Rare case with plethora of upper urinary tract anomalies associated with pelviureteric junction obstruction: a surgical challenge managed with robot assistance.

The genitourinary system for reasons unknown is more likely to have birth defects than any other system. The anomaly of collecting system draining the kidney represent mystifying subset of congenital anomalies. Pelviureteric junction obstruction (PUJO) is most common. Chronic obstruction can lead to stasis, urinary infection and stone formation in PUJO. Extrarenal calyces, which is characterised by presence of calyces and renal pelvis outside the renal parenchyma is one of the rare anomalies seen among the collecting system right gonadal vein drains into inferior vena cava. Its altered drainage into right renal vein is rarely seen and reported. Glut of these multiple anomalies in a single case is an extremely rare event. We hereby discuss a case of 40-year-old male patient with combination of all these anomalies and discuss the embryology, presentation and management.

Neuronal defects an etiological factor in congenital pelviureteric junction obstruction?

INTRODUCTION: Congenital pelviureteric junction obstruction (PUJO) is one of the most frequent causes of neonatal hydronephrosis. Obstruction at the PUJ has potential severe adverse outcomes, such as renal damage. While pyeloplasty has been established as the definitive treatment, the exact pathophysiology of congenital PUJO remains unknown. Recent research has proposed neuronal innervation defects as an etiological factor in congenital PUJO. We aim to study the expression of various neuronal markers in PUJO specimens compared with controls, and evaluate whether severity of renal disease or dysfunction pre-operatively is related to expression of neuronal markers in resected PUJO specimens. MATERIALS AND METHODS: All consecutive patients who underwent dismembered pyeloplasty at KK Women's and Children's Hospital, Singapore, for intrinsic PUJO from 2008 to 2012 were included. Patients with other co-occurring renal pathologies were excluded. Controls were obtained from nephrectomy patients with Wilm's tumor or other benign renal conditions during the same period. Specimens were stained immunohistochemically with neuronal markers protein gene product 9.5 (PGP9.5), synaptophysin, and S-100, and with CD-117, a marker for interstitial cells of Cajal (Table). Levels of expression of the markers were assessed semiquantitatively (decreased, increased or no change) in comparison with controls by two independent observers. Pre-operative data of patients' renal anatomical (ultrasonography measurements of renal pelvis size) and functional parameters (differential renal function measured using MAG-3 renal scans) were obtained. DISCUSSION: Thirty-eight PUJO specimens (38 renal units) and 20 controls were studied. Mean patient age at pyeloplasty was 25.3 months (2.9-167.6 months). Median pre-operative pelvic size was 25.0 mm (17.0-50.0 mm). Both PUJO specimens and controls showed great heterogeneity in distribution of innervation. All four immunohistochemical markers were not predictive of significant pre-operative renal pelvis dilation or pre-operative diminished renal function of the operated kidney. CONCLUSIONS: There exists marked variability in expression of neuronal markers synaptophysin, PGP9.5, and S-100, and CD-117 in PUJO specimens compared with controls. Our results show no clinical significance of the expression of neuronal markers in predicting degree of pre-operative renal pelvis dilation or differential renal function. The heterogeneity of expression of neuronal markers in PUJO specimens and controls in our population is at variance with prior studies. The etiology of PUJO is likely to be complex and multifactorial.

LDL Receptor-Related Protein 6 Modulates Ret Proto-Oncogene Signaling in Renal Development and Cystic Dysplasia.

