Renal involvement in children with vesicoureteral reflux: are prenatal detection and surgical approaches preventive?

Objective. Surgical correction of vesicoureteral reflux (VUR) and prolonged administration of antibiotics seem to lead to similar renal outcomes. However, it is not known whether prenatal recognition and the position of VUR modify the outcome in different ways. The purpose of this study was to investigate the effects of prenatal detection and different treatment methods on the outcome of unilateral refluxing renal units. Patients and methods. This retrospective study enrolled 119 children (mean age 2.8+/-3.5 years) with primary VUR. Kidney growth and renal function were measured with ultrasound and scintigraphy, respectively. To compare the ultrasound readings among patients of different ages the comparative-length index or index was calculated, as a percentage of the ratio of unilateral and the sum of bilateral renal length. Results. In unilateral refluxing renal units there was a reduction in both index and function, whereas not-refluxing was increased. In the follow-up, unilateral refluxing renal units had a worse index, whereas not-refluxing was better. Unexpectedly, surgical therapy of the left-refluxing renal unit led to a reduction in the index, whereas its function always stayed low in diagnosis but stable. The outcome of severely refluxing renal units was similar after both interventions. Prenatal and postnatal diagnosis did not seem to modify the renal result. Conclusions. Surgery showed similar renal outcomes to medical treatment. A kidney growth defect from high-grade VUR was detected in the diagnosis. Therefore, a congenitally damaged kidney does not ameliorate after each treatment. Finally, prenatal detection of VUR does not seem to modify the outcome of the kidney significantly.     

Screening for vesicoureteral reflux and renal scars in siblings of children with known reflux

The incidence of vesicoureteral reflux (VUR) in the general population is less than 1%, but it is high in families with reflux. The reported prevalence of VUR among siblings of index patients with reflux has ranged from 4.7% to 51%. Reflux carries an increased risk of pyelonephritis and long-term renal impairment. The purpose of this study was to identify the age-related incidence and severity of reflux, and the frequency of associated renal parenchymal damage in siblings of children with reflux in order to assess the use of screening at different ages. Between October 1994 and February 2003, 40 siblings of 34 index patients were screened with direct voiding cystography. 99( m ) technetium (Tc)-dimercaptosuccinic acid (DMSA) nuclear renal scans were performed in siblings with VUR to detect renal scarring. The cystograms were interpreted as showing the presence or absence of VUR and the DMSA scan as symmetrical or asymmetrical differential function, with or without renal scarring. Of 40 siblings, 17 had VUR, representing an incidence of 42.5%. The mean age at study entry of the 15 boys and 25 girls was 63 months (range 6 months to 12 years). The majority of siblings with abnormal DMSA scans were asymptomatic. Reflux was unilateral in 12 siblings and bilateral in 5. Of the 17 refluxing siblings (22 refluxing ureters), 7 (41.17%) had a history of symptomatic urinary tract infection (UTI). The frequency of VUR was nearly equal in siblings over 6 years and those younger than 6 years. Of the 17 siblings with VUR, 16 had DMSA scintigraphy. Of these, 5 were normal and 11 (68.75%) showed abnormalities (7 asymmetrical differential function and 4 parenchymal defect), which was bilateral in 7 and unilateral in 4. In conclusion, this study confirms a significant overall incidence of VUR and renal parenchymal damage in the siblings of patients with known reflux. The prevalence of reflux in older siblings is similar to that in younger siblings. Our review suggests that all siblings over 6 years should undergo a screening cystogram, even in the absence of urinary tract infection. DMSA scintigraphy of asymptomatic siblings appears to be beneficial in preventing renal injury.     

