Continuous Arteriovenous Renal Replacement Therapy

As urea and creatinine clearances achieved by continuous arteriovenous hemofiltration tend to be low, efforts were made to increase urea and creatinine elimination by modifying the original continuous arteriovenous hemofiltration system. We investigated the urea and creatinine clearances of different continuous renal replacement therapy systems. Urea clearance achieved by spontaneous arteriovenous hemofiltration was 9.1 ml/min, suction-supported arteriovenous hemofiltration 15.3 ml/min, arteriovenous hemodiafiltration 15.4 to 19.3 ml/min, arteriovenous hemodialysis 18.9 to 22.1 ml/min. Creatinine clearances ranged between 11.1 (spontaneous arteriovenous hemofiltration) and 25.1 ml/min (arteriovenous hemodialysis). Continuous arteriovenous hemodialysis seems at present to be the ideal renal replacement therapy system to compensate azotemia in hypercatabolic patients. Its urea and creatinine clearances are high, its clinical tolerance good and it is simple and safe.

Arteriovenous Hemofiltration in Children with Multiple Organ System Failure

In the last year nine critically ill children with multiple organ system failure (MOSF) were treated by continuous arteriovenous hemofiltration (CAVH). The mean number of organ systems involved was five per patient (range 4 to 7). Mean duration of hemofiltration was 136 hours (range 10 to 432 h.). Mean ultrafiltration rates of 6.4 ± 3.0 ml/m2 b.s./min achieved mean serum creatinine levels of 2.39 ± 1.49 mg/dl. Hypervolemia and pulmonary edema were corrected rapidly by CAVH. Total parenteral nutrition with a mean caloric intake of 62 ± 15 kcal/kg b.w./day was provided throughout the hemofiltration period. In addition high ultrafiltration rates allowed delivery of large amounts of i.v. medications. CAVH is an ideal extracorporeal renal replacement system to control azotemia, fluid, electrolyte, and acid-base status in critically ill children. It carries the potential to improve survival rate in children with MOSF.

Consequences of nitrate leaching following stem-only harvesting of Swedish forests are dependent on spatial scale

Short-term increases in soil solution nitrate (NO(3)(-)) concentration are often observed after forest harvest, even in N-limited systems. We model NO(3)(-) leaching below the rooting zone as a function of site productivity. Using national forest inventories and published estimates of N attenuation in rivers and the riparian zone, we estimate effects of stem-only harvesting on NO(3)(-) leaching to groundwater, surface waters and the marine environment. Stem-only harvesting is a minor contributor to NO(3)(-) pollution of Swedish waters. Effects in surface waters are rapidly diluted downstream, but can be locally important for shallow well-waters as well as for the total amount of N reaching the sea. Harvesting adds approximately 8 Gg NO(3)-N to soil waters in Sweden, with local concentrations up to 7 mg NO(3)-N l(-1). Of that, ∼3.3 Gg reaches the marine environment. This is ∼3% of the overall Swedish N load to the Baltic.

Potential applications of three-dimensional ultrasound in the pediatric urinary tract: pictorial demonstration based on preliminary results

The aim of this study was to describe the potential of three-dimensional ultrasound (3DUS) in the urinary tract of neonates, infants, and children. The potential applications are illustrated based on our experience in 80 patients using two different 3DUS techniques. Various disease entities throughout the neonatal and pediatric age have been evaluated. The potential of 3DUS is discussed based on comparison with conventional 2DUS or other imaging (as clinically indicated), focused on the potentially improved renal parenchymal volume assessment. In our experience, 3DUS is feasible in neonates, infants, and children without sedation. It reduces imaging time, improves demonstration of complex anatomy and allows for evaluation of anatomy/pathology in any plane. The 3DUS improves volume assessment and follow-up comparison by offering an improved standardization and documentation. Rendered views of the dilated collecting system enable a comprehensive demonstration of hydronephrosis similar to intravenous urography or MR urography images. Additionally, 3DUS offers an ideal tool for training and education. Yet, limitations have to be acknowledged: areas inaccessible for 2DUS; poor quality of the original 2DUS acquisition; limited resolution; patient motion and breathing; cardiac pulsation creating artifacts and misregistration; equipment cost; lack of 3D DICOM standards creating problems with data storage; as well as system-inherent technical limitations. Nevertheless, the 3DUS holds the potential to become a valuable additional imaging tool for sonographic evaluation of the pediatric urinary tract.

