Scarring In Children Research Articles

A review of renal scarring in children.

It is now widely accepted that children with a proven urinary tract infection should undergo some form of diagnostic imaging to assess the presence of, or the potential to develop, renal scarring. The type of investigation which should be performed is controversial. Some centres still perform intravenous urography, others rely on ultrasound alone, while others believe that a 99Tc(m)-dimercaptosuccinic acid (99Tc(m)-DMSA) scan is essential. This review discusses the advantages and disadvantages of these techniques by drawing from the extensive literature currently available. The consensus view is that a DMSA scan is the most sensitive method of detecting renal scarring and of highlighting the kidney at risk of developing scarring. It is hoped that wider early use of DMSA scintigraphy will lead to a fall in the number of children who develop end-stage renal disease.

Development of renal scarring in children with urinary tract infections

Development of renal scarring in children with urinary tract infections

Relationship of asymptomatic bacteriuria and renal scarring in children with neuropathic bladders who are practicing clean intermittent catheterization

Objective: To determine whether untreated asymptomatic bacteriuria is associated with renal scarring in children with neuropathic bladders managed with clean intermittent catheterization (CIC). Design: Retrospective study of 207 patients aged 1 to 30 years (mean 11.9 ± 5.5 years) treated with CIC for a mean duration of 6.6 ± 3.9 years by the spina bifida program at Children's National Medical Center. All patients were examined for renal scarring with dimercaptosuccinic acid (DMSA) renal scans. Catheterized urine cultures were obtained annually, but bacteriuria (>10,000 colony-forming units of a single organism per milliliter) was treated only if the patients had symptoms or if vesicoureteral reflux (VUR) was present. Results: Of 207 children, 176 (85%) had one or more episodes of untreated asymptomatic bacteriuria and 72 (35%) had one or more febrile episodes associated with positive urine culture results. Biannual DMSA scans detected 54 new scarring episodes in 42 patients. Of newly recognized scars, 55% were preceded within 1 year by a febrile infection, 26% were detected in patients with VUR and asymptomatic bacteriuria, and 19% were detected in new patients during their initial examination. Univariate analysis revealed that new scarring was present in 35 of 176 patients with asymptomatic bacteriuria compared with 7 of 31 patients without ( p = 809). Logistic regression analysis revealed that factors associated with scarring were febrile infections (adjusted odds ratio [OR] = 30.6, 95% confidence interval [CI] = 9.8 to 95.8), age more than 20 years (OR = 4.3, CI = 1.01 to 18.5), the presence of bladder trabeculation (OR = 2.7, CI = 1.0 to 7.6), and VUR (OR = 58.8, CI = 6.3 to 547.3), but asymptomatic bacteriuria was not associated with scarring. Conclusion: In the absence of VUR, asymptomatic bacteriuria in patients undergoing CIC is not a significant risk factor for scarring and does not require antibiotic therapy. (J P EDIATR 1995;127:368-72)

Serum intercellular adhesion molecule (ICAM-1), a marker of renal scarring in infants with vesico-ureteric reflux.

To determine if serum intercellular adhesion molecule (ICAM-1) levels correlate with renal scarring in children with vesico-ureteric reflux (VUR). Serum ICAM-1 levels were measured in 81 children (29 boys and 52 girls, age range 2 months-13 years) with VUR using an enzyme-linked immunosorbent assay (ELISA) and compared with levels in a control group of 24 children (16 boys and eight girls, age range 2 days-13 years) with no urological abnormalities. The mean serum ICAM-1 level in the control group was 202 +/- 79 ng/mL (mean +/- 1 SD) compared with 347 +/- 96 ng/mL in children with VUR (P < 0.001). Fifteen of 26 children under 2 years of age demonstrated renal scarring while 18 of 44 children older than 2 years exhibited renal scarring. The mean serum ICAM-1 level in patients who were < 2 years of age and had renal scarring was 408 +/- ng/mL, significantly higher than in those who had no renal scarring (296 +/- 68 ng/mL, P < 0.01). In contrast, there was no difference in serum ICAM-1 levels in patients > 2 years of age with or with no renal scarring (353 +/- 87 and 325 +/- 91 ng/mL, respectively). Serum ICAM-1 levels are significantly higher in children with VUR and may represent a valuable marker of tubular damage in younger children with VUR.

