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.     

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.     

99m Technetium dimercapto-succinic acid renal scintigraphy abnormalities in infants with sterile high grade vesicoureteral reflux

PURPOSE: Although vesicoureteral reflux associated with bacteriuria may cause renal scarring, sterile reflux is thought not to cause renal injury. We determined the incidence and associated characteristics of renal abnormalities using 99mtechnetium(Tc) dimercapto-succinic acid (DMSA) renal scintigraphy in infants with high grade vesicoureteral reflux but no history of urinary tract infection. MATERIALS AND METHODS: We retrospectively reviewed the results of 99mTc-DMSA renal scintigraphy and renal ultrasonography performed during the first 6 months of life in infants with vesicoureteral reflux detected during the postnatal evaluation of prenatal hydronephrosis or sibling reflux screening. Those with a history of urinary tract infection, or evidence of ureteropelvic junction or bladder outlet obstruction were excluded from study. RESULTS: Of the 28 male and 6 female infants who met study criteria vesicoureteral reflux was bilateral in 25 and unilateral in 9. Reflux grade was IV or V, II or III and I in 38, 18 and 3 of the 59 refluxing renal units, respectively. 99mTc-DMSA renal scintigraphy revealed parenchymal abnormalities in 24 refluxing renal units (41%) in 22 patients (65%), of whom 19 (86%) were male and 15 (68%) had bilateral reflux. We noted differential uptake less than 40% with and without cortical defects in 10 and 7 refluxing units, respectively, and cortical defects only in 7. Of the 24 refluxing units with abnormalities 21 were associated with grade IV or V and 3 with grade II or III reflux. Ultrasound showed evidence of renal injury in only 7 of the 17 patients (41%) in whom 99mTc-DMSA scintigraphy was abnormal. CONCLUSIONS: In our study the majority of infants with high grade reflux had decreased differential function and/or cortical defects. Parenchymal defects detected by 99mTc-DMSA renal scintigraphy were often not identified by renal ultrasound. Therefore, 99mTc-DMSA renal scintigraphy is especially useful for initially evaluating infants with high grade, sterile vesicoureteral reflux.     

Utility of SPECT DMSA renal scanning in the evaluation of children with primary vesicoureteral reflux

OBJECTIVES: DMSA renal scanning is more sensitive than ultrasound in detecting renal parenchymal scars. We proposed to determine the utility of single-photon emission computed tomography (SPECT) dimercaptosuccinic acid (DMSA) renal scanning in children with primary vesicoureteral reflux (VUR). METHODS: During a 24-month period, we evaluated the charts of 368 patients who had undergone SPECT DMSA renal scanning for primary VUR. Patients were divided into three age groups: (a) less than 1 year, (b) between 1 and 5 years, and (c) older than 6 years. Renal scars were deemed severe or focal. The data were analyzed to evaluate the utility of SPECT DMSA scanning in children with primary VUR and to determine the indications for performing SPECT DMSA. We also evaluated the sensitivity of recent renal ultrasound technology in detecting focal and diffuse scars. RESULTS: One hundred twenty-eight patients were younger than 1 year at presentation. These included 24 cases that were detected prenatally. One hundred eighty-five were between the ages of 1 and 5 years, and 55 were 6 years or older. Reflux nephropathy at presentation was found in 99 (26.9%) of 368 patients. DMSA scanning changed the treatment in only 13 patients (3.5%). When scarring was diffuse, ultrasound examination correlated 100% with DMSA scanning; when focal scarring was present, the correlation was poor. CONCLUSIONS: Our results suggest that DMSA scans should be tailored to children who have ultrasound abnormalities, high-grade reflux, or recurrent breakthrough urinary tract infections. These guidelines will result in a substantial cost savings and a significant decrease in radiation exposure.     