Feasibility of MR urography in neonates and infants with anomalies of the upper urinary tract

The aim of this study was to evaluate the feasibility and diagnostic potential of dynamic MR urography (MRU) in neonates and infants with sonographically detected abnormalities of the upper urinary tract. Thirty infants (age range 5 days to 3 years, mean age 7.9 months; male:female: 22:8) underwent MRU using T2 and contrast-enhanced dynamic T1-weighted sequences. The results were compared with the findings of ultrasound ( n=30), intravenous urography (IVU, n=19) and/or scintigraphy ( n=25) based on the criteria suggestive of obstructive uropathy. Oral sedation was sufficient to perform MRU with diagnostic quality in 20 of 21 patients younger than 1 year; 9 older patients needed intravenous sedation. Diagnosis of the 66 renal units (58 kidneys, 29 successful examinations) included normal systems (contralateral units), duplex systems, vesico-ureteral reflux, obstructive megaureter, ureteropelvic junction obstruction and accompanying renal parenchymal disease, with complex pathology in 10 patients. Magnetic resonance urography demonstrated anatomy better than IVU, particularly the renal parenchyma, (ectopic) ureters, and poorly functioning dilated systems. Magnetic resonance urography was superior to US in showing ureteral pathology. Tiny cysts in dysplastic kidneys were better seen by US. Gadolinium-enhanced dynamic MRU allowed accurate assessment of obstruction applying IVU criteria. Here MRU matched IVU results, and most of the scintigraphic findings. Magnetic resonance urography can be performed in young infants with diagnostic quality using oral sedation. Magnetic resonance urography correctly depicts anatomy and allows assessment of the urinary tract better than US and IVU, with additional functional information. Magnetic resonance urography thus has the potential to replace IVU for many indications.

Amplitude coded-colour Doppler sonography in paediatric renal disease

The aim of our study was to assess the ability of amplitude coded-colour Doppler sonography (ACDS) to depict altered perfusion in paediatric renal disease in a prospective study. Colour Doppler sonography (CDS) and ACDS examinations were performed in 180 renal units (90 patients; age range newborn to 16 years) with unilateral or bilateral renal disease (e.g. reflux nephropathy, renal scars, end-stage renal disease, ureteropelvic junction obstruction, urinary tract infection, renal failure, haemolytic uraemic syndrome, nephrotic syndrome, systemic lupus erythematosus (LE), renal biopsy, congenital dysplasia, tumour/infiltration). The ACDS results were compared with scintigraphy or CT as well as to clinical findings. Amplitude colour-coded Doppler sonography accurately demonstrated normal vasculature in 49 of 51 healthy kidneys (= 96%); 3 healthy kidneys could not be evaluated due to motion/artefacts. In 39 of 43 kidneys with focally altered perfusion ACDS could be performed and correctly depicted focally impaired vasculature/perfusion in 35 kidneys (= 89.7%). Seventy-three of 83 kidneys with diffusely impaired perfusion could be evaluated by ACDS and altered pattern was correctly depicted in 58 kidneys (= 79.4%), with an overall percentage of agreement of 87.1%. Amplitude CDS appears to be useful in infants and children. Compared with CDS it improves visualisation of especially focally impaired vasculature/perfusion and should be considered a valuable adjunct to conventional investigations.

Effects of brash removal after clear felling on soil and soil-solution chemistry and field-layer biomass in an experimental nitrogen gradient

Biofuels, such as brash from forest fellings, have been proposed as an alternative energy source. Brash removal may affect the sustainability of forest production, e.g., through a change in the availability of cations and N in the soil. We report initial effects of brash removal on inorganic N content in humus and mineral soil, soil-solution chemistry, and field-layer biomass after clear felling an N-fertilisation experiment in central Sweden. The experiment comprised six different fertiliser levels, ranging from 0 to 600 kg N ha(-1). Urea was given every 5th year during 1967 to 1982 to replicated plots, giving total doses of 0 to 2400 kg N ha(-1). Clear felling took place in 1995, 13 years after the last fertilisation. The removal of brash decreased the NO3- content in the humus layer after clear felling. A decrease in the NO3- concentration of the soil solution was indicated during most of the study period as well. No effect of the previous N fertilisation was found in the humus layer, but in the mineral soil there was an increase in NO3- content for the highest N dose after clear felling ( p = 0.06). The soil-solution chemistry and the field-layer biomass showed an irregular pattern with no consistent effects of brash removal or previous fertilisation.

[Neonatal segmental cystic nephroma. A case report]

Multicystic segmental renal dysplasia is rare in early childhood. We report a case with prenatally recognized renal malformation. Prenatally a cystic renal malformation was detected sonographically; postnatally further evaluation was performed by Doppler sonography, contrast enhanced CT and voiding cysto-urethrography leading to the diagnosis of a multicystic segmental nephroma. Due to increasing size in spite of therapeutic and diagnostic sonographic guided punctures and the atypic manifestation the baby underwent heminephrectomy. The final histological diagnosis confirmed preoperativ findings.

