The predictive value of ultrasonography in evaluation of infants with posterior urethral valves

Predicting and Modifying Risk for Development of Renal Failure in Boys with Posterior Urethral Valves

PURPOSE OF REVIEW

The purpose of this review is to bring the reader up to date on the current risk factors for the development of renal deterioration in the boys with posterior urethral valves (PUV) and approaches to modify this risk.

RECENT FINDINGS

Renal bladder ultrasound (RBUS) is routinely performed in boys with PUV and recent advancements allow imaging processing that can more accurately quantify renal parenchyma and correlate this with risk for renal loss. Refinement of urine studies may improve our ability to stratify patients into renal loss categories. Use of videourodynamics (VUDS) allows refined assessment of the valve bladder to identify those who might benefit from secondary procedures and/or the addition of targeted pharmacotherapy to improve bladder emptying or dangerous storage pressures. All boys with a history of PUV are at a significant long-term risk of renal deterioration. The literature suggests that several technical advances have improved our ability to predict this risk, although there needs to be further refinement and validation before widespread use. Utilization of close follow-up, VUDS, pharmacotherapy, and bladder drainage provide the best methods to improve care to this group of patients and if more studies confirm their utility, adoption of these as part of standard of care protocols may be warranted.

Renal and Adrenal Ultrasonography: a valuable diagnostic tool in the salt-wasting infant

The major differential diagnosis in 'salt-wasting' infants (characterised by hyponatraemia and hyperkalaemia) is that of an adrenal or renal disorder. Appropriate management relies on rapid diagnosis, but existing guidelines do not highlight the role of ultrasonography. We describe how ultrasound may lead to a more rapid diagnosis in disorders of sex development (DSD) and other potential 'salt-wasting' infants.

CONCLUSION

Ultrasonography as a diagnostic tool in infants with salt-wasting or DSD needs to be more widely recognised.

The significance of detrusor wall thickness as a prognostic factor in pediatric bladder outlet obstruction

PURPOSE

The purpose of this study is to determine detrusor thickness as a prognostic factor in posterior urethral valves.

METHODS

The medical information of 41 patients diagnosed with posterior urethral valves at our institute was retrospectively reviewed. The serum creatinine level after bladder decompression, results of ultrasonography, and voiding cystourethrography were compared between groups divided according to the final bladder and renal function. Detrusor thickness was measured using Müller's method.

RESULTS

The median detrusor thickness was 1.3 mm (0.4-2.5 mm). After median 45.6 months (7.2-96.0 months) of follow-up, impaired bladder function (IBF) was observed in 14 patients. In multivariate analysis, detrusor thickness greater than 1.3 mm (odds ratio, 32.6; 95% confidence interval, 3.1-340.6; P = .004) was the only independent risk factor for later IBF. Final renal function impairment developed in 24 patients (58.5%), and 3 patients (7.3%) were diagnosed with end-stage renal disease after median 66.0 months (32.4-133.2 months) of follow-up period. On multivariate analysis, age-specific elevated serum creatinine level at presentation (odds ratio, 11.1; 95% confidence interval, 1.1-112.5; P = .042) was an independent risk factor.

CONCLUSIONS

Detrusor thickness more than 1.3 mm on ultrasonography was an independent prognostic factor for later IBF.

Timing of posterior urethral valve diagnosis and its impact on clinical outcome

OBJECTIVE

Our goals were to assess long-term outcome for patients with posterior urethral valves (PUV) and determine the impact of the timing of diagnosis.

PATIENTS AND METHODS

We reviewed the hospital records for patients with PUV treated in 1994-2008. Only those patients diagnosed, treated surgically, and followed clinically at our center were included.

RESULTS

There were 52 patients with PUV. Thirty-nine were diagnosed by 1 year of age (early diagnosis cohort), while 13 were diagnosed after 1 year (late diagnosis cohort). Mean follow up after valve operation was 7.2 years (range 15 months-14 years). Chronic renal failure rates were not statistically different between the early and late diagnosis groups after surgical intervention: 48% (14/29) vs 25% (3/12), P = 0.30. Among the early diagnosis cases, 10% (3/29) eventually required renal transplant, while no child in the late diagnosis group has developed end-stage renal disease to date (P = 0.55).