Renal damage in vesico-ureteric reflux

OBJECTIVE: To detect the different extent of renal parenchymal involvement in primary vesico-ureteric reflux (VUR), and to evaluate the relationship between VUR grade, patient age and different patterns of parenchymal damage. PATIENTS AND METHODS: This blinded retrospective study included 197 consecutive children (mean age 4.26 years, range 1 month to 13 years) with primary VUR detected by voiding cysto-urethrography (VCUG), 99mTc-dimercaptosuccinic acid (DMSA; 120 MBq/1.73 m2) renal scintigraphy, with scanning for 3 h after intravenous injection. An abnormal DMSA scan was classified into three subtypes: cortical defects as a single scar (SS), multiple cortical scarring (MS) and diffuse reduced uptake with small renal size. Renal absolute uptake (AU), and split-kidney relative uptake were evaluated in refluxing and nonrefluxing renal units, and correlated with parenchymal damage and patient age. Student's t-test and the chi-square test were used for the statistical analysis. RESULTS: In all, 282 refluxing and 112 nonrefluxing units were assessed. Renal damage was detected in 188 of 282 units with VUR (67%) and in 18 of 112 (16%) contralateral nonrefluxing kidneys. The mean AU was 18.7% in kidneys with VUR and 29% in nonrefluxing units (P < 0.001). The mean (SD) AU decreased from lower to higher grades of VUR, i.e. grade 0 VUR (group A), 28.97 (9.71); grade 1-3 (group B), 21.28 (8.33); grade 4-5 (group C), 14.78 (8.02). The differences were statistically significant (A vs B, B vs C, both P < 0.001). Renal damage was differently distributed in the three groups: 69 of 109 kidneys (63%) in group C (MS prevalent), 39 of 173 (22.5%) in group B (SS prevalent) and 17 of 112 (15.2%) in group A. There was no significant difference in the distribution of renal damage subtypes in patients aged < or > 2 years (SS 19.6% vs 17.9%, MS 29.6% vs 30.1%, small size 48.2% vs 46.3%). The VUR was severe (group C) in 65% of patients aged < 2 years and in 46% aged > 2 years (chi-square, P = 0.016). CONCLUSIONS: VUR is commonly associated with renal damage. Age (< or > 2 years) did not significantly influence the kidney lesion subtype. Reduced parenchymal function (AU) progressively decreased with the severity of VUR. Focal MS, reduced size and relative uptake were significantly more common in severe VUR, leading to multifocal lesions and hypo-dysplasia. Renal scarring was present in up to 15% of contralateral nonrefluxing kidneys. Severe VUR behaved differently from lesser VUR in the renal scan parenchymal uptake.     

Evaluation of renal scarring in children with primary VUR by 99mTc-DMSA renoscintigraphy

Renal scarring in 271 kidneys of 172 children with primary vesicoureteral reflux (VUR) was evaluated by 99mTc-DMSA renoscintigraphy. 58% of refluxing kidneys were with renal scar by the initial DMSA renoscintigraphy. Only 52% of these kidneys showed good correlation between the findings on IVP and DMSA renoscintigram. Of the 144 refluxing kidneys with normal IVP, 41% had renal scarring on DMSA renoscintigram. DMSA renoscintigram revealed widespread renal scarring in 28% of kidneys with only calyceal clubbing and in 60% of those with segmental cortical thinning on IVP. It is realized that IVP was an in-sensitive method to evaluate renal scarring of refluxing kidneys and such kidneys with segmental renal scar on IVP accompanies more widespread scar on DMSA renoscintigram. These cases were allocated to 2 age groups, younger than 3 years and older than 4 years. In the former group less than 10% of kidneys with low grade VUR and about 40% with high grade UVR had widespread renal scarring. On the contrary, in the latter group severe renal scar was recognized in more than 20% of kidneys with low grade VUR and in about 60% with high grade UVR.     

