Endoscopic management and the role of double stenting for primary obstructive megaureters

Advancements in Surgical Management of Megaureters

PURPOSE OF REVIEW

To review and describe the recent evolution of surgery for the various types of pediatric megaureter.

RECENT FINDINGS

Megaureter management first relies on determining the underlying cause, whether by obstruction, reflux, or a combination, and then setting appropriate surgical indications because many cases do not require surgery as shown by observation studies. Endoscopic balloon dilation has been on the rise as a major treatment option for obstructive megaureter, while refluxing megaureters can also be treated by laparoscopic and robotic techniques, whether extravesically or transvesicoscopically. During ureteral reimplantation, tapering is sometimes necessary to address the enlarged ureter, but there are also considerations for not tapering or for tapering alternatives. Endoscopic and minimally invasive surgeries for megaureter have been the predominant focus of recent megaureter literature. These techniques still need collaborative prospective studies to better define which surgeries are best for patients needing megaureter interventions.

Risk Factors for Failure of Endoscopic Balloon Dilatation of Primary Obstructive Megaureter: Single-Center 12-Year Experience with 123 Cases

Purpose: To review our experience with >100 patients with primary obstructive megaureter (POM) undergoing endoscopic balloon dilatation (EBD) and a follow-up of up to 12 years and determine potential risk factors for failure. Our hypothesis is that EBD allows for long-term treatment in >80% of patients, and its effectiveness decreases in more severe cases. Methods: This is a retrospective study of 123 consecutive patients (131 ureters) undergoing EBD from 2009 to 2021. Indications for EBD included symptoms, worsening dilatation, and/or renal function impairment. Clinical characteristics, complications, and outcomes, including those in the patients with >5-year follow-up, were described. Preoperative and intraoperative markers of severity chosen a priori were tested as risk factors for failure. Failure was defined as the need for ureteral reimplantation after EBD. Results: EBD was feasible in 121 of 123 (98%) patients, regardless of age. After a median follow-up of 38 (9-143) months, EBD was effective in 84.5% of cases. Failures generally occurred in the 1st year after EBD and were seldom associated with permanent loss of renal function. Of the 66 patients with follow-up >5 years, EBD was effective in 56 patients. No preoperative characteristic proved to be a risk factor for failure. The intraoperative absence of a ring was the only significant risk factor for failure, odd ratio 117.86 (95% confidence interval 6.27-2215.84). Conclusions: EBD was feasible and definitive treatment in 85% of our cases, regardless of age. Since this study did not identify preoperative factors to help the clinicians in patient selection, we consider EBD a viable initial procedure in all patients with POM who require surgical intervention, especially in infants.

Endoscopic treatment of primary obstructive megaureter with high pressure balloon dilation in infants

INTRODUCTION AND OBJECTIVE

Ureteral reimplantation of the dilated ureter in infants is challenging; however, some patients with primary obstructive megaureter (POM) in this age group require intervention due to clinical or radiological progression. We sought to determine if high pressure balloon dilation (HPBD) can serve as a definitive treatment for POM in children under one year of age, or as a temporizing measure until later reimplantation.

MATERIALS AND METHODS

All patients from a single institution who underwent HPBD between October 2009 and May 2022 were retrospectively reviewed. Patients were excluded if older than 12 months or diagnosed with neurogenic bladder, posterior urethral valves, or obstructed refluxing megaureter. Patients with prior surgical intervention at the ureterovesical junction were excluded. Indications for surgery included progressive hydroureteronephrosis or urinary tract infection (UTI). Balloon dilation was performed via cystoscopy with fluoroscopic guidance, followed by placement of two temporary ureteral stents. Primary outcomes were improvement or resolution of megaureter and rates of subsequent reimplantation. Secondary outcomes included total number of anesthetics and postoperative UTIs.

RESULTS

Fifteen infants with median age of 7.6 months (IQR 3.8-9.7) underwent HPBD. Twelve (80%) patients were detected prenatally and 3 (20%) after a UTI. Indication for surgery was progressive hydroureteronephrosis in 10 patients (67%) and UTI in five (33%). All had SFU grade 3 or 4 hydronephrosis on preoperative ultrasound and median distal ureteral diameter was 13 mm. Median follow up was 2.9 years. Twelve (80%) succeeded with endoscopic treatment: 7 patients had an undetectable distal ureter on ultrasound at last follow-up, 5 were improved with median distal ureteral diameter of 7 mm. Three patients (20%) required ureteral reimplantation due to progressive dilation, all with grade 4 hydronephrosis and distal ureteral diameters were 11, 15, and 21 mm. Six patients (40%) required two anesthetics to complete endoscopic treatment. Among those, 4 patients required initial stent placement for passive dilation followed by a second anesthetic for HPBD weeks later. Two patients underwent repeat HPBD following postoperative proximal migration of the ureteral stents. All 15 patients had an additional anesthetic for removal of stents. Five patients (33%) were treated for a symptomatic UTI (4 febrile, 1 afebrile) with the stents indwelling but there were no UTIs in the group following stent removal.

CONCLUSION

Balloon dilation is a practical option for treatment of POM in infants, and in most cases (80%) avoids subsequent open surgery (over median 2.9 years of follow-up).

Spontaneous resolution and the role of endoscopic surgery in the treatment of primary obstructive megaureter: a review of the literature

The megaureter accounts for almost a quarter of all urinary tract dilations diagnosed in utero and is the second leading cause of hydronephrosis in newborns, following pyeloureteral junction obstruction. The current standard treatment for progressive or persistent, symptomatic primary obstructive megaureter is ureteral anti-reflux reimplantation, which can be associated with ureteral remodeling or plication. Due to the associated morbidity, postoperative recovery challenges, and the complications that may arise from the open surgical approach, there has been a natural inclination towards validating new minimally invasive techniques. This study reviews the literature, extracting data from three major international databases, from 1998 to 2022. Out of 1172 initially identified articles, only 52 were deemed eligible, analyzing 1764 patients and 1981 renal units. Results show that 65% of cases required surgical intervention, with minimally invasive techniques constituting 56% of these procedures. High-pressure endoscopic balloon dilation was the preferred endourologic technique. The degree of ureterohydronephrosis is considered one of the factors indicating the need for surgery. There is an inverse relationship between the diameter of the ureter and the likelihood of spontaneous resolution. Conditions such as renal hypoplasia, renal dysplasia, or ectopic ureteral insertion strongly indicate a poor prognosis. Endoscopic surgical techniques for treating primary obstructive megaureter can be definitive, firstline treatment options. In selected cases, they might be at least as effective and safe as the open approach, but with advantages like quicker recovery, fewer complications, shorter hospital stays, and reduced costs.

