Early diagnosis of solitary functioning kidney: comparing the prognosis of kidney agenesis and multicystic dysplastic kidney.

BACKGROUND: Individuals with congenital solitary functioning kidney (SFK) are at an increased risk of kidney damage. According to some studies, the risk is higher in unilateral kidney agenesis (UKA) than in unilateral multicystic dysplastic kidney (UMCDK). We hypothesized that with early detection of children with UKA and UMCDK, there would be no difference in the presence of hypertension, proteinuria, and reduced glomerular filtration rate (GFR) between UKA and UMCDK. METHODS: Based on a long-term follow-up protocol, we evaluated a cohort of 160 children followed from birth for SFK (84 with UKA and 76 with UMCDK) detected by prenatal or routine neonatal ultrasound screening. Hypertension, proteinuria, and reduced GFR were monitored as markers of kidney damage. We compared the characteristics and outcomes of the subgroups of children with UKA and UMCDK. RESULTS: GFR was reduced in 42 (26.2%) children, of whom 41 showed only mild reduction. Hypertension and proteinuria were found in 22 (13.8%) and 14 (8.8%) children, respectively. Combined kidney damage was present in 57 (35.6%) children. The UMCDK and UKA subgroups differed in GFR at final examination, with UMCDK patients being significantly more likely to have normal GFR compared to UKA patients (82% vs. 67%; p = 0.039). CONCLUSIONS: One third of the children showed signs of SFK damage, albeit mild. Patients with UKA had reduced GFR significantly more often than those with UMCDK, but did not differ in the rates of hyperfiltration injury or congenital anomalies of the kidneys and urinary tract (CAKUT) in SFK.

Renal parenchymal thickness in children with solitary functioning kidney.

BACKGROUND: Reduced renal parenchymal thickness (PT) is a parameter used by clinicians to assess the degree of hydronephrosis. In patients with a congenital hydronephrotic solitary functioning kidney (SFK), PT is difficult to determine as there is no comparison with the contralateral kidney. The aim of this study was to obtain ultrasound measurements of PT in children with normal SFK and to compare these data with PT measurements in children with two functioning kidneys. METHODS: This was a prospective multicenter study carried out between 2006 and 2011 in which 236 children aged 11 days to 18.96 years with healthy SFK were examined. The SFK etiologies were unilateral renal agenesis or a nonfunctioning contralateral kidney, mostly due to multicystic dysplasia. In addition to determining other parameters, we measured PT in the middle third of the kidney by ultrasound. Correlations between PT and age, height and weight were assessed. RESULTS: Correlation analysis showed a positive correlation with renal PT for all parameters. The correlation coefficients for age, height and weight were 0.863, 0.873 and 0.874, respectively. In most age categories, the renal parenchyma was significantly thicker in the SFK than in two functioning kidneys. CONCLUSIONS: Based on our results, we suggest that PT in the SFK is correlated with height, weight and age of the patient. Consequently, measurements of PT may be used for monitoring the development of the healthy SFK and may contribute to a more accurate assessment of the severity of SFK anomalies.

The use of biomarkers in the diagnosis and treatment of obstruction of the upper urinary tract in children.

Antenatal hydronephrosis, dilatation of the upper urinary tract (UUTD), is a common finding on prenatal ultrasound. One of the most common causes is ureteropelvic junction (UPJ) obstruction. Although such prenatally diagnosed UUTD resolves spontaneously in most newborns, further examination of these children is advocated to prevent possible irreversible kidney damage, and ultrasound is mainly used for this. If the dilatation persists or becomes symptomatic, it is necessary to proceed to other relatively demanding and invasive diagnostic examinations for these small patients, where the question of the right timing of indications for possible surgical solutions is still unclear. For this reason, various biomarkers have been investigated in a number of clinical trials as potential mini-invasive diagnostic tools for determining when upper urinary tract dilatation in such children poses a threat to the developing kidneys and they should be operated on, and vice versa, when to proceed conservatively. The aim of this article is to review the findings on and current issues with the use of biomarkers in the diagnosis and treatment of UPJ obstruction in children.

Diagnostic accuracy of postnatal ultrasound screening for urinary tract abnormalities.

