Congenital Ureteropelvic Junction Research Articles

Changes in Cajal cell density in ureteropelvic junction obstruction in children

Congenital ureteropelvic junction obstruction is one the most common causes of neonatal hydronephrosis. The etiology of the ureteropelvic junction (UPJ) obstruction has not been clearly established. The presence of a hypoplastic, adynamic ureteral segment is thought to be the major cause of an UPJ obstruction. We evaluated the distribution of Cajal cells using immunohistologic methods coupled with light microscopy of the UPJ tissues in obstructed and normal UPJs. The study group consisted of 19 patients who underwent pyeloplasty for UPJ obstruction. Twelve patients who had been operated on for oncological indications constituted the control group. The sections were stained immunohistochemically using CD117 (c-kit) antibody; the numbers of CD117 (+) interstitial cells of Cajal were counted in 10 consecutive high-power fields under the light microscope and the cell density was determined for each case. The mean age of the cases who underwent dismembered pyeloplasty and the control group were 116 ± 116 months (14 male, 5 female; 6-420 months) and 279 ± 312 months (9 male, 3 female; 24-948 months) (p = 0.1), respectively. The mean interstitial Cajal cell number in the UPJ obstruction and the control groups were 2.37 ± 2.19 and 24.5 ± 9.73, respectively (p < 0.0001). Thirteen (68.4%) patients had very few, five (26.3%) patients had few, and one (5.3%) patient had many Cajal cells in the UPJ obstruction group. In the control group, all patients had more than seven cells per high-power field. We found that in cases of UPJ, obstruction the numbers of interstitial Cajal cells were decreased, being either absent or significantly reduced. Although data about the motility are currently not sufficient, the decrease in the number of Cajal cells in patients with UPJ highlights that they might be responsible for the initiation, coordination, and conduction of peristaltic activity along the pelvicalyceal system. Improvement and enhancement of contraction waves arising from the upper urinary system depend on interstitial cells of Cajal, which are the pacemaker cells in smooth muscles. We think that a decreased number of interstitial cells of Cajal have a close relationship with changing ureteral motility when we compare our UPJ obstruction cases with the limited data in the literature. Further investigations on these cells will probably give detailed information about the neurophysiology of the urinary system and the diseases that cause congenital hydronephrosis.

Cell Type Specific Changes in BMP-7 Expression Contribute to the Progression of Kidney Disease in Patients with Obstructive Uropathy

Congenital urinary tract obstruction is a leading cause of renal maldevelopment and pediatric kidney disease. Nonetheless, few groups have examined its molecular pathogenesis in humans. We evaluated the role of BMP-7, a protein required for renal injury repair and nephrogenesis, in disease progression in patients with obstructive uropathy. Whole kidney and cell specific BMP-7 expression was examined in a murine model of unilateral ureteral obstruction and in patients with congenital ureteropelvic junction obstruction. Findings were correlated with molecular markers of renal injury and clinical parameters. Unilateral ureteral obstruction led to a dramatic decrease in BMP-7 expression in the proximal and distal tubules before the onset of significant loss of renal architecture and fibrosis, suggesting that this is a critical molecular event that drives early stage disease progression. Loss of BMP-7 expression then extended to the collecting ducts and glomeruli in end stage kidney disease. When translating these findings to patients with ureteropelvic junction obstruction, global loss of BMP-7 expression correlated with a decreased number of nephrons, loss of renal architecture, severe renal fibrosis and loss of kidney function. Given that BMP-7 has a critical role in renal injury repair and nephrogenesis, these findings show that cell specific changes in BMP-7 expression contribute to the onset of irreversible renal injury and impaired kidney development secondary to congenital urinary tract obstruction. Accordingly therapies that target these cell populations to restore BMP-7 activity may limit disease progression in patients with obstructive uropathy.