CONCLUSIONS

Gestational age at diagnosis is an important predictor of postnatal renal outcome. Our results suggest that diagnosis after 1 year of age is associated with a lower risk of developing renal insufficiency on long-term follow up.

Posterior urethral valve

BACKGROUND

Posterior urethral valve (PUV) is a significant cause of morbidity, mortality and ongoing renal damage in children. It accounts for end-stage renal disease in a proportion of children. This article aims at highlighting the current trend in the management of boys with posterior urethral valve.

DATA SOURCES

PubMed/Medline and bibliographic search for posterior urethral valve was done. Relevant literatures on presentation, pathology, evaluation, management and outcomes of PUV were reviewed.

RESULTS

PUV which is increasingly diagnosed prenatally presents a spectrum of severity. The varied severity and degree of obstruction caused by this abnormality depend on the configuration of the obstructive membrane within the urethra. The decision to intervene prenatally is dependent on gestational age, amniotic volume, and renal function of fetal urine aspiration. Identification of the patients who may benefit from early intervention remains inconclusive. Endoscopic ablation of the valve is the gold standard of treatment but use of Mohan's valvotome and other modalities are invaluable in developing countries where endoscopic facilities are limited. Proximal urinary diversion may result in poor bladder compliance and should be reserved for patients with persisting or increasing upper urinary tract dilatation, increasing serum creatinine or inappropriate instruments. The behavior of the bladder and its subsequent management after valve ablation may influence the long-term renal outcome in PUV patients.

CONCLUSIONS

The care of children with PUV continues to improve as a result of earlier diagnosis by ultrasound, developments in surgical technique and meticulous attention to neonatal care. The ultimate goal of management should be to maximize renal function, maintain normal bladder function, minimize morbidity and prevent iatrogenic problems.

Posterior urethral valves: multivariate analysis of factors affecting the final renal outcome

PURPOSE

Posterior urethral valves represent the most common obstructive uropathy in children with a broad spectrum of clinical severity. We evaluated prognostic variables affecting the outcome of renal function in such children.

MATERIALS AND METHODS

Between 1987 and 2004, 120 patients with a mean age of 2 years with posterior urethral valves were treated initially with valve ablation at our center. We studied certain parameters, including age at presentation, serum creatinine (initial and nadir), initial creatinine clearance, renal ultrasound findings (hydronephrosis and renal parenchymal echogenicity), vesicoureteral reflux on initial voiding cystourethrogram, bladder dysfunction and popoff mechanisms such as the syndrome of large vesical diverticulum, urinoma and ascites. Long-term renal outcome was assessed.

RESULTS

Followup was 2 to 16 years (median 3.6). Renal insufficiency developed at the end of followup in 44 patients (36.5%). Serum creatinine at hospital admission, nadir serum creatinine, initial creatinine clearance and renal parenchymal echogenicity were significant predictors of the final renal outcome (p < 0.05). Patient age at diagnosis (2 or less vs greater than 2 years), upper tract dilatation, the presence or absence of vesicoureteral reflux, popoff mechanisms and bladder dysfunction had no significant impact on future renal function. On multivariate analysis nadir serum creatinine was the only independent prognostic factor.

CONCLUSIONS

Our data confirm the high prognostic value of nadir creatinine after primary valve ablation. Also, initial serum creatinine, creatinine clearance and renal parenchymal echogenicity on initial renal ultrasound correlate significantly with long-term renal function in children with posterior urethral valves.

Cleft palate, arachnoid cyst and posterior urethral valve

A 5-month-old infant presented with cleft palate, febrile urinary tract infection and abnormal movements. His urinary stream was poor and investigations revealed posterior urethral valve and grade V vesicoureteric reflux. This baby was investigated for seizure activity and on MRI of the brain was found to have a large arachnoid cyst, splaying the occipital horns and compressing the posterior aspect of third ventricle leading to dilatation of the ventricles. This seems to be a very unusual coexistence of three abnormalities in one patient for which no plausible explanation can be given. It appears to be a chance finding.

Renal pyramid echogenicity in ureteropelvic junction obstruction: correlation between altered echogenicity and differential renal function

BACKGROUND

Improvement in resolution and use of high-frequency transducers in US has enabled visualization of previously unreported changes in medullary pyramid echogenicity in children with obstructive hydronephrosis.