Split renal function does not change after successful treatment in children with primary vesico-ureteric reflux

OBJECTIVE: To evaluate the renal growth pattern in patients with primary vesico-ureteric reflux (VUR) using long-term measurements of split renal function with 99mTc-dimercaptosuccinic acid (DMSA) scintigraphy. PATIENTS AND METHODS: In all, 712 children aged < 16 years (466 boys and 246 girls) with primary VUR were referred to our hospital from July 1991 to December 2000. VUR was diagnosed by voiding cysto-urethrography. The patients were treated either surgically (group 1) or conservatively (group 2) and followed with serial 99mTc-DMSA scintigraphy for up to 10 years. There were 942 examinations in 367 of 712 patients who had repeat scintigraphy. Patients with secondary VUR, VUR to a solitary or fused kidney, or upper urinary tract obstruction, were excluded. Five of 298 patients (1.7%) who had ureteric reimplantation had a febrile urinary tract infection (UTI) soon after surgery but none recurred (recurrence is an indication for surgery in children with VUR); there was no febrile UTI in the 69 patients in group 2. Planar scintigraphy with 99mTc-DMSA was used to assess the absolute uptake (AU) of each kidney, measured as a percentage of the injected dose, and the relative uptake (RU = AU of each kidney/AU of both kidneys) calculated. The initial examination was at least 4 weeks after any febrile UTI in most patients. Serial studies were conducted 1 year after surgery and then biannually in group 1. In group 2 the DMSA scan was repeated every 2-3 years. The change in split renal function was compared with the RU of the right kidney. RESULTS: The RU of the right kidney at the initial scan correlated closely with those on repeated scans in both groups. The correlation coefficients were 0.99 in group 1 and 0.94-0.97 in group 2 at every study. The change of RU remained within 0.05 in all patients after treatment. CONCLUSIONS: Under strict control of UTI, split renal function in children with primary VUR does not change. There may be no possibility of accelerated or compensatory growth of the kidney with reflux nephropathy, but no concern about deterioration and atrophy either.     

Effects of vesicoureteric reflux on renal growth and function as measured by GFR, plasma creatinine and urinary concentrating ability. An experimental study in the minipig

The influence of vesicoureteric reflux (VUR) on renal growth and function measured by glomerular filtration rate (GFR), plasma creatinine concentration and urinary concentrating ability has been examined in a simple one-kidney model in the growing minipig over a period of approximately 5 months. Animals with reflux in association with low voiding pressures and normal bladder function (n = 6), as well as those with raised voiding pressures and abnormal bladder function (n = 5), were investigated together with appropriate non-refluxing controls (n = 12). Urinary infection and renal scarring were avoided since these factors may affect kidney function and growth independently. Statistical tests of difference failed to demonstrate any effect of VUR on 51Cr EDTA GFR or renal growth even in the presence of elevated voiding pressures and abnormal detrusor function. However, a significant association between VUR and reduced urinary concentrating ability was shown.     

Outcome of conservative treatment of primary vesicoureteral reflux in 87 Thai children in a single center

AIM: To evaluate the outcome of primary vesicoureteral reflux (VUR) using conservative treatment. METHODS: Eighty-seven children with primary VUR who had been treated with a conservative medical regimen and monitored through a yearly cystogram were recruited for the study. The study was conducted at the Pediatric Nephrology Clinic in Songklanagarind Hospital, the major tertiary care center in southern Thailand. Statistical analyses using Kaplan-Meier survival curves, chi-squared test, Fisher's exact test and multivariate analysis with Cox regression were performed. RESULTS: The study group consisted of 41 boys and 46 girls, with a total of 133 VUR. The age of the boys was significantly lower than that of the girls (P < 0.001). Resolution of the low grades (grades I-III) of VUR was significantly more frequent than that of the high grades (grades IV-V) (68/95, 72%vs 14/38, 37%; P < 0.001). Using the Kaplan-Meier survival analysis and log-rank test, the resolutions of VUR in boys versus girls, and age <1 years versus >or=1 years were not significantly different (P = 0.2252 and 0.4756, respectively). Low-grade VUR and unilateral VUR had significantly higher probabilities of resolution than high-grade VUR and bilateral VUR, respectively (P = 0.0041 and 0.0467, respectively). Multivariate Cox regression analysis indicated that among low-grade VUR, boys and unilateral VUR had significantly higher probabilities of resolution. Among the high-grade VUR, neither sex nor laterality had a significant effect on the probabilities of VUR resolution. CONCLUSION: This study offers more evidence that children with low-grade VUR have a higher chance of reflux resolution if they are boys and have only unilateral VUR. There is still no good guide for resolution of reflux in children with high-grade VUR.     

