Kidney collecting system anatomy applied to endourology - a narrative review.

OBJECTIVE: To evaluate the surgical anatomy of the kidney collecting system through a narrative review of the literature, highlighting its importance during diagnosis and its approach during surgical procedures for the treatment of renal stones. MATERIAL AND METHODS: We carried out a review about the anatomy of the kidney collecting system. We analyzed papers published in the past 40 years in the databases Pubmed, Embase and Scielo, and we included only papers in English and excluded case reports, editorials and opinions of specialists. RESULTS: Renal collecting system could be divided in four groups: A1 - kidney midzone (KM), drained by minor calyx that are dependent on the superior or the inferior caliceal groups; A2 - KM drained by crossed calyx, one draining into the superior caliceal group and another draining into the inferior caliceal group; B1 - KM drained by a major caliceal group independent of both the superior and inferior groups; and B2 - KM drained by minor calyx entering directly into the renal pelvis. Some details and anatomic variations of the collecting system are related to clinical and radiological aspects, particularly perpendicular calyces, interpyelocalyx space, position of calyces in relation to renal border, classification of the renal collecting system, infundibular diameter and the angle between the lower infundibulum and renal pelvis. CONCLUSION: The knowledge of intra-renal collecting system divisions and variations as the angle between the renal pelvis and lower infundibula, position of the calices in relationship with renal edge and the diameter and position of the calyces are important for the planning of minimally invasive renal surgeries.

Single Port Robotic Pyeloplasty: early single-center experience.

PURPOSE: Ureteropelvic junction obstruction (UPJO) is a prevalent cause of hydronephrosis, especially in young patients. The treatment paradigm for this condition has shifted from open to minimally invasive pyeloplasty. In the present study we describe our initial single centre experience with single port (SP) robot-assisted pyeloplasty (RAP) via periumbilical incision. MATERIAL AND METHODS: With the patient in a 60-degree left flank position, the SP system is docked with the Access port (Intuitive Surgical, Sunnyvale, CA, US) placed in a periumbilical 3 cm incision. Robotic instruments are deployed as follows: camera at 12 o'clock, bipolar grasper at 9 o'clock, scissors at 3 o'clock and Cadiere at 6 o'clock. After isolation and identification of the ureter and the ureteropelvic junction (UPJ), the ureter is transected at this level and then spatulated. Anastomosis is carried out by two hemicontinuous running sutures, over a JJ stent. RESULTS: Between 2021 and 2023, a total of 8 SP RAP have been performed at our institution, with a median (interquartile range, IQR) of 23 years (20.5-36.5). Intraoperative outcomes showed a median (IQR) OT of 210.5 minutes (190-240.5) and a median (IQR) estimated blood loss (EBL) of 50 mL (22.5-50). No postoperative complications were encountered, with a median (IQR) length of stay (LOS) of 31 hours (28.5-34). CONCLUSION: In the present study we evaluated the feasibility and safety of SP RAP. The observed outcomes and potential benefits, combined with the adaptability of the SP platform, hold promising implications for the application of SP system in pyeloplasty treatment.

Pedículo Renal: Análisis de sus Variantes / Renal Pedicle: Analysis of their Variants

Testut & Latarjet (1980), Bouchet & Cuilleret (1986), Latarjet & Liard (2005) y Rouvière & Delmas (2005) describen las relaciones intrínsecas del pedículo renal (PR) a partir de dos planos coronales, siendo la PER el elemento que limita entre ambos. Trivedi et al. (2011) demostró relaciones entre los elementos del PR que no coinciden con las descripciones aportadas por dichos autores.Conocer las posibles variantes en las relaciones intrínsecas del PR es de suma importancia en prácticas quirúrgicas como el trasplante renal (García de Jalón Martínez et al., 2003; Batista Hernández et al., 2010). Por lo tanto, el objetivo del presente trabajo fue analizar las variables relaciones entre los elementos que conforman el PR en la región yuxtahiliar del riñón. Se estudiaron 23 PR, formolizados al 10 % y provistos por el Equipo de Disección de la Segunda Cátedra de Anatomía de la Universidad de Buenos Aires. Se clasificaron los PR en dos grupos. En el Grupo I, las afluentes de origen de la vena renal (AOVR) se hallaban en el mismo plano coronal. En el grupo II, las AOVR se encontraban en diferentes planos coronales. Cada grupo fue subdividido en distintos patrones. Los patrones I y II, de mayor incidencia, fueron asociados al grupo I y los patrones III, IV y V al grupo II. En el patrón I, las AOVR eran anteriores a la pelvis renal (PER) y posteriores a la arteria prepiélica (APP). En el patrón II, las AOVR eran anteriores a la PER y a la APP. Los patrones I y II conforman el grupo I y presentaron mayor número de incidencia en nuestra investigación. Existen también variantes que inciden con menor frecuencia que dichos patrones, estas comprenden el grupo II de la clasificación planteada en el presente trabajo.