OBJECTIVE

To determine whether these unreported changes in echogenicity and morphology of the renal pyramids in ureteropelvic junction (UPJ) obstruction correlate with differential renal function (DRF) of the kidney as determined by technetium-99m mercaptoacetyltriglycine ((99m)Tc-MAG3) scan.

MATERIALS AND METHODS

Renal sonograms in 60 children with UPJ obstruction were retrospectively reviewed. Children were divided into three groups based on the echogenicity of the pyramids: (1) normal echogenicity of the pyramids, (2) increased echogenicity of the pyramids with maintained corticomedullary differentiation (CMD), and (3) loss of CMD. DRF, as determined by (99m)Tc-MAG3 scan, of the obstructed kidney of > or =45% was considered normal and of < or =44% was considered abnormal based on a published study correlating histological changes with DRF. Fisher's exact test was performed for assessing the association between DRF and altered echogenicity of the pyramids.

RESULTS

In group 1, which consisted of 13 patients with normal pyramids on US, DRF was normal in 11 and abnormal in two. In group 2, which consisted of 33 patients with echogenic pyramids and preserved CMD, DRF was normal in 15 and abnormal in 18. In group 3, which consisted of 14 patients with complete loss of CMD, DRF was normal in 2 and abnormal in 12. There was a strong correlation between abnormal pyramids and DRF (P=0.0009). The risk ratio (RR) of DRF becoming abnormal for those kidneys with abnormal echogenicity of the pyramids with preserved CMD (group 2) compared to normal pyramid echogenicity (group 1) was 1.56 (95% CI 1.088-2.236). The RR of DRF becoming abnormal for those kidneys with loss of CMD (group 3) compared to normal pyramid echogenicity (group 1) was 5.571 (95% CI 1.530-20.294).

CONCLUSION

We observed that in obstructed kidneys the echogenicity of the pyramids may be abnormal. Increased echogenicity of the pyramids correlated weakly with abnormal DRF and does not necessarily indicate poor renal function. However, loss of CMD strongly correlated with poor renal function.

Initial management of complex pediatric disorders: prunebelly syndrome, posterior urethral valves

Prunebelly syndrome and posterior urethral valves are conditions of detrusor dysfunction associated with antenatal urethral obstruction. The resultant severe hydroureteronephrosis and renal dysplasia initiate a sequence potentially leading to renal failure. This article reviews clinical features and explores neonatal evaluation and treatment for both conditions. A comprehensive approach to initial management aimed at optimal renal preservation and bladder rehabilitation is proposed.

Sonographic diagnosis of urethral anomalies in infants: value of perineal sonography

OBJECTIVE

To assess the value of urethral sonography including a perineal approach in evaluating urethral anomalies in infants.

METHODS

A radiology database review identified 88 patients (mean age +/- SD, 64 +/- 84 days) who underwent voiding cystourethrography (VCUG) and urethral sonography as part of extended sonography of the urinary tract. Sonographic and VCUG images and reports were reviewed to assess agreement between both modalities for detection of urethral anomalies.

RESULTS

Sonography facilitated the correct diagnosis of all 3 posterior urethral valves. The only urethral diverticulum, the only ectopic ureteric insertion into the urethra, the only urogenital sinus, and the only urethrovaginal fistula were also shown on sonography. In 73 (94%) of 78 cases, sonography correctly showed the absence of anomalies. In 5 infants, sonography could not reliably assess the urethra and showed indirect signs of urethral anomalies; however, these patients had normal urethras on VCUG.

CONCLUSIONS

Our data show that sonography of the urethra is a valuable tool for diagnosis of urethral anomalies. Especially, negative findings on sonography are highly suggestive of the absence of urethral anomalies. Positive or equivocal sonographic findings should indicate VCUG.

Distal urinary obstruction

Despite the sound experimental basis and initial promise of early animal models, the results of antenatal intervention have been disappointing, with high rates of misdiagnosis of urethral valves, complications from vesicoamniotic shunting, perinatal mortality, and long-term renal impairment and bladder dysfunction in survivors. The recent development of a cystoscopic approach might obviate some of these problems, but to date the procedure been limited by technical difficulty in negotiating the urethrovesical angle. Overcoming these difficulties through equipment modifications might allow definitive testing of whether or not alleviating distal urinary obstruction in utero is beneficial.