Endoscopic balloon dilation of primary obstructive megaureter: is fluoroscopic guidance necessary?

OBJECTIVE

To compare the long-term effectiveness, complications, and outcomes of primary obstructive megaureter (POM) treated by endoscopic balloon dilation under fluoroscopic guidance versus not using radioscopy during the procedure.

PATIENTS AND METHODS

A comparative study between POM cases treated at our institution by endoscopic balloon dilation (EBD) under fluoroscopic guidance (FG) (n = 43) vs no fluoroscopic guidance (NFG) (n = 48) between the years 2004 and 2018 was conducted. The procedure in FG consisted of performing a retrograde pyelography before dilation. Then, a guidewire is introduced to the renal pelvis, and the dilation of the vesicoureteral junction is performed using high-pressure balloon catheters under fluoroscopic vision. Finally, a double-J stent is placed between the renal pelvis and bladder. The procedure in NFG was performed exclusively under cystoscopic vision without radiological exposure. Complications, outcomes, and success rates were analyzed using Spearman's correlation test. Mean follow-up was 12.5 ± 2.2 years in FG and 6.4 ± 1.3 years in NFG.

RESULTS

MAG-3 showed significant differences in renal drainage before and after endoscopic treatment in both groups (p < 0.001 T-test). Statistical analysis did not reveal differences between groups in initial technical failure (r: - 0.035, p = 0.74), early postoperative complications (r: - 0.029, p = 0.79), secondary VUR (r: 0.033, p = 0.76), re-stenosis (r: 0.022, p = 0.84), long-term ureteral reimplantation (r: 0.065, p = 0.55), and final outcome (r: - 0.054, p = 0.61). The endoscopic approach of POM had a long-term success rate of 86.5% in FG VS 89.6% in NFG.

CONCLUSIONS

Endoscopic balloon dilation of POM can be done with no radiation exposure with similar results, effectiveness, and outcomes.

High-pressure balloon dilatation of primary obstructive megaureter in children: a systematic review

OBJECTIVE

We aimed to evaluate the effectiveness and complication rates of endoscopic high-pressure balloon dilatation (HPBD) in treating primary obstructive megaureter (POM) in children based on current literature. Specifically, we wanted to clarify the evidence on the use of HPBD in children under one year of age.

METHODS

A systematic search of the literature was performed via several databases. The preferred reporting items for systematic reviews and meta-analyses guidelines were followed. The primary outcomes studied in this systematic review were the effectiveness of HBPD in relieving obstruction and reducing hydroureteronephrosis in children. The secondary outcome was to study the complication rate of endoscopic high-pressure balloon dilatation. Studies that reported one or both of these outcomes (n = 13) were considered eligible for inclusion in this review.

RESULTS

HPBD significantly decreased both ureteral diameter (15.8 mm [range 2-30] to 8.0 mm [0-30], p = 0.00009) and anteroposterior diameter of renal pelvis (16.7 mm [0-46] to 9.7 mm [0-36], p = 0.00107). The success rate was 71% after one HPBD and 79% after two HPBD. The median follow-up time was 3.6 years (interquartile range 2.2-6.4 years). A complication rate of 33% was observed, but no Clavien-Dindo grade IV-V complications were reported. Postoperative infections and VUR were detected in 12% and 7.8% of cases, respectively. For children under one year of age, outcomes of HPBD seem to be similar to those in older children.

CONCLUSIONS

This study indicates that HPBD appears to be safe and can be used as the first-line treatment for symptomatic POM. Further comparative studies are needed addressing the effect of treatment in infants, and also long-term outcomes of the treatment. Due to the nature of POM, identifying those patients who will benefit from HPBD remains challenging.

Endoscopic balloon dilatation for the treatment of primary obstructive megaureter <24 months of age: Does the size of the balloon influence results?

INTRODUCTION

Endoscopic balloon dilatation (EBD) can be performed with different catheters and its durability is still controversial. This study aimed to compare long-term results of EBD performed <24 months of age using balloons of 4 mm vs. 6 mm in diameter.

MATERIALS AND METHODS

Retrospective study of consecutive patients with unilateral primary obstructive megaureter (POM) undergoing EBD <24 months of age by two surgeons from 01/2009 to 12/2020. The technique was consistent, but for balloon diameter, which was 4 mm in group A vs. 6 mm in group B. End-points included peri-operative complications, success rate (improving dilatation and non-obstructive drainage on 9-month scintigraphy), and long-term outcome (need for reimplantation and diameter of retrovesical ureter at last ultrasound).

RESULTS

The procedure was completed in all planned patient. Group A included 15 patients and Group B 30 patients. Groups were not significantly different for age (p < 0.09), gender (p < 0.1), laterality (p < 0.7), and preoperative median ureteral diameter (p = 0.08). No perioperative complications occurred. Four group A patients required a cutting balloon to achieve a satisfactory dilatation of the vesicoureteral junction (p = 0.009). After a median (range) follow-up of 70 (19-155) months, success rate was 73.3% vs. 83.3% (p = 0.45), 4/15 group A and 5/30 group B patients required reimplantation within 2 years of EBD. In successful cases, median (range) ureteral diameter at last follow-up was 6 (0-17) mm vs. 5 (0-14) mm, which was significantly better than preoperative value (p = 0.003 and p < 0.001, respectively), but not significantly different (p = 0.8) between groups.

DISCUSSION

EBD is an umbrella term that encompasses many technical variations, which can be key for success. Although limited by the small numbers and the comparison of patients treated over two subsequent periods, this is the first study focusing on the role of balloon size.

CONCLUSIONS

The diameter of the balloon did not influence significantly long-term results, but the 6 mm balloon slightly increased the success rate of EBD to 83.3% and eliminated the need for cutting balloons to achieve a satisfactory dilatation.