CONCLUSION

Prenatally recognised cystiform renal malformations should be reevaluated postpartally by ultrasound and--as doubtful findings are found--further imaging might be necessary for follow up and for the decision on conservative or operative treatment.

Application of M-mode sonography to functional evaluation in pediatric patients

To assess the feasibility and advantages of functional motion-mode (M-mode) sonography in pediatric patients with various non-cardiac M-mode applications, 50 patients aged 6 days to 14.5 years with megaureter, diaphragmatic palsy and spinal cord malformation were studied. In addition to initial conventional brightness-mode gray-scale ultrasound. M-mode sonography was performed for evaluation of motion and possible impairment. The findings were compared with other imaging results. The impact of the sonographic results on clinical management was evaluated retrospectively. Impaired motion was demonstrated by conventional sonography in all cases. Only M-mode sonography enabled adequate documentation for comparison with follow-up examinations, but allowed only semiquantitative assessment. Thus even gradual improvement or deterioration can be followed in an unbiased way by using a better-documented investigation for comparison, though an objective 'ranking', especially of diaphragmatic movement, could not be achieved. M-mode sonography enables a non-invasive and non-ionizing evaluation and documentation of motion impairment in pediatric patients. It improves documentation of motion and enables a better comparison with previous findings. It is especially useful for follow-up in evolving disease.

Arteriovenous fistula after renal biopsy in children

Our objective was to assess the prevalence and history of arteriovenous fistula after renal biopsy in pediatric patients by the use of color Doppler sonography. Fifty patients, aged 6 days to 18.5 years, underwent sonographically guided renal biopsy. Color Doppler sonography was performed prior to, during, and after the procedure. Postbiopsy hematoma was detected in 46 patients (92%), of whom 10 suffered clinically significant bleeds. Six patients (age range, 8 to 18.5 years) developed postbiopsy arteriovenous fistula. In three cases the arteriovenous fistula diminished spontaneously, one persisted without symptoms, and two symptomatic arteriovenous fistulas needed coil implantation. Color Doppler sonography demonstrated all arteriovenous fistulas 4 hours after the procedure and duplex Doppler sonography demonstrated the flow disturbances in the feeding and draining vessels. We conclude that color Doppler sonography allows noninvasive detection and follow-up study of postbiopsy arteriovenous fistula, thus helping to define management after interventional procedures.

Urinary N-acetyl-beta-D-glucosaminidase activity in patients with cystic fibrosis on long-term gentamicin inhalation

OBJECTIVE

To investigate possible renal toxicity of long-term gentamicin inhalation in patients with cystic fibrosis.

METHODS

Urinary N-acetyl-beta-D-glucosaminidase (NAG) activity was measured during routine respiratory clinic visits. Outpatient records were reviewed for data on long-term gentamicin inhalation, and parents and patients were interviewed for compliance. Exclusion criteria were irregular gentamicin inhalation, urinary infection or other febrile illness, intravenous aminoglycoside treatment during the previous three months, and diabetes mellitus. Patients were assigned to three groups: group 1, current gentamicin inhalation; group 2, previous gentamicin inhalation that had been stopped at least three months ago; and group 3, never any gentamicin inhalation.

RESULTS

52 patients (34 girls, 18 boys), mean (SD) age 11.5 (5.7) years, entered the study. Patients currently on gentamicin inhalation (n = 20) were significantly younger and had higher urinary NAG activity (0.83 (0.57) U/mmol creatinine) than the 23 patients without gentamicin inhalation (0.26 (0.10) (p = 0.0001) and the nine patients with previous gentamicin inhalation (0.32 (0.15) (p = 0.0125). Twelve patients on current gentamicin inhalation had raised NAG values but all those in groups 2 and 3 had NAG values within the normal range. In patients currently on gentamicin inhalation, there was a positive correlation between urinary NAG activity and cumulative dose of nebulised gentamicin (r = 0.60, p = 0.0049).

CONCLUSIONS

Long-term gentamicin inhalation in patients with cystic fibrosis poses a risk of renal toxicity. It is not known whether further treatment might result in more severe renal damage.