Primary vesicoureteral reflux mediated renal scarring after urinary tract infection in Thai children

AIM: To evaluate the association between primary vesicoureteral reflux (VUR) and renal scarring in children using 99 m Technetium-labelled dimercaptosuccinic acid (DMSA). METHODS: Children attending at Songklanagarind Hospital from 1987 to 2002 were evaluated. RESULTS: Ages at diagnosis of VUR in 46 boys and 52 girls were 1.1+/-1.6 and 2.9+/-2.5 years, median 0.6 and 2.3 years, respectively (P<0.001). DMSA scans were performed at 4.1+/-3.6 years. Renal parenchymal damage was detected in 34 kidneys (22%) of 154 demonstrated refluxing ureters, and one kidney (2%) of 42 non-refluxing ureters (P=0.002). Of 79 refluxing ureters in boys and 75 refluxing ureters in girls, there were 25 and nine renal scars, respectively (32% and 12%, P=0.003). Renal scars in VUR grades I-V were 11%, 7%, 12%, 44% and 64%, respectively (P<0.001). Multivariate analysis revealed that high grade VUR (P<0.001), age of diagnosis of VUR greater than 5 years (P=0.001), and male gender (P=0.002) were the most significant risk factors for renal scarring. CONCLUSION: High-grade VUR, age of diagnosis of VUR greater than 5 years and male gender were the most significant risk factors for renal scarring.     

Quo vadis? Ureteric reimplantation or ignoring reflux during augmentation cystoplasty

OBJECTIVE: To decide whether antireflux surgery should be used in the presence of vesico-ureteric reflux (VUR) in children, in whom an augmentation procedure is needed, because secondary VUR in children with a neurogenic bladder, infravesical obstruction and primary VUR in the exstrophy-epispadias complex is expected to resolve after augmentation, which decreases the intravesical pressure and increases capacity. PATIENTS AND METHODS: Between 1987 and 2001, the bladder was augmented in 38 children, using no antireflux surgery in group 1 (15 patients) and antireflux surgery in group 2 (23 patients). RESULTS: VUR was detected in all patients on cysto-urethrography before surgery; reflux resolved after augmentation cystoplasty in 97% and 93% of refluxing units in groups 1 and 2, respectively. The increase in the expected bladder capacity was from 35% to 86% in group 1 and from 38% to 90% in group 2. No patient had any deterioration in renal function. CONCLUSIONS: We recommend using only augmentation in patients with low- or high-grade VUR and a neurogenic bladder, infravesical obstruction and exstrophy-epispadias. Combining antireflux surgery with cystoplasty has no significant effect on either the resolution of VUR or renal function.     

The Efficacy of Tc99m Dimercaptosuccinic Acid (Tc-DMSA) Scintigraphy and Ultrasonography in Detecting Renal Scars in Children with Primary Vesicoureteral Reflux (VUR)

Introduction: Pyelonephritis-induced renal scarring in children is a major predisposing factor for proteinuria, hypertension, and ultimate renal failure. The aim of this study was to investigate and compare the efficacy of Tc99m dimercaptosuccinic acid (Tc-DMSA) renal scintigraphy and renal ultrasonography (USG) in detecting renal scars in children with primary vesicoureteral reflux (VUR). Materials and methods: Tc-DMSA scan and USG studies were done in 62 children who were admitted to our clinic between 1997 and 2003 because of documented urinary tract infection (UTI) and diagnosed with primary VUR. Renal scarring detection rates of Tc-DMSA scan and USG were compared according to reflux grades. Results: In the whole group, renal scars were detected by Tc-DMSA scan and USG in 55% and 38% of refluxing units, respectively. Detection rates of Tc-DMSA and USG according to reflux grades were as follows: 47% and 29 % in low-grade VUR (grades 1 and 2), 46 % and 25% in mid-grade VUR (grade 3), 76% and 65% in high-grade VUR (grades 4 and 5), respectively. Conclusion: USG was found to be an inappropriate study in the detection of renal parenchymal scars, irrespective of the reflux grade. In this study, Tc-DMSA scan detected scars in 35% of kidneys reported to be normal on USG.     

