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Background Pulmonary arterial hypertension (PAH) is a life-threatening disease with risk stratification-based treatment strategy in adults. Although the risk factors have been studied individually in children, effective risk stratification is still lacking. We have tested the prognostic accuracy of pediatric PAH risk factors in our patient group. Patients and methods Records of 58 PAH patients treated between 1995 and 2019 were reviewed retrospectively. Median age at diagnosis was 4.2 years (range, 0.1-16.1 years), and follow-up was 5.4 years (range, 0.01-24.1 years). Data collected at diagnosis were demographics, World Health Organization functional class, evidence of right ventricular failure, and parameters of echocardiography and cardiac catheterization. Results Mortality was 29% and 33% reached the composite endpoint. Patients with idiopathic PAH (n = 12) had increased risk of mortality compared with the congenital heart disease-associated PAH group (n = 32) (P = .0024). Neither the initial World Health Organization functional class staging nor the echocardiographic parameters significantly predicted the prognosis. The number of risk factors had no significant prognostic value either. In contrast, patients with higher pulmonary vascular resistance index (PVRI) had significantly increased risk (each 10 Wood units ⋅ m2 increase in PVRI being associated with 49.1% higher hazard, P = .0048). Conclusions Survival analysis showed that PAH etiology might be an important determinant in pediatric PAH risk stratification. We confirmed that PVRI has predictive value in prognostic assessment. We could not establish the prognostic value of nonweighted single risk factors or their combination to predict pediatric PAH outcome due to the low sample size, but these results indicate that such studies are warranted.

This paper will discuss, from a subjective perspective, aspects of paediatric radiology in different parts of the world. A small survey was conducted to improve our understanding of radiologic care and to explore the current status of paediatric radiology worldwide. As part of this survey, the number of paediatric radiologists and radiologists was compared to the population and to the number of children in 34 countries. The number of paediatric radiologists varied between 0 and 50 per million children. In general, the proportion of paediatric radiologists compared to radiologists is poor, even in countries with an aging population. Unfortunately, developing countries are severely underserved in terms of radiology, while paediatric radiology is almost nonexistent. The author, based on her experiences as a volunteer paediatric radiologist in Malawi, India, Cambodia and Tanzania, highlights some of the difficulties in radiologic care in developing countries. The author's personal experiences and the survey both suggest that the need for paediatric radiology is high across the world, but the supply is not sufficient, especially in developing countries, when compared to developed countries.

PubMedID: 31038179 Background: There is no consensus regarding the timing of dialysis therapy initiation for end-stage kidney disease (ESKD) in children. As studies investigating the association between timing of dialysis initiation and clinical outcomes are lacking, we aimed to study this relationship in a cohort of European children who started maintenance dialysis treatment. Methods: We used data on 2963 children from 21 different countries included in the European Society of Pediatric Nephrology/European Renal Association-European Dialysis and Transplant Association Registry who started renal replacement therapy before 18 years of age between 2000 and 2014. We compared two groups according to the estimated glomerular filtration rate (eGFR) at start: eGFR ?8 mL/min/1.73 m2 (early starters) and eGFR

In hypoplastic left heart syndrome (HLHS), long-term outcome is closely related to right ventricular function. Echocardiography and magnetic resonance imaging (MRI) are routinely used for functional assessment. MRI 2D-tissue feature tracking (2D-FT) allows quantification of myocardial deformation but has not yet been applied to HLHS patients. We sought to investigate the feasibility of this technique and to compare the results to 2D-speckle tracking echocardiography (2D-STE). In routine MRI 2D anatomical four chamber view, cine images were recorded in 55 HLHS patients (median age 4.9 years [1.6, 17.0]). Regional and global peak systolic longitudinal strain (LS) and strain rate (LSR) were determined using 2D-FT software. Echocardiographic four chamber view was analyzed with 2D-STE. Visualization of all myocardial segments with MRI was excellent, regional, and global LS and LSR could be assessed in all data sets. In 2D-STE, 28% of apical segments could not be analyzed due to poor image quality. Agreement of 2D-FT MRI and 2D-STE was acceptable for global LS, but poor for global LSR. In MRI, regional LS was lower in the septal segments, while LSR was not different between the segments. GLS and GLSR correlated with ejection fraction (GLS: r = - 0.45 and r

