Pyeloureteral Junction Obstruction Research Articles

Pilot Study on the Molecular Pathogenesis of Pyeloureteral Junction Obstruction: Underdevelopment or Fibrosis?

Background and Objectives: Congenital ureteral stenosis is one of the leading causes of impaired urinary drainage and subsequent dilatation of the urinary collecting system, known as hydronephrosis or ureterohydronephrosis. The mechanism that leads to obstruction is not clearly known. Multiple studies in rat models have shown increased angiotensin II and TGFβ levels in obstructed ureteral tissue. The aim of the study is to investigate the expression of fibrosis-related genes in obstructive and normal ureteral tissue. Material and Methods: It is a monocentric pilot study in which nineteen patients were selected prospectively. 17 patients underwent Hynes-Anderson pyeloplasty due to the PUJO; two patients underwent ureteroneocystostomy due to ureterovesical junction obstruction (UVJO); and six patients were chosen for the control group: five underwent nephrectomies due to the kidney tumor and one underwent upper pole heminephrectomy due to the duplex kidney with normal pyeloureteric junctions in all. Tissue RNA was chemically extracted after freezing the biopsy samples in liquid nitrogen, with cDNA synthesis performed immediately after nucleic acid isolation. qPCR was performed to evaluate the relative expression of Tgfb1, Mmp1, Timp1, Pai1, Ctgf, and Vegfa. Expression levels of the Gapdh and Gpi genes (geometric average) were used to calculate the relative expression of the investigated genes. Outliers were removed prior to calculating confidence intervals for the experimental groups, and a Wilcoxon rank-sum test was performed to determine the statistical significance of the differences. Results: Significant differences between healthy and stenotic tissue samples in Ctgf gene expression levels were observed, with the samples from afflicted tissue showing lower expression. No statistical difference in expression levels of Tgfb1, Timp1, Vegfa, Mmp1, and Pai1 was found. Conclusions: These findings suggest that tissue fibrosis, similar to other tissues and organs, is not the leading cause of stenosis, at least at the moment of surgery. Decreased CTGF expression is indicative of the developmental origin of obstruction.

Pyelo-ureteral junction obstruction in poorly functioning kidneys: Does conservative management play a role in pediatric patients?

Management of Pyelo-ureteral Junction Obstruction (PUJO) in poorly functioning kidneys in pediatric patients is still controversial, particularly regarding the role of conservative treatment. To evaluate and present the outcomes of internal diversion and follow-up results of a small series of pediatric patients with UPJO in poorly functioning kidneys. Retrospective review of 17 consecutive patients with unilateral PUJO in kidneys with Differential Renal Function (DRF) <20% undergoing temporary internal urinary diversion between 2009 and 2021 at a single tertiary center. DRF was reassessed after 1-3 months of diversion and subsequent management was conservative or surgical (pyeloplasty or nephrectomy) based on surgeon's and family's preferences without randomization. After a trial of internal urinary diversion, 4/17 patients (23%) showed a DRF increase ≥5% (9%-12%), up to a maximum DRF of 28%, 3 underwent pyeloplasty, while 1 was managed conservatively. The remaining 13 patients showed no differential renal function improvement after diversion, and 7 were managed expectantly while 6 surgically (4 pyeloplasty, 2 nephrectomy). Overall, nine patients (53%) were managed surgically and 8 (47%) expectantly After a median (range) follow-up of 3.1 (0.3-7.9) years, no significant difference was observed between groups regarding symptoms (p = 0.205), need for further surgery (p = 1.000), and renal function (p = 1.000). Although fraught with the limitation of a small sample size, this is the first study reporting on the conservative management of this controversial group of patients. In present pediatric series of pyelo-ureteral Junction obstruction in poorly functioning kidneys with differential renal function <20%, function recovery after a trial of internal urinary diversion was quite exceptional, and no difference was observed in outcome between patients managed surgically and conservatively after stent removal.