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.

Conventional imaging in paediatric uroradiology

OBJECTIVE

To briefly describe basic conventional imaging in paediatric uroradiology.

METHOD

The state of the art performance of standard imaging techniques (intravenous urography (IVU), voiding cystourethrography (VCU), and ultrasound (US)) is described, with emphasis on technical aspects, indications, and patient preparation such as adequate hydration. Only basic applications as used in routine clinical work are included.

RESULT AND CONCLUSION

Conventional imaging methods are irreplaceable. They cover the majority of daily clinical routine queries, with consecutive indication of more sophisticated modalities in those patients who need additional imaging for establishing the final diagnosis or outlining therapeutic options.

Results of systematic voiding cystourethrography in infants with antenatally diagnosed renal pelvis dilation

OBJECTIVES

To assess the yield of neonatal renal ultrasonography as a predictor of abnormalities on voiding cystourethrography (VCUG).

STUDY DESIGN

We prospectively followed 264 infants with antenatal renal pelvis dilation. Two successive neonatal renal ultrasound examinations were performed at day 5 and 1 month after birth. VCUG was performed in all infants.

RESULTS

Neonatal ultrasound findings were abnormal in 190 infants (72% of total). Among them, 63 (33%) had an abnormal VCUG. The most common abnormalities were primary vesico-ureteral reflux (VUR) in 30 infants, VUR into the lower pole of a duplex kidney in 14, refluxing megaureter in 9, posterior urethral valves in 5, and ureterocele in 5. When both neonatal ultrasound findings were normal (74 infants), the VCUG showed abnormalities in only 5 (6.7%) patients (4 low-grade primary VUR and 1 posterior urethral valve). The sensitivity, specificity, positive predictive value, and negative predictive value of 2 successive ultrasound scans in the neonatal period to predict an abnormality on VCUG were 93%, 35%, 33%, and 93%, respectively.

CONCLUSIONS

A normal-appearing urinary tract on 2 successive neonatal ultrasound scans rarely coexists with abnormal findings at VCUG. Therefore, in such patients, VCUG does not seem justified.

Accuracy of renal-bladder ultrasonography as a screening method to suggest posterior urethral valves

PURPOSE

We determine the usefulness of ultrasonography as a screening modality to support the diagnosis of posterior urethral valves.

MATERIALS AND METHODS

A retrospective chart analysis was performed of 93 consecutive boys with newly diagnosed posterior urethral valves from August 1985 through February 1999. Of the 93 boys 65, including 62 who underwent renal and bladder ultrasonography, had preoperative renal sonography available and constitute our study population. Patient age range at presentation was newborn to 13 years, with 33 of the 65 boys presenting as infants (age 1 year or younger). Presentation included fetal hydronephrosis in 13 cases, urinary tract infection in 18, voiding dysfunction in 9, abdominal mass in 6, renal insufficiency in 5, failure to thrive in 4, hematuria in 1 and other in 9.

RESULTS

Preoperative sonography identified bilateral hydronephrosis in 48 boys (74%), unilateral hydronephrosis in 9 (14%) and no hydronephrosis in 8 (12%). Bladder sonography revealed an abnormal bladder (thickened, trabeculated and/or significantly distended) in 54 boys (87%). An abnormal bladder was seen in 43 of the 46 boys with bilateral hydronephrosis, 6 of 8 boys with unilateral hydronephrosis and 5 of 8 with normal upper tracts. Only 3 of the 62 boys (5%) had a normal upper tract and bladder. The sensitivity of renal ultrasonography in suspecting posterior urethral valves was 88%, while sensitivity of renal-bladder ultrasonography was 95%. When stratifying for age younger than 4 years and 4 or older, the sensitivity of predicting posterior urethral valves with renal-bladder ultrasonography was 87% and 98%, respectively.

CONCLUSIONS

While voiding cystourethrography remains the imaging gold standard for the diagnosis of posterior urethral valves, renal-bladder ultrasonography is an appropriate screening study for a boy suspected to have the condition. Renal-bladder ultrasonography may prove particularly useful in the evaluation of the boy with significant voiding dysfunction before deciding on a more invasive study, such as voiding cystourethrography.