Cardiovascular (CV) diseases play a leading role in the mortality of adult liver transplant (LT) recipients. However, data regarding CV risk factors in children after LT remain sparse. The present study assessed the presence of CV risk factors and signs of CV impairment in LT children.A total of 42 LT recipients (21 men, age 9.93 ± 3.57 years) were studied. Body composition [body mass index standard deviation score, percentage of body fat (by bioimpedance analysis)], lipid profiles, glycemic control, blood pressure, and arterial stiffness [assessed by aortic pulse wave velocity (PWV)] were evaluated. The effect of different treatment modalities [tacrolimus (TAC) (n = 30) or cyclosporine (CyA) (n = 11)] was also analyzed.Almost 18% of children were overweight or obese. Patients on TAC had a significantly higher body fat mass and percentage of body fat compared with the CyA group (P 0.02). Borderline to high lipid values were present in 40% of patients. Children on CyA had higher serum cholesterol levels compared to TAC (P 0.004). Nineteen percent of patients had hypertension. Half of the patients had glomerular filtration rate values90 mL/min/1.73 m, whereas PWV values were above the 95th percentile in 12%.Increased body fat, chronic kidney disease, high lipid content, hypertension, and increased arterial stiffness are already present and are in part related to the type of immunosuppression regimen in LT children5 years following transplantation. Long-term follow-up is needed to evaluate their impact on CV health and survival.

Cardiovascular mortality rate in patients with end-stage renal disease is 3 magnitudes higher than in the general population; it remains 10-fold higher after successful renal transplantation (Tx). Among others, obesity and hypertension can exert deleterious effects on vascular structure and function after Tx. Successful kidney transplantation may induce excessive weight gain in part because of the effects of steroid treatment.The purpose of this study was to evaluate the presence of obesity in Tx children, their obesity-related metabolic disturbances, and to assess their blood pressure and arterial stiffness in relation to obesity. Forty-one transplant children (age, 15.7 [3.5] years; 28 males) were studied. Body composition was assessed by body mass index (BMI), waist circumference, skin-fold measurements, and multifrequence bioimpedance analysis. Glucose metabolism, blood pressure, and arterial stiffness (with the use of pulse wave velocity) were studied. Age- and sex-dependent parameters were expressed as standard deviation scores (SDS).The prevalence of overweight (BMI85%) increased from 3.2% to 24.4% at 49 months (3-183) (median, range); the BMI SDS increased from -0.27 (0.79) to 0.67 (1.35) after Tx. There was a close correlation between BMI SDS and the percentage of body fat and body fat mass in the Tx group (r = 0.80; r = 0.94, P = .0001). Children with disturbed glycemic control (n = 14) had higher percentage of body fat and higher blood pressure compared with those with normal glucose metabolism (P .05). There was no difference in pulse wave velocity between the lean and obese patients.The prevalence of overweight or obese patients in the Hungarian pediatric renal cohort is low at transplantation and rises subsequently. Overweight is associated with disturbed glycemic control and increased blood pressure; however, these disturbances are not yet reflected by stiffening of the arteries. Strategies are needed to prevent obesity, its impact on hypertension, and cardiovascular disease in pediatric transplantation.

Background/Aims: To assess the relationship between bone and vascular disease and its changes over time after renal transplantation. Metabolic bone disease (MBD) is common in chronic kidney disease (CKD) and is associated with cardiovascular (CV) disease. Following transplantation (Tx), improvement in CV disease has been reported; however, data regarding changes in bone disease remain controversial. Methods: Bone turnover and arterial stiffness (pulse wave velocity (PWV)) were assessed in 47 Tx patients (38 (3-191) months after Tx). Results: Bone alkaline phosphatase (BALP), osteocalcin (OC) and beta-crosslaps were significantly higher in Tx patients, and decreased significantly after one year. There was a negative correlation between BALP, OC and steroid administered (r=-0.35;r=-0.36 respectively). PWV increased in the Tx group (1.15 SD). In patients with a follow up of Conclusions: Increased bone turnover and arterial stiffness are present following kidney transplantation. While bone turnover decreases with time, arterial stiffness correlates initially with bone turnover, after which the influence of cholesterol becomes significant. Non-invasive estimation of bone metabolism and arterial stiffness may help to assess CKD-MBD following renal transplantation.