Impact of early screening for reflux in siblings on the detection of renal damage

OBJECTIVE: To assess the impact of screening siblings after detecting significant vesico-ureteric reflux (VUR) and renal scarring, as such screening might identify patients with VUR before urinary tract infections develop, but might also detect clinically insignificant VUR. PATIENTS AND METHODS: We used a previously reported screening protocol to assess the clinical characteristics of patients, including the incidence of renal scarring, and their siblings, and compared the results. In all, 123 children were screened and 44 (36%) had VUR on voiding cystography. The median (range) age at screening was 9 (1-90) months. RESULTS: The grades of VUR detected were < III in 61% and > or = III in 39%; VUR was bilateral in 48%. In all, 37 siblings with VUR were assessed by ultrasonography; 70% were normal, including 12 (32%) children with VUR of grade > or = III. When used, renal scintigraphy was normal in 74% of siblings, vs 18% of index patients. However, when screened after 2 years old, siblings had twice the risk of already having renal damage on renal scintigraphy (P = 0.04). CONCLUSION: Early screening (< or = 2 years) appears to be more protective for avoiding renal damage than screening older patients. Thus we propose early screening in asymptomatic siblings to detect VUR before it becomes clinically significant.     

Management of vesicoureteral reflux in children

Background. Vesicoureteral reflux (VUR) in children has been reported in many studies. However, the management of VUR is still controversial. Methods. One hundred and fourteen children with primary VUR were divided into two treatment groups: medical (group A) and surgical (group B). The clinical courses and X-ray films of cystography and intravenous pyelography of these children were reviewed retrospectively, using the International Reflux Study Committee Classification. Results. In children less than 1 year of age, VUR was observed more frequently in boys. However, this ratio was reversed in children aged 2 years or more. Sixty-three percent of all refluxing ureters had reflux of grade III or higher at the initial examination. Spontaneous cessation of VUR was observed in 17% of group A ureters, and all had grade III or less reflux. Renal parenchymal scars were already present at the initial examination in 23% of kidneys with refluxing ureters. Recurrent urinary tract infections became less frequent after anti-reflux surgery. The progression of renal scars and renal growth retardation was observed more frequently in group B children. Conclusions. From these observations, it appeared that surgical management of VUR did not prevent the progression of renal scarring or renal growth retardation. Early detection of and intervention in VUR may prevent the progression of renal scarring and renal growth retardation. However, a multicenter, prospective, randomized controlled study would be necessary to confirm these findings. Received: October 4, 1999 / Accepted: January 15, 2000     

The etiology of renal scars in infants with pyelonephritis and vesicoureteral reflux

We aimed to investigate, by means of dimercaptosuccinic acid (DMSA) scan, the relations between vesicoureteral reflux (VUR) and its degree, pyelonephritis during infancy, and renal parenchymal findings. Seventy-four infants with pyelonephritis, 44 girls and 30 boys (mean age at their first pyelonephritic episode 4.12 months, median 3 months), were enrolled in the study. Voiding cystourethrography (VCU) and ultrasonography (US) were performed within 6 weeks following the infection. DMSA was performed at least 4 months after the urinary tract infection (UTI). The renal parenchymal pathology was defined as focal or multifocal defects or as a split renal uptake of less than 45%. DMSA scintigraphy revealed that 19% (14/74) of the children had renal damage. Renal parenchymal findings were observed only when VUR was present, and its grade was above 3/5. No abnormality was found in 51 renal units without reflux, 9 with VUR grade 1/5, and 54 with grade 2/5. Renal pathology was observed in 9/24 renal units with VUR grade 3, 3/8 with grade 4, and 2/2 with grade 5. No correlation was found between renal parenchymal defects and clinical presentation of the pyelonephritis, type of the microorganism, presence of bacteremia, or the number of recurrent infections. In adequately treated infants, renal damage is probably due to a reflux-associated, preexisting, congenital renal parenchymal pathology and not to the inflammatory process. We suggest that DMSA scintigraphy should not be performed routinely in every infant with UTI and should be reserved primarily for children with VUR grade 3 and above. Received: 17 February 1999 / Revised: 30 June 1999 / Accepted: 7 July 1999     

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.     

Renal scarring following reflux and nonreflux pyelonephritis in children: evaluation with 99mtechnetium-dimercaptosuccinic acid scintigraphy.