Robotic Pyeloplasty and Synchronous Removal of Many Kidney Stones: A Piece of Cake with Robotic Surgery

Ureteropelvic junction obstruction is a common clinical entity in urological practice. The obstruction can result from intrinsic or extrinsic factors. The clinical course is variable due to degree of obstruction. Diagnose is usually made by contrast-enhanced excretory imaging modalities and nuclear scan. Open surgical, laparoscopic and robotic assisted laparoscopic approaches are the available surgical treatment options. In this case report, we present a congenital ureteropelvic junction obstruction treated with robotic assisted transperitoneal pyeloplasty with many intracalyceal stones surprisingly noticed during surgery and successfully treated in the same session.

Giant hydronephrosis mimicking as gross ascites in a 6-year-old boy

Giant hydronephrotic kidney is a rare form of obstructive uropathy in children and adolescents. The congenital ureteropelvic junction obstruction is the most frequent cause. The CT scan is very important for the diagnosis. We report a 6-year-old boy with progressively increasing abdominal distension since birth. There were no associated urinary or gastrointestinal symptoms. He had bilateral hydronephosis with giant hydronephrosis over right side. The cystic mass occupied the right retroperitoneal space and crossed the midline.

Transitional cell carcinoma: A rare development in congenital ureteropelvic junction obstruction kidney

Transitional cell carcinoma: A rare development in congenital ureteropelvic junction obstruction kidney

Changes in Collagen Type 3, Elastin, Fibrosis and Cajal Cell in Congenital Ureteropelvic Junction Obstruction

Changes in Collagen Type 3, Elastin, Fibrosis and Cajal Cell in Congenital Ureteropelvic Junction Obstruction

VE26: Robotic pyeloplasty and synchronous removal of many kidney stones: A piece of cake with robotic surgery

Ureteropelvic junction obstruction is a common clinical entity in urological practice. The obstruction can result from intrinsic or extrinsic factors. The clinical course is variable due to degree of obstruction. Diagnose is usually made by contrast-enhanced excretory imaging modalities and nuclear scan. Open surgical, laparoscopic and robotic assisted laparoscopic approaches are the available surgical treatment options. In this case report, we present a congenital ureteropelvic junction obstruction treated with robotic assisted transperitoneal pyeloplasty with many intracalyceal stones surprisingly noticed during surgery and successfully treated in the same session.

Pediatric Robotic Pyeloplasty in Patients Weighing Less Than 10kg Initial Experience

To report the feasibility and safety of a robotic-assisted laparoscopic pyeloplasty (RALP) in patients weighing <10 kg. Three patients weighing between 5 and 8 kg who were affected by severe congenital ureteropelvic junction obstruction, including a child with solitary kidney, were subjected to RALP. Three trocars were placed; sutures and pyeloplasty remodeling were performed with interrupted stitches. A double J stent was inserted through a 2-mm transparietal angiocatheter to protect the pyelic suture. The procedures were all completed within 90 minutes, the "docking" time requiring 20 minutes. The patients were discharged on postoperative day 2, without any complications. Comprehensive assessment of pyelic suture in a very narrow field with 2 operative instruments is feasible and safe. Robotic pyeloplasty provides all the advantages of mini-invasive surgery with the added advantage of higher magnification and excellent surgical navigation in very small spaces and on fragile infant tissues.

Stentless laparoscopic pyeloplasty: A single center experience.