Increased risk of facial scars in children taking nonsteroidal antiinflammatory drugs

Children with rheumatic disease (N = 250) were examined for shallow facial scars similar to those described in drug-induced pseudoporphyria. Users of a nonsteroidal antiinflammatory drug were 2.4 times as likely as nonusers to have four or more facial scars; this relative risk was increased to 6.0 in users of naproxen. (J PEDIATR 1994;125:819-22)

Increased risk of facial scars in children taking nonsteroidal antiinflammatory drugs.

Children with rheumatic disease (N = 250) were examined for shallow facial scars similar to those described in drug-induced pseudoporphyria. Users of a nonsteroidal antiinflammatory drug were 2.4 times as likely as nonusers to have four or more facial scars; this relative risk was increased to 6.0 in users of naproxen.

Can ultrasound reliably detect renal scarring in children with urinary tract infection?

One hundred children with a proven urinary tract infection were studied prospectively using both ultrasound (US) and 99mTc dimercaptosuccinic acid (DMSA) scintigraphy to assess the efficacy of US in the detection of renal scarring. Sixty-nine girls and 31 boys with an age range of 0.5-11.8 years were studied. DMSA scintigraphy detected 19 scarred kidneys in 17 children. Scarring was classified as mild, moderate or gross. US detected a total of seven of the scarred kidneys (sensitivity 37%). US detected 0/6 kidneys with mild scarring, 1/7 kidneys with moderate scarring and 6/6 kidneys with gross scarring. Four kidneys with scarring on DMSA showed abnormalities other than scarring on US. 8/19 scarred kidneys were thought to be normal on US. It is important to detect renal scarring in young children and US cannot be relied upon for this purpose. It should therefore be supplemented with DMSA scintigraphy.

Dimercaptosuccinic Acid Renal Scintigraphy For The Evaluation of Pyelonephritis and Scarring: A Review of Experimental and Clinical Studies

Renal cortical scintigraphy has been reported to be useful in children for confirmation of the diagnosis of acute pyelonephritis. Subsequent experimental studies have demonstrated that dimercaptosuccinic acid (DMSA) scintigraphy, when compared directly with histopathology, is highly reliable for the detection and localization of parenchymal inflammatory changes associated with acute pyelonephritis. Recent clinical studies of acute pyelonephritis using DMSA scintigraphy reveal that the majority (50 to 91%) of children with febrile urinary tract infections have abnormal DMSA renal scan findings and that the majority of these children do not have demonstrable vesicoureteral reflux. However, when vesicoureteral reflux is present, renal cortical abnormalities are demonstrated by DMSA scintigraphy in 79 to 86% of the kidneys. In children with febrile urinary tract infections routine clinical and laboratory parameters are not reliable in the differentiation of acute pyelonephritis, documented by DMSA renal scan findings, from urinary tract infections without parenchymal involvement. Furthermore, the presence of P-fimbriated Escherichia coli associated with febrile urinary tract infections does not reliably predict those kidneys that have acute parenchymal inflammation demonstrated by DMSA renal scans.DMSA is also the isotope agent of choice for the detection of renal scarring. Clinical studies report greater sensitivity of DMSA renal scintigraphy for the detection of renal scarring when compared with the excretory urogram, particularly in infants and young children. In a recent prospective study of post-pyelonephritic renal scarring in children we found that acquired renal scarring only occurs in sites corresponding exactly to previous areas of acute pyelonephritis demonstrated by DMSA scintigraphy at the time of infection. Furthermore, once acute pyelonephritis occurs, ultimate renal scarring is independent of the presence or absence of vesicoureteral reflux. These findings provide convincing evidence that renal parenchymal infection, rather than vesicoureteral reflux, is the prerequisite for acquired (postnatal) renal scarring. Vesicoureteral reflux as a risk factor for acquired renal scarring is directly related to its role as a risk factor for acute pyelonephritis. We conclude that DMSA scintigraphy is a valid tool for confirming the diagnosis of acute pyelonephritis in children and for identifying kidneys at risk for subsequent renal scarring.

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.