SUMMARY: Testut & Latarjet (1980), Bouchet & Cuilleret (1986), Latarjet & Liard (2005) y Rouvière & Delmas (2005) describe the intrinsic relationships of the renal pedicle (PR) from two coronal planes, the renal pelvis (PER) being the element that limits between both. Trivedi et al. (2011) showed relationships between the elements of the RP that do not coincide with the descriptions provided by these authors. Knowing the possible variants in the intrinsic relationships of the RP is of the utmost importance in surgical practices such as renal transplantation (García de Jalón Martínez et al., 2003). Therefore, the objective of this study is to analyze the variable relationships between the elements that make up the RP in the juxtahilar region of the kidney. 23 RP were studied, formalized at 10 % and provided by the Dissection Team of the Second Chair of Anatomy of the University of Buenos Aires. PRs were classified into two groups. In Group I, the tributaries of origin of the renal vein (RVOA) were in the same coronal plane. In group II, the AOVRs were in different coronal planes. Each group was subdivided into different patterns. Patterns I and II, with the highest incidence, were associated with group I and patterns III, IV and V with group II. In pattern I, the VROA were anterior to the renal pelvis (PER) and posterior to the prepelvic artery (PPA). In pattern II, AOVRs were prior to PER and APP. Patterns I and II make up group I and presented a higher number of incidence in our investigation. There are also variants that occur less frequently than these patterns, these comprise group II of the classification proposed in this work.

Laparoscopic Pyelolithotomy for treating urolithiasis in ectopic pelvic kidneys.

INTRODUCTION: The management of urolithiasis ectopic pelvic kidneys (EPK) can be challenging because of the aberrant anatomy (1-4). We demonstrate the step-by-step technique of the laparoscopic approach for treating urolithiasis in EPK. PATIENTS AND METHODS: Three men with EPK (2 left, 1 right) underwent laparoscopic pyelolithotomy through a transperitoneal approach. After establishing the pneumoperitoneum, the parietal peritoneum was opened at the parietal colic sulcus and the bowel displaced medially. The kidney was identified in the retroperitoneum and the renal pelvis exposed after removal of the perirenal adipose tissue. The renal pelvis was opened, and the stones were identified and retrieved with forceps in 2 cases and with a flexible nephroscope in 1 case. The renal pelvis was closed with a 3/0 running barbed suture. A DJ stent was placed in all patients. RESULTS: For the first time, a laparoscopic technique for treating stones in the ectopic kidney is demonstrated in detail. Mean patient age was 52.6 years (44-58). The mean stone size was 22.3 mm (20-24 mm). Stones were in the renal pelvis in 2 cases and in the inferior calyx in 1 case. Mean operative time was 146 minutes (135-155 min). Mean estimated blood loss was 116 ml (60-140 ml). No complications were observed. The mean hospital stay was 3 days. The DJ stents were removed after 3 weeks. All patients were stone free at the postoperative CT scan with a mean follow-up of 3.3 months (1-6 months). CONCLUSIONS: Laparoscopic pyelolithotomy can be an effective and reproducible minimally invasive technique for treating urolithiasis in EPK.

Laparoscopic pyeloplasty proficiency during a residency program after adoption of a standardized simulation training program is maintained during the COVID pandemic despite reduced surgery volume.