Postoperative JJ stent is not necessary after balloon high-pressure endoscopic dilatation of primary obstructive megaureter

INTRODUCTION

A wide range of surgical interventions have been described for the management of primary obstructive megaureter (POM). Endoscopic balloon dilatation has been developed through last decades as a minimally invasive alternative to classic surgery.

OBJECTIVE

To assess the need for placement of a double J stent after endoscopic balloon dilatation procedure, by comparing the post-operative related outcomes with and without double J placement. Secondary outcome was the success rate, considering the need for further procedure after endoscopic balloon dilatation and the improvement of the ureteral diameter in the two groups.

STUDY DESIGN

Historical retrospective comparison of children treated by endoscopic dilatation for POM, with post-operative JJ stent left in place (2012-2014) or without ureteral JJ stent (since 2015). Post-operative complications were reported following Clavien-Dindo grading system and compared between the two groups. Success rate was defined as absence of need for further surgical reimplantation. Ureteral diameters on preoperative and postoperative renal ultrasounds were compared.

RESULTS

Endoscopic dilatations were performed in 42 patients for 46 renal units during the study period. There was a significantly higher rate of post-operative complications in the group with JJ stenting compared to the group without double J stenting regarding all Clavien-Dindo grades (56% vs 15%, p = 0.014) and Clavien-Dindo grade III only (31% vs 0%, p = 0,0051) (Figure). The success rate was similar in the JJ group (75%, F-up: 70 months [13-101]) and the no JJ group (81%, F-up: 26 months [12-95]). There was a significant improvement of US renal pelvis and ureter dilatation in both groups, with a median follow-up of 35.5 months [12-101].

DISCUSSION

The overall rate of complications was slightly higher than in other reports and higher in the JJ group regarding Clavien-Dindo grade III complications. The success rate was comparable to previous studies reviewing endoscopic dilatations and equivalent in the two groups.

CONCLUSION

In our study, the omission of postoperative ureteral drainage by a JJ stent after endoscopic balloon dilatation of POM did not increase post-operative complications rate without demonstrable impact on the success rate.

Preliminary Outcomes of Different Tactics of Ureteral Stent Placement in Patients with Ureteral Stricture Undergoing Balloon Dilatation: Experience from a Large-Scale Center

Purpose

Our aim is to demonstrate the optimal number of ureteral stent placements in patients with a ureteral stricture (US) after balloon dilatation (BD).

Methods

A retrospective analysis of 213 patients who underwent BD from 2011 to 2019 was conducted. All statistical analyses were completed by software SPSS 25.0.

Results

Of the patients enrolled, 119 were males and 94 were females. The average age was 44.71 years. One month after stent removal, the overall success rate of ureteral stent placement was 76.99%, and the success rates of single, double, and triple stent groups were 81.7%, 70.3%, and 79.3%, respectively. Six months after stent removal, the overall success rate was 61.9%, and the success rates of the three groups were 61.7%, 52.7%, and 74.1%, respectively. Twelve months after stent removal, the overall success rate was 55.9%, and the success rates of the three groups were 51.9%, 48.6%, and 70.7%, respectively. During indwelling of the stents, the proportions of severe bladder irritation symptoms in the three groups were 13.6%, 16.2%, and 20.7%, respectively. Multivariate analysis indicated the length of US and the time and number of ureteral stent placements were independent risk factors of the treatment effect at 6 months and 12 months after stent removal. Patients in the triple stent group had a better prognosis when compared to those in the single or double stent group.

Conclusion

The long-term effect of three stents was better than that of single and double stents, but the success rate of treatment reduced gradually over time.

Minimal-invasive management of urological complications after kidney transplantation

Kidney transplantation represents the gold standard treatment option for patients with end-stage renal disease. Improvements in surgical technique and pharmacologic treatment have continuously prolonged allograft survival in recent years. However, urological complications are frequently observed, leading to both postoperative morbidity and putative deterioration of allograft function. While open redo surgery in these patients is often accompanied by elevated surgical risk, endoscopic management of urological complications is an alternative, minimal-invasive option. In the present article, we reviewed the literature on relevant urological postoperative complications after kidney transplantation and describe preventive approaches during the pre-transplantation assessment and their management using minimal-invasive approaches.

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.

Long-Term Outcomes of Two Ipsilateral vs Single Double-J Stent After Laser Endoureterotomy for Bilharzial Ureteral Strictures

Background: Laser endoureterotomy became a preferable choice for managing benign ureteral strictures. Ureteral stricture caused by bilharzias is characterized by focal destruction of ureteral musculature, ending by fibrosis, making it poor responder to endoureterotomy. There is no consensus about the ideal ureteral stent size after endoureterotomy. However, many researches recommend larger stents caliber (12-14F). We assess long-term efficacy of insertion of two ipsilateral Double-J stents vs single Double-J stent after laser endoureterotomy for bilharzial ureteral stricture. Materials and Methods: Within 4 years, 70 patients underwent retrograde laser endoureterotomy for bilharzial ureteral stricture (diagnosed by positive history of bilharziasis, positive serology test, and/or bilharzial cystoscopic finding). Patients with history of stone, urologic or pelvic surgery were excluded. Patients were randomized into two groups: the first group (35 patients) received ipsilateral two Double-J (7F each) postendoureterotomy, whereas the second group (35 patients) received one Double-J (7F). Double-Js were removed after 8 weeks. Follow-up was done regularly by clinical interpretation and imaging studies. Patients' characteristics, operative data, and postoperative outcomes (subjectively and objectively) were compared in both groups. Results: Sixty-three patients completed follow-up >18 months, mean follow-up 30 ± 4 months [19-41], and mean stricture length 1.4 ± 0.6 cm [0.5-3.0], with no statistical significance between both groups. Success proved by relief of symptoms and radiographic resolution of obstruction. The overall success rate was significantly better in 2-Double-J group than in 1-Double-J group (83.9% vs 53.1%) p = 0.009, and also for stricture >1.5 cm (85.7% vs 38.5%) p = 0.018, respectively. Conclusions: Insertion of two ipsilateral Double-J, after laser endoureterotomy for bilharzial ureteral stricture associated with long-term success rate better than insertion of 1-Double-J, especially for stricture segment >1.5 cm.