Aim:To assess the effectiveness of laparoscopic stentless pyeloplasty for congenital ureteropelvic junction obstruction.Materials and Methods:This was a prospective comparative study conducted over a period of 5 years. The study included 35 cases of primary ureteropelvic junction obstruction (UPJO) with mean age of 29.5 years, divided in two groups- Group A (stent-less, 18 patients) and Group B (stented, 17 patients). Follow up ranged from one to 4years (mean 2 years). Transperitoneal laparoscopic Anderson- Hyene's pyeloplasty was standard for both the groups. Perioperative and postoperative complications were prospectively collected and analyzed by Statistical Package for Social Sciences (SPSS) 17 version using Pearson chi square test.Results:Both the groups were comparable with respect to preoperative differential renal function (DRF) and time required for maximum activity in minutes (tmax.min). Average post operative DRF was significantly higher than preoperative DRF in both the groups. Average tmax was significantly lower after pyeloplasty than pre operative tmax. Mean operative time, mean duration of urethral catheter, and mean duration of drain removal were comparable in both the groups. However bothersome irritative lower urinary tract symptoms (LUTS) and hematuria were significantly more in group B patients (P < 0.0001 and <0.013 respectively).Conclusion:In experienced hands, laparoscopic stentless pyeloplasty is as effective method for treating UPJO as its stented counterpart. It is cost effective, avoids stent-related morbidity, and could be performed without compromising the success rate. However, more randomized studies are needed to evaluate the safety of stentless pyeloplasty.

Changes in structure, interstitial Cajal-like cells and apoptosis of smooth muscle cells in congenital ureteropelvic junction obstruction

The goal of this study is to evaluate some structural changes in muscular, collagenous and neural components as well as expression of Cajal-like cells and apoptosisof smooth muscle cellsincongenital ureteropelvic junction obstruction (UPJO). Tissue specimens were obtained from 25 patients with UPJO and compared with normal ureteropelvic junction regions of 19 autopsies. In paraffin embedded sections the amount of Cajal-like cells, density of nerve fibers and smooth muscle cell apoptosis (using immunohistochemical staining) were determined. Collagen deposition and muscular components were stained by Trichrome-Masson staining and evaluated by image analysis techniques. Arrangement of muscular bundles was also evaluated qualitatively. The number of Cajal-like cells was significantly lower in patients than in controls. The apoptotic score and mean number of nerve fibers were not statistically different for the two groups. Arrangement of muscular fibers was more irregular in patients than in controls ( p p p = 0.09). We found significant pathologic changes in congenital ureteropelvic junction obstruction such as decrease in Cajal-like cells, increase in collagen deposition and irregular arrangement of muscle fibers.

Hydronéphrose géante chez l’enfant : à propos d’une observation

Giant hydronephrosis in children is uncommon. Congenital ureteropelvic junction obstruction is the most frequent cause. The CT scan is very important for the diagnosis. We report on a case of hydronephrosis in a 12-year-old child who presented with enormous abdominal distension. The treatment included nephrectomy after waiting nephrostomy. The current literature is also reviewed.

The distribution of interstitial cells of Cajal in congenital ureteropelvic junction obstruction

PurposeThe authors analysed the distribution of c-kit-positive interstitial cells of Cajal (ICCs) in obstructed ureteropelvic junction (UPJ) and its age-related changes.MethodsTwenty specimens were obtained from children with intrinsic ureteropelvic junction obstruction (UPJO), at the average age of 8.1 years (8 months–16.8 years), fixed in formalin and embedded in paraffin. Five control samples were taken from children at the average age of 2.3 years (2.4 months–7.4 years). All specimens were analysed by the immunohistochemistry test with light microscopy with respect to c-kit expression. The distribution of c-kit-positive ICCs in the two groups was compared and the correlation between the distribution of c-kit-positive ICCs and the patients’ age in UPJO cases was analysed. The results were examined by Yates’ χ2 test, Mann–Whitney U test, and t test for Pearson’s correlation coefficient. A P value < 0.05 was considered as statistically significant.ResultsNo statistically significant differences were found in the distribution of c-kit-positive ICCs between UPJO and the control group. No correlation was established between the age of patients with UPJO and the distribution of c-kit-positive ICCs.ConclusionNo distributional difference found in obstructed and unobstructed UPJ seems to indicate that UPJO is not associated with anomalous distribution of c-kit-positive ICCs. Age-related changes in the expression of c-kit-positive ICCs are equally distributed in obstructed UPJ.

Cajal-like interstitial cells as a novel target in detrusor overactivity treatment: true or myth?