Urinary Tamm-Horsfall protein excretion in patients with primary vesicoureteral reflux

The excretion of urinary Tamm-Horsefall protein (THP) was determined by enzyme-linked immunosorbent assay and glomerular filtration rate (GFR) was calculated with technetium-99m diethylenetriamine pentacetic acid (99mTc-DTPA) renal scintigraphy in 26 consecutive patients with primary vesicoureteral reflux (VUR) before and after antireflux surgery. Wide variations of urinary THP excretion and GFR were seen in all grades of VUR. On the basis of the relationship between urinary THP excretion and GFR before the surgery, patients were divided into three groups. The first group (group A, n = 8) had normal urinary THP values and normal values of GFR. The second group (group B, n = 11) had high THP excretion and moderately decreased GFR, the third group (group C, n = 7) had normal urinary THP excretion and severely decreased GFR. In group A, urinary THP values remained normal and GFR improved in all patients after surgery. In group B, GFR improved when urinary THP dropped immediately, but GFR did not improve when urinary THP remained high after surgery. In group C, GFR did not improve and urinary THP continued to be low or tended to drop again after the surgery. The results suggested that serial measurements of urinary THP excretion and GFR by 99mTc-DTPA renal scintigraphy before and after antireflux surgery are useful for the evaluation of renal function in patients with primary VUR.     

Is ACE gene polymorphism a risk factor for renal scarring with low-grade reflux?

The possible relationship between the angiotensin-converting enzyme (ACE) gene insertion/deletion (I/D) polymorphism and renal scarring secondary to vesicoureteral reflux (VUR) has recently attracted attention and the DD genotype was postulated to be a risk factor for renal scarring. However, available data represent conflicting results. The aim of this study was to investigate the ACE gene I/D polymorphism and the other known risk factors for renal scarring in children with low- and high-grade VUR. The study included 96 (67 females, 29 males) patients (mean age at diagnosis 3.7±3.3 years) with VUR that were assessed for ACE I/D gene polymorphism. ACE genotypes were determined as II, ID, and DD using the polymerase chain reaction. The control group consisted of 103 healthy children with the same ethnicity to find the distribution of ACE gene I/D polymorphism in the population. The frequency of renal scarring was 80.8% in the high-grade reflux group and 34.3% in the low-grade reflux group. There was no difference between groups with renal scarring and without scarring with respect to gender, family history of VUR, age at diagnosis of VUR, associated urological abnormalities, frequency of urinary tract infection episodes, and the occurrence of bilateral or unilateral VUR. Genotype DD was found to be a significant risk factor for renal scarring in the study group by multivariate regression analysis (odds ratio 3.79, P=0.011). It was not a risk factor in high-grade reflux patients (odds ratio 0.60, P=0.62). However, it was a risk factor in low-grade patients with respect to renal scarring (odds ratio 4.0, P=0.024). Although renal scarring is not common in low-grade reflux patients, there may be scarring in some patients. DD polymorphism of the ACE gene is a significant risk factor in low-grade reflux patients with renal scarring.     