PURPOSE: To evaluate the effect of the standardized laparoscopic simulation training program in pyeloplasty, following its implementation and during the COVID-19 pandemic. MATERIAL AND METHODS: A retrospective chart review was performed at Hospital de Clínicas de Porto Alegre, a tertiary referral center in south Brazil, in which 151 patients underwent laparoscopic pyeloplasty performed by residents between 2006-2021. They were divided into three groups: before and after adoption of a standardized laparoscopic simulation training program and during the COVID-19 pandemic. The main outcome was a combined negative outcome of conversion to open surgery, major postoperative complications (Clavien-Dindo III or higher) or unsuccessful procedure, defined as need for redo pyeloplasty. RESULTS: There was a significant reduction in the combined negative outcome (21.1% vs 6.3%), surgical time (mean 200.0 min vs 177.4 min) and length of stay (median 5 days vs 3 days) after the adoption of simulation training program. These results were maintained during the COVID-19 pandemic (combined negative outcome of 6.3%, mean surgical time of 160.1 min and median length of stay of 3 days) despite a reduction in 55.4% of the surgical volume. CONCLUSION: A structured laparoscopic simulation program can improve outcomes of laparoscopic pyeloplasty during the learning curve.

Laparoscopic Ureterocalicostomy Technique.

PURPOSE: Ureterocalicostomy is a technique that was first described by Neuwirt in 1948 (1) The laparoscopic access was initiated in 2003 by Cherullo et al. (2), following the established principles of open surgery. In 2004, Gill et al. had two patients with UPJO treated with laparoscopic ureterocalicostomy, with success (3). In 2014, Arap et. al. presented a case series with good results in adults and children in our service (4). There are factors that prepare the surgeon for an ureterocalicostomy, such as the renal cortex thickness, although the decision is mainly taken during the procedure (5). MATERIAL AND METHODS: A 24 years-old female patient with right lumbar pain was referred to our institution. She already had a right open pyeloplasty two years ago. The CT scan presented a right hydronephrotic kidney, DMSA scan with 30% of relative function and a DTPA scan with an obstructive pattern. RESULTS: A laparoscopic ureterocalicostomy was performed due to the intra-operative findings (inferior kidney pole thickness and challenging access to the uretero-pelvic junction). The overall time was 130 minutes with no complications. The patient was discharged in two days and the double J was withdrawn in four weeks. The CT scan within one year demonstrates a reduction of the hydronephrosis. She had no more lumbar pain. CONCLUSION: In complex cases, the laparoscopic ureterocalicostomy proves to be a safe and efficient procedure, with a free tension-free anastomosis and the advantages of the laparoscopic access.

Are weight or age limits for pediatric laparoscopic pyeloplasty? Results of a multicentric study.

INTRODUCTION: Anderson-Hynes pyeloplasty is the technique of choice for the treatment of pyeloureteral junction obstruction (PUJO) with an excellent success rate. Minimally invasive surgery has become the standard of care for the management of PUJO in children. Although it has been comparable to the open approach at all levels, its diffusion or employment in younger children has not been widely adopted. Our aim is to evaluate laparoscopic pyeloplasty outcomes from international academic centers in children under 1 year of age, focusing on feasibility and outcomes including possible complications. MATERIALS AND METHODS: This is review of consecutive infants under 1 year of age who underwent laparoscopic pyeloplasty between 2009 and 2018 with more than 12 months of follow-up. Seven different training centers with different backgrounds participated in this study. Evaluation was carried out with ultrasound and renogram before and after surgery. Demographic data, perioperative characteristics, complications, and results are described and analyzed. RESULTS: Over 9 years, 124 transperitoneal laparoscopic Anderson-Hynes pyeloplasties were performed on 123 children under 1 year of age; 88 males and 35 females, with 1 case of bilateral PUJO. Of the 124 renal units, 86 were left-sided. Mean age at surgery was 6.6 months (1 week-12 months), with 56% (n = 70) done before 6 months of age. Mean weight at surgery was 6.8 kg (3-12 kg), with 59% (n = 73) weighing less than 8 kg. Mean operative time (skin-to-skin) was 150 min (75-330 min). After a mean follow-up of 46 months (12-84 months), 12 (9%) patients developed complications, with only 1 needing a redo pyeloplasty also done laparoscopically. One child, with deterioration in renal function, underwent nephrectomy. CONCLUSION: Laparoscopic pyeloplasty under 1 year of age and/or less than 12 kilos is feasible with lower complication rate. Furthermore, age younger than 6 months and weight less than 8 kg are no longer limiting factors for a successful pyeloplasty as shown by this multicentre study.