Continuous renal replacement therapy in critically ill patients

We describe our experience with continuous renal replacement therapy (CRRT) in critically ill neonates. From June 1995 to June 1997 36 critically ill oliguric or anuric infants and children underwent continuous arterio-venous (N = 17) or veno-venous (N = 15) renal support. In addition, four neonates were treated with continuous ultrafiltration (CUF) during extracorporeal membrane oxygenation (ECMO) because of severe diuretic-resistant hypervolemia. Their mean age was 9.8 +/- 1.5 days, their mean body weight 3.0 +/- 0.1 kg. The membrane surface area of the hemofilters ranged from 0.015 m2 to 0.2 m2 and the priming volume from 3.7 to 15 ml. For pump-driven hemofiltration a roller pump with pressure alarms, an air trap, an air bubble detector, and small blood lines was used. Fluid balance was controlled by a microprocessor controlled unit. The ultrafiltrate substitution fluid was based on bicarbonate in the majority of the patients and was partially or totally replaced according to the clinical situation. The mean duration of renal support was 97 +/- 20 hours, ranging from 14 to 720 hours. During arterio-venous and veno-venous hemofiltration the mean blood flow rates were 7.0 +/- 1.2 ml/min and 23.1 +/- 2.4 ml/min (P < 0.01), respectively, and the mean ultrafiltration rates 3.3 +/- 0.4 and 9.5 +/- 1.9 ml/min/m2 (P < 0.01), respectively. During continuous hemodiafiltration urea clearances increased by 300%. Overall survival rate was 66%. CRRT related complications included local bleeding at the catheter entrance site, partial thrombosis of the inferior or superior caval veins and transient ischemia due to femoral artery catheters. Continuous hemofiltration either driven in the arterio-venous or veno-venous mode is a very effective method of renal support for critically ill neonates to control fluid balance and metabolic derangement. Urea clearance can be improved by adding some dialysate fluid in a countercurrent direction to blood flow.

[Evaluation of renal vascularization using amplitude-coded Doppler ultrasound]

PURPOSE

To evaluate the benefit of "Colour Doppler Energy" (CDE) or "Power Doppler" applications in healthy kidneys and in renal disease including paediatric assessment.

PATIENTS AND METHOD

Ten healthy volunteers (range: neonate to adults) were studied using conventional colour Doppler sonography (CDS) and CDE in order to evaluate the visibility of intrarenal vasculature. In addition, ten children and ten adults with known renal disease were evaluated. The findings were compared to clinical, scintigraphic and biopsy results.

RESULTS

CDE showed far better visualisation of intrarenal vasculature than CDS. CDE demonstrated focal and diffuse reduced cortical perfusion with an overall accuracy of 95% and a sensitivity of 88%. In 7 healthy volunteers cortical vasculature was visualised throughout the kidney. In 3 infants incomplete visualisation was obtained because of motion artifacts. In the diseased kidneys, CDE findings correlated well with clinical findings, scintigraphy results and biopsy findings.

CONCLUSION

CDE can be successfully applied to adults and infants demonstrating renal vasculature in healthy kidneys and in kidneys with focally or diffusely altered perfusion.

The sonographically thickened wall of the upper urinary tract system: correlation with other imaging methods

BACKGROUND

Sonographically detected, upper urinary tract wall thickening (UUTWT) was reported to occur in urinary tract infection, urinary tract stone disease, rejection after renal transplantation and vesico-ureteral reflux (VUR). A possible association with obstruction can be hypothesized.

OBJECTIVE

The assessment of a potential relationship of UUTWT with VUR or obstruction in patients without one of the above-mentioned conditions.

MATERIALS AND METHODS

We analyzed 38 patients (74 upper urinary tracts) with at least unilateral UUTWT and concomitant imaging studies such as voiding cystourethrography (VCU), intravenous urography (IVU) and diuretic renography (DR).

RESULTS

At sonography 49 urinary tracts showed UUTWT. In 33, ipsilateral VUR could be demonstrated at VCU, 11 revealed obstruction at IVU and/or DR, and 4 showed non-obstructive pelvicalyceal dilatation at IVU and DR. In one patient, all imaging studies were normal. The positive predictive value of UUTWT for the presence of VUR was 67.4 % and for obstruction it was 22.5 %. Altogether, UUTWT indicated pathology in 98 % of urinary tracts.

CONCLUSION

After exclusion of urinary tract infection, urinary stone disease and prior renal transplantation, the most common associated findings in UUTWT are VUR and obstruction. Therefore, VCU seems to be justified in all cases of UUTWT. Nonrefluxing systems should be further evaluated with DR and/or IVU for exclusion of obstruction.

Ventriculoscopy-aided implantation of ventricular shunts in patients with hydrocephalus

Ventriculoscopy represents a new concept in the surgical treatment of children with hydrocephalus. Optimal catheter position can now be achieved with the help of a new method consisting of endoscopically controlled implantation of ventricular shunts. In addition, interventional ventriculoscopy enables or improves new operative procedures such as the fenestration of intracranial cysts or the removal of dislodged parts of catheter tips from the corresponding ventricle under direct optical control. Ventriculoscopy has been performed on 17 pediatric patients, with no complications to date.