Background: The impact of different dialysis modalities on clinical outcomes has not been explored in young infants with chronic kidney failure. Study Design: Cohort study. Setting & Participants: Data were extracted from the ESPN/ERA-EDTA Registry. This analysis included 1,063 infants 12 months or younger who initiated dialysis therapy in 1991 to 2013. Factor: Type of dialysis modality. Outcomes & Measurements: Differences between infants treated with peritoneal dialysis (PD) or hemodialysis (HD) in patient survival, technique survival, and access to kidney transplantation were examined using Cox regression analysis while adjusting for age at dialysis therapy initiation, sex, underlying kidney disease, and country of residence. Results: 917 infants initiated dialysis therapy on PD, and 146, on HD. Median age at dialysis therapy initiation was 4.5 (IQR, 0.7-7.9) months, and median body weight was 5.7 (IQR, 3.7-7.5) kg. Although the groups were homogeneous regarding age and sex, infants treated with PD more often had congenital anomalies of the kidney and urinary tract (CAKUT; 48% vs 27%), whereas those on HD therapy more frequently had metabolic disorders (12% vs 4%). Risk factors for death were younger age at dialysis therapy initiation (HR per each 1-month later initiation, 0.95; 95% CI, 0.90-0.97) and non-CAKUT cause of chronic kidney failure (HR, 1.49; 95% CI, 1.08-2.04). Mortality risk and likelihood of transplantation were equal in PD and HD patients, whereas HD patients had a higher risk for changing dialysis treatment (adjusted HR, 1.64; 95% CI, 1.17-2.31). Limitations: Inability to control for unmeasured confounders not included in the Registry database and missing data (ie, comorbid conditions). Low statistical power because of relatively small number of participants. Conclusions: Despite a widespread preconception that HD should be reserved for cases in which PD is not feasible, in Europe, we found 1 in 8 infants in need of maintenance dialysis to be initiated on HD therapy. Patient characteristics at dialysis therapy initiation, prospective survival, and time to transplantation were very similar for infants initiated on PD or HD therapy. (C) 2016 by the National Kidney Foundation, Inc.

Arterial stiffness (Ast) individually predicts cardiovascular (CV) mortality. Ast increases via vascular calcification and can be characterized by pulse wave velocity (PWV). We assessed the influence of mineral and bone metabolism on Ast in dialyzed (D) and renal transplanted (Tx) children by measuring fetuin-A and bone markers [bone-specific alkaline phosphatase (BALP); beta-CrossLaps (β)]. Normalized PWV/height (PWV/h) of 11 D and 17 Tx patients was measured by applanation tonometry. Levels of calcium (Ca), phosphate (P), fetuin-A, and bone markers were analyzed. Ca × P/fetuin-A ratio was calculated to characterize the balance of calcification and inhibition. Cumulative dose of calcitriol was also assessed. Fetuin-A was lower in D and Tx compared with healthy controls. Bone markers and Ca × P/fetuin-A of D were significantly higher than those of Tx and controls. In D PWV/h correlated with Ca × P/fetuin-A and BALP (r = 0.8; p = 0.005, r = 0.6, p = 0.05, respectively); BALP correlated with Ca × P/fetuin-A (r = 0.7, p = 0.01). In Tx, there was a correlation between calcitriol administered before transplantation and PWV/h (r = 0.5, p = 0.04). Increased bone turnover was coupled with an increased potential of calcium-phosphate precipitation, as shown by the increased Ca × P/fetuin-A. It might explain the connection between disturbed mineral and bone metabolism and Ast. Tx might be beneficial on Ast, though follow-up studies are needed.

Turner-szindrómában a cardiovascularis és renalis malformatiók gyakori előfordulása jól ismert. A ritkábban tapasztalt gastrointestinalis vérzés jellemző oka e betegségben az irodalmi adatok szerint intestinalis teleangiectasia, gyulladásos bélbetegség és portalis hypertensio. Hároméves, Turner-szindróma miatt gondozott gyermek súlyos, transzfúziót igénylő gastrointestinalis vérzéssel járó esetét ismertetik a szerzők. A haematochesia hátterében a képalkotó vizsgálat praehepaticus portalis hypertensiót igazolt, amelynek oka a vena portae veleszületett hiánya volt. A máj szövettani vizsgálata az intrahepaticus artériák és vénák anomáliáját írta le. Az eset kapcsán a szerzők a Turner-szindrómához társuló májelváltozásokat, valamint a vena portae elzáródásának gyermekkorban előforduló okait elemzik.