Robot-assisted modified bilateral dismembered V-shaped flap pyeloplasty for ureteropelvic junction obstruction in horseshoe kidney using KangDuo-Surgical-Robot-01 system.

PURPOSE: Horseshoe kidney (HSK) is the most common renal fusion anomaly, occurring in 0.25% of the population (1). It presents technical obstacles to pyeloplasty for ureteropelvic junction obstruction (UPJO) despite robotic assistance (2, 3). KangDuo-Surgical-Robot-01 (KD-SR-01), an emerging robotic platform in China, has yielded satisfactory outcomes in pyeloplasty (4, 5). We first describe our modified technique of robotic bilateral pyeloplasty for UPJO in HSK using KD-SR-01 system in the Lithotomy Trendelenburg position. MATERIALS AND METHODS: A 36-year-old man with HSK and bilateral UPJO suffered right flank pain due to renal calculi (Figure-1). Repeated double-J stent insertion and ureteroscopy lithotripsy did not relieve his symptoms. A robot-assisted modified bilateral dismembered V-shaped flap pyeloplasty was performed using KD-SR-01 system in the Lithotomy Trendelenburg position. RESULTS: Total operative time was 298 minutes with 50 ml estimated blood loss. There was no conversion to laparoscopic or open surgery. A follow-up of 14 months showed relieving symptoms and stable renal function. Cine magnetic resonance urography and computed tomography urography revealed improved hydronephrosis and good drainage. No intraoperative or postoperative complications occurred. CONCLUSIONS: It is technically feasible to perform a KD-SR-01-assisted modified bilateral dismembered V-shaped flap pyeloplasty in the Lithotomy Trendelenburg position for HSK. This procedure achieves managing UPJO on both sides without redocking the system and provides a wider operative field. In addition, it may be associated with better ergonomics, better cosmetic outcomes, and less possibility of postoperative bowel adhesion. However, further investigation is still warranted to confirm its safety, efficacy, and advantages over traditional procedures.

Latitudes and attitudes: A multinational study of laparoscopic pyeloplasty in children.

PURPOSE: The Anderson-Hynes technique has been the treatment of choice for primary ureteropelvic junction obstruction in children. Laparoscopic approach has shown similar outcomes to open, with advantages of shorter hospital stay and less pain. We reviewed the experience of 11 geographically diverse, tertiary pediatric urology institutions focusing on the outcomes and complications of laparoscopic pyeloplasty. MATERIALS AND METHODS: A descriptive, retrospective study was conducted evaluating patients undergoing Anderson-Hynes dismembered laparoscopic pyeloplasty. Centers from four different continents participated. Demographic data, perioperative management, results, and complications are described. RESULTS: Over a 9-year period, 744 laparoscopic pyeloplasties were performed in 743 patients. Mean follow-up was 31 months (6-120m). Mean age at surgery was 82 months (1 w-19 y). Median operative time was 177 min. An internal stent was placed in 648 patients (87%). A catheter was placed for bladder drainage in 702 patients (94%). Conversion to open pyeloplasty was necessary in seven patients. Average length of hospital stay was 2.8 days. Mean time of analgesic requirement was 3.2 days. Complications, according to Clavien-Dindo classification, were observed in 56 patients (7.5%); 10 (1%) were Clavien-Dindo IIIb. Treatment failure occurred in 35 cases with 30 requiring redo pyeloplasty (4%) and 5 cases requiring nephrectomy (0.6%). CONCLUSION: We have described the laparoscopic pyeloplasty experience of institutions with diverse cultural and economic backgrounds. They had very similar outcomes, in agreement with previously published data. Based on these findings, we conclude that laparoscopic pyeloplasty is safe and successful in diverse geographics areas of the world.

Development and Validation of a Laparoscopy Simulation Model of Pyeloplasty for Pediatric Patients.