Evaluation of renal scars by technetium-labeled dimercaptosuccinic acid scan, intravenous urography, and ultrasonography: A comparative study

The objective of our prospective study was to compare the sensitivity and specificity of ultrasonography, intravenous pyelography, and dimercaptosuccinic acid scan in detecting scarred kidneys. Twenty-seven consecutive subjects with recurrent urinary tract infections, vesicoureteral reflux, scarred kidneys, or a combination of these problems had all three imaging procedures performed. With the total number of scars serving as the gold standard, the sensitivity (94%) and specificity (100%) in identifying renal scars in children were highest for the DMSA scan. Intraobserver (95%) and interobserver (90%) reliability were also high for the DMSA scan. However, the clinical interpretation of the increased sensitivity of the DMSA scan is unknown. Changes on the scan not identified by intravenous urography may not represent true scars. Research into the long-term significance of these scars is indicated.

8. Functional significance of the degree of renal scarring in children with urinary tract infection

8. Functional significance of the degree of renal scarring in children with urinary tract infection

5. A comparison of DMSA and ultrasound in the detection of renal scars in children

5. A comparison of DMSA and ultrasound in the detection of renal scars in children

Development of renal scars in children: missed opportunities in management. South Bedfordshire Practitioners' Group.

To assess the antecedent medical care of children with renal scars. Retrospective study of both general practice and hospital records. 12 Group practices in south Bedfordshire and the radiology and paediatric outpatient departments of a district general hospital. 23 Children with renal scars (six boys, 17 girls) from the 12 group practices, identified from outpatient, radiology, and general practice records. Number of children in whom a diagnosis of urinary tract infection had been made without prior examination of a mid-stream specimen of urine; number of children who had had a confirmed urinary tract infection that had not been investigated further; number who had experienced delays in investigation or referral; and number who had received inadequate follow up. In all, 11 of the children had received suboptimal medical care, but the management of the other 12 could not have been better. The most common error was failure to investigate possible urinary tract infections, but follow up of confirmed infections was also inadequate. These problems occurred in hospital as well as in general practice. Opportunities for intervention had been missed in nearly half of this sample of children with renal scars.

The growth of circumferential scars of the major airways from infancy to adulthood

The factors affecting the development and prognosis of scarred airways in children are presented from a long-term follow-up study of 14 cases of tracheobronchial lesions following either injury or operation. Four children managed by endoluminal treatment developed severe stenosis and required treatment, later as adults, by laser resection in 2 cases and by laryngotracheal plastic enlargement and resection with anastomosis in 1 case each. The follow-up of 7 children managed by plastic procedures showed inconsistent results: they were good or excellent in 3 cases but with a decrease in the laryngotracheal diameter of 36%, 28% and 7% respectively. The laryngotracheal calibre decreased in 2 patients to 45% due to partial fibrous stenosis. Resection and anastomosis was required in the remaining 2 patients after 11 and 12 years for severe re-stenosis. The 3 patients who underwent immediate surgical resection all had an excellent clinical and morphological result, with a decrease in the laryngotracheal diameter of only 7%, 13% and 19% after a follow-up of 18, 20 and 15 years, respectively. These results show that the growth capacity of scars in children's airways is closely related to residual sclerosis following the initial treatment. It is thus suggested that primary resection and anastomosis should be performed in as many cases as possible. In the performance of plastic procedures, special attention should be paid to complete resection of the fibrotic tissues. Finally, a very long postoperative follow-up is always required in children in order to assess the development of the airway.

99mTechnetium-Dimercapto-Succinic Acid Renal Scanning and Excretory Urography in Diagnosis of Renal Scars in Children

We compared the ability of excretory urography (without tomography) and 99mtechnetium-dimercapto-succinic acid renal scanning to detect renal scars in 32 children with primary vesicoureteral reflux. These children did not have hydronephrosis, renal failure or urinary tract obstruction. In all cases both studies were conducted within a 10-month period. The findings from both modalities were in agreement for 51 of the 64 renal units evaluated (80 per cent). Evaluation of the excretory urogram indicated 6 cases of diffuse and 2 of focal scarring that were not detected by evaluation of the renal scan. The sensitivity of excretory urography to detect renal scars was 84 per cent and the specificity was 83 per cent. The 99mtechnetium-dimercapto-succinic acid renal scan showed 5 cases of focal renal scarring not detected by excretory urography. The sensitivity of the renal scan to detect renal scars was 77 per cent and the specificity was 75 per cent. We conclude that neither study alone could effectively replace the other for the detection of renal scars, and recommend that both be included in the initial evaluation and followup of patients with renal scars.