Atypical segmental multicystic dysplastic kidney with severe reflux in a newborn

Segmental cases of multicystic dysplastic kidney (SMCDK) are rare and hard to diagnose, imaging characteristics are not evident. SMCDK can be presented with duplex collecting system, vesicoureteral reflux (VUR), pyeloureteric junction obstruction and orthotopic ureterocele. Typical cases are localized to the upper pole of a duplex collecting system. Atypical cases are rarely reported. We present an unique atypical SMCDK case, with unconventional disease manifestation to bring attention to the variable presentation of this rare disorder and to draw attention to differential diagnostic challenges of cystic kidney malformations. In our patient newborn screening abdominal ultrasound detected severe hydronephrosis and hydroureter of the lower pole of the right kidney. Dynamic renal scintigraphy and sonocystography confirmed duplication of both collecting systems and severe VUR in the right lower pole. Heminephrectomy was performed. The suspected diagnosis of atypical SMCDK was confirmed by histopathology. The patient recovered uneventfully. This unusual case of atypical SMCDK highlights the importance of considering the possibility of SMCDK in patients with partial kidney malformation or unusual appearance of congenital kidney disease.

When should One Trocar Assisted Pyeloplasty (OTAP) considered as gold standard for the treatment of pyelo-ureteral junction obstruction (PUJO)? our experience: 49 cases

When should One Trocar Assisted Pyeloplasty (OTAP) considered as gold standard for the treatment of pyelo-ureteral junction obstruction (PUJO)? our experience: 49 cases

Robotic pyeloplasty in children - a pilot study.

Pyeloplasty for congenital hydronephrosis (pyeloureteral junction obstruction, PUJO) can be performed as an open, laparoscopic or robotic procedure in children. The aim of this study was to analyze a pilot cohort of pediatric patients operated robotically. A retrospective analysis of the cohort of patients 3 to 18 years of age who underwent primary robotic pyeloplasty between December 2018 (which is when the robotic program was launched at the University Hospital Motol) and June 2021. Patients already operated on for PUJO in the past were excluded. The indication criteria, clinical symptoms, operation time, hospitalization length and complications were evaluated from the medical records. During this period, we operated on 28 children aged 3 to 17 years (median 8); 2 patients were excluded. Of the 26 children analyzed, 6 (23%) were asymptomatic before surgery, 17 (65%) reported pain, 2 (8%) had acute pyelonephritis before the surgery, and 1 (4%) suffered from nephrogenic hypertension. The most common etiology of PUJO was an aberrant vessel in 22 (85%) patients. The time from incision to skin closure was 106 to 201 minutes (median 142 minutes). Patients were hospitalized for 3 to 5 days (median 4) after the surgery and followed up for 1 to 30 months (median 6). Twenty-four of the 26 patients showed regression of the pelvic dilatation according to the postoperative ultrasound scan and no symptoms of PUJO. Seven (27%) had postoperative complications requiring a procedure under general anesthesia (all Clavien-Dindo 3b); of these, 2 were re-operated. Robotic pyeloplasty is an alternative to laparoscopic and open surgery. It is a safe and successful (92%) method. We believe that the higher rate of complications (27%) in our cohort is due to the fact that this is a new technique and more experience is needed.

Transperitoneal Laparoscopic Nephrectomy for Non-Functional Kidneys: A Report of 25 Cases

Background and Aim: Ever since the first-ever laparoscopic nephrectomy performed in 1991 by Clayman, laparoscopy has become the technique of choice for benign renal pathologies and also for cancerous lesions. In this paper, we present and evaluate the results of laparoscopic nephrectomy carried out on patients with non-functional kidneys at the Centre medico-chirugical d’urologie in Douala, Cameroon. Materials and Methods: This was a retrospective study carried out from 2016 to 2020. We included 25 patients with non-functional kidneys who underwent transperitoneal laparoscopic nephrectomy. Results: We included 25 patients (15 males and 10 females) with a mean age of 32.80 ± 9.76 years. Twenty (80%) patients presented with low back pain, four (16%) presented with acute pyelonephritis, and one (4%) presented with both low back pain and hematuria. The right kidney was damaged in 10 (40%) patients and the left kidney in 15 (60%) patients. The kidney failure requiring nephrectomy was due to stones in 16 (64%) patients and upper pyeloureteric junction obstruction in nine (36%) patients. The mean surgery duration was 111.08 ± 31.95 minutes. The median perioperative blood loss was 100 [70 - 120] ml. Percutaneous drainage was required in 13 (52%) patients. Only two (8%) patients developed postoperative complications. The mean follow-up duration was 64 ± 24.48 days. All patients survived the surgical intervention. Conclusion: Laparoscopic nephrectomy is a mini-invasive technique that is suitable for the surgical removal of non-functional kidneys due to either ureteropelvic junction obstruction or massive kidney stones.