Accuracy of renal-bladder ultrasonography as a screening method to suggest posterior urethral valves

PURPOSE

We determine the usefulness of ultrasonography as a screening modality to support the diagnosis of posterior urethral valves.

MATERIALS AND METHODS

A retrospective chart analysis was performed of 93 consecutive boys with newly diagnosed posterior urethral valves from August 1985 through February 1999. Of the 93 boys 65, including 62 who underwent renal and bladder ultrasonography, had preoperative renal sonography available and constitute our study population. Patient age range at presentation was newborn to 13 years, with 33 of the 65 boys presenting as infants (age 1 year or younger). Presentation included fetal hydronephrosis in 13 cases, urinary tract infection in 18, voiding dysfunction in 9, abdominal mass in 6, renal insufficiency in 5, failure to thrive in 4, hematuria in 1 and other in 9.

RESULTS

Preoperative sonography identified bilateral hydronephrosis in 48 boys (74%), unilateral hydronephrosis in 9 (14%) and no hydronephrosis in 8 (12%). Bladder sonography revealed an abnormal bladder (thickened, trabeculated and/or significantly distended) in 54 boys (87%). An abnormal bladder was seen in 43 of the 46 boys with bilateral hydronephrosis, 6 of 8 boys with unilateral hydronephrosis and 5 of 8 with normal upper tracts. Only 3 of the 62 boys (5%) had a normal upper tract and bladder. The sensitivity of renal ultrasonography in suspecting posterior urethral valves was 88%, while sensitivity of renal-bladder ultrasonography was 95%. When stratifying for age younger than 4 years and 4 or older, the sensitivity of predicting posterior urethral valves with renal-bladder ultrasonography was 87% and 98%, respectively.

CONCLUSIONS

While voiding cystourethrography remains the imaging gold standard for the diagnosis of posterior urethral valves, renal-bladder ultrasonography is an appropriate screening study for a boy suspected to have the condition. Renal-bladder ultrasonography may prove particularly useful in the evaluation of the boy with significant voiding dysfunction before deciding on a more invasive study, such as voiding cystourethrography.

Sonography of the neonatal genitourinary tract

Ultrasound has become the modality of choice for the evaluation of the neonatal genitourinary tract. High frequency linear, vector, and curved array transducers (7 MHz, 5 MHz, 12 MHz) and portability of the equipment make a rapid bedside evaluation with exquisite anatomic detail possible. A major advantage of sonography over other modalities is real time observation and circumvention of sedation.

Prognostic value of initial renal ultrasound in patients with posterior urethral valves

PURPOSE

Increased cortical echogenicity and loss of corticomedullary differentiation on the initial renal ultrasound study are said to be predictive of poor renal function in patients with posterior urethral valves. We reviewed ultrasound results in a group of patients with posterior urethral valves to test this hypothesis.

MATERIALS AND METHODS

We reviewed the radiology records of 19 patients in year 1 of life with posterior urethral valves seen since 1976 for whom records were available. The degree of corticomedullary differentiation and cortical echogenicity was compared with serum creatinine after 4 days of catheter drainage and creatinine clearance at the most recent followup.

RESULTS

Median followup was 96 months. At the last followup the sensitivity, specificity, and positive and negative predictive values of increased cortical echogenicity and loss of corticomedullary differentiation for predicting creatinine clearance less than 69 ml. per minute per 1.73 m.2 were 90, 57, 75 and 80, and 100, 33, 71 and 100%, respectively.

CONCLUSIONS

Increased cortical echogenicity and loss of corticomedullary differentiation are relatively insensitive predictors of eventual renal function in boys with posterior urethral valves. In a significant proportion of patients with normal renal function the initial renal ultrasound study revealed echogenic kidneys, although only a small proportion with poor renal function had normal kidneys.

Can careful ultrasound examination of the urinary tract exclude vesicoureteric reflux in the neonate?