99mTechnetium dimercaptosuccinic acid (DMSA) scintigraphy is the imaging modality of choice for the detection of acute pyelonephritis and chronic renal scarring in children. Using the DMSA scan we prospectively evaluated renal scarring after reflux and nonreflux pyelonephritis in children. The study population consisted of 33 patients with acute pyelonephritis documented by a DMSA renal scan at infection. The children were evaluated for renal scarring with a followup DMSA scan 4 to 42 months (mean 10.7 months) after the acute infection. All new scarring on followup DMSA scans occurred at sites corresponding exactly to areas of acute inflammation on the initial DMSA scan. Therefore, only those kidneys with acute changes on the initial scan were subsequently analyzed. Of 38 kidneys new or progressive scarring developed in 16 (42%), including 6 of 15 (40%) with associated vesicoureteral reflux and 10 of 23 (43%) without demonstrable reflux. New renal scarring developed in 6 of the 7 kidneys (86%) associated with a neuropathic bladder or posterior urethral valves. In contrast, new scarring developed in only 10 of 31 kidneys (32%) associated with a normal bladder (p = 0.028). Excluding the kidneys associated with a neuropathic bladder or posterior urethral valves, new renal scarring developed in 3 of 12 (25%) with primary reflux, compared with 7 of 19 (37%) without vesicoureteral reflux. Except for the white blood count and the species of infecting bacteria, no other statistically significant differences could be found between those cases in which scars did or did not develop. We conclude that acquired renal scarring only occurs at sites corresponding to previous areas of acute pyelonephritis, the acute parenchymal inflammatory changes of acute pyelonephritis are reversible and do not lead to new renal scarring in the majority of cases, and once acute pyelonephritis has occurred ultimate renal scarring is independent of the presence or absence of vesicoureteral reflux.     

Reflux nephropathy in infancy: a comparison of infants presenting with and without urinary tract infection.

PURPOSE: We compared the incidence of renal scarring in infants with high grade vesicoureteral reflux in those presenting with and without urinary tract infection. METHODS AND METHODS: We reviewed the medical records of 81 male and 46 female infants (194 renal refluxing units) with a mean age of 4 months who had grade IV or V primary vesicoureteral reflux and underwent an anti-reflux procedure between 1984 and 1997. Dimercapto-succinic acid (DMSA) scans and voiding cystourethrography were performed in all cases. Patients were followed for 2 to 16 years, including 90% for greater than 3 years. Renal ultrasound and DMSA scan were done at followup. RESULTS: A total of 97 patients (76%) (148 refluxing renal units) presented clinically with urinary tract infection. The initial DMSA scan demonstrated renal scarring in 40 of the 106 grade IV (38%) and 28 of the 42 grade V (67%) refluxing renal units. There was no scarring on followup in previously normal refluxing renal units. Of the patients 30 (24%) (46 refluxing renal units) were diagnosed before a urinary tract infection developed, 16 underwent screening due to vesicoureteral reflux in a sibling and in 10 reflux was initially suspected due to hydronephrosis on prenatal ultrasound. In the remaining 4 patients vesicoureteral reflux was suspected during abdominal ultrasound to investigate abdominal pain, jaundice, associated hypospadias and fetal alcohol syndrome, respectively. DMSA scan showed evidence of scarring in 6 of 21 grade IV (29%) and 9 of 25 grade V (36%) refluxing renal units in this group. Followup revealed scarring in only 1 previously normal refluxing renal unit. CONCLUSIONS: The incidence of reflux nephropathy in primary grade V vesicoureteral reflux is lower in cases detected by screening and with treatment it remained lower than in cases of urinary tract infection that presented clinically. Early treatment of grade V vesicoureteral reflux made possible by screening may prevent renal damage.     