High-pressure balloon dilatation in children: our results in 30 patients with POM and the implications of the cystoscopic evaluation

Primary Obstructive Megaureter (POM) is a common cause of hydronephrosis in children with spontaneous resolution in most cases. High-Pressure Balloon Dilatation (HPBD) has been proposed as a minimally invasive procedure for POM correction in selected patients. The aim of the paper is to review our experience with HPBD in patients with POM. We performed a retrospective study in a single Centre collecting data on patients' demographics, diagnostic modalities, surgical details, results and follow-up. In particular, the endoscopic aspect of the orifice permitted the identification of 3 patterns: adynamic ureteral segment, stenotic ureteric ring and pseudoureterocelic orifice. We performed HPBD in 30 patients over 6 years. We had 23 patients with adynamic distal ureteral segment (type 1), 4 with stenotic ring (type 2) and 3 with ureterocelic orifice (type 3). In 3 patients (10%) the guidewire did not easily pass into the ureter requiring ureteral stenting or papillotomy. Post-operative course was uneventful. Five patients (3 pseudoureterocelic) required open surgery during follow-up. HPBD for the treatment of POM is a safe and feasible procedure and it can be a definitive treatment of POM. Complications are mainly due to double J stent and none of our patients had symptoms related to vescico-ureteral reflux. The aspect of the orifice, identified during cystoscopy, seems to correlate with the efficacy of the dilatation: type 1 and 2 are associated with good and excellent results respectively; type 3 do not permit dilatation in almost all cases requiring papillotomy. HPBD can be performed in selected patients of all paediatric ages as first therapeutic line. The presence of a pseudoureterocelic orifice or long stenosis might interfere with the ureteral stenting and seems associated with worse outcomes.

Laparoscopic Extravesical Reimplantation in Children with Primary Obstructive Megaureter

Introduction: Conservative management of primary obstructive megaureter (POM) appears as the best option in patients with adequate ureteral drainage. Nevertheless, surgical intervention is indicated in cases of recurrent urinary tract Infections (UTIs), deterioration of split renal function, and significant obstruction. The gold standard includes: Ureteral reimplantation with or without tapering by open approach. Our objective is to report our results in the treatment of POM by Laparoscopic-Assisted Extracorporeal Ureteral Tapering Repair (EUTR) and Laparoscopic Ureteral Extravesical Reimplantation (LUER) and to evaluate the efficacy and security of this procedure. Materials and Methods: From January 2011 to January 2018 a retrospective study was carried out by reviewing the clinical records of 26 patients diagnosed with POM. All patients underwent laparoscopic ureteral reimplantation following Lich Gregoir technique. In cases of ureteral tapering, an EUTR was performed with Hendren technique. Results: In all patients LUER and EUTR were performed without conversion. No ureteral tapering was necessary in six patients. There were no intraoperative complications. At 3 months in postoperative, 1 patient presented a febrile UTI, and subsequently, a vesicoureteral reflux (VUR) grade III was diagnosed by voiding cystourethrogram. In this case, a redo laparoscopic surgery was performed. After long-term follow-up, all patients were asymptomatic without recurrence of POM or VUR. Conclusion: Laparoscopic-assisted EUTR and LUER following Lich Gregoir technique for POM constitutes a safe and effective option, with a success rate similar to that of open procedure. Nevertheless, larger randomized prospective trials and long-term follow-up are required to validate this technique.

Management of Primary Obstructive Megaureter by Endoscopic High-Pressure Balloon Dilatation. IDEAL Framework Model as a New Tool for Systematic Review

Introduction: Therapeutic management of primary obstructive megaureter (POM) requiring surgery has been under debate for the last 15 years especially regarding the outcomes of endoscopic techniques compared to most traditional approaches. This review aims to analyze endoscopic High-Pressure Balloon Dilatation (HPBD) using the IDEAL model, a five-stage framework that describes surgical innovations (Idea, Development, Exploration, Assessment, and Long-term Study) and provides recommendations for a rigorous stepwise surgical research pathway. This model has been developed and demonstrated its value in evaluating surgical innovations assessing data quality and providing relevant information for the optimal design and feasibility of research in surgery. Materials and Methods: A systematic review of the published series of endoscopic HPBD in patients with POM was done using the IDEAL model as a tool to assess evidence quality. Reported clinical outcomes are also analyzed and reviewed. Results: The analysis of the results of the systematic assessment of the reported cohort of patients treated with HPBD for POM that the technique up to date is in stage 2a and stage 2b, or development. Evidence quality among the reported cohorts of patients with POM treated with HPBD is adequate, although systematization and standardization should be improved. Clinical outcomes of HPBD in the management of POM consistently show a 87.7% success rate with a negligible operative complication rate once "learning curve" has been surpassed. Symptomatic vesicoureteral reflux (VUR) is the main reason for ureteric reimplantation, but asymptomatic VUR does not seem to influence clinical outcome. Conclusions: The IDEAL framework and recommendations have allowed a systematic analysis of the evidence quality of the reported experience in the management of children with POM with HPBD of the vesicoureteral junction. The available evidence demonstrates that HPBD is an effective treatment for patients with POM, with a long-term success rate of 87.7% with very low morbidity. Future research mandates a standardization of data reporting, "ideally" following IDEAL recommendations, that would be required for any intervention and facilitate comparative analysis.

Endoscopic management of primary obstructive megaureter in pediatrics

AIMS

The aims of this study were to evaluate the efficacy and safety of endoscopic treatment of primary obstructive megaureter in children, and to assess its long-term outcome.

METHODS

Case files of 35 children who had endoscopic treatment of symptomatic primary obstructive megaureter between 2006 and 2016 were retrospectively analyzed. All children had ureterovesical junction dilatation with one or more ureteral dilators, and insertion of a JJ stent. An analysis of the case files and a comparison between pre- and postoperative ultrasound and scintigraphy findings were performed.

RESULTS

The study population consisted of 22 boys and 13 girls aged between 2 months and 16 years. The follow-up period ranged from 8 months to 10 years. Twenty-one children (60%) were under 2 years at the time of treatment. The average duration of JJ stenting was 7 weeks (3-16 weeks). Thirty-four of 35 children (97%) were considered definitively cured, that is, asymptomatic with preserved renal function. Two children required open surgery for a failed endoscopic treatment procedure. Secondary reimplantation surgery was only necessary in one case (1/35) after technically satisfactory endoscopic treatment. Twelve of 35 children had a complication, including two Clavien III complications. Comparison of pre- and postoperative ultrasonography showed a significant decrease in ureteral diameter in 31 cases. Postoperative scintigraphy showed a significant improvement in the ureteral leaking curve in 20 children.