IntroductionThe Cajal–like intestitial cells (ICCs) act as a pacemaker and are responsible for generating smooth muscle activity in the gastrointestinal tract (GI). Interstitial cells that resemble ICCs in the GI have been identified in the urinary bladder.Materials and methodsThis review is based on a systemic literature research. The medline/pubmed, scopus, embase, and Web of Science databases were browsed in order to identify original and review articles, as well as editorials relating to cajal–like cells, urinary bladder, detrusor overactivity, overactive bladder, glivec, etc. The controlled vocabulary of the Medical Subject Headings (MeSH) database was used to ensure the sensitivity of the searches. 40 papers met the criteria and were used for this review.ResultsCajal cells lie in close proximity to the muscle cells, autonomic nerve endings, and urothelial cells. There is increasing evidence that ICCs play role in urinary tract dysfunction development (e.g. detrusor overactivity, primary obstructive megaureter, congenital ureteropelvic junction obstruction, etc.). ICCs may be responsible for generating electrical potentials and induction of detrusor muscle contractions. Novel pathomechanisms of detrusor overactivity development have been postulated, as follows: 1) the disturbance of spontaneous contractility caused by altered signal transduction of ICCs between nerves and detrusor muscle cells, and 2). the alteration in signal transduction between urothelium and afferent nerve endings via suburothelial ICCs. The c–kit receptor is not only a detection marker of these cells, but may also play a crucial role in the control of bladder function.ConclusionsCajal cells in urinary bladder suggest that the c–kit receptor may provide a novel target for treating detrusor overactivity. The review presents the current knowledge of ICCs, its role in urinary bladder function, and potential novel therapeutic strategy.

Pacemakers in the upper urinary tract

Pacemakers in upper urinary tract (UUT) are still under study. We reviewed the role of some cells that seem to be involved in the propulsion of urinary bolus from UUT to the bladder. We focuses on evaluating studies on the mechanisms by which the UUT propels urine to the bladder via pacemaker cells. Electric active pacemaker cells generate pyeloureteric autorhythmicity driving adjacent smooth muscle cells (SMCs); it emphasizes the role of the interstitial cells of Cajal-like cells (ICC-LCs) localized in the UUT. Interstitial cells of Cajal (ICCs) are now thought to cooperate in conducting and amplifying pacemaker activity in the UUT. These cells produce electrical slow-wave potentials and determine the propagation of peristaltic activity. Identification of ICC-LCs is facilitated by use of c-kit antibodies. Contraction waves arising from the UUT and the propagation of these waves may require the direct involvement of ICC-LCs, as c-kit immunoreactivity appears developmentally at the same time as coordinated unidirectional peristaltic contraction. ICC-LCs observed in the UUT have morphological features similar to those of c-kitpositive ICCs in the gastrointestinal tract. In addition to gastrointestinal motility, ICCs may also play a significant role in the propagation, coordination, and modulation of ureteropelvic peristalsis. Alterations in ICC-LCs are closely associated with a variety of motility disorders and many congenital urological diseases of the UUT such as primary obstructive megaureter, congenital ureteropelvic junction obstruction, and vesicoureteral reflux. These observations open the way for further investigations of this cell type.

The transition from open to laparoscopic pediatric pyeloplasty: A single-surgeon experience