Screening siblings for vesicoureteral reflux

PURPOSE: Publications on screening the siblings of patients with reflux were reviewed to determine the overall incidence and severity of reflux and renal scarring in siblings, and identify factors that predict siblings more likely to have reflux. MATERIALS AND METHODS: A MEDLINE search for 1985 to the present was performed. Of 34 articles on familial reflux only 11, including 1 abstract, on sibling screening were used in this analysis. RESULTS: The mean incidence of reflux in siblings in all studies was 32% (570 of 1,768). Of the siblings with reflux approximately two-thirds had grades I to II disease. Only 22 of 1,051 siblings (2%) had reflux greater than grade III. Reflux was unilateral in 162 of 307 cases (53%). Certain factors predicted the chance of sibling reflux. Sibling age varied inversely with the incidence of reflux. A twin relationship and absent dysfunctional voiding symptoms in the index patient may predict a higher chance of reflux in a sibling. The mean incidence of renal abnormality in siblings with reflux was 11%. The incidence of reflux and renal abnormality in the sibling population undergoing screening was 3%. In more than half of the siblings with an abnormal renal evaluation there was no history of urinary tract infection. CONCLUSIONS: The studies reveal an incidence of reflux in siblings greater than in the general population. These data do not prove that screening and treating asymptomatic siblings decreases infectious renal scarring. Studies in a control group that consider sibling age are still needed to determine the benefit of screening asymptomatic siblings.     

Distribution of renal parenchymal damage on 99m-Tc DMSA scintigraphy in vesico-ureteric reflux

During a 2 year period renal scintigraphy was performed in 64 children prior to surgery for vesico-ureteric reflux (VUR). In total 126 kidneys were examined. Renal scintigraphy was performed 3 hours after intravenous injection of 99m-technetium labelled dimercaptosuccinic acid (DMSA). The renal parenchyma was assessed as normal in 64 kidneys and abnormal in 62. Renal parenchymal damage was revealed in the upper pole in 42 cases, the middle lateral part in 27, the lower pole in 47 and the middle medial part in 25. The whole kidney was affected in 21 cases. Damage within one or two poles was present in 59 of the 62 kidneys with parenchymal damage. Renal scintigraphy is regarded a sensitive technique for detection of renal parenchymal damage. The DMSA scintigraphy can reveal even minor scars. It can be recommended as a routine investigation in evaluating children with VUR.     

Post-pyelonephritic renal scars are not associated with vesicoureteral reflux in children

PURPOSE: Children with pyelonephritis are at risk for renal damage. We assess the value of clinical signs and urological abnormalities in predicting renal scars in children following pyelonephritis. MATERIALS AND METHODS: A total of 64 hospitalized children (29 females and 35 males, median age 2.9 years) underwent ultrasonography and technetium labeled dimercapto-succinic acid (DMSA) scintigraphy imaging within 1 week following the diagnosis of the first pyelonephritis. Voiding cystourethrography was performed 8 weeks after the diagnosis. Followup DMSA scintigraphy was performed in 58 patients after 2 years of followup. RESULTS: Urological abnormalities observed were vesicoureteral reflux (VUR, grade 2 or higher) in 11 patients (19%), nonrefluxing and nonobstructed megaureter in 2 (4%) and pyeloureteral obstruction in 1 (2%). The first DMSA scintigraphy showed parenchymal defects in 48% of patients. VUR did not increase the risk of renal defects. At 2 years after the infection 12 of the 58 patients (21%) had renal scars. Nine of these patients did not have VUR. However, 2 patients with high grade VUR and repeat infections demonstrated deterioration of kidney function during followup. The patients with renal scars were older than those without scars (3.1 vs 0.8 years, p = 0.0291) at the time of infection. CONCLUSIONS: Renal scars after first pyelonephritis are in most cases not associated with abnormalities of the urinary tract, but are caused by the infection itself. However, structural abnormalities may predispose to recurrent infections. Following pyelonephritis new renal scars may develop in all age groups in both sexes.     

Direct comparison of radiology and nuclear medicine cystograms in young infants with vesico-ureteric reflux

OBJECTIVE: To determine the sensitivity of the direct radionuclide cystogram (DRC) in detecting vesico-ureteric reflux compared with the micturating cysto-urethrogram (MCU) in the same initial setting, in infants younger than one year. PATIENTS AND METHODS: The results from the dual cystograms of 62 refluxing infants < 1 year old (mean 0.58) were compared. Results from same-day renal scintigraphy with dimercaptosuccinic acid (DMSA) in 60 of the 62 infants were also compared with the reflux grades. RESULTS: Reflux was detected in 105 units, 96 detected on the DRC and 47 on the MCU, representing a sensitivity of 91% and 45%, respectively. The DRC missed half of grade 1, 20% of grade 2 and 6% of grade 3 reflux. Reflux at low bladder filling rates (DRC) represented 40% of all reflux units, and a half (52%) of scarred renal units detected by DMSA scintigraphy. CONCLUSIONS: In young infants the MCU may fail to detect significant reflux and the DRC may fail to detect the lesser grades. The combination of both cystograms in the initial investigation of reflux provides more comprehensive information.     