Introduction: Given the extensive training required for laparoscopic pyeloplasty and the difficulties achieving this training, there is a need to recreate the activity in a controlled environment, but high-fidelity models are unavailable or expensive. Our objective was to develop a model of pyeloureteral junction stenosis, resembling the anatomical details and consistency of natural tissue, for a replicable, cheaper, and realistic simulation model of laparoscopic pyeloplasty in children. Materials and Methods: A three-dimensional, printed synthetic model was created from magnetic resonance urography. The model comprises a plastic kidney as the reusable structure and a silicone renal pelvis and ureter as the interchangeable structure. We evaluated realism and performance with surgeons and residents at different levels of training, comparing operative time and complications of the procedure. Results: Twenty-four participants were recruited; 41.7% had previous experience in laparoscopic pyeloplasty, with 5.5 years of experience in laparoscopic surgery (interquartile range [IQR] 2-7.75). There were no cases of stenosis, but leaks accounted for 41.7%. The procedure lasted 72 minutes (IQR 55-90), with significant differences according to the level of training (85 minutes for residents, 68 minutes for pediatric surgeons and urologists, and 40 minutes for laparoscopic surgeons; P: .011) and years of previous experience in laparoscopic surgery (P: .003). Conclusions: A high-fidelity, replicable, and low-cost pyeloureteral stenosis model was developed to simulate laparoscopic pyeloplasty in pediatric patients.

The influence of interstitial cells of Cajal density in the outcomes of pyeloplasty in adults: A prospective analysis.

PURPOSE: To evaluate if the density of interstitial cells of Cajal (ICC) in the ureteropelvic junction (UPJ) influences the outcomes of pyeloplasty in adults. METHODS: Twenty-three patients with the diagnosis of ureteropelvic junction obstruction (UPJO) that underwent laparoscopic dismembered pyeloplasty were included. ICC density was measured using immunohistochemistry reaction for c-KIT expression in the resected UPJ segment. Pyeloplasty outcome was evaluated by patient self-report pain, urinary outflow using DTPA renogram and hydronephrosis assessment using ultrasound (US) at 12 months of follow-up. A logistic regression analysis was performed to assess the association of pyeloplasty outcomes and ICC density. RESULTS: Low, moderate, and high ICC density were present in 17.4%, 30.4%, and 52.2% of the patients, respectively. Complete pain resolution was observed in 100%, 85.7%, and 75% of patients with low, moderate and high ICC density, respectively (p = 0.791). DTPA renogram improved in 75%, 85.7%, and 91.7% of patients with low, moderate and high ICC density, respectively (p = 0.739). Hydronephrosis improved in 25%, 85.7%, and 91.7% of patients with low, moderate and high ICC density, respectively (p = 0.032). CONCLUSIONS: Patients with high ICC density have a significant amelioration of hydronephrosis after pyeloplasty. However, ICC density is not associated with functional outcomes.

Multicenter comparative study of open, laparoscopic, and robotic pyeloplasty in the pediatric population for the treatment of ureteropelvic junction obstruction (UPJO).

INTRODUCTION: Dismembered open pyeloplasty described by Anderson and Hynes is the "gold standard" for the treatment of ureteropelvic junction obstruction. The aim of our study was to compare the results of open (OP) vs laparoscopic (LP) vs robotic (RALP) pyeloplasty. MATERIAL AND METHODS: A multicenter prospective review was conducted of pyeloplasty surgeries performed at five high-volume centers between 2014 and 2018. Demographic data, history of prenatal hydronephrosis, access type, MAG3 renogram and differential renal function, surgery time, length of hospital stay, and complication rate (Clavien-Dindo) were recorded. Access type was compared using the Kruskal-Wallis, Chi-square, or Fisher's exact tests. RESULTS: A total of 322 patients were included: 62 OP, 86 LP, and 174 RALP. The mean age was 8.13 (r: 1-16) years, with a statistically significant lower age (mean 5 years) in OP (p < 0.001). There were no significant differences in the distribution of the side affected. Operative time was 110.5 min for OP, 140 min for LP, and 179 min for RALP (p < 0.0001). Hospital stay was significantly shorter in the RALP group than in the other groups (p < 0.0001). There were no differences in postoperative complications and reoperations between the three groups. CONCLUSIONS: Minimally invasive surgery for the management of UPJO in children is gaining more acceptance, even in patients younger than 1-year-old. Operative time continues to be significantly shorter in OP than in LP and RALP. Hospital stay was shorter in RALP compared to the other techniques. No differences were found in complication rates, type of complications, and reoperation rate.