Liver transplantation for hepatocellular carcinoma: results with preoperative chemoembolization

At the University of California, San Francisco, 17 patients who met the following criteria-hepatic tumor unresectable because of location or inadequate liver reserve, no metastases, HBsAg negative, no tumor larger than 5 cm in diameter, and no more than three tumors--were enrolled prospectively in a protocol employing preoperative chemoembolization to assess whether orthotopic liver transplantation (OLT) could cure a majority of highly selected patients with hepatocellular carcinoma (HCC). Thirteen patients had biopsy-proven HCC, 2 had the fibrolamellar variant, and 2 had radiological findings of HCC but no biopsy confirmation. Fourteen had underlying liver disease. All arteriographically apparent lesions were chemoembolized using a mixture including Gelfoam powder, doxorubicin, mitomycin-c, and cisplatin. Eight patients with poor hepatic reserve were chemoembolized when a donor organ became available, whereas 9 patients were chemoembolized and then placed on the waiting list. The only complication of chemoembolization was a gangrenous gallbladder in 1 patient. Thirteen patients underwent liver transplantation (2 patients without prior histological confirmation of carcinoma had no identifiable tumor at OLT); 3 patients developed metastases between the time of enrollment and donor organ availability and subsequently died; and 1 patient underwent a trisegmentectomy. Ten of the 11 patients with biopsy-proven HCC who underwent transplantation remain free of recurrent cancer at a median of 40 months; 1 patient died at 6 months of lymphoproliferative disease with no cancer found at autopsy. Although the role of chemoembolization is uncertain, these data show that the majority of carefully selected patients with HCC may achieve long-term survival with OLT.

Partial nephrectomy in well-responding stage I Wilms' tumors: report of three cases

We report on 3 of 21 stage I Wilms' tumor patients with tumor volumes of 190, 890, and 1300 mL, respectively, who responded dramatically to preoperative chemotherapy according to the Austrian/Hungarian Wilms' Tumor Study 89 by tumor volume reductions to 20%, 23%, and 13%, respectively. Radical resection of the tumors with renal preservation was achieved in all patients. Postoperative studies did not show any functional deficit in the preserved kidney. The patients have been in complete remission for 26, 33, and 60 months, respectively. Our preliminary results indicate that tumor resection should be feasible in patients with good responding stage I Wilms' tumors.

Amyloid goiter in a child with familial Mediterranean fever

A 7 year-old Turkish boy presented with a euthyroid goiter, which was noted during evaluation of familial Mediterranean fever. Amyloid deposits in the thyroid were found on fine-needle aspiration biopsy. Slight involution of the goiter within seven months may be attributed either to colchicine therapy or to treatment with levothyroxine and iodide.

[Color Doppler ultrasound in differential diagnosis of unilateral congenital cystic kidney abnormalities]

Doppler-sonography was performed in 16 newborns with prenatally diagnosed unilateral cystic renal malformation. 11 babies with multicystic dysplastic kidneys showed doppler-sonographically reduced systolic flow velocities and elevated resistive index (RI) [RI = 90-100%] or lack of obtainable perfusion signals. 4 of them had to undergo nephrectomy, the other asymptomatic patients could be managed conservatively, spontaneous regression could be observed. 5 other infants suffering from cystic nephroma, severe ureteropelvic junction obstruction, hudge bleeding of the adrenal gland and hydronephrosis due to ectopic ureter, having been prenatally presented as "cystic renal malformations", initially showed normal systolic flow velocities within renal parenchyma and only slightly elevated RI (mean = 83%). By this they could be differentiated from multicystic kidney dysplasia. We therefore propose to use doppler-sonography for differential diagnosis of prenatally assumed cystic kidney malformations.

Primary vesicoureteral reflux in infants with a dilated fetal urinary tract

Vesicoureteral reflux (VUR) was recognized neonatally by voiding cystography in 25 of 117 infants with a dilated fetal urinary tract. There was a male preponderance (76%) and a high percentage (40%) of associated urinary malformations. Thirty-nine refluxing units were studied. All grades of VUR were detected but gross dilating VUR dominated (59%). Spontaneous resolution was excellent in lower grades of VUR but was poor in gross VUR. Surgery was successfully performed in 13 renal units of nine patients with gross reflux, additional ipsilateral malformations, or pyelonephritis during antibiotic prophylaxis. Segmental renal scars developed in four kidneys after urinary infections, and a diffuse parenchymal lesion was noted in nine kidneys even at birth. One boy with duplication had a non-functioning refluxing system. Our results in a small number of infants show differences to children with VUR detected after urinary infections and seem to support the existence of a congenital reflux nephropathy.

[Which therapy is necessary for prenatally diagnosed multicystic kidney dysplasia?]