Transperitoneal Laparoscopic Nephrectomy for Non-Functional Kidneys: A Report of 25 Cases

Background and Aim: Ever since the first-ever laparoscopic nephrectomy performed in 1991 by Clayman, laparoscopy has become the technique of choice for benign renal pathologies and also for cancerous lesions. In this paper, we present and evaluate the results of laparoscopic nephrectomy carried out on patients with non-functional kidneys at the Centre medico-chirugical d’urologie in Douala, Cameroon. Materials and Methods: This was a retrospective study carried out from 2016 to 2020. We included 25 patients with non-functional kidneys who underwent transperitoneal laparoscopic nephrectomy. Results: We included 25 patients (15 males and 10 females) with a mean age of 32.80 ± 9.76 years. Twenty (80%) patients presented with low back pain, four (16%) presented with acute pyelonephritis, and one (4%) presented with both low back pain and hematuria. The right kidney was damaged in 10 (40%) patients and the left kidney in 15 (60%) patients. The kidney failure requiring nephrectomy was due to stones in 16 (64%) patients and upper pyeloureteric junction obstruction in nine (36%) patients. The mean surgery duration was 111.08 ± 31.95 minutes. The median perioperative blood loss was 100 [70 - 120] ml. Percutaneous drainage was required in 13 (52%) patients. Only two (8%) patients developed postoperative complications. The mean follow-up duration was 64 ± 24.48 days. All patients survived the surgical intervention. Conclusion: Laparoscopic nephrectomy is a mini-invasive technique that is suitable for the surgical removal of non-functional kidneys due to either ureteropelvic junction obstruction or massive kidney stones.

Giant neonatal hydronephrosis of the upper pole of a complete duplicated renal system

Ureteropelvic junction obstruction (UPJO) in the upper pole of a complete duplicated renal system is extremely rare. We report a case that was diagnosed prenatally and we review 10 cases published in the literature. Diagnoses of adrenal hematoma and cystic neuroblastoma were suspected on prenatal ultrasound, based on the severity of dilatation and the difficulty of identifying the exact origin of this anomaly. Neonatal magnetic resonance imagery (MRI) was subsequently able to show a normal adrenal gland. Surgical management is similar to that of a single-system pyeloureteral junction obstruction. Since this situation is very rare, we believe cystoscopy can be useful to confirm diagnosis of UPJO associated with complete duplication, especially in the absence of preoperative MRI. Among the 11 surgical cases previously published, seven patients underwent pyeloplasty and four heminephrectomy.

PYELOPLASTY IN BIFID RENAL PELVIS WITH OBSTRUCTION OF THE LOWER MOIETY

Duplications in the urinary collecting system and pyeloureteral junction obstruction (PUJO) are common, but the simultaneous presence of both anomalies is rarely encountered. In duplicate incomplete systems, PUJO usually affects the lower moiety of the kidney. We present a case of a 2- year old boy with left bifid renal pelvis and hydronephrosis of the lower moiety of the kidney. Keywords: pyeloplasty, bifid renal pelvis, hydronephrosis, Anderson Hynes.