Hypoplastic and/or cystic kidneys have been found in both LDL receptor-related protein 6 (Lrp6)- and ß-catenin-mutant mouse embryos, and these proteins are key molecules for Wnt signaling. However, the underlying mechanisms of Lrp6/ß-catenin signaling in renal development and cystic formation remain poorly understood. In this study, we found evidence that diminished cell proliferation and increased apoptosis occur before cystic dysplasia in the renal primordia of Lrp6-deficient mouse embryos. The expression of Ret proto-oncogene (Ret), a critical receptor for the growth factor glial cell line-derived neurotrophic factor (GDNF), which is required for early nephrogenesis, was dramatically diminished in the mutant renal primordia. The activities of other representative nephrogenic genes, including Lim1, Pax2, Pax8, GDNF, and Wnt11, were subsequently diminished in the mutant renal primordia. Molecular biology experiments demonstrated that Ret is a novel transcriptional target of Wnt/ß-catenin signaling. Wnt agonist lithium promoted Ret expression in vitro and in vivo. Furthermore, Lrp6-knockdown or lithium treatment in vitro led to downregulation or upregulation, respectively, of the phosphorylated mitogen-activated protein kinases 1 and 3, which act downstream of GDNF/Ret signaling. Mice with single and double mutations of Lrp6 and Ret were perinatal lethal and demonstrated gene dosage-dependent effects on the severity of renal hypoplasia during embryogenesis. Taken together, these results suggest that Lrp6-mediated Wnt/ß-catenin signaling modulates or interacts with a signaling network consisting of Ret cascades and related nephrogenic factors for renal development, and the disruption of these genes or signaling activities may cause a spectrum of hypoplastic and cystic kidney disorders.

Update on Multicystic Dysplastic Kidney.

Multicystic dysplastic kidney (MCDK) is the most common cause of cystic disease in children. It is characterized by multiple non-communicating cysts of varying sizes with no identifiable normal renal parenchyma. The incidence ranges from 1 in 1000 to 4300 live births, and it is one of the most commonly detected anomalies on prenatal ultrasound. MCDK has been shown to follow a benign course with relatively few sequelae and therefore should be managed conservatively. Currently, the key clinical questions revolve around the detection of anomalies in the contralateral kidney and follow-up imaging. The recent literature suggests that very limited radiographic evaluation of the MCDK is needed. The use of voiding cystourethrogram or nuclear medicine renal scans should be directed by any abnormalities on renal ultrasound or the development of urinary tract infections.

URETERIC ANGIOMYOLIPOMA CAUSING UNILATERAL PELVI-URETERIC JUNCTION OBSTRUCTION.

A 63-year-old lady, presented to us with nonspecific abdominal pain. Ultrasonography (USG) and CT scan abdomen and pelvis, showed right moderate hydronephrosis, with no evidence of mass at pelvi-ureteric junction (PUJ) obstruction. Per-operatively mass upper ureter was found obstructing PUJ. Mass was excised and pyeloplasty done, with Double J (DJ) Stenting. Stent was removed after a week. Histopathology of specimen showed upper ureteric Angiomyolipoma.

Laparoscopic Transposition of Lower Pole Crossing Vessels (Vascular Hitch) in Children with Pelviureteric Junction Obstruction: How to Be Sure of the Success of the Procedure?

BACKGROUND: To report a series of children with pelviureteric junction obstruction (PUJO) due to lower polar crossing vessels who underwent laparoscopic vascular transposition. In order to confirm the relief of the obstruction and avoid unnecessary additional procedures, we suggest performing an intraoperative measure of the ureteral opening pressure. PATIENTS AND METHODS: From January 2007 and January 2014, 11 children underwent laparoscopy to treat well-documented PUJO by polar vessels. In the first 7 cases, children underwent a careful dissection of the polar vessels that were transposed cranially in the pelvis. In the last 4 cases, a percutaneous needle was inserted into the renal pelvis, and the ureteral opening pressure was obtained intraoperatively, before and after the vascular hitch procedure, in 3 cases. No vascular relocation was necessary except in 1 case with a polar vessel unrelated to the obstruction. RESULTS: The laparoscopic procedure was feasible in all cases. Median operative time was 90 minutes without intraoperative complications. In the last 3 cases, a decrease in the renal pelvic pressure was demonstrated just after releasing the ureter from the polar vessels, confirming the extrinsic obstruction. In 1 case, the intraoperative pelvic pressure measurement showed that there was no vascular compression but that obstruction was due to renal rotation. During follow-up (range, 12-96 months) all patients reported resolution of their symptoms, nine children showed a decrease in the hydronephrosis grade, and all but one with poor function had improved drainage on diuretic renography. CONCLUSIONS: Intraoperative measurement of ureteral opening pressure may help to confirm that the vascular hitch procedure has relieved the pelvic obstruction, precluding the need for dismembered procedures. We believe that in some doubtful cases, with the addition of intraoperative pelvic pressure measurement, vascular hitch may be considered a safe procedure to treat selected cases of PUJO in children.