CONCLUSION

In our experience, endoscopic treatment of congenital obstructive megaureter in pediatrics seems to be safe and effective. It is proposed as a first-line treatment for children requiring an intervention, even for young children under 2 years.

Endoscopic Management of Primary Obstructive Megaureter: A Systematic Review

BACKGROUND

The gold standard treatment for primary obstructive megaureter (POM) with declining renal function, worsening obstruction, or recurrent infections is ureteral reimplantation with or without tapering. In infants, open surgery can be technically demanding and associated with significant morbidity. We conducted a systematic review of the literature with special interest in endoscopic management of POM and its outcomes.

MATERIALS AND METHODS

A search was conducted of the MEDLINE/Ovid, PubMed, Embase, and Web of Science databases. Only full-text articles written in the English language and involving greater than one reported pediatric case per publication were included. Two authors independently extracted data and assessed strength of evidence for each study.

RESULTS

We found 11 retrospective and 1 prospective, single institution case series that met selection criteria, describing 222 patients with 237 obstructed renal units. Mean age at time of surgery was 24.6 months. The most common endoscopic approaches were cystoscopy+high-pressure balloon dilation+Double-J ureteral stent placement (49.5%), cystoscopy+incisional ureterotomy+Double-J ureteral stent placement (27.8%), and cystoscopy+Double-J ureteral stent placement (18.9%). For all approaches and age groups, anatomic and functional success rates were 79.3% (146/184) and 76.7% (132/172), respectively. Anatomic success rates were highest in children ≥12 months of age (82.3%, 117/142). Endoscopic retreatment was performed in 15.1% of cases with a 36.7% overall surgical reintervention rate. Forty-one ureters progressed to ureteral reimplantation. Complications were generally mild (Clavien-Dindo Grades I-II), but 12 ureters did develop vesicoureteral reflux. Mean follow-up period was 3.2 years.

CONCLUSIONS

Endoscopic management for persistent or progressive POM in children ≥12 months of age is a minimally invasive alternative to ureteral reimplantation with modest success rates. In infants, it may best be utilized as a temporizing procedure. Approximately one-third of patients require surgical reintervention.

Endoscopic balloon dilatation in primary obstructive megaureter: Long-term results

BACKGROUND

Open neoureterocystostomy is the traditional surgical treatment for primary obstructive megaureter (POM). Endoscopic balloon dilation is a new minimally invasive alternative. It has been shown to be a safe and effective endoscopic procedure over short-term follow-up; however, few studies have shown its long-term efficacy.

OBJECTIVE

The aim of this study was to evaluate the long-term results and complications of balloon dilation for the treatment of primary obstructive megaureter in infants.

MATERIALS AND METHOD

A retrospective review was performed of patients with primary obstructive megaureter treated with balloon dilation. The diagnosis was made through ultrasonography, diuretic isotopic renogram, and voiding cystourethrogram (VCUG). The indications for surgery were: worsening hydronephrosis, renal function impairment, and recurrent urinary tract infections (UTI). All patients were followed 3 months after the endoscopic procedure with ultrasonography and MAG-3 renogram, and 6 months after surgery with VCUG and ultrasonography. Annual ultrasound and clinical follow-up were performed until present time.

RESULTS

Seven boys and six girls were treated (median age 9 months, range 2-24). Ten patients had a prenatal diagnosis of hydronephrosis, and the diagnoses was made after UTI in three patients. No intraoperative complications were observed. One double-J stent was replaced after endoscopic procedure for malpositioning, and four patients developed UTIs after surgery. All patients had non-obstructive MAG-3 diuretic renogram 6 months after surgery. The mean washout on the renogram and the ultrasound pelvic diameter showed pre-operative and postoperative statistical differences (Summary Table). All patients maintained their results without recurrence or any other complications in the long-term follow-up. The median follow-up was 10.3 years (range 4.7-12.2).

DISCUSION

In 2014, Aparicio et al. first described balloon dilation being used as a definitive treatment for primary obstructive megaureter in infants. Bujons et al. also presented 20 cases with a mean follow-up of 6.9 years. The current study is the largest to date, with a median follow-up of 10.2 years. It demonstrated the value of balloon dilation as a definitive treatment for POM. Despite these results, it was difficult to establish endoscopic balloon dilation as a definitive treatment for POM, due to the absence of long-term studies like the current one.

CONCLUSION

Balloon dilation can be a safe and effective endoscopic procedure for the treatment of primary obstructive megaureter in infants, and has shown good outcomes in long-term follow-up. More studies are needed to demonstrate these results.

Long-Term Outcomes in Primary Obstructive Megaureter Treated by Endoscopic Balloon Dilation. Experience After 100 Cases

Aim: To assess long-term effectiveness, complications, and outcomes of primary obstructive megaureter (POM) treated by endoscopic balloon dilation (EBD) in the largest series reported. Patients and Methods: Hundred POM in 92 consecutive patients were treated by EBD between years 2004 and 2016. A total of 79 POM (73 patients) with more than 18 months of follow-up after treatment have been analyzed. EBD of the vesicoureteral junction was performed with semicompliant high-pressure balloon catheters (2.7FG) with minimum balloon diameter of 5 mm, followed by temporary Double-J stent placement. Follow-up protocol included periodical clinical reviews, US and MAG-3 renogram scans. Results: Median age at surgery was 4 months (15 days-3.6 years), with median operating time of 20 min (10-60) and hospital stay of 1 day (1-7). Initial renal function was preserved in all patients with significant improvement in renal drainage on the MAG-3 diuretic renogram after endoscopic treatment (p < 0.001 T-test). Significant post-operative differences were observed in hydronephrosis grade and ureteral diameter that were maintained in the long-term (p < 0.001 T-test). Endoscopic approach of POM had a long-term success rate of 87.3%, with a mean follow-up of 6.4 ± 3.8 years. Secondary VUR was found in 17 cases (21.5%), being successfully treated by endoscopic subureteral injection in 13 (76.4%). Nine cases developed long-term re-stenosis (12.2%) that were successfully treated with a new EBD in 8. Endoscopic management of POM failed in 10 cases (12.7%) that required ureteral reimplantation. Five were early failures (4 intraoperative technical problems and 1 double-J stent migration with severe re-stenosis), and 5 long-term (4 persistent VUR and 1 re-stenosis recurrence). Conclusion: EBD has shown to be an effective treatment of POM with few complications and good outcomes at long-term follow up. Main complication was secondary VUR that could also be treated endoscopically with a high success rate. In our opinion, EBD may be considered first-line treatment in POM.