Multicystic dysplastic kidneys (MCD) were found in 17 of 114 neonates with prenatal diagnosis of urinary tract malformations. Distribution of side and of sex was not different. Contralateral malformations were present in 3 infants. One of them with contralateral renal dysplasia and cardiac malformation died at the age of 4 weeks. All other children so far have a normal renal function. Three neonates presented with a palpable abdominal mass, 2 infants had urinary infections during the first year of life. Two neonates had obstruction of the contralateral kidney caused by the giant MCD which relieved after nephrectomy. Hypertension or development of malignancy were not noted. Nephrectomy was performed in 10 infants at the mean age of 3.2 months. Six infants had conservative treatment and a complete regression was noted in 5 of them within a period of 8 to 18 months. Prenatal diagnosis of MCD enables early recognition of contralateral urinary malformations and of problems caused by the MCD itself. Conservative treatment is recommended in all asymptomatic patients. Studies of the natural history may show that regression of MCD is the rule and could account for many cases with apparent unilateral renal agenesis.

Scintigraphy and sonography in reflux nephropathy: a comparison

The evaluation of reflux nephropathy (RNP) is a major task in the following up of children with vesicoureteral reflux (VUR). Adequate monitoring of RNP development depends on the frequent use of sonographical and scintigraphical examinations. In order to evaluate the accuracy of sonography in monitoring RNP 63 patients suffering from VUR (mean age: 8.8 years, range: newborn to 18 years, male:female = 19:44) were examined prospectively. We calculated renal size sonographically and compared our data to static and dynamic renographic findings. Our results showed a good correlation between relative DMSA uptake and sonographically estimated relative renal size (r = 0.95, P < 0.001), whereas not unexpectedly the correlation between relative kidney function and sonographically estimated renal size was poor (r = 0.83, P < 0.01). We therefore believe, that in monitoring children with VUR, sonography can offer accurate information on questions about renal size and renal parenchymal structure as well as pelvic distention. With very small kidneys as well as with kidneys showing severe dilatation and above all for evaluating renal function, scintigraphy proved to be the better method.

Ultrasound and MRI findings in a case of childhood amyloid goiter

Goiter secondary to amyloidosis is rare in clinical practice and only a few descriptions of its radiologic features have been reported. We present the ultrasound and MRI findings of thyroid amyloidosis in a 7-year-old Turkish boy with familial Mediterranean fever.

Doppler sonography in congenital ureteropelvic junction obstruction and multicystic dysplastic kidneys

The accurate diagnosis of severe congenital ureteropelvic junction obstruction (UPJO) and the indications for surgical intervention are a matter of debate. Differential diagnosis from, for example, congenital cystic kidney malformations is important. In the present study we analysed the value of Doppler sonography (DS) for assessment of obstruction in congenital UPJO and its usefulness for differential diagnosis. A total of 138 infants and children were examined. Forty-three healthy infants and 24 children who had had a pyeloplasty at least 1 year previously served as control groups. Seventy-one children with UPJO and cystic kidney malformations underwent DS in addition to the usual examinations of intravenous urography and scintigraphy. Resistive Index (RI) was measured in both kidneys. Twenty infants showed decompensated UPJO and had needed an operation. Preoperatively all showed significantly increased RI (RI = 74%), which returned to normal after operation (RI = 68.3%). Thirty-nine children with UPJO could be managed conservatively, showing compensated obstruction on diuretic renography. On DS they had normal and symmetrical RI values (RI = 67%). Eleven children had multicystic dysplastic kidneys; 4 underwent nephrectomy. On DS all showed either absence of perfusion signals or very low flow velocities with very high RI values (RI = 90-100%) in the renal vessels. One child was found to be suffering from a cystic nephroma. DS was able to reveal quite normal vessel distribution in renal parenchyma with slightly elevated RI values (RI = 80%). Our results indicate that DS a non-invasive, non-ionising method of investigation, may serve as an additional functional parameter for defining accurately the degree of obstruction in UPJO.(ABSTRACT TRUNCATED AT 250 WORDS)

The role of sonography in the evaluation of gastro-oesophageal reflux--correlation to pH-metry

Sonography was compared to pH-metry and/or oesophagomanometry to evaluate the accuracy of sonography in the early diagnosis of gastro-oesophageal reflux. Thirty children with a mean age of 72 days (21-252 days) were studied. The results showed that specificity of sonographic diagnosis was 87.5% and sensitivity was 100% (with P less than 0.001). Sonography also proved helpful in providing both functional and morphological data in addition to pH-metric results. This study therefore suggests that sonography is useful as the first approach in the diagnosis of vomiting babies as it is non-invasive and provides sufficient diagnostic accuracy.