Micropercutaneous endopyelotomy for the treatment of secondary ureteropelvic junction obstruction in children

The management of recurrent pyeloureteral junction obstruction (PUJO) is controversial, as there is no suitable technique for its correction. Percutaneous endopyelotomy shows better results in recurrent PUJO compared to primary PUJO. Micro-percutaneous approaches reduce damage to renal parenchyma and facilitate access to renal pelvis. To present our experience in the use of this minimally invasive technique for the treatment of recurrent PUJO. A retrospective study was performed collecting data of patients with recurrent PUJO treated in our hospital using the percutaneous approach between July 2014 and January 2018. Micropercutaneous access was performed in all patients. In Valdivia position, a 5 or 6mm high-pressure ballon is placed in the renal pelvis under cystoscopic and fluoroscopic guidance. The 4.8 or 8 Fr microperc puncture needle is placed into the pelvicalyceal system. Endopyelotomy is performed with a laser fiber or monopolar hook on a high-pressure balloon. To improve the exposure of the cutting area, the high-pressure balloon is placed at the pyeloureteral junction. Double J stent is left for weeks. The ages of the patients were 4, 8 and 18 months, and 2 and 4 years. All patients had previously undergone pyeloplasty due to pyeloureteral junction obstruction. Operative time was 50±21min. Hospital stay after surgery was 24h and hematuria disappeared within the 24 postoperative hours. The number of patients with recurrent PUJO is small, making it difficult to establish a standard surgical approach for failed pyeloplasty. Redo pyeloplasty is considered the gold standard by some authors but alternative methods, such as endourological techniques, may also have a role in the treatment of failed pyeloplasty. The percutaneous approach has shown very good results in this treatment and the miniaturization of percutaneous surgery has improved with the micropercutaneus access. We consider micropercutaneous approach helped with a high pressure balloon in the pyeloureteral junction is an alternative and minimally invasive technique that has shown good results in our small cases series. However, we must take into account the limitation of the study considering the low number of patients. We need prospective studies to support our results. Micropercutaneous endopyelotomy is a fairly effective technique to treat recurrent UPJO after failed pyeloplasty in children. In our experience, it reduces kidney damage without increasing complications.

Laparoscopic Vascular Hitch for Polar Vessels in Pyeloureteric Junction Obstruction: Medium-Term Follow-up of a Monocentric Experience.

To evaluate medium-term results of the management of patients with pyeloureteric junction obstruction (PUJO) secondary to lower pole vessels managed by a laparoscopic vascular hitch technique. We performed a retrospective monocentric study of all patients who were operated using this technique, transperitoneal laparoscopy (TL) or robotic surgery (RS), from 2011 to 2018. Description of the initial population, pre- and postoperative data was collected and analyzed. During the study period, 25 patients (11 males and 14 females) with a mean age of 11.1 years were managed. Initial symptoms leading to the diagnosis were present in 21 children (lumbar pain 17, high blood pressure 1, and infection 3). Four patients were diagnosed incidentally (three) or following a prenatal screening (one). The diagnostic has been confirmed in all patients by ultrasound scan completed by computed tomography or magnetic resonance imaging scans. Twenty-one patients were operated by TL and four by RS. Mean operating time was 90.2 minutes. Three immediate postoperative complications were noticed including one urinary tract infection, one urinary tract rupture, and one postoperative massive dilatation. After a mean follow-up of 3 1.5 years, 17 patients remain asymptomatic. Mean pelvic diameter was preoperatively 35 mm and postoperatively 10.5 mm (p < 0.005). Of the eight remaining patients, six required reoperation (pyeloplasty) and two remained symptomatic with recurrent flank pain. In our experience, PUJO managed by the vascular hitch technique is associated with a 68% success rate after a 3-year follow-up. These results are different from the current literature which reported success rate of 96% after 52 months. It leads us to question the efficiency of this technique in the long term in our hands both concerning the indications and the surgical procedure itself. Further studies are required to collect data concerning the evolution of our patients during adulthood to compare their evolution to classic pyeloplasty.