Reflux nephropathy secondary to intrauterine vesicoureteric reflux

In 107 infants with 182 antenatally diagnosed urinary tract anomalies, 24 had either unilateral (12) or bilateral (12) vesicoureteric reflux (VUR). The VUR was more common in boys (male to female ratio, 16:8) and usually severe (grades IV [16], III [10], II [4], and I [6]). Intravenous pyelography showed the changes of atrophic pyelonephritis in 10 refluxing units, and in another two with an associated pelviureteric junctional hydronephrosis. Lateral ectopia of the ureteric orifices was noted in six of these 10 refluxing renal units. Isotopic renography showed a reduction in function in nine of the 14 patients examined, ranging between 9% and 41%. (45% and above was considered within the normal range). Only two patients developed a urinary infection before intravenous pyelography or isotopic renography was performed, suggesting that renal changes noted were primary rather than secondary. Findings support the hypothesis that foetal VUR may be a contributing factor in the causation of atrophic pyelonephritis (foetal reflux nephropathy) observed in these patients.     

Scintigraphic screening for renal damage in siblings of children with symptomatic primary vesico-ureteric reflux

OBJECTIVE: To define prospectively the incidence of renal parenchymal lesions in the siblings of patients treated at one institution for primary vesico-ureteric reflux (VUR). PATIENTS AND METHODS: From January 1997 to October 1998, a prospective study including renal scintigraphy (using dimercaptosuccinic acid, DMSA) and a radionuclide cystogram was proposed systematically to the asymptomatic siblings of children treated for primary VUR. The radionuclide cystograms were interpreted as showing the presence or absence of VUR and the DMSA scan as symmetrical or asymmetrical differential function, with or with no renal defect. RESULTS: Fifty-five families gave informed consent, of whom 46 completed the study (eight refused secondarily and one was omitted by exclusion criteria), representing 46 symptomatic patients and 65 siblings. There were 17 siblings with VUR (26%) including two of 13 infants and 15 of 52 children aged > 18 months. One radionuclide cystogram failed. Of the 17 refluxing siblings, four had a history of symptomatic urinary tract infection; 62 of the 65 siblings had a DMSA scan, of which 56 were normal and six (10%) showed abnormalities (five asymmetrical differential function and one parenchymal defect). Only one of these six patients had VUR at the time of the evaluation and only one had a small kidney detected by ultrasonography on one side (and no VUR). There were no adverse effects associated with screening. CONCLUSION: This study confirms a significant overall incidence of VUR (26%) in the asymptomatic siblings of patients treated for primary VUR. From the results of the DMSA scan (only one sibling had a parenchymal defect), the systematic screening of asymptomatic siblings does not appear to be beneficial.     

Outcome of kidneys in patients treated for vesicoureteral reflux (VUR) during childhood.

BACKGROUND: Outcome of renal function and blood pressure (BP) at early middle age was clarified in patients treated for vesicoureteral reflux (VUR) during childhood. METHODS: Information of renal function was available from 147 (55%) of 267 patients treated for non-obstructive VUR of any grade. Twelve patients had died of kidney-related conditions and eight had gone into terminal uraemia. A total of 127 patients participated in the study. RESULTS: The mean age of the participants was 41 years. No signs of renal scars were detected by ultrasound examination in 53 (42%) subjects. Unilateral scarring was seen in 44 (35%) and bilateral in 30 (24%) subjects. Glomerular filtration rate (GFR) showed moderate or severe renal insufficiency in four (3%) participants, all with bilateral scars. Normal GFR was found in one-third of the patients. Twenty-five (83%) subjects with bilateral scars and 60 (62%) of the other participants had abnormal GFR values (P < 0.05). Proteinuria was found in 12 (9%) and albuminuria in 30 (24%) participants. Hypertension was diagnosed earlier in 14 (11%) patients, eight having bilateral scarring (P < 0.01). Diastolic BP was significantly lower in subjects without scars compared with those having scars in one or both kidneys (P < 0.05). CONCLUSIONS: Renal function was slightly lowered in more than half of the participants. Findings of the participants with unilateral scarring or unscarred kidneys were similar, except for the increased tendency for hypertension in subjects with scars. A total of 83% of the patients with bilateral kidney scars had lowered kidney function, a quarter presented with proteinuria and a half with hypertension. Long-term follow-up for all the patients with earlier VUR is emphasized.     