[Prenatal diagnosis of primary megaureter]

22 of 114 infants with prenatal diagnosis of urinary tract malformations (15 boys) had obstruction of the ureterovesical junction caused by primary megaureter (n = 14), ureterocele (n = 7), or ectopic ureter (n = 1). Infants with infravesical obstruction or refluxing systems were excluded. All infants had a normal renal function and probably only 5 of them (23%) would have been diagnosed during infancy without prenatal diagnosis. A total number of 26 renal units was evaluated. Six infants had ipsilateral duplication with additional contralateral duplication (n = 2) or vesicoureteric reflux (n = 2). A nonfunctioning kidney or upper pole of duplication was noted in 7 units (5 with ureteroceles); in two instances a moderately dysplastic kidney was present. One boy with urinary infections developed renal scarring during follow-up. Conservative treatment was performed in 14 renal units while 12 units of 11 children had 22 operations (9 temporary diversions) at a mean age of 4,6 months. A severe operative complication was noted in one infant. Conservative treatment is justified in many infants with primary obstructive megaureters but severe renal dysplasia may be present even neonatally. Yet we feel that prenatal diagnosis benefitted most infants, especially those with the most severe malformations.

Storage material from urine and tissues in the nephropathic phenotype of infantile sialic acid storage disease

We analysed urine and tissue specimens from two nephrotic infantile sialic acid storage disease patients (nISSD) for free and bound sialic acids in comparison to non-nephrotic ISSD patients (ISSD), patients with minimal change nephrosis (nControl) and normal controls (Control). No differences in the excretion of urinary free sialic acid could be detected between ISSD and nISSD urines. Sialyloligosaccharide fractions were only slightly elevated and of apparently normal composition. Owing to glomerular dysfunction, measurable quantities of protein-bound sialic acids were present in nISSD and nControl. In nISSD tissues, free sialic acid was elevated 18-100-fold above control and 3-12-fold above Niemann-Pick A (NPA) samples. The storage of membrane-bound sialic acid was slightly increased compared to control tissues, but equal to those from NPA, thus reflecting an unspecific increase of membranes due to lysosomal storage. According to these results no major biochemical differences were detectable between ISSD and nISSD. The nephrotic syndrome in nISSD could not be related to a general deficit in the sialylation of glycoproteins. Nevertheless, a cell membrane-specific alteration in sialoglycoproteins of glomerular cells might still be possible.

Amniotic fluid N-acetyl-beta-D-glucosaminidase activity and renal abnormalities

Amniotic fluid N-acetyl-beta-D-glucosaminidase (NAG) activity was measured in 21 normal pregnancies to determine reference values, and in 10 pregnancies with fetuses who had prenatally recognised renal and urinary tract malformations. The normal values obtained at 17-19 and 28-31 gestational weeks did not differ, and an activity of 105 units NAG/mmol creatinine was the upper limit of the normal range. Raised NAG activities were found in four fetuses with oligohydramnios and severe bilateral renal disease, and also in two infants with a normal amount of amniotic fluid, only unilateral renal lesions, and a normal renal function after birth. Three of four cases with normal NAG activities had malformations without kidney damage, but one baby with prune belly syndrome was subsequently found to have dysplastic kidneys and renal failure. Our preliminary results suggest that a high level of NAG activity in the amniotic fluid indicates unilateral or bilateral kidney damage but is not proof of intrauterine renal failure.

[Ultrasonography in urinary tract infection in infancy]

In a prospective study 77 infants (35 boys) with a mean age of 5.23 months were studied to determine the value of sonography for detection of renal parenchymal involvement in urinary tract infection (UTI). Sonography was performed during UTI and about one month later. UTI was classified as upper and lower UTI according to the clinical and laboratory findings; radiological investigations (voiding cystoureterography = MCU) were performed in all infants. 40 infants were classified to have upper UTI. There was a high sensitivity (80%) and specificity (97%) for detection of renal involvement by sonography. Incidence for vesicoureteral reflux (VUR) was significantly higher in infants with repeated pathological findings on sonography. In contrast, no VUR was detected on MCU in all 12 infants with normal findings in both sonographic examinations. Yet, sonography without catheterization could not detect VUR in all infants with radiologically confirmed reflux. Our results show, that sonography is of definite value in infants with UTI, but cannot replace radiological work up.