New development and progression of renal scarring in children with primary VUR.

To study the development of new scars and progression of previous scarring, we analysed 711 children with primary VUR. New scar or progression of previous scarring was observed in 7.3% of the kidneys with reflux. Factors which promote the formation of new scars are high-grade VUR, recurrent UTIs and high-pressure bladder which results in high-pressure reflux. The average age of new scarring was from 7 to 9 years. We emphasize the importance of the follow-up study until the age of 15 years, even after reflux has stopped following surgery.

Optimal Use of 99mTechnetium-Glucoheptonate Scintigraphy in the Detection of Pyelonephriticscarring in Children: A Preliminary Report

Renal scintigraphy represents the optimal modality for the detection of renal scars. 99mTechnetium-glucoheptonate is rapidly accumulated by the kidney through glomerular filtration and active transport by renal tubular cells. This permits rapid visualization of the renal parenchyma in the early phase (1 to 3-minute images) and subsequent imaging of the collecting system and ureters. About 10 to 15 per cent of the injected activity remains in the kidney, labeling the cells of the proximal convoluted tubules (late phase or 1 to 2-hour images). The late phase has been used more commonly to assess renal parenchymal damage.Early and late phase glucoheptonate scanning was performed in 42 children as part of the evaluation of recurrent febrile urinary tract infections with or without a history of vesicoureteral reflux. Inter-observer reliability to interpret glucoheptonate scans was good (early, 83 per cent agreement and late, 93 per cent agreement). The ability of glucoheptonate scanning to detect renal scarring in children with febrile urinary tract infections was equivalent with the early or late phase of the study. In 6 patients renal scarring was detected on only the early phase scan and in 7 scarring was detected only in the late phase. Although the detection rates are equivalent the over-all detection of scarring is improved by using both phases. Therefore, the early phase of the glucoheptonate scan may be a valuable adjunct to conventional glucoheptonate scan methodology used for the detection of renal scarring in children with recurrent urinary tract infections. (J. Urol, part 2, 140: 1175-1177, 1988)

New development and progression of renal scarring in children with primary VUR

New development and progression of renal scarring in children with primary VUR

Distribution of Renal Scars and Intrarenal Reflux in Children with a Past History of Urinary Tract Infection

The distribution of renal scars in children with vesicoureteral reflux (VUR) and a past history of urinary tract infection was studied to see whether a correlation existed between renal scarring and intrarenal reflux. In 37 children with one or more scars in one or both kidneys, scarring was significantly more frequent in the polar areas than in the lateral area. In 7 children with intrarenal reflux (IRR), the distribution of IRR was almost identical with that of renal scarring. When children with marked VUR (grade IV-V) were analyzed separately, a uniform distribution of scars was found. It was concluded that fused papillae, which normally are most frequent in the polar area, are a prerequisite for the development of IRR/renal scars.

Vesico-uretero-renal reflux and the kidney.

The most frequent complications of non-obstructive vesico-uretero-renal reflux (VUR) are segmental renal scars. These scars are confined to segments with intrarenal reflux which are, in addition, exposed to bacterial infection. Primarily, only gaping collecting duct orifices, confined to compound papillae and mainly situated at the kidney poles, allow intrarenal reflux. Scar contraction and obstruction seem to be able to transform closed collecting duct orifices into gaping ones, thereby enlarging the parenchymal area prone to intrarenal reflux and to renal scarring. Contrary to earlier reports, a recent survey has documented that new scars in children develop with significant frequency beyond 5 years of age. There is a greater tendency for scarring to develop with more severe VUR, but new renal scars can develop with all grades of VUR. Early and adequate antibiotic treatment decreases the extent of scarring. The results of experimental studies in which renal scarring developed in piglets with bladder decompensation resulting from intravesical obstruction but without bacterial infection may be relevant to the few children with proximal urethral valves and hypertonic neurogenic bladders but not to the large number with non-neurogenic detrusor instability or detrusor sphincter dyssynergia. Prospective studies have not shown different recurrence rates of urinary tract infections in medically managed compared with surgically managed children. The frequency of acute pyelonephritic attacks decreased significantly after operation.