High Pressure Balloon Dilatation of Primary Obstructive Megaureter in Children: A Multicenter Study

Aim of the Study: We described the initial experience of four referral centers in the treatment of primary obstructive megaureter (POM) in children, by high-pressure balloon dilatation (HPBD) of the ureterovesical junction with double JJ stenting. We managed a retrospective multicenter study to assess its effectiveness in long-term. Methods: We reviewed the medical records of all children who underwent HPBD for POM that require surgical treatment from May 2012 to December 2017 in four different institutions. The primary outcome measured was ureterohydronephrosis (UHN) and its degree of improvement after the procedure. Secondary outcomes were postoperative complications and resolution of preoperative symptomatology. Main Results: Forty-two ureters underwent HPBD for POM in 33 children, with a median age of 14.7 months - (range: 3 months -15 years). Ureterohydronephrosis improves in 86% of ureters after one endoscopic treatment. Three cases required a second HPBD. Four patients required surgical treatment for worsening of UHN after endoscopic treatment. The post-operative complication rate was 50% (21 ureters). In 13 cases (61%), they were related to double J stent. The median follow-up was 24 months (2 months -5 years) and all patients were symptom-free. Conclusion: We reported the first multicenter study and the largest series of children treated with HPBD, with an overall success rate of 92%. Endoscopic treatment can be a definitive treatment of POM since it avoided reimplantation in 90% of cases. Complications are mainly due to double J stent.

High pressure balloon dilatation of the ureterovesical junction in primary obstructive megaureter: Infectious morbidity

INTRODUCTION

The objective of this study is to investigate the infectious morbidity associated with high-pressure balloon dilatation (HPBD) and an indwelling double J stent, in primary obstructive megaureter.

METHODS

We reviewed the cases of 12 patients undergoing endoscopic treatment for primary obstructive megaureter from January 2012 to January 2015. The characteristics of the infection and data concerning the patient and the intervention were analyzed.

RESULTS

The frequency of preoperative urinary tract infection (UTI) was 58%. The procedure was feasible in 100% of cases. Two patients required a second dilatation. One patient underwent Cohen's ureteral reimplantation after failure of the second dilatation. The frequency of postoperative UTI was 25%. All these infections occurred in patients with a double J stent. None of the patients had UTI after stent removal. None of the patients developed postoperative vesicoureteral reflux (VUR) after HPBD.

CONCLUSION

Endoscopic balloon dilatation has been shown to have good short- mid- and long-term outcomes. In our experience, the morbidity of this procedure mostly results from infections, exclusively related to the use of a double J stent. The placement of a double J stent has a significant medical and economic impact. A definitive decision about the utility of double J stents will require studies of further dilatation without the placement of a double J stent.

LEVEL OF EVIDENCE

4.

[Therapeutic mega-ureter primitive before one year of life, retrospective study of 20years]

INTRODUCTION

What is the proper way to manage complicated primary mega-ureter in infants under the age of one. This has already been discussed in the literature but the controversy remains.

OBJECTIVE

Evaluate the long-term results of the management of mega-ureter based support under the age of one.

MATERIAL AND METHODS

Single-center retrospective study from 1990 to 2010. All children under one year found were evaluated including clinical examination, ultrasound, scintigraphy and cystography. They were divided into two groups: group 1: children operated on before the age of one year, group 2 non-operated or operated children after the age of one year. We analyzed the long-term evolution of these children on the following criteria: reflux, pyelonephritis, changes in dilation, renal function, need for surgical revision or secondary surgery, and impact on bladder function.

RESULTS

In total, 54 patients were included in group 1 and 56 patients in group 2. In a median follow-up of 12 years. A total of 101 boys and 9 girls (sex-ratio 11.22). There were 57 left MUP (52%), 22 right (20%) and 31 bilateral (28%). A total of 71% of antenatal diagnosis. No difference on the emergence of complications: 25 (group 1) versus 31 (group 2) OR=0.69; 95% (0.307; 1.574); P=0.44. No difference between secondary surgery and revision surgery: group 1=12, group 2=22, OR=0.45; 95% CI (0.17, 1.09); P=0.06. No difference for daytime incontinence: OR=1.04; 95% CI (0.14; 7.64); P=0.67. Seventy-six children (69%) were finally made, 12 children operated twice (10.9%) and 34 children (31%) never made.

CONCLUSION

The main challenge of the MUP of management is the preservation of renal function. Sixty-nine percent of our children received surgery due to impaired renal function lower than 30% of urethral dilatation greater than 10mm associated with reflux or recurrent pyelonephritis. Clinical monitoring, regular ultrasound and isotopic testing are necessary and should be extended to adulthood.

LEVEL OF EVIDENCE

5.

[Laparoscopic ureterovesical repair for megaureter treatment]

BACKGROUND

An alternative treatment for obstructive and refluxing obstructive megaureter with ureterovesical junction maintenance through laparoscopy is proposed.

MATERIAL AND METHODS

The series consists of 8 cases, all of them studied because of prenatal hydronephrosis or febrile urinary tract infection. Seven were diagnosed with obstructive megaureter and one with obstructive refluxing megaureter. The procedure consisted in incising the stenotic portion of the ureter longitudinally and maintaining its posterior wall attached to the bladder, the anterior wall of the ureter was anastomosed transversally to the bladder mucosa in order to liberate the obstruction.