MINIMALLY INVASIVE SURGERY FOR CONGENITAL HYDRONEPHROSIS IN CHILDREN

Introduction. Minimal invasive treatment for congenital hydro nephrosis in children remains a controversial topic, both in defining the necessity and timing of operation using laparoscopic techniques in neonates and infants. Materials and methods. This study aims to analyze criteria used for surgery in a series of patients operated in a laparoscopic manner, for congenital hydro nephrosis, at the Emergency Clinical Hospital for Children “Marie Curie” Bucharest, Department of Pediatric Surgery, between 2007-2015. Results. In our series, the most frequent found criteria for surgery were anterior-posterior diameter over 3 cm, followed by 50% reduced parenchymal thickness, decreased renal function under 40% and finally symptomatic criteria – urinary tract infections and flank colicky pain. Both pelvic dilatation and parenchymal thickness correlates with renal function, though reduced parenchymal thickness has a stronger correlation. Infants under 1 year and under 10 kg represented a significant proportion (17.5% and 22.5% respectively). Conclusions. Young age (under 1 year old) and low-weight (under 10 kilos) in children are not reasons to delay classical or laparoscopic surgical treatment for PUJO (pyelo-ureteric junction obstruction). Pyelectasis is not specific to PUJO. It does not always mean obstruction and does not always show a strong correlation with impaired renal function. Best in establishing therapeutic conduct are the magnitude of renal parenchymal restructuring, the degree of renal function impairment and clinical symptomatology. Laparoscopic treatment is an effective surgical approach, that meets all the major advantages of minimal invasive surgery, applicable to infants and small children, regardless of age and weight.

The connection of hydronephrosis and microcirculation deterioration

Abstract In this study, we have analyzed the influence of hydronephrosis upon the microcirculation system, in situations of pyeloureteral junction obstruction. Herein, bulbar conjunctiva has been chosen as the object of this biomicroscopic study because of its simplicity and the method availability in clinic practice. In fulfilling this work, we ascertained the connections between extravascular, intravascular, vascular and general conjunctival indices of the patients before radical and paliatic correction of the pyeloureteral junction obstruction (i.e. by open and laparoscopic pyeloplasty, endopyelotomy, laser resection and balloon dilatation). We concluded that, apart from the proved deterioration of kidney function, systemic deteriorations of microcirculation may be observed in situations of clinically marked hydronephrosis, according to the results of radioisotope renography and excretory urography.

Morphological aspects and distribution of interstitial cells of Cajal in the human upper urinary tract.

The mechanism by which the ureter propels urine towards the bladder has a myogenic origin, through peristaltic contractions. This pyeloureteral autorhythmicity is generated by specialized, electrically active cells, the interstitial cells of Cajal, located in the proximal regions of the upper urinary tract. The aim of this study was to describe the exact location and the distribution of interstitial Cajal cells in the human upper urinary tract and to analyze their normal number and morphology. This is a preliminary study, which will allow the study of these cells in different urinary tract pathologies. Urinary tract fragments were sampled at different levels, from 13 autopsy cases. Cases with clinical evidence of renal disease, and with histological changes in the kidney or in the urinary tract tissue samples, visible in hematoxylin-eosin staining, were excluded. The interstitial Cajal cells were highlighted with anti-CD117 antibody, immunohistochemically. Cajal cells were indirectly highlighted by the presence of a finely granulated cytoplasm indicating immunoreactivity. These cells were spindle-shaped or stellate, with cytoplasmic extensions at one or both poles of the cell and large oval nucleus. We found that interstitial Cajal cells were located at all upper urinary tract levels, with a higher predominance in the calyces and pyelon. Interstitial Cajal cells were observed mostly between the two layers of the muscularis, but also between the muscle bundles. Most often, these cells were parallel to the muscle fibers. Our study describes the method of detection of interstitial Cajal cells in normal human urinary tract. These results can be used to analyze the number, morphology and the location of these cells in different congenital pathologies, such as vesicoureteral reflux, pyeloureteral junction obstruction or primary obstructive megaureter.