Arterial stiffness increases with age. This process is accelerated by end-stage renal disease (ESRD). Pulse wave velocity (PWV) increases with arterial stiffness. In this study, PWV of 133 healthy individuals (6-23 y of age) and 11 patients on dialysis was measured to establish the normal values of PWV and to compare them with those in ESRD. Age-matched (A-C) and height- and weight-matched (H/W-C) control groups were used. Thereafter, PWV was indexed to height and the data were reevaluated. The role of the risk factors including serum calcium, phosphate, parathyroid hormone (PTH), and the time on dialysis was analyzed using a score system. PWV correlated with age, weight, height, blood pressure, and heart rate. ESRD patients were smaller than A-C and older than H/W-C. PWV of patients with ESRD did not differ from A-C; however, it was elevated in comparison to H/W-C. In both healthy and ESRD patients, the PWV/height ratio was independent of age. PWV/height was increased in ESRD. There was a correlation between PWV/height and the risk factor score. Controls matched for height and weight or PWV/height should be used in cases of growth failure. A number of risk factors responsible for increased arterial stiffness are present in ESRD.

PAH is a progressive life-threatening disease in children. While parenteral prostacyclin therapy improves survival in patients with severe PAH, central line-related complications are common. Our aim was to assess the efficacy, safety, and tolerability of subcutaneous treprostinil treatment in pediatric PAH patients. Eight patients were treated with subcutaneous treprostinil at the Pediatric Heart Center Budapest. Indications for subcutaneous treprostinil therapy were clinical worsening and/or echocardiographic progression or switch from intravenous to subcutaneous therapy. Following treprostinil initiation, clinical status improved or did not change in four of eight patients. Two patients were lost early during treprostinil therapy, parenteral treprostinil as a rescue therapy being insufficient in these cases. The final dose in long-term treated patients was between 60 and 100 ng/kg/min. Aside from thrombocytopenia, other severe side effects were not observed. Potts shunt was performed as palliative treatment in two cases. Three patients had successful lung transplantation, and one died while on the waiting list. Long-term subcutaneous treprostinil could be a safe and well-tolerated therapy in children with severe PAH even at higher doses. It may serve as an alternative to intravenous prostacyclin treatment allowing to avoid the potential complications of permanent central line placement.

Given the increase in CV morbidity after RTx and the scarcity of CV events in pediatrics, surrogate markers should be assessed to characterize CV damage in this population. AASI is a marker of arterial stiffness in adults, predicting cardio- and cerebrovascular morbidity. Our aim was to assess the determinants of AASI in RTx children (n = 54, 15.5 ± 3.5 yr) and to examine its relationship to central PWV. AASI was calculated from 24 h ABPM. PWV was determined by applanation tonometry, body composition by multifrequency bioimpedance measurement. The dipping state, volume overload, and time on dialysis were the main predictors of AASI (p

To estimate the value of pulse wave velocity (PWV) in pediatric cardiovascular disease, prospective studies are needed. Various instruments based on different measurement principles are proposed for use in children, hence the need to test the comparability of these devices in this younger population. The objective of this study was to compare PWV measured by oscillometry (Vicorder (VIC)) with the gold standard of applanation tonometry (PulsePen (PP), Sphygmocor (SC)). PWV was measured in 98 children and young adults (age: 16.7(6.3-26.6) years (median(range)) with the above three devices at the same visit under standardized conditions. Mean PWV measured by VIC was significantly lower than that measured by SC and PP. There was no difference following path length correction of the VIC measurement (using the distance between the jugular notch and the center of the femoral cuff), (PP: 6.12(1.00), SC: 5.94(0.91), VIC: 6.14(0.75) m s(-1)). Velocities measured by the three devices showed highly significant correlations. Bland-Altman analysis revealed excellent concordance between all three devices, however, there was a small but significant proportional error in the VIC measurements showing a trend toward lower PWV measured by VIC at higher PWV values. Our study provides data on the three most frequently used instruments in pediatrics. Following path length correction of the VIC, all three devices provided comparable results. Thus, our work allows extrapolating data between previously established normal PWV values for children and forthcoming studies using these instruments to assess children at long-term risk of cardiovascular disease. The small proportional error of VIC needs additional technical development to improve the accuracy of the measurements.