Urinary diversion in infants with primary high-grade vesicoureteric reflux, urinary sepsis and renal function impairment

INTRODUCTION: General consensus on the optimal treatment of septic infants with primary high-grade vesicoureteric reflux (VUR) and renal function impairment has not been reached. Our study aims at evaluating the role of temporary urinary diversion. MATERIALS AND METHODS: Twenty male infants, affected by sepsis and primary high-grade VUR, underwent urinary diversion in 1996-2001 because of estimated risk of renal function deterioration, due to non-compliance with the antibiotic treatment. Plasmatic creatinine clearance, ultrasonography, micturition cystography and scintigraphy were evaluated. RESULTS: Creatinine clearance was abnormal in 13 infants on admission, in 10 after urinary diversion and in 6 after second surgery. Renal damage (focal or diffuse) was evident in 16 patients, without modifications after surgery. No patient developed urinary tract infections (UTI). Vesicostomy was done in 12 cases, ureterostomy in 8. Nephrectomy was performed in 3 cases with poor renal function, and ureteroneocystostomy in 17. CONCLUSIONS: Urinary diversion in septic infants with high-grade VUR can represent an alternative approach to the conservative or surgical treatment in selected patients presenting risk of renal function impairment. This procedure allowed an easy management of UTI without worsening of renal function while waiting for a better anatomical status to perform reconstructive surgery.     

Use of collagen for endoscopic correction in complicated vesicoureteral reflux

OBJECTIVE: Endoscopic treatment of children with primary vesicoureteral reflux (VUR) has become an alternative to long-term antibiotic prophylaxis and open surgery. The purpose of this study was to assess the efficiency and safety of endoscopic subureteral injections of collagen (STING) as a treatment for complicated VUR in children. MATERIAL AND METHODS: Twenty-five patients (41 ureteral units) underwent a modified STING procedure for the correction of complicated VUR. Of these patients, five (nine refluxing units) had Hutch's diverticulum, 10 (17 refluxing units) had a duplex system, eight (10 refluxing units) had ureterocele, one (three refluxing units) had a unilateral triple ureter and one (two refluxing units) had a bilateral single ectopic ureter. Of these 41 ureteral units, 14 had grade III VUR, 17 grade IV and 10 grade V. Fourteen refluxing units (30%) received one session of STING, which was successful, and 27 (70%) needed a second session. A follow-up voiding cystourethrogram was performed 3 months after each session of STING. RESULTS: The mean follow-up period was 24 months (range 3-36 months). Of these 41 refluxing units, 34 were treated successfully and regression or downgrading occurred in seven. Follow-up i.v. pyelography or sonography did not reveal any urinary tract obstruction. CONCLUSIONS: The results of this study showed that endoscopic correction of these complicated refluxing ureters may be the first choice of treatment, but the technique must be modified to suit each individual case.     

Predictive value of clinical and laboratory variables for vesicoureteral reflux in children

We aimed to determine the predictability of clinical and laboratory variables for vesicoureteral reflux (VUR) in children with urinary tract infection (UTI). Data of children with febrile UTI who underwent voiding cystoureterography between 2002 and 2005 were evaluated retrospectively for clinical (age, gender, fever ≥38.5°C, recurrent UTI), laboratory [leukocytosis, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), pyuria, serum creatinine (S_Cr)] and imaging (renal ultrasonography) variables. Children with VUR (group 1) vs. no VUR (group 2) and children with high-grade (III–V) VUR (group 3) vs. no or low-grade (I–II) VUR (group 4) were compared. Among 88 patients (24 male), 38 had VUR and 21 high-grade VUR. Fever ≥38.5°C was associated with VUR [odds ratio (OR): 7.5]. CRP level of 50 mg/l was the best cut-off level for predicting high-grade VUR (OR 15.5; discriminative ability 0.89 ± 0.05). Performing voiding cystourethrography based on this CRP level would result in failure to notice 9% of patients with high-grade VUR, whereas 69% of children with no/low-grade VUR would be spared from this invasive test. In conclusion, fever ≥38°C and CRP >50 mg/l seem to be potentially useful clinical predictors of VUR and high-grade VUR, respectively, in pediatric patients with UTI. Further validation of these findings could limit unnecessary voiding cystourethrography.     