Clinical characteristics and outcomes of congenital midureteral stricture detected by fetal ultrasonography

Congenital midureteral stricture (CMS), which develops from obstructive lesion between pyeloureteral junction and ureterovesical junction, is relatively rare and its clinical condition and therapeutic strategy have not yet been established. We analyzed the clinical characteristics and surgical outcomes of CMS. From November 2006 to December 2012, out of 137 patients presented with congenital hydrohephrosis, we identified 4 pediatric patients diagnosed with CMS at our institutions. We retrospectively investigated clinical characteristics and surgical outcomes in these 4 patients. Three boys and one girl were identified in this study. All patients were detected hydronephrosis by fetal ultrasonography. The median age at the diagnosis of CMS was 1 year and 11 months. Three patients had obstructive lesion in left side and 1 patient in right. CMSs were located at the level of L4 in 2 patients, and at the level of L5 and S1 in each 1. Split renal function was decreased less than 45% in 3 of 4 patients. Ipsilateral pyeloureteral junction obstruction and ipsilateral hypoplastic kidney were identified in 2 and 1 patient, respectively. One patient developed urosepsis and underwent nephrostomy. Partial ureterectomy and ureteroureterostomy, pyeloplasty were performed in 3 and 1 patient, respectively. Extrinsic obstruction was detected in just 1 patient intraoperatively. In all patients, there were no protruded lesion and atrophied, fibrotic and ischemic muscles were not detected in pathological finding. Neither urinary tract infection nor recurrence of obstructive lesion was detected in all patients at the mean follow-up period of 3 years and 1 month. We analyzed the clinical characteristics of 4 pediatric patients with CMS. In order to prevent critical infection and maintain renal function, it could be considered that surgical intervention is undertaken just after making the diagnosis of CMS.

Laparoscopic Treatment of Urinary Stones After Failure of Previous Mini-Invasive Approaches

Introduction: Urolithiasis in the general population has been estimated at about 5%–12%, with an annual incidence of just over 1% and recurrence rates close to 50% involving patients of all races, ages, and gender.1 There are several methods for the management of patients with urinary stone disease.1 Within the therapeutic options, we have minimally invasive procedures, such as percutaneous nephrolithotomy (PNL), shockwave lithotripsy (SWL), and endoscopic ureterolithotripsy (EUL). Laparoscopic pyelolithotomy, laparoscopic ureterolithotomy, and laparoscopic cystolithotomy are now considered second-line therapeutic procedures, whereas open surgery still represents an effective more invasive treatment.2 We present our case series on laparoscopic management of renal, ureteral, and bladder stones previously unsuccessfully treated with mini-invasive procedures. Materials and Methods: From September 2010 to April 2012, 18 patients, previously treated with minimally invasive techniques (PNL, SWL, and EUL), underwent laparoscopic surgery for urinary tract stones. Epidemiological, clinical, and surgical variables were reviewed. Clinical variables, such as the presence of unilateral or bilateral stones and their position (renal pelvis, proximal, middle, or distal ureter and bladder), were taken into account. The mean operative time, use of indwelling ureteral stent, postoperative hospitalization, stone clearance rate, and perioperative complications were analyzed. No patient had associated morbidities that required any other additional procedure (pyeloureteral junction obstruction, urinary diversions, etc.). Results and Conclusions: Eighteen laparoscopic procedures were performed: nine ureterolithotomies, six cystolithotomies, and three pyelolithotomies. The mean age of the patients was 48 years (27–66 years), all were Caucasian subjects: 14 males and 4 females. No patient had acute renal failure. The mean serum creatinine value was 1.01 mg/dL (range: 0.8–2.5 mg/dL). Two patients presented a bilateral location of the stones. Stone position was as follows: nine ureteral (three proximal, two middle, and four distal), six in the bladder, and three in the renal pelvis. The mean operative time was ureteral stone, 82 ± 23 minutes; bladder stone, 47 ± 10 minutes; and kidney stone, 99 ± 26 minutes. Transfusion was not required in any patient, and the open conversion did not happen. The mean hospital stay was 3 days (2–4 days). The overall stone clearance rate was 88.9% (16/18), and two patients had residual kidney stones that were managed with extracorporeal SWL. At a mean follow-up of 6 months, no serious complications (bleeding, sepsis, bowel injury, ureteral strictures, or urinary leakage) occurred. Laparoscopic surgery is an effective and safe technique for the management of urinary tract stone disease, with a high stone clearance rate. Considering our case series and the literature,2,3 it might be considered an alternative second-line procedure in selected cases where other less invasive procedures (SWL, PNL, etc.) had failed. The authors declare that no competing financial interests exist. Runtime of video: 6 mins 47 secs