[Diagnosis and treatment of ureteropelvic junction obstruction caused by renal crossing vessels:an analysis of 24 cases].

OBJECTIVE: To investigate the diagnosis, treatment and surgical outcomes of ureteropelvic junction obstruction (UPJO) caused by renal crossing vessels. METHODS: The case records of 24 patients discharged from Peking University Third Hospital between June 2001 and September 2011 with the diagnosis of UPJO caused by renal crossing vessels were reviewed .Of the 24 patients, 17 were male and 7 were female patients. The mean age was 28 years (range, 2-63 years). The mean disease duration was 22.3 months (range, 7 days to 180 months). Of which, 4 patients underwent open surgery, and the other 20 patients were treated with laparoscopic surgery. Surgical approach was decided by operative conditions: adhesion release technique, dismembered pyeloplasty or Y-V anastomosisor, with or without cut off the crossing vessels. The kind of crossing vessels was recorded, and the effect of surgery was evaluated by follow-up. RESULTS: Fifteen cases were caused by oppressed renal crossing artery, 8 cases by renal crossing vein, and 1 case by 2 renal crossing arteries and 1 renal crossing vein. Among them, 11 cases were followed up successfully. Average follow-up time was 48.2 months (range, 13-120 months). Eight cases (8/11) were relieved, and 1 case (1/11) had no obvious improvement, another 2 cases (2/11) were aggravating. Among those 6 cases underwent adhesion release technique, 3 cases were relieved, 1 case had no obvious improvement, and 2 cases were aggravating. Five cases who underwent dismembered pyeloplasty was relieved significantly. CONCLUSIONS: Renal crossing artery is one of the main causes of UPJO, the crossing artery should be retained as far as possible. Crossing vessel oppression is not the only pathological cause of UPJO, so the treatment of UPJ constriction is also very important. Dismembered pyeloplasty seems to be the most efficacies treatment procedure for UPJO caused by repressed vessels, and the remission rate of adhesion release technique seems limited.

The natural history of the multicystic dysplastic kidney--is limited follow-up warranted?

OBJECTIVE: Imaging of patients with multicystic dysplastic kidney (MCDK) has increased over the past three decades. This increased use of imaging has provided additional insights into the natural history of MCDK. The present study looked at this data for predictors of involution and associated anomalies. METHODS AND MATERIALS: Institutional review board approval was obtained for this retrospective study. The University of Michigan Departments of Urology and Radiology records were searched to identify unilateral MCDK patients during 1980-2012. Available clinical, radiological and surgical records were reviewed, and pertinent data were recorded. The log-rank test and a Cox proportional regression analysis were performed to identify predictors of MCDK involution. Probability of involution over time was assessed using Kaplan-Meier methodology. RESULTS: 301 unilateral MCDKs were identified; 195 (64.8%) were detected antenatally. Of the MCDKs found, 136 (45.2%) were in girls; 160 (53.2%) were right-sided. Mean size at baseline was 5.0 ± 0.2 cm (Mean ± SE). Associated abnormalities included: contralateral ureteropelvic junction obstruction (n = 10; 3.3%); contralateral ureterovesical junction obstruction/primary megaureter (n = 6; 2.0%); ipsilateral VUR (n = 21; 7.0%); contralateral VUR (n = 63; 20.1%); and renal fusion anomaly (n = 4; 1.3%). The cumulative probability of involution was: 9.8% at one year, 38.5% at five years, and 53.5% at ten years of age. Baseline MCDK size was the only significant predictor of involution at bivariate (p < 0.0001) and multivariate (p < 0.0001; HR 0.58 [95% CI: 0.49, 0.69]) analyses. No MCDK developed malignancy during the follow-up period. CONCLUSION: As many MCDKs eventually involute and the risk of associated malignancy appears to be very low, there is no absolute indication for nephrectomy. Based on the data and other recent studies, it is believed that pediatric MCDK patients with no other urologic abnormalities can safely tolerate more limited urological and radiological follow-up.

Joubert syndrome presenting as unilateral dysplastic kidney, hypotonia, and respiratory problem.