The aim of the study was to determine whether a urinary tract appearing normal when assessed by meticulous ultrasound (US) examination may coexist with vesicoureteric reflux (VUR) and whether a normal US scan can be used to exclude VUR, thereby avoiding unnecessary voiding cystourethrography (VCUG). The US features of 35 neonates with known VUR were reviewed. Criteria studied included pelvic dilatation above 7 mm on a transverse scan, calyceal or ureteral dilatation, pelvic or ureteral wall thickening, absence of the corticomedullary differentiation (CMD) and signs of renal dysplasia (small kidney, thinned or hyperechoic cortex and cortical cysts); all signs that have been shown to result from or to be associated with VUR. 57 refluxing renal units (RRU) were found among the 35 patients. VUR was bilateral in 22. Among the 57 RRU, at least one US anomaly that would have prompted VCUG was present in 50 (87.7%). Pelvic dilatation above 7 mm was present in 29 RRU (50.9%) only. Calyceal dilatation was present in 24 RRU, the dilatation involving the calyces but not the renal pelvis in seven. Ureteral dilatation was observed in 15 RRU. Pelvic or ureteral wall thickening was present in seven RRU. CMD was absent in 32 RRU (56.1%). US signs of dysplasia were found in 19 RRU. No US anomaly was found in seven RRU (12.3%) in six patients. A careful and meticulous US examination of the neonatal urinary tract allows the detection of over 87% of RRU by showing at least one sonographic abnormality. It is concluded that a normal appearing urinary tract on US does not usually coexist with VUR and that in such cases VCUG is not necessary.

Congenital nephropathies and uropathies

Although congenital nephropathies and uropathies only represent a fraction of possible genitourinary diseases detected during childhood, they have serious and sometimes avoidable morbidity and mortality. Advances in genetic, molecular, and cellular biology research continue to better define embryologic insults to normal organogenesis and offer the promise that many of these conditions might be avoided in the future. For now, awareness of these entities and their varied presentations and manifestations is crucial so that prompt evaluation and aggressive multidisciplinary management assures the affected child optimal growth and development.

Posterior urethral valves, pressure pop-offs and bladder function

The pop-off mechanisms that sometimes occur with posterior urethral valves have well recognized implications for renal function, such that 1 or both kidneys can be protected from the deleterious effects of elevated bladder pressures. What has not been defined is the significance, if any, of pressure pop-offs to the developing bladder and ultimate bladder function. To answer this question we reviewed the records of 63 boys with posterior urethral valves. Eight boys who were not yet toilet trained had unevaluable bladder outcomes. Of the 55 remaining boys there was 1 or more pressure pop-off in 39 (71%), including massive (grade 5) reflux, massive reflux associated with ipsilateral renal dysplasia, a patent urachus, large diverticula and urinomas. Bladder outcomes were judged as favorable or unfavorable on the basis of urodynamic parameters and/or patient clinical status. A statistically significant positive correlation was found between the presence of a pop-off and a favorable outcome. Favorable characteristics were found in 34 of 39 bladders (87%) with pressure pop-offs. In contrast, only 9 of 16 bladders (55%) without pressure vents had favorable outcomes. In addition, 5 of the remaining 7 boys without pressure vents have required augmentation cystoplasty. A direct correlation between absolute number of pop-offs and favorable bladder outcome was also noted, further emphasizing this relationship. The presence of a pressure pop-off is a favorable prognostic sign for ultimate bladder function in boys with posterior urethral valves.

Prevalence of hypertension in children with primary vesicoureteral reflux

This study was undertaken to determine the prevalence of hypertension in children with primary, uncomplicated vesicoureteral reflux (VUR) and to evaluate the relationship between blood pressure (BP), grade and duration of reflux, and renal scarring. Subjects were identified retrospectively during a 17-year period; of 146 subjects who agreed to participate, 129 (88.4%) were female. Mean age at diagnosis was 5.0 years (range, 1 month to 16 years), and at follow-up was 14.4 years (range, 5 months to 21 years). Mean duration of follow-up was 9.6 years. Renal scarring was detected in 34.3% of patients by intravenous pyelogram, ultrasonography, or both. The BP at diagnosis was linearly related to the grade of reflux, but values were not higher than expected norms for age. At follow-up, mean systolic and diastolic BP were at the 41.6 percentile and the 18.7 percentile, respectively. No patient's BP was above the 55th percentile. After a mean follow-up period of 10 years, we conclude that primary, uncomplicated VUR, regardless of the number of documented urinary tract infections, duration and severity of reflux, modality of therapy, presence of renal scarring, and duration of follow-up, is not associated with the development of hypertension. Hypertension does not appear to be a complication of VUR and urinary tract infection unless there is preexisting dysplasia.