Background. Cytomegalovirus (CMV) is endemic throughout the world, affecting most of the population, but the seroprevalence of CMV is known to vary among countries. CMV causes a mild infection in persons with intact immunity; however, CMV infection in organ transplantation is associated with significant morbidity and mortality. The present retrospective study was designed to evaluate the age-, gender-, and blood group-adjusted CMV seroprevalence among solid organ donors, representing fairly the overall Hungarian population (according to Hungarian Central Statistic Institute). This information is important for calculating risk-factors for CMV-seronegative recipients. No nationwide estimates of CMV seroprevalence in Hungary (as a representative of Eastern Middle Europe) have been published yet. Methods. We investigated 2070 organ donors for CMV seroprevalence by measuring the CMV-specific immunoglobulin G. The donors were divided into 3 age groups (2-20, 21-50, and 51-70 years old). A study was also conducted on a fourth group consisting of 200 residents from an old age home. CMV seroprevalence differences were searched according to age-, gender- and blood-group distribution. Results. The CMV seroprevalence of organ donors is 85% and of all investigated persons is 86%. The age-specific prevalence increases, starting from 72% in the first group to 99% in the fourth group. Seroprevalence of females was found to be significantly higher than of males (P = .0001). Conclusion. We have shown that the overall CMV seroprevalence in the Hungarian population is moderately high at 86%. The opportunity for CMV-seronegative recipients to get a graft from a seronegative donor is statistically only 2%. The seroprevalence of the youngest age group is 72% and so it can be concluded that the Hungarian population acquires the infection mainly in childhood or in the early adulthood. Female gender is a risk factor for CMV infection. This fact must be taken into consideration during the planning of patients' follow-up, prophylaxis, and therapy.

Contrast-enhanced voiding urosonography (VUS) is becoming more widely used for the diagnosis of vesicoureteric reflux (VUR). The purpose of this study was to evaluate the sensitivity of VUS using a second-generation ultrasound (US) contrast agent and compare it with standard fluoroscopic voiding cystourethrography (VCUG). A total of 183 children with 366 kidney-ureter units (KUUs) underwent VUS and VCUG in the same session with the same catheterization. VUS was performed after intravesical administration of 1 ml of a second-generation ultrasound contrast agent (UCA; SonoVue, Bracco, Italy). VUR was detected in 140 out of 366 cases (38%); in 89 (24.3%) by both methods, in 37 (10.1%) by VUS only, and in 14 (3.8%) by VCUG only. Although there was considerable agreement in the diagnosis of VUR by VUS and VCUG (κ=0.68, standard error [κ]=0.04), the difference in the detection rate of reflux between VUS and VCUG was significant (p

PTDM plays a role in chronic allograft nephropathy and decreases graft and patient survival. Considering the serious outcome of chronic hyperglycemia, the importance of early recognition and the few data in children, in this retrospective analysis we studied the characteristics and risk factors of PTDM in 45 pediatric renal transplant recipients receiving Tac or CyA-based immunosuppression. Fasting blood sampling and OGTT were performed. PTDM has been developed in six patients (13%), while seven children (16%) had IGT, with the overall incidence of a glucose metabolic disorder of 29% in pediatric renal transplants. Patients in the PTDM + IGT group were younger and had higher systolic blood pressure and serum triglyceride level than children with normal glucose tolerance. Multivariate analysis identified Tac treatment, Tac trough level, steroid pulse therapy and family history of diabetes to be associated with the onset of PTDM. In pediatric renal transplants, OGTT and frequent assessment of blood glucose levels might be essential not only in the post-transplant management, but also prior to transplantation, particularly with family history of diabetes. Careful monitoring and modified protocols help to minimize the side effects of Tac and corticosteroids.

The survival rate of premature infants has been significantly increased during the last decades. As a consequence, the problem of less imminent, slowly progressing, but also important disorders such as osteopenia of prematurity has been emerging. The diagnosis of osteopenia of prematurity is based evidence for less bone mineral density compared to fetuses or infants at the same gestational age in the absence of laboratory parameters and/or clinical signs for rachitis or other metabolic bone disease. The incidence of osteopenia among infants born before 28 weeks of gestational age are as high as 30%. The aim of this paper is to review the information regarding the prevention and treatment of osteopenia of prematurity and to summarize the preventive measures to avoid fractures or bone deformations and to achieve the genetically determined peak bone mass. The latter is essential for the prevention of osteoporosis in adulthood, a significant problem of public health.