The study was aimed at (1) the determination of the incidence of abnormalities of the urinary tract in newborn infants detected by postnatal ultrasound screening, and (2) the evaluation of the diagnostic accuracy of postnatal ultrasound screening for detecting surgical urinary tract abnormalities. The prospective study was of full-term neonates born in the University Hospital of Olomouc in 2005-2008 who underwent renal ultrasound screening after 72 h of life. Significant findings were recorded. Subsequent diagnostic and therapeutic procedures were recorded and evaluated in a group of children with detected renal pelvic dilatation (RPD). (1) A total of 6,088 newborn infants was examined. The absolute and relative RPD incidence rates (anteroposterior diameter, APD) were as follows: 5-7 mm, 146 (2.4%); 7-10 mm, 70 (1.15%); 10-15 mm, 13 (0.21%), and 15 mm or more, 5 (0.08%). Of those, 16 children were operated on for abnormalities of the urinary tract, of which nine (56%) had been detected by prenatal screening. Other findings: six cases of unilateral renal agenesis, four cases of multicystic renal dysplasia, four of renal dystopia, one of polycystic kidney disease and one of renal hypoplasia. (2) A group of 224 children with postnatally detected RPD was examined, of whom 40 (17.9%) underwent voiding cystourethrography and/or scintigraphy and 16 (7.1%) were treated surgically. The receiver operating characteristic curves were analyzed, and the areas under the curves were calculated. Postnatal renal ultrasound screening is probably a suitable test for detecting significant urinary tract abnormalities.

Single injection paravertebral block for renal surgery in children.

BACKGROUND: Continuous paravertebral block (PVB) has been successfully used for postoperative analgesia in children. However, data regarding the efficacy of a single injection technique for major renal surgery are still lacking. METHODS: Following the ethics committee approval and parent informed consent, 24 children (median 10.3 months; range: 2.9-26.8) undergoing major renal surgery were included in a prospective observational pilot study. Following a standardized general anesthetic the patients were administered a single injection low thoracic PVB (loss-of-resistance technique; 0.5 ml.kg(-1) of levobupivacaine 2.5 mg.ml(-1) with epinephrine 5 mug.ml(-1)) at the end of surgery. Postoperative pain was assessed by Face, Legs, Activity, Cry, Consolability (FLACC) score at predetermined time points and in case of apparent patients' discomfort during the first 12 postoperative hours. The duration of postoperative analgesia was defined as the interval between PVB and the first supplemental administration of a rescue opioid analgesic. The incidence of complications and postoperative vomiting (POV) was also recorded. RESULTS: A successful PVB was achieved in 23/24 patients (95.8%). The median duration of the block was 600 min (range: 180-720 min) with 10 children not requiring any supplemental analgesia during the 12-h observation period. Vascular puncture was observed in 2/24 children (8.3%) and POV occurred in 4/24 children (16.7%). All complications were considered minor and did not influence recovery. CONCLUSIONS: Single injection PVB provided clinically relevant postoperative analgesia in children undergoing major renal surgery.

New hybrid procedures in treating occluded arteriovenous hemodialysis grafts.

BACKROUND: The use of arteriovenous graft is indicated in patients if the subcutaneous venous bed is exhausted or unsuitable for arteriovenous fistula creation. The leading cause of failure of a prosthetic arteriovenous hemodialysis-access graft is venous anastomotic stenosis causing thrombosis of the graft. A number of surgical techniques and endovascular tools have been used to treat this stenosis and thrombosis. None have yet proven to be ideal. This study was designed to evaluate the results of hybrid treatment of arteriovenous graft thrombosis associated with venous anastomotic stenosis. METHODS: Over the period 2013-2014, we treated 16 AVG occlusions. Immediately after the diagnosis of occlusion was made, the patients underwent thrombectomy using a Fogarty catheter. After thrombectomy, a diagnostic fistulogram was performed and if VAG stenosis was confirmed, it was treated with balloon angioplasty and stent graft introduction. Lesions were dilated to reduce the stenosis in the treated area to less than 25%. RESULTS: Primary patency after 12 months was 32.8%. Primary assisted patency was 44.7%, secondary patency was 47.6%. Restenosis of the stent graft was seen in two patients. Recurring AVG occlusion was observed in four patients. The average number of interventions to maintain AVG patency was 1.18 per patient/1 year of dialysis. CONCLUSION: Treatment of AVG thrombosis due to VAG stenosis by hybrid procedure proved to be effective and improved secondary patency.

High-grade urothelial bladder cancer in children: A case report and critical analysis of the literature.