Five years experience with continuous extracorporeal renal support in paediatric intensive care

Continuous arterio-venous haemofiltration (CAVH) and continuous veno-venous haemofiltration (CVVH) were used as renal support in 52 critically ill infants and children with acute renal failure. The majority of the patients were on mechanical ventilation (90%) and needed vasopressor support (85%). Uraemia was satisfactorily controlled with both treatment modes. Post-treatment serum urea levels were not different between survivors (94 +/- 8.8 mg/dl) and non-survivors (99.5 +/- 8.8 mg/dl). There were significant differences between survivors and non-survivors in the mean arterial pressure (64.7 +/- 3.8 vs 48.0 +/- 2.2 mmHg, p less than 0.001), the number of organ system failures (2.9 +/- 0.16 vs 3.8 +/- 0.21, p less than 0.025), and the severity of illness assessed by the acute physiologic score for children (APSC 19.4 +/- 1.9 vs 26.3 +/- 1.9, p less than 0.01). The overall mortality was 48%. The mortality in the CVVH group (65%) was higher than in the CAVH group (40%). Death was significantly related to sepsis (p less than 0.005) and multiple system organ failure (p less than 0.005). A major complication during CAVH was one femoral artery thrombosis after 12 days of treatment. Technical problems were only observed during CVVH. CAVH and CVVH are safe and effective methods of continuous renal support for critically ill paediatric patients with multiple system organ failure. CAVH is simpler, needs no specially trained staff and seems to the ideal renal replacement system for critically ill infants.

[Therapy and prognosis of children with prenatally diagnosed urinary tract abnormalities]

Urinary tract malformations are recognized already prenatally to an increasing extent, but the indications for, and the time of surgical intervention are still a matter of debate. The present study is an analysis of the data collected over an 80-month period of 76 patients whose urinary tract malformation was suspected prenatally and confirmed after birth. Patients with lethal malformations whose disease led to abortion or intrauterine death were excluded. Ureteropelvic junction obstruction was present in 47% of the patients and obstructive uropathy accounted for 67% of all malformations. In contrast, vesicoureteric reflux was found only in eight patients. Thirty seven infants (49%) required surgical intervention and 61% of all operations were performed during the first month of life. 57% of these early interventions were temporary diversions. The indication for surgical treatment was based on sonographic and radiological assessment of the malformation and on the results of functional assessment. In many instances surgery was delayed until indicated on the basis of the findings of the follow-up studies. All reconstruction operations were successful. Prenatal diagnosis benefitted most children, especially those with the most severe malformations. No patient died as a result of the renal condition and the prognosis is grave in only one child, who is likely to go into terminal renal failure in childhood.

[Familial hypophosphatemia]

The main features of X-linked dominant renal hypophosphatemic rickets are illustrated in this study of two patients who presented with rickets, deformities of the lower limbs, and small stature. Hypophosphatemia secondary to a reduction in renal tubular reabsorption of phosphate and a defect of vitamin D hydroxylation are the hallmarks of the disease. The best measure of renal handling of phosphate is to determine the tubular maximum of phosphate transport normalized for glomerular filtration rate (TmPO4/GFR). Determination of the calcium/creatinine ratio of a random urine sample proved to be a good additional parameter to control supplementation of phosphate and calcitriol. Diagnosis of the disease in our two patients enabled us to recognize renal hypophosphatemic rickets in both mothers and in two further ancestors of one patient. Both mothers suffered from early arthrosis.

Continuous arteriovenous hemofiltration in premature infants

Five critically ill premature infants with acute renal failure (ARF) and hypervolemia were treated by continuous arteriovenous hemofiltration (CAVH). Prostacyclin was used to prevent hemofilter clotting. Mean treatment duration was 53.6 +/- 14 h. Mean blood flow rates of 1.6 +/- 0.22 ml/min and filtration fractions of 17.2 +/- 3.7% produced mean ultrafiltration rates of 8.3 +/- 3.1 ml/kg.h. Fluid overload was easily corrected by means of CAVH. The mean prehemofiltration serum creatinine and urea levels were 2.3 +/- 0.4 and 77 +/- 29.7 mg/dl; the mean posthemofiltration levels were 2.38 +/- 0.43 and 92 +/- 34.4 mg/dl, respectively. Hemofilter clotting occurred every 14 h. Urinary output was restored in three infants. Three of the five infants died, but none of the deaths was related to ARF or CAVH. CAVH is a safe and simple method to control fluid and metabolic imbalances in critically ill premature infants.

[The value of prenatal ultrasound screening exemplified by abnormalities of the urogenital system. Data from the Styrian malformation register 1985 to 1987]

Over a three-year period (1985 to 1987), the number of fetal malformations was entered into Styrian Malformation Register (SMR). The data were compared with those of the Austrian Ministry of Health. The SMR collected 137 cases of urinary tract malformations, but only six appeared in the Health Ministry statistics. This discrepancy resulted from the different data collection methods. Presently only a small percentage of fetal abnormalities is officially registered. Using the example of urinary tract malformations this paper shows the value of prenatal ultrasound screening. Such infants must be treated soon after delivery to avoid progression of parenchymal damage. Ultrasound examinations should not be restricted to pregnant women at defined risk. Registration of all prenatally diagnosed--or missed--malformations is a quality-control measurement and improves prenatal diagnosis.