Does pre-transplantation antireflux surgery eliminate post-renal transplantation pyelonephritis in children?

PURPOSE: Antireflux surgery for VUR before renal transplantation decreases the risk of post-kidney transplant UTI in pediatric patients with primary vesicoureteral reflux. We studied the risk of post-kidney transplant UTI in patients with or without surgical correction of VUR before transplantation compared to patients without VUR. MATERIALS AND METHODS: We compared 12 patients who had VUR corrected before transplantation (group 1) to 17 patients with VUR who did not undergo antireflux surgery before transplantation (group 2) and 36 patients undergoing renal transplantation without VUR (group 3). A total of 10 patients in group 1 (83.3%) and 10 in group 2 (58.8%) had high grade VUR. RESULTS: Eight patients in group 1 (66.7%), 6 in group 2 (35.3%) and 33 in group 3 (91.7%) remained free of febrile UTI during followup (p = 0.00). Among patients with high grade VUR 6 in group 1 and 1 in group 2 remained UTI-free (p = 0.02). A total of 33 patients in the control group (91.7%) remained free of febrile UTI, an incidence that was significantly lower compared to group 1 (p = 0.03) and group 2 (p = 0.00). Of the patients with high grade VUR 3 in group 1 (30%) and 4 in group 2 (40%) experienced recurrent febrile UTIs (p = 0.64). CONCLUSIONS: Even after surgical correction of VUR before transplantation the frequency of febrile UTI remained higher than that in kidney transplant recipients without VUR. In cases of high grade VUR reimplantation before renal transplantation decreased the rate of febrile UTI but it was still higher than the level of risk in the control group.     

Effect of ureteral reimplantation on prevention of urinary tract infection and renal growth in infants with primary vesicoureteral reflux

AIM: We retrospectively reviewed the results of ureteral reimplantation in infants with primary vesicoureteral reflux (VUR) to evaluate the effect on prevention of urinary tract infection (UTI) and renal growth. MATERIALS AND METHODS: From July 1991 to December 2001, a total of 205 infants (180 boys and 25 girls) with primary VUR underwent ureteral reimplantation at the Department of Urology, Osaka Medical Center and Research Institute for Maternal and Child Health, Osaka, Japan. Indications for surgery were high-grade reflux (grade IV-V), breakthrough UTI and non-compliance of medical treatment. Age at surgery raged from 1 to 11 months (mean, 6.4 months). Ureteral reimplantation was performed according to Cohen's method. Only two of 336 refluxing ureters required ureteral tailoring. Follow-up ranged from 12 to 110 months (mean, 64 months). Surgical outcome, frequency of UTI and individual renal growth measured by (99m)Tc-dimercaptosuccinic acid (DMSA) scintigraphy was evaluated. RESULTS: Postoperative ultrasound and voiding cystourethrography showed neither residual reflux nor ureterovesical obstruction. Contralateral low grade reflux occurred in six of 74 patients (8.1%) who had unilateral reflux preoperatively. After reimplantation, 10 patients documented 13 febrile UTI. Eleven of the 13 episodes occurred early in the postoperative period (<6 months). Frequency of febrile UTI reduced from 0.23538 before surgery to 0.00894 and 0.00081 per patient per month at 6 and 12 months after surgery, respectively. No development of renal scarring was seen in postoperative DMSA scan. Changes of differential renal function was <0.05 in all patients. CONCLUSION: The present results show ureteral reimplantation in infants is safe and very effective for the prevention of UTI. After surgical treatment in infancy, individual renal growth of children with primary VUR is stable.     