IntroductionWe present outcomes from a single-surgeon experience in a practice that transitioned away from an open towards a strictly laparoscopic approach to the surgical correction of congenital ureteropelvic junction (UPJ) obstruction. Material and methodsA retrospective chart review was performed on all patients undergoing a dismembered pyeloplasty for UPJ obstruction by one surgeon in 2004–2010. A total of 75 (49 open group (OG), 26 laparoscopic group (LG)) procedures (4 bilateral, 4 re-operative (1 outside institution)) in 67 (66% male, and 73% white) patients were available for review. Median age was 10 months (<1–132) for the OG and 72 months (2–204) for the LG (p < 0.001). The UPJ obstruction was left in 55%, right 34% and bilateral in 11%. A crossing vessel was present in 32% of procedures. None of these values were statistically different in comparing the two cohorts. Patients either had SFU grade IV hydronephrosis, worsening SFU Grade III with tension, or were symptomatic. A total of 36 patients presented symptomatically. Co-morbidities were present in 9%. All patients in the LG were stented post-op compared to 35% in the OG (p < 0.001). Outcome variables assessed included learning curve, post-op result (worse, improved, same), complications, need for intervention and length of stay. The surgeon had some exposure in residency to hand-assisted laparoscopy. In pediatric urology fellowship, all complex procedures were performed open. ResultsMean operative time was significantly longer in the LG: 387 min vs 281 min in the OG (p < 0.001). The learning curve trend line for both cohorts demonstrated slight improvement over time, but confidence intervals were wide in both and this trend was not significant. Following surgical intervention, the length of stay was comparable between the two groups with 96% discharged post-op day 1 in LG and 87% in OG (p = 0.2). With a minimal follow-up of 6 months, most patients demonstrated improvement in hydronephrosis (LG 96% vs OG 96%). Re-operation was successfully performed in 3 patients (2 OG, 1 LG) for persistent obstruction. Complications were present in both groups: 14% OG and 8% LG (p = NS). ConclusionsIn summary, it is feasible to successfully transition from an open surgical practice towards a strictly laparoscopic approach to the surgical correction of UPJ obstruction. Even in the absence of laparoscopic training in fellowship, the learning curve should be relatively flat with the laparoscopic repair but will always take longer than the open procedure.

503 The ultrasonographic evolution of the hydronephrosis and renal parenchyma thickness in patients with congenital ureteropelvic junction (UPJ) obstruction who underwent pyeloplasty

INTRODUCTION AND OBJECTIVES: Introduction: Pyeloplasty is an established treatment for pelviureteric junction (UPJ) obstruction. After pyeloplasty diuretic renograms are often obtained to document surgical success by demonstrating better urinary drainage. However, while diuretic renograms may be the most accurate way to evaluate surgical outcome in the early postoperative period, renal ultrasound is more commonly used for long-term followup because it is less invasive and more cost-effective. OBJECTIVE: The aim of this study was to determine the ultrasonographic evolution of the pelvic and caliceal dilatations and of the renal parenchyma thickness in patients with congenital hydronephrosis who underwent pyeloplasty. METHODS: Materials and Methods: From January 2006 to January 2010, 265 patients with prenatally diagnosed hydronephrosis underwent a protocol of antibiotic prophylaxis, ultrasound, diuretic renography(DTPA) and voiding cystourethrography. Of the 265 patients, 85 (32%) who showed a trend of progressive hydronephrosis underwent pyeloplasty and were included. All the patients were evaluated with DTPA scans on the sixth month after surgery. The ultrasound performed before the surgery as well as all performed in the first 3,6,12,24 and 36 months after the pyeloplasty were reviewed and compared. The trends in the changes in these studies were studied. Statistical analyses were performed with SPSS (Statistical Package for the Social Sciences) version 18.0. RESULTS: All patients significantly improved the renal washout time (T1⁄2) in DTPA scans at six months postoperatively. The rate of caliceal dilatation decrease in the first 3, 6 and 12 months after surgery were 60%, 91,7%, and 100%, respectively. In a follow-up period of at least 1 year, 43 (50,6%) renal units had complete resolution of the pelvic dilation and 72 (84.7%) of the caliceal dilatation. The renal parenchyma was normal or had increased in 76 (89,4 %) of cases. CONCLUSIONS: The decrease in pelvic and caliceal dilatations occurred in the majority of the patients, but its complete resolution is relatively slow. Serial ultrasound is noninvasive and could replace serial invasive renal scans decreasing costs, instrumentation, and radiation exposure.