Nefroureterectomía radical lumboscópica con rodete vesical endoscópico, en cáncer urotelial de tracto urinario superior / Lumboscopic radical nephroureterectomy with endoscopic bladder cuff excision in an upper urinary tract urothelial tumor

Los carcinomas uroteliales son el 4to tumor más común. Pueden ubicarse en el tracto urinario inferior (vejiga y uretra) o en el tracto urinario superior (cavidades renales, pelvis renal y uréter). Presentamos una serie de 3 casos, con cuadro de hematuria macroscópica, documentando tumores uroteliales, realizándose en estos casos un abordaje lumboscópico de riñón y una resección endoscópica del rodete vesical. Se realiza nefroureterectomía lumboscópica con resección de rodete vesical endoscópica transuretral. Los 3 pacientes fueron egresados al segundo día posquirúrgico sin complicaciones y en los tres casos el rodete vesical sin evidencia de actividad tumoral, y actualmente en vigilancia con excelente resultados oncológicos. La nefroureterectomía lumboscópica con resección endoscópica del rodete vesical es una técnica reproducible en manos experimentadas, con iguales resultados oncológicos que el abordaje abierto.

Urothelial carcinomas are the 4th most common tumor. They can be located in the lower urinary tract (bladder and urethra) or in the upper urinary tract (renal cavities, renal pelvis, and ureter). We present a series of 3 cases, with a picture of macroscopic hematuria, documenting urothelial tumors, performing in these cases a lumboscopic approach to the kidney and an endoscopic resection of the bladder rim. Lumboscopic nephroureterectomy was performed with transurethral endoscopic bladder rump resection. The 3 patients were discharged on the second postoperative day without complications and in the three cases the bladder rim without evidence of tumor activity, and currently under surveillance with excellent oncological results. Lumboscopic nephroureterectomy with endoscopic resection of the bladder rim is a reproducible technique in experienced hands, with the same oncological results as the open approach.

Lower pole anatomy of horseshoe kidney and complete ureteral duplication: Anatomic and radiologic study applied to endourology.

PURPOSE: To analyze the 3-dimensional intrarenal anatomy of horseshoe kidneys (HK) and kidney with complete ureteral duplication (CUD), in polyester resin endocasts of the collecting system and in patients submitted to 3D computerized tomography scan (CT-scan). MATERIALS AND METHODS: We analyzed seven 3-dimensional polyester resin endocasts of the kidney collecting system obtained from 6 fresh adult cadavers (4 with unilateral CUD and 2 with horseshoe kidney) and CT-scan reconstruction images of kidneys from 24 patients: 6 patients with HK, 8 with CUD and 10 patients without renal anomalies that were used as controls. We analyzed the spatial distribution of the calices, the infundibula diameters, the angle between the lower infundibulum and the renal pelvis (LIP) and the angle between the lower infundibulum and the inferior minor calyces (LIICA). Measurements of the width and length of the inferior infundibulum and the infundibula of the minor calyces, as well as the angles (LIP and LIICA) were made with the aid of the LibreOffice 6.3 software. The data were analyzed with the IBM® SPSS® Statistics. RESULTS: There was no statistical difference in the inferior pole measurements between the groups with anomalies and the control group, both in polyester resin endocasts and CT-scan reconstruction images for LIP. When we compared the LIP in the CT-scan between HK versus CUD (p= 0.003), and HK versus the control group (p= 0.035), we observed statistical difference. CONCLUSIONS: The knowledge of spatial anatomy of lower pole is of utmost importance during endourologic procedures in patients with kidney anomalies. In the present study we observed that horseshoe kidneys had more restrictive anatomic factors in lower pole than the complete ureteral duplication.

Non-surgical management of vesicoureteral junction obstruction: a case report.

OBJECTIVE: To report the case of a pediatric patient with bilateral hydronephrosis due to vesicoureteral junction obstruction (VUJO) that was treated non-surgically and to discuss the approach of this anomaly. CASE DESCRIPTION: A 25-month-old boy was referred without complaints for consultation due to prenatal ultrasound showing kidneys with cysts. He was under antibiotic prophylaxis. No family history of kidney disease and/or inherited disorders was reported. Renal ultrasound (RUS) at 2 days of life showed bilateral hydronephrosis, thus ruling out the possibility of kidney cystic disease. Dynamic renal scintigraphy (DTPA) showed marked retention of the marker in the pyelocaliceal system bilaterally, with little response to diuretic drug. He was maintained under antibiotic prophylaxis, when a new RUS showed bilateral ureteral dilatation, abrupt stenosis in the ureterovesical transition region (0.2 cm caliber), moderate bilateral hydronephrosis, and slight renal cortical thickness, confirming the diagnosis of VUJO. At 2 years and 10 months of age, DTPA showed hydronephrosis and ureteral stasis in both kidneys secondary to stenosis at the vesicoureteral junction (VUJ) level, with preservation of kidney function and slow degree of emptying. We opted for a non-surgical approach. RUS at 10 years of age showed significant improvement of all parameters, with ureteral transverse diameter of 9 mm, preserved VUJ, and age-appropriate bilateral kidney development. COMMENTS: VUJO is a major cause of prenatal hydronephrosis and can trigger a deterioration of kidney function. Its treatment is still controversial but should take into account the importance of clinical follow-up and serial imaging evaluation.