Vesicoureteral reflux increases the risk of renal scars: a study of unilateral reflux

The aim of this study was to assess the impact of vesicoureteral reflux (VUR) on renal scar following acute pyelonephritis by comparing the refluxing renal units with nonrefluxing renal units in children with unilateral primary VUR. Forty-eight children with unilateral primary VUR diagnosed after the first pyelonephritis were enrolled. Mean age of patients was 1.0±1.6 years (29 boys and 19 girls). All patients underwent renal ultrasonography and renal 99 m-technetium dimercaptosuccinic acid (DMSA) scan within three days following the diagnosis of pyelonephritis, and voiding cystourethrography (VCU) was performed soon after fever subsided and the infection was controlled. The DMSA scan was rechecked six months after the initial study when the first scan showed a renal defect. The first DMSA showed renal defects in 34 (70.8%) out of 48 of the refluxing renal units and in 13 (27.1%) out of 48 of the nonrefluxing renal units (P<0.01, OR: 6.54). At six months after the infection, 23 (47.9%) out of 48 refluxing renal units and seven (14.6%) out of 48 nonrefluxing renal units had renal scars on DMSA scan (P<0.01, OR: 5.39). The prevalence of renal scars did not vary significantly according to the grade of VUR. The CRP level on admission was significantly higher in patients with acute renal defect and scar. In conclusion, VUR increases the risk of post-pyelonephritic renal scars in children.     

Vesico-ureteric reflux in the young infant with follow-up direct radionuclide cystograms: the medical and surgical outcome at 5 years old

OBJECTIVE: To compare the 5-year outcome of 82 infants with vesico-ureteric reflux (VUR) against the initial (< 1 year) and follow-up results of the direct radionuclide cystogram (DRC). PATIENTS AND METHODS: An initial DRC was taken at a mean age of 0.6 years and the follow-up study at 1.7 years. VUR was graded using 'one-third bladder volume' grades (BVG) of 'low', 'moderate', 'high' and 'void', with 'low' considered the most severe. Renal scintigraphy was used to assess renal scarring in 80 of the 82 patients. The outcome at a minimum age of 5 years was defined as resolved reflux, those with corrective surgery or those still being medically followed. RESULTS: Those being followed comprised 29%, corrective reflux surgery 17% and resolved 54% of the patients. Children with VUR grades of 'high' or 'moderate' (as the worst grade either side) were more likely to have resolution than those with 'low' (by four and two times, respectively). Reflux at 'low' bladder volume was 2.6 times more likely to be associated with renal scarring than the other grades combined. 'Low' reflux was present in nine of 14 children needing surgery. There was a linear relationship between VUR grade and the scintigraphic findings. CONCLUSION: The severity of VUR can be assessed from the bladder-volume graded DRC. Continuing VUR at 'low' BVG is associated with increased renal scarring, resistance to natural resolution and corrective reflux surgery.     

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.     

Features of primary vesicoureteric reflux detected by prenatal sonography

Primary vesicoureteric reflux (VUR) was detected by prenatal sonography in 34 infants (55 renal units); males accounted for 31 cases. Associated genitourinary anomalies were common, occurring in 29% of the patients. Some element of hydroureteronephrosis was noted at initial cystography in 89% of refluxing renal units, but the degree of renal abnormality at 99Tc DMSA renography was not predicted by the severity of VUR. Overall, 60% of refluxing renal units were renographically abnormal. Although a high rate of urinary infection was encountered during follow-up, most DMSA assessments were carried out prior to infection and hence likely reflect congenital rather than acquired abnormalities. It was concluded that renal impairment associated with high grade primary VUR is frequently present at birth and not secondary to subsequent infection.