of CIC initiation and the most recent urodynamic findings were compared between patients with (16 subjects) and without (48) an abnormal DMSA scan.

DMSA scan abnormalities were present in 16 of the 64 children, including 11 with previous febrile UTI vs 9 without a scan abnormality. A positive history of VUR was present in all cases with an abnormal DMSA scan vs 15 with a normal scan (p <0.01). There was no difference between groups for mean age, male-to-female ratio, timing of CIC initiation, detrusor leak point pressure or bladder compliance. Multivariate analysis confirmed previous febrile UTI as being significantly related to abnormal DMSA scan findings (p <0.01). VUR history was excluded from multivariate analysis because of the value of 0 in the VUR history data. The authors conclude that febrile UTI and history of VUR are highly significant factors associated with abnormal DMSA renal scans in children with spina bifida treated with CIC.