Outcome of the treatment of hydronephrosis due to congenital ureteropelvic stenosis according to age at surgery.

BACKGROUND: Congenital kidney and urinary tract anomalies are the most common cause of chronic kidney disease in the first three decades of life. Stenosis of the ureteropelvic junction may cause dilation of the collecting system in the fetal kidney. This study aimed to determine hydronephrosis due to congenital ureteropelvic stenosis treatment outcome according to the age of the intervention. METHODS: We conducted a retrospective descriptive study that included pediatric patients with hydronephrosis secondary to ureteropelvic junction stenosis operated by the Anderson-Hynes open pyeloplasty method from 2010 to 2016. Patients were divided into two groups: group A, children < 1 year of age, and group B, children > 1 year of age. We analyzed ultrasonographic parameters, renal function, and clinical data. Inferential statistics were used with the Mann-Whitney U-test and X2 test. Intra-group data were assessed with the Wilcoxon test. RESULTS: We included 52 patients: group A (n = 16, 30%) and group B (n = 36, 70%). The male sex predominated, and mainly the left renal unit. The most important surgical finding was stenotic segment. The median right glomerular filtration rate was 24.1 mL/min (19.0-34.5) pre-surgical and 38.2 mL/min (35.9-41.09) post-surgical in group A (p = 0.028), and 28.4 mL/min (18.5-35.0) pre-surgical and 37 mL/min (35.7-46.0) post-surgical in group B (p = 0.003). The median left glomerular filtration rate was 30 mL/min (21.4-39.0) pre-surgical and 40.0 mL/min (37.7-44.6) post-surgical in group A (p = 0.005) and 18.4 mL/min (14.2-29.2) pre-surgical and 37 mL/min (33.1-38.5) post-surgical in group B (p < 0.001). CONCLUSIONS: Correction of ureteropelvic stenosis before one year of age results in better renal function than a later correction.

INTRODUCCIÓN: Las anormalidades congénitas del riñón y del tracto urinario son la causa más frecuente de enfermedad renal crónica en las primeras décadas de la vida. La estenosis de la unión ureteropiélica puede ocasionar restricción del flujo urinario desde la pelvis renal hacia el uréter, y es la causa más común de dilatación del sistema colector en el riñón fetal. El objetivo de este estudio fue determinar los resultados del tratamiento de la hidronefrosis por estenosis ureteropiélica congénita según la edad de la intervención. MÉTODOS: Se llevó a cabo un estudio retrospectivo descriptivo incluyendo pacientes pediátricos con hidronefrosis secundaria a estenosis de la unión ureteropiélica sometidos a pieloplastia abierta de Anderson-Hynes en el periodo 2010-2016. Se formaron dos grupos: A, pacientes < 1 año, y B, pacientes > 1 año. Se analizaron parámetros clínicos, ecosonográficos y de función renal. Se utilizó estadística inferencial con las pruebas U de Mann Whitney, χ2 y Wilcoxon. RESULTADOS: Se incluyeron 52 pacientes: 16 en el grupo A (30%) y 36 en el grupo B (70%). Predominó el sexo masculino, y principalmente la unidad renal izquierda. El hallazgo quirúrgico más importante fue el segmento estenótico. La mediana de la tasa de filtración glomerular derecha prequirúrgica fue de 24.1 ml/min (19.0-34.5) y la posquirúrgica fue de 38.2 ml/min (35.9-41.09) en el grupo A (p = 0.028), frente a 28.4 ml/min (18.5-35.0) y 37 ml/min (35.7-46.0), respectivamente, en el grupo B (p = 0.003). La mediana de la tasa de filtración glomerular izquierda prequirúrgica fue de 30 ml/min (21.4-39.0) y la posquirúrgica fue de 40.0 ml/min (37.7-44.6) en el grupo A (p = 0.005), frente a 18.4 ml/min (14.2-29.2) y 37 ml/min (33.1-38.5), respectivamente, en el grupo B (p < 0.001). CONCLUSIONES: La corrección de la estenosis ureteropiélica antes de 1 año de edad resulta en una mejor función renal que la corrección tardía.