Urinary Proteome Analysis at 5-Year Followup of Patients With Nonoperated Ureteropelvic Junction Obstruction Suggests Ongoing Kidney Remodeling

Severe ureteropelvic junction obstruction is treated surgically. However, for milder cases most clinical teams adopt a watchful waiting approach and only operate in the presence of significant decline of renal function combined with severe hydronephrosis. Little is known about the long-term consequences of ureteropelvic junction obstruction. Using capillary electrophoresis coupled with mass spectrometry, we analyzed the urinary proteome of 42 patients with ureteropelvic junction obstruction 5 years postoperatively or 5 years following spontaneous resolution. At 5-year followup urinary proteomes were similar between patients with early surgical correction of ureteropelvic junction obstruction and age matched controls. In contrast, urinary proteomes differed significantly between conservatively followed patients and controls. Analyses of the proteomic differences suggested ongoing renal or ureteral remodeling in the conservatively followed patients that was not visible clinically. Long-term followup studies are warranted in patients with ureteropelvic junction obstruction, especially those followed conservatively, to determine whether the observed changes in the urinary proteomes become clinically relevant at a later stage.

Mutation screening of BMP4 and Id2 genes in Chinese patients with congenital ureteropelvic junction obstruction

Ureteropelvic junction obstruction (UPJO) is the most common congenital anomaly of the urinary tract. Evidence has shown that BMP4 and Id2 play crucial roles in nephrogenesis, alterations of which may cause ureteral developmental anomalies. Here, we directly sequenced the coding sequences in BMP4 and Id2 genes of 108 unrelated Chinese patients with ureteropelvic junction stenosis. One missense mutation c.485G> A (p.R162Q) in BMP4 and two synonymous mutations (c.1167T> C in BMP4 and c.108A> G in Id2) were detected in three cases. None of these variations were present in the 150 normal controls. Comparative amino acid sequence alignments of BMP4 in humans and other vertebrate orthologs show that p.R162 located to a highly conserved amino acid residue. Moreover, computational analysis predicted that R162Q probably infect the function of BMP4 protein. The mutation c.485G> A in BMP4 might be one of the causes of human UPJO. Further functional studies are required to validate the association between this variation and UPJO. Otherwise, Id2 mutations do not seem to be involved in this disease.

Bloody Urine after Minor Trauma in a Child: Isolated Renal Injury versus Congenital Anomaly?

Bloody Urine after Minor Trauma in a Child: Isolated Renal Injury versus Congenital Anomaly?

Changes in interstitial cell of Cajal-like cells density in congenital ureteropelvic junction obstruction

PurposeThe authors examined the number of interstitial cells of Cajal-like cells (ICC-LCs) in obstructed ureteropelvic junction (UPJ) in comparison with normal UPJ specimens and age-related changes.Materials and methodsA total of 20 human formalin fixed, paraffin-embedded specimens of intrinsic UPJO from children at the mean age of 8.1 years (age range: 8 months–16.8 years) and 5 control samples from children at the mean age of 2.3 years (range 2.4 months–7.4 years) were investigated immunohistochemically for the expression of c-kit proto-oncogene by light microscopy with computerized image analysis. The results were examined by Fisher’s exact test, Yates’ chi-square test, and t test for Pearson’s correlation coefficient. A P value less than 0.05 was considered statistically significant.ResultsThe number of ICC-LCs-dense fields was significantly higher in UPJO specimens in comparison with the normal group (P = 0.0004). The number of ICC-LCs-sparse fields was significantly lowered in UPJO specimens in comparison with the normal group (P = 0.0122). There was no significant difference in the number of ICC-LCs-medium fields in obstructed and normal UPJ specimens. The number of ICC-LCs was decreasing significantly with increasing age of the patients with UPJO (P = 0.0038).ConclusionsThe higher density of c-kit-positive ICC-LCs in UPJ may manifest the compensation of altered peristalsis in UPJO. The number of ICC-LCs-dense fields decreasing with age may show the failure of compensation and regression of the compensatory changes.