An 8-month-old girl with a history of asphyxia and respiratory distress immediately after birth was hospitalized at her fourth month of age with the diagnosis of kidney infection and it was revealed that she had a unilateral multicystic dysplastic kidney. In recent admission, she presented to emergency room with fever, hyperpnea, and apnea. In appearance, she was a hypotonic girl with broad forehead, hypertelorism, depressed nasal bridge and bitemporal regions, rapid vertical and horizontal nystagmus, and open mouth with salivation. In spite of normal physical growth, she had delayed developmental milestones. Blood gas O 2 saturation dropped after she received phenobarbital. Her urinary and blood tests were normal; however, her cranial magnetic resonance imaging (MRI) revealed vermis agenesis and molar tooth sign. These physical and para-clinical findings suggested Joubert syndrome.

Management and etiology of the unilateral multicystic dysplastic kidney: a review.

In children, unilateral multicystic dysplastic kidney (MCDK) is one of the most frequently identified urinary tract abnormalities. A variety of proposed etiologies has been associated with the underlying pathogenesis of MCDK. These include genetic disturbances, teratogens, in utero infections, and urinary outflow tract obstruction. From 5-43% of the time, MCDK has associated genito-urinary anomalies, both structural and functional in nature. A review of the literature reveals that involution rates are reported to be 19-73%, compensatory hypertrophy of the contralateral kidney occurs from 24-81% of the time, and estimated glomerular filtration rates (GFRs) (by the Schwartz formula) range from 86-122 ml/min per 1.73 m(2) body surface area. Most authors suggest serial ultrasonography to monitor contralateral growth, routine blood pressure monitoring, and a serum creatinine monitoring algorithm. The risk of hypertension in those with MCDKs does not appear to be greater than that of the general population, and the rates of malignant transformation of MCDK are small, if at all increased, in comparison with those in the general population. If the patient develops a urinary tract infection or has abnormalities of the contralateral kidney, shown on ultrasound, a voiding cystourethrogram is recommended. Finally, the body of literature does not support the routine surgical removal of MCDKs.

"Multicystic dysplastic kidney (Potter type II syndrome) and agenesis of corpus callosum (ACC) in two consecutive pregnancies: a possible teratogenic effect of electromagnetic exposure in utero".

Agenesis of the corpus callosum is found in about 5 per 1,000 births and it is due to maldevelopment or, secondary, to destructive lesions. Multicystic dysplastic kidneys is a consequence of either developmental failure of the mesonephric blastema to form nephrons or to early urinary obstruction due to urethral or ureteric atresia and can be found in about 1 per 1,000 live births. A case of fetal multicystic dysplastic kidney disease (Potter type II syndrome) and complete agenesis of the corpus callosum demonstrated by the presence of Probst bundles associated with colpocephaly occurring in the same mother in her two consecutive pregnancies is reported. Data regarding possible teratogenetic effect due to electromagnetic exposure in utero have also been investigated and raised suspicionus as a potential risk factor. In cases of suspected second trimester ultrasound diagnosis of agenesis of corpus callosum (ACC), the following clinical management should be recommended: fetal karyotype; a second level scan with differentiation between underlying conditions such as hydrocephalus and holoprosencephaly; antenatal MRI to enhance the diagnostic accuracy of possible associated neuronal migration (when possible); and direct demonstration of the presence of the Probst bundles to neurohistology.

Hypertension and microalbuminuria in children with congenital solitary kidneys.

AIM: According to the hyperfiltration hypothesis, a low nephron endowment will lead to hyperfiltration in the remaining glomeruli and is associated with systemic hypertension, proteinuria and glomerulosclerosis. Being born with one functioning kidney instead of two, for instance because of unilateral renal agenesis or multicystic dysplastic kidney, is a cause of congenital renal mass reduction. METHODS: In order to study the effect of congenital renal mass reduction on renal function and blood pressure, a retrospective chart review of 66 patients at the Pediatric Renal Center of the VU University Medical Center was performed. As intrauterine growth restriction is associated with a low nephron endowment, the additional effect of birthweight was also studied. RESULTS: A total of 50% of patients with congenital renal mass reduction is found to be hypertensive, using anti-hypertensive drugs, and/or having microalbuminuria (>20 mug/min). Patients born small for gestational age have significantly smaller kidneys and lower estimated glomerular filtration rate than patients with a normal birthweight. CONCLUSIONS: We conclude that microalbuminuria and/or hypertension is present in 50% of patients with congenital solitary kidneys, which warrants a systematic follow-up of blood pressure, proteinuria and renal function in all patients with congenital solitary functioning kidneys, especially in patients with a low birthweight.