Clinical and radiographic outcomes following salvage intervention for ureteropelvic junction obstruction

ABSTRACT Purpose: We aimed to assess failure rates of salvage interventions and changes in split kidney function (SKF) following failed primary repair of ureteropelvic junction obstruction (UPJO). Materials and Methods: A retrospective review of adult patients at an academic medical center who underwent salvage intervention following primary treatment for UPJO was performed. Symptomatic failure was defined as significant flank pain. Radiographic failure was defined as no improvement in drainage or a decrease in SKF by ≥7%. Overall failure, the primary outcome, was defined as symptomatic failure, radiographic failure, or both. Results: Between 2008-2017, 34 patients (median age 38 years, 50% men) met study criteria. UPJO management was primary pyeloplasty/secondary endopyelotomy for 21/34 (62%), primary pyeloplasty/secondary pyeloplasty for 6/34 (18%), and primary endopyelotomy/secondary pyeloplasty for 7/34 (21%). Median follow-up was 3.3 years following secondary intervention. Patients undergoing primary pyeloplasty/secondary endopyelotomy had significantly higher overall failure than those undergoing primary pyeloplasty/secondary pyeloplasty (16/21 [76%] vs. 1/6 [17%], p=0.015). Among patients undergoing secondary endopyelotomy, presence of a stricture on retrograde pyelogram, stricture length, and SKF were not associated with symptomatic, radiographic, or overall failure. Serial renography was performed for 28/34 (82%) patients and 2/28 (7%) had a significant decline in SKF. Conclusions: Following failed primary pyeloplasty, secondary endopyelotomy had a greater overall failure rate than secondary pyeloplasty. No radiographic features assessed were associated with secondary endopyelotomy failure. Secondary intervention overall failure rates were higher than reported in the literature. Unique to this study, serial renography demonstrated that significant functional loss was overall infrequent.

Clinical and radiographic outcomes following salvage intervention for ureteropelvic junction obstruction.

PURPOSE: We aimed to assess failure rates of salvage interventions and changes in split kidney function (SKF) following failed primary repair of ureteropelvic junction obstruction (UPJO). MATERIALS AND METHODS: A retrospective review of adult patients at an academic medical center who underwent salvage intervention following primary treatment for UPJO was performed. Symptomatic failure was defined as significant flank pain. Radiographic failure was defined as no improvement in drainage or a decrease in SKF by ≥7%. Overall failure, the primary outcome, was defined as symptomatic failure, radiographic failure, or both. RESULTS: Between 2008-2017, 34 patients (median age 38 years, 50% men) met study criteria. UPJO management was primary pyeloplasty/secondary endopyelotomy for 21/34 (62%), primary pyeloplasty/secondary pyeloplasty for 6/34 (18%), and primary endopyelotomy/secondary pyeloplasty for 7/34 (21%). Median follow-up was 3.3 years following secondary intervention. Patients undergoing primary pyeloplasty/secondary endopyelotomy had significantly higher overall failure than those undergoing primary pyeloplasty/secondary pyeloplasty (16/21 [76%] vs. 1/6 [17%], p=0.015). Among patients undergoing secondary endopyelotomy, presence of a stricture on retrograde pyelogram, stricture length, and SKF were not associated with symptomatic, radiographic, or overall failure. Serial renography was performed for 28/34 (82%) patients and 2/28 (7%) had a significant decline in SKF. CONCLUSIONS: Following failed primary pyeloplasty, secondary endopyelotomy had a greater overall failure rate than secondary pyeloplasty. No radiographic features assessed were associated with secondary endopyelotomy failure. Secondary intervention overall failure rates were higher than reported in the literature. Unique to this study, serial renography demonstrated that significant functional loss was overall infrequent.