RESULTS

Two of the 8 cases were women and 6 were male. They were aged between 5 months and 11 years (average age of 2.9 years). The surgical time varied between 90 and 120min, with a 48h hospital stay. The permanence of the vesical catheter and the double J stent was of 48h and 6 weeks, respectively. A female patient developed febrile urinary tract infection one week after the surgical procedure. The rest of the patients remained asymptomatic, with normal urinalysis and quarterly urine culture results. Six months after the procedure, the ultrasound showed improvement of the ureteral diameter and of the pyelocaliceal ectasia. The average follow-up was of 2 years.

DISCUSSION

The handling of stenosis with longitudinal incision of the ureter and transverse anastomosis to the bladder mucosa, seems promising. The laparoscopic approach allows to identify clearly the longitude of the stenotic segment and join with relative precision such opening with the one of the vesical mucosa.

Single Versus Double Ureteral Stent Placement After Laser Endoureterotomy for the Management of Benign Ureteral Strictures: A Randomized Clinical Trial

BACKGROUND AND PURPOSE

Endoureterotomy is a viable option for treating patients with benign ureteral stricture. We compared the efficacy and safety of double versus single ureteral stent placement after laser endoureterotomy.

PATIENTS AND METHODS

This study included 55 patients with benign ureteral strictures; all patients underwent retrograde laser endoureterotomy. Patients were randomized either to single or double ureteral stents. Single stents were placed in 27 ureters while double stents were placed in 28 ureters. The stent diameter used was 7 F, and stents were indwelling for 8 weeks. Imaging was performed 1 month after stent removal and repeated regularly every 3 months. Clinical characteristics, operative results, and functional outcomes were compared for strictures managed in both groups. Success was evaluated both subjectively and objectively.

RESULTS

Fifty-five patients with a mean age of 46 (16-75) years had benign ureteral strictures; the mean stricture length was 1.92 (1-3) cm. The mean follow-up was 25.7 (9-42) months. The overall success rate was 67.3% (37 patients) with no radiologic evidence of obstruction, 6 (10.9%) patients showed symptomatic improvement while 12 (21.8%) patients underwent surgical reconstruction. Success was significantly higher for ureteral strictures (>1.5 cm) managed with double stent placement (82.4%), compared with single stent placement (38.9%) with a P value of 0.009.

CONCLUSIONS

Double stent placement of the ureter after laser endoureterotomy achieved a higher success rate compared with single stent placement in cases of benign ureteral strictures. Although ureteral strictures (≤1.5 cm) achieved better outcome after laser endoureterotomy, strictures (>1.5 cm) favored better with double stent versus single stent placement.

Can endoscopic balloon dilation for primary obstructive megaureter be effective in a long-term follow-up?

BACKGROUND

Ureteral tapering and reimplantation is an established treatment for persistent or progressive primary obstructive megaureter (POM) but may result in complications and morbidity. Use of a less invasive technique involving endoscopic balloon dilation appears very interesting.

OBJECTIVE

The objective of this report is to determine if endoscopic balloon dilation for POM is effective in the long term as well as to assess complications of the procedure.

MATERIAL AND METHODS

A retrospective review was done on 19 patients and 20 ureters treated with the endoscopic balloon dilation by POM from June 2000 to February 2010. Surgery was performed solely in those cases in which there was persistence of obstruction in the renogram along with one or all of the following conditions: impairment of the differential renal function <40%, worsening of the renal pelvic dilation, febrile UTI in spite of antibiotic prophylaxis or renal calculi. The patients comprised 16 boys and 3 girls with a mean age at surgery of 17 months (range 1-44 months). Ten cases were left sided, eight right sided, and one bilateral. Under endoscopic and fluoroscopic guidance, a 3-5 Fr dilating balloon was inflated to 12-14 atm, or until disappearance of the stenotic obstructive area. A double J stent was positioned and withdrawn 2 months later. Follow-up recorded the presence of symptoms, number of reintervention procedures registered, and included renal ultrasound and MAG-3 renogram.

RESULTS

There were no perioperative complications. Eighteen ureters showed a non-obstructive pattern on MAG-3 renogram after the first endoscopic dilation, representing a 90% success rate. One case required a second dilation, which proved successful and two cases of recurrent lithiasis required ureterotomy without instances of obstruction. 2 patients had a febrile UTI and a vesicoureteral reflux was diagnosed in one. Renal function was preserved in 95% of patients. The mean follow-up was 6.9 years (range 3.9-13.3 years). One patient was lost after the procedure.

DISCUSSION

In an era of minimally invasive techniques, the search for less invasive procedures for treatment of POM has resulted in a variety of surgical options. Angulo et al., in 1998 and our group described the first POM treatment with endoscopic balloon dilation, which is believed to be a definitive, less invasive, and safe treatment. Furthermore, should an endoscopic approach fail, reimplant surgery can be performed. Few publications have reported short series with good results in the short and medium term. Torino et al. presented five cases in children aged less than 1 year, none of these showed evidence of obstruction. García-Aparicio et al. presented a series of 13 patients treated with a success rate of 84.6%. Christman et al. added laser incision in cases of narrowed ureteral segment 2-3 cm long and used double stenting. Good outcomes were presented in 71%. Romero et al. reported improvement of drainage within the first 18 months after treatment in 69% of patients. The potential de novo onset of vesicoureteral reflux may be the source of some controversy. We consider that dilation does not significantly alter the antireflux mechanism. In VCUG is not systematically performed because it is an invasive test. This restricts the conclusions that can be drawn from our findings. Nevertheless, some groups continue to systematically perform VCUG.

CONCLUSIONS

Endoscopic balloon dilation for POM is a safe, feasible, and less invasive procedure that shows good outcomes on long-term follow-up. However, multicenter studies and prospective trials should be encouraged to provide more definitive evidence on its benefits.

Ureteral complications after renal transplant in children: timing of presentation, and their open and endoscopic management

We retrospectively reviewed the records of 24 consecutive patients undergoing treatment for ureteral complications after RTx in the period 2001-2012 to determine the timing of presentation of the complications, and their open or endoscopic management. Three patients (12%) had a necrosis of the transplanted ureter soon after RTx. All required open urinary diversion in a native ureter. Ten cases (42%) developed ureteral obstruction. Time of presentation was variable mainly in relation to the underlying cause. Endoscopic treatment was successful in two cases with urinary stones and open surgery in two with mid-ureteral obstruction. Six patients had VUJ stenosis, three underwent open reimplantation, whereas temporary double-J stent placement was successfully performed in the remainder. Eleven patients (46%) had VUR. It seldom presented in the first year after RTx. Endoscopic treatment was attempted in all and was successful in all the six cases without vs. only one of the five with lower urinary tract pathology (p = 0.01). Endoscopic treatment is an option in patients with VUR in the absence of lower urinary tract pathology. It is an option also for the treatment of stones and can be attempted in case of VUJ stenosis. Ureteral necrosis always requires open treatment.