Posterior urethral valves: prognostic factors

OBJECTIVE: To determine which variables besides bladder dysfunction can help to predict the outcome of renal function in boys with posterior urethral valves (PUV). PATIENTS AND METHODS: All 40 patients with PUV in this retrospective study were diagnosed and began treatment in our hospital within the first 3 months of life, and have had >or= 5 years of follow-up. At the time of diagnosis, 33 were in renal insufficiency (RI) and seven had normal renal function (RF). At the time of the study 16 were in chronic renal failure (CRF) and 24 had normal RF. We compared their RF (initial and during follow-up), vesico-ureteric reflux (VUR), urinary tract infection (UTI), proteinuria, hypertension, renal echogenicity, final patient age and initial management. RESULTS: The mean serum creatinine values before and after initial treatment were worse in boys who developed CRF than in those who did not (P = 0.08); the mean glomerular filtrate rate (GFR) at 1 year old was 52 mL/min/1.73 m2 in the former and 102 in the latter (P < 0.001). Proteinuria was present during the follow-up in 79% of patients in CRF and in only 17% of those with normal RF. All patients who developed CRF had echogenic renal changes while only 53% of the others had (P < 0.01). Other variables showed no statistically significant differences (VUR, UTI, hypertension and final patient age). Of 33 patients in RI at diagnosis, nine were treated by valve ablation and 24 by temporary pyelo-ureterostomy. The initial mean serum creatinine value was worse in the latter than in the former (20.8 vs 13.0 mg/L). However, at 1 year old the mean GFR was better in the latter than in the former (P < 0.05). These GFR differences persisted during the first years of life but had disappeared by the fifth. CONCLUSIONS: The most significant prognostic factor for the future development of CRF is the GFR at 1 year old. The onset of proteinuria during the follow-up is associated with a worse prognosis. Echogenic renal changes may help to identify those dysplastic kidneys that will develop RI. Neonatal boys in RI who underwent pyelo-ureterostomy had better RF during the first years of life than those who underwent valve ablation.     

Contralateral reflux after unilateral ureteral reimplantation--preexistent rather than new-onset reflux

PURPOSE: The authors studied the preoperative Technetium 99m-dimercaptosuccinic acid renal scan (DMSA) of patients undergoing unilateral vesicoureteral antireflux surgery to compare the amount of renal scarring between the refluxing and the contralateral renal units. They sought to determine whether postoperative contralateral vesicoureteral reflux was preexistent or new onset. METHODS: Sixty-eight patients who underwent unilateral vesicoureteral antireflux surgery and had preoperative DMSA and postoperative voiding cystourethrography (VCUG) examinations were studied. Preoperative DMSA results were analyzed to determine the amount of renal scarring in each kidney. RESULTS: Sixty-four (94.1%) ipsilateral refluxing renal units had renal scars. Of the 68 contralateral renal units, scars were noted in 28 (41.2%). The rate of nonscar was 4 of 68 (5.9%) in reflux kidneys, which was significantly lower than 40 of 64 (62.5%, excluding 4 with a history of resolved reflux) in nonreflux kidneys (P<.001). Of 40 contralateral nonscarred kidneys, 1 of 40 (2.5%) had subsequent reflux, which was significantly lower than 5 of 28 (17.9%) of scarred kidneys (P<.005). Six patients (8.8%) had contralateral reflux, and 1 of them had a history of resolved reflux. Of the 6 contralateral kidneys with severe scarring involving 3 poles or contracted, 4 of 6 (66.7%) had subsequent reflux. CONCLUSIONS: Scar in the contralateral kidney seen on DMSA scan seems to predict contralateral reflux after unilateral antireflux surgery. The contralateral reflux may be preexistent. Postoperative VCUG should be performed routinely for patients who have contralateral renal scars. In patients with a history of contralateral reflux or severe contralateral renal scar, simultaneous contralateral ureteral reimplantation should be considered.