BACKGROUND: Bladder cancer is relatively common in adults. In children, it is extremely rare and in the majority of cases, low grade, low stage urothelial cancers are found. CASE REPORT: We describe the diagnostic, therapeutic, and follow-up management of bladder cancer in a 3-year-old boy examined for painless hematuria. Transurethral resection of the tumor was performed and T1 high grade urothelial cancer with osseous metaplasia was found in definitive specimens. During the 2-year follow-up, there has been no recurrence. Typical characteristics of the most prevalent bladder tumors are presented. CONCLUSION: Despite its low incidence and low prevalence bladder cancer in children is a very serious condition which must not be missed in the differential diagnosis of hematuria or urinary tract infection. It is vital to differentiate urothelial cancer from hamartoma and nephrogenic adenoma and, particularly in osseous metaplasia, from sarcomatoid carcinoma. Especially in high-grade cancers, precise TUR of the tumor with a careful follow-up is essential to detect cancer recurrence and reduce progression.

Can renal ultrasonography and DMSA scintigraphy be used for the prediction of irreversible histological lesions of the upper pole in duplex system with ureteroceles or ectopic ureters?

AIM: To assess of the role of renal ultrasonography (US) and DMSA renal scintigraphy in the prediction of irreversible histological lesions of the upper pole in duplex system. METHODS: A prospective cohort study based on data collected between 2005 and 2012 at our institution. The cohort consisted of 23 patients with ureteroceles and 28 patients with ectopic ureters who underwent upper pole nephrectomy. Preoperative recordings from ultrasound and nuclear renal scans were compared with the histological findings. Histological irreversible lesions were defined as the presence of dysplasia and/or severe chronic interstitial nephritis (CIN) in ≥ 90% of the specimen. ROC (Receiver Operating Characteristic) curves were used to investigate thresholds in order to identify irreversible lesions using various differential functions. The histology was correlated with the results of imaging. RESULTS: Pathological findings were found in all histological samples. Histological lesions were irreversible in 20/23 patients (87.0%) with ureteroceles and in 14/28 patients (50.0%) with ectopic ureters. The model is able to predict irreversible lesions if an upper pole differential function is ≤ 3% in patients with ureteroceles, and ≤ 2% in the presence of ectopic ureters. Weak association between parenchymal thinning on ultrasonography and irreversible lesions was found in patients with ectopic ureters. CONCLUSION: DMSA renal scintigraphy provides a useful tool for the prediction of irreversible lesions in the upper pole. Low differential function (≤ 3% and ≤ 2%, respectively) indicates irreversible lesions, favoring heminephrectomy. Higher differential function indicates greater remaining biological potential of the parenchyma, favoring reconstruction of the upper pole.

Outcomes of adrenalectomy in patients with primary hyperaldosteronism--a single centre experience.

INTRODUCTION: Primary hyperaldosteronism is a common cause of secondary hypertension. In patients with proven unilateral overproduction of aldosterone adrenalectomy can cure hyperaldosteronism with high probability and a positive effect on hypertension. The aim of the study was to determine the effects of unilateral adrenalectomy on blood pressure and laboratory parameters. The secondary objective was to identify parameters that would allow the prediction of hypertension cure. METHODS: We performed a cross-sectional analysis of the data of patients who underwent unilateral adrenalectomy for primary aldosteronism at the Department of Urology of University Hospital Olomouc in the years 2000-2011. We assesed the preoperative clinical conditions of patients, the results of biochemical and radiological examinations, course of the surgery and post-operative course including laboratory and clinical parameters during the 12 months postoperatively. RESULTS: 62 patients underwent adrenalectomy for primary aldosteronism in this period. Four patients were excluded from the study due to surprising histology (myelolipoma in 2, carcinoma in 2), seven patients had incomplete postoperative data. The statistical analysis therefore included 51 patients, of which 57% were females. CT or MRI was performed in all patients; 63% patients underwent superselective catheterization of adrenal veins (AVS). Adrenalectomy was performed in all cases laparoscopically. Histology most often showed adrenal hyperplasia (59%), adenoma was detected in 37% and adenoma on the basis of micronodular hyperplasia in 4%. Twelve months after surgery the antihypertensive drugs were discontinued in 17/51 (33%) and the number or dose of antihypertensive drugs was reduced in 25/51 (49%). Normokalemia and normalisation of the aldosterone-renin ratio (ARR) was detected in 92% and 84% of the patients. Performing AVS did not statistically significantly influence the rate of blood pressure control or normalization of ARR, which is probably due to small study size. This study demonstrated a better effect of surgery on blood pressure in younger patients. CONCLUSIONS: Unilateral adrenalectomy had a positive effect in 82% of the patients operated for primary aldosteronism and lead to either blood pressure normalization or reduction of the antihypertensive medication.