Current status of minimally invasive endoscopic management of ureteric strictures

Endourological techniques are used more often nowadays in the treatment of ureteric strictures of various etiologies. Advances in technology have provided new tools to the armamentarium of the endoscopic urological surgeon. Numerous studies exist that investigate the efficiency and safety of each of the therapeutic modalities available. In this review, we attempt to demonstrate the available and contemporary evidence supporting each minimally invasive modality in the management of ureteric strictures.

Use of high-pressure balloon dilatation of the ureterovesical junction instead of ureteral reimplantation to treat primary obstructive megaureter: is it justified?

OBJECTIVE

To compare outcomes between high-pressure balloon dilatation of the ureterovesical junction (UVJ) and ureteral reimplantation with ureteral tapering to treat primary obstructive megaureter (POM).

PATIENTS AND METHODS

Retrospective review of clinical data from patients who underwent surgical treatment of POM from 2005 to 2010. Patients were divided into two groups: endoscopic treatment (ET) with UVJ dilatation and ureteral reimplantation (UR) with Cohen's or Leadbetter-Politano neoureterocystostomy and Hendren's tapering. Preoperative studies included ultrasound scan (US), voiding cystourethrography, and diuretic isotopic renogram. Outcome parameters were US, differential renal function (DRF), presence of postoperative vesicoureteral reflux, need for secondary reimplantation and complications.

RESULTS ET

13 patients with a median age of 7 (4-24) months; UR: 12 patients with a median age of 14 (7-84) months, with no statistical differences in age and gender between groups. Preoperative US parameters were similar. ET: mean diameter of renal pelvis, calices and ureter was 23.5 mm, 13.46 mm and 15.77 mm respectively. UR: mean diameter of renal pelvis, calices and ureter was 22.25 mm, 11.75 mm, and 19.08 mm, respectively. Preoperative DRF was 45.62% and 39.33% for ET and UR, respectively (p > 0.05). Significant improvement of hydroureteronephrosis was observed in 11/13 patients of ET and 11/12 patients of UR (p > 0.05). Postoperative DRF was 42% and 48% for ET and UR, respectively (p > 0.05). Postoperative vesicoureteral reflux was observed in 2 patients of ET and 1 of UR (p > 0.05). Secondary ureteral reimplantation was needed in 3 patients of ET and 2 of UR (p > 0.05).

CONCLUSION

Endoscopic treatment of POM is as effective as ureteral reimplantation but further randomized clinical trials are needed to support these results.

Endoscopic treatment of ureterovesical junction obstructive pathology: A description of the oblique meatotomy technique and results

BACKGROUND

Benign obstructive pathology of the ureterovesical junction includes congenital and acquired illnesses. The objective of this study was to describe the endoscopic oblique meatotomy technique using scissors and cold cutting to treat benign obstructive pathology of the ureterovesical junction.

METHODS

From 2007 to 2012, we treated 18 patients with obstructive pathology of the ureterovesical junction (5 megaureters [3 with lithiasis], 4 iatrogenic stenoses, and 9 ureteroceles with lithiasis). In all cases, oblique meatotomy was performed using endoscopic scissors through an 8.5 Ch ureteroscope. The mean follow-up for all patients was 3 years. Pain, grade of hydronephrosis, and occurrence of vesicoureteral reflux were evaluated before and after treatment.

RESULTS

The mean endoscopic treatment time was 13.4 minutes. The procedure was performed on an outpatient basis with 6 hours of hospital admission, and a double J stent was inserted for 6 weeks. We achieved treatment success in 94.5% of patients after 3 years of follow-up. Only 1 patient presented with vesicoureteral reflux at 12 months after treatment; however, this condition did not require further treatment. Overall, 100% of patients remained free from lithiasis. There are 2 main limitations: the small number of patients and the lack of another group to compare the results of this technique; however, the aim of this work was to communicate a new technique to treat ureterovesical junction stricture.

INTERPRETATION

Oblique ureteral meatotomy is a safe and effective treatment for benign obstructive pathology of the ureterovesical junction and has a low index of complications.

Resolution of primary non-refluxing megaureter: an observational study

AIM

A prospective review of conservative management of primary non-refluxing megaureters (PM) was performed to determine the time taken for resolution (TTR) and complications.

MATERIAL AND METHODS

Patient details were obtained from a prospectively maintained database from January 1, 2003, to December 31, 2011. The clinical features of USS and MAG3 findings were analyzed. All had annual USS and MAG 3 scans two yearly (and whenever necessary).

RESULTS

Fifty ureteric units (UU) in forty-four patients (six bilateral) were studied. There were thirty-three (75%) males. In the unilateral PM, 22/38 were left-sided. Children were classified according to the lower ureteric diameter (UD) into two groups: Group A (Gp A) UD < 10 mm (n=25, 26 UU), and Group B (Gp B) UD ≥ 10 mm (n=19, 24 UU). Antenatal diagnosis was achieved in 21 (84%) UU in Gp A and 11 UU (58%) in Gp B. In Grp A, the median presenting UD was 6 (range 4-9) mm, and 76% resolved completely over a median duration of 60 (18-204)months. In Grp B, the median UD was 15 (10-27)mm, and 17% resolved completely over a median duration of 102 (42-210) months. Two developed ureteric calculi (removed ureteroscopically). Three with complications (obstructive drainage pattern in MAG 3 with decreasing function and debilitating infections) underwent ureteric tapering and reimplantation. An obstructed megaureter resolved after endoscopic dilatation. Another underwent temporary ureterostomy on developing hypertension.

CONCLUSION

The exclusively conservative management of PM seems highly successful within Group A (i.e. UD <10 mm). Complications (stones, decreasing renal function) were more common with higher UD. TTR seems to take over five years in both groups.