Altered expression of c-kit-positive cells in the ureterovesical junction after surgically created vesicoureteral reflux

Peristaltic contractions propel urine unidirectionally from the renal pelvis trough the ureter and into the bladder. A morphologically and functionally competent ureterovesical junction prevents vesicoureteral reflux (VUR). According to current knowledge, pyeloureteral peristalsis is driven by atypical muscle cells within the upper urinary tract. Another likely relevant cell population, which is c-kit-positive, has been shown to be present within the whole urinary tract. Morphological changes of c-kit-positive cells have been described in VUR and pyeloureteral junction (PUJ) obstruction. Nevertheless, the functional importance of c-kit-positive interstitial cells has not yet been elucidated fully. Therefore, we investigated the influence of experimentally created VUR on the expression of c-kit-positive cells. We created left-sided unilateral VUR in eight Vietnamese pigs using an open surgical technique. The VUR was shown to be grade II-III by voiding cystourethrogram (VCUG), 1 and 6 months after the procedure. The animals were killed after 6 months. The vesicoureteral junction and the distal ureters were excised and fixed in 4% PFA. Paraffin sections were stained using c-kit immunohistochemistry. A quantitative evaluation was performed by two independent investigators. The unaffected, contralateral, nonrefluxing ureters served as controls. We identified two types of c-kit-immunoreactive cells within the ureterovesical junction and distal ureter. The first group was comprised of round-shaped cells with substantial intracellular granulas, which resembled mast cells. Mast cells were found in the subepithelial region as well as between the muscle bundles. The number of mast cells was slightly increased in the VUR group. The second group consisted of spindle-shaped, bipolar ICC-like cells, which were seen mainly in the submucosal and muscular layers. The number of spindle-shaped c-kit-immunoreactive cells was markedly decreased in the refluxing ureter compared to the controls. Surgically created VUR leads to altered expression of c-kit-positive cells. The altered distribution of c-kit-positive ICC-like cells might further contribute to the impairment of coordinated pyeloureteral peristalsis.

Resultados a medio plazo del tratamiento endourológico retrógrado con balón de la estenosis pieloureteral en niños menores de 1 año

AimIn the last years it has spread minimally invasive therapeutic for the treatment of pyeloureteral junction obstruction in children. Some of them have got poor outcomes in 4-year-old minor children. We show our experience in the retrograde dilatation with balloon of high pressure in infants. MethodsIt´s a retrospective study of 16 infants treated in our hospital. The average follow-up after the intervention is 27.4±10.0 months. The diagnostic protocol included abdominal ultrasound, cystogram and diuretic renography. The treatment was realized by endourology retrograde balloon dilatation under fluoroscopy. The balloons were in all the cases semicompliant, with a profile of 5 mm, 6 mm ó 7 mm. After the expansion there was placed stents type double J with profile and length depending on the weight of the patient. To obtain the results, we do ultrasound scans and diuretic renography at least 1 year after the intervention. ResultsThe mean duration of the intervention was 36.4±15.5 minutes. During the intervention, in 2 patients the placement of the stent was not possible. The time of revenue was 48 hours in all the patients except in 1 of them. The analgesic needs were exclusively non steroid antiinflammatorys. The double J stent was withdrawn with cystoscopy. In 3 patients there were postoperatory complications: a migration of the stent, a urinary infection and an urinoma. In 1 patient with worsening of hydronephrosis was needed of pyeloplasty. In the controls the disappearance of the hydronephrosis was observed in all the cases, eliminating likewise the expansion of the renal calyces. The diuretic renography improved in all babies, being the boss of the curve normal in 14 cases and semi obstructively in 2. The mean time of elimination was 9.8±2.8 minutes. ConclusionsWe think that the balloon dilatation of pyeloureteral junction obstruction is a minimally aggressive technique that is possible to realize in infants with good results and scanty complications.