Aim The aim of this study was to investigate the motor activity in the stomach of infants with repaired esophageal atresia (EA). Method Gastric myoelectrical activity was investigated by cutaneous electrogastrography in 15 infants after the surgical correction of EA. Ten infants with no gastrointestinal upset served as controls. Studies were done before and after a milk feed. The pH of the lower esophagus was measured for 24 hours to assess the gastroesophageal reflux (GER) in the infants with repaired EA. Results After feeding, a significant increase in bradygastria and decrease in tachygastria were observed as compared with the preprandial period. Compared with healthy infants, the electrogram showed pathological patterns in 73.3% (11/15) of EA patients. Twelve of 15 EA patients showed some clinical sign of GER, and 60% of the EA patients proved to be GER-positive on esophageal pH monitoring. There was no difference in the distribution of gastric myoelectrical waves between the GER-positive and GER-negative EA patients either before or after meal. Conclusion Cutaneous electrogastrography is a noninvasive, harmless method for obtaining indirect information about the motor function of the stomach. The abnormal changes in physiological gastric myoelectrical activity in EA patients can serve as markers of disturbed neuromuscular function and can play a role in the pathogenesis of feeding disturbances after operative correction of EA. Gastroesophageal reflux, which often occurs after surgical repair of EA, seems to be connected not only with disordered gastric myoelectric activity, but also probably with other factors such as artificially straightened esophagogastric angle or brachyesophagus.

The changes of gastric myoelectrical activity were investigated in 20 infants by cutaneous electrogastrography (EGG) before and after the surgical correction of infantile hypertrophic pyloric stenosis (IHPS). The dominance of 2-4 cycles per minute (CPM) "slow waves" is typical of the healthy gastric function. The shift of the dominant frequencies towards the slower frequency (0-2 CPM) is defined as bradygastria, whereas a shift towards the more frequent waves (4-10 CPM) is called tachygastria. Unlike with healthy infants, the electrogastrogram showed pathologic patterns in 85% (18 out of 20) of IHPS patients. In all except two of these infants with pathologic electrical patterns, the frequency of the waves significantly shifted towards tachygastria. The effect of feeding on the gastric myoelectrical activity could only be studied in limited (9/20) cases because of recurring vomiting during the preoperative period. In IHPS infants, a significant increase in the bradygastria group was observed in the postprandial period compared with healthy infants. Three to 5 days after surgical repair (pyloromyotomy) and the reintroduction of feeding in gradually increasing amounts, the gastric myoelectrical activity showed physiologic patterns again, showing that the pyloric function was back to normal. Cutaneous EGG is a useful, noninvasive method to obtain indirect information about the motor function of the stomach and might be further applicable to pediatric gastric motility disorders.

Complications of multicystic dysplastic kidney are rare, but hypertension and malignant transformation represent real danger.In a 10-year period, 94 infants (60 boys, 34 girls) with multicystic dysplastic kidney were diagnosed. The data obtained from these patients were compared to 70 children with solitary kidney of which 36 were newborns. In 80 cases (85%) the diagnosis of multicystic dysplastic kidney was already suspected by prenatal sonography.Abnormalities of the contralateral kidney were found in 15 of the 94 patients (16%). Complete involution of the multicystic dysplastic kidney was observed in 19, and a decrease in size in 42%. In 37 children (39%) the dysplastic kidney has been removed at the age of about 1 year because of no involution. The length of the contralateral kidney, compared to the normal standard was already significantly larger at birth. In newborn babies with unilateral renal agenesia the solitary kidney was also significantly longer.Compensatory hypertrophy of single functioning kidneys occurs in utero both in patients with multicystic dysplastic kidney and in those with unilateral renal agenesia. Based on the results of these and previous studies, early nephrectomy cannot be recommended in the newborn period. Surgery remains an option for patients who have no involution at the time of about 1 year of age.

Background. Pyeloplasty is an established treatment for pelviureteric junction (PUJ) obstruction. The postoperative change in the size of the renal pelvis and the kidney parenchyma are variable. Objective. To document the changes in renal pelvic size and renal parenchymal thickness following pyeloplasty and to establish that improvement of both parameters are good markers for improved urine flow. Materials and methods. A group of 267 newborns and young infants with suspected PUJ obstruction were investigated by ultrasound. Pyeloplasty was performed on 102 babies, and 165 patients were followed conservatively. Postoperative ultrasonography at 6 and 12 months was available in 88 patients. Results. One year after surgery, the renal pelvis was smaller in 76 % of the cases. The renal parenchyma was normal or had increased in 92 % of cases. Conclusion. Resolution of hydronephrosis after surgery is relatively slow, but renal parenchymal growth is rapid. Mild postoperative pelvic dilatation is frequent and does not indicate continued obstruction.