Neonatal Bartter syndrome with unilateral multicystic dysplastic kidney disease.

Neonatal Bartter syndrome is characterized by antenatal presentation with polyhydramnios. In this paper, we report a case of neonatal Bartter syndrome associated with unilateral multicystic dysplastic kidney disease. To our knowledge, this is the first case report of such an association.

Prenatal diagnosis of apparently isolated unilateral multicystic kidney: implications for counselling and management.

Cases where initial prenatal diagnosis was made of isolated unilateral multicystic kidney (UMCK) were reviewed to determine appropriate counselling and management strategies. For the 73 cases, chromosome abnormalities, pregnancy complications and family histories were reviewed. In addition, subsequently diagnosed birth defects, and pediatric medical and surgical outcomes were available for 54 cases. Of those with outcome information available renal/genital-urinary tract abnormalities were diagnosed subsequently in 33% and non-renal abnormalities in 16% of cases. Of the non-renal abnormalities, congenital heart defects were most frequent (7%). One chromosome abnormality, a trisomy 21, was present among 32 cases where karyotypes were known (3%). Amniotic fluid volume abnormalities were present in 11 cases but not predictive of associated anomalies, with the exception of one case where polyhydramnios accompanied multiple malformations consistent with VATER association. A family history of structural renal anomalies was reported in 11 cases (20%). There were 14 cases of partial or complete involution (25%), including two cases of complete prenatal involution of the cystic kidneys. No long-term associated morbidity such as hypertension or malignancy was present in our cohort. Based on our study and corroborating literature, amniocentesis should be offered to women when a seemingly isolated UMCK is detected on routine prenatal ultrasound. Furthermore, a detailed ultrasound with careful assessment of the fetal heart and contralateral kidney is indicated at diagnosis and during the third trimester to assess for further evidence of structural abnormalities, as well as amniotic fluid volume abnormalities. Careful assessment of the newborn is indicated with appropriate speciality referral as required.

Dysplastic and polycystic kidneys: diagnosis, associations and management.

Cystic and bright kidneys can pose a significant diagnostic dilemma when discovered as an incidental finding at the time of a routine fetal ultrasound scan. There are diverse aetiologies with equally variable implications for the prognosis in the affected fetus, and for future pregnancies. Accurate antenatal diagnosis in the absence of any positive family history is often not possible and a team approach to management (to include the fetal medicine specialist, paediatric nephrologist or urologist, geneticists and in some cases, pathologist) is essential. In this review we will attempt to describe the embryology and aetiology of these conditions and suggest an approach to management.

Deficiency of phospholipase C-gamma1 impairs renal development and hematopoiesis.

Phospholipase C-gamma1 (PLC-gamma1) is involved in a variety of intracellular signaling via many growth factor receptors and T-cell receptor. To explore the role of PLC-gamma1 in vivo, we generated the PLC-gamma1-deficient (plc-gamma1(-/-)) mice, which died of growth retardation at embryonic day 8.5-9.5 in utero. Therefore, we examined plc-gamma1(-/-) chimeric mice generated with plc-gamma1(-/-) embryonic stem (ES) cells for further study. Pathologically, plc-gamma1(-/-) chimeras showed multicystic kidney due to severe renal dysplasia and renal tube dilation. Flow cytometric analysis and glucose phosphate isomerase assay revealed very few hematopoietic cells derived from the plc-gamma1(-/-) ES cells in the mutant chimeras. However, differentiation of plc-gamma1(-/-) ES cells into erythrocytes and monocytes/macrophages in vitro was observed to a lesser extent compared with control wild-type ES cells. These data suggest that PLC-gamma1 plays an essential role in the renal development and hematopoiesis in vivo.