Diagnostic accuracy of color Doppler sonographic study of the ureteric jets in evaluation of hydronephrosis

Objective Hydronephrosis (HN) and obstruction are closely associated, but upper urinary tract dilatation can occur without significant obstruction. Despite some pitfalls, conventional ultrasonography and diuretic renography (DR) are the main means of evaluation of HN in children. Recent reports have demonstrated color Doppler ultrasonography (CDUS) to reliably identify ureteric jets in the bladder. The aim of this study was to evaluate this method as a diagnostic tool to distinguish obstructive from non-obstructive dilatations of the upper tract. Methods We evaluated 51 patients (37 boys and 14 girls), aged 3 months to 14 years (median 4 years), who presented with unilateral grade III and IV hydronephrosis with suspicion of pyeloureteral junction obstruction. All patients underwent DR and evaluation of ureteric jets by transverse CDSG of the bladder within a maximum of 2 weeks. Obstruction was considered in the DR when the hydronephrotic unit showed a differential renal function of less than 40%, or when symptomatic intermittent renal colic was present in older children. The number of ureteric jets was counted over a 5-min period and the frequency calculated for each ureteral orifice. Relative jet frequency (RJF) was defined as frequency of the hydronephrotic side divided by total ureteric jet frequency. Receiver-operating characteristic (ROC) plots were constructed to determine the best cut-off for RJF, in order to identify renal units with obstructive hydronephrosis. Results Twenty-three (45.1%) hydronephrotic units were considered obstructed. The mean RJF differed between obstructive (0.09 ± 0.15) and non-obstructive hydronephrosis (0.42 ± 0.11) ( p < 0.001). ROC analysis revealed that RJF <0.25 was the best threshold, and correctly discriminated obstruction in 91.2% of the children with a sensitivity of 87% (95% CI 78.6–98.2%) and specificity of 96.4% (95% CI 87.8–99%). The positive likelihood ratio was 24.3 and the area under the ROC curve was 0.92 (95% CI 0.86–0.98). Conclusions RJF <25% was found to be a good indicator of obstruction in children with unilateral hydronephrosis. CDUS evaluation of ureteric jets is an easy and non-invasive method that can be used as an initial diagnostic tool, and in follow-up cases, to differentiate obstructed from non-obstructed hydronephrosis in the pediatric population.

Urinary Sodium Dodecyl Sulfate Electrophoresis With Silver Staining: A Noninvasive Diagnostic Tool for Obstructive Uropathy in Children

Obstructive uropathy such as ureteropelvic junction obstruction in the newborn is a major diagnostic and therapeutic dilemma. We investigated whether urinary sodium dodecyl sulfate electrophoresis with polyacrylamide gel electrophoresis with silver staining could be used to discriminate between children requiring and those not requiring pyeloplasty. In a pilot study we analyzed the urine of 18 children (mean age 2.7 years) with grade III or IV hydronephrosis according to the Society for Fetal Urology classification. A total of 44 healthy children were studied as controls. Children with hydronephrosis were followed using ultrasound, (99m)technetium mercaptoacetyltriglycine diuretic renography and voiding cystourethrography. Urine was obtained by spontaneous voiding and studied by sodium dodecyl sulfate polyacrylamide gel electrophoresis with silver staining using Melzer's modification. After the study period test results were compared to outcomes, ie whether patients required surgery, and to normalization of previously abnormal protein excretion patterns. All but 1 of the healthy controls had a normal electrophoresis assessment. Of 9 patients followed for hydronephrosis 7 had an abnormal electrophoresis result preoperatively. One child had to be operated on twice because of relapse of ureteropelvic junction obstruction. Six children returned to a normal electrophoresis result postoperatively, including the child who was operated on twice. All children with an initially normal electrophoresis assessment displayed persistent normal values, except 1. Children shifting from a normal to an abnormal electrophoresis result underwent surgery after exclusion of urinary tract infection. Sodium dodecyl sulfate polyacrylamide gel electrophoresis with silver staining seems to be a good predictive test for clinically relevant ureteropelvic junction obstruction. Further studies are being performed to see whether the test can stand against the gold standard, (99m)technetium mercaptoacetyltriglycine diuretic renography.